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Biomedical subjects

H Smith

Publications and source records attributed to H Smith.

At least 523 records · Page 29Linked to original sources
PubMed1981

Role of computed tomography in the management of infectious disease.

All cases referred for computed tomography (CT) from a 48-bed infectious disease unit over a 3-year period were reviewed. Thirty patients were examined on 45 occasions with head and body cases approximately equal in number. Positive diagnoses were made in 38 examinations (84%), although this included 3 incidental findings. The most common indication for CT was exclusion of cerebral abscess presenting as meningitis (11 cases). The most common disease was tuberculosis (12 cases), although a wide spectrum of disease including four noninfective cases was encountered. CT made a direct contribution to the management of patients with meningitis, encephalitis, cerebral abscess, septicemia, hepatic abscess, tuberculosis, and lymphoma. Although CT was only utilized in a small proportion of patients admitted to this unit, the technique provided valuable information in the management of a number of problematic cases.

Abscess↗
PubMed1981

A method for assessing the quality of a randomized control trial.

A system has been constructed to evaluate the design, implementation, and analysis of randomized control trials (RCT). The degree of quadruple blinding (the randomization process, the physicians and patients as to therapy, and the physicians as to ongoing results) is considered to be the most important aspect of any trial. The analytic techniques are scored with the same emphasis as is placed on the control of bias in the planning and implementation of the studies. Description of the patient and treatment materials and the measurement of various controls of quality have less weight. An index of quality of a RCT is proposed with its pros and cons. If published papers were to approximate these principles, there would be a marked improvement in the quality of randomized control trials. Finally, a reasonable standard design and conduct of trials will facilitate the interpretation of those with conflicting results and help in making valid combinations of undersized trials.

Clinical Trials as Topic↗
PubMed1981

Female sexual arousal: relation between cognitive and genital assessments.

Evidence from the literature concerning the relation between subjective and physiologic assessment of sexual arousal in women is sparse and inconsistent. This study assessed the relation between self-report of arousal and changes in vaginal vasocongestion in 30 nondysfunctional women during the follicular, ovulatory and luteal phases of one menstrual month. Sexual arousal, a woman's emotional response to an erotic situation, was defined as the current momentary level of excitation in response to standardized stimuli. Dependent measures of sexual arousal included a scaled subjective assessment, genital pulse amplitude, and time above a criterion level of increased vasocongestion. Significant individual differences in sexual arousal were found with all measures. Evidence of construct validity was found for the concept of sexual arousability: arousal responses were found to be highly correlated across three stimulus conditions in each laboratory session. Erotic tape recordings elicited more arousal than fantasies. Subjective reports of degree of sexual arousal were all positively correlated with objective assessments of sexual arousal, but few correlations reached significant levels; subjective-physiologic correlations were higher when arousal was elicited by fantasy than when the stimulus was an erotic tape and during the luteal phase of the menstrual cycle.

Adult↗
PubMed1981

Hydrogenated oils and fats: the presence of chemically-modified fatty acids in human adipose tissue.

A total of 231 samples of adipose tissue has been analyzed for trans unsaturated acids which arise in large measure via consumption of hydrogenated fat; 136 specimens derived from patients who had died of ischemic heart disease (cases), the remainder being controls. They have also been analyzed by gas-liquid chromatography which gave information regarding the amounts of 1) "higher acids"--C20 plus C22 acids, mainly monoenoic--which derive from hydrogenated marine oils present in high amounts in certain margarines in the United Kingdom, and 2) "lower acids"--14:1 plus odd-numbered and branched chain acids in the C15 to C17 range--which are present in hydrogenated fat in lower amounts than in, say, butter-fat. Values of trans unsaturated acids tend to be higher, and values of lower acids lower for cases than controls, but we cannot at present conclude that these differences are statistically significant. Case versus control levels in respect of higher acids and linoleic acid do not appear to be significantly different.

Adipose Tissue↗
PubMed1981

Resistance of virulent and attenuated strains of Candida albicans to intracellular killing by human and mouse phagocytes.

Blastospores of two strains (no. 19321 and no. 19273) of Candida albicans that were obtained from patients with vaginal thrush and were virulent for mice showed no significant difference in degree of resistance to phagocytosis by human and mouse phagocytes (mostly polymorphonuclear) compared with blastospores of two strains (no. 22114 and no. 21462) that were isolated from patients with transient candidemia and were attenuated for mice. In contrast, more blastospores of the virulent strains survived intracellularly than did those of the attenuated strains over a 2-hr period, after which the surviving blastospores began to form germ tubes. Heterogeneity in the populations of blastospores was suggested, because progeny from surviving blastospores of attenuated strain no. 22114 behaved similarly to virulent strains in tests with human and mouse phagocytes and in virulence tests in mice.

Animals↗
PubMed1981

Production of germ tubes by virulent and attenuated strains of Candida albicans.

Two strains (no. 19321 and no. 19273) of Candida albicans that were obtained from patients with vaginal thrush and were virulent for mice formed germ tubes after incubation in fresh mouse serum and mouse kidney extract more rapidly and to a greater extent than did two strains (no. 22114 and no. 21462) that were isolated from patients with transient candidemia and were attenuated for mice. After incubation in fresh human serum, the strain differences in germination were not as marked although the pattern was similar. Synchronous cultures of strains no. 19321 and no. 22114 showed differences similar to those shown by asynchronous cultures in the mouse and human sera and in the mouse kidney extract. The viability of the strains was maintained in all three types of media; thus, nonspecific humoral defense mechanisms had little effect on the attenuated strain.

Animals↗
PubMed1981

Sexual arousability and the menstrual cycle.

Using a balanced experimental design, 30 regularly cycling woman not using oral contraceptives, aged 20 to 30 years, were assessed in a laboratory setting during the follicular, ovulatory, and luteal phases. Sexual arousal was measured by self-report and by photoplethysmographic recordings of vaginal vasocongestion. Plasma estradiol, progesterone, and testosterone were determined by radioimmunoassay. There were marked and consistent individual differences among the women in their sexual arousability. Subjective reports of sexual arousal did not differ among menstrual cycle phases, by physiologic arousal did vary with significantly higher mean levels of arousal occurring during the follicular and luteal phases than during the ovulation phase. While hormones fluctuated predictably with menstrual cycle phase, there were wide individual differences in absolute values among women. The correlations between estradiol, progesterone and testosterone and the subjective and objective assessments of arousability were mainly low and insignificant. Some evidence suggestive of a relation between testosterone and sexual arousability was observed with three subgroups of woman were formed on the basis of relative average testosterone concentrations.

Adult↗
PubMed1981

Differential distribution of virus and histological damage in the lower respiratory tract of ferrets infected with influenza viruses of differing virulence.

The distribution of four strains of influenza virus [A/PR/8/34 (H0N1) and clone 64d (attenuated for ferrets) and clones 64c and 7a (virulent for ferrets) of the recombinant virus A/PR/8/34--A/England/939/69 (H3N2)] in the lower respiratory tract (trachea, bronchi and the hilar, intermediate and outer alveolar zones of the lung) of ferrets was monitored daily for 4 days after intranasal inoculation. On day 1, some animals had high virus titres in all the tissues but in other animals virus was undetectable, irrespective of the virus strain. Two days after inoculation increase of virus contents of all tissues tended to be restricted. On days 3 and 4, the virulent clones (64c and 7a), in contrast to the attenuated strains (A/PR/8/34 and clone 64d), consistently infected the lower respiratory tissues. However, for all infected animals the virus contents of the hilar zones of the lungs were higher than those in the intermediate zones, while the alveolar zones were relatively free from virus. Quantitative estimations of the mild histological damage occurring in the lower respiratory tract 3 to 6 days after inoculation also indicated that bronchial and bronchiolar tissue were more susceptible to influenza virus than alveolar tissue and that clones 64c and 7a produced more damage than the other two strains. In agreement with the relative viral contents of clones 64c and 7a in the bronchi and in the hilar and intermediate zones of the lung, clone 64c produced more damage than clone 7a in the bronchi and less in the bronchioles of the lung parenchyma.

Animals↗
PubMed1981

Factors affecting the induction of phenotypically determined serum resistance of Neisseria gonorrhoeae grown in media containing serum or its diffusible components.

Phenotypically determined resistance of gonococci to killing by normal human serum can be generated by growth of susceptible organisms in media containing guinea pig, calf or human serum. However, even in the best medium tested, i.e. defined medium containing 50% (v/v) guinea pig serum, resistance was greatly reduced after 24 h incubation and the maximum number of colony-forming units generated was 10(7) to 10(8) ml-1. Resistance was not acquired after incubation in guinea pig serum at low temperature (8 degrees C), supporting previous indications that metabolic activity was necessary for the generation of resistance. Alteration of the concentration of glutamine, proline, lactate or iron had little or no effect on the generation of serum resistance under the conditions used. Optimum conversion to resistance occurred at pH 6.0 to 6.5 and both non-diffusible and diffusate fractions of dialysed guinea pig serum promoted resistance. Furthermore, resistant organisms could be produced by incubation in defined medium containing the diffusate from guinea pig serum and 0.1% bovine serum albumin, a step which should facilitate identification of the resistance-promoting factor.

Blood Bactericidal Activity↗
PubMed1981

Investigation of the determinants of the survival of Neisseria gonorrhoeae within human polymorphonuclear phagocytes.

In studies aimed at identifying the determinants responsible for the ability of gonococci to survive and grow within human phagocytes, the reduction of intracellular survival of phagocyte-resistant gonococci by prior treatment of the bacteria with homologous antiserum provided two indirect means of testing for possible determinants. First, surface washes of the resistant gonococci and fractions of these extracts were examined for ability to neutralize the above effect of antisera. Second, antisera raised to purified surface components of the resistant organisms were examined for ability to promote intracellular killing. A combination of these methods indicate that the aggressins were not pili but components of the outer membrane. A surface wash of a phagocyte-resistant, pilated strain, BS4 (agar), neutralized the activity of homologous antisera before and after centrifuging at 20 000 g, but pili separated from the supernatant did not. A corresponding supernatant from the surface wash of a phagocyte susceptible strain, BSSH, had little neutralizing ability. Antisera to pili failed to reduce intracellular survival of resistant gonococci, whereas antisera against outer membrane vesicles did so. Finally, the neutralizing activity of the surface wash supernatant was removed by centrifugation after treatment with wheat germ agglutinin, which precipitates outer membrane vesicles.

Antigens, Bacterial↗
PubMed1981

Induction of phenotypically determined resistance of Neisseria gonorrhoeae to human serum by factors in human serum.

Of 47 human sera tested, 13 converted serum-sensitive gonococci [strain BS4 (agar)] to serum resistance in vitro in 3 h at 37 degrees C, as had previously been demonstrated for most samples of guinea pig serum. The resistance-inducing activity of human serum was lower than that of guinea pig serum but, like the latter, did not operate at 8 degrees C, was greater at pH 6.6 than at pH 7.1, was increased by freezing and thawing, and depended on high and low molecular weight serum fractions; the latter fraction had a molecular weight between 1000 and 5000, and was acid- and heat-labile.

Blood Bactericidal Activity↗
PubMed1981

Immunochemical evidence for phytochrome regulation of the specific activity of ascorbate oxidase in mustard seedlings.

A monospecific antiserum to a Cucurbita ascorbate oxidase was shown to cross-react with the mustard enzyme. Purified antiserum was used in rocket immunoelectrophoresis plates to measure the amount of ascorbate oxidase protein in mustard cotyledon and hypocotyl extracts. On transfer from darkness to far-red light and activity of the enzyme in expanding cotyledons increased but the amount of enzyme protein remained the same. Unimbibed mustard seeds were shown to contain the same amount of antigenic protein as expanding cotyledons although in the seeds the enzyme was inactive. In hypocotyls continuous far-red light treatment also led to an increase in ascorbate oxidase activity; in this case there was also an increase in enzyme protein although this was relatively small. The results are discussed in relation to the mechanism by which phytochrome may control the activity of this enzyme.

Antigen-Antibody Complex↗
PubMed1981

Outcome of alcoholism treatment among 5578 patients in an urban comprehensive hospital-based program: application of a computerized data system.

The Elmhurst Alcoholism Program data system relates fraction of time patients are in remission to length of time they are know, and permits a systematic search for groups of variables which predict greater abstinence rates. Our program (inpatient detoxification ward, multidisciplinary outpatient clinic, and halfway house) sets abstinence as a goal. After initial data collection (social and demographic variables, income, education, residence, drinking and drug history, legal problems, and prior treatment), we collect data at 30 days after admission and at 2- or 3-month intervals thereafter from all patients who remain in contact. Forty-five percent of all patients are lost before 30 days. Only 32% of those still under observation at 1 yr and 27% of those still under observation at 2 yr claim continual abstinence. From among many combinations of variables examined for predictive power, a group of five was chosen as best. Patients who at their first follow-up interview reported attending AA meetings and taking Antabuse and who in addition had a job at admission, were older, and were admitted through the clinic rather than through inpatient detoxification had a greater fraction of time abstinent. Nevertheless, the best cluster of predictor variables did not account for more than 25% of the variation in rates of abstinence. Many social variables are not independent, and some may merely be indicators of duration or severity of alcoholism. Contemporary alcoholism treatment is, at best, of limited effectiveness.

Actuarial Analysis↗
PubMed1981

Bromine and selenium in human aorta.

The bromine and selenium concentrations of healthy and atheromatous human aorta and of other organs are reported. No relation between age and concentration in the aorta is found. The selenium levels of the aorta are similar to those of other internal organs; the content of the three layers show no significant differences. The bromine concentrations of the media are higher than those of the other layers, which are similar to those of the internal organs. A possibly greater concentration of bromine in atheromatous medial tissue is indicated.

Adolescent↗
PubMed1981

Hemoglobin Brisbane: beta68 Leu replaced by His. A new high oxygen affinity variant.

Hemoglobin Brisbane is a new hemoglobin variant which produces a mile erythrocytosis. It is not detectable by electrophoresis at pH 8.6 or by isoelectric focusing but it is mildly unstable and gives a positive result with standard stability tests. The new hemoglobin has increased oxygen affinity and reduced co-operativity with a normal Bohr effect and 2,3-DPG binding. Structural analysis shows that a histidine residue has replaced the leucine normally found at position beta 68 (E12).

Adult↗