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Biomedical subjects

M Quinn

Publications and source records attributed to M Quinn.

At least 163 records · Page 9Linked to original sources
PubMed1986

The effect of muscle movement on the electroencephalogram during anesthesia with alfentanil.

Using aperiodic analysis, we examined the impact on the electroencephalogram (EEG) of muscle activity from opiate-induced rigidity with alfentanil. We compared two groups of patients, one receiving alfentanil with neuromuscular blocking agents and the other group receiving no relaxants. The alfentanil-induced muscle rigidity exerted a noticeable effect on the EEG, with a moderate effect on total power at 1 Hz; a marked effect on the total number of waves, cumulative percent power at 3 Hz, and average power at 17 to 19 Hz; and a striking effect on F90, the frequency below which 90% of the power resides. The presence of electromyographic (EMG) noise in the EEG consistently altered the variables derived from the EEG, so that anesthetic depth appeared less than it actually was. This was true in spite of the fact that we gave slightly more alfentanil in the group not receiving a relaxant. Although the observed muscle activity was greater than that usually seen clinically, and may have differed qualitatively, the results do serve as a warning that muscle noise can interfere with the EEG. Currently, there is no computerized technique that will reject or account for this noise, and we must depend on observation to recognize the EMG patterns within the EEG, either with the raw recording or with a detailed analysis (such as aperiodic analysis), and to compensate for this noise if possible. Techniques that average the EEG or that present a single number have difficulty providing this information. These results do not detract from the usefulness of the EMG contained in EEG recordings as a supplementary or complementary indicator of anesthetic lightness.

Alfentanil↗
PubMed1986

Human alpha-galactosidase A: nucleotide sequence of a cDNA clone encoding the mature enzyme.

The complete nucleotide sequence has been determined for a lambda gt11 cDNA clone (lambda AG18) containing the full-length coding region for the mature lysosomal form of human alpha-galactosidase A (alpha-Gal A; EC 3.2.1.22). The lambda AG18 insert contained a 1226-base-pair sequence with an open reading frame encoding 398 amino acids of the mature polypeptide (predicted Mr = 45,356) and the last 5 amino acids of the propeptide sequence. The poly(A) signals AATACA and ATTAAA occurred 28 and 11 nucleotides prior to the TAA stop codon, respectively. There was no 3' untranslated region as the poly(A) sequence immediately followed the TAA termination codon; a second independently cloned cDNA confirmed this finding. The predicted amino acid sequence was colinear with 86 nonoverlapping residues (22% of the mature subunit) determined by microsequencing amino-terminal, tryptic, and cyanogen bromide peptides of the purified mature enzyme. Four potential N-glycosylation sites were identified, all of which occurred at predicted beta turns in hydrophilic regions of secondary structure. RNA transfer hybridization analysis of HeLa poly(A)+ RNA demonstrated a single 1.45-kilobase band whose signal was decreased by prior immunoabsorption of polysomes with monospecific alpha-Gal A antibodies. Searches of nucleic acid and protein data bases did not reveal significant homology even with the limited sequences available for mammalian lysosomal enzymes.

Amino Acid Sequence↗
PubMed1986

The use of 125I labelled staphylococcal protein A in the diagnosis of autoimmune thrombocytopenic purpura and other immune mediated thrombocytopenias.

Platelet-associated immunoglobulin (IgG) has been measured directly on platelets from normal and thrombocytopenic subjects by a modified radioactive Coombs technique. Platelet-associated IgG was detected using 125I-staphylococcal protein A after which platelets were separated from unbound 125I-protein A by centrifugation through oil. Elevated values of platelet-associated IgG were observed in 17 of 19 patients with autoimmune thrombocytopenic purpura. All patients with thrombocytopenia associated with systemic lupus erythematosus or rheumatoid arthritis showed elevated platelet-associated IgG, while normal values were found in diverse thrombocytopenias which were non-immunological in origin. Measurement of anti-platelet antibody levels by an indirect test was less reliable in diagnosing autoimmune thrombocytopenic purpura, since only 7 of the 19 patients gave elevated values. However, the indirect test was reliable in the diagnosis of quinine-dependent immune thrombocytopenia; all 6 patients with suspected quinine purpura gave strongly positive indirect tests when 1 mM quinine was added to the patient's plasma. The use of 125I-protein A to detect platelet-associated IgG provides a rapid and simple technique for the reliable diagnosis of immune thrombocytopenia.

Autoimmune Diseases↗
PubMed1985

An electroencephalographic comparison of alfentanil with other narcotics and with thiopental.

Using aperiodic analysis, we compared the EEG produced by alfentanil with the EEGs produced by two other opiates--fentanyl and sufentanil--on the one hand and with the EEG produced by a barbiturate--thiopental--on the other hand. Alfentanil and thiopental were injected over 1 minute; fentanyl and sufentanil were injected over 10 to 15 minutes. From the aperiodic analysis we derived up to seven single-number variables computed over 30- or 60-second epochs. All the opiates induced EEGs that were qualitatively similar to each other, although the maximum or minimum values tended to be greater and the time course more rapid with alfentanil than with the other two opiates. This finding may have been related to the fact that we injected relatively more alfentanil and administered it more rapidly. The EEGs produced by alfentanil and thiopental differed markedly, both qualitatively and quantitatively. The total power at 1 Hz and cumulative power at 3 Hz went to higher peak values with alfentanil, the latter tending to decrease with thiopental. The total number of waves per epoch went to lower peak values with alfentanil; there was little change with thiopental. The frequency below which 90% of the power resides went to considerably lower peak values with alfentanil than with thiopental. Finally, total power at 10 to 12 Hz (alpha waves) and average power at 17 to 19 Hz (beta waves) went to very high peak values with thiopental, but decreased with alfentanil.(ABSTRACT TRUNCATED AT 250 WORDS)

Alfentanil↗
PubMed1985

Fabry disease: isolation of a cDNA clone encoding human alpha-galactosidase A.

Fabry disease is an X-linked inborn error of metabolism resulting from the deficient activity of the lysosomal hydrolase, alpha-galactosidase A (alpha-Gal A; alpha-D-galactoside galactohydrolase, EC 3.2.1.22). To investigate the structure, organization, and expression of alpha-Gal A, as well as the nature of mutations in Fabry disease, a clone encoding human alpha-Gal A was isolated from a lambda gt11 human liver cDNA expression library. To facilitate screening, an improved affinity purification procedure was used to obtain sufficient homogeneous enzyme for production of monospecific antibodies and for amino-terminal and peptide microsequencing. On the basis of an amino-terminal sequence of 24 residues, two sets of oligonucleotide mixtures were synthesized corresponding to adjacent, but not overlapping, amino acid sequences. In addition, an oligonucleotide mixture was synthesized based on a sequence derived from an alpha-Gal A internal tryptic peptide isolated by reversed-phase HPLC. Four positive clones were initially identified by antibody screening of 1.4 X 10(7) plaques. Of these, only one clone (designated lambda AG18) demonstrated both antibody binding specificity by competition studies using homogeneous enzyme and specific hybridization to synthetic oligonucleotide mixtures corresponding to amino-terminal and internal amino acid sequences. Nucleotide sequencing of the 5' end of the 1250-base-pair EcoRI insert of clone lambda AG18 revealed an exact correspondence between the predicted and known amino-terminal amino acid sequence. The insert of clone lambda AG18 appears to contain the full-length coding region of the processed, enzymatically active alpha-Gal A, as well as sequences coding for five amino acids of the amino-terminal propeptide, which is posttranslationally cleaved during enzyme maturation.

Amino Acid Sequence↗
PubMed1985

Ultrasound-guided fetal blood transfusion for severe rhesus isoimmunization.

Four fetuses with severe rhesus isoimmunization were transfused with packed red blood cells directly into the umbilical vein. The outcome was successful in three. In one infant, this ultrasound-guided technique resulted in resolution of severe fetal hydrops at 27 weeks, allowing delivery of a healthy nonhydropic infant at 33 weeks, and in the other three infants in prolongation of the pregnancy. The last four transfusions were performed after fetal neuromuscular blockade with curare. The procedure would appear to be associated with a low risk of complication and to provide an excellent chance of a successful outcome of a fetus with severe rhesus isoimmunization even when fetal hydrops is present.

Blood Transfusion, Intrauterine↗
PubMed1984

Phosphorylation of ribosomal protein S6 and a peptide analogue of S6 by a protease-activated kinase isolated from rat liver.

A trypsin-activated protein kinase has been isolated from rat liver using a peptide analogue of ribosomal protein S6 as a substrate in kinase assays. The structure of the peptide, Arg-Arg-Leu-Ser-Ser-Leu-Arg-Ala, was based on a region of S6 containing both an insulin- and cyclic AMP-regulated phosphorylation site. The trypsin-activated protein kinase phosphorylated a corresponding site in the peptide analogue and ribosomal protein S6 that was distinct from the preferred site for cyclic AMP-dependent protein kinase. Ribosomal S6 contained at least one other major site for the trypsin-activated protein kinase.

Amino Acid Sequence↗
PubMed1982

Foodborne Norwalk virus.

On December 6, 1979, three luncheon banquets were served in a New Jersey restaurant. Thirty-eight of 41 members (92.7%) of the first group became ill as did 25 of 31 members (80.6%) of the second group. None of 12 members of the third group were ill. Illness consisted primarily of diarrhea (76%), nausea, (73%), vomiting (67%), cramps (46%) and fever (18%); the median incubation period was 31 hours and median duration 24 hours. The same foods were served to all three groups, except that cole slaw was substituted for a green salad and mixed vegetables for lima beans for the third group. Consumption of green salad was associated with illness (p less than 0.0001). A total of 118 other persons who ate at the restaurant on the same day were interviewed, 60% of whom reported being ill. Green salad was significantly associated with illness for this group at lunch (p = 0.005) and dinner (p = 0.00007). Serologic studies on seven of 12 patients and on one of four exposed controls showed a fourfold or greater rise in antibody titer to Norwalk virus.

Epidemiologic Methods↗
PubMed1981

Gray scale ultrasonography of a traumatic biliary cyst.

Traumatic hepatic biliary cysts, which occur when there is leakage after traumatic disruption of the biliary system, can be readily detected with hepatic sonography. Differentiation from other hepatic fluid collections can be made by percutaneous thin needle aspiration. Aspiration may have possible utility as a therapeutic modality. A case is presented in which Gray scale ultrasonography revealed a biliary cyst which was drained operatively and resolved.

Adult↗
PubMed1980

Intravenous cholangiography and sonography in acute cholecystitis: prospective evaluation.

Twenty-seven patients with clinically suspected acute cholecystitis were prospectively evaluated for supporting evidence with intravenous cholangiography and gray scale sonography. Twenty of these fulfilled criteria for inclusion in the study. Sonography was found to be helpful in all 20 patients (100%). Intravenous cholangiography could be performed in 16 patients (four patients had elevated bilirubin greater than 4 mg/dl). Of these 16, cholangiography was diagnostic in nine (56.3% accuracy). Because of the superiority of sonography and the morbidity and mortality associated with intravenous cholangiography, the study was terminated. Consequently, it is believed sonography is superior to intravenous cholangiography in the evaluation of suspected acute cholecystitis.

Acute Disease↗