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Biomedical subjects

M Gross

Publications and source records attributed to M Gross.

At least 451 records · Page 25Linked to original sources
PubMed1987

Usefulness of echocardiographically determined mitral leaflet motion for diagnosis of mitral valve prolapse in 17- and 18-year-old men.

Mitral leaflet motion during systole was studied by echocardiography in 102 healthy young men. Mean posterior maximal leaflet motion was 2 +/- 1 mm behind the CD line on 2-dimensionally (2-D) directed M-mode examination. On the apical 4-chamber cross-sectional view a mean area of 0.34 +/- 0.24 mm2 was contained by the mitral leaflets above the plane of the mitral anulus. Elevated values on the M-mode view (greater than or equal to 4 mm) compared with the 2-D 4-chamber view (greater than or equal to 0.70 mm2) were discordant, with 90% (18 of 20) of the elevated values found in 1 view only. Thus, there is a wide spectrum of mitral leaflet motion in asymptomatic young men. The value of the echocardiogram in diagnosis of mitral valve prolapse is questionable because any cutoff point between normal and abnormal is arbitrary and the degree of motion has not been shown to correlate with morbidity or mortality.

Adolescent↗
PubMed1987

Corneal wound healing after excimer laser keratotomy in a human eye.

A pulsed excimer argon-fluorine laser was used to produce corneal incisions in vivo in a human cornea. Fourteen days after the laser surgery, the incisions were examined by light and transmission electron microscopy. There was good initial healing, with no inflammatory or immune reactions in the incisions.

Adult↗
PubMed1987

Effect of antibody to the hemin-controlled translational repressor in rabbit reticulocyte lysate.

We have examined the effect of the purified IgG from the serum of guinea pigs immunized with a highly purified preparation of rabbit reticulocyte, hemin-controlled translational repressor (HCR) on protein synthesis in the reticulocyte lysate. We have found that the anti-HCR (but not non-immune) IgG completely prevents or reverses the suppression of protein synthesis that occurs in hemin-deficient lysate, providing a direct and definitive demonstration that the inhibitory effect of hemin-deficiency is mediated solely by the activation of HCR. The anti-HCR IgG also prevents or reverses the phosphorylation of eIF-2 alpha and the reduced binding of Met-tRNAf to 40 S ribosomal subunits that accompanies the inhibition of protein synthesis in hemin-deficient lysate. In contrast, the anti-HCR IgG has no effect on the inhibition produced by low levels of double-stranded RNA (that is due to the activation of a separate protein kinase), but it does partly reverse inhibition due to oxidized glutathione, ethanol, and phosphatidylserine, indicating that the effect of these components is mediated, at least in part, by the activation of HCR. Finally, we have confirmed our earlier observation that an excess of proHCR, the inactive precursor of HCR, has little effect on the neutralization of HCR by limiting anti-HCR IgG, suggesting that the antigenic determinants on HCR are not exposed on ProHCR.

Animals↗
PubMed1987

CpA containing oligoribonucleotides specifically inhibit protein synthesis in rabbit reticulocytes.

The diribonucleoside monophosphate CpA (and no others) inhibits polypeptide chain elongation in rabbit reticulocyte lysates at 10-50 microM. Furthermore, all the trinucleotides containing CpA, i.e., XpCpA and CpApX (X = U, C, A or G) block polypeptide chain elongation as well. At 10 microM the inhibition by XpCpA and not CpApX is transient because a 3'-exonucleolytic activity destroys the critical CpA moiety. The inhibitors do not appear to interfere with the aminoacylation of tRNAs or disrupt the interaction of amino-acyl-tRNAs with the protein synthetic machinery. High levels (200 microM) of CpA or the trinucleotides containing CpA have no effect on translation in a wheat germ cell-free system.

Adenosine↗
PubMed1987

Expression at the cell surface of native fusion protein of the Newcastle disease virus (NDV) strain Italien from cloned cDNA.

A cDNA library was constructed with poly(A)+-mRNAs from NDV-Italien infected BHK-21 cells. A clone, that hybridized to the F gene mRNA, was sequenced. A long open reading frame encodes for a protein of 553 amino acids, with a calculated molecular weight of 59,153, consisting of twelve cysteine residues and six potential glycosylation sites. The protein sequence contains a hydrophobic region at the N-terminus of F1 and a presumptive long transmembrane fragment near the C-terminus. Comparison of the F proteins from NDV strains Italien and Australia-Victoria shows that the sequences are very similar, with conservation of most cysteine residues and of the potential glycosylation sites. The F coding sequence was inserted into the genome of vaccinia virus under the control of vaccinia P7.5 transcriptional regulatory sequences. Expression of F protein was demonstrated by indirect immunofluorescence with five anti-F monoclonal antibodies known to react with conformational epitopes.

Amino Acid Sequence↗
PubMed1987

Isolation, characterization, and in vitro cultivation of keratinocyte subfractions from adult NMRI mouse epidermis: epidermal target cells for phorbol esters.

Adult dorsal mouse epidermis (strain NMRI) was separated from dermis in thin-split sections by cold trypsinization. From the isolated keratinocytes four cell fractions (F1-F4) were obtained using discontinuous Percoll density gradient centrifugation. The fractions were characterized by light microscopy, by indirect immunofluorescence using specific lectins (Bandeirea simplicifolia and Ulex europaeus) and an antibody against the spinous 67-kDa keratin polypeptides, and by electrophoretic analysis of the keratin polypeptide patterns. The heavy fractions, F3 and F4, were identified as being derived from the basal cell layer, whereas the light fractions, F1 and F2, consisted mainly of suprabasal cells. The basal cells (F3 and F4) could be cultivated on plastic substratum coated with rat-tail collagen (4 X MEM, 10% FCS at 34 degrees C; plating efficiency 70-85%). Labeling of DNA with [3H]thymidine indicated that during the first 5 days of cultivation, basal cells ran through two cell cycles, after which the proliferative activity ceased due to terminal differentiation. The addition of the tumor promoter TPA led to a stimulation of DNA synthesis in confluent cultures of both F3 and F4 cells.

Animals↗
PubMed1987

Serum cholesterol levels three years before and after viral hepatitis.

The serum cholesterol levels 3 years before and 3 years after an acute episode of hepatitis in 12 men aged 21-36 were compared to those in 22 age-matched controls. Serum cholesterol increased significantly during the acute icteric phase of the illness and remained elevated for 3 years after recovery. We conclude that cholesterol metabolism does not return to the prehepatitic state even 3 years after recovery.

Adult↗
PubMed1987

Identification of a human osteosarcoma-associated glycoprotein with monoclonal antibodies: relationship with alkaline phosphatase.

The molecular nature of an osteosarcoma-associated antigen was investigated with the three monoclonal antibodies Ost6 (immunoglobulin (IgG1), Ost7 (IgG1), and Ost15 (IgG2a), which selectively react with frozen sections of osteosarcoma and chondrosarcoma tissues. When tested with a panel of 41 human cell lines in the mixed hemadsorption assay, the antibodies reacted similarly with three of six osteosarcomas, one choriocarcinoma, one teratoma, and one osteoblast-like culture, but failed to react with 32 lines of normal and other tumor cell types. Immunoprecipitation plus sodium dodecyl sulfate (SDS)--polyacrylamide gel electrophoresis and sequential immunoprecipitation studies revealed that in [35S]methionine- or [14C]glucosamine-labelled osteosarcoma cells the three antibodies detected a single glycoprotein, with an apparent molecular mass of 86 kilodaltons (kDa), which was not affected by reducing conditions. Tunicamycin treatment and pulse-chase experiments showed glycosylation of this molecule to be N-linked; it arose from a 54-kDa polypeptide precursor. Alkaline phosphatase activity was detected in the material rich in 86-kDa molecules that was immunoprecipitated from serologically reactive cell lines with each antibody. These antibodies also cross-reacted with two isoenzymes of alkaline phosphatase (strongly with the liver and bone, and moderately with the placental isoenzyme), but not with the intestinal form.

Alkaline Phosphatase↗
PubMed1987

Influence of vasoactive intestinal peptide, secretin, and Ala4, Val5-secretin on the net movements of electrolytes, fluid, and mucus in the rat colon in vivo.

The effect of vasoactive intestinal peptide (VIP), secretin, and VIP-secretin (Ala4, Val5-secretin) on the net movements of sodium, potassium, fluid, and mucus was investigated in the rat colon perfused in vivo. Peptides (1-100 micrograms/kg.h) were infused intra-arterially. VIP influenced electrolyte and fluid movements at a threshold dose 10- to 100-fold lower than secretin, whereas the secretory efficacy was not significantly different. Replacing the NH2-terminal hexapeptide of secretin by that of VIP did not markedly alter the effect of secretin. Mucus output was stimulated weakly by all three peptides. The results indicate that the larger colonic secretory activity of VIP as compared to secretin is not primarily due to the difference in their NH2-terminal sequence but probably requires the intact molecule.

Animals↗
PubMed1987

Predictive value of premature ventricular contractions on the resting electrocardiogram for ventricular arrhythmias on 24 hour monitoring in asymptomatic young adults.

Between the years 1981-1984, 89 air-personnel, ages 18-45 years, underwent 24-hour ambulatory ECG monitoring at the Israel Air Force Aeromedical Center due to an incidental finding of one or more premature ventricular contractions (PVCs) on the resting supine 12-lead ECG. Complex ectopic arrhythmias (bigemini, trigemini, couplets, ventricular tachycardia, R on T phenomenon, or multifocal patterns) were observed during monitoring in 1.4% of 138 control subjects without PVCs, in 22% of those with 1 to 3 PVC X min-1 and in 68% of those with 4 or more PVC X min-1 on the resting ECG. Altogether 39(44%) of the 89 subjects with PVCs on the resting ECG had complex ectopic rhythms on monitoring. Of the 43 subjects with available follow-up data, 3 (7%) reported bouts of dizziness and light headedness which coincided with complex ectopic rhythms. In one of these three subjects, the bouts of dizziness coincided with runs of ventricular tachycardia during exercise testing.

Adult↗
PubMed1987

Low back pain in the AH-1 Cobra helicopter.

Pilots of the AH-1S helicopter maintain a vertical sitting position in the gunner's position (front seat), whereas in the pilot's seat (rear), they lean forward and to the left in order to operate the controls. A cross over study with pilots flying alternately in the front and rear positions was used to assess the effect of crew position on the prevalence of low back pain during flight. In the pilot's seat, there was an increased prevalence of pain (72.2%, 13/18 versus 55.6%, 10/18); the onset of pain was quicker than experienced in the gunner's position (64.3%, 9/14 versus 7.1%, 1/14, p less than 0.001); and the intensity was greater (85.7%, 12/14 versus 7.1%, 1/14, p less than 0.001). We conclude that posture is an important component of the low back pain experienced by helicopter pilots during flight.

Adult↗