The roles of inhibin and related peptides in gonadal function.

Inhibin A and B are dimeric proteins capable of suppressing FSH both in vitro and in vivo. The principal form in the male is inhibin B which is produced in the testis and circulates to inhibit pituitary FSH secretion. Activin A, B and AB are dimeric proteins that share the same beta subunits with the inhibins but, in contrast, stimulate FSH secretion.

The glycolytic enzyme enolase is present in sperm tail and displays nucleotide-dependent association with microtubules.

We examined the expression and localisation of enolase (2-phospho-D-glycerate hydrolase) in differentiating rat spermatogenic cells. We found that enolase is most abundant in mature spermatozoa and in residual cytoplasmic bodies detached from elongating spermatids with little to no enolase detected in meiotic primary spermatocytes and round spermatids. We localised enolase mostly to the tail of mature spermatozoa by immunoblotting and by immunofluorescence.

Percentage of free PSA in black versus white men for detection and staging of prostate cancer: a prospective multicenter clinical trial.

Objectives: In predominately white populations, measurement of the percentage of free prostate-specific antigen (%fPSA) has been shown to enhance the specificity of total PSA testing for prostate cancer while maintaining high sensitivity and to aid in prostate cancer staging. This study evaluated whether the %fPSA cutoff that maintained a 95% sensitivity in a white population yielded the same sensitivity and specificity in a black population and whether %fPSA was useful in predicting postoperative pathologic features in blacks.

Methods: We evaluated 647 white and 79 black men, prospectively enrolled at prostate cancer screening and surgical referral centers.

Assessment of orientation: relationship between informant report and direct measures.

Although informant reports of everyday functioning are often used in dementia assessments, the actual correspondence between such indirect reports of functioning and actual performance has not been examined. Orientation results on the Dementia Questionnaire for Mentally Retarded Persons were compared to those obtained in direct assessment of orientation of 138 adults with mental retardation. Fair to good agreement was found between informant report and direct assessment.

Application of morphometric techniques to postnatal rat testes in organ culture: insights into testis growth.

The extent of Sertoli cell proliferation during fetal and neonatal development determines the final adult testis size and potential for sperm output. To gain further knowledge of the factors that regulate Sertoli cell proliferation, the present study used a new approach to analyse changes in morphology and proliferation in the postnatal testis by combining organ culture with morphometric analysis. Fragments of rat testes from days 0 to 10 postpartum were cultured in contact with DMEM for 6 h or 72 h and fixed.

Prediction of post-radical prostatectomy pathological outcome for stage T1c prostate cancer with percent free prostate specific antigen: a prospective multicenter clinical trial.

Purpose: Prostate specific antigen (PSA) exists in bound (complexed) and unbound (free) forms in serum. The percentage of free PSA enhances the specificity of PSA testing for prostate cancer detection. We evaluated the use of percent free PSA preoperatively to predict pathological stage.

Testisin, a new human serine proteinase expressed by premeiotic testicular germ cells and lost in testicular germ cell tumors.

We have cloned and characterized a cDNA encoding a new human serine proteinase, testisin, that is abundantly expressed only in the testis and is lost in testicular tumors. The testisin cDNA was identified by homology cloning using degenerate primers directed at conserved sequence motifs within the catalytic regions of serine proteinases. It is 1073 nucleotides long, including 942 nucleotides of open reading frame and a 113-nucleotide 3' untranslated sequence.

Novel low molecular weight microtubule-associated protein-2 isoforms contain a functional nuclear localization sequence.

Known high and low molecular weight (LMW) MAP2 protein isoforms result from alternative splicing of the MAP2 gene. Contrary to previous reports that MAP2 is neural-specific, we recently identified MAP2 mRNA and protein in somatic and germ cells of rat testis, and showed the predominant testicular isoform is LMW. Although cytoplasmic in neural tissue, MAP2 appeared predominantly nuclear in germ cells using immunohistochemistry.

Expression of mixed lineage kinase 2 in germ cells of the testis.

Mixed Lineage Kinase 2 is a mammalian protein kinase that activates stress-activated protein kinases/c-jun N-terminal kinases (SAPK/JNKs) through direct phosphorylation of their upstream activator, SEK1/JNKK. We have examined expression of both MLK2 and SEK1/JNKK RNAs in the rat testis at various times during postnatal development and in isolated testicular cell populations. We also have used immunohistochemistry to examine MLK2 protein expression and localization in adult rat and mouse testis.

Dementia in adults with Down syndrome: diagnostic challenges.

Although dementia associated with Down syndrome is often presumed to be progressive and irreversible, variations in disease course have been described. In addition, prevalence rates have varied widely among studies. This interim report is a description of the status of 70 adults with Down syndrome who are being followed for signs of dementia.

Apoptosis regulator bcl-w is essential for spermatogenesis but appears otherwise redundant.

Proteins of the Bcl-2 family are important regulators of apoptosis in many tissues of the embryo and adult. The recently isolated bcl-w gene encodes a pro-survival member of the Bcl-2 family, which is widely expressed. To explore its physiological role, we have inactivated the bcl-w gene in the mouse by homologous recombination.

The Vineland Adaptive Behavior Scales: supplementary norms for individuals with autism.

Vineland Adaptive Behavior Scales Special Population norms are presented for four groups of individuals with autism: (a) mute children under 10 years of age; (b) children with at least some verbal skills under 10 years of age; (c) mute individuals who are 10 years of age or older; and (d) individuals with at least some verbal skills who are 10 years of age or older. The sample included 684 autistic individuals ascertained from cases referred for the DSM-IV autism/PDD field trial collaborative study and five university sites with expertise in autism. Young children had higher standard scores than older individuals across all Vineland domains.

Are there clinical and laboratory predictors of 5-year mortality in HIV-infected children and adolescents with hemophilia?

To determine factors associated with survival in a cohort of HIV-infected children and adolescents with hemophilia, an analysis of the 5-year mortality data for 207 HIV-infected young men was performed to examine the effect of selected clinical covariates on survival. The subjects were enrolled into the Hemophilia Growth and Development Study cohort from 1989 to 1990. Estimated mean time since infection at baseline was 6.

Spermatogenesis.

Spermatogenesis is a complex process involving mitotic cell division, meiosis and the process of spermiogenesis. The regulation of spermatogenesis involves both endocrine and paracrine mechanisms. The endocrine stimulation of spermatogenesis involves both follicle stimulating hormone (FSH) and luteinizing hormone, the latter acting through the intermediary testosterone, produced by the Leydig cells in the testis.

Localization of follistatin in the rat testis.

The cellular localization of the activin-binding protein, follistatin, in the rat testis has been a matter of some controversy with different investigators claiming that Sertoli cells, Leydig cells or germ cells are the primary cell types containing this protein. The localization of mRNA encoding follistatin was re-examined using reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization as well as the distribution of follistatin by immunohistochemistry. The results demonstrate that mRNA encoding follistatin is located in many germ cells including type B spermatogonia, primary spermatocytes with the exception of the late leptotene and early zygotene stages, and spermatids at steps 1 to 11.

Identification of a rat testis-specific gene encoding a potential rat outer dense fibre protein.

Screening of a rat testis expression library with an antiserum specific for an outer dense fibre (ODF) has led to the identification of a gene encoding for a putative protein previously unknown as a component of the sperm tail. This gene has been designated tpx-1 by virtue of its homology with the mouse and human gene of the same name (79 and 73%, respectively). The tpx-1-like gene encoded a 1.

Use of the percentage of free prostate-specific antigen to enhance differentiation of prostate cancer from benign prostatic disease: a prospective multicenter clinical trial.

Context: The percentage of free prostate-specific antigen (PSA) in serum has been shown to enhance the specificity of PSA testing for prostate cancer detection, but earlier studies provided only preliminary cutoffs for clinical use.

Objective: To develop risk assessment guidelines and a cutoff value for defining abnormal percentage of free PSA in a population of men to whom the test would be applied.

Design: Prospective blinded study using the Tandem PSA and free PSA assays (Hybritech Inc, San Diego, Calif).

Developmental changes in the basement membrane of the normal and hypothyroid postnatal rat testis: segmental localization of fibulin-2 and fibronectin.

To characterize developmental changes in the extracellular matrix of the postnatal rat testis in relationship to the timing of germ cell maturation, we immunolocalized fibulin-1, fibulin-2, and other matrix components in the testes of normal and propyl-thiouracil (PTU)-induced hypothyroid animals. Unlike laminin, nidogen, and perlecan, which were present in the seminiferous tubule basement membrane (BM) throughout postnatal development, fibulins were found to disappear from the postnatal tubule BM. Fibulin-1 was no longer detected after Day 5 whereas fibulin-2 became localized in a segmental manner within the BM of each seminiferous tubule on Days 10 and 15 and disappeared by Day 20.

Hemophilia growth and development study: relationships between neuropsychological, neurological, and MRI findings at baseline.

Objective: To determine the effects of human immunodeficiency virus (HIV) infection on children's development by identifying neurological and environmental variables associated with neuropsychological measures of cognitive development in HIV-seronegative (HIV-) and HIV-seropositive (HIV+)children and adolescents with hemophilia.

Methods: Participants (N = 298; 60% HIV+) were males ages 7-19 years enrolled in the Hemophilia Growth and Development Study (HGDS). Least squares modeling was used to determine whether there was a difference at baseline in mean neuropsychological test scores by HIV status, age, and neurological baseline findings, adjusting for selected environmental and medical history variables.

Emotion recognition in autism: verbal and nonverbal information.

This study examined the roles of verbal and nonverbal sources of information in the ability of persons with and without autism to recognize emotion. Child, adolescent, and young adult participants in four groups [Lower Functioning Autism (LFA) (n = 17), High Functioning Autism (HFA) (n = 18), Lower Functioning Comparison (LFC) (n = 18), and High Functioning Comparison (HFC) (n = 23)] identified emotions shown (happy, angry, sad, surprised, or neutral) in video clips of individuals expressing emotion verbally, nonverbally, or both. Verbal expressions of emotion were either Explicit, Implicit, or Neutral, whereas nonverbal expressions were Animate or Flat (3 x 2).

Analytical performance of the Tandem-R free PSA immunoassay measuring free prostate-specific antigen.

The analytical performance of the Tandem-R free PSA assay available from Hybritech Inc. was evaluated. Comparison of recoveries of purified free (unbound) prostate-specific antigen (PSA) diluted in female serum in the Tandem-R free PSA assay and the Tandem-R (total) PSA assay demonstrated a link in calibration between the assays and an accurate determination of percent free PSA.

Stem cell factor and c-kit in the mammalian testis: lessons originating from Mother Nature's gene knockouts.

Analysis of mice with naturally occurring mutation in the genes encoding the tyrosine kinase receptor protein, c-kit, and its ligand, stem cell factor (SCF), has implicated these proteins in testicular development and function because of the phenotype of these mice of reduced or absent fertility. Descriptive and functional studies have highlighted the involvement of these proteins in primordial germ cell migration and survival, and in spermatogonial proliferation, survival and adhesion. This review summarises the current knowledge regarding functions of c-kit and SCF in the testis and discusses the implications of information gleaned from other biological systems.

Expression of stem cell factor in the postnatal rat testis.

The expression of stem cell factor (SCF) mRNA and protein was examined in the postnatal rat testis. Northern blot analysis of total RNA from 1-4 days postpartum (dpp) testes showed none or barely detectable levels of the approximately 6.5 kb SCF transcript.