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Biomedical subjects

H Young

Publications and source records attributed to H Young.

At least 181 records · Page 10Linked to original sources
PubMed1985

Low sodium attenuation of the Ca2+ paradox in the newborn rabbit myocardium.

The effect of low sodium (Na 24 mM) perfusate during Ca2+ depletion on mechanical function, tissue high-energy phosphate, creatine kinase (CK) release, and tissue potassium was studied in the arterially perfused newborn and adult rabbit heart. During Ca2+ depletion, the time for DT and +dT/dtmax to decline to half-maximal value in newborn muscles perfused with low Na (46 +/- 3 S) was significantly (P less than 0.05) longer than the value obtained with normal Na (14 +/- 1 S). Similar values were obtained in the adult. During Ca2+ repletion, the increase in resting tension and CK release was attenuated in the low Na groups, and the values in the newborn were significantly less than in the adult. The recovery of +dT/dtmax and tissue high-energy phosphates in the low Na groups were significantly greater than in the normal Na groups, and the values in the newborn were significantly greater than in the adult. These data suggest that low Na during the Ca2+-free period delays both cellular Ca2+ depletion during the Ca2+-free period and Ca2+ influx during Ca2+ repletion. This effect in the newborn is greater than in the adult and might be explained by Na+-Ca2+ exchange.

Adenine Nucleotides↗
PubMed1985

Calcium paradox in the neonatal heart.

The age-dependent effect of a calcium-free medium on myocardial mechanical function, high energy phosphates (HEP), as well as HEP and creatine phosphokinase (CPK) release was studied in the arterially perfused rabbit heart. The effect in the newborn was significantly less than in the adult with the transition occurring between two and five weeks of age. Thirty minutes of Ca2+ depletion had no significant effect on tissue high energy phosphate, creatine phosphokinase (CPK) release and creatine release. During Ca2+ repletion, the recovery in developed tension (DT) and +dT/dt (max) in the newborn was significantly greater than in the adult. The increase in resting tension in the newborn was significantly less in the newborn than in the adult. A significant decrease in tissue adenosine triphosphate (ATP) and CP was observed after Ca repletion following 5 minute Ca depletion in the adult and only after 30 minutes depletion in the newborn. Significant increases in CPK, creatine, and adenine nucleotide release were observed during Ca2+ repletion and the amounts released in the adult were significantly greater than in the newborn. There was a significant correlation between the percent recovery of +dT/dt (max) and tissue ATP content in both age groups. In addition, there was an inverse correlation between the recovery of +dT/dt (max) and log CPK release. These data indicate that the Ca2+ paradox effect is minimal in the newborn rabbit and becomes similar to that of the adult at five weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗
PubMed1984

Immunological identification of Neisseria gonorrhoeae with monoclonal and polyclonal antibody coagglutination reagents.

The reliability of immunological identification of Neisseria gonorrhoeae using polyclonal and monoclonal antibody coagglutination reagents has been evaluated. When clinical isolates of neisseriae were tested in an "in use" trial the sensitivity and specificity of each reagent were similar and the overall agreement with carbohydrate utilisation was 97.9% (141/144) for the polyclonal antibody reagent and 97.2% (140/144) for the monoclonal reagent. When results of testing 13 stock cultures of N lactamica and five stock cultures of beta-lactamase producing Branhamella catarrhalis were combined with the results for clinical isolates of non-gonococcal neisseriae the agreement with carbohydrate utilisation was 86.5% (64/74) for the polyclonal reagent and 97.3% (72/74) for the monoclonal reagent: this difference is statistically significant at the 5% level. Calculation of positive and negative predictive values showed differences in the reliability of the coagglutination reagents when testing Gram negative diplococci isolated from various anatomical sites. The value and limitations of the polyclonal and monoclonal reagents were similar with respect to anogenital isolates: N gonorrhoeae was confirmed by a positive result but not excluded by a negative result. The monoclonal reagent was superior for testing throat isolates; although a negative result with either reagent confirmed Gram negative diplococci as non-gonococcal neisseriae, a positive result with the monoclonal reagent was more reliable (predictive value 93%) than a positive result with the polyclonal reagent (predictive value 86%).

Agglutination Tests↗
PubMed1984

Differentiation of gonococcal and non-gonococcal neisseriae by the superoxol test.

We evaluated the superoxol (catalase) test as a means of differentiating gonococci from related species of organisms which were cultured from a variety of anatomical sites. An isolate was almost certainly not a gonococcus if it gave a negative superoxol test result, as all but one of 596 available gonococci gave positive test results. However, a proportion of the non-gonococcal neisseriae and isolates of Branhamella catarrhalis, also gave positive test results. The superoxol test is thus a useful addition to the techniques available for the characterisation of gonococci, but additional procedures are needed to confirm the identities of isolates giving positive results.

Bacteriological Techniques↗
PubMed1984

Serogrouping Neisseria gonorrhoeae: correlation of coagglutination serogroup WII with homosexually acquired infection.

With coagglutination reagents prepared against W antigens, 205 clinical isolates of Neisseria gonorrhoeae were classified into three serogroups WI, WII, and WIII. Of 195 strains isolated from patients who acquired their infection in the Edinburgh area, 85 (44%) belonged to serogroup WI and 110 (56%) to serogroup WII. Serogroup WII accounted for 90% of all isolates from homosexual men and for 34% and 47% of isolates from heterosexual men and women respectively (p less than 0.001). In homosexual men serogroup WII predominated regardless of the anatomical site from which the strain was isolated, and accounted for 94% of rectal, 90% of urethral, and 81% of pharyngeal isolates.

Agglutination Tests↗
PubMed1983

Ano-genital gonorrhoea and pharyngeal colonisation with meningococci: a serogroup analysis.

Among patients attending a clinic for sexually transmitted diseases, women without gonorrhoea were significantly less likely to be colonised with meningococci than were women with gonorrhoea, men with gonorrhoea and men without gonorrhoea: the respective carriage rates (per cent) for groupable plus non-groupable meningococci were 16, 26, 23 and 31. Considering groupable and non-groupable meningococci separately it was found that women without gonorrhoea were also significantly less likely to be colonised with groupable meningococci but there were no significant differences in the carriage rates of non-groupable meningococci. The association between ano-genital gonorrhoea and meningococcal colonisation of the pharynx observed previously with certain groups of patients most likely results from increased mouth-to-mouth contact in 'high-risk' patients rather than individual susceptibility to neisserial infection. The possibility that there is a difference in the predominant means of spread of groupable and non-groupable meningococci is discussed.

Anus Diseases↗
PubMed1983

Non-cultural detection of Neisseria gonorrhoeae in cervical and vaginal washings.

Genetic transformation, an indirect sandwich enzyme-linked immunosorbent assay (ELISA) and the Limulus amoebocyte assay were used to indicate the presence of products of Neisseria gonorrhoeae in vaginal and uterine cervical aspirates from 37 women attending a Department of Genito-Urinary Medicine. In parallel with these tests, qualitative and quantitative assessments of the microbial content of aspirates were made. There was wide variation in the numbers of gonococci cultured. The mean viable count for cervical aspirates was 1 x 10(6) cfu/ml and the range was (5 x 10(3))-(8 x 10(6)) cfu/ml; the mean count for vaginal aspirates was 8.4 x 10(4) cfu/ml and the range (1 x 10(2))-(1 x 10(6)) cfu/ml. Viable counts of organisms other than gonococci in vaginal aspirates were two to tenfold greater than the corresponding counts for cervical aspirates. Of 20 patients with gonorrhoea confirmed by conventional diagnostic cultures, aspirates from 15 (75%) gave a positive transformation result, and 12 (60%) a positive ELISA result; 16 (84.2%) out of 19 of these aspirates tested by the Limulus lysate assay were positive at a dilution of 1 in 100.

Cervix Uteri↗
PubMed1983

Neisserial colonisation of the pharynx.

The spectrum of neisserial colonisation of the pharynx was determined from 3557 throat exudates cultured on modified New York City (MNYC) medium. Oxidase positive Gram-negative diplococci (GNDC) were isolated from 1204 (33.8%) of the throat cultures. Neisseria gonorrhoeae, N meningitidis, and N lactamica accounted for 20.3%, 74.2%, and 3.7% of the oxidase positive GNDC respectively. The observed coexistence of gonococci and meningococci in the pharynx (0.39%) was significantly different (p less than 0.001) from the theoretical expected value (1.7%). The prevalence of pharyngeal infection in patients with gonorrhoea was 4.3% for all men, 11% for homosexual men, and 7.9% for women. Despite the risks of disseminated infection and spread to sexual partners, the detection of pharyngeal gonorrhoea is less important than that of endocervical infection in women, urethral infection in heterosexual men, and anorectal infection in homosexual men.

Ampicillin↗
PubMed1983

Dietary patterns of third-year secondary schoolgirls in Glasgow.

The dietary pattern of 270 third-year secondary schoolgirls in Glasgow was investigated by means of a 24-hour recall. Subjects were asked to indicate any food which they had bought themselves and to answer questions relating to fat, sugar and fibre. Most ate at normal mealtimes including breakfast but additional snacking was prevalent especially in the evening. There was a distinct lack of fruit and vegetables in the diet. The subjects could exercise reasonable influence over their own intake by virtue of their purchasing power. The roles of fat, sugar and fibre in the diet were variably understood and sources of fibre not well recognised.

Adolescent↗
PubMed1982

Detection of gonococcal antigens by an indirect sandwich enzyme-linked immunosorbent assay.

The detection of gonococcal antigens by an indirect sandwich ELISA system is described. The feasibility of using rabbit antiserum raised against whole cells of Neisseria gonorrhoeae strain 9 to detect gonococcal lipopolysaccharide, whole cells, and outer membrane (OM) protein was investigated. OM protein was found to be the main antigen detectable with the antiserum in a direct ELISA system. A positive result in the indirect assay could be obtained with a minimum of 46 to 92 ng of gonococcal OM protein or with 6.6 X 10(3) cfu of N. gonorrhoeae. The sensitivity of the assay was found to be approximately eightfold lower with OM complex from a strain of N. meningitidis serogroup B for which the minimum amount of OM protein detected was 375 ng. Negative results were obtained with OM complex from Streptococcus agalactiae, Bacteroides bivius and Escherichia coli. The assay seems to be highly specific for gonococcal antigens. The sensitivity of the assay and its specificity commend it for further evaluation in the detection of gonococcal antigens in clinical specimens.

Antigens, Bacterial↗
PubMed1982

The use of paraffin-processed tissue and the immunoperoxidase technique in the diagnosis of bullous diseases, lupus erythematosus and vasculitis.

Twenty-two skin biopsies have been split and each half examined either by the immunoperoxidase technique on paraffin-fixed tissue or by both immunoperoxidase (IP) and immunofluorescence (IF) technique on snap-frozen tissue. All twenty-two specimens gave positive results by frozen IF techniques, nineteen out of twenty-two (86%) were positive by frozen IP techniques and sixteen out of twenty-two (72%) were positive by IP on paraffin-fixed material. If retrospective immunopathology is required on a specimen and only paraffin-fixed material is available a positive result may be expected in the majority of cases.

Dermatitis Herpetiformis↗
PubMed1982

On the importance of CSF Na in the regulation of renal sodium excretion and renin release.

Infusions (20 microliters/min) of isotonic (0.27 M) mannitol dissolved in Na-free artificial cerebrospinal fluid (CSF) were made for 2 h into the lateral cerebral ventricle (IVT) of conscious 68 h dehydrated sheep. The IVT infusion induced a conspicuous drop in renal sodium excretion and marked rise in plasma renin concentration (PRC). The antinatriuretic response to the IVT infusion was not altered by the intravenous administration of ADH or te converting enzyme blocker (SQ 14225, Captopril). Surgical bilateral renal denervation did not change the antinatriuretic response while the increase in PRC was extinguished. Samples of CSF were collected prior to, and 15 min after the end of the infusion. These showed a reduction in CSF [Na], while CSF osmolality remained unchanged. The study supports the view that sodium sensitive receptors close to the cerebral ventricular system participate in the regulation of renal sodium excretion and renin release, it also suggests that renal sodium excretion is affected by an unknown hormonal factor of cerebral origin, while the release of renin seen in response to a reduction in CSF [Na] is mediated by the renal nerves.

Animals↗
PubMed1982

Rapidity and reliability of gonococcal identification by coagglutination after culture on modified New York City medium.

The combination of culture on modified New York City (MNYC) medium and identification of neisserial isolates by the Phadebact gonococcus test was evaluated in routine laboratory practice. The sensitivity of coagglutination was 96.7% (318/329 isolates) and that of immunofluorescence (IF) 97.9% (322/329 isolates); the specificity of both methods was 96.8% (120/124 isolates). Of the 329 gonococcal isolates, 286 (86.9%) could be tested by coagglutination and 309 (93.9%) by IF after only 24 hours' incubation. Identification by coagglutination from primary cultures on MNYC medium is considered to be very rapid, simple, and efficient for the cultural diagnosis of anogenital gonorrhoea in women and urethral gonorrhoea in men. Because of the high prevalence of meningococci in the pharynx and their not infrequent occurrence in the anorectum of homosexual men the identity of isolates from these sites is best confirmed by sugar utilisation tests.

Adult↗
PubMed1981

Chlamydia trachomatis and Ureaplasma urealyticum in men attending a sexually transmitted diseases clinic.

Urethral specimens from 480 heterosexual patients were examined for Chlamydia trachomatis. Chlamydia were isolated from 32.7% of men with non-specific urethritis (NSU), from 16.1% of men with gonorrhoea, and from 4.1% of men without urethritis. Chlamydial isolation was not related to duration of symptoms, presence of discharge, or past history of attendance at the clinic. Urine from 176 heterosexual patients was examined for Ureaplasma urealyticum. Ureaplasmas were present in 53.8% of men with NSU, in 28% of men with gonorrhoea, and in 32.9% of men with no urethritis. Detection rates for ureaplasmas in patients with chlamydia-negative and chlamydia-positive NSU were similar, but ureaplasmas were present in significantly greater numbers in patients with chlamydia-negative NSU than in those with chlamydia-positive NSU.

Animals↗