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Biomedical subjects

J Cook

Publications and source records attributed to J Cook.

At least 217 records · Page 12Linked to original sources
PubMed1985

An evaluation of pneumatic orthoses in thoracic paraplegia.

Pneumatic orthoses were used to mobilise eight post-traumatic thoracic paraplegic males whose progress was monitored for two years. The pneumatic orthosis was more likely to be used than pelvic brace and calipers mainly due to increased support for the pelvis and the thoracolumbar spine. The effects of the orthosis and the mobilisation upon patient physiology were studied. Beneficial effects upon cardiovascular and respiratory systems were noted and increases in total body calcium after mobilisation were found. Contraindications to fitting the orthosis include severe spasms, obesity and scoliosis.

Adult↗
PubMed1985

Perinatal events which precede periventricular haemorrhage and leukomalacia in the newborn.

Ultrasound brain scans were obtained daily for the first 5 days after birth, on day 7 and then weekly until discharge from hospital in 86 babies during a 12-month period. The babies weighed less than 1501 g or were less than 34 weeks gestational age. Fifty-one (59%) had normal scans, 34 (40%) developed periventricular haemorrhage, and seven (8%) developed periventricular cysts (associated with periventricular haemorrhage in six). Factors associated with periventricular haemorrhage were perinatal hypoxia, acidosis, hypercapnia and hypoxia after birth. Babies who developed periventricular cysts (periventricular leukomalacia) were more likely to have been hypoxic at birth and in four of the seven there had been a maternal antepartum haemorrhage. The association of perinatal hypoxia with periventricular haemorrhage and leukomalacia suggests that intrapartum events may predispose to the onset of these lesions which then develop postnatally. Prevention of perinatal hypoxia may play an important role in diminishing the disability caused by these conditions.

Brain Diseases↗
PubMed1985

Persistent hypertransaminasemia as the presenting finding of childhood muscle disease.

Four children with isolated, persistent elevations of serum transaminases were investigated for hepatic disease and followed for 4 to 24 months before serum creatine kinase determinations were obtained and found to be markedly elevated. Evidence of muscle disease was obtained by close questioning, retrospectively, and mild abnormalities were found on physical examination. Review of laboratory tests in our center for 6 months revealed 30 additional cases of anicteric hypertransaminasemia (20% of those with elevated enzymes), only two of which were unexplained by the admitting diagnosis. Serum transaminase values are elevated in a variety of diseases of different organ systems. Creatine kinase determinations may provide the clue to the diagnosis of occult muscle disease in some children with unexplained anicteric hypertransaminasemia.

Adolescent↗
PubMed1985

Thymocyte cyclic AMP and cyclic GMP response to treatment with metabolites issued from the lipoxygenase pathway.

Evidence has been presented that cGMP is the second messenger for the lipoxygenase metabolites 15-HETE and LTB4 in the mouse splenocyte and thymocyte. Incubation of splenocytes with 10(-7) to 10(-9) M 15-HETE caused a slight decrease in cAMP levels and an increase in cGMP levels after 10 to 20 min. Mature PNA-, immature PNA+, and whole thymocytes treated with 10(-7) to 10(-10) M 15-HETE and 10(-11) M LTB4 showed an approximately 100% increase in cGMP production. In mixed lymphocyte reactions, 15-HETE- and LTB4-treated PNA+, PNA-, and whole thymocyte populations inhibited thymidine uptake by fresh allostimulated splenocytes. These results demonstrate that the eicosanoid-induced generation of suppressor cells follows a rise in lymphocyte cGMP levels.

Animals↗
PubMed1984

Effect of inverted body position on intraocular pressure.

We evaluated changes in intraocular pressure in eyes with primary open-angle glaucoma after inversion into a totally dependent position with the head down and compared them with the changes intraocular pressure in healthy nonglaucomatous eyes. Five minutes after inversion, intraocular pressure increased from 16.8 mm Hg +/- 2.8 (sitting) to 32.9 mm Hg +/- 7.9 in normal eyes and from 21.3 mm Hg +/- 2.3 (sitting) to 37.6 mm Hg +/- 5.0 in glaucomatous eyes. Although visual fields were unchanged after inversion, glaucomatous eyes may be particularly susceptible to such changes and unable to withstand the transient but significant increase in intraocular pressure that occurs after assuming an inverted position. We recommend that patients with ocular hypertension or glaucoma refrain from this activity.

Adult↗
PubMed1984

Increased frequency of diabetes mellitus in patients with bullous pemphigoid: a case-control study.

A case-control study was designed to assess the occurrence rate of primary diabetes mellitus (DM) in patients with bullous pemphigoid (BP) by retrospectively reviewing the records of our thirty histopathologically and immunopathologically proved cases of BP from the past 10 years. One hundred twenty patients were selected as controls, which included two names immediately before and two names immediately after each case of BP in our histopathology record book. The occurrence rate of primary DM prior to the administration of systemic corticosteroids was significantly higher in patients with BP than in the controls (20% and 2.5%, respectively; p = 0.004). Among patients over 50 years of age, this occurrence rate was again higher in patients with BP than in the controls (23% and 3.6% respectively; p = 0.02). This study suggests a higher than chance association of BP and primary DM.

Adolescent↗
PubMed1984

Structure of the proteolipid protein extracted from bovine central nervous system myelin with nondenaturing detergents.

As a basis for attempts to define the structures of the proteins within myelin, methods have been developed for their extraction and isolation in solutions of non-denaturing detergents. With use of solutions of deoxycholate or Triton X-100, up to 90% of the protein has been extracted from bovine CNS myelin, along with most of the phospholipid. The proteolipid protein has been purified in deoxycholate solutions by chromatography on a blue dye-ligand column, which retained all of the basic protein and 2',3'-cyclic nucleotide-3'-phosphodiesterase, and then on Sephacryl S300, which separated proteolipid protein from phospholipid and high-molecular-weight proteins. The proteolipid protein was isolated from Triton X-100 extracts of myelin by adsorption onto phosphocellulose resin, with subsequent elution by 0.5 M sodium chloride. Gel permeation chromatography was used as the final purification step. Sedimentation equilibrium experiments gave a monomer molecular weight of 134,000 +/- 8000 in deoxycholate and 145,000 +/- 17,000 in Triton X-100 solutions. On the basis of an apparent subunit molecular weight of 23,500 it was deduced that the native protein is probably hexameric. Above 0.2 gL-1 in Triton X-100 solutions and 0.5 gL-1 in deoxycholate solutions the protein aggregated. In deoxycholate solutions the protein adopts the highly helical conformation expected for an intrinsic membrane protein.

Animals↗
PubMed1984

Iron and blood donation.

Regular blood donors undergo a progressive decline in iron reserves, while some develop frank iron-deficient erythropoiesis. The prevalence of iron depletion is significantly higher in menstruating women and increases progressively as the rate of donation increases. While conventional screening programmes based on the haemoglobin are adequate to prevent the development of progressive iron deficiency anaemia, they provide no indication of the development of tissue iron depletion. Recent studies indicate an impairment in a number of physiological processes associated with iron depletion but the liabilities of mild iron deficiency have not been fully defined. While it would be desirable to avoid iron depletion in regular blood donors only a minority of the eligible population have been willing to provide the blood resources of the USA in the past, and many individuals who can maintain high rates of donation without developing iron deficiency anaemia would be eliminated. However, there is little doubt that continued efforts should be made to encourage a broader base of volunteer donors. Improved public awareness of the need for blood has made it possible to obtain 88 per cent of the total supply from donors who gave blood three or less times during the year, and only 13.4 per cent of men and 11 per cent of women made three of more donations (Table 6). Further, women under 46 years of age constitute only 1 per cent of all donors who give four or more times during the year. Until clear-cut evidence is obtained of the deleterious effects of a lack of iron, the low prevalence of depleted iron reserves in men and non-menstruating women donors seems acceptable. However, current blood banking practices place a disproportionate iron demand on menstruating women. Because of the additional burden of pregnancy in this donor group, efforts to reduce the prevalence of a lack of iron in the child-bearing female should be encouraged. The simplest approach would be to limit the rate of blood donation to a maximum of three per year. This also is a subgroup among whom the application of more specific screening procedures for iron deficiency can clearly be justified. Iron supplementation programmes are also an attractive approach in these people who are likely to be highly motivated. Neither of these approaches have been adequately evaluated at the present time.

Administration, Oral↗
PubMed1984

Distribution of immunoglobulin-bearing cells in the gut-associated lymphoid tissues of the turkey: effect of antibiotics.

Distribution of immunoglobulin (Ig)-bearing cells in the gut-associated lymphoid tissues of antibiotic treated and untreated control turkeys (Meleagris gallopavo) was compared. Antibiotic treatment was similar to a regimen used in commercial turkey production, which included preincubation dipping of fertile eggs in gentamicin solution, injection of turkeys with gentamicin at hatching, and inclusion of chlortetracycline in the diet. Tissues were examined from turkeys at 3, 7, 14, and 21 days of age with a direct immunofluorescence procedure. Cell distribution in control turkeys was as follows: In the bursa of Fabricius, IgA-carrying cells predominated at 3 days of age, but at later intervals, the 3 classes of Ig-bearing cells were in equal numbers. In the cecal tonsils, IgM- and IgA-bearing cells were in larger numbers at 3 days of age, whereas, the IgG-bearing cells were sparsely distributed. By 7 days of age, IgM cells became more numerous in the cecal tonsils and remained numerous until 21 days of age. At 3 days of age, IgA cells predominated in the small intestines and IgM cells predominated in the large intestine. At 7 and 14 days of age, IgM cells were more numerous in the small and large intestines, but by 21 days of age, IgA cell population equaled that of IgM. The IgG cells were generally sparse in the intestines. Antibiotic treatment often resulted in lower numbers of Ig-positive cells, especially those bearing IgM and IgA. Normal development of the bursa of Fabricius was also retarded in this group.

Animals↗
PubMed1984

Distribution of immunoglobulin-bearing cells in the gut-associated lymphoid tissues of the turkey: effect of oral treatment with intestinal microflora.

One-day-old turkeys (Meleagris gallopavo) were orally inoculated with the intestinal contents of an adult turkey, and the intestinal tissues were studied by immunofluorescence for immunoglobulin (Ig)-bearing cells at 3, 7, 14, and 21 days of age. Microflora inoculation increased numbers of Ig-bearing cells in the gut-associated lymphoid tissues; the most uniform effects were observed at 3 days of age. As the birds grew older, this uniformity in response to the microflora inoculation was not evident in all the tissues. In the bursa of Fabricius and the large intestine of the inoculated birds, IgM-bearing cells were more numerous throughout the study period. Compared with noninoculated control turkeys, IgA-bearing cells in the cecal tonsils, and IgG- and IgA-bearing cells in the small intestine were increased at all age intervals.

Aging↗
PubMed1984

Povidone-iodine: its efficacy as a preoperative conjunctival and periocular preparation.

Even though advances in aseptic care have reduced the incidence of endophthalmitis, the conjunctiva still is not sterilized for surgery. This article presents a simple preoperative preparative procedure which, in a series of 225 surgical cases, reduced the incidence of positive postoperative cultures to 9.6%, a much lower percentage than has been reported previously.

Conjunctiva↗
PubMed1983

lambda Phage cro repressor interaction with DNA.

We present here the complete identification of the resonances from the aromatic region of the 1H NMR spectrum of the cro repressor of the Escherichia coli lysogenic phage lambda. This was accomplished by the use of two-dimensional NMR analysis as well as specifically deuterated tyrosines. Not surprisingly, it shows that the published resonance assignment approached by more conventional methods by others includes substantial errors. The effect of complex formation with DNA was examined in the 1H NMR spectrum as well as in 19F NMR spectra from 3-fluorophenylalanine- or 3-fluorotyrosine-substituted cro repressors. The fluoro analogues show the practicality of using a structural gene cloned into an inducible system as a starting point to obtain both material and specific nuclear spin incorporation for NMR spectroscopy. The NMR data offer direct support for the speculative models of cro repressor-DNA complexes proposed from x-ray structure analysis on the protein alone.

Bacteriophage lambda↗
PubMed1983

Establishment of plasma membrane domains in hepatocytes. I. Characterization and localization to the bile canaliculus of three antigens externally oriented in the plasma membrane.

A membrane fraction denoted N2 upper was isolated from homogenates of rat liver by sucrose gradient centrifugation. This fraction, which was enriched 65-fold over the homogenate in 5'-nucleotidase activity, was used as an immunogen in goats. The antisera obtained contained antibodies to three predominant polypeptides in the N2 upper membrane fraction, as shown by crossed immunoelectrophoresis. These polypeptides had molecular weights of 105,000, 110,000, and 160,000 after recovery from the crossed immunoelectrophoretic gels and are denoted PM105, PM110, and PM160. Each was a distinct polypeptide, as shown by the distinct peptide patterns resulting from limited proteolysis in the presence of detergents. The three polypeptides were synthesized by primary cultures of hepatocytes and were externally oriented at the surface of these cells, as shown by their accessibility in situ to iodination catalyzed by lactoperoxidase. They were not detectable in the serum by crossed immunoelectrophoresis. The three antigens were present at very low (PM110) or nondetectable (PM105, PM160) concentrations in intracellular membrane fractions derived from the Golgi and smooth and rough endoplasmic reticulum of liver. The antigens also were reduced in concentration in a plasma membrane fraction most likely derived from the sinusoidal surface of the hepatocyte. The three membrane antigens bind to concanavalin A; hence, they are probably glycoprotein constituents of a discrete domain of the hepatocyte plasma membrane. Immune complexes were isolated after crossed immunoelectrophoresis and injected into rabbits. Each of the antisera obtained was reactive to one of the membrane polypeptides. Sections of fixed rat livers were reacted with each of the antibodies and then the primary antibody was localized by indirect immunocytochemical methods using horseradish peroxidase or colloidal gold as labels. Each of the three antigens was localized by this method to the bile canalicular domain of the hepatocyte plasma membrane.

Animals↗
PubMed1983

Comparison of polyvinyl alcohol- and formalin-preserved fecal specimens in the formalin-ether sedimentation technique for parasitological examination.

A total of 965 paired fecal specimens preserved in polyvinyl alcohol fixative and Formalin were processed by the Formalin-ether sedimentation technique. The effectiveness of the concentration procedures with material from each preservative was determined by comparing both diagnostic efficiency (percent identified) and quantitative egg and semiquantitative cyst counts. Of the 319 infections, 69.5% were detected in concentrates from both preservatives, 6.9% from polyvinyl alcohol only, and 23.5% from Formalin only. The egg and cyst counts were consistently higher from the specimens preserved in Formalin for most of the species of organisms recovered. These findings strongly support the use of Formalin-fixed specimens for the Formalin-ether concentration technique.

Ether↗