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Biomedical subjects

D Campbell

Publications and source records attributed to D Campbell.

At least 271 records · Page 15Linked to original sources
PubMed1987

Achondrogenesis type II, abnormalities of extracellular matrix.

Immune and lectin histochemical and microchemical methods were employed to study growth cartilage from seven cases of achondrogenesis type II (Langer-Saldino). The normal architecture of the epiphyseal and growth plate cartilage was replaced by a morphologically heterogeneous tissue. Some areas were comprised of vascular canals surrounded by extensive fibrous tissue and enlarged cells that had the appearance and histochemical characteristics of hypertrophic chondrocytes. Other areas contained a mixture of cells ranging from small to the enlarged chondrocytes. The extracellular matrix in the latter areas was more abundant and had characteristics of both precartilage mesenchymal matrix and typical cartilage matrix; it contained types I and II collagen, cartilage proteoglycan, fibronectin, and peanut agglutinin binding glycoconjugate(s). Peptide mapping of cyanogen bromide cartilage collagen peptides revealed the presence of types I and II collagen. These observations could be explained by a defect in the biosynthesis of type II collagen or in chondrocyte differentiation.

Bone Diseases, Developmental↗
PubMed1987

Modulation of normobaric pulmonary oxygen toxicity by hydroxyl radical inhibition.

The effects of hydroxyl radical inhibition on an experimental model of normobaric pulmonary oxygen toxicity have been studied. The metal ion chelator, desferrioxamine (which inhibits hydroxyl-radical generation) or the hydroxyl-radical scavenger, dimethylthiourea (DMTU), were administered in an attempt to block hydroxyl-radical-mediated tissue injury. Lung injury was monitored in Sprague-Dawley rats by examining lung histology and bronchoalveolar lavage and by assessing pulmonary capillary permeability using the 125I-albumin lung permeability index and the lung weight:body weight ratio. Control animals had lung permeability indices 0.183 +/- 0.005 and lung weight to body weight ratio of 4.50 +/- 0.10 (all as mean +/- SEM). With increased duration of exposure to hyperoxia, there was a progressive increase in pulmonary inflammation, with thickening of alveolar membranes and atelectasis and a progressive increase in lung permeability indices (0.434 +/- 0.088 at 24 hrs; 0.954 +/- 0.165 at 48 hrs; and 1.55 +/- 0.214 at 60 hrs); and lung weight to body weight ratio (5.28 +/- 0.11 at 24 hrs; 6.54 +/- 0.23 at 48 hrs; and 8.91 +/- 0.51 at 60 hrs). Treatment with desferrioxamine provided significant protection from lung injury after 24 hrs of hyperoxia (eg., lung permeability indices 0.250 +/- 0.018; lung weight to body weight ratio 4.68 +/- 0.14, both p less than 0.025; cf. 24-hr hyperoxia controls) but no reduction in pulmonary injury was observed after 48 and 60 hrs of hyperoxia exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Halothane and the liver.

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Chemical and Drug Induced Liver Injury↗
PubMed1986

Mortality probability in victims of fire trauma: revised equation to include inhalation injury.

There are no clear guidelines on the early diagnosis of injury due to inhalation of smoke. A clinical scoring system in the form of a previously prepared questionnaire may be used in the accident and emergency department by staff who are inexperienced in the management of inhalation injury. By quantifying injury due to smoke inhalation, its contribution to mortality in a large group of fire victims was established and a revised mortality probability equation derived using age, percentage surface area of the burn, and extent of inhalation injury. This mortality probability equation may be used to divide patients into risk categories for early intensive care management and allows the comparison of mortality data between accident and emergency units receiving varying numbers of patients with injuries due to burns and smoke inhalation.

Adolescent↗
PubMed1986

Identification of the human papilloma virus-1a E4 gene products.

Antibodies prepared against a human papilloma virus-1 (HPV-1) E4/beta-galactosidase fusion protein identified several polypeptides in HPV-1, but not HPV-2 or 4, induced papillomas. The major E4 protein, that represented up to 30% of total cellular protein, was a 16/17-K doublet which was purified by column chromatography and analysed for amino acid content. A peptide derived by chymotryptic digestion was purified by h.p.l.c. and subjected to amino acid sequencing. The unique sequence obtained, Gly-His-Pro-Asp-Leu-Ser-Leu, identified the 16/17-K doublet as a product of the HPV-1 E4 gene region. Antibodies to both the E4/beta-galactosidase fusion protein and the 16/17-K doublet identified two smaller polypeptides (10/11-K) which may represent spliced products of E4. We propose that the products of the HPV-1 E4 gene region are not classical DNA tumor virus early proteins and suggest that they play a role in virus maturation.

Amino Acid Sequence↗
PubMed1986

Tumor-derived suppressor factors (TDSFs) in normal and neoplastic colon and rectum.

Acid tumor-derived suppressor factors (TDSFs, isoelectric pH less than 3.0) in extracts of murine fibrosarcomas and human colorectal adenocarcinoma cell lines induce normal murine spleen cells to inhibit delayed-type hypersensitivity (DTH) to the sensitizer dinitrochlorobenzene (DNCB). We sought to determine if TDSF from normal and neoplastic human colon and rectum also inhibited normal human peripheral blood mononuclear cells (PBMC) responses to mitogen and to alloantigens. Collagenase-DNase digests of five freshly isolated carcinomas and paired autologous normal tissues were subjected to preparative isoelectric focusing (pIEF) over a pH range of 2.5 to 9.5. Fractions with isoelectric pH less than 3.0 from three of the five tumors induced normal C3H/HeN spleen cells to inhibit DTH to DNCB. Acid fractions from three tumors and four normal tissues also significantly inhibited the PBMC proliferative response to mitogen and alloantigens. However, the ability of acid fractions to suppress lymphocyte proliferation did not correlate with the induction of suppression of DTH to DNCB. Incubation of human PBMC with acid proliferation inhibitors did not induce suppressor cells that would inhibit the subsequent proliferative response of fresh, autologous PBMC. The acid suppressant from colorectal carcinoma was sensitive to treatment with trypsin but not RNase or DNase, whereas murine TDSF is sensitive to RNase and resistant to treatment with trypsin. The suppressive moiety from one tumor had an apparent mass of 45 kDa by gel filtration chromatography, in contrast to murine TDSF that has a mass of more than 300 kDa. Thus, the acid inhibitor in digests of human colorectal carcinoma is distinct from the TDSF that induces suppressor cells for DTH to DNCB.

Animals↗
PubMed1986

An empirical typology of problem drinkers from the Michigan Alcoholism Screening Test.

In a program of treatment for persons convicted of driving while intoxicated, data from 504 male participants were collected and analyzed to identify groups homogeneous with respect to symptoms and consequences of problem drinking as indicated on the Michigan Alcoholism Screening Test (MAST). Cluster analysis of MAST responses yielded 7 such groups, differing in level and pattern of alcohol-related problems. This classification was shown: (a) to be homogeneous and reliable; (b) to discriminate effectively within several sets of external criteria--specifically, scales and profiles from the Minnesota Multiphasic Personality Inventory (MMPI) and clinical ratings of reasons for drinking and of participation and outcome from treatment; and (c) to predict alcoholism criteria more powerfully than dimensional use of the MAST. Categorical representation of alcoholism from its psychosocial symptoms was shown to be a valid and valuable structural approach.

Adult↗
PubMed1986

Randomized clinical trial of an oscillating air mattress in preterm infants: effect on apnea, growth, and development.

To investigate claims that oscillating mattresses reduce apnea of prematurity and improve growth and neurobehavioural development, we performed a randomized clinical trial using a predetermined sample size. Preterm infants weighing from 750 to 1750 gm at birth were randomly assigned, by 250 gm strata, to either a conventional mattress (n = 63) or to an air mattress (n = 59) oscillating at 14 to 16 regular pulses per minute. Infants remained on the oscillating air mattress for at least 7 days or until 34 weeks postmenstrual age. Apneic episodes occurred and required treatment equally in the two groups; this lack of an effect was seen for both sexes and all weight groups. Both weight and energy intake were similar. Neurobehavioral development as shown by sleep state, habituation testing, and behavioral assessment at term, 3, 6, and 12 months was similar in the two groups. There was no difference in the incidence of neurologic abnormalities. We conclude that an oscillating air mattress has no prophylactic value in reducing apnea and does not enhance growth and development.

Air↗
PubMed1986

Energy balance in low birth weight infants fed formula of high or low medium-chain triglyceride content.

We tested the effect on energy balance of the partial substitution of medium-chain for long-chain triglycerides in the diet of growing low birth weight infants. Fifteen infants were studied in a randomized double-blind crossover clinical trial in which each infant was fed each of two formulas, which were of equal gross energy and protein content but differed in fat composition. The high medium-chain triglyceride (MCT) formula contained medium- and long-chain triglycerides in a weight/weight ratio of 46:54; in the low MCT formula the ratio was 4:96. The hypothesis tested was that under conditions of equal gross energy intake the two diets would differ in their digestible and metabolizable energy contents and would produce differences in the infants' rates of energy expenditure and energy storage. Gross energy intakes averaged 562 and 555 kJ/kg/day (134 and 133 kcal/kg/day) with the high and low MCT formulas, respectively. With each diet, coefficients of energy digestibility (0.93) and metabolizability (0.91) were identical; the rates of energy expenditure were 262 (high MCT) and 265 (low MCT) kJ/kg/day (63 kcal/kg/day for both diets), and of energy storage were 246 (high MCT) and 239 (low MCT) kJ/kg/day (59 and 57 kcal/day). These differences were not significant. There were also no significant differences between the two diets in coefficients of nitrogen retention (mean 0.70) or in rate of weight gain (mean 21.5 gm/kg/day). The use of high MCT content in infant formula neither provided a nutritional advantage in energy digestibility or metabolizability nor resulted in an increased rate of energy expenditure or of energy storage.

Body Weight↗
PubMed1986

Effects of certain i.v. anaesthetics on liver blood flow and hepatic oxygen consumption in the greyhound.

The effects of increasing concentrations of thiopentone, Althesin and etomidate on liver blood flow and hepatic oxygen consumption were investigated in the anaesthetized greyhound. All three agents studied produced dose-related decreases in general cardiovascular indices such as mean arterial pressure, cardiac output and systemic vascular resistance; all three anaesthetics produced decreases in liver blood flow. During the low rates of infusion with Althesin and etomidate, significant decreases in hepatic arterial blood flow were recorded at a time when the systemic circulation was not significantly affected. Indeed, during the low rates of infusion with each of the three agents, hepatic arterial resistance and mesenteric vascular resistance increased by up to 40% above baseline values. During the high rates of infusion, hepatic arterial and mesenteric vascular resistances either returned to or decreased below control values and the decreases in liver blood flow were a consequence of generalized cardiovascular depression. Despite relatively unchanged hepatic oxygen consumption, all the anaesthetics produced significant decreases in the hepatic oxygen supply.

Alfaxalone Alfadolone Mixture↗
PubMed1986

Research priorities in mental health.

Setting research priorities becomes necessary when the demand for research funds outstrips the supply; because it is impossible to do everything some topics must be chosen as more promising and pertinent than others. This paper proposes a scheme for estimating the relative merits of different branches of research within the whole field of mental health. The scheme for assessing the claims of each area is based upon three factors: the need for research in a particular topic (using data about prevalence of disorders; the costs attributable to disorders; and the like); the possibilities of doing good science; the estimated time to a clinical payoff. It is argued that reasonable assessments of these three factors can be combined to give a relative weight to any particular research area. The judgements of relative weight can be progressively improved as more data becomes available. The argument is put that one way to obtain more funds for mental health research overall is to improve the ordering of the different areas within the field of mental health. Once mental health has its house in order it will be better equipped to make the case for mental health research.

Canada↗
PubMed1986

Validity of an MMPI classification of problem drinker-drivers.

An empirical typology of problem drinker-drivers based on the Minnesota Multiphasic Personality Inventory (MMPI) was evaluated. Relationships were demonstrated between this typology and several kinds of external criteria: alcoholism symptoms, reasons for drinking, treatment participation and outcome and medical complications. Indicators of typological validity were further evaluated in the context of alternative means of scoring and categorizing MMPI profiles. Relationships of criteria with the drinker-driver typology were generally stronger than with other uses of the MMPI. They were, however, weaker than those formed with an unweighted combination of three scales: Psychopathic Deviate, Depression and the K (test-taking attitude) validity scales. Results suggest that the typology divides the population of drinking drivers meaningfully and more powerfully than several, but not all, alternative uses of MMPI profiles.

Adult↗
PubMed1986

Experience with Althesin in the management of persistently raised ICP following severe head injury.

Of 243 patients who underwent intracranial pressure (ICP) monitoring after severe head injury, 42 (17%) were found to have severe persistently raised ICP, in spite of hyperventilation, mannitol, and surgical decompression. Althesin was infused to reduce ICP in these patients. This agent was shown to be effective and safe in reducing ICP, and a significant improvement in cerebral perfusion pressure was demonstrated. In this respect, Althesin may be more effective than barbiturates. However, no improvement in patient outcome was demonstrated in this series.

Adolescent↗