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1.
Clin Oncol (R Coll Radiol) ; 35(8): 524-532, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37357120

RESUMEN

Radiation plays an important role in organ preservation for gastrointestinal malignancies, with a watch and wait strategy enabling surgery to be avoided in patients who are not suitable or who are refusing surgery. Brachytherapy boost allows the radiation dose to be escalated, which plays a pivotal role in the successful outcome of achieving organ preservation. Here we describe the role of brachytherapy in two common gastrointestinal malignancies (oesophagus and rectum). Their indications and how the brachytherapy procedures are carried out, together with the dose and fractionation commonly used are discussed. The use of brachytherapy needs to be included in the training curriculum at all academic centres so that its use is developed by the newer generation of radiation oncologists. Its current non-use due to bias, lack of training and availability is no longer justified, given the overwhelming published evidence for the role of brachytherapy to improve organ preservation for both radical treatment and palliation in gastrointestinal malignancies.


Asunto(s)
Braquiterapia , Neoplasias Gastrointestinales , Neoplasias del Recto , Humanos , Neoplasias del Recto/tratamiento farmacológico , Recto , Terapia Neoadyuvante , Quimioradioterapia , Braquiterapia/métodos , Neoplasias Gastrointestinales/radioterapia
2.
Brachytherapy ; 16(3): 630-638, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28202343

RESUMEN

PURPOSE: Endobronchial metastasis (EBM) originating from primary cancers outside the lung is rare. External beam radiotherapy is often attempted for control of symptoms with variable effectiveness and retreatment is challenging if symptoms recur. There is limited documentation of high-dose-rate brachytherapy for EBM in the literature. METHODS AND MATERIALS: A prospective database was created from 2006 to 2015. Patients with EBM who received high-dose-rate brachytherapy were included. Cough, dyspnea, chest pain, and hemoptysis were assessed and graded (0-4) at the time of initial consult and in followup. Symptom-free survival and re-expansion were assessed. RESULTS: Thirty-five patients with EBM were identified. Most patients received three fractions of 700 cGy, and 17 patients had prior external beam radiotherapy. Median symptom-free and overall survival were 67 and 117 days. After brachytherapy, improvement in cough was documented in 75.0%, hemoptysis in 76.4%, dyspnea in 60.0% for a median of 3-6 months. Of the 22 patients who had subsequent chest imaging, re-expansion was documented in 32%. There were no significant toxicities reported. CONCLUSIONS: Brachytherapy appears effective in achieving durable symptom control of cough hemoptysis, and dyspnea in patients with EBM and should be considered routinely for palliation where available. Further studies are required to better characterize expected symptom improvement, lung re-expansion rates, and efficacy in comparison with other local treatments.


Asunto(s)
Braquiterapia/métodos , Neoplasias de los Bronquios/complicaciones , Neoplasias de los Bronquios/radioterapia , Cuidados Paliativos/métodos , Neoplasias de los Bronquios/secundario , Dolor en el Pecho/etiología , Tos/etiología , Supervivencia sin Enfermedad , Fraccionamiento de la Dosis de Radiación , Disnea/etiología , Femenino , Hemoptisis/etiología , Humanos , Masculino , Estudios Prospectivos , Tasa de Supervivencia , Evaluación de Síntomas , Resultado del Tratamiento
3.
Environ Res ; 147: 565-71, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26750714

RESUMEN

The relevance of radiation-induced bystander effects in humans is unclear. Much of the existing data relate to cell lines but the effect of bystander signals in complex human tissues is unclear. A phase II clinical study was untaken, where blood sera from 60 patients along with 15 cancer-free volunteers were used to detect whether measurable bystander factor(s) could be found in the blood following high dose rate (HDR) brachytherapy. Overall, there was no significant change in bystander signal production (measured in a human keratinocyte reporter system) before and after one treatment fraction of HDR brachytherapy (p>0.05). Further assessment of patient characteristics and environmental modifiable factors including smoking were also analyzed. Similar to previously published data, samples taken from smokers produced weaker signals compared to non-smokers (p<0.05). Although the number of non-smoking subjects was low, there was a clear decrease in cloning efficiency observed in keratinocyte cultures for these patients that requires further study. This study found that samples taken from smokers do not produce bystander signals, whereas samples taken from non-smokers can produce such signals following HDR brachytherapy. These findings highlight the importance of studying the interactions of multiple stressors including environmental modifiers with radiation, since some factors such as smoking may elicit protection in tumor cells which could counteract the effectiveness of radiation therapy.


Asunto(s)
Adenocarcinoma/radioterapia , Braquiterapia , Efecto Espectador , Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/radioterapia , Fumar , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Carcinoma de Células Escamosas de Esófago , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores Sexuales
4.
Med Phys ; 40(2): 021913, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23387761

RESUMEN

PURPOSE: A 2D∕3D registration algorithm is proposed for registering orthogonal x-ray images with a diagnostic CT volume for high dose rate (HDR) lung brachytherapy. METHODS: The algorithm utilizes a rigid registration model based on a pixel∕voxel intensity matching approach. To achieve accurate registration, a robust similarity measure combining normalized mutual information, image gradient, and intensity difference was developed. The algorithm was validated using a simple body and anthropomorphic phantoms. Transfer catheters were placed inside the phantoms to simulate the unique image features observed during treatment. The algorithm sensitivity to various degrees of initial misregistration and to the presence of foreign objects, such as ECG leads, was evaluated. RESULTS: The mean registration error was 2.2 and 1.9 mm for the simple body and anthropomorphic phantoms, respectively. The error was comparable to the interoperator catheter digitization error of 1.6 mm. Preliminary analysis of data acquired from four patients indicated a mean registration error of 4.2 mm. CONCLUSIONS: Results obtained using the proposed algorithm are clinically acceptable especially considering the complications normally encountered when imaging during lung HDR brachytherapy.


Asunto(s)
Algoritmos , Braquiterapia/métodos , Imagenología Tridimensional/métodos , Neoplasias Pulmonares/radioterapia , Radioterapia Guiada por Imagen/métodos , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Fantasmas de Imagen , Dosificación Radioterapéutica , Factores de Tiempo , Tomografía Computarizada por Rayos X
5.
Inflammopharmacology ; 17(1): 42-9, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19112586

RESUMEN

Extracts of Tanacetum parthenium (L.) Sch. Bip., a plant known under the common name "Feverfew", contains the sesquiterpene lactone parthenolide, a potent skin sensitizer. To eliminate the risk of skin sensitization from Feverfew, we developed a parthenolide-depleted extract of Feverfew (PD-Feverfew) and determined its effectiveness as an anti-inflammatory agent. We confirmed that PD-Feverfew was sufficiently depleted of parthenolide since PD-Feverfew did not inhibit TNF-alpha induced-NF-kappaB activity unlike parthenolide containing whole Feverfew. PD-Feverfew directly inhibited the activity of pro-inflammatory enzymes 5-lipoxygenase, phosphodiesterase-3 and phosphodiesterase-4. PD-Feverfew inhibited the release of pro-inflammatory mediators nitric oxide, PGE(2) and TNF-alpha from macrophages and TNF-alpha, IL-2, IFN-gamma and IL-4 from human peripheral blood mononuclear cells. Additionally, PD-Feverfew inhibited TPA-induced release of PGE(2) from human skin equivalents. In vivo, PD-Feverfew inhibited oxazolone-induced dermatitis, and was more potent than whole Feverfew in reducing TPA-induced dermatitis. Finally the efficacy of PD-Feverfew was confirmed clinically by a reduction in erythema in a methyl nicotinate-induced vasodilation model. In conclusion, our results indicate that PD-Feverfew extracts have potent anti-inflammatory activity suggesting that this botanical would be efficacious in relieving inflammation without inducing immune sensitization.


Asunto(s)
Antiinflamatorios/farmacología , Inflamación/tratamiento farmacológico , Extractos Vegetales/farmacología , Tanacetum parthenium/química , Adulto , Animales , Antiinflamatorios/aislamiento & purificación , Células Cultivadas , Dermatitis/tratamiento farmacológico , Dermatitis/fisiopatología , Eritema/tratamiento farmacológico , Eritema/fisiopatología , Femenino , Humanos , Inflamación/fisiopatología , Mediadores de Inflamación/metabolismo , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Leucocitos Mononucleares/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Masculino , Ratones , Persona de Mediana Edad , Sesquiterpenos/aislamiento & purificación , Sesquiterpenos/toxicidad , Adulto Joven
6.
Infect Agent Cancer ; 1: 2, 2006 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-17150131

RESUMEN

BACKGROUND: Infections with certain human herpesviruses have been established as risk factors for some cancer types. For example, Epstein-Barr Virus is considered a cause of Burkitt's lymphoma and other immunosuppression related lymphomas, Hodgkin lymphoma, and nasopharyngeal cancer. Several other human herpesviruses have been linked to cancers but the totality of evidence is inconclusive. METHODS: We conducted a systematic sub-study from within an ongoing case control study of adult black South Africans to investigate the relationship between antibodies to six human herpesviruses and seven cancer groups that may be caused by infectious agents. Subjects had incident cancers of the oral cavity (n = 88), the cervix (n = 53), the prostate (n = 66), Hodgkin lymphoma (n = 83), non-Hodgkin lymphoma (n = 80), multiple myeloma (n = 94) or leukaemia (n = 203). For comparison, patients with other cancers (n = 95) or cardiovascular disease (n = 101) were randomly selected from within the study. Patients were interviewed and their blood was tested for IgG antibodies against HSV-1, HSV-2, VZV, EBV-EBNA, CMV and HHV-6 using enzyme linked immunosorbent assays. Because these viruses are highly prevalent in this population, optical density results from the assays were used as an indirect, quantitative measure of antibody level. RESULTS: There was significant variation in the mean log antibody measures for HSV-2, VZV, CMV and HHV-6 between the disease groups. However, none of the specific cancer groups had significantly higher mean log antibody measures for any of the viruses compared to either control group. In a more detailed examination of seven associations between cancers and herpesviruses for which there had been prior reports, two statistically significant associations were found: a decreasing risk of myeloid leukaemia and an increasing risk of oral cancer with increasing tertiles of antibodies against HHV-6 compared to all other patients (p-trend = 0.03 and 0.02, respectively). Odds ratios for the top tertile compared to the bottom tertile were 0.58 (95%CI 0.3-1.0) for myeloid leukaemia and 2.21 (95% CI 1.1-4.3) for oral cancer. CONCLUSION: In this population, using these tests for IgG, neither mean antibody measure nor high antibody measure against human herpesviruses 1-6 was strongly associated with any of the seven cancer groups. However, we may not have had sufficient power to detect weak associations or associations with a sub-type of cancer if they were present.

7.
Artículo en Inglés | MEDLINE | ID: mdl-15203026

RESUMEN

An analytical method for the simultaneous quantitation of arseneous acid (As(III)), arsenic acid (As(V)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and trimethylarsine oxide (TMAO) in human urine by coupling of high-performance liquid chromatography with hydride generation atomic absorption spectrometry (HPLC/HG-AAS) via a flow-injection interface is presented. After arsenic species separation by anion-exchange displacement chromatography the compounds are on-line reduced to their corresponding hydrides and detected by atomic absorption spectrometry. Detection limits range from 1.1 (TMAO) to 2.6 microg/L (As(V)). The method has been applied to determine arsenic species in the urine of a volunteer before and after consumption of seafood as well as to analyse certified reference urine samples for their arsenic species content.


Asunto(s)
Arsenicales/orina , Cromatografía Líquida de Alta Presión/métodos , Espectrofotometría Atómica/métodos , Calibración , Humanos , Control de Calidad , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
8.
Prostate Cancer Prostatic Dis ; 7(2): 126-31, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15111980

RESUMEN

In a prospective randomized study, we compare standard prostate biopsy to extensive biopsy utilizing intravenous conscious sedation (IVCS). Initial biopsy patients (n=197) were randomized to either standard biopsy using intrarectal lidocaine gel (6-12 biopsies, mean 10.1) or extensive biopsy (24 biopsies) using IVCS. Cancer detection and urinary symptoms were no different between groups. However, biopsy pain was rated significantly lower and satisfaction significantly higher in the extensive biopsy group. Temporary urinary retention occurred in 4% of the extensive biopsy group. Extended biopsy with 24 samples does not improve cancer detection compared to standard biopsy when 10 cores are obtained. Extensive biopsy is very well tolerated and associated with less pain and more satisfaction than standard biopsy.


Asunto(s)
Biopsia/efectos adversos , Biopsia/métodos , Dolor/etiología , Neoplasias de la Próstata/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Anestésicos Intravenosos/administración & dosificación , Sedación Consciente , Fentanilo/administración & dosificación , Humanos , Masculino , Midazolam/administración & dosificación , Persona de Mediana Edad , Morbilidad , Estudios Prospectivos , Neoplasias de la Próstata/patología
9.
Epidemiol Infect ; 132(6): 1191-7, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15635980

RESUMEN

Between January 1994 and October 1997, we interviewed 2576 black in-patients with newly diagnosed cancer in Johannesburg and Soweto, South Africa. Blood was tested for HIV-1 and HHV-8 antibodies and the study was restricted to 2191 HIV-1 antibody-negative patients. We examined the relationship between infection with HHV-8 and sociodemographic and behavioural factors using unconditional logistic regression models. Of the 2191 HIV-1 negative patients who did not have Kaposi's sarcoma, 854 (39.1%) were positive for antibodies against the latent nuclear antigen of HHV-8 encoded by orf73 in a immunofluorescence assay. Infection with HHV-8 was independently associated with increasing age (P trend = 0.02). For females, independent risk factors also included working in a paid domestic capacity (OR 1.63, 95% CI 1.09-2.44, P = 0.02), defining occupational status as economically non-active unemployed (OR 1.70, 95% CI 1.06-2.72, P = 0.03), having a state pension or being on a disability grant (OR 1.49, 95% CI 1.05-2.11, P = 0.02), using oral contraceptives (OR 1.43, 95% CI 1.03-1.99, P = 0.03) and having a delayed age at menarche (P trend = 0.04). The relationship between these variables and HHV-8 antibody status requires further, prospective study.


Asunto(s)
Infecciones por VIH/complicaciones , Infecciones por Herpesviridae/etiología , Infecciones por Herpesviridae/transmisión , Herpesvirus Humano 8/patogenicidad , Clase Social , Adulto , Anciano , Estudios Transversales , Femenino , Técnica del Anticuerpo Fluorescente , VIH-1/patogenicidad , Humanos , Huésped Inmunocomprometido , Incidencia , Masculino , Persona de Mediana Edad , Neoplasias/complicaciones , Neoplasias/virología , Factores de Riesgo , Sudáfrica/epidemiología
10.
Br J Cancer ; 86(11): 1751-6, 2002 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-12087462

RESUMEN

The authors used data collected from 1995 to 1999, from an on-going cancer case-control study in greater Johannesburg, to estimate the importance of tobacco and alcohol consumption and other suspected risk factors with respect to cancer of the oesophagus (267 men and 138 women), lung (105 men and 41 women), oral cavity (87 men and 37 women), and larynx (51 men). Cancers not associated with tobacco or alcohol consumption were used as controls (804 men and 1370 women). Tobacco smoking was found to be the major risk factor for all of these cancers with odds ratios ranging from 2.6 (95% CI 1.5-4.5) for oesophageal cancer in female ex-smokers to 50.9 (95% CI 12.6-204.6) for lung cancer in women, and 23.9 (95% CI 9.5-60.3) for lung cancer and 23.6 (95% CI 4.6-121.2) for laryngeal cancer in men who smoked 15 or more grams of tobacco a day. This is the first time an association between smoking and oral and laryngeal cancers has been shown in sub-Saharan Africa. Long-term residence in the Transkei region in the southeast of the country continues to be a risk factor for oesophageal cancer, especially in women (odds ratio=14.7, 95% CI 4.7-46.0), possibly due to nutritional factors. There was a slight increase in lung cancer (odds ratio=2.9, 95% CI 1.1-7.5) in men working in 'potentially noxious' industries. 'Frequent' alcohol consumption, on its own, caused a marginally elevated risk for oesophageal cancer (odds ratio=1.7, 95% CI 1.0-2.9, for women and odds ratio=1.8, 95% CI 1.2-2.8, for men). The risks for oesophageal cancer in relation to alcohol consumption increased significantly in male and female smokers (odds ratio=4.7, 95% CI=2.8-7.9 in males and odds ratio=4.8, 95% CI 3.2-6.1 in females). The above results are broadly in line with international findings.


Asunto(s)
Población Negra , Neoplasias Laríngeas/epidemiología , Neoplasias Pulmonares/epidemiología , Neoplasias de la Boca/epidemiología , Adolescente , Adulto , Anciano , Consumo de Bebidas Alcohólicas/efectos adversos , Estudios de Casos y Controles , Escolaridad , Femenino , Geografía , Humanos , Neoplasias Laríngeas/etiología , Estilo de Vida , Neoplasias Pulmonares/etiología , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/etiología , Factores de Riesgo , Caracteres Sexuales , Fumar/efectos adversos , Sudáfrica/epidemiología , Encuestas y Cuestionarios
11.
J Urol ; 166(3): 866-70, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11490235

RESUMEN

PURPOSE: Isolated high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation on prostate biopsy increases the risk of identifying cancer on repeat biopsy. We report the results of repeat prostate biopsy for high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation, and propose an optimal repeat biopsy strategy. MATERIALS AND METHODS: Of 1,391 men who underwent standard systematic sextant biopsy of the prostate 137 (9.8%) had isolated high grade prostatic intraepithelial neoplasia or atypical small acinar proliferation, including 100 who underwent repeat prostate biopsy within 12 months of the initial biopsy. RESULTS: Adenocarcinoma was detected in 47 of the 100 patients who underwent repeat biopsy. The initial biopsy site of high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation matched the sextant location of cancer on repeat biopsy in 22 cases (47%). Repeat biopsy directed only to the high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation site on initial biopsy would have missed 53% of cancer cases. In 12 of the 47 men (26%) cancer was limited to the side of the prostate contralateral to the side of high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation. Of the 31 patients with cancer in whom the transition zone was sampled cancer was limited to the transition zone in 4 (13%) and evident at other biopsy sites in 13 (42%). The only significant predictor of positive repeat biopsy was mean prostate specific antigen velocity plus or minus standard error (1.37 +/- 1.4 versus 0.52 +/- 0.8 ng./ml. per year, p <0.001). CONCLUSIONS: Patients with isolated high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation on prostate biopsy are at 47% risk for cancer on repeat biopsy. The optimal repeat biopsy strategy in this setting should include bilateral biopsies of the standard sextant locations. We also strongly recommend that transition zone sampling should be considered.


Asunto(s)
Adenocarcinoma/patología , Biopsia con Aguja/estadística & datos numéricos , Carcinoma de Células Acinares/patología , Neoplasia Intraepitelial Prostática/patología , Neoplasias de la Próstata/patología , Adenocarcinoma/epidemiología , Carcinoma de Células Acinares/epidemiología , Humanos , Masculino , Neoplasia Intraepitelial Prostática/epidemiología , Neoplasias de la Próstata/epidemiología
12.
Eur J Biochem ; 268(8): 2344-50, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11298753

RESUMEN

RNA polymerase is known to bind and utilize the overlapping promoters P1 and P2 in Escherichia coli galactose operon. We have identified an additional specific site upstream of P2, where RNA polymerase binds in a heparin-resistant manner. Binding of polymerase to this site, termed P3, occurs simultaneous to its binding at P1/P2. We have located this P3 site by DNase I footprinting. A 63 base pair region centered around position - 100 with respect to galP1 is protected by polymerase. Interestingly, a Pribnow box TATAAT is present within this protected region (-103 to -108). We have shown that transcription occurs from P3 in vitro. Primer extension analysis provides direct evidence that P3 is transcribed in vivo. The start site of transcription has been mapped at -96 position relative to galP1. beta-galactosidase assays with different gal promoter constructs reveal that while P3 alone functions as a weak in vivo promoter, it has a synergistic effect on transcription from the gal operon, since deletion of P3 or specifically mutating its -10 region result in a substantial reduction in the gal promoter activity.


Asunto(s)
ARN Polimerasas Dirigidas por ADN/metabolismo , Galactosa/metabolismo , Sitios de Unión , Huella de ADN , Desoxirribonucleasa I/metabolismo , Relación Dosis-Respuesta a Droga , Electroforesis en Gel de Poliacrilamida , Escherichia coli/metabolismo , Modelos Genéticos , Mutación , Operón , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Unión Proteica , Transcripción Genética , beta-Galactosidasa/metabolismo
13.
Int J Cancer ; 88(3): 489-92, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11054682

RESUMEN

Despite the high prevalence of infection by the Human Immunodeficiency Virus (HIV) in South Africa, information on its association with cancer is sparse. Our study was carried out to examine the relationship between HIV and a number of cancer types or sites that are common in South Africa. A total of 4,883 subjects, presenting with a cancer or cardiovascular disease at the 3 tertiary referral hospitals in Johannesburg, were interviewed and had blood tested for HIV. Odds ratios associated with HIV infection were calculated by using unconditional logistic regression models for 16 major cancer types where data was available for 50 or more patients. In the comparison group, the prevalence of HIV infection was 8.3% in males and 9.1% in females. Significant excess risks associated with HIV infection were found for Kaposi's sarcoma (OR=21.9, 95% CI=12.5-38.6), non-Hodgkin lymphoma (OR=5.0, 95%CI=2.7-9.5), vulval cancer (OR=4.8, 95%CI= 1.9-12.2) and cervical cancer (OR= 1.6, 95%CI= 1.1-2.3) but not for any of the other major cancer types examined, including Hodgkin disease, multiple myeloma and lung cancer. In Johannesburg, South Africa, HIV infection was associated with significantly increased risks of Kaposi's sarcoma, non-Hodgkin lymphoma and cancers of the cervix and the vulva. The relative risks for Kaposi's sarcoma and non-Hodgkin lymphoma associated with HIV infection were substantially lower than those found in the West.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/complicaciones , VIH-1 , Neoplasias/epidemiología , Adolescente , Adulto , Anciano , Femenino , Humanos , Linfoma Relacionado con SIDA/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Sarcoma de Kaposi/epidemiología , Sudáfrica/epidemiología , Neoplasias del Cuello Uterino/epidemiología
14.
Urology ; 55(6): 950, 2000 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-10840123

RESUMEN

We report the first case of priapism associated with the use of sildenafil citrate. The patient was a 28-year-old man with mild erectile dysfunction after penile trauma who self-treated with a 100-mg dose of sildenafil citrate, resulting in low-flow priapism. After aspiration and intracorporal injection of alpha-agonists, the priapism resolved. The patient's erectile function returned to his prepriapism baseline.


Asunto(s)
Inhibidores de Fosfodiesterasa/efectos adversos , Piperazinas/efectos adversos , Priapismo/inducido químicamente , 3',5'-GMP Cíclico Fosfodiesterasas/antagonistas & inhibidores , Adulto , Disfunción Eréctil/tratamiento farmacológico , Disfunción Eréctil/etiología , Humanos , Masculino , Pene/lesiones , Purinas , Citrato de Sildenafil , Sulfonas
15.
S Afr J Surg ; 38(1): 13-6, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-12365113

RESUMEN

Files of 8 patients with primary angiosarcomas treated in the Department of Radiation Oncology at the University of the Witwatersrand from 1982 to 1995 were identified. None of these patients had received prior radiotherapy or chemotherapy which would have predisposed them to the formation of an angiosarcoma. Slides of 6 patients were reviewed. Five of the 6 were confirmed as having angiosarcomas, while 1 patient was found to have a peripheral neuro-epithelial tumour. Four patients had angiosarcomas of the breast, while there was 1 patient each with angiosarcoma of the skin, intestine and brain. Complete excision was the primary modality of management whenever possible. Postoperative radiotherapy was given in cases of incomplete excision, patient refusal of radical surgery or gross tumour. Four patients died within 4 months of diagnosis. Three patients are alive (2 with no evidence of disease) 22-96 months after diagnosis. In 1 patient follow-up details were not available as he did not return for treatment. Angiosarcomas are aggressive malignant tumours arising from the endothelial cells. Complete surgical excision is the treatment of choice in the management of this aggressive disease, which has a poor prognosis.


Asunto(s)
Neoplasias Abdominales/patología , Neoplasias Abdominales/cirugía , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Hemangiosarcoma/patología , Hemangiosarcoma/cirugía , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/cirugía , Neoplasias Abdominales/mortalidad , Adolescente , Adulto , Antineoplásicos/uso terapéutico , Biopsia , Neoplasias Encefálicas/mortalidad , Neoplasias de la Mama/mortalidad , Causalidad , Quimioterapia Adyuvante , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Hemangiosarcoma/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Radioterapia Adyuvante , Neoplasias Cutáneas/mortalidad , Sudáfrica/epidemiología , Análisis de Supervivencia , Resultado del Tratamiento
16.
FEBS Lett ; 453(1-2): 215-8, 1999 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-10403406

RESUMEN

The cyclic AMP receptor protein activates transcription in Escherichia coli, only when complexed with cyclic AMP. The cyclic AMP receptor protein-cyclic AMP complex formed at low concentrations of cyclic AMP has a different conformation from either cyclic AMP receptor protein alone or its complex with cyclic AMP formed at high cyclic AMP concentrations. Various biophysical data suggest that the latter complex resembles free cyclic AMP receptor protein. We have examined the conformational and biological properties of cyclic AMP receptor protein as a function of cyclic AMP concentrations, using the gal operon of E. coli. A biphasic behavior is observed. It is shown that only the complex formed at lower concentrations of cyclic AMP is the transcriptionally active form. This difference between the complexes at different levels of cyclic AMP arises from a decreased ability of the cyclic AMP receptor protein-cyclic AMP complex at high cyclic AMP concentrations to bind to DNA at specific sites.


Asunto(s)
Proteína Receptora de AMP Cíclico/metabolismo , AMP Cíclico/farmacología , Proteínas de Unión al ADN/metabolismo , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Proteínas Portadoras , Proteína Receptora de AMP Cíclico/química , Proteínas de Unión al ADN/química , Galactosa/metabolismo , Operón , Unión Proteica , Conformación Proteica , Transcripción Genética
17.
Int J Radiat Oncol Biol Phys ; 40(2): 447-53, 1998 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-9457834

RESUMEN

PURPOSE: To optimize the dose of fractionated brachytherapy for palliation of advanced esophageal cancer. METHODS AND MATERIALS: One hundred and seventy-two patients with advanced esophageal cancer were randomized to receive 12 Gy/2 fractions (group A); 16 Gy/2 fractions (group B), and 18 Gy/3 fractions (group C) by high dose rate intraluminal brachytherapy (HDRILBT). Treatment was given weekly and dose prescribed at 1 cm from the source axis. Patients were followed up monthly and assessed for dysphagia relief and development of complications. RESULTS: Twenty-two patients died before completing treatment due to advanced disease and poor general condition. The overall survival was 19.4% at the end of 12 months for the whole group (A--9.8%, B--22.46%, C--35.32%; p > 0.05). The dysphagia-free survival was 28.9% at 12 months for the whole group (A--10.8%, B--25.43%, C--38.95%; p > 0.05). Forty-three patients developed fibrotic strictures needing dilatation (A--5 of 35, B--15 of 60, C--23 of 55; p = 0.032). Twenty-seven patients had persistent luminal disease (A--11, B--6, C--10), 15 of which progressed to fistulae (A--7, B--2, C--6; p = 0.032). There was no effect of age, sex, race, histology, performance status, previous dilation, presenting dysphagia score, presenting weight, grade, tumor length, and stage on overall survival, dysphagia-free, and complication-free survival (p > 0.05). On a multivariate analysis, brachytherapy dose (p = 0.002) and tumor length (p = 0.0209) were found to have a significant effect on overall survival; brachytherapy dose was the only factor that had an impact on local tumor control (p = 0.0005), while tumor length was the only factor that had an effect on dysphagia-free survival (p = 0.0475). When compared to other forms of palliation currently available (bypass surgery, laser, chemotherapy, intubation, external radiotherapy), fractionated brachytherapy gave the best results with a median survival of 6.2 months. CONCLUSIONS: Fractionated brachytherapy is the best modality for palliation of advanced esophageal cancer. It offers the best palliation to patient when compared to all other modalities currently available. The optimal brachytherapy dose ranges between 16 Gy in two fractions and 18 Gy in three fractions given a week apart.


Asunto(s)
Braquiterapia/métodos , Neoplasias Esofágicas/radioterapia , Cuidados Paliativos/métodos , Braquiterapia/efectos adversos , Trastornos de Deglución/etiología , Supervivencia sin Enfermedad , Fraccionamiento de la Dosis de Radiación , Neoplasias Esofágicas/mortalidad , Neoplasias Esofágicas/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Prospectivos , Insuficiencia del Tratamiento
18.
Laryngoscope ; 107(9): 1276-80, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9292617

RESUMEN

A retrospective analysis was performed of 50 patients with adenoid cystic carcinoma who were seen in the Department of Radiation Oncology, University of Witwatersrand, Johannesburg, South Africa, in the past 10 years. There were 25 men and 25 women with a mean age of 52 years (age range, 21 to 88 years). Five patients had metastatic disease, and 17 had neural invasion. Thirty-four patients had surgery (11, complete; 23, microscopic residual). Sixteen patients had radiotherapy as initial management. The disease-free survival was 26%, overall survival was 29%, and local control was 30% at 10 years. Most recurrences occurred in the first 3 years. Nine patients had metastasis following treatment. The mean survival after metastasis was 15 months. Seven prognostic variables were analyzed using the log-rank test. There was no impact of age, site, type of salivary gland (major vs. minor), tumor stage, node positivity, or neural invasion on disease-free survival, overall survival, or local control. Extent of surgical resection (complete vs. microscopic residual) had a significant impact on disease-free survival and local control (P < 0.05) but no impact on overall survival (P > 0.05) because of the slow-growing nature of these tumors. Similarly, patients who had microscopic residual after surgery and were treated with radiotherapy did better than those who had biopsy and radiotherapy, although this was not significant statistically (P > 0.05). Thus, whenever possible, every attempt must be made to remove all microscopic tumor by surgery. Addition of postoperative radiotherapy with high-energy photons did not improve the locoregional control or survival in our series. There is a place for neutrons in the treatment of adenoid cystic carcinomas in advanced cases of inoperable or recurrent tumors, as a review of literature shows.


Asunto(s)
Carcinoma Adenoide Quístico/terapia , Neoplasias de las Glándulas Salivales/terapia , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Biopsia , Carcinoma Adenoide Quístico/radioterapia , Carcinoma Adenoide Quístico/secundario , Carcinoma Adenoide Quístico/cirugía , Supervivencia sin Enfermedad , Femenino , Humanos , Modelos Lineales , Metástasis Linfática , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Neoplasia Residual/patología , Neutrones/uso terapéutico , Fotones/uso terapéutico , Pronóstico , Radioterapia Adyuvante , Estudios Retrospectivos , Neoplasias de las Glándulas Salivales/radioterapia , Neoplasias de las Glándulas Salivales/cirugía , Glándulas Salivales/patología , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
19.
Indian J Gastroenterol ; 16(3): 88-90, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9248177

RESUMEN

OBJECTIVE: To analyze retrospectively the disease spectrum and outcome of primary gastrointestinal lymphoma (PGIL) in a tertiary referral center in north India. MATERIAL: Seventy five patients presenting with PGIL between January 1971 and December 1985 were evaluated. RESULTS: The 49 males and 26 females were aged 3.5-69 years (mean 34) at presentation. Abdominal pain, weight loss and vomiting were cardinal symptoms at presentation; the stomach was the most common site of involvement. Histologically, a majority of patients were classified as having diffuse poorly-differentiated lymphocytic lymphoma (46.7%) and diffuse histiocytic type (30.7%). Twenty seven (36%) patients had stage I disease, 31 (40%) stage II, 11 (14.7%) stage III, and 6 (8%) stage IV. At laparotomy, primary resection and anastomosis was carried out in 66 patients, while only biopsies were taken in nine. Forty eight patients received adjuvant radiation with or without chemotherapy. The mean follow-up was 3.9 years (range 1-14). The 5-year actuarial survival was 34%, 25% and 16% for stages I, II, and higher-stage disease, respectively. The survival was significantly better (p < 0.01) for gastric location (44%) compared to other sites (24%). CONCLUSION: PGIL was more common in the 3rd and 4th decades of life, with the stomach being the predominant site of involvement. Survival was better among patients with stages I and II disease, and gastric location of lesion.


Asunto(s)
Neoplasias Gastrointestinales , Linfoma , Adolescente , Adulto , Anciano , Biopsia , Niño , Preescolar , Terapia Combinada , Femenino , Estudios de Seguimiento , Neoplasias Gastrointestinales/epidemiología , Neoplasias Gastrointestinales/patología , Neoplasias Gastrointestinales/terapia , Humanos , India/epidemiología , Linfoma/epidemiología , Linfoma/patología , Linfoma/terapia , Masculino , Persona de Mediana Edad , Morbilidad , Estadificación de Neoplasias , Estudios Retrospectivos , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
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