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Biomedical subjects

H Young

Publications and source records attributed to H Young.

At least 163 records · Page 9Linked to original sources
PubMed1989

Fluorescent monoclonal antibody test for the confirmation of Neisseria gonorrhoeae.

The Microtrak fluorescein labelled monoclonal antibody test for the culture confirmation of Neisseria gonorrhoeae was evaluated with 157 clinical isolates of oxidase-positive Gram-negative diplococci, including 110 strains of N. gonorrhoeae. Seventy-eight stock cultures of neisseria were tested to confirm the results from clinical samples. The test gave a specificity of 100% and sensitivity of 98%. Only four strains of the rare serovar Behj were non-reactive. As the prevalence of this serovar influences the utility of the test, the rarity of this serovar in different geographical locations is discussed.

Antibodies, Monoclonal↗
PubMed1988

Percutaneous gastrostomy: the Stanford experience.

Many techniques have been devised to provide enteral nutrition to the patient with cancer of the head and neck. No single technique will be adequate for all patients, but our experience with percutaneous gastrostomy has encouraged us to recommend it as a valuable alternative to conventional modalities. The charts of 156 patients, identified by computer-assisted search as having undergone gastrostomy at Stanford University Hospital or Palo Alto Veterans Administration Hospital from 1984 to 1987, were reviewed. Of these, 24 patients with a primary diagnosis of head and neck malignancy underwent percutaneous gastrostomy and form the basis for this study. Parameters evaluated included operation time, type of anesthesia, perioperative complications, and cost. Percutaneous gastrostomy can be performed under local anesthesia or at the time of routine head and neck procedures such as staging endoscopy. Our success with this technique leads us to recommend it as a valuable alternative for providing nutrition to head and neck cancer patients.

Adult↗
PubMed1988

A comparison of biscuits used in emergency relief feeding programmes in Ethiopia and eastern Sudan--1985/86.

Twenty-nine samples of food-aid biscuits were collected during a survey of feeding programmes in Ethiopia and Sudan. A further seven brands were included in the study but were not found in Ethiopia or Sudan. All but two brands were produced in Europe. Only 20 brands were recommended for use as emergency rations or as nutritious supplements; eight brands were similar to traditional baked biscuits and four were infant rusks. The compared biscuit characteristics included ingredients, energy density, unit size, protein content, fortification with vitamins and minerals and costs. A wide range in all characteristics was found. Biscuits high in protein tended to have a low energy density. Energy density and unit size influenced the volume eaten and ease of transport, storage and also distribution to recipients. The cost of energy (per 500 kcal) ranged between 14.0 p for baked biscuits and 47.5 p for the unbaked compressed products.

Bread↗
PubMed1987

Ciprofloxacin versus ampicillin and probenecid in the treatment of uncomplicated gonorrhoea in men.

Eighty-six men with uncomplicated gonorrhoea were entered into a study comparing the efficacy of a single oral dose of 250 mg of ciprofloxacin with a single oral dose of ampicillin 2 g and probenecid 1 g for urethral gonorrhoea and a course of ampicillin, 500 mg four times per day for five days in rectal and pharyngeal infection. Two patients were excluded. Of the remaining 84, 45 were treated with ampicillin and 39 with ciprofloxacin. In the ampicillin group there were two treatment failures out of 40 urethral infections. Three patients with rectal infection were cured. Only one patient out of three pharyngeal infections was cured. Ciprofloxacin cured all of 34 urethral and three rectal infections including one penicillinase producing strain of Neisseria gonorrhoeae (PPNG). Four of five pharyngeal infections were cured but there was one treatment failure. There were no major side effects in either treatment group. In conclusion, a single oral dose of 250 mg of ciprofloxacin is an effective treatment for uncomplicated gonorrhoea in men.

Ampicillin↗
PubMed1987

Characterisation of Branhamella catarrhalis and differentiation from Neisseria species in a diagnostic laboratory.

To distinguish Branhamella catarrhalis from Neisseria species a study of 140 strains was made on simple laboratory media, with particular reference to deoxyribonuclease (DNase) production, superoxol reaction, and growth characteristics. All 97 clinical isolates of B catarrhalis (58 of which were beta-lactamase positive) and eight strains of B catarrhalis from the National Collection of Type Cultures were DNase positive and superoxol positive. None grew on modified New York City medium, modified Thayer Martin medium, MacConkey agar, crystal violet blood agar, nor under anaerobic conditions. Of the 16 different non-pathogenic Neisseria species tested, all were DNase negative, eight (50%) were superoxol reaction negative, and 13 (81%) grew on crystal violet blood agar. Using simple laboratory media, DNase, and superoxol tests, it was possible to identify B catarrhalis and to distingish it from pathogenic and non-pathogenic Neisseria species.

Deoxyribonucleases↗
PubMed1987

Serological classification of Neisseria gonorrhoeae with monoclonal antibody coagglutination reagents.

A total of 357 clinical isolates of Neisseria gonorrhoeae from 286 patients were classified serologically using two independently developed panels of monoclonal coagglutination reagents. The Pharmacia (Ph) Diagnostics panel comprised 14 reagents, five specific for serogroup WI strains and nine specific for serogroup WII/III strains, whereas the Genetic Systems (GS) panel comprised 14 reagents, seven specific for serogroup WI strains and seven specific for serogroup WII/III strains. Serogroup WI represented 45% and WII/III represented 55% of the patients. Using the monoclonal antibody reagents, the serogroups could be further subdivided into so-called serovars. The Ph reagents identified four WI serovars and 21 WII/III serovars, whereas the GS reagents identified 10 WI serovars and 18 WII/III serovars. By combining the results obtained with each panel, 15 Ph/GS WI serovars and 33 Ph/GS WII/III serovars were recognised. In the WI isolates, one predominating serovar was recognised, whereas in the WII/III isolates, no single serovar predominated and a much greater variety of serovars was identified. The serovar patterns for men and women patients were very similar, except for one WII/III serovar that was 10 times more common in isolates from men than from women. Most isolates from different anatomical sites in the same patient were of the same serogroup and serovar. Two double infections were found. One patient had a genital infection with serogroup WII/III and a rectal infection with serogroup WI. Another patient with genital, rectal, and throat infections with serogroup WI was found to have gonococci of different GS serovars at each site. It was concluded that the level of discrimination achieved with the monoclonal antibody reagents should prove to be valuable in studying the micro epidemiology of gonococcal infection.

Agglutination Tests↗
PubMed1987

The number and distribution of muscle spindles and tendon organs in the peroneal muscles of the cat.

An analysis has been made of the numbers and distributions of muscle spindles and tendon organs in the three peroneal muscles of the lower hindlimb of the adult cat. Both peronei brevis and tertius were richly supplied with spindle capsules and tendon organs in comparison with peroneus longus and other muscles of the cat's lower hindlimb. A large number of the capsules in each muscle was involved in tandem linkages, some of these capsules comprising only a bag and some chain fibres. Such capsules were especially prevalent in peroneus tertius. The numbers of extrafusal muscle fibres inserting into each tendon organ indicated that the activity of each motor unit should be monitored by at least one tendon organ. The distributions of the receptors are discussed in relation to the proportion and density of oxidative muscle fibres.

Animals↗
PubMed1986

Leucocytes in the ejaculate from fertile and infertile men.

The presence of leucocytes and their subpopulations was studied in the ejaculate from 69 men with an infertile marriage and 12 fertile men. Monoclonal antibodies specific for human leucocytes were used in an immunoperoxidase technique. In addition to the standard sperm analysis, each specimen was also tested for sperm antibodies, aerobic and anaerobic microorganisms, Ureaplasma urealyticum and Chlamydia trachomatis. Leucocytes were found in large numbers in the fertile men compared with the patients. Lymphocytes were found in 20% of the patients. Micro-organisms were cultured from a similar proportion of both groups. We found no correlation between leucocyte counts, sperm density and motility, sperm antibodies and growth of micro-organisms. Our results cast doubt on the conventional criteria of subclinical genital tract infection, namely positive culture and excess leucocyte counts.

Ejaculation↗
PubMed1986

Immediate functional recovery after six hours of regional ischemia by careful control of conditions of reperfusion and composition of reperfusate.

This study tests the hypothesis that irreversible muscle damage does not occur after as long as 6 hours of ischemia before reperfusion, immediate functional recovery is possible by controlling the conditions of reperfusion during total vented bypass and the composition of the reperfusate with substrate-enriched blood cardioplegic solution, and such control can be accomplished without thoracotomy. Of 43 dogs undergoing 2 to 6 hours of left anterior descending coronary occlusion, seven were studied by ultrastructural and mitochondrial analyses after 6 hours of regional coronary occlusion without reperfusion. Sixteen other dogs were reperfused with normal blood, with the heart in the beating state after 2 to 4 hours of ischemia, and 20 dogs received regional substrate-enriched blood cardioplegic reperfusion after 2 to 6 hours of ischemia for 20 minutes during total vented bypass accomplished through the femoral artery, femoral vein, and transaortic left ventricular venting. Six hours of ischemia without reperfusion caused minimal changes in mitochondrial structure and retained mitochondrial adenosine triphosphate production capacity at 64% of control values despite complete depletion of tissue adenosine triphosphate. Reperfusion with normal blood in the beating, working hearts caused extensive structural damage, reduced reflow, and failed to restore contractility in any instance (-27% systolic shortening, p less than 0.05). In contrast, regional cardioplegic reperfusion during total vented bypass at 2, 4, and 6 hours caused 52 +/- 3%, 41 +/- 7%, and 21 +/- 6% immediate recovery of regional contractile function. The seven hearts reperfused at 6 hours of ischemia had more segmental shortening (21% versus -27%, p less than 0.05), less edema (81% versus 83% water content, p less than 0.05), and more postischemic flow (57 versus 18 ml/100 gm/min in subendocardial muscle, p less than 0.05) than did 2-hour controls, and postischemic ultrastructure was not altered by reperfusion. Six hours of ischemia does not produce irreversible damage, and immediate recovery of contractile function is possible if the conditions of reperfusion are controlled with total vented bypass and a regional substrate-enriched blood cardioplegic solution is administered. Such control can be obtained by the peripheral cannulation technique.

Animals↗
PubMed1986

Biochemical studies: failure of tissue adenosine triphosphate levels to predict recovery of contractile function after controlled reperfusion.

This study tests the hypotheses that postischemic adenosine triphosphate levels are unreliable predictors of functional recovery, myocardial adenosine triphosphate concentration of less than 2 mumol/gm does not indicate irreversible damage, mitochondrial adenosine triphosphate generating capacity can be nearly normal despite low levels of tissue adenosine triphosphate and the failure to replenish adenosine triphosphate after ischemia is due to depletion of the adenosine nucleotide pool, which can be replenished partially by exogenous precursors (e.g., 5-amino-4-imidazolecarboxamide ribotide [AICAR]). Myocardial adenosine triphosphate was depleted to less than 2 mumol/gm by either global ischemia (37 degrees C aortic clamping) or regional ischemia (acute coronary occlusion). Reperfusion was either with normal blood or with substrate-enriched blood cardioplegic solution during total vented bypass. Tissue adenosine triphosphate content and mitochondrial adenosine triphosphate generating capacity were measured, and functional recovery was determined by right heart bypass function curves or regional segmental shortening (ultrasonic crystals). Hearts undergoing 15 minutes of global ischemia and normal blood reperfusion had impaired functional recovery (stroke work index = 58 +/- 5%; p less than 0.05 of control) despite adenosine triphosphate concentration greater than 2 mumol/gm. Transmural mitochondrial State 3 respiration averaged 83% of control values despite adenosine triphosphate levels of 1 mumol/gm in hearts undergoing 45 minutes of 37 degrees C global ischemia and 2 additional hours of aortic clamping with multidose glutamate-enriched blood cardioplegia. AICAR increased adenosine triphosphate to 2 mumol/gm (p less than 0.05), but functional recovery was nearly complete (stroke work index = 94 +/- 2% of control) and was comparable with and without AICAR. Hearts undergoing 4 hours of regional ischemia recovered 31 +/- 5% systolic shortening after controlled reperfusion despite tissue adenosine triphosphate less than 0.5 mmol/gm (15% of control), and they retained 63% adenosine triphosphate generating capacity. Postischemic adenosine triphosphate levels correlate poorly with functional recovery, and adenosine triphosphate levels less than 2 mumol/gm do not indicate irreversible ischemic injury. Low postischemic levels may be repleted partially by adenine nucleotide precursor supplementation (AICAR).(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphate↗
PubMed1986

Electron microscopic studies: importance of embedding techniques in quantitative evaluation of cardiac mitochondrial structure during regional ischemia and reperfusion.

This study applies the low protein-denaturation embedding technique for mitochondrial preparation to analyze control cardiac tissue, heart muscle subjected to 6 hours of regional ischemia without reperfusion, and myocardial tissue subjected to 4 to 6 hours of ischemia followed by reperfusion either with normal blood, with the heart in the beating, working state, or with substrate-enriched blood cardioplegia during total vented bypass. Parallel specimens of cardiac tissue were analyzed for ultrastructure by the conventional osmium tetroxide fixation method. Results following conventional tissue preparation with osmium tetroxide showed extensive ultrastructural damage in all hearts subjected to ischemia, with no correlation between ultrastructural findings and methods of reperfusion or functional recovery. In contrast, results following tissue preparation by the low protein-denaturation method showed reperfusion with normal blood in working hearts to cause severe mitochondrial damage, cardiac mitochondria that were intact structurally after 6 hours of ischemia and after controlled reperfusion, a logical sequence of mitochondrial structural changes that may lead to irreversibility, and a new method of quantification of such changes.

Animals↗
PubMed1986

Reperfusate composition: interaction of marked hyperglycemia and marked hyperosmolarity in allowing immediate contractile recovery after four hours of regional ischemia.

This study tests the hypothesis that improved muscle salvage after prolonged ischemia (4 hours) occurs when the substrate-enriched blood cardioplegic solution is markedly hyperglycemic (greater than 400 mg/dl) and markedly hyperosmotic (greater than 400 mOsm). Thirty-five dogs underwent 4 hours of occlusion of the left anterior descending coronary artery and reperfusion during total vented bypass with substrate-enriched blood cardioplegic solution, in which the glucose concentration and osmolarity were varied in relation to one another. Spontaneous systolic shortening recovered consistently (31 +/- 6%) only when glucose was greater than 400 mg/dl and osmolarity was greater than 400 mOsm. The least recovery occurred (only one of six dogs recovering spontaneous shortening) when cardioplegic glucose was greater than 400 mg/dl and osmolarity was greater than 400 mOsm. Regional segments reperfused with our standard substrate-enriched blood cardioplegic solution had lower transmural flow rates following reperfusion (56 versus 87 ml/100 gm/min, p less than 0.05), markedly reduced mitochondrial State 3 and State 4 respiration in epicardial and endocardial muscle (p less than 0.05), and the most extensive histochemical evidence of damage (63% area of nonstaining versus area at risk, p less than 0.05). We conclude that markedly increased levels of osmolarity (greater than 400 mOsm) and glucose (greater than 400 mg/dl) improve the capacity of substrate-enriched blood cardioplegic solution to salvage myocardium after prolonged ischemia.

Animals↗
PubMed1985

Correlation of cell-envelope phenotypes of Neisseria gonorrhoeae with site of infection and serogroup.

The envelope phenotypes and coagglutination (CoA) W serogroups of 301 unselected clinical isolates of Neisseria gonorrhoeae were studied. Of the 287 isolates from infections acquired in the Edinburgh area, 252 (88%) were of the wild-type phenotype, 17 (6%) were of Env phenotype with increased permeability of the cell envelope, and 18 (6%) were of Mtr phenotype with reduced permeability of the cell envelope. Mtr strains were isolated significantly more often from homosexual men than from heterosexual men and women (p less than 0.001). Of the isolates from homosexual men there were considerably fewer Mtr phenotypes among rectal isolates than among urethral and throat isolates. All isolates from homosexual men, 57% from heterosexual men and 52% from women were of CoA serogroup WII (including WII/WIII). Although the Mtr phenotype was strongly associated with serogroup-WII isolates from homosexual men, there was no such correlation between the Mtr phenotype and serogroup-WII isolates from heterosexual patients. It is suggested that hydrophobic compounds in the rectal environment are not the major factor in selecting serogroup-WII strains of Mtr phenotype associated with homosexually acquired infection. The hypothesis that the Mtr phenotype and serogroup WII are selected independently as a result of a more general selective pressure such as antibiotic usage, common to all infected sites, is discussed.

Agglutination Tests↗