Search PubMed⌕ Search

Biomedical subjects

M Goldstein

Publications and source records attributed to M Goldstein.

At least 91 records · Page 5Linked to original sources
PubMed1998

Microsurgical vasovasostomy: the microdot technique of precision suture placement.

PURPOSE: A technique of vasovasostomy that facilitates precision suture placement is presented. MATERIALS AND METHODS: The technique involves mapping of the planned suture exit points with "microdots" placed on the cut ends of the vas deferens with a microtip marking pen. Microdots are placed at 12, 3, 6 and 9 o'clock positions. Four additional dots are placed between each of the previous 4 dots. Exactly 8 mucosal sutures (double armed 10-zero monofilament sutures) are used for each anastomosis. The anastomosis is completed with 8 muscularis sutures (9-zero monofilament) and 6 to 8 sutures (6-zero monofilament) approximating the vasal sheath. RESULTS: In a series of 194 consecutive vasovasostomy procedures using this technique a patency rate of 99.5% was achieved. Pregnancy rates of 54% (crude) and 64% (excluding female factor infertility) were observed for the first 100 subjects of this cohort. CONCLUSIONS: The microdot technique ensures precision suture placement and facilitates the anastomosis of lumens of discrepant diameters by exact mapping of each planned suture. The microdot method separates the planning from the placement. Patency rates using the microdot technique approach 100%.

Anastomosis, Surgical↗
PubMed1998

In vivo quantification of glucose uptake and conversion to glycogen in individual muscles of the rat following exercise.

Glycogen depletion is thought to be a potent stimulus for the substantially increased glucose fluxes observed in skeletal muscle following exercise. The aim of this study was to establish the relationships between the glycogen mass and the rates of glucose uptake (Rg') and glucose incorporation into glycogen (Rgly) in individual muscles of conscious adult Wistar rats following moderate nonexhausting treadmill exercise (15 m/min at a 10 degree slope for 45 minutes, approximately 65% VO2max). Muscle glycogen content was determined at 0, 20, 45, 90, or 135 minutes following exercise and compared with Rg' and Rgly measurements at matched times. Muscle types varied in the rate of glycogen resynthesis. Glycogen depots of glycolytic muscle (white gastrocnemius) were still significantly (P < .01) lower than preexercise levels after 135 minutes; red oxidative muscles (soleus and red gastrocnemius) were essentially repleted by 90 minutes. Immediately following exercise, Rg' and Rgly in red gastrocnemius and soleus were 42 +/- 4 and 42 +/- 5 and 36 +/- 2 and 33 +/- 7 micromol/(min . 100 g), greater than the rates induced by maximal insulin stimulation in previous studies. In red muscles, there was a strong inverse relationship between Rgly and tissue glycogen content, consistent with a dominant role for the glycogen mass in the regulation of glycogen resynthesis.

Animals↗
PubMed1998

Immunohistochemical studies on phosphorylation of tyrosine hydroxylase in central catecholamine neurons using site- and phosphorylation state-specific antibodies.

Antibodies raised to phosphorylated forms of tyrosine hydroxylase, the first and rate-limiting enzyme in the catecholamine biosynthesis, were applied in immunohistochemical studies on rat brain slices incubated in vitro with a phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine, IBMX) and on forskolin on formalin-perfused rat brains. Four antisera/antibodies were used: polyclonal rabbit antisera to (i) tyrosine hydroxylase phosphorylated at serine 40 (THS40p antiserum), (ii) tyrosine hydroxylase phosphorylated at serine 19 (THS19p antiserum), (iii) the native enzyme (pan-tyrosine hydroxylase antiserum), and mouse monoclonal antibody to (iv) native tyrosine hydroxylase. In the in vitro studies THS40p-like immunoreactivity was not observed unless slices were treated with IBMX-forskolin after which a dense fibre network was found in the striatum, and immunoreactive cell bodies were found in the ventral mesencephalon, especially in the ventral tegmental area. Although these cells were pan-tyrosine hydroxylase-positive, several of them were not stained with the tyrosine hydroxylase-monoclonal antibody. Moreover, there was a marked reduction of tyrosine hydroxylase-monoclonal antibody-immunoreactive fibres in drug-treated slices, suggesting that this tyrosine hydroxylase-monoclonal antibody does not recognize the serine 40-phosphorylated form of tyrosine hydroxylase. Treated slices did not show any THS40p-immunoreactive cell bodies in the dopaminergic A11 cell group and only a few, weakly fluorescent neurons were observed in locus coeruleus. However, a sparse fibre plexus was observed in locus coeruleus, possibly reflecting epinephrine fibres. In the perfused brains THS40p-like immunoreactivity could be visualized in some dopamine neurons in the ventral mesencephalon, especially the A10 area, and in noradrenergic locus coeruleus neurons, whereas THS19p-like immunoreactivity was found in all catecholamine groups studied, similar to the results obtained with the pan-tyrosine hydroxylase antiserum and the tyrosine hydroxylase-monoclonal antibody. In forebrain areas known to be innervated by mesencephalic dopamine neurons, no THS40p-positive fibres were observed, whereas THS19p-immunoreactive fibres were found in subregions of the striatum, olfactory tubercle and nucleus accumbens, essentially overlapping with dopamine fibres previously shown to contain cholecystokinin-like immunoreactivity. The present results suggests that antibodies directed against phosphorylated forms of tyrosine hydroxylase can be used to evaluate the state of tyrosine hydroxylase phosphorylation in individual neuronal cell bodies and processes both in vitro and in vivo.

1-Methyl-3-isobutylxanthine↗
PubMed1998

Capsular bag distension associated with sulcus implantation of intraocular lenses.

Capsular bag distension syndrome after endophacoemulsification and in-the-bag intraocular lens (IOL) implantation has been reported. We describe 2 cases in which sulcus implantation of a posterior chamber IOL caused marked capsular bag distension. Both cases resolved with conservative treatment or a neodymium:YAG posterior capsulotomy.

Aged↗
PubMed1998

Effects of galanin on dopamine release in the central nervous system of normotensive and spontaneously hypertensive rats.

Galanin is a 29-amino acid peptide and widely distributed in the brain, although its significance in the control of neural activities is undefined. In the present study, we describe the effects of galanin on the electrically evoked release of dopamine in the rat central nervous system. In addition, to elucidate a possible role of galanin in the regulation of dopaminergic transmission in hypertension, we examined whether the effect of galanin on dopamine release might be altered in the central nervous system of spontaneously hypertensive rats (SHR). Galanin (1 x 10(-8) to 1 x 10(-7) mol/L) inhibited the stimulation (1 Hz)-evoked [3H]dopamine release by a comparable amount in striatal slices of Sprague-Dawley rats, although the basal release of dopamine was not affected by the peptide. In the striatum of SHR, the electrical stimulation (1 Hz)-evoked [3H]dopamine release was significantly smaller than in the striatum of Wistar-Kyoto (WKY) rats. However, the inhibitory effect of galanin on the stimulation-evoked [3H]dopamine release was significantly more pronounced in SHR than in WKY rats. These results show that galanin significantly reduced the release of dopamine in rat striatum. Furthermore, the greater inhibitory effect of galanin on dopamine release in SHR suggests that galanin might actively participate in the regulation of dopaminergic nerve activity in hypertension.

Animals↗
PubMed1998

Role of serine-19 phosphorylation in regulating tyrosine hydroxylase studied with site- and phosphospecific antibodies and site-directed mutagenesis.

The effects of depolarization by elevated potassium concentrations were studied in PC12 cells and in stably transfected AtT-20 cells expressing wild-type or [Leu19]-recombinant tyrosine hydroxylase (rTH). Changes in the phosphorylation states of Ser19 and Ser40 in tyrosine hydroxylase (TH) were determined immunochemically using antibodies specific for the phosphorylated state of each site and compared with changes in TH activity in PC12 cell lysates and with changes in L-DOPA biosynthesis rates in intact AtT-20 cells. Treatment of either PC12 cells or AtT-20 cells expressing wild-type rTH with elevated potassium produced a transient increase in the phosphorylation state of Ser19 (up to 0.7 mol of phosphate/mol of subunit) in concert with a more gradual and sustained increase in Ser40 phosphorylation. Elevated potassium treatment also increased TH activity in PC12 cell lysates, but these increases paralleled the temporal course of Ser40, as opposed to Ser19, phosphorylation. Similarly, increases in DOPA accumulation produced by elevated potassium in AtT-20 cells expressing wild-type rTH paralleled the increases in the phosphorylation state of Ser40 but not Ser19. Moreover, elevated potassium produced comparable increases in DOPA accumulation in AtT-20 cells expressing rTH in which Ser19 phosphorylation had been eliminated (by substitution of Leu for Ser19). Thus, depolarization-induced increases in the stoichiometry of Ser19 phosphorylation do not appear to influence directly the activity of TH in situ.

Amino Acid Substitution↗
PubMed1998

Preoperative screening for genetic abnormalities in men with nonobstructive azoospermia before testicular sperm extraction.

PURPOSE: Men with nonobstructive azoospermia may be treated with testicular sperm extraction and assisted reproduction. However, in men with severely impaired spermatogenesis genetic anomalies may be a cause of low sperm production. We present the results of genetic screening of men with nonobstructive azoospermia who are testicular sperm extraction candidates. MATERIALS AND METHODS: Genetic evaluation was performed in a sequential series of 190 men with nonobstructive azoospermia who were candidates for testicular sperm extraction, including standard peripheral karyotypic analysis and detailed polymerase chain reaction based evaluation of the Y chromosome. All men found to harbor genetic defects were referred for genetic counseling. RESULTS: Of the 190 patients 33 (17%) had genetic abnormalities. Of the 101 men who underwent karyotyping 21 (21%) had cytogenetic abnormalities, including 13 with Klinefelter's syndrome. Of the 183 men who underwent Y chromosome partial deletion analysis defects were detected in 17 (9%). Five men had karyotypic anomalies as well as evidence of partial Y chromosome deletions on polymerase chain reaction based analysis. Genetic counseling was done in 31 men with defects before testicular sperm extraction. Knowledge of the specific genetic defect resulted in a change of clinical management in 7 of the 33 couples (21%) in which the man had a genetic abnormality. CONCLUSIONS: These results indicate that preoperative genetic screening is important in men with nonobstructive azoospermia who are candidates for testicular sperm extraction with intracytoplasmic sperm injection. Genetic testing provides men with reassuring etiological information regarding the infertile condition as well as a means to assess the risk of passing infertility traits to male offspring. It allows specific preimplantation genetic testing of embryos during assisted reproduction to minimize the risk of transmitting genetic defects to offspring.

Chromosome Aberrations↗
PubMed1998

Benign fat necrosis simulating bilateral breast malignancy after reduction mammoplasty.

Fat necrosis follows many forms of trauma to the breast, including surgery. In unusual cases, it may be extensive enough to present as a palpable mass on physical examination with mammographic features suggestive of cancer. In these instances, regardless of patient age, surgical history, or multifocality, a biopsy must be done to exclude carcinoma. We describe a young woman who was evaluated for bilateral breast masses with highly suspicious imaging characteristics 2 years after having reduction mammoplasty.

Adult↗
PubMed1998

Captopril inhibits both dopaminergic and cholinergic neurotransmission in the central nervous system.

1. The present study was performed to investigate the effects of captopril on both dopaminergic and cholinergic neurotransmission in the rat central nervous system. 2. Slices of rat striatum were prepared and prelabelled with [3H]-dopamine or [3H]-choline. Slices were continuously superfused with Krebs'-Ringer solution and electrical stimulation (1 Hz) was performed. 3. Captopril significantly inhibited stimulation-evoked [3H]-dopamine release from rat striatal slices in a concentration-dependent manner (S2/S1 ratios: control 0.835 +/- 0.018 (n = 6); 1 x 10(-5) mol/L captopril 0.597 +/- 0.035 (n = 6; P < 0.05); 5 x 10(-5) mol/L captopril 0.561 +/- 0.041 (n = 6; P < 0.05)). However, the basal release of [3H]-dopamine was not affected by captopril. 4. Captopril also reduced stimulation-evoked [3H]-acetylcholine release in the striatum (S2/S1 ratios: control 0.891 +/- 0.016 (n = 6); 1 x 10(-5) mol/L captopril 0.794 +/- 0.011 (n = 6; P < 0.05)). 5. These results show that captopril inhibits the release of both dopamine and acetylcholine in the rat striatum. Although the mechanisms underlying the neurosuppressive effects of captopril remain to be determined, the findings suggest that the inhibition of dopaminergic and cholinergic neurotransmission may be related to the central action of the angiotensin-converting enzyme inhibitor.

Acetylcholine↗
PubMed1998

The diagnostic interview schedule for deaf patients on interactive video: a preliminary investigation.

OBJECTIVE: The authors investigated the feasibility of translating the National Institute of Mental Health Quick Diagnostic Interview Schedule-III, Revised, computer version, for deaf individuals. METHOD: The study involved translation of selected scales into American Sign Language, Signed English, and speech reading; review by an advisory panel and back translator; and collection and analysis of deaf individuals' reactions to translations. RESULTS: Focus groups responded favorably, translation problems were revealed, and solutions were suggested. CONCLUSIONS: The findings support the feasibility of translation of the Quick Diagnostic Interview Schedule-III, Revised, into American Sign Language, Signed English, and speech reading for deaf patients.

Adolescent↗
PubMed1998

Urban crack users: gender differences in drug use, HIV risk and health status.

This study assessed gender differences in drug use, HIV risk, and health status in a sample of urban crack users. Using targeted sampling, 1434 crack users (66% male and primarily African-American and Puerto Rican), were recruited from the streets of East Harlem, New York City. A standardized, structured interview was administered, drug use was validated by urinalysis, and HIV testing was offered. Gender differences were observed on sociodemographic variables and patterns of drug use. Other than welfare, men and women cited different major sources of income. Women reported greater use of crack, and men were more likely to use injection drugs as well as crack. Data on sexual risk indicated that women had more sexual partners than men, but the percentage of unprotected vaginal sex for both men and women was greater for those who did not exchange sex for drugs and/or money. The number of persons already infected with HIV was substantial. Many reported histories of other sexually transmitted diseases which were generally higher among men. Future research should investigate the relationship between gender and other factors (e.g., ethnicity, geographic location) associated with HIV risk.

Adult↗
PubMed1998

A specimen positioning device for dental radiographic identification--image geometry considerations.

Preventative dental treatment has reduced caries incidence and thereby rendered dental identification, in caries-free individuals, more difficult. An alternate method comparing spatial relationships of dental structures in digitized superimposed antemortem and postmortem radiographs has been previously developed. This paper examined the limitations of this technique and demonstrates a positioning device suitable for reproducing antemortem radiographic image geometry. The paper also examined three specific aspects of image geometry namely horizontal angulation, vertical angulation and focal film distance. Deviations in horizontal angulations between antemortem and postmortem radiographs by as little as 5 degrees makes identification difficult. Changes in vertical angulation or focal-film distance had no affect. This procedure, and the positioning device used to accurately replicate antemortem image geometry is an economical, easy to use adjunct to current methods of dental identification.

Autopsy↗
PubMed1998

Morphometric and electron-microscopic analyses of the effects of gonadotropin-releasing hormone agonists on uterine leiomyomas.

OBJECTIVE: Reports on the histologic effects of gonadotropin-releasing hormone agonists on uterine leiomyomas provide conflicting results. Most previous studies used qualitative methods of analysis. Using quantitative and semiquantitative stereologic methods of analysis, we assessed volume density of hyalinized areas, cell density, nuclear volume, and cytoplasmic cross-sectional areas of smooth muscle cells in histologic sections and also measured diameters of collagen fibrils in electron micrographs of uterine leiomyomas. DESIGN: Thirty leiomyomas from patients treated with gonadotropin-releasing hormone agonists (10 different patient samples), age-matched control patients (10 different patient samples), and postmenopausal women (10 different patient samples) were used. Hyalinization was assessed using a microscope with a projection head and affixed morphometric grid. Cell size and density were evaluated using a video-based, computerized system attached to the microscope, for which morphometric ad hoc programs were written. Diameters of collagen fibrils were measured from electron micrographs. SETTING: The study was conducted in the Department of Pathology, Mount Sinai Medical Center, New York, NY. PATIENTS: A total of 30 patient samples were studied, with three groups comprising 10 samples each, including patients treated with gonadotropin-releasing hormone agonists, age-matched control patients, and postmenopausal women. RESULTS: Myomas from patients treated with gonadotropin-releasing hormone agonists exhibited more hyalinization, greater cell density, slightly smaller cell sizes, and larger collagen fibrils than those of age-matched control patients and postmenopausal women. CONCLUSIONS: Shrinkage after treatment with gonadotropin-releasing hormone agonists is attributed to smaller cell size and increased collagenization in myomas.

Adult↗
PubMed1998

Microsurgical repair of the adolescent varicocele.

PURPOSE: Since clinically apparent varicoceles may affect testicular volume and sperm production, early repair has been advocated. However, repair of the pediatric varicocele with conventional nonmagnified techniques may result in persistence of the varicocele after up to 16% of these procedures. Also testicular artery injury and postoperative hydrocele formation can occur after nonmagnified repair. The microsurgical technique has been successfully completed in a large series of adults with a dramatic reduction in complication and recurrence rates. We report our experience with the microsurgical technique in boys. MATERIALS AND METHODS: A total of 30 boys (average age 15.9 years) underwent 42 microsurgical varicocelectomies (12 bilateral). All patients had a large left varicocele. Indications for repair included testicular atrophy (size difference between testicles of greater than 2 ml.) in 20 boys, pain in 5 and a large varicocele without pain or testicular atrophy in 5. Six boys were referred following failure of conventional nonmicrosurgical techniques. All boys were examined no sooner than 1 month postoperatively (mean followup 12). RESULTS: Preoperative volume of the affected testis averaged 13.0 ml., and an average size discrepancy between testicles of 2.8 ml. was noted before unilateral varicocelectomy. No cases of persistent or recurrent varicoceles were detected, and 1 postoperative hydrocele resolved spontaneously. After unilateral varicocelectomy the treated testes grew an average of 50.1%, while the contralateral testes grew only 23%. Overall, 89% of patients with testicular atrophy demonstrated reversal of testicular growth retardation after unilateral varicocelectomy. In contrast, both testes showed similar growth rates after bilateral varicocelectomy (45% left testis, 39% right testis). CONCLUSIONS: The meticulous dissection necessary to preserve arterial and lymphatic supply, and to ligate all spermatic veins in the pediatric patient is readily accomplished using a microsurgical approach, and results in low recurrence and complication rates. Rapid catch-up growth of the affected testis after microsurgical varicocelectomy suggests that intervention during adolescence is effective and warranted.

Adolescent↗
PubMed1997

A multisite study of sexual orientation and injection drug use as predictors of HIV serostatus in out-of-treatment male drug users.

The risk groups of men who have sex with men and injection drug users (IDUs) together account for 90% of all male AIDS cases. The extent to which each risk behavior contributes to seroprevalence among IDUs has not been determined and is critical for intervention development. Analysis of data on sexual orientation, injection drug use, and HIV serostatus was undertaken in a multisite study of 3002 male drug injectors and crack smokers recruited for HIV prevention projects. Overall HIV seroprevalence was 8.4%; 57.1% for gay men, 25.4% for bisexual men, and 7.4% for heterosexuals (p = 0.001). Logistic regression analyses indicated being gay (OR = 24.08) and coming from an area where seroprevalence is high among IDUs (OR = 4.07) were the best predictors of serostatus. Ever having injected was significant only in interaction with moderate (OR = 3.09) or high (OR = 4.71) IDU seroprevalence areas. Among this multisite sample of drug users, being a gay drug user is the strongest predictor of serostatus. Drug injection is significant only in areas of moderate or high seroprevalence among injectors. This indicates the importance of targeted outreach and intervention efforts.

Adult↗
PubMed1997

Modulation of [3H]dopamine release by neuropeptide Y in rat striatal slices.

Neuropeptide Y, a 36-amino-acid peptide, has a wide and specific distribution in the central nervous system. In this study we examined the regulatory mechanisms of neuropeptide Y on dopamine release in the rat central nervous system. The effects of neuropeptide Y on the electrically stimulated [3H]dopamine release were investigated in superfused striatal slices of Sprague-Dawley rats, spontaneously hypertensive rats and Wistar-Kyoto rats. Neuropeptide Y (1 x 10(-8) - 1 x 10(-7) mol/1) reduced the stimulation (1 Hz)-induced [3H]dopamine release by a comparable amount in Sprague-Dawley rats. The blockade of dopamine D2 receptors by the dopamine D2 receptor antagonist, sulpiride, diminished the inhibitory effects of neuropeptide Y on the stimulation-evoked [3H]dopamine release. Pretreatment of slices with pertussis toxin (a potent inhibitor of G1-proteins) attenuated the suppression of the stimulation-evoked [3H]dopamine release by neuropeptide Y. Unlabelled dopamine itself reduced the stimulation-evoked [3H]dopamine release, and the inhibitory effect was also attenuated in the pertussis toxin-pretreated slices. In spontaneously hypertensive rats, the inhibitory effect of neuropeptide Y on the stimulation-evoked [3H]dopamine release was more pronounced than that in Wistar-Kyoto rats. The results of the present study showed that neuropeptide Y inhibited the stimulation-evoked dopamine release partially mediated by dopamine D2 receptors and the pertussis toxin-sensitive G1-proteins in rat striatum. Furthermore, the greater effect of neuropeptide Y on dopamine release in spontaneously hypertensive rats suggests a possible involvement of the peptide in regulating the central dopaminergic nerve activity in hypertension.

Animals↗