Follistatin and activin A production by the male reproductive tract

Follistatin is a binding protein for the activin and inhibin family of hormones, regulating their biological activity. In the male reproductive tract, the interaction of these factors is likely to be involved in the regulation of the proliferation of several cell types. We have investigated the presence of follistatin and activin A in seminal plasma using specific immunoassays and have localized follistatin and activin/inhibin subunits in the adult human testis, prostate and seminal vesicle to establish their likely sources. High concentrations of immunoreactive follistatin were present in seminal plasma in normal men (mean 97.9 ng/ml; 1.43 ng/ml in peripheral plasma) and were similar in men with oligo/azoospermia and following vasectomy. Follistatin immunoreactivity was localized to both Leydig and Sertoli cells of the testis, and to epithelial cells of the prostate gland and seminal vesicle, which are likely to be the predominant sources of the hormone in seminal plasma. Activin A was also present in seminal plasma in normal men but was undetectable following vasectomy, thus deriving from the testis. Consistent with this finding, the betaA-subunit was immunolocalized in Sertoli and Leydig cells but was not present in seminal vesicle or prostate gland. The functional significance of the high concentrations of follistatin secreted into seminal plasma by the prostate gland and/or seminal vesicle is uncertain, but they may regulate the biological activity of testis-derived activin A and inhibin B.      

A peptide mimetic of calcium.

Proteins of the troponin superfamily use homologous amino acid sequences as binding sites for Ca2+ and seem to have evolved from an ancestral Ca2+ binding site. We have utilized this ancestral sequence to construct a peptide (Ca(2+)-like peptide) with inverted hydropathy to the calcium-coordinating region of this protein. This synthetic peptide acted like Ca2+ in that (i) it increased the calmodulin-dependent hydrolysis of cAMP by phosphodiesterase, (ii) it interacted with EDTA, and (iii) it enhanced contraction of urinary bladder smooth muscle in vitro. Unlike Ca2+, the peptide's effects were destroyed by acid hydrolysis. These findings demonstrate the synthesis of a peptide that can substitute for Ca2+ and may have considerable utility for the study of Ca(2+)-regulated pathways and possible therapeutic value as a pharmacologic agent.     

Differentiation between organic and functional psychiatric illness in the elderly: An evaluation of four cognitive tests

One hundred and sixty-four patients admitted to a psychogeriatric unit were given a combination of four different cognitive tests: the Mini Mental State Examination (MMSE), the Abbreviated Mental Test Score, The Felix Post Unit Score and the compilation of tests recommended by the MRC Alzheimer's Disease Workshop. The tests were compared with respect to their ability to sort accurately cases of dementia and depression, and the effects of age and education on test score and misclassification rate with diagnosis controlled for. The MMSE had a very high misclassification rate for the poorly educated and depressed group. The logistical discriminant functional analysis selected only eight items as the best discriminators between organic/ functional or dementia/depression groups. Only one of these eight was not either a memory or orientation test. The value of simply adding up tests of different aspects of cognitive function in dementia assessment or screening is questioned.     

Comparison of monochromatic ocular aberrations measured with an objective cross-cylinder aberroscope and a Shack-Hartmann aberrometer.

Repeated measures of wavefront aberrations were taken along the line-of-sight of seven eyes using two instruments: an objective, cross-cylinder aberroscope (OA) and a Shack-Hartmann (SH) aberrometer. Both instruments were implemented on the same optical table to facilitate interleaved measurements on the same eyes under similar experimental conditions. Variability of repeated measures of individual coefficients tended to be much greater for OA data than for SH data. Although Zernike coefficients obtained from a single measurement were generally larger when measured with the OA than with the SH, the averages across five trials were often smaller for the OA. The Zernike coefficients obtained from the two instruments were not significantly correlated. Radial modulation-transfer functions and point-spread functions derived from the two sets of measurements were similar for some subjects, but not all. When average Zernike coefficients were used to determine optical quality, the OA indicated superior optics in some eyes, but the reverse trend was true if Zernike coefficients from individual trials were used. Possible reasons for discrepancies between the OA and SH measurements include difference in sampling density, quality of data images, alignment errors, and temporal fluctuations. Multivariate statistical analysis indicated that the SH aberrometer discriminated between subjects much better than did the objective aberroscope.     

Surveillance for stage I non-seminomatous germ cell tumours of the testis: the optimal protocol has not yet been defined

Forty-six patients with clinical stage I testicular non-seminomatous germ cell tumours were followed up according to a protocol of active surveillance between 1979 and 1987. The median follow-up time was 40+ months. Thirteen patients (28%) relapsed, predominantly in retroperitoneum and/or lung. Ten of these relapses (76%) occurred within 8 months of orchiectomy. Relapses occurred in 7/35 T1 tumours and 5/10 T2 to T4 tumours. No correlation was detected between the histological type and relapse rate. Three late relapses were diagnosed at 23, 29 and 36 months. Eleven of the relapsed patients remain in prolonged complete remission after PVB chemotherapy +/- surgery; one patient, who initially refused treatment at the time of relapse, has died. Another relapsed with predominant elements of rhabdomyosarcoma intermingled with malignant teratoma in a bone metastasis. He had a partial response to PVB chemotherapy but subsequently died. Thirty-four patients (74%) did not undergo lymphography (LG) and had a higher relapse rate (11/34) than those who had LG (2/12); this was not a statistically significant difference in this small series. The policy of active surveillance is not yet the "state of the art" and should be under constant scrutiny with respect to safety and practice.     

Lymphocyte β-adrenergic receptor binding in panic disorder

Lymphocyte beta adrenergic receptor binding using [¹²⁵I]CNP was determined in patients with panic disorder (N=4) or agoraphobia with panic attacks (N=17) and age- and sex-matched healthy subjects (N=22). The patients showed a significantly lower number of -adrenergic receptor binding sites and a significantly higher affinity of binding than healthy subjects. A past or present history of major depression in the patients did not alter these findings. These results are consistent with a growing body of knowledge implicating noradrenergic dysfunction in the pathophysiology of panic anxiety.     

Macular degeneration.

With the "graying of America," the patient population at risk for developing ARMD will continue to grow. As researchers continue to study the cause, pathologic changes, and risk factors associated with the development of this disease, preventive measures and improved treatment options will become available. The education of ARMD patients in the recognition of signs of the disease for early treatment, treatment options, and the availability of resources is essential for the nurse caring for this population. Adjustment to visual loss will be an ongoing process, during which the nurse can be a source of support, guidance, and encouragement, as patients assimilate newly acquired behaviors and roles into their self-image.     

Negative parenting behavior, combat exposure, and PTSD symptom severity. Test of a person-event interaction model.

The "personal characteristics" and "extreme event" hypotheses have been proposed as alternative explanations for the development of posttraumatic stress disorder (PTSD) among combat veterans. The person-event interaction model attempts to integrate both perspectives by hypothesizing that premilitary individual vulnerability characteristics play a greater role in influencing risk of PTSD or PTSD symptom severity at lower than at higher levels of exposure to traumatic combat stressors. Focusing on a sample of 57 Vietnam veterans undergoing inpatient treatment for diagnosed PTSD, we assessed this model by examining interactions between negative parenting behaviors in childhood (e.g., inconsistent love) and degree of combat exposure in predicting PTSD symptom severity. Hierarchical regression analyses supported the model, indicating that the father's negative parenting behaviors were more predictive of PTSD symptom severity at relatively lower levels of combat exposure. Implications of the findings for further research on multivariate, interactional models of PTSD etiology among Vietnam combat veterans are discussed.