Biomedical subjects
C Morrison
Publications and source records attributed to C Morrison.
An NGF-inducible octamer binding protein activity in a C1300 neuroblastoma cell line.
Nerve growth factor (NGF) induces a protein in the C1300 mouse neuroblastoma cell line which recognises the octamer DNA consensus sequence 'ATGCAAAT'. This protein is absent, or only minimally present, in C1300 cells prior to induction with NGF. This induced octamer binding protein is detectable by gel retardation analysis within 3 h of NGF treatment and increases progressively with 24 h and 72 h of exposure to NGF.
The HIV epidemic. Ethical issues for the next decade.
The HIV epidemic and ethical issues will continue to be a major topic of discussion over the next decade. It is now evolving into a new phase and we are experiencing a change or shift in the populations that are affected. This article focuses on the issues of early intervention, access to care, and the continuum of care including a discussion of case management, the changing populations, drug trials, and issues surrounding confidentiality.
Effect of age, family status, and physical activity on selected dietary components of TAC pilots.
This study gathered dietary data on Tactical Air Command (TAC) pilots for descriptive and analytic purposes. One hundred eighteen TAC pilots from five bases were interviewed concerning their diet, age, family configuration, and exercise level. Dietary information was recorded using the PruCal 3-day dietary report form, while the remaining information was recorded on a personal interview form. Pilots were grouped according to age (three levels), family configuration (three levels), and exercise (three levels). The groups in each category were tested (analysis of variance) for differences in their intake of protein, carbohydrates, fat, alcohol, and caffeine, and for demographic differences. Differences between exercise groups were found for weight and carbohydrates consumed. Age group differences were seen in alcohol intake and fat consumption. Further findings suggest pilots do not have diets which meet dietary guidelines. There appears to be a need for nutrition education, dietary modification programs, and further study of the diets of TAC pilots.
Astigmatically neutral sutured small incision.
The desire for rapid visual rehabilitation following phacoemulsification for cataract and intraocular lens implantation has stimulated a quest for an "astigmatically neutral" incision. We have evaluated an underemphasized aspect of wound closure technique for a small incision wound (5.1 mm). The essential element of the technique is reinflation of the anterior chamber after a nylon shoelace suture is placed and tied once but before the knot is finally secured. The resulting changes in corneal curvature are analyzed. Results are presented at two weeks and six weeks postoperatively. We have termed this technique post-suture inflation.
Regulation of preprotachykinin gene expression by nerve growth factor.
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Syme's two-stage amputation in insulin-requiring diabetics with gangrene of the forefoot.
Thirty-five insulin-requiring adult diabetic patients underwent 38 Syme's Two-Stage amputations for gangrene of the forefoot with nonreconstructible peripheral vascular insufficiency. All had a minimum Doppler ischemic index of 0.5, serum albumin of 3.0 gm/dl, and total lymphocyte count of 1500. Thirty-one (81.6%) eventually healed and were uneventfully fit with a prosthesis. Regional anesthesia was used in all of the patients, with 22 spinal and 16 ankle block anesthetics. Twenty-seven (71%) returned to their preamputation level of ambulatory function. Six (16%) had major, and fifteen (39%) minor complications following the first stage surgery. The results of this study support the use of the Syme's Two-Stage amputation in adult diabetic patients with gangrene of the forefoot requiring amputation.
Evidence for communication between nerve growth factor and protein tyrosine phosphorylation.
Nerve growth factor (NGF) stimulation of PC12 cells activated two myelin basic protein (MBP) kinase activities greater than 10-fold within 5 min, which were resolved by chromatography on Mono Q. Each enzyme phosphorylated MBP on threonine and was inactivated by incubation with either CD45, a protein tyrosine phosphatase, or protein phosphatase 2A (PP2A), a serine/threonine phosphatase. The effects of CD45 and PP2A were prevented by vanadate and okadaic acid, respectively. Activation of the MBP-kinases provides a mechanism for communication between NGF and intracellular protein tyrosine phosphorylation.
Novel cell lines display properties of nociceptive sensory neurons.
Hybrid cell lines derived from neonatal rat dorsal root ganglia neurons fused with the mouse neuroblastoma N18Tg2 exhibit sensory neuron-like properties not displayed by the parental neuroblastoma. These properties include an inward (depolarizing) current with a conductance increase in response to activation of a bradykinin receptor, an inward (depolarizing) current with a conductance increase in response to the sensory excitotoxin capsaicin, the expression of sensory neuropeptides (substance P, CGRP and somatostatin), the expression of phosphatidylinositol-anchored molecules including adhesion molecules of the immunoglobulin superfamily that can be regulated in serum-free culture by nerve growth factor (N-CAM, F-3 and Thy-1), and low permissivity to herpes simplex virus infection. These lines thus provide appropriate models for the study of mechanisms involved in nociceptor activation and the regulation of expression of sensory-neuron specific markers including neuropeptides.
Smoking and housing status in Scottish MONICA: examples of a modified case-control analysis.
Data from the Scottish MONICA Project in North Glasgow has been used to compare the characteristics of coronary heart disease cases with those of a sample of men and women drawn from the general population. A case-control methodology was used, with cases taken from the MONICA register of acute myocardial infarction events for 1985 and 1986, and controls from the MONICA population survey conducted in 1986. Information on smoking levels and on housing status is available for both cases and controls, and this information has been used to provide examples of possible analyses. Relative risks were estimated for smoking, and it was found that current smokers had 3.8 times the level of risk of never-smokers in men and 3.1 times in women. Some evidence for a dose-response relationship was found, with heavy smokers being at higher risk. A comparison of cases and controls by housing status revealed that both men and women in public housing are at higher risk than home owners, but that some of this increased risk is related to the higher smoking levels of council housing tenants. These analyses can be extended to other factors provided information is available on both coronary cases and survey subjects.
Spectrophotometric determination of the critical micellar concentration of bile salts using bilirubin monoglucuronide as a micellar probe. Utility of derivative spectroscopy.
We have developed a simple biologically non-invasive method for determining the critical micellar concentration (CMC) of bile salts using pure naturally occurring bilirubin IX alpha monoglucuronide (BMG), an important bile pigment present in virtually all mammalian biles. This methodology employs visible absorbance spectroscopy of BMG in bile salts over a range of bile salt concentrations that include the reported CMC. Using 100 microM-BMG in 0.4 M-imidazole buffer at pH 7.8, we calculated that the CMC for sodium taurochenodeoxycholate is between 2.5 and 3.0 mM based on: (1) an abrupt change in lambda max. in this concentration range, (2) a precipitous decrease in the amplitude of the absorbance shoulder at 450 nm, (3) a sudden decrease in the second derivative absorbance of BMG at 400 nm and an increase in absorbance at 470 nm, (4) a sharp change in the 4th derivative absorbance at 375 and 395 nm. In contrast, sodium taurocholate, a bile salt that reportedly does not have a CMC but continuously self-associates over a wide concentration range, exhibited none of these changes. The use of derivative spectroscopy enhances the ability to detect the CMC changes and also indicates the number of BMG species in solution and their relative energy states.
An investigation of the fracture characteristics of the tibia of mature rabbits.
The therapeutic implications of the physical aspects of fractures have not yet been clearly defined. We have studied the fracture characteristics of the tibia of mature male rabbits by producing fractures manually and mechanically. The fractures were studied by radiology, by recording fracture strains graphically and by direct measurement of the magnitude of the fracture force. The fracture behaviour of the mature rabbit tibia was found to be similar to that of adult human bone in that they were brittle and fractured in the tension mode without plastic deformation. Angulatory forces were observed to produce transverse and oblique fractures and spiral forces produced spiral fractures in all cases. The maximum bending moment before fracture was 4000 Nmm, the maximum shear moment was 1870 Nmm and the mean of the maximum tensile stress in each case was 20 N/mm2. It was concluded from this that fractures produced by angulatory forces caused the greater damage to the surrounding soft tissues compared with spiral fractures.
Effects of HIV antibody test knowledge on subsequent sexual behaviors in a cohort of homosexually active men.
This study assesses the effects of HIV (human immunodeficiency virus) antibody testing on subsequent (one year) sexual behavior among 270 homosexual men at a Boston community health center, 21 per cent of whom were unaware of their test result. Except for the number of steady partners, the levels of all sexual activities of all groups of study participants declined over time. No effects of test awareness of antibody status were found on protective behavior for receptive anogenital contact. Elimination of unprotected insertive anogenital contact (by elimination of the practice or by condom use) was reported somewhat more often among seropositive men who became aware of their test result. Increased negative emotional reactions were reported by HIV seropositive men who were aware of their test result. These results suggest some behavioral impact of HIV antibody test knowledge in this cohort, but may not be generalizable to other populations.
Scale development in talpid3 mutant chick embryos.
The fact that dermal condensations are not, as they are in feather development, involved in early scale morphogenesis in birds suggests that in the mutant talpid3, where mesenchymal cell surface and motility properties are impaired, scales might develop relatively normally though feathers do not. This prediction has been checked using chorioallantoic membrane grafts of talpid and normal hind limbs, and found to be substantially justified although the abnormal overall shape of the talpid limb has a distorting effect on scale patterning. However, the abnormal talpid dermis seems to have effects on the direction and extent of epidermal invagination at scale margins. Since the control of epidermal invagination is a relatively unexplored area, this is a particularly useful finding.
Outbreak of neonatal Citrobacter diversus meningitis in a suburban hospital.
Between February and June, 1983, four cases of Citrobacter diversus neonatal meningitis were identified at a suburban Baltimore hospital. One of the 4 infants died at age 13 months, 2 (both of whom had brain abscesses) have evidence of developmental delay and 1 appears to be normal after 33 months of follow-up. A review of microbiology records revealed that C. diversus had been present in the hospital nursery prior to identification of the first infant with meningitis, with isolation from infants born 7 months, 4 months and 4 days, respectively, before the first meningitis case. C. diversus was isolated from 21 infants born during the outbreak period and from hand or rectal cultures of 5 nursing personnel. All isolates were biotype E, with two distinct clusters of cases identified on the basis of plasmid profile and serotype. In a case-control study isolation of C. diversus was significantly associated with male sex, low birth weight and care by house pediatricians. The outbreak was controlled by stringent infection control measures and exclusion of personnel carriers. During the 24 months following the outbreak 3431 babies discharged from the nursery were cultured for C. diversus; 3 were colonized with the organism.
AIDS "Train the Trainer" program underway.
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Persistence of cholera in the United States: isolation of Vibrio cholerae O1 from a patient with diarrhea in Maryland.
A case of cholera was identified in Baltimore County, Md., in October 1984. The Vibrio cholerae O1 isolate from the patient was hemolytic, biotype El Tor, serotype Inaba, and was toxigenic by the Y-1 adrenal cell assay; on Southern blot analysis, the strain had a unique HindIII restriction site in the cholera toxin gene identical to that of other U.S. V. cholerae O1 isolates. Two days before he became ill, the patient had eaten meat from crabs harvested along the Texas coast.
Effect of instructional units on the analysis of related and unrelated skills.
84 majors in elementary education were divided into three groups, one control group and two experimental groups. The control group received no instruction in skill analysis while the experimental groups were instructed via videotape in either the instep kick in soccer or in throwing, catching, and striking skills. All three groups were given a skill-analysis test composed of throwing, catching, and striking skills. Statistical analysis yielded significant effect for those who viewed the throwing, catching, and striking videotape. No effect was found for the control group or the group who viewed the soccer-instep videotape. The results suggest specificity may be as important in skill analysis as in acquisition.