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Biomedical subjects

M Norman

Publications and source records attributed to M Norman.

At least 91 records · Page 5Linked to original sources
PubMed1991

Acute confusion--an unusual form of cerebral herpes simplex virus infection?

Herpes simplex virus (HSV) infections are common and, if afflicting the central nervous system, may cause death or severe sequelae. Since specific therapy is now available there is an increasing demand for the recognition of the various ways in which cerebral HSV-infections may be manifested. This report describes a 15-year-old boy who presented acutely with mental symptoms of confusion, hallucinations and sleep disturbance. Simultaneously, but without any increase in cerebrospinal fluid cell or protein content, an intrathecal production of HSV-antibodies of transient nature was detected. These findings suggest that the patient may have suffered from an unusual form of herpes infection in the central nervous system. We suggest that similar cases should be thoroughly explored for possible herpes etiology as early as possible during the acute phase of the disease.

Adolescent↗
PubMed1990

Blood lead, calcium status, and behavior in preschool children.

To determine if calcium status is associated with blood lead levels and behavior, 64 black urban children aged 18 to 47 months were studied. Twenty-seven controls (blood lead levels, less than 1.45 mumol/L) were compared with 37 cases (blood lead levels, greater than or equal to 1.45 mumol/L) with respect to four calcium measures (calcium intake, serum calcium level, 1,25-dihydroxyvitamin D level, and bone densitometric findings) and three behavioral scores. Levels of 25-hydroxyvitamin D provided a measure of vitamin D sufficiency. As expected, blood lead level was associated with pica scores. However, none of the calcium measures differed between cases and controls. Controlling for four confounders (season, pica score, maternal education, and sex), yielded no significant differences between the two groups in the mean values of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D level. There was no interaction between blood lead level and the four covariates. No relationship could be demonstrated between calcium status and the pica scores.

Bone Density↗
PubMed1990

Antigenic stability of fimbriae of Bacteroides nodosus.

Successful vaccination of sheep against footrot and attempts to eradicate the disease depend on there being a limit to the antigenic diversity of the causative bacterium, Bacteroides nodosus. Fimbrial antigenic variation was therefore investigated in vivo, both under conditions of chronic infection and under the pressure of a vaccine-induced immune response, to ascertain whether this represented an obstacle to such goals. Material was available from 5 experiments and although B. nodosus appeared to have undergone changes in its fimbrial antigens in one of these, the possibility that superinfection was responsible for the variation detected could not be ruled out because all sheep in this case were maintained at pasture. Overall, the results provided no evidence of fimbrial antigenic shift in B. nodosus in vivo and in conclusion, the survival of the organism in the sheep's foot, both in long-term natural infection and following vaccination, must therefore be related to factors other than the ability to undergo antigenic variation in order to evade the host's immune response.

Animals↗
PubMed1990

The proportion of glycosylated prolactin in serum is decreased in hyperprolactinemic states.

The proportion of serum PRL that is glycosylated has been determined, and the effects of physiological and pathological hyperprolactinaemia on this proportion have been examined. Glycosylated and nonglycosylated PRL were immunoprecipitated from serum and subjected to polyacrylamide gel electrophoresis under reducing and dissociating conditions. Separated proteins were then transferred to nitrocellulose paper by electroblotting and detected immunologically with anti-PRL antiserum and 125I-labeled protein-A, followed by autoradiography. The proportion of total monomeric PRL present in the glycosylated form was then estimated by densitometric scanning of autoradiograms. In normal individuals glycosylated PRL was predominant, accounting for about 72% of the circulating monomeric PRL. This proportion was markedly decreased (ranging from undetectable to about 60%) in the serum of women who were pregnant or were lactating postpartum and also in patients with hyperprolactinemia caused by a pituitary tumor. The results suggest that under basal conditions the majority of PRL secreted from the pituitary is glycosylated, but with physiological or pathological hyperprolactinemia the capacity for glycosylation is exceeded.

Adult↗
PubMed1989

A comparison between the composition of maternal peripheral plasma and plasma collected from the retroplacental compartment at caesarean section. A study on protein and steroid hormones and binding proteins.

In the pregnant uterus unique immunological conditions must prevail. Since compounds of possible fetoplacental origin may modulate the local maternal immunological response, higher concentrations of such compounds in the vicinity of the conceptus might be expected. We have measured the concentrations of several compounds in peripheral and retroplacental plasma, mainly by immunological methods, from women delivered by caesarean section in pregnancy week 38-40. Significantly higher (P less than 0.001) retroplacental concentrations were found for human placental lactogen, prolactin, alpha-fetoprotein, tissue polypeptide antigen, non-conjugated estriol and progesterone. Peripheral plasma levels were significantly higher for cortisol (P less than 0.01), transcortin (P less than 0.001) and sex-hormone binding globulin (P less than 0.002). No difference was found for albumin, alpha 2-macroglobulin, estradiol, placental alkaline phosphatase and human chorionic gonadotrophin. Significant correlations between retroplacental and maternal peripheral plasma levels were found for progesterone, cortisol, estradiol, estriol, transcortin, sex-hormone binding globulin, prolactin, human placental lactogen, human chorionic gonadotrophin, placental alkaline phosphatase, albumin and alpha 2-macroglobulin. There were also significant correlations between estradiol and sex-hormone binding globulin as well as transcortin in peripheral maternal plasma.

Adult↗
PubMed1988

Capillary blood cell velocity in full-term infants as determined in skin by videophotometric microscopy.

In order to study the neonatal microcirculation, the capillary hemodynamics in skin was investigated in 43 full-term infants 2-7 days after birth. The nailfold capillaries of the thumb were visualized by means of television microscopy and the capillary blood cell velocity (CBV) was videophotometrically quantified in 107 microvessels. The skin temperature, mean arterial blood pressure, and heel puncture hematocrit were measured simultaneously to evaluate any relation with the CBV. The mean CBV in all infants was 0.38 +/- 0.21 mm/s, with a range of 0.04 to 1.2 mm/s in individual capillaries. There was no correlation between CBV and skin temperature (27-33 degrees C), mean arterial blood pressure (44-68 mm Hg), or postnatal age. However, a significant correlation was found between the log CBV and the skin prick hematocrit (r = -0.64, p less than 0.001). It is concluded that the mean CBV during the 1st wk of life is not significantly different from the capillary velocity reported in adults. Normal variations in skin temperature and mean arterial blood pressure, as well as age differences 2-7 days after birth, do not significantly influence the neonatal skin capillary blood flow. However, the hematocrit is of major importance for skin capillary perfusion in the newborn infant.

Blood Flow Velocity↗
PubMed1988

Bioactivity and immunoactivity of growth hormone during dynamic testing of patients with acromegaly.

We have used the Nb2 cell proliferation bioassay for lactogenic hormones to investigate the biological activity of hGH in sera of patients with acromegaly. The specificity of the assay has been improved by the use of monoclonal antibodies to block the activity of individual lactogenic hormones. Disease activity in patients was assessed by scoring signs and symptoms, and by measuring IGF-I concentrations in some patients. Patients with a wide spectrum of disease activity were studied using a TRH test. hGH concentrations were measured by bioassay, RIA and immunoradiometric assay (IRMA) at 0, 20 and 60 min after injection of TRH. There was a high degree of correlation between log10 of all hGH concentrations measured by bioassay and RIA (r = 0.995, P less than 0.0001), between bioassay and IRMA (r = 0.990, P less than 0.0001), and between RIA and IRMA (r = 0.995, P less than 0.0001). In contrast to previous reports, we found no evidence for changes in the bioactivity of hGH secreted after pituitary stimulation.

Acromegaly↗
PubMed1987

Prenatal diagnosis of alpha-1-antitrypsin deficiency by fetal blood sampling.

Fetal blood sampling for the diagnosis of alpha-1-antitrypsin deficiency using protein isoelectric focusing was carried out in the period 1980-1985. The results of 25 cases from 18 mothers are reported. All had a previous history of a PiZ child affected by liver disease. The method was found to be technically satisfactory and the fetal results were subsequently confirmed in all 18 cases where follow-up was possible. The fetus was found to be PiZ in nine cases and all these pregnancies were terminated. Of the remaining pregnancies three cases aborted or were delivered prematurely and 13 proceeded to term without complications.

Adult↗
PubMed1987

Protection of sheep against footrot with a recombinant DNA-based fimbrial vaccine.

Recombinant Pseudomonas aeruginosa cells containing the Bacteroides nodosus fimbrial subunit gene under the transcriptional control of a strong promoter produce large amounts of B. nodosus-type fimbriae. We have carried out vaccination trials which show that these fimbriae are just as effective as either natural fimbriae or whole cell preparations of B. nodosus in inducing protective immunity against homologous footrot challenge. The recombinant-produced fimbriae are also effective therapeutically in accelerating the rate of healing of pre-existing footrot lesions. These results confirm that the structural subunit of the fimbrial strand is a primary protective antigen against footrot, and demonstrate the practicality and potential of recombinant DNA approaches to the development of new vaccines against B. nodosus and other Type 4 fimbriate pathogens.

Animals↗
PubMed1987

Vincristine neuropathy and a Guillain-Barré syndrome: a case with acute lymphatic leukemia and quadriparesis.

A 3 1/2-yr-old boy with acute leukemia rapidly developed quadriparesis during induction treatment that included vincristine. Accompanying the paralysis, spinal fluid protein was increased. This has not previously been associated with vincristine neuropathy. In addition to leukemia, we suggest that the patient had the Guillain-Barré syndrome, potentiating the neurotoxicity of vincristine.

Cerebrospinal Fluid Proteins↗
PubMed1987

The production and use of monoclonal antibodies to measure apolipoprotein B by a competitive enzyme-linked immunoassay.

The production of monoclonal antibodies to human lipoproteins is described. One of these antibodies, which was shown to be specific to apolipoprotein B, was used to develop a competitive enzyme-linked immunoassay for apolipoprotein B in serum samples. The antibody selected recognises apolipoprotein B in both low density and very low density lipoprotein particles, but there is no cross-reactivity with high density lipoprotein. There is no requirement for labelling of antigen or antibody used in the assay, and results obtained correlate well (r = 0.88) with measurements on serum samples using a radial immunodiffusion assay for apolipoprotein B.

Animals↗
PubMed1987

Postpartum anuria caused by silent bilateral nephrolithiasis.

A case of remarkable silent anuria caused by bilateral nephrolithiasis in the post-partum period is reported. The anuria was not associated with any kind of pain and the diagnosis was not revealed until three days postpartum when an intravenous pyelography was carried out. Differential diagnosis and management of nephrolithiasis are discussed. Ultrasound scanning is recommended as a routine procedure for all patients with signs and symptoms of renal dysfunction during pregnancy.

Adult↗
PubMed1986

The double mask--a new local scavenging system for anaesthetic gases and volatile agents.

The double mask, a new concept for local scavenging of anaesthetic gases escaping around face masks and from endotracheal tubes, is described. The system consists of a flexible silicone mask into which the anaesthetic gas mixture is led through a flow distributor which is necessary for adequate scavenging. A rigid transparent polysulphone shell surrounds the inner mask, and escaping gas is evacuated via the 3-4 mm slot between the two masks by a fan, centrally located outside the operating-room. With this system, the anaesthetist's exposure to nitrous oxide during mask anaesthesia was reduced from 145 +/- 29 to 15 +/- 3 ppm (mean +/- s.e. mean, P less than 0.001) and to halothane from 2.9 +/- 1.1 to 0.5 +/- 0.1 ppm (mean +/- s.e. mean, P less than 0.05), as measured in 32 patients aged 1-74 years. The double-mask system provided safe and adequate mask anaesthesia, as judged from inspired concentrations of anaesthetic and fresh gases and transcutaneous and blood gases in 24 patients. The noise level was low with a mean value under regular operating-room conditions around 45 dB(A) in the low frequency range. It is concluded that using the scavenging conditions provided by the system, the Swedish limits for anaesthesiologists' gas exposure could be reduced to the levels recommended by the US National Institute of Occupational Safety and Health (25 ppm for nitrous oxide and 0.5 ppm for halothane).

Adolescent↗
PubMed1985

Acetylcholine and aromatic amine systems in postmortem brain of an infant with Down's syndrome.

Adult cases of Down's syndrome often show histologic and biochemical changes comparable to those seen in severe Alzheimer's disease, but it is not known whether these are congenital or acquired defects. Cell counts of the basal forebrain cholinergic system innervating the cortex in a 5.5-month-old male infant with Down's indicated about 50% of the number of cells expected at birth but this is in the range of cell numbers found in healthy middle-aged normals. The noradrenergic system of the locus ceruleus has the expected complement of cells for normal newborns. The activities of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), glutamate decarboxylase, and tyrosine hydroxylase in a number of brain regions are reported for this infant, two cases of crib death, and a group of normal adults. The regional distributions of the enzymes in the infants were generally as expected from adult control data except for that of ChAT in one of the two cases of crib death; the AChE activities seemed extraordinarily high, especially in the case of Down's syndrome. Data on the concentrations of the catecholamines, serotonin, and their metabolites are also given but, like the enzyme data, are difficult to interpret in the absence of controls for the neonatal period.

Acetylcholine↗