Biomedical subjects

Christina Wang

Publications and source records attributed to Christina Wang.

At least 19 recordsLinked to original sources

PubMed2004

Influence of body mass index and gender on growth hormone (GH) responses to GH-releasing hormone plus arginine and insulin tolerance tests.

The aim of this study is to assess whether gender and body mass index (BMI) should be considered in developing thresholds to define GH deficiency, using GH responses to GHRH + arginine (ARG) stimulation and insulin tolerance test (ITT). Thirty-nine healthy subjects (19 males, 20 females; ages 21-50 yr) underwent GHRH + ARG, and another 27 subjects (19 males, 8 females; ages 20-49 yr) underwent ITT. Peak GH response was significantly higher (P = 0.005) after GHRH + ARG than with ITT, and this difference could not be explained by age, gender, or BMI. Peak GH response was negatively correlated with BMI in both tests (GHRH + ARG, r = -0.76; and ITT, r = -0.65). Peak GH response to GHRH + ARG was higher in females than males (P = 0.004; ratio = 2.4), but it was attenuated after eliminating the influence of BMI (P = 0.13; ratio = 1.6). No significant gender differences were found in peak GH responses to ITT, which could be due to the smaller number of female subjects studied. GH response to GHRH + ARG and ITT stimulation is sensitive to BMI differences and less so to gender differences. A higher BMI is associated with a depressed GH response to both stimulation tests. BMI should therefore be considered as a factor when defining the diagnostic cut-off points in the assessment of GH deficiency, whereas whether gender should be likewise used is inconclusive from this study.

Adult↗

PubMed2004

Experimentally induced androgen depletion accentuates ethnicity-related contrasts in luteinizing hormone secretion in asian and caucasian men.

The basis for ethnicity-related distinctions in gonadotropin secretion are unknown but may have important populational and physiological implications. In male contraceptive trials, exogenous testosterone and progestins suppress spermatogenesis to a greater degree in Asian than Caucasian men. In addition, iv infusion of testosterone inhibits LH release more in Asian than Caucasian volunteers. We test the converse postulate that experimental reduction of androgen-dependent negative feedback by way of the steroidogenic inhibitor combination ketoconazole/dexamethasone will unveil ethnicity-related mechanisms of regulated LH secretion in young men. LH release was monitored by sampling blood every 10 min for 24 h followed by immunoradiometric assay, model-free pulse detection, an entropy (regulatory) statistic, and cosine regression. Statistical comparisons revealed that healthy young Asian and Caucasian men maintain comparable baseline concentrations of LH, testosterone, estradiol, SHBG, and molar testosterone to SHBG ratios. In contrast, the two ethnic groups differ prominently in each of basal, pulsatile, entropic, and 24-h rhythmic LH adaptations to short-term androgen withdrawal. Therefore, we postulate that physiological nonuniformity of sex steroid-dependent negative feedback in particular may contribute to populational diversity in LH regulation.

Adaptation, Physiological↗

PubMed2004

Functional role of caspases in heat-induced testicular germ cell apoptosis.

In the present study, we determined whether a pan caspase inhibitor could prevent or attenuate heat-induced germ cell apoptosis. Groups of five adult (8 wk old) C57BL/6 mice pretreated with vehicle (DMSO) or Quinoline-Val-Asp (Ome)-CH2-O-Ph (Q-VD-OPH), a new generation broad-spectrum caspase inhibitor, were exposed once to local testicular heating (43 degrees C for 15 min) and killed 6 h later. The inhibitor (40 mg/kg body weight) or vehicle was administered intraperitoneally (i.p.) 1 h before local testicular heating. Germ cell apoptosis was detected by TUNEL assay and quantitated as number of apoptotic germ cells per 100 Sertoli cells at stages XI-XII. Compared with controls (16.8 +/- 3.1), mild testicular hyperthermia within 6 h resulted in a marked activation (277.3 +/- 21.6) of germ cell apoptosis, as previously reported by us. Q-VD-OPH at this dose markedly inhibited caspase 3 activation and significantly prevented (by 67.0%) heat-induced germ cell apoptosis. Q-VD-OPH-mediated rescue of germ cells was independent of cytosolic translocation of mitochondrial cytochrome c and DIABLO. Electron microscopy further revealed normal appearance of these rescued cells. Similar protection from heat-induced germ cell apoptosis was also noted after pretreatment with minocycline, a second-generation tetracycline that effectively inhibits cytochrome c release and, in turn, caspase activation. Collectively, the present study emphasizes the role of caspases in heat-induced germ cell apoptosis.

Amino Acid Chloromethyl Ketones↗

PubMed2004

Mitochondria-dependent pathway is involved in heat-induced male germ cell death: lessons from mutant mice.

The signaling events leading to apoptosis can be divided into two major pathways, involving either mitochondria (intrinsic) or death receptors (extrinsic). In a recent study, we have shown the involvement of the mitochondria-dependent apoptotic pathway in heat-induced male germ cell apoptosis in the rat. In additional studies, using the gld (generalized lymphoproliferation disease) and lprcg (lymphoproliferation complementing gld) mice, which harbor loss-of-function mutations in Fas L and Fas, respectively, we have shown that heat-induced germ cell apoptosis is not blocked, thus providing evidence that the Fas signaling system is not required for heat-induced germ cell apoptosis in the testis. In the present study, we have found that the initiation of apoptosis in wild-type mice was preceded by a redistribution of Bax from a cytoplasmic to paranuclear localization in heat-susceptible germ cells. The relocation of Bax is accompanied by sequestration of ultracondensed mitochondria into paranuclear areas of apoptotic germ cells, cytosolic translocation of mitochondrial cytochrome c and DIABLO, and is associated with activation of the initiator caspase 9 and the executioner caspase 3. Similar events were also noted in both gld and lprcg mice. Taken together, these results indicate that the mitochondria-dependent pathway is the key apoptotic pathway for heat-induced male germ cell death in mice.

Animals↗

PubMed2004

Male hormonal contraception.

Male hormonal contraception, based on the suppression of both gonadotropins, follicle-stimulating hormone and luteinizing hormone, resulting in marked decrease in sperm production, is designed for couples in stable relationships where the male partner desires to assume family planning responsibilities using reversible methods. Two large scale, multicenter studies that used testosterone injections as the prototype male hormonal contraceptive demonstrated when azoospermia and/or very severe oligozoospermia were attained, contraceptive efficacy was equivalent to female hormonal methods. Current studies aim to find the androgen alone or androgen plus progestin preparations that are most efficacious, user friendly, and with least potential adverse effects. It is likely that injections or implants of androgens either alone or with progestins will become the first male hormonal contraceptive available within this decade. Further research and development include the use of selective androgen and/or progestin receptor modulators, nonpeptide GnRH antagonists, and agents with local actions on the testis for male contraception.

Clinical Trials as Topic↗

PubMed2004

Androgens and the ageing male.

Serum testosterone levels peak in early adulthood in men and fall progressively with age. Since sex hormone binding globulin increases with age, the unbound forms of testosterone (free and bioavailable testosterone) fall more steeply than total testosterone levels. Serum testosterone levels below the normal range for young healthy adult males provide chemical evidence of androgen deficiency independent of the age of the patient. When accompanied by signs or symptoms that are compatible with androgen deficiency, treatment with testosterone should be considered in older men without evidence of prostate or breast cancer. While such therapy for younger hypogonadal men has shown benefit on libido, mood, muscle mass, muscle strength, bone mineral density and haematocrit, similar benefits in older men have not been as adequately assessed. While there is no convincing evidence that testosterone treatment in older men will increase the risk of cardiovascular or prostate cancer, long-term, well-controlled studies are lacking and needed. Treatment options for older men include injectable, transdermal and transbuccal testosterone preparations.

Adipose Tissue↗

PubMed2004

The role of carnitine in the male reproductive system.

Carnitine is highly concentrated in the epididymis and spermatozoa, where it may serve as an intramitochondrial vehicle for the acyl group, which in the form of acyl CoA acts as a substrate for the oxidation process producing energy for sperm respiration and motility. To date, studies in rodents and humans suggest that sperm count, motility, and maturation are related to epididymal free carnitine concentrations. Moreover, supplementation with carnitine improves sperm quality and/or quantity in testes of mice exposed to physical insults, such as heat and X-irradiation, and in men with idiopathic oligoasthenospermia. These benefits may be due to increased mitochondrial fatty acid oxidation resulting in improvement in motility of epididymal sperm. The antiapoptotic effect(s) of carnitine in the testes may also contribute, but this remains speculative and requires further investigation. Research to uncover the many characteristics and mechanisms of action of carnitine in somatic and germ cells may provide insights into the pathophysiology of germ cell apoptosis, the prevention of germ cell death, and possibly specific therapy of some forms of infertility. Further well-controlled, carefully designed, larger-scale studies are necessary and desirable before widespread clinical use as an infertility therapy can be contemplated.

Animals↗

PubMed2004

Measurement of total serum testosterone in adult men: comparison of current laboratory methods versus liquid chromatography-tandem mass spectrometry.

The diagnosis of male hypogonadism requires the demonstration of a low serum testosterone (T) level. We examined serum T levels in pedigreed samples taken from 62 eugonadal and 60 hypogonadal males by four commonly used automated immunoassay instruments (Roche Elecsys, Bayer Centaur, Ortho Vitros ECi and DPC Immulite 2000) and two manual immunoassay methods (DPC-RIA, a coated tube commercial kit, and HUMC-RIA, a research laboratory assay) and compared results with measurements performed by liquid chromatography-tandem mass spectrometry (LC-MSMS). Deming's regression analyses comparing each of the test results with LC-MSMS showed slopes that were between 0.881 and 1.217. The interclass correlation coefficients were between 0.92 and 0.97 for all methods. Compared with the serum T concentrations measured by LC-MSMS, the DPC Immulite results were biased toward lower values (mean difference, -90 +/- 9 ng/dl) whereas the Bayer Centaur data were biased toward higher values (mean difference, +99 +/- 11 ng/dl) over a wide range of serum T levels. At low serum T concentrations (<100 ng/dl or 3.47 nmol/liter), HUMC-RIA overestimated serum T, Ortho Vitros ECi underestimated the serum T concentration, whereas the other two methods (DPC-RIA and Roche Elecsys) showed differences in both directions compared with LC-MSMS. Over 60% of the samples (with T levels within the adult male range) measured by most automated and manual methods were within +/- 20% of those reported by LC-MSMS. These immunoassays are capable of distinguishing eugonadal from hypogonadal males if adult male reference ranges have been established in each individual laboratory. The lack of precision and accuracy, together with bias of the immunoassay methods at low serum T concentrations, suggests that the current methods cannot be used to accurately measure T in females or serum from prepubertal subjects.

Adult↗

PubMed2004

Testosterone metabolic clearance and production rates determined by stable isotope dilution/tandem mass spectrometry in normal men: influence of ethnicity and age.

The metabolic clearance rate (MCRT) and production rate (PRT) of testosterone (T) were measured using constant infusion of trideuterated (d3) T and quantitating serum d3T by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Serum unlabeled T (d0T) was measured by LC-MS-MS, and serum total T (d3T + d0T) was measured by RIA. Mean MCRR (measured by LC-MS-MS) in young white men (1272 +/- 168 liters/d) was not significantly different from young Asian men (1070 +/- 166 liters/d). Mean PRT was also not significantly different between the two ethnic groups (whites, 9.11 +/- 1.11 mg/d; Asians, 7.22 +/- 1.15 mg/d; P = 0.19 using d0T data). Both the mean MCRR (812 +/- 64 liters/d; P < 0.01) and the PRT (3.88 +/- 0.27 mg/d; P < 0.001) were significantly lower in middle-aged white men when compared with their younger counterparts. The mean MCRR and PRR calculated using serum total T or d0T data showed a diurnal variation, with levels at midday significantly higher than those measured in the evening in the young (MCRT, P < 0.01; PRT, P < 0.001) and to a lesser extent in the older men (MCRT, P < 0.05; PRT, P < 0.05 using total T and P < 0.001 using d0T data). We conclude that using LC-MS-MS to detect d3T in serum after constant infusion of stable isotope-labeled T allows the measurements of MCRT and PRT, which can be used to study androgen metabolism repeatedly after physiological or pharmacological interventions.

Adult↗

PubMed2004

New testosterone buccal system (Striant) delivers physiological testosterone levels: pharmacokinetics study in hypogonadal men.

A new mucoadhesive testosterone buccal system (Striant), 30 mg testosterone (T), was applied twice daily in 82 hypogonadal men for 3 months. Serum T, free T, and 5alpha-dihydrotestosterone were measured during this period. T pharmacokinetics were determined from the data obtained during a 24-h sampling at wk 12. Physiological mean serum T concentrations were steady and consistently maintained. The mean percentage of time over a 24-h period that total serum T concentrations were above the lower limit of adult male range was 80.1%. During treatment, mean serum 5alpha-dihydrotestosterone, free T, and estradiol concentrations paralleled serum T. T pharmacokinetics were not significantly affected by body mass index, age, food or beverage, gum abnormalities, or medications known to cause dry mouth. Gum-related adverse events occurred in 16.3% of subjects. Except for three subjects, the gum adverse effects occurred early during treatment, did not cause interruption of treatment, and resolved rapidly and completely. The T buccal system is a novel T formulation that offers a safe, effective, and convenient alternative to existing formulations for physiological T replacement therapy in hypogonadal men.

Adult↗

PubMed2004

Long-term testosterone gel (AndroGel) treatment maintains beneficial effects on sexual function and mood, lean and fat mass, and bone mineral density in hypogonadal men.

Transdermal testosterone (T) delivery represents an effective alternative to injectable androgens. We studied 163 hypogonadal men who applied 5, 7.5, or 10 g AndroGel (T gel) 1% CIII per day for up to 42 months. Efficacy data were presented in 123 subjects considered evaluable. Continuous AndroGel treatment normalized mean serum T and free T levels. Mean serum 5alpha-dihydrotestosterone concentrations and 5alpha-dihydrotestosterone/T ratio slightly increased, mean serum estradiol/T ratio doubled, and mean serum FSH and LH levels were suppressed by T replacement. Sexual function and mood parameters improved rapidly and were maintained throughout T treatment. Lean body mass increased (P = 0.0001) and fat mass decreased (P = 0.0001), and these changes were maintained with treatment but were not accompanied by significant increases in muscle strength. Increases in serum bone markers suggestive of increased bone formation were followed by gradual and progressive increases in bone mineral density more in the spine (P = 0.0001) than the hip (P = 0.0004). Mild local skin irritation occurred in 12 subjects, resulting in discontinuation in only one subject. Except for the anticipated increase in hematocrit and hemoglobin, there were no clinically significant changes in blood counts or biochemistry. In three subjects with elevated serum prostate-specific antigen, prostate biopsies showed cancer. We conclude that continued application of AndroGel resulted in beneficial effects similar to those with injectables and other transdermal preparations. This study was neither placebo controlled nor powered to determine the effects of T treatment on prostate cancer risk. Thus, monitoring for prostatic disease and assessment for erythrocytosis are strongly advised to reduce the risk of adverse events with T treatment of hypogonadal men.

Adolescent↗

PubMed2003

Deciphering the pathways of germ cell apoptosis in the testis.

A growing body of evidence demonstrates that germ cell death both spontaneous (during normal spermatogenesis) and that induced by suppression of hormonal support or increased scrotal temperature occurs via apoptosis. The mechanisms by which these proapoptotic stimuli activate germ cell apoptosis are not well understood. In order to provide some insight, here we report the key molecular components of the effector pathways leading to caspase activation and increased germ cells apoptosis triggered by mildly increased scrotal temperature. Short-term exposure (43 degrees C for 15 min) of the testis to mild heat results, within 6h, in stage- and cell-specific activation of germ cell apoptosis in rats. Initiation of apoptosis was preceded by a redistribution of Bax from a cytoplasmic to paranuclear localization in heat-susceptible germ cells. Such relocation of Bax is further accompanied by sequestration of mitochondria and endoplasmic reticulum (ER) into paranuclear areas, cytosolic translocation of cytochrome c and is associated with activation of the initiator caspase 9 and the executioner caspases 3, 6, and 7, and cleavage of PARP. Furthermore, Bax is co-localized with ER in the susceptible germ cells as assessed by combined two-photon and confocal microscopy and Western blot analyses of fractionated testicular lysates. In additional studies, using gld and lpr(cg) mice, which harbor loss-of-function mutations in Fas-ligand (FasL) and Fas, respectively, we demonstrated that heat-induced germ cell apoptosis is not blocked, thus providing further evidence that the Fas signaling system is dispensable for heat-induced germ cell apoptosis in the testis. Taken together, these results demonstrate that the mitochondria- and possibly also ER-dependent pathways are the key apoptotic pathways for heat induced germ cell death in the testis.

Animals↗

PubMed2003

Functional role of inducible nitric oxide synthase in the induction of male germ cell apoptosis, regulation of sperm number, and determination of testes size: evidence from null mutant mice.

Inducible nitric oxide synthase (iNOS) through its product, nitric oxide (NO), may contribute to the induction of germ cell apoptosis. Using adult iNOS-deficient mice, we characterized the reproductive hormonal profile and the testicular phenotype. Although there was no difference in body weight, mean testis weights in mutant mice were 30.77% higher, and testicular sperm count was 65.51% higher than control animals. No significant differences were apparent in plasma LH, FSH, and testosterone levels between these mice. Compared with wild-type mice, histomorphometric analysis showed that the mutant mice had a 39.63% increase in the number of pachytene spermatocytes and 33.79% in round spermatids, with no apparent changes in the number of preleptotene spermatocytes and spermatogonia. The incidence of spontaneous germ cell apoptosis detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay was lower at stages I-IV and XI-XII of iNOS-mutant mice compared with wild-type animals. The rate of germ cell proliferation estimated by quantitative assessment of the bromodeoxyuridine labeled preleptotene spermatocytes showed no significant change between wild-type and iNOS-deficient mice. When applying testicular warming (43 C for 15 min) to mice, the rate of germ cell apoptosis was elevated predominantly at early (I-IV) and late (XI-XII) stages, and less during stages V-VI, VII-VIII, and IX-X at 2 and 6 h after heat exposure in the wild-type mice. In contrast, the rate of apoptosis in mutant mice was markedly decreased at early and late stages 2 and 6 h after heat exposure. Pachytene spermatocytes and early round spermatids were most susceptible to heat-induced apoptosis in both mutant and control animals. Our studies demonstrate that: 1) deficiency of iNOS results in failure to eliminate a small portion of pachytene spermatocytes and round spermatids by apoptosis, resulting in a remarkable increase in testis weight and sperm output; 2) deficiency of iNOS confers partial resistance to heat-induced germ cell apoptosis. These experiments suggest that iNOS plays a physiological role in regulation of germ cell number and in determining testicular size.

Animals↗

PubMed2003

Key apoptotic pathways for heat-induced programmed germ cell death in the testis.

Short-term exposure (43 C for 15 min) of the rat testis to mild heat results within 6 h in stage- and cell-specific activation of germ cell apoptosis. Initiation of apoptosis was preceded by a redistribution of Bax from a cytoplasmic to paranuclear localization in heat-susceptible germ cells. Here we show that the relocation of Bax is accompanied by cytosolic translocation of cytochrome c and is associated with activation of the initiator caspase 9 and the executioner caspases 3, 6, and 7 and cleavage of poly(ADP) ribose polymerase. Furthermore, early in apoptosis, a significant amount of Bax also accumulates in endoplasmic reticulum, as assessed by Western blot analyses of fractionated testicular lysates. In additional studies using the FasL-defective gld mice, we have shown that heat-induced germ cell apoptosis is not blocked, thus providing evidence that the Fas signaling system may be dispensable for heat-induced germ cell apoptosis in the testis. Taken together, these results demonstrate that the mitochondria- and possibly also endoplasmic reticulum-dependent pathways are the key apoptotic pathways for heat-induced germ cell death in the testis.

Animals↗

PubMed2003

Geographic differences in semen quality of fertile U.S. males.

Although geographic variation in semen quality has been reported, this is the first study in the United States to compare semen quality among study centers using standardized methods and strict quality control. We evaluated semen specimens from partners of 512 pregnant women recruited through prenatal clinics in four U.S. cities during 1999-2001; 91% of men provided two specimens. Sperm concentration, semen volume, and motility were determined at the centers, and morphology was assessed at a central laboratory. Study protocols were identical across centers, and quality control was rigorously maintained. Sperm concentration was significantly lower in Columbia, Missouri, than in New York, New York; Minneapolis, Minnesota; and Los Angeles, California. Mean counts were 58.7, 102.9, 98.6, and 80.8 X 10(6)/mL (medians 53.5, 88.5, 81.8, and 64.8 X 10(6)/mL) in Missouri, New York, Minnesota, and California, respectively. The total number of motile sperm was also lower in Missouri than in other centers: 113, 196, 201, and 162 X 10(6) in Missouri, New York, Minnesota, and California, respectively. Semen volume and the percent morphologically normal sperm did not differ appreciably among centers. These between-center differences remained significant in multivariate models that controlled for abstinence time, semen analysis time, age, race, smoking, history of sexually transmitted disease, and recent fever (all p-values < 0.01). Confounding factors and differences in study methods are unlikely to account for the lower semen quality seen in this mid-Missouri population. These data suggest that sperm concentration and motility may be reduced in semirural and agricultural areas relative to more urban and less agriculturally exposed areas.

Adult↗

PubMed2003

Semen quality in relation to biomarkers of pesticide exposure.

We previously reported reduced sperm concentration and motility in fertile men in a U.S. agrarian area (Columbia, MO) relative to men from U.S. urban centers (Minneapolis, MN; Los Angeles, CA; New York, NY). In the present study we address the hypothesis that pesticides currently used in agriculture in the Midwest contributed to these differences in semen quality. We selected men in whom all semen parameters (concentration, percentage sperm with normal morphology, and percentage motile sperm) were low (cases) and men in whom all semen parameters were within normal limits (controls) within Missouri and Minnesota (sample sizes of 50 and 36, respectively) and measured metabolites of eight current-use pesticides in urine samples provided at the time of semen collection. All pesticide analyses were conducted blind with respect to center and case-control status. Pesticide metabolite levels were elevated in Missouri cases, compared with controls, for the herbicides alachlor and atrazine and for the insecticide diazinon [2-isopropoxy-4-methyl-pyrimidinol (IMPY)]; for Wilcoxon rank test, p = 0.0007, 0.012, and 0.0004 for alachlor, atrazine, and IMPY, respectively. Men from Missouri with high levels of alachlor or IMPY were significantly more likely to be cases than were men with low levels [odds ratios (ORs) = 30.0 and 16.7 for alachlor and IMPY, respectively], as were men with atrazine levels higher than the limit of detection (OR = 11.3). The herbicides 2,4-D (2,4-dichlorophenoxyacetic acid) and metolachlor were also associated with poor semen quality in some analyses, whereas acetochlor levels were lower in cases than in controls (p = 0.04). No significant associations were seen for any pesticides within Minnesota, where levels of agricultural pesticides were low, or for the insect repellent DEET (N,N-diethyl-m-toluamide) or the malathion metabolite malathion dicarboxylic acid. These associations between current-use pesticides and reduced semen quality suggest that agricultural chemicals may have contributed to the reduction in semen quality in fertile men from mid-Missouri we reported previously.

Adult↗

PubMed2003

Endonasal transsphenoidal approach for pituitary adenomas and other sellar lesions: an assessment of efficacy, safety, and patient impressions.

OBJECT: The direct endonasal approach performed with the aid of an operating microscope for removal of pituitary tumors has the potential advantage over the traditional sublabial route of minimizing postoperative rhinological complications, yet maintaining a high degree of efficacy and safety. To assess the effectiveness of this procedure, tumor remission rates and surgical complications were documented, and patients' postoperative complaints were recorded using a questionnaire. METHODS: One hundred consecutive patients underwent 109 endonasal operations for tumor removal. At a median follow-up period of 16 months (range 3-45 months), surgical remission rates were as follows: in 40 patients with endocrine-inactive macroadenomas, 95% for noninvasive and 40% for invasive tumors; in the 20 patients with prolactinomas, 75% for prolactinomas with an initial prolactin (PRL) level lower than 200 ng/ml, 33% for those with a PRL level between 200 and 600 ng/ml, and 0% for those with a PRL level higher than 1400 ng/ml; in the 15 patients with Cushing disease, 73% for microadenomas and 25% for macroadenomas; in the 10 patients with acromegaly, 75% for microadenomas and 50% for macroadenomas; in the five patients with Rathke cleft cysts, 80%; and in the five patients with craniopharyngiomas, 40%. There were seven major surgical complications and no operative deaths. Among the 78 patients who completed questionnaires (response rate 89%), the most common complaints concerned nasal packing (39%), removal of packing (36%), and mouth breathing (35%). At 3 months or longer after surgery, patients quantified sinonasal problems as follows: for facial pain, no problem in 83% and severe difficulty in 4%; for nasal congestion, no problem in 74%, and severe difficulty in 3%; for decreased nasal airflow, no problem in 77% and severe difficulty in 4%; for decreased sense of smell, no problem in 73% and severe difficulty in 4%; and for upper-lip numbness, no problem in 87% and severe difficulty in 1%. Twelve (86%) of 14 patients who had undergone sublabial surgery previously preferred the endonasal approach in terms of pain and ease of recovery. CONCLUSIONS: The direct endonasal route for pituitary tumor removal has efficacy and complication rates comparable to those of the sublabial route. Patients generally recover rapidly from this minimally invasive procedure and have no or minimal sinonasal complaints. For patients requiring a repeated operation, the endonasal route appears to be less painful and easier to recover from than the sublabial route. Given the minimal nasal mucosal dissection required and the frequent patient complaints related to nasal packing, use of packing is no longer used for this procedure.

Adenoma↗

PubMed2002

Male contraception.

Currently approved male-directed contraceptive methods include condoms and vas occlusion. Vas occlusion is very effective but is intended to be non-reversible. Condoms have a relatively high failure rate, at least partially due to compliance problems and are not accepted by many couples. The only other male-oriented methods in clinical trials utilize the administration of testosterone alone or its combination with another gonadotropin-suppressing agent such as a progestin or a gonadotropin-releasing hormone antagonist. Studies published in the 1990s demonstrated that a testosterone-containing hormonal contraceptive method suppressed spermatogenesis to azoospermia in most men and severe oligozoospermia in the remaining. The contraceptive efficacy after treatment with testosterone alone was comparable to that of female hormonal methods. Having proven that reversible male contraception is a reality, present trials are attempting to identify the best androgen delivery system and the most effective androgen plus progestin preparation. It is likely that the first marketed male hormonal contraceptive method will be a long-acting (injectable or implant) combination of an androgen plus a progestin. Research is continuing to identify other target areas for male contraceptive development, including agents with post-testicular and epididymal sites of action.

Androgen Antagonists↗