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Biomedical subjects

H Fisch

Publications and source records attributed to H Fisch.

At least 19 recordsLinked to original sources
PubMed2003

Testicular growth and gonadotrophin response associated with varicocele repair in adolescent males.

OBJECTIVE: To measure testicular volume and the gonadotrophin response to gonadotrophin-releasing hormone (GnRH) stimulation in adolescents undergoing left varicocelectomy. PATIENTS AND METHODS: Thirteen adolescents undergoing varicocelectomy had their testicular volume and endocrine function evaluated before and after surgery. RESULTS: The initial left testicular volume was consistently smaller than the right but after surgery both increased. Baseline follicle-stimulating hormone (FSH) levels and the FSH response to GnRH stimulation increased after surgery. There were no differences in luteinizing hormone and testosterone levels, and no changes in Tanner staging. CONCLUSIONS: Unilateral varicocelectomy with ipsilateral testicular atrophy results in bilateral testicular growth and increased FSH levels. In adolescent development, elevated FSH levels in conjunction with an increased response to the GnRH stimulation test represent a normal physiological response. The GnRH stimulation test cannot be used to determine which adolescent would benefit from surgical repair.

Adolescent↗
PubMed2001

Incidence and surgical repair rates of hypospadias in New York state.

OBJECTIVES: To determine the trend of hypospadias incidence in New York State (NYS) by retrospectively evaluating both the incidence and surgical repair rates of hypospadias. Epidemiologic studies in the United States and Europe have suggested an observable trend in the incidence of hypospadias during the past 30 years. A comparison of the results from these studies, however, revealed inconsistent trends. METHODS: The incidence and surgical repair rates of hypospadias between 1983 and 1995 were extracted from the Congenital Malformations Registry and State Wide Planning Research Cooperative System of NYS. Pearson's correlation coefficient was used to determine the direction and magnitude of change. RESULTS: Neither the incidence nor the repair rates of hypospadias in NYS between 1983 and 1995 changed significantly during the course of these 12 years (r = -0.225, P = 0.45 and r = -0.010, P = 0.92, respectively). CONCLUSIONS: The results demonstrated no statistically observable trend in either the incidence or surgical repair rates of hypospadias in NYS between 1983 and 1995.

Humans↗
PubMed2001

Maternal age as a risk factor for hypospadias.

PURPOSE: Hypospadias incidence rates have been widely reported to be increasing. During the last 20 years there has been a significant increase in the number of women who delay childbearing until their mid 30s. Therefore, it was of interest to determine if increasing maternal age is an independent risk factor for hypospadias. MATERIALS AND METHODS: Data from the New York State Department of Health and California Birth Defects Monitoring Program were analyzed from 1983 to 1996 by maternal age groups of less than 20, 20 to 24, 25 to 29, 30 to 34, and 35 or greater years. A Poisson model was fitted to the data from each state using maternal age and year of birth from which relative rates were calculated. RESULTS: Our analysis revealed that advancing maternal age is significantly associated with hypospadias and is most evident for severe cases. For example, in California a 50% increase in severe cases was demonstrated for children of mothers older than 35 years compared to mothers younger than 20 years (p <0.05). CONCLUSIONS: Hypospadias is significantly associated with increasing maternal age. Women who elect to delay childbearing until their mid 30s or later should be aware that their offspring are at increased risk of hypospadias.

Adult↗
PubMed2000

Mood effects of repetitive transcranial magnetic stimulation of left prefrontal cortex in healthy volunteers.

This study investigated the effect of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) of the left prefrontal cortex (LPFC) on mood in a sham-controlled crossover design. Twenty-five healthy male subjects received HF-rTMS of the LPFC in real and sham conditions. Forty trains (frequency 20 Hz, stimulation intensity 100% of individual motor threshold, train duration 2 s, intertrain interval 28 s) were applied in each session. Mood change from baseline was measured with five visual analog scales (VAS) for sadness, anxiety, happiness, tiredness and pain/discomfort. We were unable to demonstrate significant mood changes from baseline on visual analog scales after either sham or real stimulation of LPFC. There is insufficient evidence to support the general conclusion that HF-rTMS of LPFC has mood effects in healthy volunteers. Future studies should be sham-controlled, have larger sample sizes, and strictly stimulate one single region per session in order to exclude interaction effects with the previous stimulation.

Adult↗
PubMed2000

The possible effects of environmental estrogen disrupters on reproductive health.

The term environmental estrogen refers to chemical substances that exhibit some degree of estrogen-like activity. The primary emphasis for potential adverse effects resulting from exposure to environmental estrogens is on in utero exposure because such exposures can occur during critical periods of organogenesis. Assessment of biological plausibility can be based, in part, on the extensive data on the effects of diethylstilbestrol (DES). The available evidence is too limited to judge with any confidence whether sperm counts have declined during the past 50 years. Based on both animal and human data with DES, it is biologically plausible that in utero exposures to exogenous estrogenic compounds are capable of reducing sperm production in adult men. However, the apparent existence of a maternal dose threshold for DES-induced effects on sperm count undermines the likelihood that environmental estrogens, which are substantially less potent, are capable of causing similar effects.

Animals↗
PubMed2000

An examination of the sensitivity of reported trends in childhood leukemia incidence rates to geographic location and diagnostic coding (United States).

BACKGROUND: There have been conflicting reports of increased incidence of childhood leukemia in the United States with some, but not other, registries reporting increasing rates over the past two decades. Because of the reported discrepancy in childhood leukemia incidence rates an analysis of the SEER database was undertaken. METHODS: The latest SEER data (1973-1995) were analyzed for trends in childhood (age 0-14) leukemia incidence rates by histologic group (all leukemia combined, acute lymphocytic leukemia (ALL), acute mylogenous leukemia (AML), and other acute leukemia) for each SEER reporting region. RESULTS: A significant increase in ALL during 1973-1995 was observed in the combined SEER data, but the increase was a function of whether the first 3 years, data from the SEER Detroit reporting region are included. For the years 1973-1975 the Detroit region reported to much lower rates for ALL and much higher rates for "other acute leukemias" relative to the other SEER regions, resulting in an exaggerated temporal increase in ALL. CONCLUSION: Excluding both the temporal variability, and coding differences for Detroit in the 1973-1975 time frame, there has been no significant increase in childhood leukemia of any histologic group or age category in the United States from the 1970s to 1990s.

Adolescent↗
PubMed1999

Rising risk of testicular cancer by birth cohort in the United States from 1973 to 1995.

PURPOSE: Recent epidemiological studies have demonstrated an increasing incidence of testicular cancer in white men which appears to be correlated with the period of birth. Because this birth cohort phenomenon can explain etiological factors in testicular cancer, we determine whether this trend is present throughout the United States based on an analysis of testicular cancer incidence by birth cohort. MATERIALS AND METHODS: Testicular cancer incidence was obtained from the National Cancer Institute Surveillance, Epidemiology and End Results database from 1973 to 1995. Numbers of cases were extracted and grouped by 5-year birth cohorts for all testicular germ cell neoplasms. Poisson regression analysis with variables of age, time of diagnosis and birth cohort were used to determine relative risk. Poisson models were compared using computer log linear model software. RESULTS: Between 1973 and 1995 the incidence of testicular cancer in the United States increased 51% (3.61 to 5.44/100,000). Analysis of Poisson models revealed that birth cohort was strongly associated with relative risk of testicular cancer (p = 0.001). In addition, peak age at diagnosis decreased for each successive birth cohort. CONCLUSIONS: The overall incidence of testicular cancer in white men and the relative risk of testicular cancer have been increasing in the United States. This trend is strongly associated with birth cohort in concordance with previously reported European data. Moreover, testicular cancer is being diagnosed at a younger age as evidenced by a shift to the left in the age of peak incidence. These unique epidemiological patterns offer a basis for analysis of potential etiological factors.

Child↗
PubMed1999

Declining sperm counts in the United States? A critical review.

PURPOSE: Recent reports suggest declining sperm counts in the United States. These reports did not include all available data and did not account for geographic variations noted in prior studies. We examined all available data on U.S. sperm counts and evaluated whether geographic variations account for the decline suggested. MATERIALS AND METHODS: We reviewed all 29 U.S. studies from 1938 to 1996 reporting manually counted semen analyses of 9,612 fertile or presumably fertile men. We determined mean sperm concentrations by geographic location with weighted analysis of variance, and assessed any changes with time by linear regression analysis. RESULTS: Mean sperm concentrations from New York were significantly higher than from all other U.S. cities (98.6 versus 71.6 x 10(6) sperm per cc, respectively, p = 0.006). There has been no statistically significant change with time for mean sperm concentrations reported from New York (p = 0.49) or from U.S. cities other than New York (p = 0.62). Analysis without separating by location revealed a decline (p = 0.047). CONCLUSIONS: Sperm concentrations are highest in New York compared to other U.S. cities. When accounting for this geographic difference and examining all available data, there appears to be no significant change in sperm counts in the U.S. during the last 60 years. Further studies addressing the causes of geographic variations are needed.

Humans↗
PubMed1998

MacLeod revisited: sperm count distributions in 374 fertile men from 1971 to 1994.

OBJECTIVES: There has been an enormous amount of interest as to whether sperm counts are declining over time. We sought to compare a contemporary group of fertile men to those from the MacLeod study of 1951 to ascertain whether sperm counts in fertile men have changed over time. METHODS: We obtained sperm count data from 374 fertile men who banked sperm in Minnesota prior to vasectomy from 1971 to 1994 and compared them to sperm count distributions from the 1000 fertile men of MacLeod's study. Semen analyses were performed as per World Health Organization guidelines using identical techniques in both the present and MacLeod studies. RESULTS: The contemporary group had a mean sperm count of 102 +/- 81 x 10(6)/mL (median 85 x 10(6)/mL) compared to 107 +/- 74 x 10(6)/mL (median 90 x 10(6)/mL) for MacLeod's data. There are no significant differences in mean or median sperm counts or sperm count distributions between the groups. CONCLUSIONS: We find remarkable similarities in sperm count distributions in cohorts of fertile men from 1951 and 1971 to 1994. Sperm counts in fertile men have not changed appreciably in the 40 years since MacLeod's report.

Fertility↗
PubMed1998

Meiotic products of a Klinefelter 47,XXY male as determined by sperm fluorescence in-situ hybridization analysis.

The meiotic segregation of 24 spermatozoa obtained from a 47,XXY male is described. Three-colour fluorescence in-situ hybridization with probes for chromosomes X, Y and 18 was used. Five spermatozoa carried an X chromosome, seven carried a Y, six had an XY gonosomal complement, five were missing the sex chromosome and one spermatozoon was presumably diploid with an XX/1818 complement. Our results support the hypothesis that XXY cells are able to complete meiosis. In this patient, the percentage of spermatozoa with an abnormal number of sex chromosomes increased from 1/6 (17%) among spermatozoa with normal morphology to 11/18 (61%) in spermatozoa with abnormal morphology.

Chromosomes, Human, Pair 18↗
PubMed1997

The relationship of sperm counts to birth rates: a population based study.

PURPOSE: We determined if a statistical relationship exists between changes in sperm counts and birth rates by comparing data from a single geographic location for a 24-year period. MATERIALS AND METHODS: We retrospectively analyzed data from 660 men who banked 1,972 semen samples before vasectomy in Minnesota from 1971 to 1994. Using general linear models, annual variations in sperm count were determined after adjusting for age, duration of abstinence and seasonal (monthly) effects. Adjusted annual mean sperm count was then correlated with regional birth rate data obtained from The National Center for Health Statistics. RESULTS: Multiple regression analysis revealed a significant linear increase in mean annual sperm count at an estimated rate of 1.03 x 10(6) sperm per ml. per year (b = 0.14, t = 5.641, p < 0.0001). There was no effect of age (t = -0.814, p = 0.4156) but there were significant effects of abstinence (b = 0.14, t = 8.808, p < 0.0001) and month of sperm banking (b = 0.025, t = 5.00, p < 0.0001) on sperm counts. Using analysis of covariance there was a significant, nonlinear (year-to-year) fluctuation in mean sperm counts (F = 8.63, p < 0.001). For the study period mean birth rates in Minnesota (live births per 1,000 population) fluctuated yearly from 13.8 in 1973 to 16.7 in 1981. There was a strong correlation between adjusted mean yearly sperm count and annual birth rates (r = 0.63, p = 0.001). CONCLUSIONS: We found a statistically significant correlation between yearly variations in mean sperm counts and birth rates. Our data suggest that variations in male reproductive function may affect population based birth rates and, therefore, may be more important than previously understood.

Adult↗
PubMed1996

Abnormal sperm morphology is highly predictive of pregnancy outcome during controlled ovarian hyperstimulation and intrauterine insemination.

PURPOSE: The purpose of this study was to assess the predictive value of a modified form of Kruger's strict criteria for sperm morphology for pregnancy outcomes after intrauterine insemination (IUI) and controlled ovarian hyperstimulation (COH) in the presence of normal sperm concentration and motility. MATERIALS AND METHODS: A retrospective review of 42 couples undergoing COH/IUI was stratified by favorable or unfavorable sperm morphology. End points were pregnancy or failure of treatment as defined by four or more cycles of COH/ IUI without pregnancy. RESULTS: An unfavorable morphology (< 4%) was highly predictive of failure during COH-IUI (94.45%; 17/18). A normal PIF was a sensitive indicator of those patients who became pregnant (93.8%; 15/16) and had a fair specificity for failure to achieve pregnancy after four cycles of treatment (65.4%; 17/26). Couples with a favorable sperm morphology were 28.3 times as likely to achieve a pregnancy within four cycles of treatment as those with unfavorable sperm morphology [95% confidence limits, 3.2 to 250.5; P < 0.001]. CONCLUSIONS: Abnormal strict morphologic assessment is both sensitive and specific for pregnancy outcomes in couples undergoing COH/IUI. Couples with persistently unfavorable sperm morphology should be counseled appropriately and would be better served by more aggressive treatment with in vitro fertilization and embryo transfer.

Adult↗
PubMed1996

Semen analyses in 1,283 men from the United States over a 25-year period: no decline in quality.

OBJECTIVE: To determine whether semen quality has changed in the United States over the last 25 years. DESIGN: Retrospective review. SETTING: Three U.S. sperm banks, Cryogenic Laboratories, Inc. (Roseville, Minnesota), Idant Laboratories (New York, New York), and California Cryobank, Inc. (Los Angeles, California). INTERVENTION: None. MAIN OUTCOME MEASURES: Age at sample collection, sperm concentration, volume, motility, and days of abstinence before sample collection were determined for each man. Linear and multiple regression analyses were used to assess changes in these characteristics over time. RESULTS: Controlling for the effects of age and duration of abstinence, there was a slight but significant increase in mean sperm concentration but no change in either motility or semen volume over the 25-year period. Both sperm motility and semen volume decreased with increasing age at sample collection. Both sperm concentration and semen volume increased as a function of duration of abstinence. There were significant differences in mean (+/- SEM) sperm concentrations (10(6) sperm/mL) and motilities between the different sperm banks with California lowest (72.7 +/- 3.1, 51.4% +/- 1.1%, respectively), Minnesota higher (100.8 +/- 2.9, 56.0%, respectively), and New York highest (131.5 +/- 3.5, 58.2% +/- 0.5%, respectively). CONCLUSIONS: Our data show no decline in sperm counts over a 25-year period in 1,283 men who banked sperm before vasectomy at three distinct geographical sites in the United States.

Adult↗
PubMed1996

Geographic variations in sperm counts: a potential cause of bias in studies of semen quality.

OBJECTIVE: To determine whether geographic variations in sperm counts might bias conclusions drawn from studies of semen quality. DESIGN: Reanalysis of published data from a meta-analysis of 61 studies from 1938 to 1990 that concluded a worldwide decline in semen quality over the last 50 years. MAIN OUTCOME MEASURES: Influence of geographic location on sperm counts. RESULTS: Of 61 studies in the meta-analysis, only 20 included > or = 100 men. These 20 studies collectively comprised 91% of the total men studied. We focused our reanalysis on these 20 studies. Of the studies before 1970, all were from the United States and 80% were from New York. These studies represented locations with the highest sperm counts. In contrast, after 1970, 80% of the studies were from locations not represented earlier, including five studies from third world countries, where sperm counts were low. CONCLUSIONS: Sperm counts vary dramatically among different geographic locations.

Bias↗
PubMed1996

Accuracy of semen counting chambers as determined by the use of latex beads.

OBJECTIVE: To assess the accuracy of the Hemacytometer (Hausser Scientific, Horsham, PA), Makler (Sefi-Medical Instrument, Haifa, Israel), Cell-VU (Millennium Sciences Inc., New York, NY), and Micro-Cell chambers (Conception Technologies, San Diego, CA) counting chambers. DESIGN: A solution containing a known concentration of latex beads was used as the standard to perform counts on the four different counting chambers. MAIN OUTCOME MEASURES: Bead counts for the four different chambers were compared with the bead counts of the standard solution. Variability within chambers also was determined. RESULTS: Mean bead concentrations for both the Cell-VU and Micro-Cell chambers were consistently similar to the bead concentration of the standard solution. Both the hemacytometer and the Makler chambers overestimated the actual bead concentration of the standard solution by as much as 50% and revealed significant interchamber variability. CONCLUSIONS: Our data revealed marked differences in the accuracy and reliability of the different counting chambers tested and emphasized the need for standardization and quality control of laboratory procedures.

Humans↗
PubMed1996

Worldwide variations in sperm counts.

OBJECTIVES: Based on the premise that various human disease processes manifest differently depending on geography, we set out to determine whether sperm counts vary from different nations and different regions within the United States. METHODS: We reviewed the literature of all significant population-based studies that evaluated sperm counts from fertile or presumably fertile men from 1930 to the present. RESULTS: We found that sperm counts did, in fact, vary greatly. Throughout the United States, average sperm counts ranged from a low of 48 million/cc in lowa to a high of 134 million/cc in New York, with multiple values in-between from Texas, Minnesota, Washington State, and California. Internationally, average sperm counts ranged from a low of 52.9 million/cc in Thailand to a high of 102.9 million/cc in France. CONCLUSIONS: We conclude that sperm counts are subject to a wide range of variation among geographic locations.

Global Health↗
PubMed1995

Seminal vesicle urinary reflux as a complication of transurethral resection of ejaculatory ducts.

Transurethral resection of ejaculatory ducts has become an effective surgical treatment for male infertility caused by ejaculatory duct obstruction. We report on a patient treated successfully by transurethral resection of the ejaculatory ducts for a large midline cyst who postoperatively complained of terminal urinary dribbling lasting several minutes. On video urodynamic study reflux into and delayed drainage from the right seminal vesicle were found.

Adult↗