Daedalus. Encapsulated breath.
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Biomedical subjects
Publications and source records attributed to D Jones.
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Malignant hyperthermia (MH) is a genetic syndrome usually initiated by exposure to volatile anesthetic agents or depolarizing neuromuscular blocking agents. We have used Ca2+-selective microelectrodes to measure in vivo the intracellular ionized calcium ([Ca2+]i) in skeletal muscle fibers of MH-susceptible swines before and during hyperthermic episodes and also after dantrolene administration. The animals were anesthetized with thiopental and fentanyl and maintained with a mixture of nitrous oxide (66%) and oxygen (34%). The malignant hyperthermic episode was triggered by exposure to halothane. Determinations of [Ca2+]i during the episode show an increase from 0.44 +/- 0.01 microM +/- SEM, n = 20) to 8.44 +/- 0.68 microM (mean +/- SEM, n = 10). Administration of dantrolene (2 mg/kg) during the hyperthermic episode reduces [Ca2+]i to 0.17 + 0.01 microM (mean +/- SEM, n = 10) and reverses the clinical symptoms. These results show that the MH episode is associated with an increase in the myoplasmic free Ca2+ concentration and that the therapeutic effect of dantrolene is related to a decrease in [Ca2+]i.
The Genetic Diseases Program of the Illinois Department of Public Health has completed the requirements for automation of its newborn screening follow-up services. The integration of two databases containing laboratory and follow-up elements allows the system to: (1) process on-line information about both normal and abnormal results on every baby screened in Illinois, (2) recall data previously entered and add follow-up criteria, (3) generate form letters, (4) track treatment and developmental progress of confirmed clients, (5) maintain permanent demographic registries, (6) transfer records to microfiche, and (7) generate reports for statistical analysis. The intent of this paper is to describe each of the above capabilities and demonstrate how automation has enhanced the follow-up component of newborn screening.
Rift Valley fever (RVF) is a major cause of human morbidity and mortality in endemic areas of sub-Saharan Africa and has the potential to cause epidemic disease in receptive areas world-wide. In this study, a RVF viral isolate from the 1977 Egyptian epidemic (ZH-501) inoculated intravenously into rhesus macaques caused a benign viremic infection in most, but resulted in the hemorrhagic fever syndrome in 20 per cent (3 of 15). Serious disease of this type has not previously been observed in nonhuman primates inoculated with RVF virus and may be a consequence of the viral strain used or the route of inoculation. Severe disease was accompanied by extensive liver necrosis, disseminated intravascular coagulation, and microangiopathic hemolytic anemia. We also attempted to prevent RVF by passive transfer of serum from vaccinated rhesus monkeys (plaque-reduction neutralization test titer 1:2,560). As little as 0.025 ml/kg prevented the development of viremia in naive rhesus monkeys after subcutaneous inoculation of virus. The monkey model should be helpful in understanding the pathogenesis and prevention of human RVF.
The genus Listeria, containing the species Listeria monocytogenes, Listeria innocua, Listeria seeligeri, Listeria welshimeri, Listeria ivanovii, Listeria grayi and Listeria murrayi is a well circumscribed taxon. Numerical taxonomic and chemical studies indicate a very close phenetic similarity to the genus Brochothrix and a more distant, but close, similarity to a number of other genera such as Lactobacillus, Streptococcus, Lactococcus, Enterococcus, Staphylococcus, Kurthia and Bacillus. Recent 16S rRNA oligonucleotide studies have not only confirmed this relatedness but have provided information that has allowed the construction of a tentative phylogenetic classification of these taxa. On this classification the genus Listeria is very close to Brochothrix and both genera occupy a position between Lactobacillus and Bacillus.
A new micropositioner design for use in chronic, transdural single unit recording studies is presented. The adapter is used to position an electrode microdrive assembly to any desired location within a surgically implanted recording chamber. The adapter uses a radial positioning technique that requires few moving parts. In comparison with the X-Y slide manipulator it replaces, it is more durable, it provides access to a larger brain area, and it attaches more securely. In addition, provision can be made to mount a second microdrive, permitting two electrodes to be manipulated independently.
Radical changes in the technology applied to prosthetics and orthotics are being proposed. This paper attempts to define the scope and character of advanced manufacturing technology and examines the rehabilitation problems which are or could be tackled. Lower-limb prosthetics has been the major area under investigation so far, but orthopaedic footwear, spinal orthotics and custom seating for the disabled have also been investigated using similar technological approaches. The whole process of patient measurement, device design, and component manufacture is conceived as an integrated system relying upon shape or tissue property sensing, computer based device design and computer-numerically-controlled or robot manufacturing processes. The aim is to retain flexibility for custom design which is necessary to provide for individual patients, and yet improve the rapidity and precision of overall device manufacture and service delivery.
Computer aided design systems are finding use in prosthetics and orthotics in the production of customized components to match to and support body segments. Such systems consist essentially at present of shape measurement, computer manipulation of shape, and manufacture of the support surface or its mould. General themes of design philosophy, relationship of shape and pressure for body segments, representation and presentation of shape information by computer, surface adjustments, measurements and manufacturing geometry are considered. Aspects of existing systems are presented to highlight issues which may be the subject of future developments.
Patients with clinical stage B2 or C prostatic carcinoma represent a group for which there are several treatment options. We followed the course and outcome of 72 patients with clinical stages B and C prostate cancer who were treated with surgical staging, insertion of gold grains and external radiation at our institutions between 1975 and 1984. Of the patients 44 (61 per cent) had clinical stage B disease and the majority (89 per cent) of these were stage B2 lesions. The remaining 28 patients (39 per cent) had clinical stage C tumors. In our series 27 per cent of the clinical stage B and 68 per cent of the clinical stage C cancer patients had positive lymph nodes. The 5-year survival free of disease was 52 per cent for patients with both stages of disease. The 7-year survival free of disease was 47 per cent for patients with clinical stage B and 14 per cent for those with clinical stage C cancer. Lymph node status did not have a statistically significant effect on total survival but survival free of disease correlated significantly with node status. Local treatment failures were defined as patients who required transurethral prostatic resection or orchiectomy for palliation of obstructive symptoms related to local tumor regrowth. By these criteria we prevented local progression in 78 per cent of the patients at 5 years.
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One hundred and eighty-seven strains of listeriae, atypical lactobacilli, Brochothrix, Erysipelothrix and related Gram-positive bacteria were tested for 140 characters based on morphology, physiology and biochemistry. Computer analyses of the data resulted in the recovery of 20 phenons. Representative strains were examined for cytochrome content, cell wall, fatty acid and isoprenoid quinone composition and the G + C content of the DNA. The results indicate that the species Listeria monocytogenes, L. innocua and L. ivanovii are phenotypically very similar. L. grayi and L. murrayi are more distinct from these but are so similar to each other that L. murrayi should be regarded as a subspecies of L. grayi. Some of the atypical lactobacilli studied are members of the genus Brochothrix; the others probably represent four distinct species in a new genus.
Inadequate nutrition is a major problem facing the elderly today. Despite seemingly appropriate meal standards and dietary supervision, patients in long-term care facilities remain at risk for developing malnutrition. Various nutritional parameters including weight loss, percentage average body weight, serum albumin levels, anthropometrics, and skin testing were examined in 130 patients in an academic nursing home, two thirds of whom were over the age of 65 years. Functional status including type of feeding and associated diseases was also determined. The data show that nutritional risk factors are similar among different age-groups in nursing home patients. A significant proportion of our patients lost weight while maintaining their serum albumin levels. Despite this, there appears to be less evidence of malnutrition among patients in the academic nursing home compared with other nursing home settings studied.
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The authors collected data concerning assaults, assaultive patients, and victims in a psychiatric unit during a 12-month period and compared them with data from a control group of patients. Thirty-seven assaults by 25 patients were recorded. Fourteen of the victims were patients and 23 were members of staff. The assaultive group contained a significantly higher proportion of schizophrenic patients than did the control group and significantly larger numbers of patients from lower socioeconomic classes, patients admitted involuntarily under a section of the Mental Health Act, and patients with a history of assaults.
One hundred and twenty-nine (97 M, 32 F) previously untreated non-insulin-dependent diabetic patients were studied. Meal and glucose (75 g) tolerance tests were performed on two separate days with glucose, C-peptide and insulin levels estimated during each with the inclusion of growth hormone during the meal test. In addition glycosylated haemoglobin (HbA1) and plasma creatinine levels were determined. Clinical evaluation included detailed ophthalmological examination following mydriasis. Differences between retinopaths (n = 21) and non-retinopaths (n = 108) were FPG 13.7 vs 11.6 (mmol/l) (p less than 0.01); HbA1: 12.9 vs 11.3 (%) (p less than 0.01); BMI: 25.2 vs 29.4 (kg/m2) (p less than 0.001); age 56.8 vs 52.4 (yr) (ns); creatinine: 91.2 vs 88.4 (mumol/l) (ns); systolic blood pressure: 152.4 vs 143.9 mmHg (ns); diastolic blood pressure 87.9 vs 87.7 mmHg (ns); fasting growth hormone: 4.6 +/- 0.9 vs 2.4 +/- 0.3 (mU/1) (p less than 0.01). Multivariate logistic analysis however revealed that systolic blood pressure in conjunction with the insulin response gave the most significant correlation with retinopathy. No significant correlation was observed with age, sex, diastolic blood pressure, creatinine, family history or smoking. The effect of disease duration could not be evaluated. B-cell function appears central to microvascular complications in non-insulin dependent diabetes mellitus.
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The two major electrophoretic forms (pI 5.5, 5.3) of juvenile hormone esterase were independently isolated from hemolymph of larval Trichoplusia ni. A simple and rapid preparation procedure of poly(ethylene glycol) precipitation, Sephadex gel filtration and chromatofocusing is described. Analytical isoelectric focusing showed only one peak of juvenile hormone esterase activity in the respective purified samples, whereas there were four (two major) such peaks in the hemolymph. The amino acid composition of the two forms was similar. The comparison of peptides obtained after protein fragmentation by cyanogen bromide showed that juvenile hormone esterases A and B were very similar, although definitely not identical, in amino acid sequence. The immunological comparisons of juvenile hormone esterases suggested that the number of polyclonal antibody binding sites on both forms was the same. There were no detected differences between immunoreactive properties of juvenile hormone esterase from the hemolymph of different stages of larval maturation. The influence of the active site of the enzyme on its antigenic properties was studied by immunocompetition. The inactive, heat-denatured juvenile hormone esterase can only partially protect against inhibition of its activity by the antibodies, whereas an organophosphate inhibitor which covalently binds to the catalytic center of the enzyme did not change the immunoreactive properties in comparison to active juvenile hormone esterase from hemolymph. These data show that heat-denatured juvenile hormone esterase has lost at least one or more epitopes, but the catalytic site of the enzyme is distinct from the epitopes.
A number of basic metamorphosis-associated proteins were identified from several noctuid species. All of these proteins have molecular weights in the range of 73,000 to 74,000. Two of the proteins in Trichoplusia ni and Heliothis virescens were found to be suppressible by a juvenile hormone analog.