Efficacy and acceptability of testosterone implants, alone or in combination with a 5alpha-reductase inhibitor, for male hormonal contraception

Testosterone (T) treatment suppresses serum gonadotropins and reduces sperm output sufficiently for contraceptive efficacy in approximately 70% of Caucasian men. In the remaining 30% of men, an increase in 5alpha-reductase activity may maintain testicular androgen activity, thus accounting for the failure of sperm suppression. The form of T therapy is a major consideration in the safety and acceptability of T-based contraception. As compared to T ester injections, T implants provide a more physiological serum T profile and fewer side effects, but have not yet been used in contraceptive efficacy studies. We have used T implants (800-1200 mg every 3 months) in 29 normal men for 3-16 months. T implants produced long-term suppression of sperm densities below 1 million/mL in approximately 70% of men without significant androgenic side effects. No pregnancies occurred in 214 months of exposure. In 16 men failing to suppress within 3 months of T 800 mg, no evidence of enhanced spermatogenic suppression was seen with the co-administration of the type 2 5alpha-reductase inhibitor, finasteride, for 3 months when compared to placebo. We conclude that: 1) T implants provide adequate spermatogenic suppression in approximately 70% of Caucasian men, a rate comparable to intramuscular T injections but with minimal side effects; and, 2) the inclusion of a type 2 5alpha-reductase inhibitor does not enhance spermatogenic suppression.

Sertoli cell ectoplasmic specializations in the seminiferous epithelium of the testosterone-suppressed adult rat

The Sertoli cell ectoplasmic specialization is a unique junctional structure involved in the interaction between elongating spermatids and Sertoli cells. We have previously shown that suppression of testicular testosterone in adult rats by low-dose testosterone and estradiol (TE) treatment causes the premature detachment of step 8 round spermatids from the Sertoli cell. Because these detaching round spermatids would normally associate with the Sertoli cell via the ectoplasmic specialization, we hypothesized that ectoplasmic specializations would be absent in the seminiferous epithelium of TE-treated rats, and the lack of this junction would cause round spermatids to detach. In this study, we investigated Sertoli cell ectoplasmic specializations in normal and TE-treated rat testis using electron microscopy and localization of known ectoplasmic specialization-associated proteins (espin, actin, and vinculin) by immunocytochemistry and confocal microscopy. In TE-treated rats where round spermatid detachment was occurring, ectoplasmic specializations of normal morphology were observed opposite the remaining step 8 spermatids in the epithelium and, importantly, in the adluminal Sertoli cell cytoplasm during and after round spermatid detachment. When higher doses of testosterone were administered to promote the reattachment of all step 8 round spermatids, newly elongating spermatids associated with ectoplasmic specialization proteins within 2 days. We concluded that the Sertoli cell ectoplasmic specialization structure is qualitatively normal in TE-treated rats, and thus the absence of this structure is unlikely to be the cause of round spermatid detachment. We suggest that defects in adhesion molecules between round spermatids and Sertoli cells are likely to be involved in the testosterone-dependent detachment of round spermatids from the seminiferous epithelium.

The roles of activins, inhibins and estrogen in early committed follicles

The hypothesis that activin and inhibin are autocrine/paracrine mediators of ovarian folliculogenesis has a solid basis. In mouse and rat models, granulosa cells (GC) of committed follicles express mRNA and protein for the activin/inhibin subunits and mRNA for the activin receptors (type I and II). Dimeric inhibin-A and -B are produced by postnatal ovarian cell dispersates and (GC) in culture. Similar levels of inhibin-A and -B are produced by postnatal ovarian cells, but thereafter as the ovary develops, inhibin-A becomes the predominant form. Activin was more effective than transforming growth factor-beta (TGF-beta) in enhancing follicle stimulating hormone (FSH)-stimulated inhibin production by ovarian cells. Evidence for a local regulatory role of estrogen in the ovary is also accumulating. Murine models of estrogen receptor (ERalpha or ERbeta) disruption produce mice with abnormal ovarian phenotypes. Female mice, which lack the capacity to produce estrogen (ArKO mice), have arrested folliculogenesis, no corpora lutea, elevated levels of luteinising hormone (LH), FSH and testosterone and are infertile. These data are consistent with autocrine/paracrine actions of activin in the early growth of committed follicles and estrogen in follicular maturation.

Prefrontal and medial temporal correlates of repetitive violence to self and others

BACKGROUND

The neurobiological basis for violence in humans is poorly understood, yet violent behavior (to self or others) is associated with large social and healthcare costs in some groups of patients (e.g., the mentally retarded). The prefrontal cortex and amygdalo-hippocampal complex (AHC) are implicated in the control aggression, therefore we examined the neural integrity of these regions in violent patients with mild mental retardation and nonviolent control subjects.

METHODS

We used (1)H-magnetic resonance spectroscopy (MRS) to measure 1) concentrations and ratios of N-acetyl aspartate (NAA), creatine phosphocreatine (Cr+PCr), and choline-related compounds (Cho) in prefrontal lobe of 10 violent inpatients and 8 control subjects; 2) ratios of NAA, Cr+PCr, and Cho in the AHC of 13 inpatients and 14 control subjects; and 3) frequency and severity of violence in patients.

RESULTS

Compared to control subjects, violent patients had significantly (p <.05, analysis of covariance-age and IQ as confounding covariates) lower prefrontal concentrations of NAA and Cr+PCr, and a lower ratio of NAA/Cr+PCr in the AHC. Within the violent patient group, frequency of observed violence to others correlated significantly with prefrontal lobe NAA concentration (r = -0.72, p <.05).

CONCLUSIONS

NAA concentration indicates neuronal density, and Cr+PCr concentration high-energy phosphate metabolism. Our findings suggest that violent patients with mild mental retardation have reduced neuronal density, and abnormal phosphate metabolism in prefrontal lobe and AHC compared to nonviolent control subjects. Further studies are needed, however, to determine if these findings are regionally specific, or generalize to other groups of violent individuals.

Confluent choroidal infiltrates with sarcoidosis

PURPOSE

To report the occurrence of confluent plaquelike choroidal infiltrates in four patients with sarcoidosis.

METHODS

The medical records of patients with choroidal plaquelike infiltrates and presumed systemic sarcoidosis seen in the Mayo Clinic were reviewed.

RESULTS

The cohort included four patients with confluent plaquelike choroidal infiltrates and systemic sarcoidosis. The most common ophthalmic symptom experienced by the patients was mild blurring of vision. The salient ophthalmic findings were choroidal infiltrates generally unaccompanied by other features frequently seen with sarcoidosis such as periphlebitis, multiple small yellowish choroidal infiltrations, vitreous cellular reaction, and granulomatous anterior uveitis. The choroidal lesions were confluent, yellowish, irregularly thickened infiltrates that frequently radiated peripherally from a peripapillary location in an ameboidlike pattern. Fluorescein angiography demonstrated early hypofluorescence and progressive patchy hyperfluorescence with late staining of the active lesions. Treatment with either systemic or subconjunctival steroids was associated with improvement in vision and partial resolution of the choroidal lesions. In two patients some of the lesions resolved spontaneously and became replaced by areas of chorioretinal atrophy.

CONCLUSION

Plaquelike yellowish choroidal infiltrates associated with systemic sarcoidosis may occur in eyes remarkably free of other signs of inflammation. The infiltrates tend to radiate from the region of the optic nerve in a confluent ameboidlike pattern. They generally respond to corticosteroids and may be the first recognized manifestation of systemic sarcoidosis.

Presumed rhegmatogenous retinal detachment in patients with retinoblastoma

PURPOSE

To review the characteristics, treatment, and outcome of presumed rhegmatogenous retinal detachment (RD) in patients with retinoblastoma.

METHODS

Descriptive consecutive case series study from 1970 to 1996.

RESULTS

Of 45 eyes with retinoblastoma that received various modalities of eye-sparing treatment and adequate follow-up, five developed presumed rhegmatogenous RD after treatment. All five eyes had previous treatment with external beam radiation, four of which also had been treated with cryotherapy. To minimize the potential spread of the malignancy intraoperatively, long disease-free intervals were ensured before scleral buckling surgeries were performed, and special care was taken during subretinal fluid drainage. The RDs were totally reattached in three eyes and partially reattached in the other two.

CONCLUSION

Presumed rhegmatogenous RD may occur after external beam radiation or cryotherapy for retinoblastoma. It poses special challenges in management.

Early follicular phase serum FSH as a function of age: the roles of inhibin B, inhibin A and estradiol

OBJECTIVE

Reproductive aging in regularly cycling normal women is characterized by a gradual decline in ovarian follicle number and a progressive increase in serum follicle stimulating hormone (FSH), particularly over the age of 40 years. The lack of any consistent decrease in circulating estradiol and progesterone has led to the hypothesis that the FSH increase results from decreasing ovarian inhibin production. The aim of this study was to investigate the relationship between serum inhibins A and B, FSH and estradiol in normal women between the ages of 20 and 50 years.

DESIGN AND PATIENTS

Serum from 66 regularly cycling subjects, aged 20-50 years, was collected on days 3-5 of the menstrual cycle for this cross-sectional study.

MEASUREMENTS

Serum inhibin A and inhibin B levels were measured by specific enzyme-linked immunosorbent assays (ELISAs). Alpha subunit forms were determined by an immunofluorometric assay which detects all known monomeric and dimeric forms of inhibin A and inhibin B and free alpha subunit. FSH and estradiol levels were measured by immunoassay. Data were log transformed before analysis.

RESULTS

Serum FSH, inhibin A and estradiol, but not inhibin B, were positively correlated (p < 0.05-p < 0.001) with age between years 20 and 50. Between 40 and 50 years, serum FSH was negatively correlated with inhibin B (r = -0.61, p < 0.001) and alpha subunit forms (r = -0.47, p < 0.05) and with estradiol (r = -0.39, p < 0.05), but not with inhibin A (r = -0.21, not significant). When log(FSH) was modelled as a function of log(inhibin B) and log(estradiol) with age fitted as a covariate, inhibin B only was a significant independent predictor of FSH (beta = -0.30, p < 0.01). Using purified inhibin A and B standards for the three assays, which were calibrated in terms of their alpha subunit content, serum inhibin A levels were 10-15% of those of inhibin B, with inhibin A + B levels being 22% of total alpha subunit levels. No significant correlation was observed between total inhibin alpha subunit and its dimers. The free alpha subunit, as determined from the difference in levels of total alpha subunit and inhibin A + B, remained relatively unchanged with age, suggesting that it is not differentially regulated.

CONCLUSIONS

This study shows that, during the early follicular phase, FSH, inhibin A and estradiol but not inhibin B increase with age. Some of the increase in inhibin A and estradiol may be the result of accelerated follicular development with increasing age. Serum inhibin B and estradiol but not inhibin A are inversely correlated with FSH between ages 40 and 50, but only inhibin B is a significant independent predictor of FSH. This supports the postulate that inhibin B is the main form of inhibin regulating FSH at this stage of the menstrual cycle. During the early follicular phase, serum levels of inhibin A are presumably too low to play a significant physiological role or are less active.

Relationship between serum inhibin A and B and ovarian follicle development after a daily fixed dose administration of recombinant follicle-stimulating hormone

The aim of this study was to investigate the relationship of serum inhibin A and inhibin B to ovarian follicular development in women undergoing pituitary down-regulation and ovarian stimulation with a fixed daily dose of recombinant human FSH in an in vitro fertilization program. Thirty-eight patients were treated randomly with either 100 or 200 IU/day recombinant human FSH (Puregon) for a period of 9-14 days. Serum FSH, inhibin A, inhibin B, 17beta-estradiol, and follicular size and number were determined before FSH treatment and every second day from days 4-6 throughout FSH treatment. Serum FSH increased in a dose-related manner to reach a maximum by days 4-6 and remained unchanged over the duration of treatment. Serum inhibin A and 17beta-estradiol also increased with increasing FSH dose and continued to rise throughout the FSH treatment period. By contrast, serum inhibin B was increased by days 4-6 at both doses of FSH to reach a maximum by days 7-8, remaining unchanged thereafter. Serum inhibin B and, to a lesser extent, inhibin A correlated significantly with the number of oocytes retrieved even when assessed early (days 4-6) in the treatment period (inhibin B vs. number of oocytes: r = 0.89; P < 0.001; inhibin A vs. number of oocytes: r = 0.61; P < 0.05). Serum inhibin A, inhibin B, and 17beta-estradiol were weakly correlated with the number of follicles less than 11 mm when assessed on a daily basis; stronger correlations were observed with the greater than 11-mm follicles during the late stages of treatment. It is concluded that serum inhibin B levels determined during the early stages (e.g. days 4-6) of fixed dose FSH treatment provide an early indicator of the number of recruited follicles that are destined to form mature oocytes. In this context, serum inhibin B may be of predictive value in monitoring ovarian hyperstimulation treatment for in vitro fertilization.

FSH immunoneutralization acutely impairs spermatogonial development in normal adult rats

Follicle-stimulating hormone (FSH) plays an important part in testicular development. Its role in the regulation of spermatogenesis in the adult, however, remains controversial. This study aimed to explore the role of FSH in the maintenance of adult rat spermatogenesis by using immunoneutralization to selectively withdraw FSH action for periods of up to 8.5 days and then assessing the outcome by quantification of germ cell number. Adult rats received either an ovine polyclonal rat FSH antibody (FSHAb, 2 mg/kg subcutaneous daily-a dosage known to neutralize >90% of FSH in serum) for 2, 4, 7, or 8.5 days or a control sheep immunoglobulin (ConAb, 2 mg/kg) for 8.5 days. Testes were perfusion fixed, and germ cell numbers per testis were quantified using the optical disector (sic) stereological method. The percentage of seminiferous tubules displaying apoptotic cells was determined by the in situ end labeling method (TUNEL). FSHAb treatment for 4, 7, or 8.5 days significantly reduced the number of type A/intermediate spermatogonia (approximately 74% of control values) associated with stages I-IV. Similar reductions were seen in type B spermatogonial and preleptotene spermatocyte numbers after 8.5 days of FSHAb treatment (approximately 69% of control values; P < 0.05). Decreases (P < 0.05) in the numbers of pachytene spermatocytes in stages I-III and VIII, round spermatids in stages I-III, VII, and VIII (approximately 70% of control values), and step 19 elongated spermatids in stage VII (51% of control values) were achieved after 8.5 days of FSHAb treatment. Compared with control, FSHAb treatment increased the percentage of stage XIV-III tubules containing TUNEL-positive cells by about twofold after 7 days of FSHAb treatment (P < 0.05). This study supports a role for FSH in the maintenance of quantitatively normal adult rat spermatogenesis, specifically by regulating A3 and A4 spermatogonial subtypes. FSH may act on these spermatogonia by enhancing the stage-dependent survival of type A spermatogonia. Effects at other sites in spermatogenesis are suggested by the changes in spermatocyte and spermatid populations. However, to clarify these effects, selective FSH withdrawal would need to be prolonged until steady state had been achieved.

Transpupillary thermotherapy as primary treatment for small choroidal melanomas

OBJECTIVE

To report the short-term follow-up results of eyes containing small choroidal melanomas that were treated with transpupillary thermotherapy.

METHODS

Twenty eyes with suspected small choroidal melanomas were treated with transpupillary thermotherapy using infrared light delivered from the diode laser.

RESULTS

The age of the patients ranged from 26 to 82 years. In 14 patients, there was documented growth of the melanoma before transpupillary thermotherapy. The tumor thickness ranged from less than 1.0 to 3.2 mm. Seven tumors were treated more than once. Follow-up ranged from 6 months to more than 3 years. Following treatment, the tumor thickness decreased in all cases, usually within 2 months. Progressive atrophy of tumor mass and loss of pigmentation within the tumor continued beyond 1 year of follow-up in some eyes. Complications included field defects, vascular changes, and macular abnormalities.

CONCLUSIONS

Transpupillary thermotherapy of small choroidal melanomas is usually followed by early tumor shrinkage but is complicated by dense scotomas, nerve fiber bundle defects, and, occasionally, macular abnormalities. The short-term follow-up results suggest that transpupillary thermotherapy may arrest the growth of selected small melanomas.

[Inhibin and ovarian cancer]

Previous observations from our laboratory have demonstrated that the levels of immunoreactive inhibin (ir-inh) are elevated in almost all patients with granulosa cell tumors and in the majority of postmenopausal women with mucinous ovarian cancers. The present report confirms these findings in a larger group of post-menopausal women. Immunohistochemistry for the inhibin alpha. beta A and beta B sununits shows predominantly epithelial staining in granulosa cell tumors and in the majority of mucinous cancers. Serous cystadenocarcinomas also frequently show positive staining. Studies seeking to identify G alpha i-2 or FSH receptor mutations have provided negative results in contrast to other reports. Further studies of the roles of the inhibin-related family of peptides in ovarian cancer diagnosis and monitoring are clearly indicated.

Choroidal melanomas with a collar-button configuration: response pattern after iodine 125 brachytherapy

OBJECTIVE

To describe a distinctive type of postbrachytherapy response pattern among choroidal melanomas with a collar-button configuration.

METHODS

Ninety-three consecutive eyes with choroidal melanoma treated with iodine I 125 brachytherapy before 1991 were reviewed to identify melanomas with a collar-button configuration. Postbrachytherapy response patterns of these melanomas were reviewed.

RESULTS

Thirty-four of the 93 eyes contained tumors with a collar-button configuration. Sixteen (47%) of the 34 eyes demonstrated a postbrachytherapy response pattern characterized by persistence of the collar-button, while the body of the tumor demonstrated shrinkage. During follow-up, the color of the collar-button configuration changed from light brown to dark chocolate (16 [47%] of 34 eyes). Subsequently, irregularly clumped, darkly pigmented debris was observed to slough from the surface of the collar-button configuration into the vitreous cavity (7 [21%] of 34 eyes). The debris was comprised largely of pigment-laden macrophages in 1 eye in which a vitrectomy was performed. In another eye, histopathologic study of spherical clusters of intravitreal brown-colored debris identified malignant melanoma cells.

CONCLUSIONS

A distinctive postbrachytherapy regression pattern of melanoma with a collar-button configuration has been identified. The main body of the tumor shrinks, whereas the collar-button configuration persists, appears more prominent, gradually changes to a darker color, and may then shed pigmented debris into the vitreous cavity. This pigmented debris may be composed of pigment-laden macrophages and/or melanoma cells. Clinical characteristics of the vitreous debris may help distinguish malignant invasion by melanoma cells from infiltration by nonmalignant debris and macrophages.

Follicle-stimulating hormone and testosterone stimulation of immature and mature Sertoli cells in vitro: inhibin and N-cadherin levels and round spermatid binding

The in vitro response of Sertoli cells isolated from adult rat testes to testosterone (T) and follicle-stimulating hormone (FSH) treatment was investigated. Sertoli cells from >70-day-old Sprague-Dawley rats were isolated by a combined enzymatic treatment followed by the removal of the majority of contaminating germ cells with immobilized peanut agglutinin lectin. Sertoli cells were then cultured for 6-10 days, forming a confluent layer with a cell viability of >83% and 74-77% purity. The contaminating cells were peritubular cells (4-6%), pachytene spermatocytes (4-5%), round spermatids (<2%), elongated spermatids (<1%), and degenerating germ cells (14.8%). The proportion of degenerating germ cells decreased from 14.8% to 8.6% between days 6 and 10 in culture. After a prestimulation culture period of 4 days, FSH treatment over a 2-day period resulted in a dose-related increase of inhibin with a median effective dose (ED50) value of 36.7+/-20.4 ng/ml in comparison with an ED50 value of 4.4+/-0.9 ng/ml obtained with immature Sertoli cell cultures from 20-day-old rats. Mature Sertoli cells, in contrast to immature Sertoli cells, were unresponsive to combined FSH + T treatment for the production of the cell adhesion protein N-cadherin. FSH treatment promoted the in vitro binding of round spermatids isolated from adult testis to adult Sertoli cells in coculture. It is concluded that mature Sertoli cells in culture are responsive to FSH in terms of inhibin production and round-spermatid binding. The lack of an FSH + T-induced increase in N-cadherin or round spermatid binding is attributed to either a reduced sensitivity, or an alteration in the regulation of mature Sertoli cells by FSH + T.

Combined inhibin and CA125 assays in the detection of ovarian cancer

BACKGROUND

The reproductive hormone inhibin has been used as a diagnostic marker of ovarian mucinous and granulosa cell cancers. The aims of this study were to develop a new inhibin immunofluorometric assay (alphaC IFMA) to replace an inhibin RIA as a diagnostic marker of these ovarian cancers and to assess whether the alphaC IFMA in combination with CA125, which detects serous cancers, leads to an improved biochemical diagnosis of all ovarian cancers.

METHODS

Serum inhibin concentrations were determined in healthy postmenopausal women (n = 165) and women with ovarian cancers (n = 154), using an inhibin RIA and an alphaC IFMA, which detects inhibin forms containing the alphaC subunit as well as the free alphaC subunit.

RESULTS

The alphaC IFMA gave a similar or better discrimination of mucinous (90% vs 71%) and granulosa cell (100% vs 100%) cancers compared with the inhibin RIA. Combination of CA125 and alphaC IFMA values by canonical variate analysis or by multiROC analysis showed that the percentage of all ovarian cancers detected was significantly increased compared with either CA125 or alphaC IFMA alone.

CONCLUSIONS

The alphaC IFMA shows a similar or better specificity compared with the RIA, but with increased sensitivity. In combination with CA125, the alphaC IFMA provides an effective dual test for the detection of the majority (90%) of ovarian cancers.

Treatment choice and quality of life in patients with choroidal melanoma

OBJECTIVE

To determine if quality of life differs between patients with choroidal melanoma treated with enucleation and those treated with radiation therapy.

MATERIALS AND METHODS

Patients treated for choroidal melanoma at 5 Midwest centers were asked to participate. There were 65 participants treated with enucleation and 82 treated with radiation therapy. Quality of life was assessed using the Medical Outcome Study Short Form 36 and the National Eye Institute Visual Function Questionnaire and by the Time-Tradeoff interview method.

RESULTS

The average length of follow-up was 4.9 years for the group treated with radiation therapy and 6.3 years for the group treated with enucleation (P = .05). After adjusting for age, sex, years of follow-up, and the number of chronic conditions, there were few differences in any of the quality-of-life measures by treatment status. Participants in the group treated with radiation therapy were more likely to have higher (better) scores on the Vitality and Mental Component subscales of the Medical Outcome Study Short Form 36 than participants treated with enucleation. There were no differences on the National Eye Institute Visual Function Questionnaire or the Time-Tradeoff measures of quality of life.

CONCLUSION

Choice of treatment for choroidal melanoma does not seem to be associated with large differences in quality of life in long-term follow-up.

Inhibin forms in serum from postmenopausal women with ovarian cancers

BACKGROUND AND OBJECTIVE

Previous studies have shown that serum inhibin as measured by alpha subunit-directed radioimmunoassay (RIA) and inhibin A ELISA was elevated in postmenopausal women with mucinous and granulosa cell cancers, with the RIA showing a more frequent elevation than the inhibin A ELISA. It was thus hypothesised that these cancers may also produce inhibin B or the free alpha subunit. The aim of the study was to identify the forms of inhibin found in a range of ovarian cancers using a range of inhibin assays with varying specificities.

DESIGN

Serum samples obtained from women with ovarian cancer were assayed by inhibin B ELISA and Pro-alpha C subunit ELISA and compared with inhibin RIA and inhibin A ELISA.

PATIENTS

Blood samples were obtained from 34 postmenopausal women (> 55 years) with no history of endocrine disease and from women with ovarian serous cystadenocarcinomas (n = 66), mucinous cystadenocarcinomas (n = 20), granulosa cell tumours (n = 9-11), miscellaneous ovarian cancers (n = 46) and non ovarian cancers (n = 23).

MEASUREMENTS

Inhibin B and inhibin Pro-alpha C subunit levels were determined by ELISA and compared to values obtained by RIA and inhibin A ELISA. Cancers were discriminated from controls based on values obtained 2SD above the geometric mean of the control values.

RESULTS

Granulosa cell tumours were detected by RIA and inhibin B ELISA (100%), Pro-alpha C ELISA (90%) and inhibin A ELISA (77%). Mucinous tumours were detected by RIA (70%), inhibin B ELISA (60%), Pro-alpha C ELISA (55%) and inhibin A (20%). Serous tumours were detected by RIA (35%) and the other assays (< 15%). Miscellaneous tumours were detected by RIA (41%) and other assays < 30%.

CONCLUSIONS

Ovarian neoplasms may produce a variety of peptides related to the inhibins, including dimeric inhibin A and B. Inhibin B is detected in more ovarian cancers than inhibin A but does not discriminate as well as the alpha subunit directed assays. The higher discrimination index obtained with the RIA compared to the Pro-alpha C ELISA suggests that assays detecting all inhibin forms containing the alpha subunit and not just those detecting the Pro-alpha C subunit will provide the most useful detection method.

Identification of high affinity binding sites for inhibin on ovine pituitary cells in culture

The aim of this study was to identify and characterize binding sites for inhibin in primary cultures of ovine anterior pituitary cells. Recombinant human 31-kDa inhibin A was iodinated by an optimized lactoperoxidase procedure. Fractionation of the labeled protein by gel filtration chromatography on Sephadex G-100 in 0.1 M HCl yielded two immunoactive peak regions, the second of which was bioactive as assessed by in vitro bioassay, with a ratio of bioactivity/immunoactivity of 0.62-0.77 and an iodine incorporation ratio of 1.7-2.0 mol 125I/mol inhibin. The specific binding of purified [125I]inhibin to cultured ovine pituitary cells varied with time, temperature, and cell number. Displacement of the tracer by unlabeled inhibin, as assessed by Scatchard analysis, revealed two binding sites with average Kd values of 0.28 and 3.9 nM and with approximately 250 and 3100 binding sites/anterior pituitary cell, respectively. There was little cross-reaction between inhibin and activin A (<2%), transforming growth factor-beta (<0.2%), or follistatin (<<0.1%). Examination of cell lines that were not expected to have inhibin receptors showed that there was no specific binding of inhibin to human leukemia (Jurkat) cells, whereas the binding to human embryonic kidney (293) cells was displaced by both inhibin and activin with a similar degree of cross-reaction, which suggests binding to an activin receptor. It is concluded that inhibin-binding sites with high affinity and specificity have been identified on ovine pituitary cells, consistent with both inhibin action on the pituitary and the presence of the putative inhibin receptor.

Transpupillary thermotherapy as primary treatment for small choroidal melanomas

PURPOSE

To report short-term follow-up of eyes containing small choroidal melanomas that were treated with transpupillary thermotherapy (TTT).

METHODS

Twenty eyes with suspected small choroidal melanomas were treated with TTT using infrared light delivered from the diode laser.

RESULTS

The age of patients ranged from 26 to 82 years. In 14, there was documented growth of the melanoma prior to TTT. Tumor thicknesses ranged from less than 1 to 3.2 mm. Seven tumors were treated more than once. Follow-up ranged from 6 months to more than 3 years. Following treatment, tumor thicknesses decreased in all cases, usually within 2 months. Progressive atrophy of tumor mass and loss of pigmentation within the tumor continued beyond 1 year of follow-up in some eyes. Complications included field defects, vascular changes, and macular abnormalities.

CONCLUSIONS

Transpupillary thermotherapy of small choroidal melanomas is usually followed by early tumor shrinkage but is complicated by dense scotomas, nerve fiber bundle defects, and occasionally macular abnormalities. Short-term follow-up suggests that TTT may arrest growth of selected small melanomas.

Retinal detachment in Olmsted County, Minnesota, 1976 through 1995

OBJECTIVE

To estimate the incidence of rhegmatogenous retinal detachment (RD) in a geographically defined population and to compare the probability of RD in residents after cataract extraction with the probability of RD in residents who did not have cataract extraction.

DESIGN

Rochester Epidemiology Project databases were used to perform a retrospective population-based incidence study of RD diagnosed between 1976 and 1995 with cohort analyses of the influence of risk factors on the occurrence of RD.

PARTICIPANTS

The population of Olmsted County, Minnesota, participated.

MAIN OUTCOME MEASURE

Incidence rates of RD adjusted to the age and gender distribution of the 1990 U.S. white population were measured.

RESULTS

Three hundred eleven incident cases of rhegmatogenous RD were identified. The mean annual age- and gender-adjusted incidence rate of rhegmatogenous RD was 17.9 per 100,000 persons (95% confidence interval [CI], 15.9-19.9). For idiopathic rhegmatogenous RD alone, the mean annual age- and gender-adjusted incidence rate was 12.6 (95% CI, 10.9-14.3) per 100,000 persons. Ten years after phacoemulsification and extracapsular cataract extraction, the estimated cumulative probability of RD was 5.5 (95% CI, 3.4-7.6) times as high as would have been expected in a similar group of county residents not undergoing cataract surgery.

CONCLUSIONS

Cataract surgery is associated with a significantly elevated long-term cumulative probability of retinal detachment.

Testosterone-dependent restoration of spermatogenesis in adult rats is impaired by a 5alpha-reductase inhibitor

Germ cell development (spermiogenesis in particular) in the adult rat is known to be testosterone dependent. Recently we proposed a role for the 5alpha reduction of testosterone to dihydrotestosterone (DHT) in the short-term restoration of round spermatid maturation when testicular testosterone levels are experimentally lowered. The current study aimed to further characterize the involvement of 5alpha-reductase in the restoration of spermatogenesis by investigating the short- and long-term restoration of specific germ cell populations by testosterone in the presence or absence of a 5alpha-reductase inhibitor (L685,273). Spermatogenesis in adult rats was suppressed for 8 weeks using 3-cm testosterone and 0.4-cm estradiol silastic implants (testosterone-estradiol [TE] treatment); spermatogenesis was then restored by administration of increasing doses of testosterone with or without a competitive 5alpha-reductase inhibitor or with the androgen receptor antagonist flutamide. Animals were then killed after either 4 days or 6 weeks of treatment so that we could study the short- and long-term restorations of spermatogenesis. Stereological analysis showed that germ cell development between late pachytene spermatocytes to round spermatids in stage VII during either short- or long-term restoration was not affected by 5alpha-reductase inhibition, but it was affected by flutamide. The conversion of round spermatids between stages VII and VIII was restored by testosterone treatment, but this restoration was prevented by flutamide. Both the short- and long-term restorations of this midspermiogenic event were significantly decreased when 5alpha-reductase was inhibited. After long-term restoration of spermatogenesis, elongated spermatids were restored to 42% of control but were significantly suppressed to 20% of control by coadministration of the 5alpha-reductase inhibitor because of a reduction in the number of round spermatids progressing between stages VII and VIII. The results demonstrate that the 5alpha-reduction of testosterone is particularly important for progression through midspermiogenesis, because this phase of germ cell development is more sensitive to withdrawal of androgens. We suggest that testicular 5alpha-reductase activity is important for the restoration or maintenance of low levels of sperm production in a hormonally based contraceptive setting.

Visual impairment due to macular disciform scars in a 20-year-old man with Smith-Magenis syndrome: another ophthalmologic complication

We describe a 20-year-old man with Smith-Magenis syndrome and a 46,XY,del(17)(p11.2p11.2) karyotype. The interstitial deletion was confirmed by metaphase analysis using the fluorescent in situ hybridization probe (D17S29) for the Smith-Magenis region. The patient had hypertelorism, exotropia, and high myopia. Examination under anesthesia showed a lacquer crack near the right macula and a disciform scar of the left macula. Six months later, the patient presented with subacute visual loss. Examination demonstrated end-stage macula degeneration with bilateral disciform scars. There was no evidence of retinal detachment. Prior reports of Smith-Magenis syndrome mention telecanthus, ptosis, strabismus, iris anomalies, cataract, microcornea, optic nerve hypoplasia, myopia, retinal detachment, and lattice retinal degeneration. Bilateral macular degeneration has not been reported previously, and it may be an additional ophthalmologic manifestation of Smith-Magenis syndrome, either as a primary manifestation or as a direct consequence of high myopia.

Both inhibin A and B respond to exogenous follicle-stimulating hormone in the follicular phase of the human menstrual cycle

To ascertain whether changes in the concentrations of the dimeric inhibins A and/or B (INH-A and INH-B) contributed to the previously described dose-dependent increase in immunoreactive inhibin (INH) in response to FSH during the follicular phase of the human menstrual cycle, both dimers were measured by specific two-site assays in stored serum samples from regularly cycling normal volunteers who had received saline as a control (n = 5) or FSH [100 IU (n = 6) or 200 IU (n = 5)] between days 3-5 of the menstrual cycle. Both INH-A and INH-B showed a dose-dependent increase in response to administered FSH; INH-A rose from 13.5 to 35.9 ng/L (P < 0.01), and INH-B rose from 77.8 to 205 ng/L (P < 0.05) at 36 h after 200 IU FSH. Highly significant correlations were observed between INH and each of the specific inhibin dimers (A: r = 0.79, P < 0.001; B: r = 0.76, P < 0.001), and the responses of the two dimers were also highly correlated (r = 0.59, P < 0.001). The response of each inhibin was also highly correlated with the response of serum estradiol (A: r = 0.45, P < 0.001; B: r = 0.40, P < 0.001). When analyzed by ANOVA, the INH response of INH-B was significantly above the control value at 36 h after treatment with both 100 and 200 IU FSH, whereas the response of INH-A was significant only at 200 IU. It is concluded that the concentrations of both dimeric INH-A and INH-B are stimulated by increases in FSH within the physiological range in the follicular phase of the human menstrual cycle and that both contribute to the previously observed rise in INH.

Follicle-stimulating hormone is required for the initial phase of spermatogenic restoration in adult rats following gonadotropin suppression

The role of follicle-stimulating hormone (FSH) in adult rat spermatogenesis is unclear. Although exogenous testosterone (T) restores spermatogenesis following gonadotropin-releasing hormone (GnRH) immunization or T plus estradiol (TE) treatments, an assessment of the independent action of T and FSH was not possible, as exogenous T treatment maintains serum FSH levels. We have used passive immunization against FSH to determine whether T alone is capable of reinitiating spermatogenesis after chronic and acute FSH withdrawal. Adult rats received T-filled Silastic implants 6 cm (T6) or 8 cm (T24) in length for 7 days in combination with either a polyclonal sheep antisera raised against rat FSH (FSHAb, 2 mg/kg SC daily) or control sheep immunoglobulin (ConAb) after either GnRH immunization (12 weeks) or TE treatment (9 weeks). The neutralizing capacity of the FSHAb was determined using a FSH in vitro bioassay; this analysis demonstrated that administration of FSHAb in vivo reduced FSH levels by >90%. Testes were fixed and germ cell number per testis quantified using the optical dissector. GnRH immunization reduced spermatogonia, pachytene spermatocytes, and round spermatids to 50, 13, and <1% of normal, respectively. T6 and T24 Silastic implants with the inclusion of the FSHAb did not increase the number of spermatogonia, pachytene spermatocytes, and round spermatids (50, 15, and 1% of normal, respectively). T6+ConAb treatment increased spermatogonial, pachytene spermatocyte, and round spermatid numbers to 74, 30, and 3% of normal, respectively (P < 0.05). No further increases were seen with T24 implants. TE treatment suppressed pachytene spermatocytes and round spermatids to 33 and 1% of normal, respectively (P < 0.05). T6+FSHAb treatment did not increase the number of pachytene spermatocytes and round spermatids (36 and 8%, respectively), whereas T6+ConAb treatment increased pachytene spermatocyte and round spermatid number to 50 and 28% of normal, respectively (P < 0.05). T24+FSHAb treatment increased the number of pachytene spermatocyte and round spermatids (56 and 22% of normal, respectively; P < 0.05), whereas T24+ConAb treatment increased these cells forms to 79 and 31% of normal, respectively. In conclusion, T alone is unable to restore spermatogenic cell populations in the setting of chronic FSH withdrawal. Although acute FSH withdrawal markedly impairs the restoration process, higher doses of T can partially compensate for the lack of FSH. These data suggest that FSH is important for the initial phase of spermatogenic restoration.

Second nonocular tumors in survivors of heritable retinoblastoma and prior radiation therapy

PURPOSE

The principal objectives of this study were to estimate the incidence of second tumors among children treated for heritable retinoblastoma during a 50-year period and to investigate the relationship between these tumors and previous radiation therapy.

METHODS

The records of all retinoblastoma patients examined at the Mayo Clinic from 1941 through 1990 were retrospectively reviewed. The therapeutic modality used to manage the tumor, the occurrence of any second malignancy, and current follow-up on all patients were evaluated.

RESULTS

Eighty-two (46%) of 180 children with retinoblastoma had bilateral tumors (76 patients) or unilateral disease and a positive family history (six patients) and were followed for an average of 21.8 years (range, 1 month to 53 years). The Kaplan-Meier estimates of second nonocular tumors among the 82 patients with heritable retinoblastoma were 12% at 10 years, 16% at 25 years, and 30% at 40 years. Although 14 of the 15 patients who developed second malignancies had received radiation therapy, only four of the malignancies occurred within the field of irradiation.

CONCLUSIONS

The relatively low incidence of second tumors among long-term survivors of heritable retinoblastoma in this series of patients occurred predominantly outside the field of irradiation. The variable incidence of second nonocular malignancies in previous reports may reflect variations in radiation technique and dosage.