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Biomedical subjects

J Smith

Publications and source records attributed to J Smith.

At least 667 records · Page 37Linked to original sources
PubMed1994

Variations in fluconazole susceptibility and electrophoretic karyotype among oral isolates of Candida albicans from patients with AIDS and oral candidiasis.

DNA subtyping by pulsed-field gel electrophoresis and in vitro susceptibility testing were used to study strain variation and fluconazole resistance in Candida albicans isolates from patients with AIDS undergoing azole (fluconazole and clotrimazole) therapy for oropharyngeal candidiasis. A total of 29 patients suffered 71 episodes of oropharyngeal candidiasis. Overall, 121 isolates of C. albicans recovered throughout the course of treatment of each infection were available for further characterization. DNA subtyping revealed a total of 61 different DNA subtypes. In vitro susceptibility testing of the 121 isolates by using proposed standard methods of the National Committee for Clinical Laboratory Standards revealed MICs of fluconazole ranging from < or = 0.125 to > 64 micrograms/ml. The MIC for 50% of isolates tested was 0.25 microgram/ml, and the MIC for 90% of isolates tested was 8.0 micrograms/ml. MICs were > or = 64 micrograms/ml for only 7.4% of the isolates tested. The majority (62%) of the patients with oropharyngeal candidiasis and undergoing azole therapy were infected or colonized with more than one DNA subtype, and the introduction or selection of strains with a more resistant DNA subtype during the course of fluconazole therapy was not uncommon. With one exception, this did not appear to have an adverse effect on clinical outcome. In contrast, for patients with AIDS and oropharyngeal candidiasis infected with a single DNA subtype of C. albicans, an increase in fluconazole MICs for the infecting strain was rarely demonstrated over the course of therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Novel, ultrasensitive, Q-beta replicase-amplified hybridization assay for detection of Chlamydia trachomatis.

A sensitive, nonisotopic hybridization assay termed "dual capture" is described. The assay rapidly and specifically detects very low levels of target nucleic acids and organisms. The assay is based on the principles of sandwich hybridization, reversible target capture, and Q-Beta replicase amplification. The assay can be completed in less than 4 h, and in the described model format, it detects Chlamydia trachomatis rRNA or rDNA. Up to 96 samples can be analyzed simultaneously. The assay employs two types of probes: a test-specific capture probe, which mediates the cycling of the target probe complex on and off derivatized magnetic beads, and a replicatable RNA detector molecule containing a sequence complementary to and adjacent to the capture probe site on the target. Following reversible target capture, detection of the signal is accomplished by replication of the detector molecule by Q-Beta replicase in the presence of propidium iodide. A specific assay signal can be detected from as few as 1,000 molecules above the background. In a limited study of 94 urogenital samples the assay detected five of the six culture-positive samples and did not detect the C. trachomatis target in 85 of the 88 culture-negative samples.

Base Sequence↗
PubMed1994

Costal and crural diaphragm function during panting in awake canines.

During natural panting for thermal regulation, the pattern of activation of the major respiratory muscles, including costal and crural diaphragm segments, is not known. We measured diaphragm segmental length, shortening, and electromyographic (EMG) activity in five chronically implanted canines awake and breathing spontaneously at rest and during a mild dry heat stress. During panting, minute ventilation increased fourfold from 5.07 l/min and respiratory rate increased from 16.9 to 192.8 breaths/min or 3.2 Hz. During panting, end-expiratory length of both costal and crural segments decreased, concurrent with significant increases in end-expiratory EMG. With the onset of panting, tidal costal shortening decreased significantly from 6.29% of end-expiratory length to 3.54%, whereas crural shortening decreased from 6.04 to 2.46%. Meanwhile, segmental EMG tended to increase during panting. During panting, intrabreath costal and crural segmental function revealed differential activation; the costal segment shortened in concert with inspiratory flow, whereas peak crural shortening occurred in expiration, almost 180 degrees out of phase with costal. The divergence in segmental shortening during panting was accompanied by a lesser shift in timing of segmental EMG. In the awake spontaneously panting canine, asynchronous costal and crural shortening may enhance gas mixing in a manner analogous to high-frequency ventilation.

Animals↗
PubMed1994

Transurethral microwave thermotherapy versus transurethral catheter therapy for benign prostatic hyperplasia.

Transurethral microwave thermotherapy (TUMT) is a single outpatient treatment for benign prostatic hyperplasia. It produces good symptomatic relief but minimal objective improvement in mean flow rates. We wished to evaluate the placebo effect of the transurethral catheter. We evaluated 40 patients with outflow obstruction, 20 had TUMT for 1 h and 20 had a catheter placed in the urethra without treatment for 1 h. Urinary flow rates improved in both groups (12.8-14.6 with TUMT, 10.0-12.4 with catheter). Significant reduction from pretreatment values occurred in symptom scores and postvoid residual urine volume in both groups following treatment. The subjective results of TUMT and the placebo effect seen in the catheter group cast doubt on our understanding of the mechanism of action of TUMT.

Humans↗
PubMed1994

Schizophrenics remanded to the Forensic Psychiatric Institute of British Columbia, 1975-1990.

Clinical and legal data were collected on 1265 schizophrenic patients remanded to a maximum security hospital, for psychiatric evaluation of fitness to stand trial. Schizophrenics accounted for over half of the remand population. When compared to the nonschizophrenic group, they had more previous admissions to the Forensic Psychiatric Institute and the Provincial Mental Hospital. They were also more likely to be found unfit to stand trial or to have their charges stayed by the Crown. However, approximately half of the schizophrenics in this study returned to Court, fit to stand trial and with no further psychiatric treatment provided. This study raises major questions about the purpose and value of remanding schizophrenics to a maximum security hospital for in-patient fitness evaluations.

Adolescent↗
PubMed1994

The plantar plate of the lesser toes: an anatomical study in human cadavers.

The purpose of this study was to evaluate the anatomic structure and biochemical composition of the plantar plate of the lesser toes. Fresh frozen-human cadaveric feet were used to study 20 metatarsophalangeal and proximal interphalangeal plantar plates. The observations of foot dissections were compared with the finger volar plate. The plantar plate of the toe is a rectangular structure with a stout distal insertion and relatively flimsy proximal origin. The anatomic relationships to adjacent structures and composition are similar between the volar plates of the fingers and plantar plates of the toes. The plantar plate is known to experience extension forces that the volar plate does not experience. The weightbearing nature of the foot and forces imposed by toe-off may create chronic hyperextension of the metatarsophalangeal joint and predispose the plantar plate to attenuation or rupture, thus leading to instability of the metatarsophalangeal joint. These findings may explain in part the clinical condition of spontaneous metatarsophalangeal joint dislocation, most commonly found in the second toe.

Collateral Ligaments↗
PubMed1994

Schizophrenia and substance abuse.

BACKGROUND: Recent research from North America has demonstrated higher than expected rates of drug and alcohol abuse among the seriously mentally ill. Schizophrenics appear to be particularly susceptible to the negative effects of substance abuse. These include psychiatric and social complications, with antisocial behaviour, particularly violence emerging as one of the most worrying features. This review examines the strength of the association and explores the possible explanations for the apparent link between schizophrenia, substance abuse and violence. METHOD: The literature was searched using Medline, supplemented with a manual literature search. RESULTS: Very few articles specifically approached the problem of violence among substance abusing schizophrenics, but over 80 papers were identified which were helpful in exploring the link between dangerous behaviour and substance abuse by schizophrenics. CONCLUSIONS: While there is circumstantial evidence to support the hypothesis that schizophrenics who abuse drugs or alcohol are at an increased risk of behaving violently, longitudinal studies are required to facilitate a better understanding of the mediating mechanisms.

Combined Modality Therapy↗
PubMed1994

Childhood sexual experiences with adults: adult male psychiatric patients and general practice attenders.

BACKGROUND: Sexual abuse of male children is now believed to be common, and there may be links to adult psychiatric disorders. METHOD: Recollections of sexual experiences with adults in childhood were studied systematically in 115 men attending general practice surgeries and 100 male psychiatric patients. RESULTS: The latter reported more frequent and more serious events before the age of 13 than the general practice attenders. No significant difference was detected for events between the ages of 13 and 15. CONCLUSIONS: Childhood sexual abuse before the age of 13 may be associated with later psychiatric disorders, although the nature of the association remains uncertain. The possible significance of such experiences should be considered when assessing men with mental disorders.

Adolescent↗
PubMed1994

Human fetal membrane contribution to the prevention of parturition: uterotonin degradation.

This investigation was conducted to evaluate the potential capacity of the human fetal membranes-decidua parietalis, and in particular the chorion laeve, to degrade uterotonins that are produced in amnion, are present in amniotic fluid, or both. The four uterotonins that have been evaluated most frequently as myometrial contractants potentially involved in the initiation of human parturition are prostaglandins, oxytocin, endothelin-1, and platelet-activating factor. We assessed the levels of mRNA and the specific activities (SAs) of enkephalinase (the plasma membrane endopeptidase that degrades endothelins) and prostaglandin dehydrogenase (PGDH) in human fetal membranes, i.e. amnion and chorion leave, and in decidua parietalis. The SA of oxytocinase (which inactivates oxytocin) in these tissues also was determined. The SA of enkephalinase in chorion laeve from all anatomical sites (singleton and diamnionic-dichorionic twin placentae) in all pregnancies studied (mean +/- SEM, 95 +/- 7.9 ng/min.mg protein; n = 28) is similar to that in human fetal kidney (89.5 +/- 2.8; n = 6). Kidney tissue is believed to be one of the richest sources of enkephalinase. The SAs of enkephalinase in amnion (18.3 +/- 2.3 nmol/min.mg protein; n = 29) and in decidua parietalis (31.8 +/- 6.7; n = 20) also were high, but significantly less than that in chorion leave. The level of enkephalinase mRNA in chorion laeve in singleton pregnancies is high, as is the SA of enkephalinase (111.9 +/- 10.6 nmol/min.mg protein; n = 17). In paired chorion laeve tissues from five diamnionic-dichorionic twin placentae, the SAs of enkephalinase in reflected chorion laeve (74 +/- 12.8; P < 0.06 compared with singletons) and fused chorion laeve (64.8 +/- 6.5; P < 0.001 compared with singletons) were similar. The SA of PGDH in reflected chorion leave (46.3 +/- 6.9 nmol/min.mg protein; n = 19) was significantly greater than that in decidua (16 +/- 5.5; n = 15). There was a significant correlation between the levels of PGDH mRNA and PGDH enzyme SA. In fused chorion laeve of diamnionic-dichorionic twin placentae, the SA of PGDH (14.9 +/- 7.3; n = 4) was much less than that in reflected chorion laeve of the same twin pregnancy (70.5 +/- 14.7; n = 4). PGDH mRNA was not detectable in amnion tissue (n = 5) by northern analysis, and the SA of PGDH (< 1.2 +/- 1.0; n = 6) in amnion was undetectable or near the lower limit of assay detection.(ABSTRACT TRUNCATED AT 400 WORDS)

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1994

EVIDENCE FOR HYDRATION-DEPENDENT CLOSING OF PORE STRUCTURES IN THE CUTICLE OF PERIPLANETA AMERICANA

Integumental electrical resistances were measured on the antenna, pronotum, forewing, second abdominal tergite, fifth abdominal sternite and the femur of the third leg in restrained male and female Periplaneta americana. The same measurements, excepting those on antenna and wing, were made on last-instar nymphs. Electrical contact was made through two externally applied glass tubes filled with cockroach Ringer with a combined contact area of about 2 mm2. Resistances corresponding to current flows through two thicknesses of integument were measured using a current-clamping amplifier. Calculated electrical conductances tended to be higher in the antennae, pronotum and abdominal tergites than in the legs and wings. Conductances of the pronotum and abdominal tergites were significantly higher (P<0.001) in males than in females. The literature suggests that male abdominal tergites are the site of sex pheromone production. In nymphs as well as adults, the conductances of all areas, except the antennae of males, decreased following dehydration and a decline in animal water content. In most cases the magnitude of the decrease was tightly correlated with initial hydrated conductance. The data suggest that variations in regional conductances in hydrated animals are principally due to differences in dermal gland density. We argue that the decrease in conductance following dehydration is evidence of a mechanism closing dermal gland openings in times of water stress.

Journal Article↗
PubMed1994

Modeling the relationship between clinical, microbiologic, and immunologic parameters and alveolar bone levels in an elderly population.

A cross-sectional periodontal study of 74 subjects aged 65 to 75 years was performed. Clinical data were collected and related to microbiological and immunological data. A statistical model (step-wise multiple regression) of factors related to bone loss was created initially using clinical data only; then by adding either the microbiologic or immunologic data; and then by using clinical, microbiologic, and immunologic data together. When only clinical data were considered, three factors were found to have significant positive correlations with bone loss. Tooth mobility accounted for 17% of the variability in the alveolar bone level measurements, probing depth for 12%(r2), and plaque index for 3%, for a total of 32% of the variability explained by these clinical factors. Tooth mobility and probing depth were clinical factors which remained significant in the model when the microbiological data were also considered. As percentages of the total cultivable microbiota, E. corrodens (r2 = 14%) and black-pigmenting Prevotella intermedia (r2 = 4%) correlated positively with alveolar bone loss. The addition of the microbiologic data only increased the r2 to 33%. When immunological data were considered with the clinical data, pocket depth and tooth mobility were the clinical parameters which remained in the model. IgG antibody levels to P. gingivalis W83 and/or 381 (r2 = 24%) A. actinomycetemcomitans 627 (r2 = 2%) were the significant immunologic measures having a positive correlation with bone loss. Anti-F. nucleatum levels had a significant negative correlation. A total of 50% of the variability in alveolar bone level was accounted for in the model by the addition of specific serum antibody levels to subgingival plaque microorganisms. When clinical, microbiological, and immunological measurements were all considered together, antibody to P. gingivalis W83 and/or 381 (r2 = 42%), percentage of B-lymphocytes (r2 = 3%), probing depth (r2 = 4%), anti-E. corrodens levels (r2 = 2%), and anti-P. gingivalis 33277 levels (r2 = 4%) all had significant positive correlation with loss of alveolar bone. The number of enteric bacteria, anti-F. nucleatum levels, and anti-P. intermedia levels each had a significant negative correlation with alveolar bone heights. The r2 for this model was 75%. These results indicated that antibody levels to subgingival plaque microorganisms and tooth mobility were the best predictors of bone loss in the elderly patients tested in this study.

Age Factors↗
PubMed1994

Grip strength in end stage renal disease.

The grip strength of 110 patients with end stage renal disease was measured. Their grip strength tended to be low compared with published norms. Significant correlations were found between the patients' grip strength and their gender, height, weight, and diabetic status. A regression equation including gender, height, and diabetic status as independent variables explained more than 40% of the variance in patients' grip strength.

Adult↗
PubMed1994

Complement-mediated cytotoxic activity of anti-heart antibodies present in the sera of patients with dilated cardiomyopathy.

A microcytotoxicity assay has been used to determine the cytotoxic activity of anti-heart antibodies which we have previously shown to be present with greater frequencies and reactivities in patients with dilated cardiomyopathy (DCM) than in patients with ischaemic heart disease (IHD). Serum samples from 45 patients with DCM and 43 patients with IHD were screened against W1, a transformed human fetal cardiac cell line and also against EA.hy 926, an endothelial and IBR3, a fibroblast cell line. In the presence of complement, sera from 28 (62%) DCM patients showed killing of the W1 cell line as compared to sera from 13 (30%) of IHD patients (p < 0.005) and 3 (15%) of normal individuals. In contrast, only 1 patient with DCM showed killing of the endothelial cell line and 1 patient with IHD showed killing of the fibroblast cell line. These results provide evidence for a complement-dependent, antibody-mediated mechanism of damage to cardiac myocytes which may contribute to the pathogenesis of DCM.

Adolescent↗