Biomedical subjects
Publications and source records attributed to J C Hall.
Resident mouse peritoneal macrophages contain a phospholipase C of high activity that is specific for phosphatidylinositol. The activity has a neutral pH optimum, is Ca(2+)-dependent and has a maximum reaction velocity of 525nmol/h per mg of protein. Certain phenothiazines are potent inhibitors of this activity.
A review of 1,007 patients treated a spinal injuries unit revealed 11 instances of rupture of the diaphragm. In five patients it took more than 48 hours before the ruptured diaphragm was diagnosed. The hazards of delay in diagnosis and treatment were highlighted by three instances of gastric perforation--two due to attempted pleural aspiration and one spontaneous. There is a need for the greater use of contrast radiology in the assessment of these patients.
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Lesions indistinguishable from coumarin necrosis developed in three patients who were given heparin sodium subcutaneously. Two of the patients had received only heparin while another had also received coumarin. Heparin necrosis should be added to the list of complications of anticoagulation therapy.
Mutations that eliminate acetylcholinesterase (AChE) activity were used to study the effects of disrupted acetylcholine metabolism on the form and function of the central nervous system in Drosophila melanogaster. Mutants in the Ace gene, which have no AChE activity, usually die in early development, but the postembryonic effects of this lesion can be studied in genetic mosaics, or with conditional mutants. Adult mosaics, which expressed Ace mutations in part of their CNS, exhibited morphological defects in any ganglionic neuropile whose cells were mutant. The defects included reduction in ganglionic volume, a condensed appearance, and for a very large clone, degeneration. Examination of many such mosaics indicated that small clones restricted to one side of the CNS were not usually lethal. However, mosaics with large clones, with clones on either side of the posterior slope of the protocerebrum, or with clones encompassing symmetrical structures on both sides of the CNS rarely survived to adulthood. Mosaics with AChE-null tissue on either side of the optic lobes or the posterior-inferior protocerebrum had marked deficits in optomotor behavior, although they were outwardly normal in their movement and posture. Mosaics with Ace mutant tissue in the first-order optic lobe, the lamina, lacked a synaptic component of the electroretinogram, the "off" transient. Tests of courtship behavior revealed that AChE mosaics with mutant clones in the superior protocerebrum were often capable of demonstrating male courtship. However, their behavior was quantitatively and perhaps qualitatively deficient. In order to study critical periods for the effects of mutant AChE, temperature-sensitive mutations of the Ace gene were isolated. Flies bearing certain of these new mutations produced AchE activity that was thermolabile in vivo and in vitro. The critical period during which the mutants were most susceptible to conditional lethality was late in embryogenesis.
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Courtship song in Drosophila is produced by the male's wing vibration and consists of pulses of tone produced at intervals of approximately 34 msec in D. melanogaster and 48 msec in D. simulans. We have observed that the intervals between these pulses are not constant but fluctuate rhythmically with periods of approximately 1 min in D. melanogaster and 0.5 min in D. simulans. In D. melanogaster, three allelic per mutations have been isolated which affect the periodicity of the circadian oscillators affecting both eclosion and locomotor activity [Konopka, R. & Benzer S. (1971) Proc. Natl. Acad. Sci. USA 68, 2112-2116]. Each of the per alleles--pers, which shortens the circadian period, perI, which lengthens it, and perO, which abolishes it--strikingly affects the 60-sec song rhythm in a parallel fashion. Therefore, both circadian rhythms and a very short, noncircadian oscillation appear to be influenced by the same gene.
If a test involves subjective evaluation then different observers will record different findings. This is true of upper limb anthropometry. Unless the interobserver measurement variation is quantified then the detection of real, rather than apparent, measurement changes is hindered. This paper uses a new statistical approach to interpret apparent measurement changes in the presence of observer variation.
Temperature-sensitive (ts) mutants of the Ace gene, which codes for acetylcholinesterase (AChE) in Drosophila melanogaster, were analyzed for defects in viability, behavior and function of the enzyme. The use of heat-sensitive and cold-sensitive mutations permitted the function of AChE in the nervous system to be analyzed temporally. All ts mutations were lethal, or nearly so, when animals expressing them were subjected to restrictive temperatures during late embryonic and very early larval stages. Heat treatments to Ace-ts mid- and late larvae had little effect on the behavior of these animals or on the viability or behavior of the eventual adults. Heat-sensitive mutants exposed to nonpermissive temperatures as pupae, by contrast, had severe defects in phototaxis and locomotor activity as adults. AChE extracted from adult ts mutants that had developed at a permissive temperature were abnormally heat labile, and they had reduced substrate affinity when assayed at restrictive temperatures. However, enzyme activity did not decline during exposure of heat-sensitive adults to high temperatures even though such treatments caused decrements in phototaxis (29 degrees) and, eventually, cessation of movement (31 degrees). The cold-sensitive mutant also produced readily detectable levels of AChE when exposed to a restrictive temperature during the early developmental stage when this mutation causes almost complete lethality. We suggest that the relationship among the genetic, biochemical and neurobiological defects in these mutants may involve more than merely temperature-sensitive catalytic functions.
Daily protein and calorie intake, three plasma protein estimations, two upper limb anthropometric measurements, and estimated weight loss were all determined in 31 patients attending a surgical oncology outpatient department. The patients, who had had prior resection of a gastrointestinal cancer, could be divided into three groups depending on (i) the absence of clinically detectable tumour; (ii) the presence of clinically detectable tumour with survival over the ensuing four-month period; and (iii) clinically detectable tumour without survival over the ensuing four-month period. The variables least able to discriminate between these groups, and to interrelate to the other variable in a cross-correlation matrix, were the dietary intake data and the estimated weight loss. It is concluded that protein-calorie malnutrition can be adequately assessed in patients with advanced cancer from studies of the plasma albumin, prealbumin, transferrin, arm fat area, and arm muscle area.
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Brain abscess is an uncommon complication of the insertion of skull tongs. The two cases reported demonstrate the difficulty that may occur in diagnosis and the high mortality associated with this complication.
Male courtship behaviour in Drosophila melanogaster is modified by prior sexual experience. Whereas naive males nearly always court virgin females persistently, males previously paired with unreceptive fertilized females subsequently court virgin females in an abbreviated manner, if at all. The probability of diminished male courtship is directly related to the duration of the prior "conditioning" period with a fertilized female. Naive males court fertilized females less vigorously than they court virgins; this depression of male behavior occurs even if the male is blind or if the fertilized female cannot actively reject his courtship. These results suggest that fertilized females are a source of both courtship-provoking and courtship-inhibiting olfactory cues and that the central association of these cues in males is sufficient to bring about the retention of modified courtship behavior. Mutant "amnesiac" males, selected as memory-deficient in a learning test unrelated to courtship [Quinn, W. G., Sziber, P. P. & Booker, R. (1979) Nature (London) 277, 212-214], are trainable by exposure to fertilized females, but the experience-dependent behavior-diminished courtship performance-wanes abnormally rapidly-i.e., less than 1 hour, compared to 2-3 hr for wild-type flies.
In gynandromorphs of Drosophila, a detailed examination was made of the association between male courtship behavior and the chromosomal genotype of various parts of the central nervous system. Mosaic flies that behave as males repeatedly show a shorter courtship than normal males. If there is to be male behavior, the posterior dorsal brain must be haplo-X on at least one side for occurrence of the early courtship events. Tapping, following of females and wing extension. Licking (proboscis extension) has nearly the same focus but is submissive; that is, male tissue must be present in both left and right dorsal brain. The next courtship step, attempted copulation, has a focus (especially for actual genital contact) located in the thoracic ganglia, though apparently not in a discrete region. Attempted copulation, which can occur even in mosaics with a gravid abdomen, may be correlated with the presence of sex combs. The role of courtship foci are interpreted in terms of known sensory inputs to and functions of the major insect ganglia.
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This review examines the contributions made by anorexia, loss of taste, malabsorption and disturbances of intermediary metabolism to the cachexia of cancer. Methods of nutritional assessment are outlined and mention is made of the usefulness of nutritional support as an adjunct to anti-cancer therapies.
Three cases of pseudofolliculitis are described in black American women, bringing the total number of cases described in the literature to five. Pseudofolliculitis pubis, pseudofolliculitis axillae, and pseudofolliculitis faciale (for women with facial involvement) are new diagnoses we propose to add to the nomenclature. Topical retinoic acid may be the treatment of choice. It appears that this is not a rare disease in black women.
This paper reviews the medical records of 100 consecutive patients with tetraplegia owing to diving injury. Their high survival characteristics, plus youth on presentation, create the problem of an expanding population of chronically disabled patients.