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Biomedical subjects

M A Cohen

Publications and source records attributed to M A Cohen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Role of sonography in evaluation of radial scars of the breast.

OBJECTIVE: We investigated the usefulness of sonography in revealing radial scars suspected on mammography. CONCLUSION: Many radial scars are visible on sonography and, when visible, may present features virtually identical to those of carcinoma of the breast. Findings indicative of a radial scar are often more conspicuous on sonography than on mammography; thus, sonography may have a definitive role when evaluating subtle findings suggestive of a radial scar or when features of a radial scar are evident on only one mammographic view and cannot be localized with certainty.

Aged↗
PubMed2000

The effect of treating forages with fibrolytic enzymes on its nutritive value and lactation performance of dairy cows.

Forages (corn silage and alfalfa hay) were sprayed with liquid enzymes prior to combining with a concentrate to form a total mixed ration (50% forage:50% concentrate, dry matter basis) and fed to lactating cows. In the first year, treatments were 1) no enzymes, 2) an enzyme complex containing 3500 carboxymethyl cellulase (CMCase) and 16,000 xylanase units per kilogram of forage dry matter, or 3) an enzyme complex containing 8800 CMCase units and 40,000 xylanase units. In the second year, the treatments were 1) no enzymes, 2) an enzyme complex as in yr 1 containing 3700 CMCase and 14,000 xylanase units, or 3) an enzyme complex using an alternative cellulase and containing 3600 CMCase and 11,000 xylanase units. In the first year, cows fed diet 2 tended to produce more milk (39.5 kg/d) than those fed diet 1 (37.0 kg/d) or those fed diet 3 (36.2 kg/d). The high level of enzyme treatment in diet 3 decreased the output of milk protein and fat compared to the low level of enzyme treatment. In the second year, cows fed diet 3 produced more milk (35.4 kg/d) than did those fed diet 1 (32.9 kg/d) and numerically more than those fed diet 2 (33.6 kg/d). Milk fat and protein were similar among treatments but numerically lower for cows fed enzyme-treated forages. Dry matter intake (kg/d) was similar among treatments in both years. Spraying certain doses and combinations of enzymes directly onto forages prior to feeding can improve milk yields but enzyme sources and dose levels are of critical importance.

Animal Nutritional Physiological Phenomena↗
PubMed2000

Latex sensitivity in Washington State acute care hospitals. A needs assessment and survey of awareness of the issues.

Based on reports from the workers' compensation system and a sentinel health provider network, latex gloves may be one of the most prevalent sources of occupational skin disorders in Washington State's health care industry. To gather information to understand and address this problem, questionnaires were distributed to 105 acute care hospitals in Washington State. Employee health and infection control specialists were queried on their knowledge about latex allergy, the perceived extent of the problem, and the actions taken to address the problem. With 95 of the hospitals returning completed questionnaires (93% response rate), 30% reported having problems with latex allergies among employees in their facility, with most reporting two or fewer cases. Adequate knowledge was found about the causes and effects of latex allergies, but definite knowledge gaps existed. More than 60% of all of the hospitals surveyed had made some type of glove alternatives available to affected employees, 4% had designated latex free zones, 4% had cleaned to remove latex dust, and 7% had done nothing to address the issue.

Data Collection↗
PubMed1999

The role of essential pyrimidines in the hairpin ribozyme-catalysed reaction.

The hairpin ribozyme is an example of a small catalytic RNA that catalyses the endonucleolytic transesterification of RNA in a highly sequence-specific manner. We have utilised chemical synthesis of RNA to create mutants of the hairpin ribozyme in which a nucleoside analogue replaces one of the essential pyrimidines in the ribozyme. Individual pyrimidine nucleosides were substituted by 4-thiouridine, O4-methyluridine, O2-methyluridine or 2-pyrimidinone-1-beta-d-riboside. To facilitate the synthesis of oligoribonucleotides containing 4-thiouridine, we have devised a new synthetic route to the key intermediate 5'-O-(4, 4'-dimethoxytrityl)-2'-O-tert-butyldimethylsilyl-S-cyanoethyl-4-thiou ridine. The ability of the modified ribozymes to support catalysis was studied and the steady-state kinetic parameters were determined for each mutant. The range of analogues used in this study allows the important functional groups of the essential pyrimidines to be identified. The results demonstrate that each pyrimidine (U41, U42 and C25) plays an important role in hairpin ribozyme catalysis. The findings are discussed in terms of the various models that have been proposed for loop B of the hairpin ribozyme.

Kinetics↗
PubMed1999

21-hydroxylase deficiency and Turner's syndrome: a reason for diminished endometrial receptivity.

OBJECTIVE: To report a case of cryptic 21-hydroxylase deficiency identified at the time of ovum donation in a patient with Turner's syndrome. DESIGN: Case report. SETTING: University IVF practice. PATIENT(S): A 28-year-old woman with Turner's syndrome who presented for ovum donation. INTERVENTION(S): Four cycles of donor IVF. MAIN OUTCOME MEASURE(S): Pregnancy, endometrial appearance, progesterone, and 17-hydroxyprogesterone values. RESULT(S): The patient failed two fresh and two frozen ET cycles with donated oocytes. The appearance of the endometrium suggested elevated progesterone before progesterone supplementation. An elevated progesterone was detected but not suppressed by leuprolide acetate. Progesterone was suppressed by adding dexamethasone. The diagnosis of cryptic 21-hydroxylase deficiency was confirmed biochemically. CONCLUSION(S): Patients with Turner's syndrome reportedly have poorer outcomes with donor IVF than other women. They also have an increased incidence of carrying a defective 21-hydroxylase gene. We suggest that some of the poorer outcomes may be explained by the presence of elevated progesterone and recommend evaluation of possible congenital adrenal hyperplasia in patients with Turner's syndrome who want oocyte donation.

Adrenal Hyperplasia, Congenital↗
PubMed1999

Ultrasound guided embryo transfer significantly improves pregnancy rates in women undergoing oocyte donation.

OBJECTIVES: Recent reports suggest ultrasound (US) guided embryo transfer (ET) improves pregnancy rates. Using the ovum donation model to eliminate confounding variables, we assessed the impact of US guided ET on pregnancy rates, implantation rates, and multiple gestation rates. METHODS: All women who underwent IVF-ET cycles using donated oocytes from November 1997 to September 1998 (n = 137) were evaluated retrospectively. ET from November 1997 to April 1998 were performed without US, while all ET from May 1998 to September 1998 were performed using transvaginal or transabdominal US. ET was further categorized as easy or difficult. Difficult ET was defined as requiring at least two attempts and/or the presence of blood on the catheter and/or > 5 min. RESULTS: Pregnant patients (n = 73) were similar with respect to the number and morphology of the embryos transferred compared to non-pregnant patients (n = 65). US guidance significantly improved implantation and pregnancy rates in cycles with easy transfers [28.8 vs. 18.4% and 63.1 vs. 36.1%, respectively (P < 0.05)] without impacting multiple pregnancy rates. CONCLUSION: US guided ET is simple and reassuring and appears to significantly improve pregnancy outcomes in ovum donation cycles by optimizing the placement of embryos.

Adult↗
PubMed1999

Activity of clinafloxacin, trovafloxacin, quinupristin/dalfopristin, and other antimicrobial agents versus Staphylococcus aureus isolates with reduced susceptibility to vancomycin.

Isolations of Staphylococcus aureus strains with reduced susceptibility to vancomycin are now being reported worldwide. In testing here by broth microdilution according to NCCLS guidelines and applying vancomycin breakpoint criteria (susceptible at 4 micrograms/mL), two of three strains were susceptible (MICs at 4 micrograms/mL) rather than intermediate (MICs at 8 micrograms/mL) as previously reported by other laboratories. Clinafloxacin was more active (MICs/MBCs at 0.5 to 2 micrograms/mL) than ciprofloxacin, grepafloxacin, levofloxacin, ofloxacin, and sparfloxacin. Trovafloxacin, trimethoprim/sulfamethoxazole, and quinupristin/dalfopristin were the next most active agents, although quinupristin/dalfopristin was bactericidal against only two of these three strains. Amikacin, imipenem, oxacillin, and rifampin were less active.

Anti-Bacterial Agents↗
PubMed1999

Acute suppurative parotitis with spread to the deep neck spaces.

This report describes the case of an elderly, diabetic woman who became dehydrated and developed acute suppurative parotitis, which caused marked swelling of her left face and neck. The parotid infection also extended by continuity into the lateral pharyngeal space and contiguous deep neck spaces, causing airway-threatening, extensive inflammation and swelling of the epiglottis and parapharyngeal soft tissues. The differential diagnosis and diagnostic rationale is discussed. The anatomy of the stylomandibular area is reviewed to explain how infection of the parotid can spread to the pharynx.

Acute Disease↗
PubMed1999

Serum progesterone before and after human chorionic gonadotropin injection depends on the estradiol response to ovarian hyperstimulation during in vitro fertilization-embryo transfer cycles.

PURPOSE: Our purpose was to assess if periovulatory serum progesterone is reflective of ovarian responsiveness in controlled ovarian hyperstimulation (COH). METHODS: One-hundred forty-two in vitro fertilization-embryo transfer cycles in women using GnRH-a suppression and human menopausal gonadotropin (hMG) stimulation were evaluated. Responses were studied according to ovarian response to hMG and age. Outcome measures included peak serum estradiol, serum progesterone and estrogen/progesterone ratios on the day of hCG injection, number of harvested oocytes, fertilization rates, and delivered pregnancy rates. RESULTS: A periovulatory rise in serum progesterone (> 0.9 ng/ml) occurred only among younger women (< 40 years old) with a good response (P < 0.05). Though the number of oocytes was greater in good responders, fertilization and pregnancy rates were similar among all women regardless of age and ovarian response. CONCLUSIONS: Periovulatory levels of serum progesterone vary according to ovarian response to COH. Elevations in progesterone do not appear to be a manifestation of poor responders. Reduced periovulatory progesterone may reflect inadequate steroidogenesis.

Adult↗
PubMed1999

Reproductive outcome after sterilization reversal in women of advanced reproductive age.

OBJECTIVE: Our objective was to assess the clinical outcome of tubal reversal in women of advanced reproductive age. METHODS: A multicenter retrospective chart review of 153 patients who underwent a tubal ligation reversal was carried out. Patients were evaluated according to age. All patients had documented ovulation and a partner with a normal semen analysis by WHO criteria. Outcome measures included rates of clinical pregnancy, ectopic pregnancy, spontaneous abortion, and live birth, and the time to conception. RESULTS: Clinical pregnancy rates were significantly lower in women > or = 40 compared to younger groups. The time to conception was significantly shorter for women < 30 compared to women > or = 35. No pregnancies occurred in women > or = 42. CONCLUSIONS: Our data support the judicious use of sterilization reversal for infertile women with no male factor through their early forties. Women > or = 42 years should be especially counseled as to the very low success rates.

Adult↗
PubMed1999

Donor age is paramount to success in oocyte donation.

Several reports suggest increasing age in oocyte donors decreases the chances of in-vitro fertilization (IVF) success, while others describe no effect. The published data concerning gravidity and parity are similarly conflicting. To further address these questions, we retrospectively studied 445 consecutive donor IVF cycles at two large university-based IVF practices. Donor cycles were analysed for the number of oocytes retrieved, gravidity, parity, and age of the donor, and pregnancy outcome in recipients. The previous gravidity and parity of the donor were not associated with successful pregnancy in recipients. The number of oocytes retrieved was positively correlated with pregnancy. However, after adjusting for donor age, neither prior fertility nor the number of oocytes retrieved were significant predictors. In contrast, the donor's age was highly associated with recipient success. We conclude that the age of the oocyte donor is a significant predictor of pregnancy success and should be a major factor in selecting prospective candidates. The gravidity and parity of the donor are insignificant predictors, as are the total number of oocytes retrieved at the time of oocyte harvest.

Adult↗
PubMed1999

Hydrosalpinges adversely affect implantation in donor oocyte cycles.

Hydrosalpinges have been associated with poor in-vitro fertilization (IVF) outcome in some, but not all, studies, perhaps through endometrial effects. To determine whether hydrosalpinges affect IVF outcome via endometrial factors alone, we analysed the results of recipients of donor oocytes with hydrosalpinges, thereby controlling for confounding variables, while isolating the intrauterine environment. We retrospectively analysed 110 patients who underwent 121 donor oocyte cycles in a university-based assisted reproduction programme. Thirteen cycles involving recipients (n = 10) with hydrosalpinges were compared to 108 cycles involving recipients (n = 100) without hydrosalpinges. Pregnancy, implantation, miscarriage, and ectopic pregnancy rates were compared between women with and without hydrosalpinges. There were no significant differences between the hydrosalpinx and no hydrosalpinx groups with respect to donor age, recipient age, or number or grade of embryos transferred. Patients with a hydrosalpinx had significantly lower embryo implantation rates (7.1 versus 19.3%, P < 0.05) and significantly higher miscarriage (75.0 versus 14.9%, P < 0.05) and ectopic pregnancy rates (33.3 versus 0.0%, P < 0.05) than normal controls. We conclude that the presence of a hydrosalpinx adversely affects early pregnancy events by altering the intrauterine environment.

Fallopian Tube Diseases↗
PubMed1999

Peptides as drugs.

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Anti-Bacterial Agents↗