Intratesticular pressure after testicular torsion as a predictor of subsequent spermatogenesis: a rat model

What’s known on the subject? and What does the study add? Testicular torsion results in atrophy rates of more than 25% despite prompt surgical management, and there is no reliable intraoperative critieria to judge the viability of the testis, except the testicular appearance after scrotal incision. We demonstrated that less reduction of ITP after detorsion correlated with worse subsequent spermatogenesis. This result suggests that ITP can be the index to determine removal of the affected testis during surgery.

OBJECTIVE

? To assess the correlation between intratesticular pressure (ITP) after testicular torsion and subsequent testicular function using a rat model and to show that ITP at surgery is a useful predictor of future spermatogenesis.

MATERIALS AND METHODS

? Fourteen rats were divided into a torsion group (n= 7) and a control group with sham operation (n= 7). ? Torsion was created by 720° rotation of the left testis in a counter‐clockwise direction. ? Using a handheld compartment monitor, the ITP of the torsed testes was measured three times: before torsion (pre‐torsion), just before torsion repair (pre‐detorsion) and 5 min after torsion repair (post‐detorsion). ? We evaluated the correlation between ITP and testicular weight, epididymal sperm count or pathological findings, such as the seminiferous tubule diameter (STD) and the modified Johnsen’s score, 4 weeks after surgery.

RESULTS

? Mean (se) pre‐torsion, pre‐detorsion and post‐detorsion ITP values in the torsion group were 5.9 (2.5), 19.7 (10.7) and 8.2 (4.8) cm H₂O, respectively. ? The ITP in torsed testes significantly increased after torsion (P < 0.01) and decreased after detorsion (P < 0.01). ? Strong correlations were observed between the reduction of ITP after detorsion and testicular weight (r= 0.87, P < 0.05), epididymal sperm count (r= 0.94, P < 0.05), STD (r= 0.87, P < 0.05) or the Johnsen’s score (r= 0.99, P < 0.001).

CONCLUSION

? A smaller reduction in ITP after detorsion can be a risk factor for subsequent disturbance of spermatogenesis, suggesting that ITP can be an index for determining whether the affected testis should be removed after testicular torsion.     

Interferon alpha-2a and vinblastine in the treatment of metastatic renal carcinoma

Twenty patients with measurable metastatic renal cell carcinoma (RCC) were treated with interferon alpha-2a (18 X 10(6) IU i.m. 3 times weekly) in combination with vinblastine sulfate (0.1 mg/kg i.v. every 3 weeks). Objective responses in the lungs, bone and liver metastases were observed in 5 of 18 evaluable patients. Dose reduction of interferon alpha-2a (to 9 X 10(6) IU i.m. 3 times weekly) was necessary in 7 patients due to intolerable flu-like side effects and leukopenia (nadir 3,500 leukocytes/mm3). Tolerance was good in 55% of cases. Objective clinical response was observed in 27.7% of patients, and only 38.8% progressed. It is necessary to perform further studies, varying the therapeutic schedules, in order to elicit a better control of the toxic effects and a greater objectiveness of the clinical response.     

Predictive value of ischaemia-modified albumin in spermatogenesis in an experimental testicular torsion model

Our aim was to measure the ability of ischaemia-modified albumin (IMA) to predict testicular histopathological damage in the testes of rats with short- and long-term ischaemia using experimental testicular torsion and subsequent reperfusion via detorsion.21 Wistar Albino rats were randomized into three groups. The sham group was subjected to a mid-scrotal incision only. The 4- and 8-hr T/D (Torsion/Detorsion) groups were subjected to left testicular torsion by twisting the testes by 720 degrees counterclockwise. 2 cc venous blood samples were taken from the sham group after the mid-scrotal incision, and from the 4- and 8-hr T/D groups after 4 and 8 hr respectively. After that, the 4- and 8-hr T/D groups were subjected to detorsion. Two days later, orchiectomy was performed. Ischaemia-modified albumin levels were significantly different among the groups at 48 hr prior to orchiectomy (reperfusion; p = .003). Based on the results of the paired comparisons, it was found that IMA levels of the sham group were significantly higher than those of the 4- and 8-hr T/D groups (p = .002 and .009 respectively). Our study has showed that IMA may be used to predict ischaemia/reperfusion injury, which is another complication that may occur following detorsion in testicular torsion.     

Angiotensin II dependent testicular fibrosis and effects on spermatogenesis after vasectomy in the rat

PURPOSE: Vasectomy induces testicular interstitial fibrosis in time dependent fashion and inhibits spermatogenesis. We investigated the contribution of angiotensin II (Ang II) to the development of interstitial fibrosis after vasectomy. MATERIALS AND METHODS: Bilateral vasectomy was performed in 8-week-old Wistar rats and the testes were harvested 1 to 24 weeks after vasectomy. Interstitial fibrosis was evaluated by Masson's trichrome staining. Western blotting and immunohistochemistry were done to examine the expressions of heat shock protein 47 (HSP47), HNE (4-hydroxy-2,3-nonenal) and transforming growth factor-beta1 (TGF-beta1). The antioxidative agent N-acetylcysteine (NAC), the Ang II type 1 receptor antagonist losartan or the Ang converting enzyme inhibitor enalapril was given orally for 24 weeks to vasectomized rats. Spermatogenesis was evaluated by testicular weight and the percent of haploid cells was analyzed by flow cytometry. RESULTS: Vasectomy significantly increased interstitial fibrosis (more than 8 weeks) and induced the expression of HSP47, HNE modified protein and TGF-beta1. TGF-beta1 and HSP47 immunoreactivity was localized to Leydig cells and fibroblasts. NAC or losartan but not enalapril inhibited the expression of these molecules induced by vasectomy. Increased interstitial fibrosis and impaired spermatogenesis were partially abrogated by NAC or losartan administration. CONCLUSIONS: There is Ang II type 1 receptor dependent fibrosis after vasectomy. Oxidative condition is considered to trigger and promote these fibrogenic processes. Ang II contributes to the regulation of intratesticular autocrine or paracrine functions after vasectomy.     

提睾肌在无张力疝修补术后对大鼠生精功能的保护意义

【摘要】 目的 探究提睾肌在无张力疝修补术后对大鼠生精功能的保护意义。方法〓选择成年SD大鼠建立实验动物模型,分正常对照组(NC组)、假手术组(Sham组)、手术组,手术组又分为OP1组和OP2组,前者保留提睾肌的完整性后者完全切断提睾肌。于术后90天分别将各组大鼠术侧睾丸组织HE染色观察病理变化,流式细胞仪测定各级生精细胞数量变化。结果〓OP1组生精过程轻度异常,生发上皮紊乱,生精细胞层数减少,可见大量的精子细胞和精子,各级生精细胞与Sham组相比差异无统计学意义。OP2组大鼠睾丸呈退行性变化,生发上皮紊乱,生精细胞层数减少,单倍体细胞及二倍体细胞数量减少,与OP1组及Sham组比较P<0.05。结论〓提睾肌对雄性大鼠的生精功能具有保护作用,男性腹股沟疝患者行无张力修补术无张力修补术时,应尽可能保护提睾肌的连续性和完整性。     

Isoflurane does not further impair microvascular vasomotion in a rat model of subarachnoid hemorrhage

PURPOSE: Since isoflurane is known to attenuate endothelium-dependent dilation (EDD) in normal cerebral arterioles, we examined whether the anesthetic has a similar effect and further impairs EDD in vessels exposed to SAH. METHODS: Autologous blood was introduced in the subarachnoid space and the parietal lobe harvested. Control animals were sacrificed without introduction of blood. The response of microvessles to the endothelium-dependent dilator adenosine diphosphate (ADP) 10(-9)-10(-4) M, the endothelium-independent dilator nitroprusside 10(-9)-10(-4) M, and ET-1 10(-13)-10(-8) M was measured by videomicroscopy in the presence of 0-2 minimum alveolar concentration (MAC) of isoflurane. RESULTS: Isoflurane attenuated EDD to ADP in control vessels [66 +/- 5% (control) vs 27 +/- 11% (2 MAC) dilation to ADP 10(-4) M, P < 0.05]. Although SAH was associated with reduced dilation to ADP, exposure to isoflurane did not further impair dilation to ADP after SAH [26 +/- 3% (SAH) vs 21 +/- 5% (SAH/2 MAC) dilation to ADP 10(-4) M, P = NS]. Dilation to nitroprusside was not affected by isoflurane or SAH. Constriction to ET-1 was reduced by 2 MAC of isoflurane [21 +/- 1% (control) vs 13 +/- 5% (2 MAC) constriction to ET-1 10(-8) M, P < 0.05], but not by 1 MAC of isoflurane in control vessels. Constriction to ET-1 was greatly attenuated by 1 or 2 MAC of isoflurane after SAH [32 +/- 5% (SAH) vs 18 +/- 4% (SAH/2 MAC) constriction to ET-1 10(-8) M, P < 0.05]. CONCLUSION: In rats, isoflurane does not further impair EDD after SAH and modulates the constrictive response to ET-1. Such an effect of isoflurane would not predispose the SAH-exposed vessels to vasospasm.     

In vitro drug sensitivity testing of human testicular germ cell tumours with cytostatic drugs and interferon alpha-2b

In spite of the significant advances in the chemotherapy of germ cell neoplasms, some patients do not achieve disease-free status and ultimately die from their diseases. Therefore, it is reasonable to select the best chemotherapeutic agents in these patients byin vitro drug sensitivity assay (IVDSA) in order to apply the most effective agent in case of resistance to primary chemotherapy. Fresh operative cells from 12 testicular germ cell tumours (TGCT) were culturedin vitro. Sensitivity of the tumour cells to interferon-alpha (IFN-alpha), cisplatin, mitomycin C, vinblastine, doxorubicin, etoposide, bleomycin, vincristine (VCR) were tested by a colorimetric assay using MTT. A preexposure viability over 75% was essential for IVDSA. Sensitivity was determined by a more than 50±2 SD% reduction from the control absorbance. All eight drugs in their high concentrations exhibited cell proliferation inhibition in 83.3±100% of TGCT. But in low concentrations efficacy of IFN and VCR were found to be lower than the others (33.3% and 58.3%, respectively). The results indicated that although TGCT are highly sensitive to various agents IVDSA may help to identify the effective agents which might be necessary for second line chemotherapy in a small percentage of patients.     

Validation of a prediction model and its predictors for the histology of residual masses in nonseminomatous testicular cancer

PURPOSE: We validated a prediction model for histology of residual retroperitoneal masses, either benign or tumor, in patients treated with chemotherapy for metastatic nonseminomatous testicular cancer. MATERIALS AND METHODS: We studied 276 patients treated with chemotherapy before retroperitoneal lymph node dissection at Indiana University Medical Center between 1985 and 1999. A previously developed prediction model was modified to provide predictions for the Indiana population based on 5 predictors. For these predictors, including teratomatous elements in the primary tumor, pre-chemotherapy tumor markers (alpha-fetoprotein and human chorionic gonadotropin), size of the residual mass and reduction in mass size, univariate and multivariate odds ratios were determined. The modified model was evaluated by calculating the concordance statistic and studying model reliability. RESULTS: All odds ratios from univariate and multivariate analyses were in the expected directions. The modified model had good discriminative ability (concordance statistic 0.79). However, the predicted probabilities for benign tissue were generally too high due to the low prevalence of benign tissue (76 of 276 cases or 28%). CONCLUSIONS: This study confirms the predictive ability of formerly identified predictors for the histology of residual retroperitoneal masses in testicular cancer. However, the previously developed prognostic model must be adjusted for the local overall ratio of benign versus tumor histology to provide reliable predictions in the Indiana population.     

Interferon Alfa-2b or Not 2b? Significant Differences Exist in the Decision-Making Process between Melanoma Patients Who Accept or Decline High-Dose Adjuvant Interferon Alfa-2b Treatment

BACKGROUND: Patients with thick (Breslow>4 mm) primary melanoma and/or regional nodal metastasis have a high risk of tumor recurrence. High-dose adjuvant interferon (IFN) alfa-2b offers/=50% risk of recurrence/disease-related mortality and offered IFN. Telephone surveys delineated reasons behind patients' decisions to accept IFN. RESULTS: Acceptors, 60 of 135 (45%), decided to take IFN alfa-2b whereas 75 of 135 (55%) declined. Being female (OR, 2.4; 95% CI, 1.17-5.03; p=.017) and positive SLN status (OR, 2.2; 95% CI, 1.01-4.97; p=.048) were strongly associated with patients who chose IFN. Acceptors of IFN were younger, more influenced by physicians, and less affected by depression and side effect profile (p<.05 for all). Decliners were more concerned by strained relationships with family and social life (p<.05). CONCLUSIONS: Gender and positive SLN were predictive of high-risk melanoma patients' acceptance of IFN treatment. Physician insight into melanoma patients' therapeutic decision-making process can guide patients through this difficult disease.     

Trimetazidine has protective effects on spermatogenesis in a streptozotocin‐induced diabetic rat model

The aim of this study was to investigate the protective effects of trimetazidine (TMZ), as an antioxidant agent, on streptozotocin (STZ)‐induced diabetic rats. A total of 50 male Sprague Dawley rats were randomly classified into five groups as follows: Group 1 (control), Group 2 (STZ‐induced diabetic rats), Group 3 (STZ‐induced diabetic rats treated orally with 1 cc/day isotonic saline), Group 4 (diabetic rats treated orally with 10 mg/kg/day TMZ) and Group 5 (diabetic rats treated orally with 20 mg/kg/day TMZ). After 8 weeks, orchiectomy was carried out. Histopathological and electron microscopic examinations were performed in all groups. In groups 1 and 5, the structural and ultra‐structural findings of the testicular tissue and spermatogenesis were found normal. In groups 2, 3 and 4, similar results were obtained in terms of the impaired testicular architecture and degeneration of spermatogenesis. The administration of an optimal dose of TMZ protects against the harmful effects of diabetes mellitus on spermatogenesis in rats. TMZ therapy can be used to maintain normal spermatogenesis in diabetic rats.     

Gasoline exhaust damages spermatogenesis through downregulating α6‐integrin and β1‐integrin in the rat model

The health influence of air pollution has been an international public health concern. Increasing evidence has suggested that air pollution has been associated with decreased sperm quality. However, the underlying molecular mechanisms are still not fully elucidated. We aimed to verify whether gasoline exhaust leads to reproductive impairment by injuring spermatogonial stem cells and explore its underlying molecular mechanism. Twenty male Sprague‐Dawley rats were randomly divided into two groups: the exposure group (n = 10) and the control group (n = 10). After 6‐month exposure, the sperm count and morphology were determined. The histological changes in the seminiferous tubules were examined by HE staining. The expression of α6‐integrin and β1 ‐ integrin was assessed with Quantitative RT‐PCR, Western blot and Immunohistochemical staining. Compared with control group, male rats exposed to gasoline exhaust showed significantly reduced sperm count, increased sperm abnormality rate and the total number of spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids were decreased. (all p < .01). The expression levels of α6‐integrin and β1 ‐ integrin in the exposure group were significantly lower than those in the control group (all p < .01). Our study showed that exposure to gasoline exhaust caused impairment to spermatogonial stem cells through downregulating α6‐integrin and β1 ‐ integrin.     

The correlation between serum epidermal growth factor/testicular epidermal growth factor receptor and spermatogenesis in rat

<正>Objective: To investigate the correlation between epidermal growth factor (EGF)/testicular epidermal growth factor receptor (EGF-R) and spermatogenesis in rat. Methods: Forty mature male Spraque-Dauley (SD) rats were randomly assigned to four groups, ten rats in each: sham operation group (SOG), sialoadenectomy group(SG), sialoade-nectomy group with injection of EGF (0. 25 μg·kg-1·d-1, SG-EGF Ⅰ) and sialoadenectomy group with injection of EGF (0. 50 μg·kg-1·d-1 , SG-EGF Ⅱ). The rats were routinely feed, and blood and testes were obtained on the 48th day after the operation. Serum EGF concentrations were determined by radioimmunoassay (RIA) , expression of EGF-R in testes was examined by the immunohistochemical method, and the spermatogenesis was pathologically checked. Results: Serum EGF levels in SG-EGFIand SG decreased significantly when compared with those of SOG (P<0. 05 and P< 0. 01, respectively). The testicular function of spermatogenesis showed a moderate to severe impairment in SG. The expression of EGF-R in Leydig cells decreased in SG(P<0. 05). The two dosage groups of EGF replacement had different effects. There were no significant differences of EGF-R expression in testicular germ cells, Sertoli cells and Leydig cells in SOG, SG-EGFⅠand SG-EGFⅡ(P>0. 05). Conclusion: EGF may play an important role in the regulation of spermatogenesis. Serum EGF concentration and high expression of EGF-R in Leydig cells have a positive correlation with spermatogenic function of the testes.     

大鼠血清表皮生长因子和睾丸表皮生长因子受体与精子生成的相关性

目的　探讨血清表皮生长因子 ( EGF)和睾丸组织表皮生长因子受体 ( EGF-R)与大鼠精子生成的关系。　方法　 40只性成熟期雄性 SD大鼠 ,随机分为假手术组( SOG)、去颌下腺组 ( SG)、去颌下腺加腹腔注射 EGF I组 ( SG-EGF I)和 II组 ( SG-EGFII) ,每组 1 0只。SG-EGF I和 SG-EGF II分别腹腔内注射 EGF0 .2 5和 0 .50 μg·kg- 1·d- 1。大鼠常规喂养 48d,断头取血和睾丸。放射免疫法检测血清 EGF水平 ,病理检查睾丸生精功能和免疫组织化学检测睾丸组织 EGF-R的表达。　结果　大鼠血清 EGF水平SG-EGF I组明显下降 ( P<0 .0 5) ,SG组有非常显著下降 ( P<0 .0 1 ) ;睾丸生精功能中、重度障碍 ;间质细胞 EGF-R表达明显减少 ( P<0 .0 5)。补充不同剂量的 EGF对睾丸生精功能有不同影响。 SOG、SG-EGF I和 SG-EGF II大鼠睾丸生精细胞、支持细胞及间质细胞 EGF-R表达无显著性差异 ( P>0 .0 5)。　结论　EGF对精子发生具重要的调控作用 ,血清 EGF水平和睾丸间质细胞 EGF-R高表达与睾丸生精功能呈正相关     

Predicting retroperitoneal histology in postchemotherapy testicular germ cell cancer: a model update and multicentre validation with more than 1000 patients

OBJECTIVES: Surgical resection of postchemotherapy retroperitoneal lymph nodes is often performed in patients with advanced nonseminomatous testicular germ cell cancer. We previously developed a model to predict the probability that the lymph nodes contain only necrotic or fibrotic (benign) tissue versus mature teratoma and viable cancer (tumour) to identify patients who actually need resection. The present study used an updated model with new patient data and studied the validity of the updated model across various settings. METHODS: We combined data of 544 patients from the original model with data of 550 new patients and performed a new logistic regression analysis, which included the same six predictors: histology of the primary tumour, prechemotherapy serum levels of alpha-fetoprotein, human chorionic gonadotropin, lactate dehydrogenase, residual mass size measured on computed tomography, and change in mass size. The validity of the updated model was studied in individual centres. Calibration of the predicted probabilities was assessed graphically and with the Hosmer-Lemeshow test. Discrimination was studied with the concordance (c)-statistic. RESULTS: The updated model had slightly different, although more precise, regression coefficients. Statistically nonsignificant Hosmer-Lemeshow tests confirmed good calibration in most centres. The c-statistic for all centres except one exceeded 0.80. The updated model was valid over the complete range of predicted probabilities across a broad spectrum of centres. CONCLUSIONS: This finding gives confidence in the applicability of the model to select patients for resection, particularly patients with small residual masses and low predicted probabilities of benign tissue (i.e., substantial predicted risks of residual tumour).