RESUMEN
OBJECTIVES: To evaluate the safety and effectiveness of soft-tissue augmentation of the urethral sphincter with calcium hydroxylapatite (CaHA; Coaptite) compared with glutaraldehyde cross-linked bovine collagen (Contigen) in female patients with stress urinary incontinence due to intrinsic sphincter deficiency and without associated urethral hypermobility. METHODS: This 12-month prospective, randomized, comparative, multicenter, single-blind, parallel, clinical trial of CaHA and collagen for soft-tissue augmentation of the urethral sphincter in the treatment of stress urinary incontinence enrolled 296 women. Up to five injections were performed in the first 6 months of the trial. Twelve-month postinjection efficacy data were available for 231 patients. RESULTS: The results indicated that CaHA and collagen were both well tolerated in this study. No systemic adverse events were observed with either product. We used the Stamey Urinary Incontinence Scale to grade the improvement, which was the primary endpoint of the study. At 12 months, 83 (63.4%) of 131 CaHA patients compared with 57 (57.0%) of 100 collagen patients showed improvement of one Stamey grade or more (P = 0.34). More CaHA patients required only one injection (n = 60; 38.0%) during the study compared with the Contigen patients (n = 36; 26.1%; P = 0.034). Also, the average total volume of material injected during the course of the study was less for CaHA than for collagen (4.0 mL versus 6.6 mL, respectively; P <0.0001). CONCLUSIONS: The results of the study have demonstrated that Coaptite is an appropriate and well-tolerated treatment for patients with incontinence due to intrinsic sphincter deficiency. This new soft-tissue augmentation material has a good safety profile and appears to provide durable improvement.
Asunto(s)
Colágeno/uso terapéutico , Durapatita/uso terapéutico , Calidad de Vida , Incontinencia Urinaria de Esfuerzo/terapia , Adulto , Anciano , Animales , Bovinos , Estudios Cruzados , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Probabilidad , Estudios Prospectivos , Valores de Referencia , Medición de Riesgo , Método Simple Ciego , Resultado del Tratamiento , Incontinencia Urinaria de Esfuerzo/diagnóstico , UrodinámicaRESUMEN
OBJECTIVES: To evaluate the responsiveness of composite scales to change over time in a clinical trial of patients with interstitial cystitis (IC). The measurement of symptoms in IC includes the O'Leary-Sant Symptom and Problem Indexes and the University of Wisconsin Interstitial Cystitis Inventory and scales that measure the individual symptom domains of pain/discomfort, urgency, and voiding frequency. METHODS: The data were derived from a randomized clinical trial conducted by the Interstitial Cystitis Clinical Trials Group. Participants met the National Institutes of Health-National Institute for Diabetes, and Digestive and Kidney Diseases criteria for IC and reported at least moderate pain and frequency. The primary endpoint was a patient-reported global response assessment (GRA) at 24 weeks. Secondary endpoints included the three composite indexes, pain/discomfort and urgency, and 24-hour frequency. Responsiveness was assessed by comparing symptom score changes against response categories defined by the GRA. RESULTS: Of the 121 subjects in the original trial, 94 with complete data were included. All three composite indexes were sensitive to subject improvement over time as measured by the GRA. A 1.2-point change in the O'Leary-Sant indexes and a 3.1-point change in the Wisconsin IC inventory corresponded to a one-category change in the GRA. Individual symptoms were also responsive. The correlation was high among the changes in the six outcome measures. CONCLUSIONS: The three composite symptom scales are responsive to change over time in patients with IC. These indexes provide important insight into symptom changes and are recommended as secondary endpoints in future clinical trials of IC. Additional endpoints addressing individual symptom domains should also be considered to aid in the evaluation of effect mechanisms.
Asunto(s)
Cistitis Intersticial/diagnóstico , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la EnfermedadRESUMEN
PURPOSE: Biliverdin reductase is an oxidoreductase unique among all enzymes characterized to date in having dual pH/dual cofactor requirement - NADH and NADPH at 6.7 and 8.7, respectively. The protein shows extensive microheterogeneity that is caused by post-translational modification. The reductase converts the heme degradation product, biliverdin, to bilirubin. Bilirubin has been shown to inhibit responses of human lymphocytes, including phytohemagglutinin-induced proliferation, interleukin-2 production, and antibody dependent and independent cell mediated cytotoxicity. In addition to acting as an antioxidant, it inhibits protein phosphorylation and activity of enzymes such as protein kinase C and NADPH oxidase. This research was to evaluate whether renal cell carcinoma differs from normal tissue in regard to the expression and activity of the reductase. MATERIALS AND METHODS: Kidney tissue with or without visible renal carcinoma and normal kidney tissue from a brain dead patient were frozen at -80C shortly after removal. Ten microm. tissue sections were used for immunostaining of biliverdin reductase, pooled isolated tumors and surrounding tissue that did not contain visible tumor were used for Northern blot analysis of mRNA and Western blot analysis of protein. Enzyme activity was also measured in these preparations at pH 6.7 with NADH, and at pH 8.7 with NADPH. Ten additional formalin fixed specimens of renal cell carcinoma were also used for immunostaining. RESULTS: There was a striking increase in the reductase protein levels, as visualized by immunostaining in tumor tissue cells. The increase was also evident by Western blotting, and involved in increased transcription of biliverdin reductase as suggested by Northern blot analysis. The protein would also be detected in the infiltrating monocytes, macrophages, T cells and neutrophils as well as in circulating lymphocytes. The enzyme activity was nearly doubled in the tumor tissue, but selectively with NADH as the cofactor. CONCLUSION: Increases in biliverdin reductase expression and activity only with NADH is found in renal cell carcinoma. The net effects of this change are uncertain at present but several pathways, which could be affected by the reductase, may alter local physiology. Biliverdin reductase as a zinc metalloprotein may directly interact with other regulatory proteins, generation of increased bilirubin may alter immune function and increased enzyme activity may deplete NADH with contrasting consequence of blocking free radical formation and depleting cellular ATP. To the benefit of the host, the latter could culminate in tumor cell death.
Asunto(s)
Carcinoma de Células Renales/enzimología , Neoplasias Renales/enzimología , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Oxidorreductasas/metabolismo , Carcinoma de Células Renales/química , Activación Enzimática , Humanos , Concentración de Iones de Hidrógeno , Neoplasias Renales/química , NAD/metabolismo , NADP/metabolismo , Oxidorreductasas/análisisRESUMEN
OBJECTIVES: To determine the effectiveness, safety, and impact on patient quality of life (QOL) of a novel transurethral microwave thermoablation system for the treatment of benign prostatic hyperplasia (BPH). METHODS: A total of 169 patients with BPH were randomized to undergo a 1-hour microwave (n = 125) or sham (n = 44) procedure using the Urologix Targis thermoablation system on an outpatient basis, without general or regional anesthesia. Symptoms, flow rates, and QOL scores were determined before the study procedure and periodically thereafter up to 6 months. RESULTS: Mean American Urological Association (AUA) score in the microwave group diminished 50% (P <0.0005) by the 6-month evaluation (10.5, 95% confidence interval [CI] 9.2 to 11.8) compared with baseline values (20.8, 95% CI 19.8 to 21.9). The sham group also exhibited lower postprocedural AUA scores; however, the magnitude of the postprocedural decline in AUA score in the microwave group was significantly greater (P <0.01) than that in the sham group. Half the microwave group had an AUA score of less than 9 by 6 months, and the decrease in symptoms was similar among patients with initially moderate versus initially severe symptoms. Mean peak urinary flow rate (Qmax) in the microwave group increased 51% (P <0.0005) by 6 months to 11.8 mL/s (95% CI 10.7 to 13.0) versus a pretreatment value of 7.8 mL/s (95% CI 7.4 to 8.2). The magnitude of the postprocedural increase in Qmax was significantly greater in the microwave than the sham group (P <0.05). In nearly half the microwave group (47%), Qmax increased 50% or more by 6 months compared with 24% of the sham group. Microwave treatment resulted in a significantly greater (P <0.05) positive impact on patient QOL than did the sham procedure. By 6 months, the QOL score in microwave-treated patients (2.2, 95% CI 1.9 to 2.4) averaged 48% lower (P <0.0005) than that at baseline (4.2, 95% CI 4.0 to 4.4). Significantly greater durability of treatment effects was also evident with microwave than with sham treatment, as judged by the higher proportion of microwave-treated patients (98.4%) requiring no further treatment during the 6-month study period versus 83.3% of sham control patients (P <0.0005). Microwave treatment was well tolerated, and complications were generally minor, readily manageable, and transitory. CONCLUSIONS: The microwave thermoablation system proved to be an effective and safe treatment modality for BPH, with a positive impact on patient QOL.
Asunto(s)
Electrocoagulación/métodos , Microondas/uso terapéutico , Hiperplasia Prostática/cirugía , Anciano , Anciano de 80 o más Años , Procedimientos Quirúrgicos Ambulatorios , Anestesia Local , Intervalos de Confianza , Método Doble Ciego , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Hiperplasia Prostática/fisiopatología , Calidad de Vida , Seguridad , Resultado del Tratamiento , Micción/fisiología , UrodinámicaRESUMEN
PURPOSE: To compare sonoelasticity imaging versus ultrasound (US) in detection of prostate cancer. MATERIALS AND METHODS: Sonoelasticity imaging and US were performed on 10 prostatectomy specimens in which cancer was detected at previous biopsy. Six patients had no palpable lesions at digital rectal examination. Specimens were imaged axially at the apex, middle, and base of the gland to correlate with location of pathologic sections. All images were interpreted blindly and prospectively, and results were compared with pathologic findings. RESULTS: Sensitivity and specificity with sonoelasticity imaging were 85% and 84%, respectively, and 30% and 100% with standard US when compared with pathologic findings. Sixty-four percent of pathologically confirmed tumors detected at sonoelasticity imaging were isoechoic on conventional US images. CONCLUSION: In this limited study, sonoelasticity imaging was more sensitive for tumor detection and more accurate for assessment of tumor location than was conventional US.
Asunto(s)
Adenocarcinoma/diagnóstico por imagen , Próstata/diagnóstico por imagen , Neoplasias de la Próstata/diagnóstico por imagen , Anciano , Elasticidad , Humanos , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Prostatectomía , Sensibilidad y Especificidad , Ultrasonografía/métodos , VibraciónRESUMEN
Neurotrophic ulceration of the face is a rare but well recognized sequel to division of the trigeminal nerve. Trauma is an important contributory factor and thought to be due in part to paraesthesiae, which encourages picking and scratching, with resultant chronic and persistent ulceration. A case is described of an 82-year-old woman with severe trigeminal neurotrophic ulceration which improved substantially with pimozide, given for treatment of unrelated paranoid symptoms. The possible relevance of this to the established use of pimozide in delusional parasitosis is briefly discussed.
Asunto(s)
Trastornos del Conocimiento/tratamiento farmacológico , Dermatosis Facial/tratamiento farmacológico , Nariz , Pimozida/uso terapéutico , Úlcera Cutánea/tratamiento farmacológico , Nervio Trigémino/patología , Anciano , Anciano de 80 o más Años , Atrofia/complicaciones , Femenino , HumanosRESUMEN
Presently we describe, for the first time, induction of microsomal heme oxygenase-1 (HO-1) mRNA and protein in response to ischemia/reperfusion and therefore define HO-1 as stress protein in the kidney. Specifically, Northern blot analysis of kidneys of rats subjected to bilateral ischemia for 30 min revealed an increase of 8- to 10-fold in the level of 1.8 Kb HO-1 mRNA 6 hr after reperfusion. The increase in transcript level was maintained when assessed after 24 hr. The levels of 1.3 and 1.9 Kb transcripts for the second isozyme of HO, HO-2, were decreased at both time points. The increase in HO-1 mRNA was reflected in HO-1 protein level, as judged by Western blot analysis and at the level of activity as judged by the rate of bilirubin formation. An absence of change in adrenal HO-1 mRNA level subsequent to renal ischemia/reperfusion suggested that the induction of kidney HO-1 did not reflect a generalized response of the rat organs to stress; rather, it was a target organ specific response. Moreover, in kidneys subjected to ischemia 6 and 24 hr after reperfusion, significant increases in the cellular content of heme were observed; heme is a known inducer of HO-1 synthesis. Ischemia/reperfusion also adversely affected concentration of cytochrome P-450 in both mitochondrial and the microsomal fractions of the kidney. We suggest that increase in tissue heme levels may be a significant factor in damage caused by ischemia/reperfusion to renal tissue, whereby the metalloporphyrin promotes oxygen-free radical formation.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Hemo Oxigenasa (Desciclizante)/biosíntesis , Hemo/fisiología , Isquemia/enzimología , Isoenzimas/biosíntesis , Riñón/irrigación sanguínea , Riñón/enzimología , ARN Mensajero/biosíntesis , Animales , Pigmentos Biliares/metabolismo , Northern Blotting , Inducción Enzimática , Hemo Oxigenasa (Desciclizante)/genética , Isquemia/genética , Isoenzimas/genética , Riñón/fisiología , Masculino , Microsomas/metabolismo , Mitocondrias/metabolismo , Ratas , Ratas Sprague-Dawley , Reperfusión/efectos adversosRESUMEN
We have examined the toxicity of trans-platinum (trans-diamminedichloroplatinum II) to heme and hemoprotein metabolism in the kidney of glutathione (GSH)-depleted rats and compared it with that produced by cis-platinum. Unlike cis-platinum treatment (7.0 mg/kg, i.v.) which caused after 7 days significant increases in cytochromes P450 and b5, and a marked decrease in porphyrin content of the kidney, trans-platinum alone (7 mg/kg, i.v.) did not elicit notable changes in these variables when measured 1 or 7 days after treatment. Also, cis-platinum treatment significantly altered the heme degradation pathway by increasing the activity of heme oxygenase and decreasing that of biliverdin reductase; trans-platinum treatment did not elicit a response in these activities. However, when rats were given the inhibitor of GSH synthesis, D,L-buthionine-S,R-sulfoximine (BSO), the subsequent administration (2 hr later) of trans-platinum produced, in 1 day, the spectrum of responses that were mediated by cis-platinum after 7 days. In the kidneys of rats treated with BSO plus trans-platinum the concentration of platinum measured only about 50% of that detected in the kidneys of rats treated with trans-platinum alone. In the liver, trans-platinum by itself or in combination with BSO was ineffective in altering the measured variables of heme metabolism. The possibility that similarity between cis-platinum and trans-platinum plus BSO may extend to systems other than heme metabolism, e.g. GSH synthesis and degradation, was examined. cis-Platinum caused significant inhibition of both renal gamma-glutamyl synthetase and gamma-glutamyl transpeptidase after 7 days, but not after 1 day. Twenty-four hours after treatment, BSO + trans-platinum caused inhibition of gamma-glutamylcysteine synthetase activity, whereas this activity in animals treated with BSO alone had returned to control values. At this time point, neither oxidized glutathione (GSSG)-reductase nor gamma-glutamyl transpeptidase activity was affected by trans-platinum + BSO treatment. The findings suggest that GSH constitutes an important defense mechanism against trans-platinum alteration of heme metabolism and may play a role in cellular accumulation of the drug in an inactive complex. It is proposed that BSO treatment, despite resulting in a diminished intracellular concentration of trans-platinum, allows reaction of the metal complex with target molecules by virtue of its ability to deplete GSH.
Asunto(s)
Glutatión/metabolismo , Riñón/efectos de los fármacos , Metionina Sulfoximina/análogos & derivados , Compuestos Organoplatinos/farmacología , Animales , Butionina Sulfoximina , Sistema Enzimático del Citocromo P-450/metabolismo , Sinergismo Farmacológico , Glutatión/deficiencia , Hemo Oxigenasa (Desciclizante)/metabolismo , Riñón/análisis , Riñón/enzimología , Masculino , Metionina Sulfoximina/farmacología , Platino (Metal)/análisis , Porfirinas/metabolismo , Ratas , Ratas Endogámicas , Estereoisomerismo , Fracciones Subcelulares/metabolismoRESUMEN
The effect of systemic glutathione (GSH) depletion on sensitization of bladder cancer cells to various antineoplastic agents was investigated using murine model, MBT-2. Subcutaneous injection(s) of buthionine sulfoximine (BSO) significantly depleted the GSH content in the tumor and organs. BSO pretreatment produced significant enhancement in the antitumor effect of cyclophosphamide (CY), though it failed to sensitize the tumors to doxorubicin hydrochloride (Adriamycin), cisplatin, mitomycin C, JM-8, methotrexate, vinblastine, and tumor necrosis factor. Mice tolerated cytotoxic agents alone and in combination with BSO except for cisplatin in combination with BSO. A 29 percent (4/14) mortality rate was observed in mice treated with BSO and divided schedule of cisplatin.
Asunto(s)
Antimetabolitos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Carcinoma de Células Transicionales/tratamiento farmacológico , Glutatión/antagonistas & inhibidores , Metionina Sulfoximina/análogos & derivados , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Animales , Antineoplásicos/administración & dosificación , Butionina Sulfoximina , Femenino , Glutatión/análisis , Riñón/análisis , Hígado/análisis , Pulmón/análisis , Metionina Sulfoximina/administración & dosificación , Ratones , Ratones Endogámicos C3H , Miocardio/análisis , Células Tumorales CultivadasRESUMEN
Treatment of rats with 25 or 50 mg/kg cyclosporin A for 6 days elicited vastly different responses in hepatic and renal heme and drug metabolism activities. In the liver, cytochrome P-450 concentration was decreased significantly (to 70-75% of the control). This was accompanied by a marked reduction in benzo[a]pyrene hydroxylase activity (to 20-28% of the control). Aniline hydroxylation was also decreased, but to a lesser extent (to 77% of the control). In contrast, in the kidney cytochrome P-450 concentration was significantly increased to (145-170% of the control), along with a modest decrease in benzo[a]pyrene hydroxylation activity. In this organ, the concentration of porphyrins was severely decreased (to 30% of the control). Also, the activities of delta-aminolevulinate (ALA) synthetase and ALA dehydratase, as well as that of heme oxygenase, were inhibited. It is suggested that in the kidney the inhibition of degradation, rather than an enhanced rate of synthesis of the heme molecule, contributes to the observed increase in cytochrome P-450 concentration. In the liver, the decrease in the cytochrome concentration could not be explained in terms of an alteration in the rate of heme biosynthesis or degradation. Therefore, the observed decrease in cytochrome P-450 concentration could reflect the direct inactivation of the hemoprotein or regulation of apoprotein production by cyclosporin and/or its metabolite(s). The possible relevance of the observations to cyclosporin nephrotoxicity is discussed.
Asunto(s)
Ciclosporinas/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Hemo/metabolismo , Riñón/enzimología , Hígado/enzimología , Anilina Hidroxilasa/metabolismo , Animales , Benzopireno Hidroxilasa/metabolismo , Inhibidores Enzimáticos del Citocromo P-450 , Hemo Oxigenasa (Desciclizante)/metabolismo , Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Masculino , NADPH-Ferrihemoproteína Reductasa/metabolismo , Ratas , Ratas EndogámicasRESUMEN
Male Sprague Dawley rats were treated with buthionine sulfoximine (BSO) and cisplatin in different doses and schedules to optimize the chemoprotective effect of BSO against cisplatin nephrotoxicity. BSO at 4 mmol/kg, administered s.c. 2 h prior to cisplatin, resulted in normal blood urea nitrogen (BUN) levels in rats treated with 3 or 4 mg/kg cisplatin, and modestly, but significantly reduced the toxicity of cisplatin at 5 mg/kg. Administration of BSO (4 mmol/kg) at intervals ranging from 0 to 16 h prior to cisplatin (5 mg/kg) resulted in a significant reduction in BUN values. A BSO dose as low as 0.04 mmol/kg was found to be as effective as 4 mmol/kg against nephrotoxicity associated with cisplatin at 4 mg/kg. Repetitive injections of BSO (1 mmol/kg every 12 h, four times, beginning 2 h prior to cisplatin) significantly inhibited elevations of BUN associated with higher-dose cisplatin (6 mg/kg), whereas a single BSO injection of 4 mmol/kg was ineffective. The degree and duration of renal glutathione depletion was related to the dose of BSO. Renal glutathione content following 4 mmol/kg BSO was 38% of control at 2 h and 40% at 24 h; following 0.04 mg/kg, glutathione was 47% at 2 h and almost 100% at 24 h. Simultaneous in vitro administration of BSO did not inactivate cisplatin cytotoxicity as measured by the colony-forming ability of MBT-2 cells in soft agar. These data indicate that repeated injections of BSO, beginning prior to cisplatin administration, would improve the nephroprotective effect without compromising the chemotherapeutic efficacy of cisplatin. It is suggested that the ability of BSO to reduce cisplatin nephrotoxicity may not correlate with the degree of renal glutathione depletion and that the mechanism of action is unlikely to involve direct inactivation of cisplatin.
Asunto(s)
Cisplatino/toxicidad , Riñón/efectos de los fármacos , Animales , Nitrógeno de la Urea Sanguínea , Butionina Sulfoximina , Relación Dosis-Respuesta a Droga , Glutatión/análisis , Riñón/metabolismo , Metionina Sulfoximina/farmacología , Ratas , Ratas EndogámicasRESUMEN
The unprecedented ability of cyclosporin A, when given for six days at a dose of 25 mg/kg/d or 50 mg/kg/d, to cause a marked and sustained increase in renal glutathione (GSH) concentration in rat kidney is described. This response was particular to the kidney insofar as the GSH concentration in the liver was not increased in response to a lower dose of cyclosporin and was decreased in the liver of animals treated with the higher dose of the drug. The increase in kidney GSH concentration did not appear to be due to an increased rate of production or to an inhibition of the degradation of the tripeptide. This suggestion is based on the finding that the activities of the GSH synthesis pathways, GSSG-reductase and gamma-glutamylcysteine synthetase, were unchanged or decreased, respectively, and those of the catabolic enzymes, GSH-peroxidase and gamma-glutamyltranspeptidase, were unchanged or increased, respectively. It is suggested that the elevation of renal GSH content in the face of diminished synthetic capacity and an apparent increased utilization may result from an enhanced uptake of GSH as the result of alterations caused by cyclosporin in the renal transport system.
Asunto(s)
Ciclosporinas/toxicidad , Glutatión/metabolismo , Riñón/efectos de los fármacos , Animales , Glutamato-Cisteína Ligasa/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/metabolismo , Riñón/metabolismo , Masculino , Ratas , Ratas Endogámicas , gamma-Glutamiltransferasa/metabolismoRESUMEN
DL-Buthionine-(S,R)-sulfoximine (BSO), a glutathione-depleting agent, was found to diminish the nephrotoxic effect of cisplatin (cis-diamminedichloroplatinum). Pretreatment of rats with BSO (4 mmol/kg s.c.) 2 h prior to cisplatin, either as a single dose of 5 mg/kg or at a daily dose of 2.5 mg/kg for 3 consecutive days, resulted in diminished elevations of plasma BUN concentration and decreased cisplatin-induced inhibition of renal gamma-glutamylcysteine synthetase and gamma-glutamyl transpeptidase activity measured 6 days following treatment. Administration of BSO prior to cisplatin at 7.5 mg/kg did not significantly alter the effect of cisplatin on either BUN concentration or enzyme activity. The influence of BSO pretreatment on the antitumor activity of cisplatin was studied using implantation of a murine bladder cancer (MBT-2) in C3H mice. Pretreatment of mice with BSO (5 mmol/kg) did not influence cisplatin antitumor efficacy.
Asunto(s)
Cisplatino/toxicidad , Enfermedades Renales/inducido químicamente , Riñón/efectos de los fármacos , Metionina Sulfoximina/análogos & derivados , Animales , Butionina Sulfoximina , Carcinoma de Células Transicionales/tratamiento farmacológico , Cisplatino/uso terapéutico , Femenino , Glutamato-Cisteína Ligasa/análisis , Glutatión/análisis , Glutatión/biosíntesis , Riñón/enzimología , Riñón/metabolismo , Enfermedades Renales/metabolismo , Enfermedades Renales/prevención & control , Masculino , Metionina Sulfoximina/uso terapéutico , Ratones , Ratones Endogámicos C3H , Ratas , Ratas Endogámicas , Factores de Tiempo , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , gamma-Glutamiltransferasa/análisisRESUMEN
The treatment of rats with cis-platinum for 7 days caused a profound, and seemingly selective, decrease (70-80%) in the microsomal cytochrome P-450 levels in the testis. This decrease was accompanied by marked reductions (70-80%) in steroid 17 alpha-hydroxylase activity and in plasma testosterone concentration. The treatment of rats with human chorionic gonadotropin partially restored the cytochrome P-450 concentration and 17 alpha-hydroxylase activity and permitted the plasma testosterone level to approach control values. The effect of cis-platinum on the testicular cytochrome P-450 appeared unrelated to deficiencies in heme metabolic processes, in so far that neither was the activity of delta-aminolevulinate synthetase decreased, nor was that of heme oxygenase increased. These enzymes are rate-limiting in heme biosynthesis and degradation pathways, respectively. Also, the activities of uroporphyrinogen I synthetase, delta-aminolevulinate dehydratase, and ferrochelatase and the concentration of total porphyrins in the testis remained unchanged. The sodium dodecyl sulfate-gel electrophoresis of the microsomal preparation did not reveal a diminished level of apocytochrome; however, in this preparation, heme could not be detected in molecular weight regions corresponding to cytochrome P-450. The microsomal cytochrome b5 and the mitochondrial heme concentrations were not decreased in cis-platinum-treated rats. It is suggested that the mechanism of depletive action of cis-platinum on microsomal cytochrome P-450 involves an impairment of the effective assembly of heme and apoprotein moieties. It is further suggested that the anterior pituitary hormones control the factor(s) involved in this assembly, a process which is interrupted by cis-platinum.
Asunto(s)
Cisplatino/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Esteroides/biosíntesis , Testículo/efectos de los fármacos , Animales , Gonadotropina Coriónica/farmacología , Hemo/metabolismo , Hemoproteínas/metabolismo , Masculino , Microsomas/metabolismo , Ratas , Ratas Endogámicas , Testículo/metabolismoRESUMEN
Porous high-density polyethylene specimens were implanted in the femurs of mongrel canines. At the end of the residency period (3 or 6 months), the animals were sacrificed and the implants were retrieved. The work-of-fracture of the implant specimens was then determined using the technique of Tattersall and Tappin. The work required to fracture a specimen in three-point bending by controlled crack propagation through a triangular cross section was obtained directly from the load-deflection curve. The area of the resulting fracture surface was measured by macrophotographic techniques, and the work-of-fracture was calculated as work per unit area. The implants were subsequently sectioned and examined microradiographically to determine the extent of bone ingrowth. Bone specimens adjacent to the implants and porous high-density polyethylene controls (no ingrowth) were also tested to determine their work-of-fracture. The results showed that bone adjacent to the implant specimens had a higher work-of-fracture than normal medial, canine femoral bone and was not appreciably different from the composite. The work-of-fracture of porous high-density polyethylene was not significantly increased by an increase in bone infiltration, and this anomalous behavior was attributed to a degradation of the polyethylene during implant residence. Control studies supported this hypothesis.
Asunto(s)
Huesos/cirugía , Fracturas Óseas/fisiopatología , Polietilenos , Prótesis e Implantes , Animales , Fenómenos Biomecánicos , Perros , Fracturas Óseas/patología , Microscopía Electrónica de Rastreo , OsteogénesisRESUMEN
A carbon dioxide requirement for growth of Streptococcus sanguis was readily demonstrated in a fermentor where the gas atmosphere could be controlled. Growth at a maximum rate occurred immediately in response to the appropriate CO(2) concentration; growth stopped when CO(2) was deleted. Washed inocula consisting of exponentially growing cells required a minimum of 2.4% CO(2), postexponential phase cells needed 1.2 to 1.8% CO(2) immediately and 2.4% CO(2) shortly thereafter, whereas stationary phase cells required three sequential increases in CO(2) from 0.3 to 1.8 to 2.4% within the first 90 min of growth. These CO(2) concentrations permitted each inoculum to initiate growth immediately at the same maximum rate. These results also showed that physiologically "old" cells had the same capacity for growth as "young" cells when the CO(2) concentrations were appropriate for the type of inoculum. Continued exponential growth of the culture at the same optimum rate required 2.4% CO(2). Lower concentrations of CO(2) were rate limiting and the resulting exponential rate was proportional to the CO(2) concentration. The "normal" lag period of S. sanguis appears to be an artifact induced by a CO(2) deficiency.