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Biomedical subjects

M Mann

Publications and source records attributed to M Mann.

At least 217 records · Page 12Linked to original sources
PubMed1989

Electrospray ionization for mass spectrometry of large biomolecules.

Electrospray ionization has recently emerged as a powerful technique for producing intact ions in vacuo from large and complex species in solution. To an extent greater than has previously been possible with the more familiar "soft" ionization methods, this technique makes the power and elegance of mass spectrometric analysis applicable to the large and fragile polar molecules that play such vital roles in biological systems. The distinguishing features of electrospray spectra for large molecules are coherent sequences of peaks whose component ions are multiply charged, the ions of each peak differing by one charge from those of adjacent neighbors in the sequence. Spectra have been obtained for biopolymers including oligonucleotides and proteins, the latter having molecular weights up to 130,000, with as yet no evidence of an upper limit.

Ions↗
PubMed1988

Isolation and primary structure of human peptide YY.

The isolation, primary structure and chemical synthesis of human peptide YY (PYY) are described. The peptide was purified from human colonic extracts using a chemical method which detected the C-terminal tyrosine amide structure of PYY. Human PYY consists of 36 amino acid residues and the complete amino acid sequence is: Tyr-Pro-Ile-Lys-Pro-Glu-Ala-Pro-Gly-Glu- Asp-Ala-Ser-Pro-Glu-Glu-Leu-Asn-Arg-Tyr-Tyr-Ala-Ser-Leu-Arg-His-Tyr-Leu- Asn-Leu-Val-Thr-Arg-Gln-Arg-Tyr-NH2. The differences between the structures of porcine and human PYY are at positions 3 (Ala/Ile replacement) and 18 (Ser/Asn). Synthetic human PYY prepared using a solid-phase synthetic technique was found to be structurally identical to the natural peptide.

Amino Acid Sequence↗
PubMed1987

On the diversity of sperm basic proteins in the vertebrates: V. Cytochemical and amino acid analysis in Squamata, Testudines, and Crocodylia.

The variability of sperm basic proteins in representatives of three reptilian orders, Squamata, Testudines, and Crocodylia, has been examined by cytochemistry, acid-urea polyacrylamide gel electrophoresis, and amino acid analysis of amidoblack-stained bands. Snakes contain type 3B intermediate sperm basic proteins by cytochemical criteria. Electrophoresis of basic proteins from epididymis chromatin as well as from testis and ductus deferens cell suspensions shows two fast-moving bands in the vicinity of herring protamine. These proteins are triprotamines containing about 27 mol % arginine, along with lysine and histidine. Lizards have type 1 protamines in their sperm nuclei cytochemically and also show a two-banded electrophoretic pattern similar to that of snakes. However, these proteins are triprotamines, similar to those in snakes with 25 mol % arginine. It may be that these are testis-specific proteins of the spermatid stage in lizards since a cytochemical transition can be observed from type 3A intermediate proteins in spermatids of testis to type 1 protamine in mature sperm of ductus deferens. Turtles contain type 3A intermediate sperm basic proteins cytochemically and basic proteins from epididymis chromatin display both a prominent band and a minor band close to, but slightly slower than, the two bands for snakes and lizards. Amino acid analysis of these bands shows that these basic proteins are also triprotamines but with a higher level of arginine, about 48 mol %, than that in snake and lizard sperm proteins. Basic proteins from epididymis chromatin of a single Mississippi alligator show three main bands moving close to the bands of snakes, lizards, and turtles. These proteins have amino acid compositions typical for triprotamines, with 28-39 mol % arginine. The data indicate that the sperm basic proteins of representatives of 25 species in three reptilian orders are very similar, in contrast to the diversity of sperm protein types found in frogs (Kasinsky, Huang, Kwauk, Mann, Sweeney, and Yee: J. Exp. Zool., 203:109-126, '78; Kasinsky, Huang, Mann, Roca, and Subirana: J. Exp. Zool., 234:33-46, '85a). This appears to be part of a macroevolutionary trend from diversity of sperm basic proteins in frogs to relative constancy in reptiles (Kasinsky, Mann, Pickerill, Gutovich, and Byrd, Jr.:J. Cell Biol., 91:1879, '81; Kasinsky, Mann, Lemke, and Huang: In: Chromosomal Proteins and Gene Expression, Plenum Press, New York, pp. 333-352, '85b). We present the hypothesis that one factor for such a trend resides in the fact that fertilization is internal in reptiles but external in anurans.

Amino Acids↗
PubMed1986

Detection of sperm histone diversity among vertebrates by alkaline fast green staining.

Testis sections from fifteen species from six classes of vertebrates were stained with alkaline fast green (AFG) to correlate staining differences with the known biochemical diversity of histones in the spermatozoa. After trichloroacetic acid (TCA) hydrolysis the sperm of some species known to contain sperm-specific histones did not stain. This correlation held if fixation in neutral buffered formalin was limited to 3 to 6 hr and hydrolysis was done at 90 C. The species whose sperm did stain after TCA hydrolysis could be divided into three groups. In some species the sperm no longer stained if, after TCA, the sections were treated with thioglycollic acid. These sperm contained basic proteins that were rich in cysteine. In turn, the group of species whose sperm continued to stain after TCA and thioglycollic acid treatments could be subdivided. The sperm of some were stained specifically without DNA hydrolysis if the AFG was made up with sodium chloride. These sperm contained sperm-specific histones. In other species the sperm did not stain under these conditions, and these sperm had a basic protein complement similar to that found in somatic cell nuclei. These correlations suggest that AFG staining can be used to detect sperm histone diversity in a wide range of organisms.

Animals↗
PubMed1985

On the diversity of sperm histones in the vertebrates: IV. Cytochemical and amino acid analysis in Anura.

The variability of sperm histones in frogs has been studied by cytochemical and amino acid analyses. Cytochemically, Rana sperm proteins fall into Bloch's ('69, '76) type 4 somatic-like histone category, while Xenopus and Bufo have type 3 intermediate sperm histones. Extractability in 5% trichloroacetic acid (TCA) at different temperatures splits this type 3 category into two groups: type 3B intermediate sperm histones of Bufo are extractable at 85-90 degrees C, while Xenopus intermediate type 3A sperm histones require temperatures of 95-100 degrees C for extraction. Amino acid analysis confirms that Rana sperm histones are of the nucleosomal type, with a testis-specific, very lysine-rich H1 histone. The sperm protein in Bufo is richer in arginine than the proteins in Xenopus. Both of these genera contain lysine and histidine as well as arginine in their sperm proteins. These results confirm earlier electrophoretic data (Kasinsky et al., '78) and indicate that sperm histones in the order Anura can vary markedly between different genera.

Amino Acids↗
PubMed1985

Cryptic vascular malformations diagnosed by stereotactic biopsies--a preliminary study.

A series of 14 cryptic vascular malformations (CVM) deeply situated or localized in functional cortical areas were diagnosed by serial stereotactic biopsies. No history was suggestive of hemorrhage, despite a substantial hematoma being evacuated during biopsy procedures in 4 patients. Retrospectively, CVM without hematoma were found to have certain characteristics that should raise the suspicion as to the correct diagnosis. At the time of discharge from the hospital, only 1 patient had mild aggravation of a preexisting motor deficit, which further improved. Serial stereotactic biopsies provided the required histological diagnosis with relatively low risk.

Adolescent↗
PubMed1985

[Objective and subjective needs of mental patients 1 year after their discharge from a sectorized service].

The present paper is based on a study of 50 non-randomized psychiatric patients who had left the hospital one year before. A semi-structured interview was used to acquire the data. Two types of data have been collected: objective and subjective. Objective data concern the diagnosis, marital status, living conditions, economic situation, educational and professional levels and medical care after hospitalization. As a whole living conditions were found to be very poor. Subjective data concern patients complaints, financial difficulties, their needs and their desire to get in contact with the community health center during hospitalisation. Most patients were in favour of starting after care just prior to discharge. All data are discussed. The most interesting finding is, that despite the many socio-economic hardships, the primary need expressed by the patients is a valuable personal relationship.

Adult↗
PubMed1984

Therapist agreement for palpation and observation of iliac crest heights.

Ten subjects were assessed by 11 examiners (three physical therapy students, three physical therapists experienced in rehabilitation, and five physical therapists experienced in orthopedics) to determine intrarater and interrater agreement for an assessment procedure involving palpation and observation of iliac crest heights. The results of two separate trials in a single session showed that both groups of experienced physical therapists had slightly higher intrarater and interrater agreement than student physical therapists. Findings suggest that a need exists to improve the reliability of this commonly used physical therapy assessment procedure.

Adipose Tissue↗
PubMed1984

Patterns of electrochemical proton gradient formation by membrane vesicles from an obligately acidophilic bacterium.

Isolated membrane vesicles from the obligately acidophilic bacterium Bacillus acidocaldarius generated an electrochemical gradient of protons (delta mu- H+) upon energization with ascorbate-phenazine methosulfate at pH 6.0 or 3.0. At pH 6.0, there was little or no transmembrane pH gradient (delta pH), but a transmembrane electrical potential (delta psi) of ca. -77 mV, positive out, was observed. At pH 3.0, a delta pH equivalent to - 100 mV, acid out, and a delta psi of -73 mV, positive out, were observed upon energization. The total magnitude of the delta mu- H+ was higher than that of whole cells at acid pH, but the very large delta pHs and the reversed delta psi s, i.e., inside positive, that are typical of acidophile cells were not observed in the vesicles. The vesicles exhibited energy-dependent accumulation of alpha-aminoisobutyric acid that was inhibited by both nigericin and valinomycin (plus K+) at pH 3.0 but was inhibited little by nigericin at pH 6.0.

Aminoisobutyric Acids↗
PubMed1984

SES-related aspects of neuropsychological performance.

Children from different socioeconomic backgrounds have been observed to employ different cognitive styles in problem-solving situations. These cognitive styles have in turn been linked to the functional specialization of the cerebral hemispheres. It was hypothesized, therefore, that performance asymmetries would also be SES-related, high-SES children processing stimuli presented to the right visual field-left hemisphere (RVF-LH) more efficiently than those presented to the left visual field-right hemisphere (LVF-RH) and low-SES children showing the reverse pattern. A laterality task was administered tachistoscopically to 120 children, divided evenly by SES (high and low), sex, and grade (fifth and seventh). A marked RVF-LH advantage emerged among the high-SES group and a weak LVF-RH advantage among the low-SES group. Thus, the results provided general support for the central hypothesis. The findings are reviewed in the context of current models of human information processing in the cerebral hemispheres, and their broader implications for understanding SES-related differences in cognitive function are discussed.

Child↗
PubMed1984

Plasma exchange (PE) and lymphocytapheresis (LCA) in multiple sclerosis (MS).

In 96 patients suffering from multiple sclerosis (MS) 277 plasma exchanges (PE) including 176 lymphocytaphereses were performed. Improvement was mainly seen in patients with a short course of disease and at acute exacerbations. Patients with chronic progressive and relapsing intermittent courses responded only poorly. One or two PE were sufficient to induce improvement which was only marginally altered by subsequent PE. Our data confirm that only selected patients will benefit from PE-treatment especially those with acute exacerbations.

Acute Disease↗