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1.
ESMO Open ; 7(1): 100339, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34953404

RESUMO

The coronavirus disease-19 (COVID-19) pandemic promises to have lasting impacts on cancer clinical trials that could lead to faster patient access to new treatments. In this article, an international panel of oncology experts discusses the lasting impacts of the pandemic on oncology clinical trials and proposes solutions for clinical trial stakeholders, with the support of recent data on worldwide clinical trials collected by IQVIA. These lasting impacts and proposed solutions encompass three topic areas. Firstly, acceleration and implementation of new operational approaches to oncology trials with patient-centric, fully decentralized virtual approaches that include remote assessments via telemedicine and remote devices. Geographical differences in the uptake of remote technology, including telemedicine, are discussed in the article, focusing on the impact of the local adoption of new operational approaches. Secondly, innovative clinical trials. The pandemic has highlighted the need for new trial designs that accelerate research and limit risks and burden for patients while driving optimization of clinical trial objectives and endpoints, while testing is being minimized. Areas of considerations for clinical trial stakeholders are discussed in detail. In addition, the COVID-19 pandemic has exposed the underrepresentation of minority groups in clinical trials; the approach for oncology clinical trials to improve generalizability of efficacy and outcomes data is discussed. Thirdly, a new problem-focused collaborative framework between oncology trial stakeholders, including decision makers, to leverage and further accelerate the innovative approaches in clinical research developed during the COVID-19 pandemic. This could shorten timelines for patient access to new treatments by addressing the cultural and technological barriers to adopting new operational approaches and innovative clinical trials. The role of the different stakeholders is described, with the aim of making COVID-19 a catalyst for positive change in oncology clinical research and eventually in cancer care.


Assuntos
COVID-19 , Neoplasias , Telemedicina , Ensaios Clínicos como Assunto , Humanos , Neoplasias/epidemiologia , Neoplasias/terapia , Pandemias , SARS-CoV-2
2.
Cancer Chemother Pharmacol ; 66(2): 389-94, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20480279

RESUMO

PURPOSE: Brostallicin is a DNA minor groove binder which shows enhanced antitumor activity in cells which are resistant to several anticancer agents due to their high glutathione S-transferase (GST)/glutathione content. Phase I and II clinical trials of single-agent brostallicin have shown that myelotoxicity is the dose-limiting toxicity (DLT), while hints of antitumor activity were mainly observed in soft tissue sarcoma. Preclinical studies showing a more than additive antitumor effect of the cisplatin-brostallicin combination paved the way to clinical combination studies. In particular, we set up the first clinical combination study of brostallicin and cisplatin in patients with advanced solid tumors. This study was to be followed by a phase II study in patients with recurrent squamous cell carcinoma of the head and neck (SCCHN). METHODS: Escalating doses of brostallicin were administered in combination with a fixed dose of cisplatin (75 mg/m(2)) in patients with recurrent or metastatic advanced solid tumors who had previously received a cumulative dose of cisplatin not higher than 475 mg/m(2). The recommended dose of brostallicin was expanded in order to have a better estimate of antitumor activity and to better define the safety profile of the combination. RESULTS: Twenty-one patients were treated. Two DLTs (grade 3 fatigue and febrile neutropenia) were observed at dose level 3 (brostallicin 9 mg/m(2)). Dose level 2 (brostallicin 7 mg/m(2) and cisplatin 75 mg/m(2)) was recommended for future phase II studies. Main toxicity was hematologic; in fact, only 1 patient out of 21 did not develop neutropenia and only 2 patients did not have thrombocytopenia. Grade 3-4 neutropenia was observed in 90.5% of patients, grade 3-4 thrombocytopenia in 38.1%, grade 3-4 anemia in 23.8%. The cycle 1 nadir (ANC < 500 x 10(9)/L) for neutrophils was Day 14 (median; range 11-17) with recovery to an ANC of >1,500 3.5 days after nadir (median; range 2-4) at dose level 3. The cycle 1 nadir (median of 51,000 x 10(9)/L) for platelets occurred on Day 13 (median; range 10-15) with recovery to a platelet count of >100,000 4 days after nadir (median; range 2-8). No objective responses were observed, but seven patients had a long lasting (>18 weeks) stable disease. CONCLUSIONS: Further studies of the combination of brostallicin and cisplatin are warranted.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias/tratamento farmacológico , Idoso , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Cisplatino/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Guanidinas/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Pirróis/administração & dosagem , Caracteres Sexuais
3.
J Clin Oncol ; 19(15): 3456-62, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-11481350

RESUMO

PURPOSE: To investigate the sequence effect of irinotecan and a 48-hour infusion of fluorouracil (5-FU) modulated by leucovorin (LV) on the plasma pharmacokinetics of irinotecan and its metabolites, the toxicity profile of this combination, and irinotecan's maximum-tolerated dose (MTD). PATIENTS AND METHODS: Thirty-three metastatic colorectal cancer patients were randomized to receive a 60-minute infusion of irinotecan before or after a 48-hour infusion of 5-FU modulated by LV. The reverse sequence was used after 21 days for the second cycle. 5-FU 3,500 mg/m2 was preceded by l-LV 250 mg/m2. Irinotecan 150 mg/m2 (starting dose) was administered to the first three patients. The dose was escalated by 50 mg/m2 in subsequent groups of three to six patients to determine the MTD for both sequences. Pharmacokinetic analysis of irinotecan and its metabolites was performed after each cycle. RESULTS: Toxicities were affected by the sequence of administration of irinotecan and 5-FU, with an improved tolerability for irinotecan followed by 5-FU. The irinotecan MTD was reached at 300 mg/m2 when irinotecan followed 5-FU and at 450 mg/m2 when it preceded 5-FU. In seven of 23 patients who received both sequences at identical irinotecan doses, the dose-limiting toxicity was observed only when irinotecan followed 5-FU. Pharmacokinetic analysis revealed that the administration sequence significantly affected the SN-38 area under the concentration-versus-time curve (AUC), which was 40.1% lower (P <.05) when irinotecan preceded 5-FU. CONCLUSION: The sequence of treatment with irinotecan and infusional 5-FU affects the tolerability of this combination. This can be explained in part by a reduced SN-38 AUC when irinotecan preceded infusional 5-FU. Well-defined 5-FU/irinotecan regimens are needed because the administration sequence or the interval between the agents might affect treatment tolerance and perhaps also activity.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Camptotecina/farmacocinética , Neoplasias Colorretais/tratamento farmacológico , Fluoruracila/farmacologia , Adenocarcinoma/metabolismo , Adulto , Idoso , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Camptotecina/administração & dosagem , Camptotecina/efeitos adversos , Camptotecina/análogos & derivados , Neoplasias Colorretais/metabolismo , Esquema de Medicação , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/farmacocinética , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Infusões Intravenosas , Irinotecano , Leucovorina/administração & dosagem , Leucovorina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica
4.
J Clin Oncol ; 19(8): 2213-21, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11304774

RESUMO

PURPOSE: To evaluate whether an accelerated-intensified cyclophosphamide, epirubicin, and fluorouracil (CEF) chemotherapy regimen with the support of granulocyte colony-stimulating factor (G-CSF) induces a higher activity and efficacy compared with standard CEF in metastatic breast cancer patients. PATIENTS AND METHODS: Stage IV breast cancer patients were randomized to receive as first-line chemotherapy either standard CEF (cyclophosphamide 600 mg/m(2), epirubicin 60 mg/m(2), and fluorouracil 600 mg/m(2)) administered every 21 days (CEF21) or accelerated-intensified CEF (cyclophosphamide 1,000 mg/m(2), epirubicin 80 mg/m(2), and fluorouracil 600 mg/m(2)) administered every 14 days (HD-CEF14) with the support of G-CSF. Treatment was administered for eight cycles. RESULTS: A total of 151 patients were randomized (74 patients on the CEF21 arm and 77 on the HD-CEF14 arm). In both arms, the median number of administered cycles was eight. The dose-intensity actually administered was 93% and 86% of that planned, in CEF21- and HD-CEF14-treated patients, respectively. Compared with the CEF21 arm, the dose-intensity increase in the HD-CEF14 arm was 80%. Both nonhematologic and hematologic toxicities were higher in the HD-CEF14 arm than in the CEF21 arm. During chemotherapy, four deaths occurred in the HD-CEF14 arm. No difference in overall response rate (complete plus partial responses) was observed: 49% and 51% in the CEF21 and HD-CEF14 arms, respectively (P =.94). A slightly non-statistically significant higher percentage of complete response was observed in the HD-CEF14 arm (20% v 15%). No difference in efficacy was observed. The median time to progression was 14.3 and 12.8 months in the CEF21 and HD-CEF14 arms, respectively (P =.69). Median overall survival was 32.7 and 27.2 months in the CEF21 and HD-CEF14 arms, respectively (P =.16). CONCLUSION: In metastatic breast cancer patients, an 80% increase in dose-intensity of the CEF regimen, obtained by both acceleration and dose intensification, does not improve the activity and the efficacy compared with a standard dose-intensity CEF regimen.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias da Mama/patologia , Ciclofosfamida/administração & dosagem , Progressão da Doença , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Epirubicina/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Resultado do Tratamento
5.
Cancer ; 91(4): 712-20, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11241238

RESUMO

BACKGROUND: Irinotecan (CPT-11) is an active drug in the treatment of patients with advanced colorectal carcinoma. The infusion of 5-fluorouracil (5-FU) according to circadian rhythms was used previously to decrease toxicity and to increase its therapeutic efficacy. The objective of this study was to establish the maximum tolerated dose (MTD) of CPT-11 together with a chronomodulated infusion of 5-FU and the l-form of folinic acid (FA). Secondary end points were the assessment of activity and quality of life (QoL). METHODS: Twenty-six patients with advanced colorectal carcinoma who had received previous treatment with 5-FU were entered on this Phase I study. At least three patients were recruited at each dose level. The CPT-11 starting dose was 175 mg/m(2) on Day 1 with an increase of 50 mg/m2 per dose level. A daily administration of chronomodulated 5-FU (900 mg/m2; peak delivery rate at 04:00) and FA (175 mg/m2; peak delivery rate at 04:00) for 5 days every 3 weeks was given with CPT-11. After the first three patients, the 5-FU dose was reduced to 700 mg/m2 per day due to toxicity. No intrapatient dose escalation was allowed. RESULTS: One hundred sixty-one courses were delivered. Dose-limiting toxicity was observed during the first course in seven patients (27%). Four patients developed neutropenia, with one patient reporting febrile neutropenia, two patients reporting severe stomatitis, and six patients reporting severe diarrhea. CPT-11 MTD was reached at 350 mg/m2 when a toxic death was observed with a recommended dose of 325 mg/m2. Six partial responses were observed (23%). The median duration of response and the progression free and overall survival rates were 199 days, 175 days, and 359 days, respectively. QoL was not affected by the treatment. CONCLUSIONS: The recommended dose for Phase II trials is 325 mg/m2 CPT-11 on Day 1, which is similar to the dose given as a single agent, together with a 5-day chronomodulated infusion of 700 mg/m2 5-FU and 175 mg/m2 FA. Intensification of this schedule every 2 weeks should be achievable.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Camptotecina/análogos & derivados , Cronoterapia , Neoplasias Colorretais/tratamento farmacológico , Adulto , Idoso , Camptotecina/administração & dosagem , Neoplasias Colorretais/patologia , Feminino , Fluoruracila/administração & dosagem , Humanos , Irinotecano , Leucovorina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Qualidade de Vida
6.
Ann Oncol ; 10(8): 915-21, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10509152

RESUMO

OBJECTIVES: To determine the maximum tolerable doses (MTDs) of irinotecan (CPT-11) and 5-fluorouracil (5-FU) plus levofolinic acid (LFA) administered together every two weeks, to define the toxicity profile of this regimen, and to have a preliminary evidence of its activity in the first-line management of advanced colorectal cancer patients. PATIENTS AND METHODS: Patients with histologically proven colorectal carcinoma, no prior chemotherapy for their advanced disease, and with at least one measurable or evaluable indicator lesion, were admitted to this study. The starting dose of CPT-11 was 150 mg/m2 given i.v. (90 min infusion) on day 1, followed on day 2 by a fixed dose of LFA (250 mg/m2) as a two-hour i.v. infusion plus a starting dose of 5-FU 600 mg/m2 as i.v. bolus. No intra-patient dose escalation was allowed. If no dose limiting toxicity (DLT) was observed among three patients of each cohort, CPT-11 and 5-FU were alternately escalated in the subsequent cohort. Otherwise, three more patients were enrolled at the same dose level. DLT was defined as: WHO grade 3 non-haematological toxicity (except for vomiting or alopecia), grade 3 febrile neutropenia, grade 4 neutro- or thombocytopenia, or a > 2-week delay in recycling. The MTDs were defined as the doses at which two of three, or four of six, patients showed the same DLT. RESULTS: Thirty-one patients (five pretreated in adjuvant setting) were enrolled in this study, and a total number of 293 cycles (median 6/patient) were administered. Dose escalation safely proceeded to 210/950/250 mg/m2 of CPT-11/5-FU/LFA. These dosages were considered as MTDs, since four of six patients showed grade 4 neutropenia, in one case associated with grade 3 stomatitis. A mild decrease of both the CPT-11 and 5-FU doses to 200 and 850 mg/m2, respectively, caused different DLTs (neutropenia and diarrhoea) in two out of seven patients. At these dosages, transient grades 3 or 4 neutropenia affected two patients each during their treatment, while only one patient suffered from a severe delayed diarrhoea. Other non-haematological toxicities were mild and manageable. Therefore, we recommend this latter dose level for further study. Major responses (3 complete and 11 partial) were reported in 14 patients, for an overall response rate of 45% (95% CI: 27%-64%) according to an intent-to-treat analysis. Responses were observed from first dose level, and in four of five previously treated patients. Median failure-free and overall survivals, after a median follow-up of 39 weeks, were 42 and 55 weeks, respectively. CONCLUSIONS: The concurrent administration of CPT-11 and modulated 5-FU every two weeks is feasible at the recommended dosages. This regimen demonstrated interesting activity in the management of advanced colorectal cancer patients, and it probably better exploits the synergism between CPT-11 and 5-FU than recently tested alternating schedules. A phase II study is ongoing to more precisely define its activity and toxicity.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Leucovorina/administração & dosagem , Adenocarcinoma/diagnóstico , Adenocarcinoma/mortalidade , Adulto , Idoso , Antimetabólitos Antineoplásicos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/mortalidade , Intervalos de Confiança , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Fluoruracila/administração & dosagem , Humanos , Irinotecano , Masculino , Pessoa de Meia-Idade , Prognóstico , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do Tratamento
7.
Acta Otolaryngol ; 119(1): 42-7, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10219383

RESUMO

The various effects of ageing on the auditory system, collectively termed presbycusis, are being studied across a wide range of animal species, including humans. One contributing factor to presbycusis is thought to be losses of the sensory hair cells in the cochlea. In this study, hair cell counts were obtained from cochleas of pigmented guinea pigs (Cavia porcellus) at ages ranging from 11 days to 4 years 7 months, using scanning electron microscopy to visualize the organ of Corti. Representative samples of the basal, middle and apical turn of the cochlea were photographed for analysis. Hair cell loss was observed, even in young animals. However, the loss was greater in the aged animals, but was not distributed evenly throughout the length of the cochlea. No significant loss of hair cells was seen in the basal (high frequency) or middle turn of the cochlea of the aged animals. In the apical (low frequency) turn, there was a significant loss of hair cells in all rows of outer hair cells (up to around 20%), and was most severe in the third row. There was no loss of apical inner hair cells in the aged animals.


Assuntos
Envelhecimento/patologia , Células Ciliadas Auditivas/ultraestrutura , Presbiacusia/etiologia , Animais , Contagem de Células , Cóclea/patologia , Cobaias , Células Ciliadas Auditivas/patologia , Microscopia Eletrônica de Varredura , Presbiacusia/patologia
8.
Acta Otolaryngol ; 118(5): 673-80, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9840503

RESUMO

The auditory brainstem response (ABR) technique was used to investigate potential dysfunctions in the auditory brainstem of the pigmented guinea pig (Cavia porcellus) associated with biological ageing. Animals aged from 58 days to 4 years 3 months were tested. ABRs were recorded at stimulation intensities from 85 dB HL to -10 dB HL. The auditory thresholds were found to undergo marked elevations in old animals, by an average of 32 dB. From the traces obtained, four positive deflection waves were reliably recorded. The latency of each of the four waves was evaluated at different stimulation intensities in guinea pigs of different ages. Although there was a trend for the latencies to increase in old age, these differences were not statistically significant. Similarly, there were no significant age-related changes in the inter-peak intervals. The latency/intensity functions of the four waves produced parallel curves. However, the curve from the old age group was shifted to the right, by an average of 35 dB, indicative of conductive hearing loss. There was no evidence of retro-cochlear hearing loss. Therefore, it appears that the threshold elevations in the old animals can be accounted for by conductive hearing loss, presumably in the middle ear. In 24% of the old animals tested, no ABR could be elicited. It would appear that these animals had suffered severe sensorineural hearing loss.


Assuntos
Envelhecimento/fisiologia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Análise de Variância , Animais , Eletrodos , Eletrofisiologia/instrumentação , Eletrofisiologia/métodos , Eletrofisiologia/estatística & dados numéricos , Cobaias , Presbiacusia/fisiopatologia , Estatísticas não Paramétricas
9.
J Infect ; 36(1): 73-7, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9515673

RESUMO

Acute changes in the electrophysiology and ultrastructure of the organ of Corti were studied after microperfusion of c. 5 x 10(6) CFU of serotype 2 Streptococcus pneumoniae D39 or Escherichia coli K-12 directly into the scala tympani of guinea pigs. Hearing loss was assessed by recording the auditory nerve compound action potential response to a 10 kHz tone pip. Mean hearing loss 3 h after pneumococcal perfusion (n = 4) was 44 dB, compared to 6 dB after E. coli perfusion (n = 4) (P<0.001). After pneumococcal perfusion, scanning electron microscopy revealed damage to hair cell stereocilia and cratering of the apical surface of supporting cells. Intraperitoneal injection of 100 mg/kg cefotaxime (n = 4) or 100 mg/kg amoxycillin (n = 4) 30 min before perfusion of pneumococci significantly reduced mean hearing loss to 23 dB (P=0.01) or 20 dB (P=0.01), respectively, and diminished ultrastructural damage. The data suggest that if pneumococci invade the inner ear during meningitis, cochlear deafness may rapidly ensue.


Assuntos
Amoxicilina/uso terapêutico , Antibioticoprofilaxia , Cefotaxima/uso terapêutico , Cefalosporinas/uso terapêutico , Penicilinas/uso terapêutico , Infecções Pneumocócicas/tratamento farmacológico , Rampa do Tímpano/microbiologia , Streptococcus pneumoniae/patogenicidade , Animais , Otopatias/complicações , Otopatias/patologia , Otopatias/prevenção & controle , Eletrofisiologia , Escherichia coli/patogenicidade , Infecções por Escherichia coli/tratamento farmacológico , Cobaias , Células Ciliadas Auditivas/patologia , Células Ciliadas Auditivas/ultraestrutura , Perda Auditiva Central/microbiologia , Microscopia Eletrônica de Varredura , Infecções Pneumocócicas/prevenção & controle
10.
Infect Immun ; 65(11): 4411-8, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9353013

RESUMO

We investigated the roles of pneumolysin and neuraminidase in the pathogenesis of deafness and cochlear damage during experimental pneumococcal meningitis. Anesthetized guinea pigs were inoculated intracranially with 7.5 log10 CFU of either (i) wild-type Streptococcus pneumoniae D39 (n = 8), (ii) PLN-A, a defined isogenic derivative of D39 deficient in pneumolysin (n = 5), or (iii) deltaNA1, a new derivative of D39 deficient in neuraminidase constructed by insertion-duplication mutagenesis of the nanA gene (n = 5). To quantify hearing loss, the auditory nerve compound action potential evoked by a tone pulse was recorded from the round window membrane of the cochlea every 3 h for 12 h. The organ of Corti was intravitally fixed for subsequent examination by high-resolution scanning and transmission electron microscopy. All animals sustained similar meningeal inflammatory responses. PLN-A induced significantly less hearing loss than D39 over the frequency range of 3 to 10 kHz. Levels of mean hearing loss at 10 kHz 12 h postinoculation were as follows: D39, 50 dB; deltaNA1, 52 dB (P = 0.76 versus D39), and PLN-A, 12 dB (P < 0.0001 versus D39). The mean rates of hearing loss at 10 kHz were 4.4 dB/h for D39, 4.3 dB/h for deltaNA1, and just 1.0 dB/h for PLN-A (P < 0.0001 versus D39). Suppurative labyrinthitis was universal. PLN-A induced the accumulation of less protein in the cerebrospinal fluid (P = 0.04 versus D39). Infection with D39 and deltaNA1 induced significant damage to the reticular lamina, the sensory hair cells, and supporting cells of the organ of Corti. By contrast, after infection with PLN-A, the organ of Corti appeared virtually intact. Pneumolysin seems to be the principal cause of cochlear damage in this model of meningogenic deafness. No clear pathogenic role was demonstrated for neuraminidase.


Assuntos
Cóclea/ultraestrutura , Surdez/etiologia , Meningite Pneumocócica/complicações , Neuraminidase/toxicidade , Estreptolisinas/toxicidade , Animais , Proteínas de Bactérias , Feminino , Cobaias , Masculino , Meningite Pneumocócica/patologia , Microscopia Eletrônica de Varredura
11.
Acta Otolaryngol ; 117(3): 329-36, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9199517

RESUMO

Microperfusion of scala tympani with the NO donors, sodium nitroprusside (SNP) and S-nitroso-N-acetylpenicillamine (SNAP), produced marked depression of the compound action potential (CAP) and cochlear microphonic (CM) together with severe and widespread morphological damage to hair cells and supporting cells in the organ of Corti. In addition, direct perfusion of N-methyl-D-aspartate (NMDA) into scala tympani, which probably induces excess stimulation of NMDA receptors within the cochlea and which is known to lead to the release of NO, was found to elicit similar electrophysiological and structural lesions in the cochlea. Pre-perfusion of scala tympani with L-methyl arginine (L-MA), which inhibits the release of NO, or superoxide dismutase (SOD), an O2-scavenger, conferred marked protection upon the cochlea from the lesions caused by NO donors. These observations indicate that enhanced NO production is likely to be an important factor responsible for pathological insult of the cochlea. The possibility is discussed that this factor is involved in the chain of events leading to hearing loss caused by bacterial meningitis. Such hearing loss is a major sequela of bacterial meningitis in children.


Assuntos
Cóclea/fisiologia , Perda Auditiva Neurossensorial/etiologia , Meningites Bacterianas/complicações , Óxido Nítrico/fisiologia , Potenciais de Ação/efeitos dos fármacos , Animais , Cóclea/ultraestrutura , Potenciais Microfônicos da Cóclea/efeitos dos fármacos , Potenciais Microfônicos da Cóclea/fisiologia , Inibidores Enzimáticos/farmacologia , Cobaias , Perda Auditiva Neurossensorial/metabolismo , Meningites Bacterianas/metabolismo , Microscopia Eletrônica de Varredura , N-Metilaspartato/farmacologia , Óxido Nítrico/agonistas , Óxido Nítrico/antagonistas & inibidores , Nitroprussiato/farmacologia , Penicilamina/análogos & derivados , Penicilamina/farmacologia , S-Nitroso-N-Acetilpenicilamina , Rampa do Tímpano/efeitos dos fármacos , Rampa do Tímpano/ultraestrutura , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores
12.
Acta Otolaryngol ; 116(3): 401-7, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8790739

RESUMO

Experimental meningitis was induced in 16 pigmented guinea pigs by subarachnoid inoculation of mid log-phase 1 x 10(9) E. coli K-12 (n = 8) or 5 x 10(7) Streptococcus pneumoniae type 2 (n = 8). Animals were killed at various times between 3 and 12 h after inoculation and the ultrastructure of the organ of Corti (including the basilar membrane) was examined with high resolution scanning electron microscopy. Both E. coli and S. pneumoniae induced meningitis and invaded scala tympani. In both types of meningitis the apical surface of inner supporting cells developed craters. inner hair cell stereocilia were also disrupted. In pneumococcal meningitis both these lesions were more pronounced but in addition there were breaks in the junctions between inner hair cells and their adjacent supporting cells and there was ballooning and rupture of the apical surface of outer hair cells. Damage to the organ of Corti after bacterial invasion of the inner ear may be one of the mechanisms by which bacterial meningitis can cause deafness. The more severe cochlear lesions induced by S.pneumoniae may explain the higher incidence of deafness after pneumococcal meningitis.


Assuntos
Escherichia coli/patogenicidade , Meningite Pneumocócica/líquido cefalorraquidiano , Órgão Espiral/ultraestrutura , Animais , Surdez/etiologia , Feminino , Cobaias , Masculino , Meningite Pneumocócica/complicações , Meningite Pneumocócica/etiologia , Microscopia Eletrônica , Órgão Espiral/microbiologia , Órgão Espiral/fisiopatologia , Streptococcus pneumoniae/patogenicidade , Membrana Timpânica/ultraestrutura
13.
Int J Exp Pathol ; 76(5): 317-30, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7488546

RESUMO

Sensorineural hearing loss was studied in a rabbit model of experimental bacterial meningitis using electrophysiological and ultrastructural techniques. Hearing impairment was monitored by auditory brain-stem evoked responses (ABERs) and concomitant structural lesions were identified by both transmission (TEM) and scanning (SEM) electron microscopy. Meningitis was induced by intra-cerebrospinal fluid injection of either Escherichia coli (strain 2073 and type K-12) or Haemophilus influenzae type b. Auditory loss of approximately equal to 10 dB occurred in all rabbits by about 10 hours post infection and progressed in severity until by 20 h following infection, hearing losses up to and > 60 dB were obtained. At levels of hearing loss < 20 dB ultrastructural damage to the organ of Corti was barely detectable. With greater levels of hearing loss, patchy structural damage to hair cells, synaptic nerve terminals, supporting cells and inner spiral sulcus cells and cells of the stria vascularis was clearly evident. Bacteria were found in scala tympani, the basilar membrane, the organ of Corti, scala media, the spiral ligament and at the margin of the stria vascularis. Evidence of bleeding was found in some cochleas; erythrocytes were found in scala tympani, scala media, amongst hair cells and beneath the tectorial membrane. The results show that hearing loss is associated with bacterial invasion and damage to the organ of Corti and that the cause of hearing loss is likely to result from multiple lesions within the cochlea. Lesions to sensory cells almost certainly will produce permanent hearing loss. Lesions to supporting cells, nerve terminals and to stria vascularis may well produce only temporary hearing loss.


Assuntos
Cóclea/microbiologia , Cóclea/ultraestrutura , Perda Auditiva Neurossensorial/microbiologia , Meningites Bacterianas/complicações , Animais , Infecções por Escherichia coli/complicações , Potenciais Evocados Auditivos do Tronco Encefálico , Infecções por Haemophilus/complicações , Haemophilus influenzae , Perda Auditiva Neurossensorial/patologia , Perda Auditiva Neurossensorial/fisiopatologia , Meningites Bacterianas/patologia , Meningites Bacterianas/fisiopatologia , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Coelhos
14.
Acta Otolaryngol ; 115(3): 386-91, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7544527

RESUMO

Sensorineural hearing loss is a major sequela of the bacterial meningitis associated in particular with Streptococcus pneumoniae. Recent studies have shown pneumolysin, a toxin elaborated by S. pneumoniae, to be cytotoxic to the guinea pig cochlea. The mechanisms of this cytotoxicity are, however, not fully understood. In the present study this deleterious action of pneumolysin has been shown to be blocked by pretreating the cochlea with NG-methyl-L-arginine, a known inhibitor of nitric oxide synthesis. Furthermore, pretreatment of the cochlea with MK-801, an NMDA receptor antagonist, was also found to confer marked protection from the action of pneumolysin. This latter finding is consistent with previous reports that excess stimulation of NMDA receptors within the cochlea, an event known to lead to excess nitric oxide release, have similar effects on the cochlea as pneumolysin perfusion. It would therefore appear that nitric oxide may represent a significant link in the chain of events leading to the deafness of bacterial meningitis.


Assuntos
Arginina/análogos & derivados , Cóclea/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Estreptolisinas/toxicidade , Potenciais de Ação/efeitos dos fármacos , Aminoácido Oxirredutases/antagonistas & inibidores , Animais , Arginina/farmacologia , Proteínas de Bactérias , Cóclea/fisiologia , Cóclea/ultraestrutura , Potenciais Microfônicos da Cóclea/efeitos dos fármacos , Citotoxinas/toxicidade , Maleato de Dizocilpina/farmacologia , Cobaias , Microscopia Eletrônica de Varredura , Óxido Nítrico/fisiologia , Óxido Nítrico Sintase , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , ômega-N-Metilarginina
15.
Cancer ; 72(3): 697-706, 1993 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-8392903

RESUMO

BACKGROUND: Until now, no dose-response correlation has been clearly defined in small cell lung cancer (SCLC). METHODS: Forty-one consecutive patients with SCLC entered this study, 21 (limited [L]/extensive [E] = 10/11) patients (group A) received cisplatin 60 mg/m2, etoposide 120 mg/m2 x 3, and escalating epirubicin (5 mg/m2) starting from 45 mg/m2, every 3 weeks for six courses. RESULTS: The maximum tolerated dose (MTD) was reached at epirubicin 60 mg/m2. In 15 (L/E = 9/6) patients (group B), who were submitted to the same combination plus granulocyte-macrophage colony-stimulating factor (GM-CSF) 10 micrograms/kg on days 4 to 14, the MTD was reached at the epirubicin dose of 70 mg/m2. In five (L/E = 4/1) patients (group C) treated as in group B, but with a GM-CSF priming from day -17 to -7 before the first cycle, the MTD was again at 70 mg/m2. Group A patients received 73% of the planned cycles; groups B and C, 86% (P < 0.015). Twenty-five percent of group A cycles versus 6% of groups B and C were delayed (P = 0.0018). The chemotherapy dose was reduced in 15% versus 1.5% of cycles (P = 0.0072). A significant difference was observed in the delivered dose intensity (DI) and in the relative DI with an increase of 29% for cisplatin and etoposide (P < 0.0005; P = 0.0017) and of 63% for epirubicin (P < 0.0000). In group A, the response rate was 72% (24% complete response [CR]), and in groups B and C, 95% (40% CR). Bone marrow myeloid precursor (BMMP) proliferative activity was determined in 21 patients after in vivo bromodeoxyuridine infusion. In GM-CSF-treated patients the production rate evaluated before the starting of the second, fourth, and fifth cycle was significantly higher than the corresponding value of the first cycle. CONCLUSIONS: GM-CSF induces a significant increase of dose intensity by a long-lasting and cumulative enhancement of BMMP proliferation.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Pequenas/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Pequenas/sangue , Contagem de Células/efeitos dos fármacos , Cisplatino/administração & dosagem , Relação Dose-Resposta a Droga , Epirubicina/administração & dosagem , Epirubicina/efeitos adversos , Etoposídeo/administração & dosagem , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/efeitos adversos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
16.
Neuropathol Appl Neurobiol ; 19(4): 324-8, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8232752

RESUMO

Tumour necrosis factor-alpha (TNF alpha) is a major proinflammatory cytokine which appears in the cerebrospinal fluid very early after endotoxin challenge, and is likely to be produced locally. Following in vivo and in vitro challenge with endotoxin, we have demonstrated immunocytochemically and by in situ hybridization that pig and guinea-pig choroid plexus ependymal cells can produce TNF alpha. Immuno-electron microscopy shows that this protein is localized within ependymal cells to the cytoplasm and microvilli. We suggest that this TNF alpha may be important in the initiation of the inflammatory response in bacterial meningitis.


Assuntos
Plexo Corióideo/metabolismo , Epêndima/metabolismo , Fator de Necrose Tumoral alfa/biossíntese , Animais , Encéfalo/citologia , Plexo Corióideo/citologia , Plexo Corióideo/efeitos dos fármacos , Endotoxinas/farmacologia , Epêndima/efeitos dos fármacos , Escherichia coli , Cobaias , Imuno-Histoquímica , Hibridização In Situ , Microscopia Imunoeletrônica , Fator de Necrose Tumoral alfa/líquido cefalorraquidiano
17.
Ann Hematol ; 66(4): 185-93, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8387346

RESUMO

Information on the kinetics of bone marrow (BM) myeloid precursors (BMMP) is required for integrating cancer chemotherapy with granulocyte-macrophage colony-stimulating factor (rhGM-CSF), with the aim of reducing neutropenia. Using bivariate flow-cytometric analysis of the in vivo incorporation of bromode-oxyuridine (BUDR) vs DNA content we have studied the kinetics of BMMP in 21 patients with SCLC during the first of six chemotherapy courses (etoposide, epirubicin, and cis-platinum, days 1-3, every 21 days), given alone (eight patients) or followed by rhGM-CSF (10 micrograms/kg/day s.c., days 4-14) as BM rescue (eight patients) or both preceded (days -17 to -7, as BM priming) and followed by rhGM-CSF (five patients). At 11-14 days after the start of these therapies there was an increase in the baseline proliferative activity of proliferating BMMP and a shortening in the time needed by the metamyelocyte to mature and to leave the marrow. Both effects were greater and were maintained to a significantly greater degree a week later in patients who received chemotherapy plus rhGM-CSF rescue than in those who received chemotherapy alone or rhGM-CSF priming alone. At day 11-14 the pretreatment median cell production rate of pBMMP was increased by 340%, 150%, and 183% and the maturation time was reduced by 80%, 45%, and 57%, respectively, in the three groups. A week later, the corresponding figures were 206%, 111%, and 157% and 50%, 18%, and 45%. Hence, an identical rhGM-CSF schedule is more effective in increasing the neutrophil production by BMMP when given following chemotherapy as BM rescue than before it as BM priming. In both the rescue and the priming schedule, the increase in proliferative activity of BMMP just at the end of rhGM-CSF stimulation was linked to both an increase in the labeling index and a reduction in duration of S-phase (TS), while a week later it was linked solely to reduction in TS. This could actually reduce one of the two kinetic targets of subsequently administered cytostatics, i.e., a high LI and a long time spent in S phase. From this study, accurate kinetic data can be obtained with the in vivo BUDR technique that are useful in scheduling rhGM-CSF.


Assuntos
Medula Óssea/patologia , Carcinoma de Células Pequenas/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Idoso , Carcinoma de Células Pequenas/patologia , Divisão Celular/efeitos dos fármacos , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/administração & dosagem
18.
Acta Otolaryngol ; 113(2): 152-9, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8475728

RESUMO

The cytolytic toxin, pneumolysin, from the gram positive bacterium, Streptococcus pneumoniae, when perfused through the scala tympani of the guinea pig cochlea reduced the amplitude of both the compound action potential and the cochlear microphonic potential. When the surface of the organ of Corti was examined by scanning electron microscopy, both inner and outer hair cells and supporting cells were found to be damaged. Inner hair cells and outer hair cells of row 3 were the most susceptible to damage by pneumolysin, followed by row 2 and then by row 1 of the outer hair cells. Damage to hair cells included disruption and splaying of stereocilia, loss of stereocilia and complete dissolution of hair bundles. Apical surfaces of hair cells and supporting cells were torn, pitted and cratered with shrinkage and tearing of cell boundaries. Within the dose range perfused (0.05-1 micrograms/microliters in a 10 microliters aliquot), the magnitude of the physiological and anatomical lesions was concentration dependent. The cytotoxic effects of pneumolysin reported here may be clinically significant factors in deafness caused by meningitis and otitis media in humans.


Assuntos
Cóclea/microbiologia , Células Ciliadas Auditivas/efeitos dos fármacos , Streptococcus pneumoniae/isolamento & purificação , Estreptolisinas/toxicidade , Animais , Cóclea/citologia , Surdez/etiologia , Feminino , Cobaias , Masculino , Meningite/complicações , Meningite/tratamento farmacológico , Microscopia Eletrônica , Otite Média/complicações , Otite Média/tratamento farmacológico , Estreptolisinas/farmacologia , Estreptolisinas/uso terapêutico
19.
Thyroid ; 3(2): 125-7, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8369651

RESUMO

Tolosa Hunt syndrome (THS) is a painful ophthalmoplegia due to a nonspecific inflammatory process in the cavernous sinus or to parasellar neoplasms. Although the cause of the disease is unknown, previous observations support the hypothesis that THS may be only one manifestation of a generalized vasculitis. The diagnosis is based on findings of painful ophthalmoplegia, excellent response to corticosteroids, and exclusion of other causes including aneurysm, diabetes mellitus, paranasal mucocele, and carotid cavernous fistula. We report the case of a 24-year-old woman with THS who had undergone thyroidectomy 4 years before admission for goiter with histologic diagnosis of Hashimoto's thyroiditis. This case shows the unusual association between Hashimoto's thyroiditis and THS and supports the autoimmune origin of both diseases.


Assuntos
Oftalmoplegia/complicações , Tireoidite Autoimune/complicações , Adulto , Autoimunidade , Feminino , Humanos , Oftalmoplegia/etiologia , Oftalmoplegia/imunologia , Tireoidite Autoimune/etiologia , Tireoidite Autoimune/imunologia
20.
Clin Investig ; 71(8 Suppl): S129-33, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8241696

RESUMO

This multicenter study evaluated the efficacy and tolerability of coenzyme Q10 in 1715 outpatients with chronic heart failure (New York Heart Association classes II and III), stabilized with standard therapy for 3 months. The patients were treated with coenzyme Q10 at a daily dose of 50 mg for 4 weeks, in addition to receiving conventional therapy. The efficacy of coenzyme Q10 was assessed by an open study that evaluated the improvement in clinical signs and symptoms of heart failure. After the baseline evaluation the subjects were seen on days 15 and 30. The intensity of signs and symptoms was assessed by a semiquantitative 4-point scale. Our results demonstrate that the administration of coenzyme Q10 in association with standard therapy improves dyspnea at rest, exertional dyspnea, palpitations, cyanosis, hepatomegaly, pulmonary rales, ankle edema, heart rate, and systolic and diastolic blood pressure in patients with stabilized heart failure. The rate of improvement and the low number of side effects in this large group of patients demonstrate that despite some methodological limitations in the study design and the short period of treatment (4 weeks) coenzyme Q10 given at a daily dose of 50 mg led to an improvement in the signs and symptoms of heart failure and in the quality of life.


Assuntos
Ubiquinona/análogos & derivados , Idoso , Quimioterapia Adjuvante , Coenzimas , Feminino , Humanos , Itália , Masculino , Qualidade de Vida , Ubiquinona/efeitos adversos , Ubiquinona/uso terapêutico
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