Vascular endothelial growth factor restores erectile function through inhibition of apoptosis in diabetic rat penile crura

PURPOSE: Vascular endothelial growth factor (VEGF) is known as a multifunctional protein with roles in angiogenesis stimulation and apoptosis inhibition. We hypothesized that intracavernous administration of VEGF would recover erectile dysfunction due to diabetes by protection from apoptosis in the penile cavernosum. MATERIALS AND METHODS: A total of 30, 6-month-old male Sprague-Dawley rats were divided into 2 large groups, namely 20 with diabetes and 10 healthy controls. The diabetic group received intraperitoneal injection of streptozotocin (STZ) to induce diabetes. Intracavernous injection of VEGF was administered to randomly selected STZ diabetic rats 6 weeks after STZ injections. Erectile functional studies were performed in 10 STZ and 10 STZ plus VEGF rats at 12 weeks. After completion of the functional study the penile crura were collected for molecular and immunohistochemical studies. RESULTS: Mean intracavernous pressure in the diabetic group was significantly lower than in controls and low pressure was significantly recovered by VEGF treatment. Gene expression of pro-apoptotic and anti-apoptotic factors were present in the control, diabetic and VEGF treated groups. However, anti-apoptotic protein expression was lacking in the diabetic group and it was recovered by VEGF treatment. The apoptotic index in the diabetic group was significantly higher than in controls and this index was significantly decreased in the VEGF treated group. CONCLUSIONS: The decrease in and recovery of intracavernous pressure correlated significantly with a variation in anti-apoptotic protein expression in the diabetic and VEGF treated groups. To our knowledge this is the first study to show that intracavernous injection of VEGF restores erectile dysfunction through the inhibition of apoptosis in diabetic rats.     

Health effects of cadmium exposure in the general environment in Japan with special reference to the lower limit of the benchmark dose as the threshold level of urinary cadmium

OBJECTIVES: This study investigates renal dysfunction in areas without known environmental cadmium pollution and calculates the threshold level of urinary cadmium. METHODS: Urinary total protein, beta2-microglobulin (beta2-MG), and N-acetyl-beta-D-glucosaminidase (NAG), used as indicators of renal dysfunction, and urinary cadmium concentration, used as an indicator of cadmium exposure, were measured in two sets of 24-hour urine samples from each of 828 participants (410 men, 418 women), aged 40-59 years and living in three areas without any known environmental cadmium pollution. In multiple regression and logistic regression analyses the association between indicators of cadmium exposure and indicators of renal dysfunction were studied. The lower 95% confidence limit of the dose (benchmark dose) corresponding to a 5% (BMDL5) or 10% (BMDL10) level of each indicator of renal dysfunction above the background level) was calculated as the threshold level of urinary cadmium. RESULTS: With all the expressed units [g creatinine(-1) and day(-1)] in the multiple regression analysis, the partial regression coefficients showed a significant association between urinary cadmium concentration and total protein, beta2-MG, and NAG for both genders, except for total protein for women (g creatinine(-1) and day(-1). The same results were obtained for both genders in the logistic regression analysis. The BMDL10 was 0.6-1.2 microg/g creatinine and 0.8-1.6 microg/day for the men and 1.2-3.6 microg/g creatinine, and 0.5-4.7 microg/day for the women. CONCLUSIONS: Cadmium exposure and the levels of the indicators of renal dysfunction were associated among the men and women aged 40-59 years in areas without any known environmental cadmium pollution. The threshold level of urinary cadmium in Japan seems to be almost the same as in Belgium and Sweden.     

A validation study on food composition tables for the international cooperative INTERMAP study in Japan

Objective The INTERMAP Study is an international cooperative study on the relationship between macro- and micro-nutrient intakes and blood pressure. The present study—ancillary to INTERMAP—is to evaluate validity of the INTERMAP Tables of Food Composition in Japan (ITJ) formulated by modifying the Standard Tables of Food Composition in Japan (STJ), including factoring in changes in weight and nutrient composition of individual foods due to cooking. Methods With chemical analytical values of 96 meals prepared in two university hospitals in Japan as the “gold standard”, validity of calculated values based on the ITJ was examined for six major components (energy, protein, lipid, carbohydrate, sodium, potassium) by comparison of mean values, correlation, and linear regression analysis. Results Although both the ITJ-based and STJ-based calculated values for all six components were significantly higher than the analytical values, differences from the analytical values were generally less marked for the ITJ-based values than for the STJ-based values. The STJ-based values were significantly higher than the ITJ-based values for protein and potassium. Analytical values showed slightly stronger correlations with the ITJ-based calculated values (r=0.876 for total energy, r=0.789 for lipid, r=0.832 for potassium) than with the STJ-based calculated values, except for carbohydrates. Conclusions The ITJ was considered to have greater validity than the STJ. To obtain more accaurate data in nutritional surveys, food composition tables in which changes in nutrient compositions due to cooking methods are taken into consideration should be used.     

Ophthalmology

The Headache Classification Subcommittee of the International Headache Society classifies headaches related to eyes as "Headache attributed to disorder of eyes" in the International Classification of Headache Disorders; 2nd Edition(ICHD-II). It consists of "Headache attributed to acute glaucoma", "Headache attributed to refractive errors", "Headache attributed to heterophoria or heterotropia(latent or manifest squint)", "Headache attributed to ocular inflammatory disorder". But other causes of headache related to eyes exist. For example, dry eye causes the headache. This article mentions to "Headache attributed to disorder of eyes" in ICHD-II, and additionally, describes other causes of headache associated with disease of eye.     

CYP3A4 substrate selection and substitution in the prediction of potential drug-drug interactions

The complexity of in vitro kinetic phenomena observed for CYP3A4 substrates (homo- or heterotropic cooperativity) confounds the prediction of drug-drug interactions, and an evaluation of alternative and/or pragmatic approaches and substrates is needed. The current study focused on the utility of the three most commonly used CYP3A4 in vitro probes for the prediction of 26 reported in vivo interactions with azole inhibitors (increase in area under the curve ranged from 1.2 to 24, 50% in the range of potent inhibition). In addition to midazolam, testosterone, and nifedipine, quinidine was explored as a more "pragmatic" substrate due to its kinetic properties and specificity toward CYP3A4 in comparison with CYP3A5. Ki estimates obtained in human liver microsomes under standardized in vitro conditions for each of the four probes were used to determine the validity of substrate substitution in CYP3A4 drug-drug interaction prediction. Detailed inhibitor-related (microsomal binding, depletion over incubation time) and substrate-related factors (cooperativity, contribution of other metabolic pathways, or renal excretion) were incorporated in the assessment of the interaction potential. All four CYP3A4 probes predicted 69 to 81% of the interactions with azoles within 2-fold of the mean in vivo value. Comparison of simple and multisite mechanistic models and interaction prediction accuracy for each of the in vitro probes indicated that midazolam and quinidine in vitro data provided the best assessment of a potential interaction, with the lowest bias and the highest precision of the prediction. Further investigations with a wider range of inhibitors are required to substantiate these findings.     

Generation of reactive oxygen species by neutrophils and endothelial cell injury in normal and preeclamptic pregnancies

The aim of this study was to investigate the role of neutrophil-derived reactive oxygen species on endothelial cell dysfunction in preeclampsia. We first assessed the correlation between nitrite and superoxide anion production in normal nonpregnant (n=10), normal pregnant (n=15), and preeclamptic women (n=12). We then examined neutrophil-mediated oxygen radical damage to human umbilical vein endothelial cells in vitro. Neutrophil superoxide release was measured by cytochrome C reduction; nitrite release was measured by the modified Griess reaction, and endothelial cell injury was measured by 51Cr release. N-formyl-methionyl-leucyl-phenylalanine-stimulated superoxide release by neutrophils was significantly increased in women with preeclampsia compared with the other 2 groups. Nitrite release by neutrophils was significantly decreased in preeclampsia compared with normal pregnancy. When neutrophils were pretreated with superoxide dismutase, nitrite release by neutrophils did not differ between normal pregnancy and preeclampsia, suggesting that excess superoxide anion in preeclampsia could reduce bioavailability of nitric oxide through neutrophil autocrine function. Neutrophil-mediated endothelial cell injury was significantly greater in women with preeclampsia than in the other 2 groups. Hydrogen peroxide was important in neutrophil-mediated endothelial cell injury in preeclampsia as catalase inhibited endothelial cell injury. When neutrophils were pretreated with NG-nitro-L-arginine methyl ester, neutrophil-mediated endothelial cell injury in preeclampsia was decreased, indicating a role for peroxynitrite formation as a mechanism of endothelial cell injury. In conclusion, the modulation of neutrophils causing superoxide production to dominate over nitrite release provides a reasonable explanation for endothelial cell dysfunction in preeclampsia.     

Analysis of limited fertility in intracytoplasmic sperm injection of sperm obtained by electroejactulation

Background and Aims :  We correlated findings in semen from patients with ejaculatory dysfunction with results of in vitro fertilization using their electroejaculated sperm.
Methods and Results :  Electroejaculation was carried out in six patients with the above-mentioned criteria for a total of eight times. Sperm was obtained in six attempts. Intracytoplasmic injection of these sperm was performed in 156 eggs. Sixty-seven eggs were fertilized; most of these were injected with motile sperm. Two women became pregnant, both after injection with motile sperm. As previously reported, electroejaculated sperm showed low motility and a low fertilization rate, but even motile sperm had a low fertilization rate.
Conclusion :  The results of the present study suggest the importance in fertilization of undetermined factors in addition to sperm motility. (Reprod Med Biol 2004; 3 : 9–12)