Thermal pain tolerance and pain rating in normal subjects: Gender and age effects.

BACKGROUND: Thermal detection thresholds and thermal pain thresholds are important in quantitative sensory testing. Although they have been well studied for assessing somatosensory function, the investigation of thermal pain tolerance has been insufficient. The aim of this study was to explore the characteristics of thermal pain tolerance and pain ratings in healthy subjects. METHODS: Cold pain tolerance (CPTol) and heat pain tolerance (HPTol) were tested in 213 healthy adults aged 18-81 years recruited from the local community. The thermal detection and thermal pain thresholds were also tested to investigate the association with pain tolerance. The visual analogue scale (VAS) was used for assessing pain severity immediately after the thermal pain and tolerance tests. RESULTS: The normality of the CPTol and HPTol was acceptable. Most participants rated the pain induced by the CPTol and HPTol testing as moderate. HPTol was lower in women than in men (p = 0.001), but CPTol did not differ between sexes. The pain ratings of CPTol and HPTol did not differ between sexes, but significant age effects were observed. The association of the tolerance temperature with pain ratings was weak, while those of pain ratings for CPTol and HPTol were strong (r = 0.87). CONCLUSIONS: Women were more sensitive to tolerance heat pain stimuli. Younger participants reported more pain for thermal pain and tolerance tests. SIGNIFICANCE: Thermal pain tolerance and pain rating for the thermal pain tolerance temperature depend on gender and age. Women are more sensitive to heat temperatures, young people rate more pain, and the pain ratings of heat and cold are strongly correlated.

Humanin protects against chemotherapy-induced stage-specific male germ cell apoptosis in rats.

Humanin (HN) has cytoprotective action on male germ cells after testicular stress induced by heat and hormonal deprivation. To examine whether HN has protective effects on chemotherapy-induced male germ cell apoptosis, we treated four groups of adult rats with (i) vehicle (control), (ii) HN, (iii) cyclophosphamide (CP); or (iv) HN+CP. To investigate whether the protective effects of HN on germ cells require the presence of Leydig cells, another four groups of rats were pre-treated with ethane dimethanesulfonate (EDS), a Leydig cell toxicant, to eliminate Leydig cells. After 3 days, when Leydig cells were depleted by EDS, we administered: (i) vehicle, (ii) HN, (iii) CP; or (iv) HN+CP to rats. All rats were killed 12 h after the injection of HN and/or CP. Germ cell apoptosis was detected by TUNEL assay and quantified by numerical count. Compared with control and HN (alone), CP significantly increased germ cell apoptosis; HN +CP significantly reduced CP-induced apoptosis at early (I-VI) and late stages (IX-XIV) but not at middle stages (VII-VIII) of the seminiferous epithelial cycle. Pre-treatment with EDS markedly suppressed serum and intratesticular testosterone (T) levels, and significantly increased germ cell apoptosis at the middle (VII-VIII) stages. CP did not further increase germ cell apoptosis in the EDS-pre-treated rats. HN significantly attenuated germ cell apoptosis at the middle stages in EDS pre-treated rats. To investigate whether HN has any direct effects on Leydig cell function, adult Leydig cells were isolated and treated with ketoconazole (KTZ) to block testosterone synthesis. HN was not effective in preventing the reduction of T production by KTZ in vitro. We conclude that HN decreases CP and/or EDS-induced germ cell apoptosis in a stage-specific fashion. HN acts directly on germ cells to protect against EDS-induced apoptosis in the absence of Leydig cells and intratesticular testosterone levels are very low.

Testosterone replacement ameliorates nonalcoholic fatty liver disease in castrated male rats.

Nonalcoholic fatty liver disease is common in developed countries and is associated with obesity, metabolic syndrome, and type 2 diabetes. T deficiency is a risk factor for developing these metabolic deficiencies, but its role in hepatic steatosis has not been well studied. We investigated the effects of T on the pathogenesis of hepatic steatosis in rats fed a high-fat diet (HFD). Adult male rats were randomly placed into four groups and treated for 15 weeks: intact rats on regular chow diet (RCD), intact rats on liquid HFD (I+HFD), castrated rats on HFD (C+HFD), and castrated rats with T replacement on HFD (C+HFD+T). Fat contributed 71% energy to the HFD but only 16% of energy to the RCD. Serum T level was undetectable in castrated rats, and T replacement led to 2-fold higher mean serum T levels than in intact rats. C+HFD rats gained less weight but had higher percentage body fat than C+HFD+T. Severe micro- and macrovesicular fat accumulated in hepatocytes with multiple inflammatory foci in the livers of C+HFD. I+HFD and C+HFD+T hepatocytes demonstrated only mild to moderate microvesicular steatosis. T replacement attenuated HFD-induced hepatocyte apoptosis in castrated rats. Serum glucose and insulin levels were not increased with HFD in any group. Immunoblots showed that insulin-regulated proteins were not changed in any group. This study demonstrates that T deficiency may contribute to the severity of hepatic steatosis and T may play a protective role in hepatic steatosis and nonalcoholic fatty liver disease development without insulin resistance.

The cytoprotective peptide humanin is induced and neutralizes Bax after pro-apoptotic stress in the rat testis.

We have previously demonstrated that the mitochondria-derived cytoprotective peptide humanin (HN), when administered intratesticularly to rats, rescues germ cells from apoptosis secondary to testicular stress of hormonal deprivation induced by gonadotropin-releasing hormone antagonist (GnRH-A). To decipher the cellular mechanisms of HN action in the amelioration of GnRH-A-induced germ cell apoptosis, adult male rats received the following treatments for 5 days: (i) daily intratesticular (IT) injections with saline (control); (ii) a single subcutaneous injection of GnRH-A on Day 1 and daily IT injection of saline; (iii) daily IT injection of synthetic HN; and (iv) GnRH-A injection on Day 1 and daily IT injection of HN (GnRH-A+HN). HN alone had no effect on germ cell apoptosis. GnRH-A increased germ cell apoptosis and BAX in the testicular mitochondrial fractions. Synthetic HN decreased germ cell apoptosis induced by GnRH-A and BAX in the mitochondria. We deduced that the cytoprotective action of synthetic HN on GnRH-A-induced germ cell apoptosis was mediated by attenuating p38 mitogen-activated protein kinase activity and increasing STAT3 phosphorylation. The effect of synthetic HN on the expression of endogenous rat HN in the testis was studied using rat HN specific antibody. GnRH-A treatment increased, but concomitant treatment with synthetic HN reduced endogenous rat HN expression in both cytosolic and mitochondrial fractions in testis. Co-immunoprecipitation experiments demonstrated that the increased rat HN was physically associated with BAX in the cytosolic testicular fractions after GnRH-A treatment. Double-immunofluorescence staining confirmed the co-localization of BAX and rat HN in the cytoplasm of Leydig cells and spermatocytes after GnRH-A treatment. We conclude that the cytoprotective effect of exogenously administered synthetic HN is mediated by interactions of endogenous rat HN with BAX in the cytoplasm preventing the entry of BAX to the mitochondria to govern the fate of germ cell survival or death during pro-apoptotic stress to the testis in rats.

Transplanted XY germ cells produce spermatozoa in testes of XXY mice.

XXY mouse has been characterized as an experimental model for men with Klinefelter's syndrome (XXY male phenotype). To test whether donor XY germ cells could proliferate and differentiate in the XXY testicular environment, donor testicular cells from adult (2-3 months old) and immature (10 days old) XY green fluorescence protein (GFP) transgenic mice were transplanted into the seminiferous tubules of adult (4-7 months old) and young (6 weeks old) XXY recipient mice respectively. Twelve weeks after transplantation, GFP positive spermatogonia were found in 21.74% (five out of 23) of adult XXY recipients who received adult donor cells. The GFP positive segments of seminiferous tubules were observed in 44.44% (four out of nine) young XXY recipients who received donor cells from 10 days old GFP mice. We found using immunohistochemistry and cell morphology that donor-derived GFP positive germ cells were spermatogonia, spermatocytes, round spermatids and spermatozoa in some of the seminiferous tubules of young XXY recipient mice. The results demonstrated that the donor XY germ cells were able to qualitatively complete spermatogenesis in some of the seminiferous tubules of XXY mice.

Microtubules are required for cytokeratin aggresome (Mallory body) formation in hepatocytes: an in vitro study.

Mallory bodies are cytokeratin-ubiquitin aggresomes that form in hepatocytes in many different chronic liver diseases. One of the key components in aggresome formation, not yet investigated in Mallory body formation, is the role of microtubules. An in vitro tissue culture assay is required to test for microtubule involvement in Mallory body formation so that Mallory body formation can be observed in the presence or absence of microtubule-disrupting agents. In this report, a new model of in vitro Mallory body formation was developed, which uses cultured hepatocytes isolated from drug-primed mice. When hepatocytes were incubated in the presence of antimicrotubule agents, they failed to form Mallory bodies. It is concluded that intact microtubules are required for Mallory body formation.

Heat shock proteins are present in mallory bodies (cytokeratin aggresomes) in human liver biopsy specimens.

Mallory bodies (MBs) are aggresomes, composed of cytokeratin and various other proteins, which form in diseased liver because of disruption in the ubiquitin-proteasome protein degradation pathway. Heat shock proteins (hsp's) are thought to be involved in this process because it was discovered that MB formation is induced by heat shock in drug-primed mice. It has been reported that ubiquitin and a mutant form of ubiquitin (UBB(+1)) are found in aggresomes formed in the neurons in Alzheimer's disease and in the liver MBs in various liver diseases. In addition, hsp 70 has been found in aggresomes in Alzheimer's and in MBs in drug-primed mice. Therefore, we hypothesized that hsp's might be involved in MB formation in human liver diseases. Liver biopsy sections were double-stained using ubiquitin and hsp 70 or 90b antibodies. Both hsps 70 and 90b were found in MBs in all liver diseases investigated including primary billiary cirrhosis, nonalcoholic steatohepatitis, hepatitis B and C, idiopathic cirrhosis, alcoholic hepatitis, and hepatocellular carcinoma. Ubiquitin and the hsp's colocalized in all MBs in the diseased liver sections. These results indicate that hsp involvement in MB formation is similar to that seen in aggresome formation in other conformational diseases.

Aggresome formation in liver cells in response to different toxic mechanisms: role of the ubiquitin-proteasome pathway and the frameshift mutant of ubiquitin.

Aggresomes form in cells when intracellular proteins undergo conformational changes, as in so-called conformational diseases. This phenomenon has been observed in the liver and brain and in cell culture in response to abnormal protein formation, such as mutant proteins. In the case of the brain the frameshift mutant ubiquitin (UBB+1) is involved. Mallory body formation in the liver is one example of this phenomenon in vivo. Mallory body formation is common in a variety of liver diseases of diverse pathogenesis. The study of the Mallory body forming model indicated that drug-conditioned hepatocytes form Mallory bodies when mice are given colchicine, ethanol, okadaic acid, or exposure to heat shock. These findings suggest that aggresome formation is a common pathway of liver injury due to diverse mechanisms. To further characterize the role of this common pathway, drug-primed mice were exposed to different types of liver injury, i.e., using such drugs as thioacetamide, galactosamine, tautomycin, and the proteasome inhibitor PS341. Mallory body formation was induced by treatment with all the toxins tested, giving credence to the proposal that aggresome formation in the liver is a common pathway in response to different primary mechanisms of liver injury. The frameshift mutant UBB+1 was invariably found to colocalize with ubiquitin in the Mallory body, indicating its essential involvement in the mechanism of MB formation.

Impairment of spermatogenesis in transgenic mice with selective overexpression of Bcl-2 in the somatic cells of the testis.

To explore the functional role of Bcl-2 in germ cell development, transgenic mice carrying 6 kilobases of the inhibin-alpha promoter were generated to express human bcl-2 gene product in the gonads. Although female transgenic mice demonstrated decreased follicle apoptosis, enhanced folliculogenesis, and increased germ cell tumorigenesis, the adult males exhibited variable impairment of spermatogenesis. The degree of damage ranged from tubules with intraepithelial vacuoles of varying sizes to near atrophied tubules consisting of Sertoli cells and a few spermatogonia. Although there was no significant change in body weight, an approximately 34% decrease in testicular weights was noted in transgenic animals compared with wild-type mice. Gamete maturation, assessed by determining the percentage of tubules with advanced (steps 13-16) spermatids, was decreased to 44.4% of the values measured in the wild-type animals. The incidence of germ cell apoptosis increased 3.8-fold in the transgenic animals and was associated with a marked loss of germ cells. Electron microscopy of the testes further revealed large vacuoles in the Sertoli cell cytoplasm and dilations of the intracellular spaces between adjacent Sertoli cells, spermatid malformations, and increased germ cell apoptosis in the transgenic animals. There was no evidence of Sertoli cell death either by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay or electron microscopy. Leydig cell ultrastructure, cell size and numbers, and plasma levels of testosterone were not different between normal and the transgenic animals. Collectively, these results support the critical role of Bcl-2 in male germ cell development and are consistent with the gender-specific role of the Bcl-2 family members in reproduction.

The emission characteristics of a small D.I. diesel engine using biodiesel blended fuels.

Biodiesel and biodiesel blends provide low emissions without modification on the fuel system of conventional diesel engines. This study aims to develop a new domestic biodiesel production procedure which makes use of waste fryer vegetable oil by transesterification method, and further investigates the emission characteristics of a small D.I. diesel engine using biodiesel blends and diesel fuels, respectively. The 20/80 and 30/70 blends of biodiesel to diesel fuel are used in this study. The emission characteristics include smoke emissions, gaseous emissions (CO, HC, NOx and SO2), particle size distributions and number concentrations at a variety of steady state engine speed points. We have found that diesel engine fueled with biodiesel blends emits more PM2 particle number concentrations than those with diesel fuel, and PM2 number concentration increases as biodiesel concentration increases. As for the smoke and gaseous emissions, such as CO, HC, NOx and SO2, the results favored biodiesel blends.

XXY male mice: an experimental model for Klinefelter syndrome.

Klinefelter syndrome (47,XXY) is the most common sex chromosome aneuploidy in men. Thus, it is important to establish an experimental animal model to explore its underlying molecular mechanisms. Mice with a 41,XXY karyotype were produced by mating wild-type male mice with chimeric female mice carrying male embryonic stem cells. The objectives of the present study were to characterize the testicular phenotype of adult XXY mice and to examine the ontogeny of loss of germ cells in juvenile XXY mice. In the first experiment the testicular phenotypes of four adult XXY mice and four littermate controls (40,XY) were studied. XXY mice were identified by either Southern hybridization or karyotyping and were further confirmed by fluorescence in situ hybridization. The results showed that the testis weights of adult XXY mice (0.02 +/- 0.01 g) were dramatically decreased compared with those of the controls (0.11 +/- 0.01 g). Although no significant differences were apparent in plasma testosterone levels, the mean plasma LH and FSH levels were elevated in adult XXY mice compared with controls. The testicular histology of adult XXY mice showed small seminiferous tubules with varying degrees of intraepithelial vacuolization and a complete absence of germ cells. Hypertrophy and hyperplasia of Leydig cells were observed in the interstitium. Electron microscopic examination showed Sertoli cells containing scanty amounts of cytoplasm and irregular nuclei with prominent nucleoli. The junctional region between Sertoli cells appeared normal. In some tubules, nests of apparently degenerating Sertoli cells were found. In the second experiment the ontogeny of germ cell loss in juvenile XXY mice and their littermate controls was studied. Spermatogonia were found and appeared to be morphologically normal in juvenile XXY mice. Progressive loss of germ cells occurred within 10 days after birth. This resulted in the absence of germ cells in the adult XXY mice. We conclude that a progressive loss of germ cells occurring in early postnatal life results in the complete absence of germ cells in adult XXY mice. The XXY mouse provides an experimental model for its human XXY counterpart, Klinefelter syndrome.

Mallory bodies formed in proteasome-depleted hepatocytes: an immunohistochemical study.

Mallory bodies (MBs) are aggregates of proteins, principally cytokeratin proteins found in liver cells. They are also found in a few other cell types such as type II pneumocytes and trophoblasts. Studies on the liver thus far indicate that MBs are derived from hyperphosphorylated, heavily ubiquitinated proteins which have undergone conformational change. The aggregated protein may accumulate because of the failure of the proteasome to remove the altered proteins from the cytoplasm of liver cells. To investigate this possibility, the proteasomes were assessed immunohistochemically in individual liver cells of mice fed a drug which induced MB formation. To accelerate and enhance MB formation, cytochrome P450 2EI knockout mice were used. Proteasomes in individual cells were visualized by immunofluorescence using an antibody to a subunit of the proteasome (P25). The results showed that the groups of liver cells that had formed MBs were often partially depleted of proteasomes. These findings support the possibility that MBs formed as a result of the loss of the proteasome to remove misfolded cytokeratin proteins. Thus MBs may share their pathogenesis with other types of cellular inclusions seen where proteins aggregate in the cytoplasm due to mutation, misfolding, or loss of proteasomes.

Redistribution of Bax is an early step in an apoptotic pathway leading to germ cell death in rats, triggered by mild testicular hyperthermia.

Programmed cell death occurs spontaneously during spermatogenesis and can be induced in a cell- and stage-specific manner by mild testicular hyperthermia. Studies using transgenic mice suggest the involvement of Bcl-2 proteins in regulating germ cell apoptosis. To delineate further the pathways involved, we examined the temporal changes in proapoptotic Bax and antiapoptotic Bcl-2 in rat testes after transient exposure to heat (43 degrees C for 15 min). Germ cell apoptosis, involving exclusively early (I-IV) and late (XII-XIV) stages, was activated within 6 h. Initiation of apoptosis was preceded by a redistribution of Bax from a cytoplasmic to perinuclear localization within 0.5 h of heating as assessed by immunocytochemical methods. In contrast, Bcl-2 is distributed both in the cytoplasm and nucleus in those cell types susceptible to heat-induced apoptosis. Despite the striking redistribution, Bax levels remained unchanged as determined by Western analysis; Bcl-2 levels increased significantly by 6 h after heat exposure. Reverse transcription-polymerase chain reaction analysis indicated no change in either Bax or Bcl-2 mRNA levels in response to heat, suggesting the involvement of post-transcriptional rather than transcriptional mechanisms mediating their activity. The marked subcellular redistribution of Bax prior to activation of apoptosis and the increase in Bcl-2 suggest an involvement of Bcl-2 family members in heat-induced apoptotic death of germ cells.

The strength and functional performance in patients with facioscapulohumeral muscular dystrophy.

Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive myopathy with autosomal dominant inheritance remarkable for its early involvement of facial musculature. The purpose of our study was to assess the rate of strength deterioration, functional condition and performance of activity of daily living of patients with FSHD in Taiwan. Twenty patients diagnosed with FSHD were included in this study. Manual muscle testing (MMT) was used to evaluate muscle strength. The Brooke and Vignos scales were used to assess upper and lower extremity function respectively, and the capability of the activity of daily living was measured by Barthel index. The result of the strength testing was characterized by the presence of a progressive asymmetrical muscular weakness in patients with FSHD. The mean muscular strength of the right extremity was weaker than its left counterparts (p < 0.05) and the shoulder muscle group was the weakest. According to the Brooke functional scale, 20% of our patients were graded as 1, 30% as grade 2, and 50% as grade 3. On the Vignos functional scale, 50% of patients fell into grade 1, 10% in grade 2, and 40% in grades 3-5. Vignos scale was significantly correlated with mean muscle strength (p < 0.05). The average value of Barthel index was 97.8 +/- 4.7. The muscle strength decline in this Taiwanese of FSHD population was more severe in shoulder girdle area. The mean muscle strength of the right extremity was weaker than the left. Most of our patients suffered from mild or moderate physical disability. Finding of these Taiwanese FSHD population is similar to those reported elsewhere in the world.

Long-term effects of triptolide on spermatogenesis, epididymal sperm function, and fertility in male rats.

Prior studies had suggested that triptolide, a diterpene triepoxide isolated from a Chinese medicinal plant, might be an attractive candidate as a post-testicular male contraceptive agent. Despite the promise that triptolide would not affect testis function, nagging concerns remained that a delayed onset of testicular effect might exist. The objectives of this study were to assess the effects of relatively longer treatment duration of triptolide on fertility, spermatogenesis, and epididymal sperm pathophysiology; and to evaluate the reversibility of these effects after the cessation of treatment. Adult male Sprague-Dawley rats were fed daily with either 30% gum acacia as a vehicle control (n = 12) or 100 microg/kg body weight (BW) of triptolide for 82 days (n = 12) followed by a recovery period of up to 14 weeks (n = 6). At the end of the treatment period, all rats treated with triptolide were sterile. Cauda epididymal sperm content decreased by 84.8% and sperm motility was reduced to zero. In addition, virtually all cauda epididymal sperm in the triptolide-treated group exhibited severe structural abnormalities. The most striking changes observed were head-tail separation, premature chromatin decondensation of sperm nuclei, a complete absence of the plasma membrane of the entire middle and principle pieces, disorganization of the mitochondrial sheath, and aggregation of many sperm tails. Longer treatment duration of triptolide also affected spermatogenesis, with marked variability in the response of individual animals. The degree of damage ranged from apparently normal-looking seminiferous tubules to flattened seminiferous epithelium lined by a single layer of cells consisting of Sertoli cells and a few spermatogonia. Affected tubules exhibited intraepithelial vacuoles of varying sizes, multinucleated giant cells, germ cell exfoliation, and tubular atrophy. Recovery occurred as early as 6 weeks after cessation of treatment. By 14 weeks, 4 out of 6 triptolide-treated males were fertile and the females that were impregnated by 3 out of 4 triptolide-treated male rats produced apparently normal litters. These results suggest that triptolide has 2 phenotypic effects on mature and maturing germ cells. The first action appears earlier and manifests mainly in epididymal sperm. The second action presumably is directly on germ cells in testis and causes a variable impairment of spermatogenesis that may not be completely reversible. It is unclear if the earlier effect is a delayed manifestation of subtle testicular injury or post-testicular action.

Posttesticular antifertility action of triptolide in the male rat: evidence for severe impairment of cauda epididymal sperm ultrastructure.

A variety of active diterpene epoxides, including the triptolide (isolated from Tripterygium wilfordii) have been reported to cause infertility in male rats. Previously, we showed that oral administration of triptolide at a dosage of 100 microg/kg per body weight for 70 days completely inhibited fertility in male rats, with little or no demonstrable detrimental effect on spermatogenesis and Leydig cell function as determined by testicular light microscopic appearance and serum and intratesticular testosterone levels. Despite the apparent absence of effects on the testes, cauda epididymal sperm were abnormal, with complete cessation of sperm motility and some reduction in sperm numbers. This study was undertaken to provide additional insight into the subcellular sites and possible mechanisms of action of this compound using ultrastructural analysis of the testes and epididymidis. The most striking effect of triptolide treatment was observed in sperm in the epididymis. In rats rendered infertile with 100 microg/kg per body weight of triptolide daily for 70 days, virtually all cauda epididymal sperm exhibited complete absence of plasma membrane over the entire middle and principal piece, premature decondensation of the nuclei, and disorganization of the mitochondrial sheath with many vacuolated mitochondria. No ultrastructural differences in the epididymal epithelium were observed between control and triptolide-treated rats. The testes appeared to be mildly affected after triptolide treatment but exhibited only subtle ultrastructural defects in the germ cells. The findings of severe impairment of cauda epididymal sperm ultrastructure, along with minimal discernible abnormalities in the fine structural cytology of the testes, further suggest that the site of action of this compound is posttesticular and may be confined to the cauda epididymal sperm. However, we cannot rule out an effect of triptolide that occurs during germ cell maturation but is delayed in its manifestation or triggered at the rete testis and epididymal level.

Strength and functional performance of patients with limb-girdle muscular dystrophy.

This study was design to reach a better understanding of muscle strength, motor function and activity of daily living in patients of limb-girdle muscular dystrophy. Forty-eight patients diagnosed as cases of limb-girdle muscular dystrophy were included in this study. Manual muscle testing was used to evaluate muscle strength. The Brooke and Vignos scales were used to grade upper and lower extremities function, respectively, and the ability of daily living activity was measured by Barthel index. Our patients showed progressive symmetrical limb-girdle muscular weakness. Upon regression analysis we found that mean muscle strength was inversely related to disease duration (years) as follows: mean muscle strength = 0.6052 + (0.6309/disease duration). According to the Brooke functional scale, 89.6% of our patients were graded as 1-3 and 10.4% were graded as 5. On the Vignos functional scale, 79.1% of patients fell into the grades 1-5, one person (2.1%) in grade 6 and 18.8% in grade 9 category. The average Barthel index was 85.3 +/- 20.7. Mean muscle strength was significantly correlated with the average Barthel, Vignos and Brooke functional scales. Our study could offer the strength and functional performance of limb-girdle muscular dystrophy on natural history. The muscle strength declined in Taiwanese patients of limb-girdle muscular dystrophy in a typical pattern. Regression analysis showed that the strength was inversely related to disease duration. These findings demonstrate that most of our patients suffered from mild or moderate physical disability.

Testicular heat exposure enhances the suppression of spermatogenesis by testosterone in rats: the "two-hit" approach to male contraceptive development.

The objectives of the study were to determine stage-specific changes in the kinetics of germ cell apoptosis induced by administration of exogenous testosterone (T) alone and to examine whether addition of a single testicular heat exposure would enhance the induction of germ cell apoptosis and the suppression of spermatogenesis by T. Adult male rats were implanted with 3-cm SILASTIC brand capsules (Dow Corning Corp.) containing T for up to 6 weeks. Intratesticular T levels declined to 2.9% of control values by 1 week and remained suppressed at 2, 3, and 6 weeks after T administration. The incidence of germ cell apoptosis (expressed as numbers per 100 Sertoli cells) was low in control rats (0-9.52). After T treatment, the mean incidence of apoptosis at stages VII-VIII increased significantly by 1 week (21.43 +/-3.33) and showed further increases by 6 weeks (56.30 +/- 7.47); apoptotic rates remained low at early (I-VI) and later (XII-XIV) stages. To test whether the combination of T with a single testicular heat exposure resulted in more complete suppression of spermatogenesis than either treatment alone, four groups of adult rats received one of the following treatments: 1) a subdermal empty polydimethylsilozane implant, 2) exposure to a single testicular heating (43 C for 15 min) applied on day 14, 3) 3-cm T implant, or 4) 3-cm T implant and a single testicular heat exposure (applied on day 14). All animals were killed at the end of 6 weeks. In the heat-treated group, testis weight and testicular sperm counts were decreased to 65.4% and 28.9% of control levels, respectively. The corresponding values in the T-treated group were 49.7% and 24.9% of control levels, respectively. Notably, addition of heat to T further reduced testis weight to 31.1% of control levels and testicular sperm counts to near zero. Histomorphometric analysis showed that all treatments reduced seminiferous tubular diameter and epithelial and luminal volume, with the greatest decrease after combined T and heat treatment. Heat exposure in animals bearing T implants markedly reduced the number of pachytene spermatocytes and round spermatids through apoptosis, resulting in tubules devoid of mature spermatids. Spermatogonia and preleptotene spermatocytes remained unaffected. These results clearly demonstrate that 1) exogenous T reduces intratesticular T and induces apoptosis mainly at stages VII-VIII within 1-6 weeks; 2) the combined treatment of T and heat markedly inhibits spermatogenesis, resulting in near azoospermia within 6 weeks; and 3) meiosis and spermiogenesis are the most vulnerable phases of spermatogenesis in response to T plus heat treatment. These findings suggest that a combination of hormonal treatment such as T and a physical agent (heat exposure) is more effective in suppressing spermatogenesis than either treatment alone. We hypothesize that combination of two antispermatogenic agents ("two hit") working at separate stages of the spermatogenic cycle will lead to greater male contraceptive efficacy.

Knee isokinetic strength and body fat analysis in university students.

Many factors such as anthropometric variables influence strength performance. This study is to determine the relationship between knee isokinetic strength and body composition, and to compare the gender differences. Test-retest reliability had been performed within one week for all measurement methods before the formal study. Fifty-eight 20-25 year-old university students, 32 females and 26 males, participated in this study. Isokinetic strength of the knee flexion and extension was measured at two angular velocities of 60 degrees/sec and 120 degrees/sec. Body composition was measured by bioelectrical impedance analysis (BIA) and skinfold caliper. The others variables including height, body weight, body mass index (BMI), and waist to hip ratio were measured or calculated. The results showed that the intra-class correlation coefficients for isokinetic knee strength were between 0.83 and 0.93, and body composition and anthropometric variables were between 0.83 and 0.98. Isokinetic knee strength was significantly correlated with body height, body weight, BMI, waist and hip ratio and percent of body fat estimated by skinfold caliper (r = -0.56 to 0.64). The correlation between isokinetic strength with percent of body fat estimated by BIA (r = -0.60 to -0.74; p < 0.001) and with fat free mass (r = 0.64 to 0.78; p < 0.001) was even higher. Although male subjects had significantly greater mean values in body height, body weight, waist to hip ratio and isokinetic strength than female subjects, the MANCOVA showed that the effect of gender on knee isokinetic strength would be eliminated when the covariant variable, the percent of body fat measured by BIA and BMI was controlled in the analysis model. In conclusion, knee isokinetic strength was significantly negatively correlated with proportion of fat and positively correlated with fat free mass. The magnitude of strength difference between males and females could be explained by differences in body fat proportion and BMI in this study. Therapist would take the body fat composition, fat free mass, and BMI into consideration in knee muscle strength measurement. Less body fat and higher BMI will contain more fat free mass that produces more muscle strength.