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Biomedical subjects

M Goldstein

Publications and source records attributed to M Goldstein.

At least 73 records · Page 4Linked to original sources
PubMed1999

Comparison of absorbable and nonabsorbable sutures for microsurgical vasovasostomy in rats.

OBJECTIVES: At least 12% of initially patent vasovasostomies (VVs) shut down. Currently, only nonabsorbable sutures are used for VV. A synthetic, slowly absorbing, monofilament polyglactin suture has been developed that retains tensile strength for up to 6 months. We performed a prospective controlled randomized study comparing absorbable and nonabsorbable sutures for rat VVs. METHODS: Bilateral microsurgical VV was performed in three groups of 36 Wistar male rats, with 10-0 nylon, 10-0 polypropylene, and 10-0 polyglactin sutures. Twelve control rats underwent sham operations. Three rats in each group were killed at 2, 6, 12, and 24 weeks. The abdominal end of the vas deferens was transected and the intraluminal fluid examined microscopically for presence of sperm. The segment of the vas deferens containing the anastomosis was excised. Fluid from the testicular end was examined for sperm to confirm spermatogenesis. Patency was confirmed by an antegrade indigo carmine vasogram of the anastomotic segment. Segments were randomly sent for histologic or tensile strength evaluation. RESULTS: The mean tensile strength of the anastomoses performed with nylon was slightly higher than in polypropylene and polyglactin sutures, although the difference was not statistically significant. Polyglactin consistently maintained tensile strength throughout 6 months without significant fluctuations. The mean patency rate in the polyglactin group was 96%, in nylon 81%, and in polypropylene 61%. Although polyglactin had a consistently higher patency rate compared with nonabsorbable sutures, the difference was not statistically significant (P = 0.11) but indicated a strong trend. The occurrence of microscopic sperm granuloma, muscle layer injuries, intimal fibrosis, and adventitial fibrosis of the vas deferens was not significantly different between suture types. CONCLUSIONS: The three suture materials appear equivalent with respect to overall tensile strength of anastomosis; with histologic evaluation, the trend was toward better patency with polyglactin. Polyglactin 10-0 microsurgical suture is a viable alternative to nonabsorbable sutures in microsurgical VVs, although further studies are indicated to assess long-term results.

Animals↗
PubMed1999

Retinal vein occlusion associated with methylenetetrahydrofolate reductase mutation.

OBJECTIVE: To report on the occurrence of methylenetetrahydrofolate reductase (MTHFR) deficiency in patients with retinal vein occlusion (RVO). DESIGN: Prospective case series PARTICIPANTS: Fifty-nine consecutive patients with newly diagnosed RVO seen at the Retina Unit in the Tel Aviv Medical Center during 1997. METHODS/TESTING: Interviews and multiple blood analyses were done. Data were compared to the reported incidence of MTHFR deficiency in the Israeli population at large. RESULTS: Twenty-six patients (44.1%) were heterozygotes and 11 (18.6%) were homozygotes for 677C-T mutation in MTHFR. The MTHFR 677C-T homozygosity was documented as being present in 10.4% of healthy individuals in the Israeli population. The difference in homozygosity was found to be statistically significant (P = 0.038). CONCLUSIONS: Retinal vein occlusion may be associated with a mutation in MTHFR.

Adult↗
PubMed1999

On the distribution patterns of D1, D2, tyrosine hydroxylase and dopamine transporter immunoreactivities in the ventral striatum of the rat.

The distribution of dopamine D1 and D2 receptor immunoreactivities in the nucleus accumbens and the olfactory tubercle of adult and postnatal male rats were compared with the distribution of tyrosine hydroxylase and dopamine transporter immunoreactivities. An overall co-distribution of D1 and D2 receptor immunoreactivities with tyrosine hydroxylase immunoreactivity was found in the nucleus accumbens and the olfactory tubercle. However, the major finding in this study was, following a more detailed analysis in coronal sections of the shell part of the nucleus accumbens, the existence of nerve cell patches of strong D1 receptor immunoreactivity associated with low D2 receptor, dopamine transporter and tyrosine hydroxylase immunoreactivities. These patches were mainly surrounded by areas of strong D2 receptor, tyrosine hydroxylase and dopamine transporter immunoreactivities and could be found also in the olfactory tubercle. Similar observations were made in postnatal rats. Serial reconstructions of the patches of strong D1 receptor immunoreactivity in the rostrocaudal direction were made. The patches formed a continuous tubular nerve cell system in the shell part of the nucleus accumbens. Since this nerve cell system was found to be surrounded by a high density of dopamine terminals, it may represent a compartment where dopamine transmission mainly acts on D1 receptors via local diffusion (i.e. via volume transmission). However, it must be noted that the D1 receptor rich patches constitute only a small fraction of the nucleus accumbens and the overall density of tyrosine hydroxylase immunoreactive terminals correlates with the density of both D1 and D2 receptors in the nucleus accumbens. In conclusion, the present paper gives new aspects on the chemical microarchitecture of the nucleus accumbens.

Aging↗
PubMed1999

The effects of antitumor irradiation on mandibular opening and mobility: a prospective study of 58 patients.

OBJECTIVE: The purpose of this study was to analyze the effects of head and neck radiation therapy on jaw opening and mobility. STUDY DESIGN: Maximum jaw opening and mandibular mobility were measured before and after radiation treatment in 58 patients presenting for angle down wedge, homolateral wedge pair, and parallel pair head and neck radiation treatment. RESULTS: As dose to the temporomandibular joint and pterygoid muscles increased, maximal jaw opening decreased linearly. Mandibular dysfunction appeared to increase as radiation dose to the pterygoid muscles increased. Similar effects were not observed with temporomandibular joint irradiation. Irradiation of the pterygoid muscles appeared critical in the development of trismus. Angle down wedge treatment irradiated the temporomandibular joint and pterygoid muscles with clinical effects similar to those seen in homolateral wedge pair and parallel pair patients. Doses as low as 1493 cGy resulted in functional impairment. CONCLUSIONS: Future investigations into radiotherapy delivery and appropriate postradiation trismus treatment may reduce head and neck radiation morbidity.

Analysis of Variance↗
PubMed1999

Pulsatile ocular blood flow in diabetic retinopathy.

PURPOSE: To assess circulatory properties of eyes with progressive stages of diabetic retinopathy. METHODS: The intraocular pressure, pulse amplitude (PA) and pulsatile ocular blood flow (POBF) were measured with a pneumatonometer (OBF Labs UK Ltd). The eyes were grouped: (a) normal control, n = 26, (b) diabetes with no observable diabetic retinopathy (NDR), n = 18, (c) mild to moderate non-proliferative diabetic retinopathy (NPDR), n = 20, and (d) very severe pre-proliferative and proliferative diabetic retinopathy (PPDR/PDR), n = 12. RESULTS: The PA and POBF values were lower than normal values in the earliest stage (NDR). The POBF increased but was still below normal levels at the NPDR stage, and then increased to an above normal level in the PPDR/PDR stage of diabetic retinopathy. The PA was at normal levels in these later two stages. CONCLUSION: An initial decrease in pulsatile ocular blood flow is present with the onset of diabetes where no diabetic retinopathy has yet occurred. Subsequently, the pulsatile ocular blood flow increases with the severity of the retinopathy.

Aged↗
PubMed1999

Cilioretinal artery occlusion during coronary catheterization.

PURPOSE: To report on a patient with cilioretinal artery occlusion during cardiac catheterization. METHODS: A 51-year-old man complained of blurred vision in the left eye immediately following cardiac catheterization. Visual acuity was 6/12 and the eye had a dense central scotoma. RESULTS: Mild retinal whitening of the posterior pole and segmented filling of the cilio-retinal artery established the diagnosis of cilioretinal artery occlusion. Immediate paracentesis was performed. Two weeks later, a tiny central scotoma could be observed and visual acuity was 6/6. CONCLUSIONS: Cardiac catheterization may result in retinal infarction. Awareness to any visual symptoms, immediate diagnosis and prompt intervention may prevent permanent visual impairment.

Cardiac Catheterization↗
PubMed1999

Valacyclovir inhibits recovery of ocular HSV-1 after experimental reactivation by excimer laser keratectomy.

PURPOSE: The goal of this was to determine whether the systemic administration of valacyclovir (Valtrex) would reduce ocular shedding of herpes simplex virus 1 (HSV-1) after excimer laser ablation in the New Zealand rabbit latency model. METHODS: The in vitro 50% inhibitory concentration (IC50) of HSV-1 W strain was determined by using a plaque-reduction assay to verify its sensitivity to acyclovir. Forty-seven NZW rabbits latently infected with HSV-1 W strain were divided into four groups: I, 50 mg/kg/day valacyclovir; II, 100 mg/kg/day valacyclovir; III, 150 mg/kg/day valacyclovir; and IV, saline control. One half of the total dose of valacyclovir was delivered via intraperitoneal injections twice daily for 7 days beginning with one dose before excimer laser keratectomy. HSV-1 ocular shedding was determined from eye cultures for 7 days after treatment. RESULTS: The IC50 for HSV-1 W was determined to be 2.9 microg/ml. The administration of both 100 mg/kg/day (group II) and 150 mg/kg/day (group III) of valacyclovir significantly reduced the number of eyes from which latent HSV-1 was recovered compared with the control group. There was no difference between the control group and group I (50 mg/kg/day valacyclovir). However, all three valacyclovir dosages significantly reduced the total number of HSV-1 shedding days compared with the control group, and 100% HSV-1 TG latency was demonstrated for all four groups. CONCLUSION: Systemic administration of valacyclovir significantly reduced HSV-1 ocular shedding in a dose-dependent manner after excimer laser keratectomy in the NZW rabbit latency model.

Acyclovir↗
PubMed1999

Comparison of bilateral versus unilateral varicocelectomy in men with palpable bilateral varicoceles.

PURPOSE: The left varicocele is usually larger in men with bilateral varicoceles. We hypothesized that most of the benefit of varicocelectomy would derive from repair of the larger varicocele. To test this hypothesis we prospectively compared the effect of unilateral versus bilateral microsurgical varicocelectomy in men with large (grade III) or moderate (II) left varicocele associated with small but palpable (I) right varicocele. MATERIALS AND METHODS: A total of 91 patients were prospectively followed and included in the study. Of the patients 65 underwent bilateral and 26 underwent unilateral left repair. All patients underwent preoperative and postoperative semen analysis. RESULTS: Motile sperm concentration increased from 12.1+/-1.7 to 23.7+/-31.8 (95.8% change) in the bilateral group compared with an increase from 19.5+/-21.4 to 27.8+/-34.8 (42.6% change) in the unilateral group (p<0.05). Similarly, sperm concentration increased from 23.8+/-29.5 to 48.6+/-61.3 (157.6% change) in the bilateral group compared with an increase from 41.1+/-40.9 to 59.5+/-66.7 (44.8% change) in the unilateral group (p<0.05). CONCLUSIONS: Bilateral varicocelectomy resulted in significantly greater improvement in post-operative seminal parameters than unilateral repair in patients with grades II to III left varicocele associated with grade I right varicocele. Even a small, unrepaired palpable right varicocele continues to have a detrimental effect on bilateral testis function. Men with bilateral palpable varicoceles require bilateral repair.

Adult↗
PubMed1999

Increased site-specific phosphorylation of tyrosine hydroxylase accompanies stimulation of enzymatic activity induced by cessation of dopamine neuronal activity.

Activation of striatal dopamine (DA) neurons by neuroleptic treatment or by electrical stimulation of the nigrostriatal pathway increases the activity of tyrosine hydroxylase (TH). The increase is mediated by phosphorylation of the enzyme. However, abolition of DA neuronal activity [by gamma-butyrolactone (GBL) treatment or transection of the nigrostriatal pathway] also increases TH activity. Quantitative blot immunolabeling experiments using site- and phosphorylation state-specific antibodies to TH demonstrated that GBL treatment (750 mg/kg, 35 min) significantly increased phosphorylation at Ser19 (+40%) and Ser40 (+217%) without altering Ser31 phosphorylation. Concomitantly, GBL treatment [along with the 3,4-dihydroxyphenylalanine (dopa) decarboxylase inhibitor NSD-1015, 100 mg/kg, 30 min] increased in vivo striatal dopa accumulation and in vitro TH activity 3-fold. Likewise, cerebral hemitransection of the nigrostriatal pathway significantly increased phosphorylation of TH at Ser19 (+89%) and Ser40 (+158%) but not at Ser31; dopa levels were increased accordingly (+191%). Kinetic analysis of TH activity established that GBL treatment and hemitransection primarily decreased the Km for the cofactor tetrahydrobiopterin (3-fold). The effects of GBL and hemitransection were abolished or attenuated by pretreatment with the DA agonist R-(-)-N-n-propylnorapomorphine (NPA; 30 microgram/kg, 40 min), presumably via stimulation of inhibitory presynaptic DA autoreceptors. NPA dose-response curves for reversal of GBL-induced dopa accumulation and Ser40 phosphorylation were identical; however, only the highest dose of NPA reversed the small and variable increase in Ser19 phosphorylation. Thus, TH activity seems to be regulated by phosphorylation in both hyper- and hypoactive striatal DA neurons; in the latter case, activation seems to be caused by selective phosphorylation of Ser40.

4-Butyrolactone↗
PubMed1999

Antibacterial skin preparation decreases the incidence of false-positive semen culture results.

PURPOSE: Antibacterial skin preparation was used before obtaining semen cultures to assess whether true seminal pathogens could be isolated with greater specificity. MATERIALS AND METHODS: A total of 14 paired semen cultures were obtained from men evaluated for infertility. The first set (group 1) was obtained without preparation and the second set (group 2) was obtained after using an antibacterial skin preparation consisting of a shower followed by perineal, penile and hand wash with 4% chlorhexidine and 10% povidone-iodine. The sets were compared and statistical analysis was performed using the paired t test. RESULTS: In group 1, 25 total bacterial isolates were detected compared to 13 in group 2, which was statistically significant (p <0.002). In group 1, 11 enteric organisms were isolated compared to 5 in group 2, which was also statistically significant (p <0.05). These data suggest that the source of most enteric organisms isolated from semen is genital and perineal skin. CONCLUSIONS: A significant reduction in enteric contaminants, which would otherwise be erroneously treated, can be achieved with an effective antibacterial skin preparation. We were able to isolate true pathogens with greater specificity with (80%) than without (63%) an antibacterial skin preparation. An antibacterial skin preparation reduces false-positive cultures by at least 50%, which would lead to a significant reduction in costs and morbidity.

Administration, Cutaneous↗
PubMed1999

Testicular sperm extraction with intracytoplasmic sperm injection for nonobstructive azoospermia: testicular histology can predict success of sperm retrieval.

PURPOSE: We present treatment results of testicular sperm extraction with intracytoplasmic sperm injection for men with nonobstructive azoospermia and reevaluate the role of testicular histology on open diagnostic testicular biopsy as a predictor of sperm retrieval success. MATERIALS AND METHODS: We evaluated 75 men diagnosed with nonobstructive azoospermia. Cases were categorized into 3 groups of hypospermatogenesis, maturation arrest or Sertoli-cell-only based on the most advanced pattern of spermatogenesis seen on histology. A total of 81 testicular sperm extractions with intracytoplasmic sperm injection were performed for these 75 men. The main outcome measures reviewed included sperm retrieval, fertilization and pregnancy rates with intracytoplasmic sperm injection. Sperm retrieval success rates for men in the 3 histological categories were compared. RESULTS: Spermatozoa were successfully retrieved during 47 of 81 (58%) testicular sperm extraction attempts, with subsequent fertilization of 268 of 439 (61%) injected metaphase II oocytes using intracytoplasmic sperm injection. Clinical pregnancies were obtained in 26 of 47 (55%) cycles when sperm were retrieved, with ongoing pregnancies or live deliveries for 20 of 47 (43%). Of 39 men with hypospermatogenesis on diagnostic biopsy 31 (79%) had successful sperm retrieval, compared to 9 of 19 (47%) with maturation arrest and 5 of 21 (24%) with a pure Sertolicell-only pattern. CONCLUSIONS: Critical examination of the most advanced pattern of spermatogenesis from open diagnostic testis biopsy allows prediction of sperm retrieval success with testicular sperm extraction. In this study population spermatozoa were retrieved in 58% of attempts. When this testicular sperm was used with intracytoplasmic sperm injection, clinical pregnancy rate was 55% for men with nonobstructive azoospermia.

Adult↗
PubMed1999

The effects of mesh bioprosthesis on the spermatic cord structures: a preliminary report in a canine model.

PURPOSE: The use of mesh bioprosthesis during inguinal herniorrhaphy is now considered routine. To our knowledge, no studies have examined the effects of mesh induced fibrosis on the structure and function of the adjacent spermatic cord. We present our experience in a canine model. MATERIALS AND METHODS: Unilateral inguinal hernia defects were created in 12 male beagle dogs. Half were repaired using Marlex mesh and half using a classic Shouldice technique. The inguinal anatomy was then re-examined at 6 and 12 months. Testicular temperature and volume, peripheral and testicular vein testosterone levels, testicular blood flow, vasography, testicular and cord histology, and sperm motility/morphology were recorded. Groups were compared with each other as well as to the non-operated (control) side. RESULTS: Although post-operative testicular volumes from both the mesh and Shouldice groups were similar to controls (p >0.05), there was a downward trend after mesh repair (17.8 cc pre versus 12.6 cc post) but this did not reach statistical significance (p = 0.17). Testicular temperatures and blood flow did not differ between experimental groups and controls. While testicular vein testosterone levels were significantly higher than peripheral venous levels after Shouldice repair, this difference was lost after mesh repair. Contralateral (control) testicular vein testosterone levels were higher in animals repaired with mesh than by an anatomic Shouldice repair (p <0.05). There was a significant decrease in cross sectional vasal luminal diameter in both the anatomic and mesh repair groups versus their respective contralateral controls (p <0.05). This was correlated with a marked foreign body reaction to the mesh in the soft tissues surrounding the vas in spermatic cords exposed to Marlex. All vasograms demonstrated patency. Gross pathology was abnormal in 3/6 dogs with mesh repair (2 hydroceles and 1 ischemic testis) and 0/6 animals after Shouldice repair. A traumatic neuroma was identified in the mesh group. Sperm morphology and motility did not differ between the two groups. CONCLUSIONS: Half of the testicles had gross abnormalities after mesh repair versus none in the control and Shouldice dogs. Although all vasograms were patent, vasal luminal size was significantly decreased with a marked soft tissue foreign body reaction identified after mesh repair. A traumatic neuroma was identified suggesting nerve entrapment in the fibrotic mesh reaction, which may account for post-operative pain seen in some patients. Marlex mesh may adversely affect spermatic cord structure and function and further work is required to fully elucidate its effects.

Animals↗
PubMed1999

Efficacy of jejunogram after jejunostomy insertion.

The era of managed care has spawned a national debate over the allocation of health care resources. We hypothesized that routine postjejunostomy jejunogram rarely provides additional clinical information or changes patient management and, therefore, is unwarranted. We retrospectively reviewed the charts of 128 consecutive patients undergoing feeding jejunostomy tube insertion between January 1995 and December 1996. All patients had postinsertion jejunograms. Eighty-five (66%) of the jejunograms were performed after operative insertion of the jejunostomy, and 43 (33%) were performed after percutaneous reinsertion of a previously placed jejunostomy. Data extracted from the charts include age, sex, indication for jejunogram, length of time prior jejunostomy was in place at time of reinsertion, and results of jejunogram. There were no patients (0%) with misplaced jejunostomy or extravasation of dye, as noted on jejunogram. There were no management changes implemented as a result of jejunogram readings (P < <0.05). The use of routine jejunogram after operative insertion or reinsertion of a prior jejunostomy that has become dislodged or occluded does not alter patient management, incurs unnecessary costs, and, therefore, is unwarranted.

Adolescent↗
PubMed1998

The RET/PTC3 oncogene: metastatic solid-type papillary carcinomas in murine thyroids.

Our research goal is to better understand the mechanisms controlling the initiation and progression of thyroid diseases. One such disease, papillary thyroid carcinoma (PTC), is the leading endocrine malignancy in the United States. Recently, a family of related fusion proteins, RET/PTC1-5, has been implicated in the early stages of PTC. Although all five members of this family have the c-RET proto-oncogene kinase domain in their COOH terminus, little is known about how these genes alter follicular cell biology. Consequently, to answer questions related to the mechanism of the RET/PTC fusion protein action, we have devised a molecular genetic strategy to study PTC using a mouse model of thyroid disease. A new member of this fusion oncogene family, RET/PTC3, which has been implicated in more cases of solid tumor carcinoma (79%) than PTC1 or PTC2 and predominates (80%) in radiation-induced thyroid cancer of children, was investigated in our study. We have generated transgenic mice expressing human RET/PTC3 exclusively in the thyroid. These mice develop thyroid hyperplasia, solid tumor variants of papillary carcinoma and metastatic cancer. This new transgenic line will be useful in deciphering the molecular and biological mechanisms that cause PTC and histological variations in humans.

Animals↗
PubMed1998

Induction of spermatogenesis and achievement of pregnancy after microsurgical varicocelectomy in men with azoospermia and severe oligoasthenospermia.

OBJECTIVE: To characterize treatment outcome after varicocele repair in men with azoospermia and severe oligoasthenospermia. DESIGN: Prospective nonrandomized study. SETTING: University-based medical center. PATIENT(S): Seventy-eight men with a palpable varicocele and absolute azoospermia (n = 22) or severe oligoasthenospermia (n = 56). INTERVENTION(S): Microsurgical varicocelectomy. MAIN OUTCOME MEASURE(S): Sperm count and pregnancy rate. RESULT(S): Twelve (55%) of the 22 men with azoospermia and 35 (69%) of the 51 men with zero motile sperm before surgery had motile sperm observed in their ejaculate after varicocele repair. The total number of motile sperm per ejaculate increased from 0.08 +/- 0.02 x 10(6) before varicocelectomy to 7.2 +/- 2.3 x 10(6) afterward. Twenty-four men (31%) contributed to pregnancies leading to live births (15 unassisted [19%]), including 3 men with azoospermia preoperatively. CONCLUSION(S): Varicocele repair resulted in the induction or enhancement of spermatogenesis for most men with azoospermia or severe oligoasthenospermia. Unassisted pregnancies after varicocele repair in men with profound abnormalities of spermatogenesis are possible. Varicocele repair should be considered for all men with azoospermia and severe oligoasthenospermia.

Female↗
PubMed1998

Microsurgical repair of iatrogenic injury to the vas deferens.

PURPOSE: We determined the incidence of iatrogenic injuries to the vas deferens at a tertiary care university infertility center and the results of surgical repair. MATERIALS AND METHODS: Records of 472 patients surgically explored for obstructive azoospermia between 1984 to 1996 were reviewed. Enrollment criteria included history of inguinal, pelvic and scrotal (other than vasectomy) surgery. Conventional ipsilateral and crossover vasovasostomies and vasoepididymostomies were performed. Patency rate was defined as presence of complete sperm with tails in a postoperative semen analysis. Followup included a minimum of 2 semen analyses. Only naturally conceived pregnancies were included. RESULTS: Of 472 patients 34 (7.2%) had an iatrogenic injury to the vas deferens with a mean obstruction interval of 20.5 +/- 1.9 years. Mean patient age was 36.7 +/- 1.8 years. Iatrogenic injury to the vas deferens was secondary to bilateral inguinal hernia repair in 19 patients, unilateral hernia repair in 11, renal transplantation in 2, appendectomy in 1 and spermatocelectomy in 1. Pediatric inguinal hernia repair was the most common etiology of the vasal injury (20 patients), followed by adult inguinal hernia repair (10). A total of 36 microsurgical reconstructive procedures were performed, including 20 ipsilateral and 16 crossed vasovasostomies and vasoepididymostomies. There were 26 patients (29 procedures) available for followup (mean 21.0 +/- 3.7 months). Total patency rate per procedure was 65% and pregnancy rate was 39%. Patency and pregnancy rates per conventional ipsilateral procedures were 62.5 and 35.7% and per crossover procedures 64.2 and 42.8%, respectively. CONCLUSIONS: Pediatric inguinal hernia repair is the most common cause of iatrogenic injury to the vas deferens. Results of treatment of iatrogenic injury to the vas deferens are somewhat lower than for patients with obstructive azoospermia due to vasectomy. Iatrogenic injuries are associated with longer vasal defects, impaired blood supply and longer obstructive intervals frequently resulting in secondary epididymal obstruction. Crossover reconstruction is particularly useful when contralateral testicular atrophy is present. Intraoperatively aspirated sperm should be cryopreserved for later use in case the reconstruction fails.

Adult↗