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Biomedical subjects

M J Levy

Publications and source records attributed to M J Levy.

At least 37 records · Page 2Linked to original sources
PubMed1998

The adverse effect of hydrosalpinges on in vitro fertilization pregnancy rates and the benefit of surgical correction.

OBJECTIVE: To test the hypothesis that IVF-ET pregnancy rates (PRs) for patients with tubal factor infertility are decreased in patients with hydrosalpinges and that surgical correction reverses this effect. DESIGN: Retrospective chart review. SETTING: Private practice IVF-ET program. PATIENT(S): Patients (n = 160) undergoing 238 cycles of IVF-ET were stratified into groups based on the presence of hydrosalpinges and whether surgical correction had been performed. Patients >39 years old and patients with male factor infertility were excluded from the study. INTERVENTION(S): Patients with hydrosalpinges were offered surgical correction. MAIN OUTCOME MEASURE(S): Clinical pregnancy defined by an intrauterine gestational sac. RESULT(S): Patients with hydrosalpinges had significantly decreased implantation rates and PRs per transfer (2.8% and 8.5%, respectively) than patients with tubal factor infertility but without hydrosalpinges (15.7% and 38.6%). Surgical correction improved implantation rates and PRs in patients with prior failed cycles (16.1% and 37.5%) and in patients undergoing surgery before IVF-ET (21.8% and 51.7%). The type of surgery performed did not affect success rates in the small number of patients evaluated. CONCLUSION(S): The presence of a hydrosalpinx during an IVF-ET cycle results in significant decreases in implantation rates and PRs. Surgical treatment of hydrosalpinges before IVF-ET cycles improves implantation rates and PRs.

Adult↗
PubMed1997

Comparison of omeprazole and ranitidine for stress ulcer prophylaxis.

Stress ulcer prophylaxis protects against clinically important gastrointestinal bleeding and has gained widespread use. This study compares the efficacy of omeprazole to ranitidine for this indication. This was a prospective, randomized clinical trial. Sixty-seven high-risk patients were randomized to receive either ranitidine 150 mg (N = 35) intravenously daily or omeprazole 40 mg (N = 32) daily orally or by nasogastric route. Patients were monitored for clinically important bleeding. There was no statistically significant difference between treatment groups in the number of patients enrolled, gender, race, or age. The study groups were comparable in regard to the severity of illness based on their similar APACHE II score, duration of ICU stay, duration of ventilator dependence, and mortality rate. A significant difference was found only in regard to the number of risk factors per patient. The ranitidine-treated group had 2.7 risk factors per patient while the omeprazole-treated group had 1.9 (P < 0.05). Eleven patients (31%) given ranitidine and two patients (6%) given omeprazole developed clinically important bleeding (P < 0.05). Nosocomial pneumonia developed in five patients (14%) receiving ranitidine and one patient (3%) receiving omeprazole (P > 0.05). We conclude that oral omeprazole is safe, effective, and clinically feasible for stress ulcer prophylaxis.

APACHE↗
PubMed1996

The effect of angiotensin II on myosin heavy chain expression in cultured myocardial cells.

Angiotensin II (AII), the principal mediator of the renin-angiotensin system, is an important regulator of vascular and cardiac homeostasis. AII has also been shown to be a regulator of cardiac hypertrophy and of the corresponding changes in amount and composition of certain tissue proteins. We examined the trophic effects of AII on cultured myocytes derived from neonatal rat ventricles and followed, by Northern blot analysis and polyacrylamide gel electrophoresis, the expression of alpha- and beta-myosin heavy chain iso-mRNAs and isoproteins. Our findings show that a single administration of AII is sufficient to induce a trophic response in cultured beating myocytes and to enhance the expression of beta-myosin heavy chain iso-mRNA and isoprotein, having no effect on alpha-myosin heavy chain. Induction of alpha-myosin heavy chain expression by thyroid hormone before AII was administered showed that AII could not potentiate a shift from alpha- to beta-myosin heavy chain predominance. We suggest that the potency of AII to regulate the expression of myosin heavy chain isogenes is restricted to the beta isoform and is overridden by thyroid hormone.

Angiotensin II↗
PubMed1995

The predictive value of serum progesterone and 17-OH progesterone levels on in vitro fertilization outcome.

PURPOSE: In order to identify parameters which predict prognosis for success with in vitro fertilization, 17-hydroxyprogesterone and progesterone levels were evaluated in 254 patients undergoing 296 in vitro fertilization cycles. Selected response and outcome data were recorded. RESULTS: Patients with intermediate values of serum progesterone (0.7-0.8 ng/ml) at the time of human chorionic gonadotropin administration achieved significantly higher pregnancy rates than patients with lower (< 0.7 ng/ml) or higher (> 0.8 ng/ml) levels. The clinical pregnancy rates were 46%, 31%, and 27% respectively (P = 0.02). There was no change in 17-hydroxyprogesterone concentration which predicted a higher pregnancy rate. CONCLUSION: Excellent clinical pregnancy rates were noted in cycles with a progesterone level of 0.7-0.8 ng/ml, as well as good results in cycles above 0.8 ng/ml. There is therefore no reason to administer human chorionic gonadotropin at a smaller follicle size to prevent a rise in serum progesterone.

17-alpha-Hydroxyprogesterone↗
PubMed1995

Prognostic value of day 3 estradiol on in vitro fertilization outcome.

OBJECTIVE: To evaluate the prognostic value of day 3 E2 levels, independent of day 3 FSH levels, on responses to ovulation induction and subsequent pregnancy rates (PRs) in IVF-ET patients. DESIGN: Prospective, observational. SETTING: University-based tertiary care and private reproductive endocrine-infertility units. PATIENTS AND INTERVENTIONS: A total of 225 patients underwent 292 IVF cycles with luteal phase GnRH agonist suppression and hMG stimulation. MAIN OUTCOME MEASURES: We evaluated response and outcome data including age, day 3 FSH and E2 levels from a menstrual cycle before IVF, ampules of hMG used, maximum E2 level, cancellation rates, and clinical PR. RESULTS: Despite similar age, number of ampules of hMG, and peak E2 levels, patients with an elevated E2 level (E2 > or = 80 pg/mL) (conversion factor to SI unit, 3.671) on day 3 of a cycle before IVF-ET achieved a lower PR per initiated cycle (14.8% versus 37.0%) and had a higher cancellation rate (18.5% versus 0.4%) compared with those with E2 levels < 80 pg/mL. Even when patients with elevated FSH levels (FSH > or = 15 mIU/mL) (conversion factor to SI unit, 1.00) were excluded (leaving 279 cycles), those with an elevated day 3 E2 still had a lower PR per initiated cycle (14.8% versus 38.9%) and maintained a higher cancellation rate (18.5% versus 0.4%). When the day 3 E2 was > or = 100 pg/mL there was a 33.3% cancellation rate and no pregnancies were achieved. CONCLUSION: Patients who presented with an elevated day 3 E2 (> or = 80 pg/mL) in a cycle before IVF-ET had a higher cancellation rate and achieved a lower PR independent of FSH level. A day 3 E2 level, in addition to a day 3 FSH level, appears very helpful in prospectively counseling patients regarding cancellation risk and ultimate IVF-ET success.

Adult↗
PubMed1993

Late outcome of valve replacement with the Cross-Jones caged-lens prosthesis.

A 58 year old woman underwent re-replacement of a Cross-Jones caged-lens mitral prosthesis 23 years after the first operation. She represented one of the 38 patients who received 42 Cross-Jones prostheses two decades earlier. Continued adequate performance for more than two decades in five patients bears a surprising testimony to the longevity of this historic low profile prosthesis.

Adult↗
PubMed1992

Expression of the insulin-like growth factor (IGF)-I and -II and the IGF-I and -II receptor genes during postnatal development of the rat ovary.

Solution hybridization/RNase protection assays were used to study the developmental expression of the insulin-like growth factor-I (IGF-I), IGF-II, IGF-I receptor, and IGF-II/mannose-6-phosphate receptor genes in the rat ovary between postnatal days 1-80. Maximal IGF-I mRNA levels occurred during the 15- to 25-day postnatal period, and the level on day 20 represented a 9-fold increase over the baseline at earlier and later stages. IGF-II mRNA levels were maximal during the 1- to 5-day postnatal period and subsequently declined to undetectable levels after day 10. IGF-I receptor mRNA levels increased 10-fold to a maximum in the 20- to 25-day postnatal period. This pattern was similar to the developmental pattern of [125I]IGF-I binding in the ovary. Two apparent peaks of IGF-II/mannose-6-phosphate receptor mRNA levels were seen, on day 20 and between days 50-80. These specific and significant changes in the expression of the genes encoding the IGFs and their receptors suggest a role for the IGF system in postnatal ovarian development.

Aging↗
PubMed1991

Reproductive potential in survivors of childhood malignancy.

The aggressive use of multiple therapeutic modalities has led to a significant increase in the number of survivors of childhood malignancy. These forms of cancer therapy have important effects on multiple organ systems. This review article evaluates the long-term effect of therapy on the reproductive potential of both boys and girls. While alkylating agents have been shown to cause a 50% reduction in the fertility potential of boys, they have almost no adverse effect in girls. Other chemotherapeutic agents and combinations of chemotherapeutic agents have also been shown to cause a greater reduction in the reproductive potential of girls than boys. Radiation produces severe dose-related gonadal damage in both boys and girls. The effect of Hodgkin's disease, leukemia and their therapies are evaluated. Despite the known mutagenic potential of some forms of cancer therapy there has not been an increased frequency of congenital abnormalities in the offspring of survivors of childhood cancer. The use of oophoropexy and other forms of prophylactic therapy to limit toxicity are also considered.

Adult↗
PubMed1990

Rapid percutaneous tracheostomy.

We describe a new method of performing percutaneous tracheostomy rapidly and safely using a specialized instrument kit. The technique permits the safe insertion of a full-sized 7.0 (ID) or 7.5 mm (ID) cuffed cannula into the trachea within 1-2 min, through the membranous second intercartilagenous space. Animal studies have demonstrated a superior healing process compared to that seen after conventional tracheostomy techniques.

Animals↗
PubMed1989

Proton NMR study of the influence on iron oxidation/ligation/spin state on the heme orientational preference in myoglobin.

Proton nuclear magnetic resonance spectroscopy has been utilized to demonstrate that the degree of heme orientational disorder within a given myoglobin protein matrix can be a sensitive function of the oxidation/ligation/spin state of the heme iron. For sperm whale deuterohemin-reconstituted myoglobin, the equilibrium was found to strongly favor (5.7 to 7.8 kJ/mol) the X-ray characterized heme orientation in all six-coordinate states, but with a considerable reduction in preference (to 1.6 kJ/mol) in the five-coordinate deoxy state. In native yellow fin tuna myoglobin, changes in heme orientational preferences of approximately 3 kJ/mol occur even between two six-coordinate ferric states differing solely in spin states.

Animals↗
PubMed1989

Percutaneous tracheostomy--a new method.

A rapid method of definitive low tracheostomy utilizing an original instrument kit and percutaneous approach is described. Through a horizontal, shallow (1.5-cm) skin incision in the neck, a 12-ga needle is introduced into the tracheal lumen. A flexible metal guidewire is gently introduced through the needle, which is then removed. A specially designed percutaneous tracheostomy tool slides over the guidewire into the trachea; by squeezing its handles, the intercartilaginous space is enlarged, securing the placement of a cuffed tracheal cannula. After extensive and successful investigation in both cadaver and animal trials, the procedure was carried out in 80 patients who had a variety of underlying diseases, without serious complications. Of these 80 patients, 33 required airway control after neurosurgical interventions or after severe head trauma, 23 had percutaneous tracheostomy performed before radical excision for head and neck cancer, and the remaining 24 suffered from severe cardiorespiratory problems. Twenty-nine procedures were performed in the operating theater, and 51 procedures were carried out at the patient's bedside in the ICU, ED, or in the ward. There was no infection at the stoma site, and late healing was remarkable. It should be strongly emphasized that in the majority of our patients the procedure was carried out safely at the bedside. This resolved the logistic problem of moving very sick ICU patients (who are sometimes on high PEEP levels) to the OR. Although our experience is totally restricted to elective situations, we do postulate that it could be as effective in a variety of urgent situations.

Adult↗
PubMed1988

Oligonucleotide N-alkylphosphoramidates: synthesis and binding to polynucleotides.

A few different methods for the preparation of oligonucleotide N-alkylphosphoramidates were compared directly. One of these, involving the use of protected nucleoside phosphites as building blocks, provided the requisite N-alkylphosphoramidates via oxidation of the intermediate dinucleoside methyl phosphites with iodine in the presence of the appropriate alkylamine. This method was found to have several attractive features, including the use of building blocks identical with those employed for the synthesis of DNA and compatibility with procedures and instruments employed for the stepwise synthesis of oligonucleotides by solution and solid-phase methods. This procedure was used to make several di-, tri-, and tetranucleotide N-alkylphosphoramidates derived from deoxyadenosine and thymidine; alkyl substituents included N,N-dimethyl, N-butyl, N-octyl, N-dodecyl, and N-(5-aminopentyl). The aminoalkyl derivative of d(TpT) (24) was used to demonstrate the feasibility of introducing an intercalative agent to the alkylphosphoramidate moiety of such derivatives. The oligonucleotide N-alkylphosphoramidates were separated into their component diastereomers and characterized structurally by a number of techniques including circular dichroism, high-field 1H NMR spectroscopy, FAB mass spectrometry, and enzymatic digestion to authentic nucleosides and nucleotides. Physicochemical characterization of several di- and trinucleotide alkyl-phosphoramidates revealed that the adenine nucleotide analogues formed stable complexes with poly-(thymidylic acid). The stabilities of these complexes were found to increase with increasing chain length of the N-alkylphosphoramidate substituents. The finding that N-alkylphosphoramidate substituents can enhance the binding of certain oligonucleotides to their complementary polynucleotides suggests the existence of a novel source of polynucleotide affinity.

Chemical Phenomena↗
PubMed1988

Copper(II) facilitates bleomycin-mediated unwinding of plasmid DNA.

The unwinding of plasmid DNA by bleomycin A2 (BLM A2) was investigated by use of two-dimensional gel electrophoresis. It was found that Cu2+ ions greatly facilitated the unwinding of topoisomers of plasmid DNA by BLM A2 at concentrations where cupric ions alone had no effect on DNA supercoiling. The concentration of BLM A2 required for observable unwinding was reduced at least 100-fold in the presence of equimolar Cu2+. A plot of [Cu2+] vs extent of DNA unwinding in the presence of 10(-4) M BLM A2 gave a curve consistent with the action of cupric ions on BLM in an allosteric fashion, possibly rearranging the drug into a conformation that facilitates DNA unwinding. The participation of the metal center in enhancing DNA unwinding via direct ionic interaction with one or more negatively charged groups on the DNA duplex also seems possible. Further analysis of the structural factors required for BLM-mediated DNA unwinding was carried out with Cu2+ + BLM demethyl A2, the latter of which differs from BLM A2 only in that it lacks a methyl group, and associated positive charge, at the C-terminus. Cu(II).BLM demethyl A2 was found to be much less effective than Cu(II).BLM A2 as a DNA unwinding agent, emphasizing the strong dependence of this process on the presence of positively charged groups within the BLM molecule. These findings constitute the first direct evidence that the metal center of BLM can participate in DNA interaction, as well as in the previously recognized role of oxygen binding and activation.

Bacteriophage phi X 174↗