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Biomedical subjects

J M Knox

Publications and source records attributed to J M Knox.

At least 19 recordsLinked to original sources
PubMed1987

Familial dyskeratotic comedones. A report of three cases and review of the literature.

Three family members, at initial evaluation, had generalized comedonal lesions with histologic changes of acantholysis and dyskeratosis. A total of nine cases of this entity, termed familial dyskeratotic comedones, have been documented in the literature. It appears to have autosomal dominant inheritance and onset in childhood or adolescence. Lesions are asymptomatic except for occasional pruritus or inflammation, and general health is undisturbed. A history of acne vulgaris is seen in four of nine patients and is the only associated skin disease. Treatment with oral isotretinoin produced no improvement in two patients. Electron microscopy revealed changes similar to those seen in Darier's disease.

Acantholysis↗
PubMed1986

Acquired perforating disease in oil field workers.

Eight cases of an acquired perforating disease are reported in oil field workers who were exposed to drilling fluid. Analysis of the drilling fluid showed it to contain many components, including calcium chloride. Histopathologic study of patient lesions demonstrated transepidermal elimination of calcium. An in vivo mouse model was developed to study this phenomenon, which may represent a calcium-mediated perforating disorder.

Adult↗
PubMed1984

Chromomycosis. The association of fungal elements and wood splinters.

In two separate specimens received for histopathologic examination, pigmented fungal elements were found within or on embedded wood splinters associated with a foreign-body reaction. The fungus was found to be in direct contact with the surrounding dermis. These findings support the concept of inoculation as a pathogenetic mechanism in cutaneous chromomycosis.

Aged↗
PubMed1984

Paresthesia from cutaneous exposure to a synthetic pyrethroid insecticide.

Occupational exposure to fenvalerate, a synthetic pyrethroid insecticide, has been reported to cause paresthesia. An assay was devised in our laboratory for subjective grading of the sensation produced by the topical application of this compound. The present double-blind study compared human discrimination of topically applied technical fenvalerate, the heavy-ends fraction of fenvalerate, and ethyl alcohol (vehicle). Both forms of fenvalerate showed a statistically significant increase in inducing paresthesia over the vehicle alone. The onset of the cutaneous sensations occurred at one hour, peaked at three to six hours, and lasted approximately 24 hours. Numbness, itching, burning, tingling, and warmth were the most frequently reported sensations. The difference between the two fractions of fenvalerate was not statistically significant.

Ethanol↗
PubMed1983

The use of an immobilized enzyme nylon tube reactor incorporating a four enzyme system for creatinine analysis.

A single immobilized enzyme nylon tube reactor was produced incorporating a four enzyme system for the analysis of creatinine. The enzyme activity ratios in the coupling solution used to prepare the reactor were found to be of extreme importance in governing the activity of the latter. The reactor was incorporated into a continuous flow analysis system used to assay creatinine in urine samples and the results were correlated with a manual technique employing the same enzyme system in solution. The precision, correlation, high specificity, simplicity, and speed of the analysis were concluded to be factors in favor of the method's suitability for urine creatinine determinations.

Creatine Kinase↗
PubMed1981

The effects of neuroleptic drugs on 5-hydroxytryptamine induced platelet aggregation in schizophrenic patients.

1 The effects of treatment with a range of neuroleptic drugs on 5-hydroxytryptamine (5-HT) induced platelet aggregation in vivo were examined in a group of recently admitted psychiatric patients and in a larger group of chronic schizophrenic patients. 2 Five of seven recently admitted patients treated with chlorpromazine showed enhanced aggregation. Four of seven patients treated with fluphenazine, flupenthixol, trifluoperazine and haloperidol showed enhancement. 3 Enhanced aggregation responses were observed in only 20% of chronic schizophrenic patients being treated with a neuroleptic drug. 4 The relationship between changes in platelet aggregation and clinical changes in recently admitted patients was variable and platelet aggregation responses were not predictive of response to treatment. 5 Chronic schizophrenic patients with enhanced aggregation showed significant week to week variation in platelet aggregation response. Variability of responses was not related to the drug used or to the dose administered. There was some evidence that higher plasma concentrations of neuroleptic drugs were associated with enhanced platelet aggregation responses. 6 Treatment with neuroleptic drugs leads to enhancement of platelet aggregation responses induced by 5-HT. The frequency and reliability with which such responses can be elicited is unpredictable and the value of platelet aggregation responses as an empirical guide to treatment with neuroleptic drugs is therefore open to question.

Antipsychotic Agents↗
PubMed1981

The reliability of 5-hydroxytryptamine induced platelet aggregation responses in schizophrenic patients treated with neuroleptic drugs.

1 The reliability of 5-hydroxytryptamine induced platelet aggregation responses in psychiatric patients treated with neuroleptic drugs was investigated by examining the effects of a number of technical factors which could account for the variability of responses observed in some patients. 2 Variation in incubation time, temperature, aggregometer stirrer speed, and in the time interval between withdrawal of the blood sample and testing, had no significant effects on the consistency of responses. 3 Dilution of platelet rich plasma (PRP) led to enhanced platelet aggregation responses becoming non-enhanced. 4 Overcentrifugation of blood samples during the preparation of PRP caused a decrease in the incidence of enhanced platelet aggregation responses observed in chronic schizophrenic patients receiving chlorpromazine. 5 The reliability of platelet aggregation responses as indices of the action of neuroleptic drugs in psychiatric patients remains doubtful.

Antipsychotic Agents↗
PubMed1981

Evaluation of rosaramicin phosphate in treatment of experimental syphilis in rabbits.

The in vivo activity of rosaramicin phosphate in disseminated and localized Treponema pallidum infections in rabbits was compared with that of penicillin G benzathine. Rabbits were injected either intradermally or intravenously to establish infection. Groups of four animals each then received either two weekly injections of 200,000 U of penicillin G benzathine, injections of 12.5 or 25 mg of rosaramicin per kg of body weight twice a day for 10 days, or no antibiotic therapy. Treatment of the intradermal and intravenous infections was initiated on days 7 and 14 postinfection, respectively. With both infection models, striking differences were noted between the untreated control rabbits and the three groups receiving treatment; no discernible differences, however, were detected among any of the treated groups. Rabbits that had been infected intravenously did not develop disseminated lesions or orchitis after treatment, and chancres produced by intradermal infection regressed and healed rapidly after the initiation of therapy. Continued increases in treponemal and nontreponemal antibody titers posttreatment did not occur in any of the treated rabbits. Infectivity studies also suggested that the lymph nodes and testes of treated animals were free from infectious organisms. Overall, at the dosage regimens employed, both rosaramicin and penicillin G benzathine appeared to effect complete control of the experimental disease.

Animals↗
PubMed1981

Familial polymorphous cold eruption.

An erythematous, burning papular eruption, constitutional symptoms, fever, and arthropathy developed in a 65-year-old patient after cold exposure. Involvement of other family members occurred in an autosomal dominant pattern. Histopathologic examination of a biopsy specimen revealed telangiectasia and primarily neutrophilic perivascular inflammation, consistent with earlier biopsy reports of this syndrome. Although previously called "familial cold urticaria," this disease is not characterized by urticaria and may be best descriptively termed, "familial polymorphous cold eruption."

Aged↗
PubMed1980

Volumetric changes in cells during freezing and thawing.

A thermodynamic model is presented to describe the combined freezing and thawing process for living cells. Continuous changes in the cell volume are predicted according to the thermal protocol imposed on the system. Experimental verification of the model is sought by monitoring continuously the volume of cells as frozen on a cryomicroscope. The volumes of individual cells are measured from sequential photomicrographs by a computerized image analysis technique. The model and experimental data are in quite close agreement for the freezing process, but upon thawing the experimentally measured volumes consistently increased much more rapidly than predicted by the model. The model can be made to conform to the data by accounting for a substantial influx of electrolyte to the cell at subfreezing temperatures.

Cell Membrane↗
PubMed1980

Bacterial interference of Neisseria gonorrhoeae by alpha-haemolytic streptococci.

Fifty pharyngeal isolates of alpha-haemolytic streptococci were tested against 20 cervical isolates of Neisseria gonorrhoeae for bacterial interference in vitro using the lawn-spotting method. Forty-seven (94%) isolates of streptococci showed inhibitory activity toward N gonorrhoeae, although nine of these were inhibitory to only one isolate of N gonorrhoeae. Isolates of N gonorrhoeae varied widely in their sensitivity to streptococci; the most sensitive were inhibited by 40 isolates of streptococci and the least sensitive by only 14 isolates. Species of Streptococcus found to inhibit growth of N gonorrhoeae were S mitis, S MG intermedius, S sanguis II, S mutans, and S morbillorum.

Adult↗
PubMed1980

A study of weight reducing diets in psychiatric in-patients.

Seventy-four overweight psychiatric in-patients were treated with weight reducing diets for periods varying from 6 months to 34 months. Seventy per cent lost weight and 18 per cent attained an ideal weight. Weight reducing diets should be considered an important aspect of treatment for the majority of obese patients in psychiatric hospitals regardless of the cause of obesity.

Adult↗
PubMed1979

Group B streptococcal infection: a review and update.

The problems posed by the sudden increase in serious group B streptococcal disease among infants since the early 1970s are described and discussed. Virtually all offspring of colonised mothers harbour the organism and infection develops in about 1% of these infants. The mortality rate, even with immediate antibiotic treatment of early onset disease, is 30%; delay in treatment leads to much higher mortality. Late onset disease starting around the seventh to ninth day of life, but sometimes as late as the second month, is less frequently fatal. Preventive measures include active and passive immunisation or intravenous ampicillin during labour. Experimental evidence indicates that each of these methods gives protection.

Antibodies, Bacterial↗