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Allen Seftel

Publications and source records attributed to Allen Seftel.

At least 19 recordsLinked to original sources
PubMed2006

Meiotic recombination and spatial proximity in the etiology of the recurrent t(11;22).

Although balanced translocations are among the most common human chromosomal aberrations, the constitutional t(11;22)(q23;q11) is the only known recurrent non-Robertsonian translocation. Evidence indicates that de novo formation of the t(11;22) occurs during meiosis. To test the hypothesis that spatial proximity of chromosomes 11 and 22 in meiotic prophase oocytes and spermatocytes plays a role in the rearrangement, the positions of the 11q23 and 22q11 translocation breakpoints were examined. Fluorescence in situ hybridization with use of DNA probes for these sites demonstrates that 11q23 is closer to 22q11 in meiosis than to a control at 6q26. Although chromosome 21p11, another control, often lies as close to 11q23 as does 22q11 during meiosis, chromosome 21 rarely rearranges with 11q23, and the DNA sequence of chromosome 21 appears to be less susceptible than 22q11 to double-strand breaks (DSBs). It has been suggested that the rearrangement recurs as a result of the palindromic AT-rich repeats at both 11q23 and 22q11, which extrude hairpin structures that are susceptible to DSBs. To determine whether the DSBs at these sites coincide with normal hotspots of meiotic recombination, immunocytochemical mapping of MLH1, a protein involved in crossing over, was employed. The results indicate that the translocation breakpoints do not coincide with recombination hotspots and therefore are unlikely to be the result of meiotic programmed DSBs, although MRE11 is likely to be involved. Previous analysis indicated that the DSBs appear to be repaired by a mechanism similar to nonhomologous end joining (NHEJ), although NHEJ is normally suppressed during meiosis. Taken together, these studies support the hypothesis that physical proximity between 11q23 and 22q11--but not typical meiotic recombinational activity in meiotic prophase--plays an important role in the generation of the constitutional t(11;22) rearrangement.

Chromosomes, Human, Pair 11↗
PubMed2006

Synaptic defects at meiosis I and non-obstructive azoospermia.

BACKGROUND: Recent advances in immunofluorescence methodology have made it possible to directly monitor protein localization patterns in germ cells undergoing meiosis. We used this technology to examine the early stages of meiosis in testicular material obtained from men presenting for evaluation at infertility clinics. METHODS: Specifically, we compared meiotic progression, synapsis and recombination in 34 individuals with obstructive azoospermia ('controls') to 26 individuals with non-obstructive azoospermia (NOA) ('cases'). RESULTS: In 9 of the 26 cases, no germ cells were identified, but in the remaining 17, there was at least some progression through meiosis. Most of these individuals appeared to have normal levels of spermatogenic activity, with little evidence of meiotic impairment. However, in three individuals, we observed either complete or partial meiotic arrest associated with abnormalities in synapsis. CONCLUSIONS: This suggests that >10% of cases of unexplained NOA may be attributable to severe meiotic defects. The characterization of these meiotic arrest phenotypes may guide further research into the molecular basis of unexplained infertility.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Sexual dysfunction and prostatitis.

Despite a large number of reports exploring the links between diseases of the prostate and effects on sexuality, the relationship between prostatitis and sexual dysfunction has not been as thoroughly investigated. A number of reports have focused on the adverse effects of prostatitis on quality of life, with resultant indirect effects on sexuality. More detailed studies are available on the links between ejaculation and the chronic prostatitis/chronic pelvic pain syndrome subgroup of prostatitis. Improvement of sexual dysfunction following treatment of prostatitis has been reported in a few studies, most notably in association with alpha-blocker therapy. This review addresses some of the more relevant reported links between prostatitis and sexual function.

Humans↗
PubMed2006

Erectile dysfunction--an observable marker of diabetes mellitus? A large national epidemiological study.

PURPOSE: We examined whether men with erectile dysfunction are more likely to have diabetes mellitus than men without erectile dysfunction, and whether erectile dysfunction can be used as an observable early marker of diabetes mellitus. MATERIALS AND METHODS: Using a nationally representative managed care claims database from 51 health plans and 28 million members in the United States, we conducted a retrospective cohort study to compare the prevalence rates of diabetes mellitus between men with erectile dysfunction (285,436) and men without erectile dysfunction (1,584,230) during 1995 to 2001. Logistic regression models were used to isolate the effect of erectile dysfunction on the likelihood of having diabetes mellitus with adjustment for age, region and 7 concurrent diseases. RESULTS: The diabetes mellitus prevalence rates were 20.0% in men with erectile dysfunction and 7.5% in men without erectile dysfunction. With adjustment for age, region and concurrent diseases, the odds ratio of having diabetes mellitus between men with erectile dysfunction and without erectile dysfunction was 1.60 (p <0.0001). With adjustment for regions and concurrent diseases, the age specific odds ratios ranged from 2.94 (p <0.0001, age 26 to 35) to 1.05 (p = 0.1717, age 76 to 85). CONCLUSIONS: Men with erectile dysfunction were more than twice as likely to have diabetes mellitus as men without erectile dysfunction. Erectile dysfunction is an observable marker of diabetes mellitus, strongly so for men 45 years old or younger and likely for men 46 to 65 years old, but it is not a marker for men older than 66 years.

Adolescent↗
PubMed2005

Meiotic synapsis proceeds from a limited number of subtelomeric sites in the human male.

The formation of the synaptonemal complex (SC) is a crucial early step in the meiotic process, but relatively little is known about the establishment of the human SC. Accordingly, we recently initiated a study of synapsis in the human male, combining immunofluorescence and fluorescence in situ hybridization methodologies to analyze prophase spermatocytes from a series of control individuals. Our results indicate that synapsis is a tightly regulated process, with relatively little variation among individuals. On nonacrocentric chromosomes, there are two synaptic initiation sites, one on the distal short arm and one on the distal long arm, whereas acrocentric chromosomes exhibit a single site on the distal long arm. For both types of chromosomes, synapsis then proceeds toward the centromere, with little evidence that specific p- or q-arm sequences affect the process. However, the centromere appears to have an inhibitory effect on synapsis--that is, when one arm of a nonacrocentric chromosome is "zippered up" before the other, the centromere acts as a barrier to further movement from that arm.

Adult↗
PubMed2005

The costs of caring for erectile dysfunction in a managed care setting: evidence from a large national claims database.

PURPOSE: We examined the direct costs of erectile dysfunction (ED) empirically. MATERIALS AND METHODS: A naturalistic cohort study was done in 285,436 patients with ED and 51 health plans that covered 28 million lives nationwide from 1999 through 2001. Based on claims that had an ED related diagnosis code, procedure code or medication code we categorized the cost structure of ED care and calculated the annual costs of ED care per patient with ED, per user and per member monthly for individual and for all categories of ED care. RESULTS: A patient with ED in a health plan spent about an average of 83.91 dollars in 1999, 95.41 dollars in 2000 and 119.26 dollars in 2001 for ED care. In 2001, 37.08% of ED care costs per patient with ED were spent on phosphodiesterase type 5 (PDE-5) inhibitor therapy, 14.36% were spent on physician office visits, 10.19% were spent on diagnosis procedures, 8.45% were spent on testosterone hormone therapy, 3.85% were spent on penile prosthesis implantation, 4.41% were spent on intracavernous injection, 2.68% were spent on alprostadil pellet insertion and 0.81% was spent on vacuum erection devices. Of the 7 commonly used ED treatments PDE-5 inhibitor therapy has the lowest annual cost per user. CONCLUSIONS: In 2001 ED imposed a 122,669 dollars annual burden to a health plan with 100,000 members, that is or 0.108 dollars per member monthly. Each patient with ED spent 119.26 dollars annually for all ED related services or treatments. Of the 7 commonly used treatments PDE-5 inhibitor therapy had the lowest annual cost per user.

Adolescent↗
PubMed2005

The efficacy of tadalafil in clinical populations.

OBJECTIVES: To evaluate the efficacy of tadalafil in men with erectile dysfunction (ED) by demographic and ED characteristics, in patients having various comorbid medical conditions, and in patients receiving drug treatment for other medical conditions. METHODS: This is an analysis of 11 double-blind, placebo-controlled trials with 2,102 men with a broad spectrum of ED etiology and various comorbid medical conditions as participants. The variables analyzed in this report included race, age, body mass index (BMI), ED etiology, ED severity, ED duration, smoking, prior sildenafil use, presence of comorbid conditions (diabetes mellitus, hypertension, cardiovascular disease, hyperlipidemia, depression, benign prostatic hyperplasia), and treatment with antihypertensives or antidepressants. Patients were randomly assigned to receive tadalafil 10 mg (N=321), tadalafil 20 mg (N=1,143), or placebo (N=638). The primary efficacy variables included mean changes from baseline in the erectile function (EF) domain score of the International Index of Erectile Function (IIEF) questionnaire, and the mean per-patient percentage of "yes" responses to the Sexual Encounter Profile (SEP) diary question 3 (SEP3--successful intercourse). The Global Assessment Question 1 (GAQ) was evaluated, as was the percentage of men attaining a normal IIEF EF domain score at end point. RESULTS: Patients taking tadalafil 10 mg or 20 mg demonstrated significant improvement (P<0.005) from baseline to end point on the IIEF EF domain score in all subpopulations analyzed compared with patients receiving placebo. The mean-per-patient percentage of "yes" responses to SEP3 increased significantly in all subpopulations taking tadalafil compared with placebo (P<0.05). Tadalafil-treated patients had a significantly greater positive response rate on the GAQ in all subpopulations analyzed compared with placebo-treated patients (P<0.03) except for the tadalafil 10 mg cardiovascular subpopulation (placebo, 46.8%; tadalafil 10 mg, 71.0%; P=0.127). The percentage of positive responses ranged from 72% to 91% for patients on tadalafil 20 mg and from 52% to 94% for tadalafil 10 mg compared with a range of 20% to 47% for placebo-treated patients. CONCLUSIONS: Tadalafil was effective in improving erectile function across a wide spectrum of ED patients including patients with various comorbid conditions.

Adult↗
PubMed2005

Attitudes of men with erectile dysfunction: a cross-national survey.

INTRODUCTION: Erectile dysfunction (ED), the inability to achieve or maintain an erection sufficient for sexual performance, is a complex disorder involving multiple biopsychosocial factors. AIM: To better understand the psychological and behavioral aspects of ED and compare the attitudes of ED patients in different countries. METHODS: The Cross-National Survey on Male Health Issues surveyed men aged 20-75 years in six countries. Participants completed questionnaires on attitudes, behavior, doctor-related issues, and comorbidities. MAIN OUTCOME MEASURES: Men rated their attitudes using a scale of 1 (strongly disagree) to 5 (strongly agree). Responses of "somewhat agree" and "strongly agree" were combined and the percentage calculated for each country and overall. A mean score for all responses (1-5) was calculated for each country. RESULTS: Attitudes held by men with ED overlap significantly when compared between countries. Men in all countries agreed that ED was a source of great sadness for themselves and their partners, and nearly all disagreed with the idea that they were too old for sex. Men in all countries agreed that it was important to know they had the capacity to perform sexually, and half of all men reported they would do "nearly anything" to cure their ED. Men in all countries also agreed that their doctor was the best source of information on sexual issues. Men in the United States and the United Kingdom were less willing to accept ED, more motivated to find a cure, and less likely to consider ED a result of psychological problems. CONCLUSIONS: Attitudes of men with ED overlap significantly when compared between countries, but interesting differences were seen. Additional research is needed to understand how attitudes and behaviors reported reflect actual experiences. This study highlights some of the barriers that exist between physician-patient communication surrounding identification and treatment of ED.

Adult↗