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1.
Zhonghua Jie He He Hu Xi Za Zhi ; 47(5): 455-459, 2024 May 12.
Artigo em Zh | MEDLINE | ID: mdl-38706068

RESUMO

Here we reported a case of a 52-year-old male with a 13-year history of Crohn's disease who developed disseminated tuberculosis after 2 injections of infliximab. The patient was admitted with a chief complaint of fever with headache of 1 month's duration. Mycobacterium tuberculosis DNA was found positive in cerebrospinal fluid and lavage fluid by lumbar puncture and bronchoscopy. He was diagnosed with tuberculous meningitis, pulmonary tuberculosis, tracheobronchial tuberculosis and lymph node tuberculosis. After treatment with anti-tuberculosis and glucocorticoids, the symptoms did not improve, the lesions progressed, and granulomas were formed in the tracheobronchial lumen. These were considered to be contradictory reactions and thalidomide was given together with glucocorticoids. The patient's clinical condition has improved significantly. Treatment was successfully completed after 18 months with 1 HREZLfxLzd/8 HEZCsLzd/1 HEZCs/8 HZCs.


Assuntos
Talidomida , Humanos , Masculino , Pessoa de Meia-Idade , Talidomida/efeitos adversos , Talidomida/uso terapêutico , Doença de Crohn/tratamento farmacológico , Tuberculose/tratamento farmacológico
2.
Zhonghua Wai Ke Za Zhi ; 54(11): 819-822, 2016 Nov 01.
Artigo em Zh | MEDLINE | ID: mdl-27806773

RESUMO

Trans-oral laporascopic thyroidectomy is a innovative technique that incoporated the concept of natural orifice transluminal endoscopic surgery. Compare to other endoscopic thyroidectomy, trans-oral laporascopic thyroidectomy is characterised with no scar in the body surface, better cosmetic results and conforms to the concept of minimally invasive surgery. At present, trans-oral laporascopic thyroidectomy is still in the initial stages of clinical application and gains a great deal of attention from surgeons all over the world. It mainly includes oral bottom approach and oral vestibular approach. Proponents and researchers in this field have been attempting to use this technique for treatment of thyroid cancer and combine it with the robotics assisted surgical system. In the future, the indications and contraindications of trans-oral laporascopic thyroidectomy need to be further studied and evaluated. Complications and surgical procedures still have many issues need to be solved.


Assuntos
Cirurgia Endoscópica por Orifício Natural , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/métodos , Cicatriz , Endoscopia , Feminino , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Boca , Procedimentos Cirúrgicos Robóticos
3.
Artigo em Zh | MEDLINE | ID: mdl-34344103

RESUMO

Objective: To investigate the feasibility of endoscopic lateral neck dissection via the breast and transoral approaches (ELNDBTOA) for papillary thyroid carcinoma (PTC). Methods: From February 2015 to April 2019, 10 patients with PTC (cN1b) including 1 male and 9 females aged from 22 to 53 years old received ELNDBTOA in the General Surgery Department of Zhongshan Hospital, Xiamen University. Total thyroidectomy, the central lymph node dissection and the selective neck dissection (levels Ⅱ, Ⅲ and Ⅳ) were performed endoscopically via the breast approach, and then the residual lymph nodes were dissected via transoral approach. The medical records, operation time, blood loss, complications and postoperative follow-up outcomes were analyzed retrospectively. SPSS 22.0 software package was used for statistical processing of clinical data of patients. Results: All cases were successfully treated with ELNDBTOA without transfer to open surgery. The average operative time was (362.5±79.7) min, the blood loss was (23.0±14.9) ml, and the postoperative hospital stay was (5.1±1.3) days. The mean number of harvested cervical lymph nodes were (34.2±25.8), and the mean number of positive lymph nodes were (6.5±4.9). Lymph nodes were dissected by the further dissection via oral approach in 6 patients and a total of 9 lateral lymph nodes were havested from 2 of the 6 patients, with 3 positive lymph nodes. Two patients had transient skin numbness in the mandibular area and recovered within two weeks. One patient developed transient hypoparathyroidism and recovered within two months. No secondary bleeding, recurrent laryngeal nerve paralysis, chylous leakage, neck infection, permanent hypoparathyroidism or other complications were observed. The follow-up time was from 16 to 66 months with a median of 42.5 months, no tumor recurrence or metastasis occurred, and also no obvious deformity, abnormal sensation or movement in the chest, neck and mouth was observed. Conclusions: ELNBTOA is safe and feasible, with good cosmetic outcome.


Assuntos
Esvaziamento Cervical , Neoplasias da Glândula Tireoide , Adulto , Feminino , Humanos , Linfonodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Câncer Papilífero da Tireoide/cirurgia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Adulto Jovem
4.
Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 55(10): 899-904, 2020 Oct 07.
Artigo em Zh | MEDLINE | ID: mdl-33036503

RESUMO

Objective: To summarize the clinical experience in transoral endoscopic thyroidectomy via sublingual and vestibular approach (TOETSLVA). Methods: We retrospectively reviewed the medical record of patients who underwent TOETSLVA in our department from November 2011 to May 2020, including 3 males and 95 females, aged from 18 to 57 years old. Initial 81 cases were categorized in "Period A (November 2011-November 2015)" and subsequent 17 cases in "Period B (August 2019-May 2020)" . Data about demographics, operation time and complications were collected. SPSS 22.0 software was used for statistical analysis. Results: In Period A, the average age of patients was (34.2±9.4) years old; the mean tumor diameter was (2.33±0.80) cm; postoperative pathology showed benign nodules in 76 cases and malignant carcinoma in 5 cases; there were 65 cases of unilateral subtotal thyroid lobectomy, 6 cases of isthmus lobectomy, and 5 cases of bilateral subtotal thyroid lobectomy, with the mean operation time of (132.70±47.22) min; in 5 cases of unilateral thyroid lobectomy with central lymph node dissection, the mean operation time was (185.4±31.40) min; postoperative neck infections occurred in 6 cases; temporary vocal cord paralysis occurred in 1 case, which it recovered within two months; and CO(2) gas embolism occurred in 2 cases. In Period B, the average age of patients was (35.1±8.5) years old; mean tumor diameter was (1.32±0.67) cm; postoperative pathology indicated malignant nodules in 15 cases and benign nodules in 2 cases; in 2 cases of unilateral thyroid lobectomy, the mean operation time was (153.5±34.64) min; in 15 cases of unilateral thyroid lobectomy with central lymph node dissection, the mean operation time was (123.73±14.26) min; and none of patients developed postoperative neck infections or CO(2) gas embolism. All patients had different degree of cutaneous numbness in the submandibular region after surgery, which recovered within 1-2 weeks. There were no complications such as postoperative secondary hemorrhage, permanent vocal cord paralysis, hypoparathyroidism in both the periods. The median follow-up time was 86 months (57-105 months) in Peroid A and 5 months (3-12 months) in Peroid B. During the follow-up periods, there were no obvious abnormalities in swallowing, chewing, oral sensory function and neck activity, and also no tumor recurrence or metastasis. Conclusions: TOETSLVA is a safe and feasible surgery method, with a good cosmetic result. This approach will not lead to a postoperative cutaneous numbness of the submandibular region for a long time.


Assuntos
Neoplasias da Glândula Tireoide , Tireoidectomia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esvaziamento Cervical , Recidiva Local de Neoplasia , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/cirurgia , Adulto Jovem
5.
Br J Anaesth ; 102(1): 117-22, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18987053

RESUMO

BACKGROUND: Perioperative use of dexmedetomidine is associated with reduction in postoperative analgesic requirements. This study examined whether dexmedetomidine added to i.v. patient-controlled analgesia (PCA) morphine could improve analgesia while reducing opioid-related side-effects. METHODS: In this double-blinded, randomized, controlled study, 100 women undergoing abdominal total hysterectomy were allocated to receive either morphine 1 mg ml(-1) alone (Group M) or morphine 1 mg ml(-1) plus dexmedetomidine 5 microg ml(-1) (Group D) for postoperative i.v. PCA, which was programmed to deliver 1 ml per demand with a 5 min lockout interval and no background infusion. Cumulative PCA requirements, pain intensities, cardiovascular and respiratory variables, and PCA-related adverse events were recorded for 24 h after operation. RESULTS: Compared with Group M, patients in Group D required 29% less morphine during the 0-24 h postoperative period and reported significantly lower pain levels from the second postoperative hour onwards and throughout the study. Whereas levels of sedation were similar between the groups at each observational time point, decreases in heart rate and mean blood pressure from presurgery baseline at 1, 2, and 4 h after operation were significantly greater in Group D (by a range of 5-7 beats min(-1) and 10-13%, respectively). The 4-24 h incidence of nausea was significantly lower in Group D (34% vs 56.3%, P<0.05). There was no bradycardia, hypotension, oversedation, or respiratory depression. CONCLUSIONS: The addition of dexmedetomidine to i.v. PCA morphine resulted in superior analgesia, significant morphine sparing, less morphine-induced nausea, and was devoid of additional sedation and untoward haemodynamic changes.


Assuntos
Analgesia Controlada pelo Paciente/métodos , Analgésicos não Narcóticos/administração & dosagem , Analgésicos Opioides/administração & dosagem , Dexmedetomidina/administração & dosagem , Morfina/administração & dosagem , Dor Pós-Operatória/prevenção & controle , Adulto , Analgésicos não Narcóticos/efeitos adversos , Analgésicos Opioides/efeitos adversos , Pressão Sanguínea/efeitos dos fármacos , Dexmedetomidina/efeitos adversos , Método Duplo-Cego , Esquema de Medicação , Combinação de Medicamentos , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Histerectomia , Infusões Intravenosas , Pessoa de Meia-Idade , Morfina/efeitos adversos , Náusea e Vômito Pós-Operatórios/induzido quimicamente
6.
Br J Anaesth ; 101(4): 542-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18640992

RESUMO

BACKGROUND: Nalbuphine, a mixed agonist-antagonist opioid, has a potential to attenuate the mu-opioid effects and to enhance the kappa-opioid effects. However, when morphine and nalbuphine are mixed together, the clinical interactions in different combining ratios on analgesic effect and adverse events are unknown. METHODS: This randomized, double-blind controlled study investigated five different combining ratios of morphine and nalbuphine in 311 patients undergoing gynaecologic operations. The concentrations [morphine (mg ml(-1))]/[nalbuphine (mg ml(-1))] were 1/0 in Group 1, 0.75/0.25 (ratio 1:3) in Group 2, 0.5/0.5 (ratio 1:1) in Group 3, 0.25/0.75 (ratio 3:1) in Group 4, and 0/1 in Group 5. Patient-controlled analgesia (PCA) requirement, postoperative pain, and adverse events were evaluated throughout the postoperative 24 h period. RESULTS: Twenty-four hour PCA requirements were similar among the five groups. Verbal rating scores for pain were statistically higher in Groups 2 and 4 than in Group 3. The incidences of pruritus were higher in Group 1 (15.6%) than in Group 2 (6.2%), Group 3 (3.4%), Group 4 (1.6%), and Group 5 (0%). The incidences and severity of dizziness, nausea, and vomiting were not significantly different. CONCLUSIONS: The interaction between morphine and nalbuphine in PCA admixture on analgesia is additive. Combinations of morphine and nalbuphine in PCA can decrease the incidence of pruritus, and the antipruritus effect is ratio-dependent. This may provide a novel combination strategy of opioid agonist and agonist-antagonist for postoperative pain management after gynaecologic surgery.


Assuntos
Analgesia Controlada pelo Paciente/métodos , Analgésicos Opioides/administração & dosagem , Morfina/administração & dosagem , Nalbufina/administração & dosagem , Dor Pós-Operatória/prevenção & controle , Adolescente , Adulto , Idoso , Analgesia Controlada pelo Paciente/efeitos adversos , Analgésicos Opioides/efeitos adversos , Antieméticos/administração & dosagem , Método Duplo-Cego , Esquema de Medicação , Combinação de Medicamentos , Humanos , Infusões Intravenosas , Pessoa de Meia-Idade , Morfina/efeitos adversos , Nalbufina/efeitos adversos , Medição da Dor/métodos , Náusea e Vômito Pós-Operatórios/induzido quimicamente , Náusea e Vômito Pós-Operatórios/tratamento farmacológico
7.
J Formos Med Assoc ; 93 Suppl 3: S142-8, 1994 Dec.
Artigo em Zh | MEDLINE | ID: mdl-7606172

RESUMO

Clinical and epidemiological studies were performed on 1,184 cases of urolithiasis treated in the Department of Urology, Poh Ai Hospital. The incidence of urolithiasis was 147/100,000 population in 1991. The highest incidence was found in patients in their 50s. The male to female ratio was 2.9:1. There were 895 cases with single stones, and 289 cases with multiple stones. The ratio of upper to lower urinary tract stones was 13.6:1. Among the hospitalized patients, 673 cases (56.8%) underwent surgical treatment and 511 cases (43.2%) received conservative treatment with spontaneous stone passage. Among 1071 cases of upper urinary tract calculi, 567 cases (52.9%) underwent surgical treatment: 236 cases (41.6%) were treated by endoscopic surgery, 176 cases (31.0%) were treated by open-surgery and 131 cases (23.1%) by extracorporeal shock wave lithotripsy. Among 79 cases of lower urinary tract calculi, 75 cases (94.9%) were treated surgically: 68 cases (90.7%) by transurethral endoscopic surgery and 7 cases (9.3%) by cystolithotomy. According to analysis of 365 stones, the most frequent type was calcium-containing stones (92.3%). Pyuria was noted in 250 out of 1,086 (23.0%) cases. Bacteriuria was noted in 202 out of 914 (22.1%) cases. Concerning organisms isolated from the urine, Staphylococcus epidermidis was found most frequently (55/202). Stone patients increased in number during the summer season (July and August). Systematic questionnaires completed by the patients with urolithiasis, lead us to the following conclusions: 1) 50.7% (216/438) of patients gave a past history of urolithiasis, and 2) family histories showed that males whose siblings had urolithiasis were at the highest risk of uolithiasis, followed by those whose fathers had a history of urolithiasis.


Assuntos
Cálculos Urinários/epidemiologia , Adulto , Idoso , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Taiwan/epidemiologia
8.
Sheng Li Xue Bao ; 43(2): 199-203, 1991 Apr.
Artigo em Zh | MEDLINE | ID: mdl-1648794

RESUMO

In the present study, the effects of microiontophoretically applied U-50488 on the spontaneous discharge of respitation related units (RRUs) in nucleus ambiguus or rats were observed. Of 96 RRUs recorded, U-50488 produced depressant effect on 51 units, excitative effect on 11 units, excitation followed by depression on 6 units, depression followed by excitation on 3 units. The remaining 25 units were not influenced. Naloxone administered iontophoretically not only blocked U-50488-induced depression in 12 out of 16 units, but also blocked U-50488-induced excitation in 2 units. Duration of the depression produced by U-50488 was remarkably longer than that of excitation. The result suggested that kappa receptor might be involved in respiratory regulation and that the subtype of opiate receptors which mediates depression and excitation effect might not be the same.


Assuntos
Bulbo/fisiologia , Pirrolidinas/farmacologia , Respiração/fisiologia , (trans)-Isômero de 3,4-dicloro-N-metil-N-(2-(1-pirrolidinil)-ciclo-hexil)-benzenoacetamida , Animais , Eletrofisiologia , Feminino , Iontoforese , Masculino , Bulbo/efeitos dos fármacos , Naloxona/farmacologia , Ratos , Ratos Endogâmicos , Receptores Opioides/fisiologia
9.
Sheng Li Xue Bao ; 42(4): 390-6, 1990 Aug.
Artigo em Zh | MEDLINE | ID: mdl-2175947

RESUMO

In the present study, it was observed that ohmefentanyl (OMF) affected microiontophoretically applied spontaneous discharges of respiration related units (RRUs) in the nucleus ambigus of rats. Of 96 RRUS recorded, 48 units were depressed following OMF application, 14 units increased in discharges, 14 units increased and then decreased, 9 units decreased and then increased. The remaining 11 units were not influenced. Naloxone administered iontophoretically not only blocked OMF-induced depression in 11 out of 15 units, but blocked OMF-induced facilitation in 5 out of 6 units. U-50488 administered microiontophoretically antagonized OMF-induced depression in 9 out of 13 units. Duration of the depression produced by OMF was much longer than that of the facilitation. The result suggests that the subtype of opiate receptors mediating the depression seen to be different from that responsible for the facilitation.


Assuntos
Fentanila/análogos & derivados , Bulbo/fisiologia , Respiração/fisiologia , Animais , Eletrofisiologia , Feminino , Fentanila/farmacologia , Iontoforese , Masculino , Ratos , Ratos Endogâmicos , Receptores Opioides/fisiologia
10.
Sheng Li Xue Bao ; 44(6): 562-8, 1992 Dec.
Artigo em Zh | MEDLINE | ID: mdl-1338815

RESUMO

It was observed that ohmefentanyl (OMF) and U-50488, when applied microiontophoretically, affected the spontaneous discharges of respiration related units (RRUs) in the nucleus of solitary tract of rat. Of the 44 RRUs recorded, OMF produced depressive effect in 21, excitatory in 7, biphasic effect in 5 while 11 units were not affected. Naloxone administered iontophoretically blocked both the depressive (6 out of 7) and the excitatory units (2 out of 3). Of the 45 RRUs recorded, U-50488 produced depressive effect in 15, excitatory in 5, biphasic effect in 3, while 22 units were not affected. Naloxone blocked both the U-50488 depression (7 out of 9) and excitation (1 out of 2) effect. U-50488 antagonized OMF-induced depression in 4 out of 6 units. The results suggest that depression and excitation produced by OMF and U-50488 may be mediated by different subtypes of opiate receptor.


Assuntos
Fentanila/análogos & derivados , Bulbo/fisiologia , Pirrolidinas/farmacologia , Respiração/fisiologia , (trans)-Isômero de 3,4-dicloro-N-metil-N-(2-(1-pirrolidinil)-ciclo-hexil)-benzenoacetamida , Animais , Depressão Química , Eletrofisiologia , Feminino , Fentanila/farmacologia , Iontoforese , Masculino , Naloxona/farmacologia , Pirrolidinas/antagonistas & inibidores , Ratos , Ratos Wistar , Receptores Opioides/efeitos dos fármacos , Respiração/efeitos dos fármacos
11.
Kaohsiung J Med Sci ; 17(8): 401-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11715839

RESUMO

Real-time ultrasound (US) was used to analyze the morphological characteristics of periportal collateral circulation (PPCC) and the hepatic artery in hepatocellular carcinoma (HCC) patients with portal vein invasion (PVI). During a 5-year interval, a total of 17 HCC patients with main portal vein thrombosis and detectable periportal vessels were collected: 14 men and 3 women, aged 27 to 76 years old. We examined these patients' periportal vessels by real-time US, then differentiated PPCC from hepatic artery by duplex Doppler US. We analyzed the morphological appearances of real-time US imaging of PPCC and the hepatic artery. Our results showed that the PPCC was always torturously worm-like in appearance on real-time US, and the hepatic artery usually had a linear channel appearance on real-time US. When these two kinds of vessels were seen simultaneously along the pathway of a thrombosed portal vein, the inner vessel was always the hepatic artery with linear channel structure, and the outer vessel was always PPCC with a torturously worm-like structure. In conclusion, real-time US is a useful and reliable modality in detecting periportal vessels and differentiating PPCC from the hepatic artery.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Circulação Colateral , Neoplasias Hepáticas/diagnóstico por imagem , Veia Porta/patologia , Adulto , Idoso , Carcinoma Hepatocelular/patologia , Feminino , Artéria Hepática/diagnóstico por imagem , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Ultrassonografia
12.
Hinyokika Kiyo ; 38(12): 1349-55, 1992 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-1288222

RESUMO

Between August 1987 and December 1990, 546 patients were admitted to the department of Urology at the Poh Ai Hospital of I-Lan, Taiwan, R.O.C. for the treatment of urinary stones. These urinary stone cases accounted for 50 to 60% of all urology patients admitted. The incidence of urolithiasis in I-Lan was estimated at 147/100,000 population in 1990. There were 402 male patients and 144 female patients, The male to female ratio was 2.8: 1. There were 450 upper urinary tract stones (kidney, ureter) in 314 males and 136 females, and 79 lower urinary tract stones (bladder, urethra) in 72 males and 7 females. The ratio of upper to lower urinary tract stones was 6:1. Endourological treatments such as percutaneous nephrolithotripsy and transurethral ureterolithotripsy have increased rapidly in recent years. A summary of the present analysis for composition of 365 stones follows. The most frequent type was calcium-containing stone (92.3%), followed by infection stone (4.7%), then uric acid (UA) stone (3.0%). There were no UA stones found in the female patients. According to urinalysis criteria of more than 10 WBC/HPF (x 400), pyuria was found in 67 cases of 334 metabolic stones (20.1%), and 11 cases of 17 infection stones (67.7%). There were neither pediatric case of stone formation nor cystine stones.


Assuntos
Cálculos Urinários/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Oxalato de Cálcio/análise , Criança , Humanos , Japão , Pessoa de Meia-Idade , Fatores Sexuais , Taiwan/epidemiologia , Cálculos Urinários/química , Cálculos Urinários/terapia
13.
Eur J Surg Oncol ; 37(5): 448-51, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21345637

RESUMO

BACKGROUND: Placing a totally implantable venous access device (TIVAD) using the classical subclavian vein puncture method carries the risk of certain complications including hemothorax, pneumothorax and pinch-off syndrome. We set out to determine whether percutaneous axillary vein catheterization can decrease the incidence of these complications. METHOD: This is a prospective, observational, uni-institutional study. We analyzed the outcome of 113 TIVADs performed by ultrasound-assisted percutaneous axillary vein catheterization from Jun. 2008 to Dec. 2008. Junior residents novice to subclavian and axillary vein catheterization performed the procedures. Insertion and indwelling catheter complications were recorded. RESULT: In our study population, 100% of TIVAD placements were successful. 27 patients (23.9%) required 3 or more repeated punctures; only one patient (0.9%) had clinically insignificant pneumothorax. Neither arterial puncture nor brachial plexus injury was recorded in our study. CONCLUSION: Ultrasound-assisted percutaneous axillary vein catheterization for TIVAD is a safe and relatively simple method for inexperienced operators.


Assuntos
Veia Axilar/diagnóstico por imagem , Cateterismo Venoso Central/efeitos adversos , Cateterismo Venoso Central/métodos , Cateteres de Demora , Cateterismo Venoso Central/instrumentação , Cateteres de Demora/efeitos adversos , Hemotórax/etiologia , Hemotórax/prevenção & controle , Humanos , Pneumotórax/etiologia , Pneumotórax/prevenção & controle , Estudos Prospectivos , Veia Subclávia , Ultrassonografia
17.
Res Commun Chem Pathol Pharmacol ; 24(2): 313-27, 1979 May.
Artigo em Inglês | MEDLINE | ID: mdl-111326

RESUMO

Polychlorinated biphenyls (PCBs) are widespread environmental pollutants which have been shown to be carcinogenic. One possible mechanism for the apparent carcinogenicity of PCBs is their metabolism to phenolic metabolites through an arene oxide intermediate, with the arene oxide that is formed being the ultimate mutagenic or carcinogenic species. The ability of a tetrachlorobiphenyl and its phenolic and arene oxide metabolites to cause single strand breaks in DNA was therefore examined. 2,2',5,5'-TCB-3,4-epoxide was more potent in causing DNA single strand breaks than either 2,2',5,5'-TCB or a mixture of 3-hydroxy and 4-hydroxy-2,2',5,5'-TCB. These results support the idea that PCB epoxide may be involved in PCB carcinogenesis.


Assuntos
DNA de Cadeia Simples/metabolismo , Bifenilos Policlorados/farmacologia , DNA de Cadeia Simples/isolamento & purificação
18.
Res Commun Chem Pathol Pharmacol ; 21(3): 485-96, 1978 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-151904

RESUMO

The possible toxicological properties of 2,5,2',5'-tetrachlorobiphenyl (TCB), 4-hydroxy-2,5,2',5'-tetrachlorobiphenyl (TCB-OH), and 2,5,2',5'-tetrachlorobiphenyl-3,4-oxide (TCB-oxide) were evaluated in three bioassay systems. Incubation of rat hepatocyte plasma membranes with 50 microgram/ml of TCB-OH decreased the activity of Mg2+-ATPase by approximately 90%, whereas approximately half of the enzyme activity remained after the TCB or TCB-oxide treatment. All three compounds were found to be inactive in the Salmonella/microsome mutagenicity assay. Only TCB-OH possessed potent cytotoxic activity against all four S. tymphimurium strains tested. It affects the viability of TA 1537 by as much as 40% even at concentrations as low as 1 microgram/ml. These data suggest the potential toxicological significance of metabolic activation by the hepatic microsomal mixed-function oxidases.


Assuntos
Mutagênicos , Bifenilos Policlorados/farmacologia , Adenosina Trifosfatases/antagonistas & inibidores , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/enzimologia , Células Cultivadas , Fígado/efeitos dos fármacos , Fígado/enzimologia , Bifenilos Policlorados/toxicidade , Ratos , Salmonella typhimurium/efeitos dos fármacos
19.
Proc Natl Acad Sci U S A ; 98(4): 1601-6, 2001 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-11171997

RESUMO

The two widely coexpressed isoforms of beta-arrestin (termed beta arrestin 1 and 2) are highly similar in amino acid sequence. The beta-arrestins bind phosphorylated heptahelical receptors to desensitize and target them to clathrin-coated pits for endocytosis. To better define differences in the roles of beta-arrestin 1 and 2, we prepared mouse embryonic fibroblasts from knockout mice that lack one of the beta-arrestins (beta arr1-KO and beta arr2-KO) or both (beta arr1/2-KO), as well as their wild-type (WT) littermate controls. These cells were analyzed for their ability to support desensitization and sequestration of the beta(2)-adrenergic receptor (beta(2)-AR) and the angiotensin II type 1A receptor (AT(1A)-R). Both beta arr1-KO and beta arr2-KO cells showed similar impairment in agonist-stimulated beta(2)-AR and AT(1A)-R desensitization, when compared with their WT control cells, and the beta arr1/2-KO cells were even further impaired. Sequestration of the beta(2)-AR in the beta arr2-KO cells was compromised significantly (87% reduction), whereas in the beta arr1-KO cells it was not. Agonist-stimulated internalization of the AT(1A)-R was only slightly reduced in the beta arr1-KO but was unaffected in the beta arr2-KO cells. In the beta arr1/2-KO cells, the sequestration of both receptors was dramatically reduced. Comparison of the ability of the two beta-arrestins to sequester the beta(2)-AR revealed beta-arrestin 2 to be 100-fold more potent than beta-arrestin 1. Down-regulation of the beta(2)-AR was also prevented in the beta arr1/2-KO cells, whereas no change was observed in the single knockout cells. These findings suggest that sequestration of various heptahelical receptors is regulated differently by the two beta-arrestins, whereas both isoforms are capable of supporting receptor desensitization and down-regulation.


Assuntos
Arrestinas/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Receptores de Angiotensina/metabolismo , Transdução de Sinais/fisiologia , Animais , Arrestinas/fisiologia , Linhagem Celular , AMP Cíclico/metabolismo , Humanos , Camundongos , Camundongos Knockout , Fosfatidilinositóis/metabolismo , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiologia , Receptor Tipo 1 de Angiotensina , Receptores Adrenérgicos beta 2/genética , Receptores de Angiotensina/genética , beta-Arrestina 1 , beta-Arrestina 2 , beta-Arrestinas
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