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Biomedical subjects

J Mazer

Publications and source records attributed to J Mazer.

14 recordsLinked to original sources

Mammographic localization and biopsy: the experience of a gynecologic oncology group.

From 1976 through 1986, two hundred eighty or 9% of all breast biopsies performed by a private gynecologic oncology group were for mammographically suspicious but occult breast lesions. Sixteen percent were found to be malignant. There has been improvement in mammographic techniques, and localization procedures have evolved to the current use of hooked-wire needles, which allow for the excision of smaller amounts of tissue and use of outpatient surgery facilities. Recently, the cancers encountered have been more often carcinoma in situ rather than invasive lesions. With the current increase in mammographic screening, there needs to be a continuing evolution in diagnostic modalities.

Adult

Ovarian follicular maturation in women. I. Intermittent versus daily administration of human menopausal gonadotropin.

This study was designed to compare the efficiency of daily intramuscular human menopausal gonadotropin (hMG) therapy to an intermittent subcutaneous regimen in women with ovulatory dysfunction. Ovarian follicular development was assessed with the use of serial ultrasound scans and serum 17 beta-estradiol (E2) levels. Ovulation was based on pregnancy and/or elevated luteal progesterone values. There were no significant differences between the two treatment regimens, based on E2 levels, follicular size, and/or number of follicles greater than 1.0 cm. Pregnancy and ovulation occurred more frequently after intramuscular hMG therapy. These results indicate that daily hMG is preferred over intermittent subcutaneous administration because of convenience.

Adult

Comparative stability and catalytic and chemical properties of the sulfate-activating enzymes from Penicillium chrysogenum (mesophile) and Penicillium duponti (thermophile).

ATP sulfurylases from Penicillium chrysogenum (a mesophile) and from Penicillium duponti (a thermophile) had a native molecular weight of about 440,000 and a subunit molecular weight of about 69,000. (The P. duponti subunit appeared to be a little smaller than the P. chrysogenum subunit.) The P. duponti enzyme was about 100 times more heat stable than the P. chrysogenum enzyme; k inact (the first-order rate constant for inactivation) at 65 degrees C = 3.3 X 10(-4) s-1 for P. duponti and 3.0 X 10(-2) s-1 for P. chrysogenum. The P. duponti enzyme was also more stable to low pH and urea at 30 degrees C. Rabbit serum antibodies to each enzyme showed heterologous cross-reaction. Amino acid analyses disclosed no major compositional differences between the two enzymes. The analogous Km and Ki values of the forward and reverse reactions were also essentially identical at 30 degrees C. At 30 degrees C, the physiologically important adenosine 5'-phosphosulfate (APS) synthesis activity of the P. duponti enzyme was 4 U mg of protein-1, which is about half that of the P. chrysogenum enzyme. The molybdolysis and ATP synthesis activities of the P. duponti enzyme at 30 degrees C were similar to those of the P. chrysogenum enzyme. At 50 degrees C, the APS synthesis activity of the P. duponti enzyme was 12 to 19 U mg of protein-1, which was higher than that of the P. chrysogenum enzyme at 30 degrees C (8 +/- 1 U mg of protein-1). Treatment of the P. chrysogenum enzyme with 5,5'-dithiobis(2-nitrobenzoate) (DTNB) at 30 degrees C under nondenaturing conditions modified one free sulfhydryl group per subunit. Vmax was not significantly altered, but the catalytic activity at low magnesium-ATP or SO4(2-) (or MoO4(2-)) was markedly reduced. Chemical modification with tetranitromethane had the same results on the kinetics. The native P. duponti enzyme was relatively unreactive toward DTNB or tetranitromethane at 30 degrees C and pH 8.0 or pH 9.0, but at 50 degrees C and pH 8.0, DTNB rapidly modified one SH group per subunit. APS kinase (the second sulfate-activating enzyme) of P. chrysogenum dissociated into inactive subunits at 42 degrees C. The P. duponti enzyme remained intact and active at 42 degrees C.

Amino Acids

Cystic meconium peritonitis: ultrasonographic features.

Meconium peritonitis occasionally occurs as a localized, encysted collection of meconium ranging from a few centimeters in size to huge cysts occupying most of the abdominal cavity. The cyst wall consists of fibrous granulation tissue and the cyst may contain only meconium or may also encase loops of bowel. Gas within the cyst indicates persistent communication between the perforated bowel and the cyst cavity; if the perforation seals over in utero the cyst remains gasless. Calcification is a variable finding. Sonography in two neonates with cystic meconium peritonitis showed well-defined, echogenic masses, one of which contained calcifications and was detected in utero.

Adolescent

Sonographically documented disappearance of fetal ascites.

Two patients with sonographically documented fetal ascites are described. Workup for immunologic or nonimmunologic causes was negative. Subsequent sonar examinations demonstrated disappearance of fetal ascites. At delivery, previous abdominal distention was apparent. Fetal ascites of unknown etiology in the late second trimester does not necessarily have a poor prognosis. Serial sonographic examinations are indicated for follow-up of fetal ascites.

Adult

Ultrasonography of partial hydatidiform mole.

Partial hydatidiform mole differs from complete mole by its focal distribution, its slower transformation, the presence of an embryo or fetus, and the triploid karyotype. Nineteen pathologically proved cases are presented. Partial mole can be diagnosed by a combination of the following sonographic findings: (a) greatly enlarged placenta relative to the size of the uterine cavity, (b) cystic spaces within the placenta ("molar placenta"), which may not always be present, (c) an amniotic cavity (gestational sac), either empty or containing amorphous fetal echoes, and (d) a well-formed but growth-retarded fetus, either dead or alive.

Abortion, Spontaneous

Short rib-polydactyly syndrome type 3.

Three infants died perinatally of asphyxia due to thoracic narrowing. Their uniform radiographic findings are different from previously described and recognized chondrodysplasias and possibly represent a distinct syndrome. Three identical or very similar cases are found in the literature.

Bone Diseases, Developmental