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Biomedical subjects

J Hawkes

Publications and source records attributed to J Hawkes.

16 recordsLinked to original sources
PubMed1995

Detection of aldehydes and their conjugated hydroperoxydiene precursors in thermally-stressed culinary oils and fats: investigations using high resolution proton NMR spectroscopy.

High field (400 and 600 MHz) proton NMR spectroscopy has been employed to investigate the thermally-induced autoxidation of glycerol-bound polyunsaturated fatty acids present in intact culinary frying oils and fats. Heating of these materials at 180 degrees C for periods of 30, 60 and 90 min. generated a variety of peroxidation products, notably aldehydes (alkanals, trans-2-alkenals and alka-2,4-dienals) and their conjugated hydroperoxydiene precursors. Since such aldehydes appear to be absorbed into the systemic circulation from the gut in vivo, the toxicological significance of their production during standard frying practices is discussed.

Aldehydes↗
PubMed1994

Degradation of hyaluronate by Streptococcus intermedius strain UNS 35.

Streptococcus intermedius strain UNS 35, a brain abscess isolate, produced extracellular hyaluronidase when grown in brain heart infusion broth. Chemical assays with this enzyme indicated that hyaluronate depolymerisation resulted in the formation of carbohydrate moieties with N-acetylglucosamine at the reducing terminal and containing an unsaturated carbon-carbon double bond. The nature of the products of this hyaluronidase were investigated further by high-field (400 MHz) proton (1H) NMR spectroscopy. Treatment of hyaluronate with the enzyme resulted in a series of new, sharp resonances in spectra (acetamido methyl group singlets located at 2.03 and 2.07 ppm, sugar ring proton multiplets in the 3.5-4.2 ppm chemical shift range, and doublets at 5.16 and 5.87 ppm) characteristic of low-M(r) oligosaccharide species, predominantly those containing glucuronosyl residues with delta 4,5-carbon-carbon double bonds. Comparison of spectra acquired from hyaluronidase-treated samples with that of an authentic sample of 4-deoxy-L-threo-hex-4-enopyranosyluronic-acid-N-acetylglucosamine (delta UA GlcNAc) indicated that this disaccharide was a major product arising from the actions of this enzyme. When used in minimal media, hyaluronate supported growth of S. intermedius, with lactate as the major metabolic end-product.

Carbohydrate Sequence↗
PubMed1994

Mood swings in patients with panic disorder.

Depression is frequently found in patients with panic disorder. It is known that patients suffering from panic disorder and depression have more severe symptoms of anxiety and avoidance and respond less well to treatment with antidepressants. The General Behaviour Inventory, an instrument that identifies subjects with subsyndromal and syndromal recurrent mood disorders was completed by 108 patients in a panic disorder program. Thirty-four percent (n = 37) were classified as suffering from a mood disorder. Of the mood disordered patients, 25 of 37 (68%) (23% of the total) were classified as suffering from bipolar or cyclothymic mood disorder.

Adult↗
PubMed1994

Phenelzine reduces plasma vitamin B6.

Plasma levels of the active form of vitamin B6 (pyridoxal phosphate) in 19 patients taking phenelzine were found to be reduced on the average to approximately 54% of the value in a control group. There was no correlation of pyridoxal phosphate level with phenelzine daily dosage over the range of 30 mg to 90 mg. No symptoms of vitamin B6 deficiency peripheral neuropathy were found.

Adolescent↗
PubMed1985

Feed preferences of ponies.

Preference trials were conducted with mature ponies. In Trial 1, oats were compared with oats plus sucrose. Four of six pony geldings selected oats plus sucrose, but one pony demonstrated a dislike for sucrose and one selected from the bucket on the right side regardless of content. Oats, maize, barley, rye and wheat were compared in Trial 2 using six mature pony mares. Oats were the preferred grain, with maize and barley ranking second and third respectively. Wheat and rye were the least preferred. Even though the ponies demonstrated preference, the total intake at a given meal was not greatly depressed when only the less palatable grains were fed. In Trial 3, pony mares selected a diet containing 20 per cent dried distillers' grain and 80 per cent of a basal mixed diet of maize, oats, wheat bran, soybean meal, limestone and molasses over 100 per cent basal mixed diet, but selected the basal diet over diets containing 20 per cent blood meal, beet pulp or meat and bone meal and 80 per cent basal diet. They did not differentiate against diets containing 20 per cent alfalfa meal or 10 or 5 per cent meat and bone meal when the diets were compared to the basal mixed diet.

Animal Feed↗
PubMed1983

The pathology of the human locus ceruleus.

The number of nerve cells of locus ceruleus and their nucleolar volume were determined in 63 normally aged individuals and in 41 cases with neurologic diseases. Pathologic alterations, such as a severe nerve cell loss and atrophy with or without extensive neurofibrillary degeneration or Lewy body formation, were generally seen in the nucleus locus ceruleus in Alzheimer's disease, Down's syndrome, dementia pugilistica, Parkinson's disease, and progressive supranuclear palsy, but such changes were only slight in normally aged individuals and minimal in motor neuron disease. Protein synthetic capacity was substantially reduced in the remaining nerve cells of the locus ceruleus, in Alzheimer's disease, Down's syndrome, and dementia pugilistica, but was unaltered in normally aged individuals (even in extreme old age), in motor neuron disease, and in the few remaining cells in Parkinson's disease and progressive supranuclear palsy. It is suggested that the pathologic alterations in the locus ceruleus found in these diseases, in conjunction with changes in the hypothalamus, lead to impairment of mental ability with eventual dementia through disturbance of the function of those pathways regulating homeostasis within the central nervous system.

Adult↗
PubMed1982

The noradrenergic system in Alzheimer and multi-infarct dementias.

The number of melanin containing nerve cells of the locus coeruleus and vagus nucleus is reduced in Alzheimer's disease by 60% with decrease of 22% in the protein synthetic capability of remaining cells. These changes are matched by reductions in brain noradrenaline in eight regions, averaging 36%. In multi-infarct dementia, however, all three of these features are unchanged. These findings indicate that degeneration of central noradrenergic nerve cells is a specific aspect of the pathogenic process underlying Alzheimer's disease.

Aged↗
PubMed1980

Low-dose insulin for treatment of diabetic ketoacidosis in a private community hospital.

We evaluated 21 patients with the diagnosis of diabetic ketoacidosis, involving 25 admissions to a large private community hospital, to evaluate the efficacy of low-dose insulin therapy by measuring time required for correction of hyperglycemia and acidosis, and to evaluate any associated morbidity or mortality. The protocols and laboratory tests were relatively loose and less stringent than our previous protocols, to permit flexibility of therapy by various physicians and to simulate the prevailing practice in such a hospital. All patients responded with correction of hyperglycemia within nine hours and acidosis within 12 hours, with averages of 5.61 and 6.8 hours, respectively. No deaths were recorded in the group. From these data, it is apparent that the low-dose insulin regimen is a safe, effective, and practical method for therapy of DKA in the private community hospital.

Adult↗
PubMed1978

Immunoradiometric assay of salivary anti-c3 antibodies.

By an immunoradiometric assay IgA and IgG anti-C3 antibodies were found in adult parotid salivas. The binding of the IgA antibodies to complement coated red cells could be reversed by washing in buffer containing 0.01 M EDTA but IgG antibodies were unaffected. The binding of IgA antibodies was inhibited by small quantities of purified C3. This assay may prove useful in the detection of anti-C3 antibodies in other body fluids.

Adult↗
PubMedDate not supplied

Immunohistochemical staining of senile plaques.

Immunohistochemical staining of serum proteins, including immunoglobulins, was carried out on formalin-fixed cerebral tissue from 24 autopsy cases (twenty dements, four controls) and fifteen biopsy cases (ten dements, five controls). Sixteen of the autopsy cases showed focal regions where there was staining of globulins and other serum proteins within senile plaque 'cores', nerve cell perikarya and astrocytes. This pattern of staining, generally, occurred either in relation to areas of cerebral infarction or in the neighbourhood of small arteries displaying arteriosclerotic changes. In tissue areas, distant from these vascular alterations, no staining occurred. Furthermore, none of the biopsy cases showed any such areas of staining. These findings indicate that the positive immunohistochemical reactions demonstrated within senile plaques (and other tissue components) are more likely to result from leakage of serum proteins, including immunoglobulins out of damaged vessels and into the brain parenchyma, rather than being indicative of the involvement of immunological mechanisms in the aetiology of plaques, as has been suggested by other workers.

Aged↗