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Biomedical subjects

D Hinton

Publications and source records attributed to D Hinton.

35 records · Page 2Linked to original sources
PubMed1986

Trends in blood lead levels in Christchurch (NZ) and environs 1978-85.

Blood lead levels have been monitored since 1974 and have shown a significant decrease (p less than 0.001) from 1978 to 1985 in 2830 subjects from Christchurch and environs. From a baseline in August 1978-81 to August 1985 blood lead levels in a population which had no relevant exposure to lead other than that from the general environment have fallen in adult males and females (greater than 17 years) by 42%, and in school and pre-school children greater than 9 months by 44% and 46% respectively. Reduction of blood lead has accelerated during the last three years. This can be linked to changes in dietary intake and clean up of lead in domestic and industrial environments. Over this decade the lead content of petrol (0.84 g/l) and petrol sales have remained unchanged.

Adolescent↗
PubMed1986

Diurnal patterns of blood pressure, heart rate and vasoactive hormones in normal man.

In order to determine arterial pressure and vasoactive hormone relationships in normotensive man, we measured intra-arterial pressure continuously along with hourly venous hormone levels (renin, angiotensin II, aldosterone and catecholamines) for 24 hours in 5 healthy volunteers under standardized conditions. Mean 24-hour levels of intra-arterial pressure 106/63 +/- 5.4/4.9 mmHg were much lower than in patients with mild essential hypertension studied earlier. A common diurnal pattern was seen for plasma renin, angiotensin II, and catecholamines, with higher levels in the day time and lower levels at night. Aldosterone levels however, paralleled those of cortisol at night. Plasma norepinephrine levels showed close, positive correlations with arterial pressure in all volunteers. We conclude that the level of blood pressure as measured continuously over 24 hours is lower than might be expected from regular clinic recordings; that aldosterone regulation is contributed to by ACTH in the nocturnal hours; and that fluctuations in arterial pressure and sympathetic activity over 24 hours are closely coupled.

Adult↗
PubMed1985

Teamwork can improve the health of lead process workers.

A team working co-operatively to improve the health of lead workers has evolved over the last 10 years. We have monitored 704 employees for red cell lead (4800 samples) from a factory since 1974. In 1975, 32 employees, one-third of the workforce were suspended at a red cell lead level of greater than 10.7 mumol/l. Since 1980 no-one has been suspended at the current lower level of 7.7 mumol/l. By June 1984 the red cell lead mean for all process areas is less than 4.5 mumol/l (average 3.6 mumol/l). In 1984 the usual red cell lead range for local non-industrially exposed adult males is 1.23 SD 0.65 mumol/l. The value of cumulative reporting and contributory factors in reducing the blood levels are discussed.

Adult↗
PubMed1984

Industrial lead exposure: a review of blood lead levels in South Island industries, 1974-83.

Relative risks of increased lead absorption found in 31 occupations were investigated. Serial red cell lead measurements on 1319 males and 186 females provided a mean and range for each occupational type. The magnitude of the mean and percentage of raised levels identified the degree of occupational risk. The mean red cell lead for 50% of employees was within the regional usual range for those not occupationally exposed. In 77% the mean red cell lead was less than 4.1 mumol/l. Of the remainder, 4% had levels greater than 5.7 mumol/l and 1% had levels greater than 7.7 mumol/l. Our findings have been used to manage local chronic and acute lead problems.

Erythrocytes↗
PubMed1984

Neurochemical abnormalities in a patient with ataxia-telangiectasia.

We describe biochemical abnormalities found in autopsied brain of a patient with ataxia-telangiectasia. Neuropathologic changes were limited to the cerebellum and spinal cord. The atrophic cerebellum showed marked loss of Purkinje's and granule cells, and moderate loss of stellate and basket cells. Glutamic acid content was markedly reduced, and taurine content somewhat reduced in the cerebellar cortex, while gamma-aminobutyric acid (GABA) content was greatly reduced in the dentate nucleus. GABA receptor binding was reduced by 70% in cerebellar cortex. Phosphoethanolamine content was greatly reduced in the cerebellar cortex and inferior olivary nucleus. This compound was also deficient in 10 other brain regions and was the only extracerebellar neurochemical abnormality observed.

Ataxia Telangiectasia↗
PubMed1983

Steroid receptors in meningiomas. A histochemical and biochemical study.

Meningiomas are more common in females and their course can be affected by changes in the hormonal milieu of the patient. Recently, a few studies have reported the presence of one or more steroid receptors in a small number of meningiomas. We have studied the estrogen and progesterone receptors (ER and PgR) of 11 surgically excised meningiomas. The receptors were assayed biochemically and localized at the cellular level using fluoroceinated estradiol and rhodamine-conjugated progesterone. Considerable amounts of ER were found in 4/11 cases, and PgR was high in 6/11 tumors. Cytoplasmic localization of the steroid binding sites was seen using both tracers. The presence of 10% of cells with two ++ intensity of the fluorescence correlated with tumors having positive ER values (greater than 10 Fm/mg protein). The presence of nuclear fluorescence and the higher level of PgR seen in some tumors indicate that the ER present is functioning. This study confirms the presence of steroid binding sites in meningiomas and suggests that there may be a role for hormonal manipulation in selected patients.

Adult↗
PubMed1983

Primitive neuroectodermal tumors of the central nervous system.

Primitive neuroectodermal tumors are morphologically similar malignant tumors arising in intracranial and peripheral sites of the nervous system, showing varying degrees of cellular differentiation with a tendency to disseminate along cerebrospinal fluid pathways. They occur primarily in children and young adults. Under the designation primitive neuroectodermal tumors are included medulloblastomas and tumors that may differentiate in other directions, such as medulloepithelioma, neuroblastoma, polar spongioblastoma, pineoblastoma, ependymoblastoma, retinoblastoma, and olfactory neuroblastoma. From a practical, histologic point of view, these tumors are often indistinguishable from one another and are best thought of as primitive neuroectodermal tumors with or without differentiating features.

Animals↗
PubMed1983

Hirano-bodies in the distal symmetric polyneuropathy of the spontaneously diabetic BB-Wistar rat.

Lattice-like cytoplasmic inclusions have been demonstrated in a variety of pathologic conditions of the CNS and PNS in both man and animals. We describe 2 types of such inclusions occurring in association with the distal central-peripheral symmetric polyneuropathy of the spontaneously diabetic BB-Wistar rat. In the literature, both these lattice-like inclusions have been referred to as Hirano-bodies, but have not been separated on the basis of different measurements, locations or possible origins.

Animals↗
PubMed1981

Comparison of three methods to estimate steatorrhoea.

Faecal fat excretion was estimated in 24 patients using three methods. Quantitative estimations of fat excretion were calculated from both a three day faecal fat collection and a twenty-four hour faecal collection corrected for excretion of a cuprous thiocyanate marker. Breath 14CO2 excretion was measured after ingestion of a liquid meal containing 2.5 microCi of 14C-triolein in an arachis oil emulsion. Peak concentrations of 14CO2 in breath were used as an estimate of the degree of fat absorption. Correlation between the two quantitative measures of faecal fat was good (r = 0.87), 17 patients having steatorrhoea of more than 7 g fat per day by both estimations. Results of the breath test were disappointing. With the standard meal containing 20 g arachis oil the lowest peak 14CO2 excretion rate seen in subjects without steatorrhoea, 3 percent of the dose per hour, was taken as the lower limit of normal. Seven subjects with steatorrhoea as shown by faecal collections excreted normal amounts of 14CO2. When the size of the fat meal was increased to 1.0 g arachis oil per kg body weight in 16 of the subjects previously studied, all patients with proven steatorrhoea excreted less than 3 percent of the dose per hour but three of the subjects without steatorrhoea gave abnormal breath excretion results. It is concluded that the collection of a 24 hour faecal specimen using a cuprous thiocyanate marker provides a more reliable estimate of faecal fat excretion than the 14C-triolein breath test.

Breath Tests↗
PubMed1980

1,25-dihydroxy-vitamin D3: a new treatment for hypoparathyroidism.

Eleven subjects aged four to 76 years with primary hypoparathyroidism have been treated with 1,25-dihydroxycholecalciferol (1,25-D3). Five subjects were not on vitamin D analogues before starting this drug. 1,25-D3 was found to be an effective treatment and a rapid biochemical response to dose adjustments was observed. In two subjects hypercalcaemia and reversible renal failure occurred. Thiazide-type diuretics necessitated dose reductions in a further two subjects. A scheme for starting hypoparathyroid subjects on this treatment is suggested. The need for regular biochemical assessment and awareness of possible drug interactions is emphasised. It is felt that 1,25-vitamin D3 has practical advantages over traditional forms of vitamin D in the treatment of hypoparathyroidism.

Adult↗
PubMed1979

Primary hyperparathyroidism in a New Zealand community: a review of 40 cases.

Forty cases of primary hyperparathyroidism presenting over a 15 year period, have been reviewed. The disease was equally prevalent in both sexes with highest incidence in the sixth decade. Most patients presented with renal colic or calculi (73 percent) and skeletal disease was found in only 13 percent. A single parathyroid adenoma was found in 32 cases and hyperplasia was diagnosed in only two cases. Follow-up questionnaires were sent to 32 patients, and in 27 of these a full clinical and laboratory assessment was undertaken. Of 26 patients with renal colic preoperatively only six continued to experience colic one year after parathyroid surgery. Thirty percent of all patients were hypertensive preoperatively, and in only two patients did blood pressure normalise after surgery. Fourteen of 27 patients followed-up were found to be hypertensive. A highly significant fall was noted in serum calcium, chloride, alkaline phosphatase and urine calcium excretion postoperatively. Recurrence of the disease was low and less than 8 percent in this series. The low incidence (1 per 10 000 population per year) suggests that primary hyperparathyroidism is under diagnosed in the Christchurch community.

Adolescent↗
PubMed1977

The influence of glucagon on sodium retention after fasting.

Two groups of five obese female subjects, having undergone a ten day therapeutic fast, were fed with either glucose 50 g/day or with L-alanine 50 g/day for three days. Plasma glucagon concentrations and urinary electrolyte excretion were compared in the two groups. Although 4.00pm plasma glucagon concentrations during refeeding were significantly greater in the alanine refeed group (P less than 0.05) the reduction in urinary sodium excretion in each of the two groups was identical. These observations do not support the hypothesis that glucose induced suppression of plasma glucagon concentrations is a mechanism whereby carbohydrate refeeding produces post-fast urinary sodium retention.

Adolescent↗
PubMedDate not supplied

Panic disorder among Cambodian refugees attending a psychiatric clinic. Prevalence and subtypes.

This study surveys Khmer refugees attending two psychiatric clinics to determine both the prevalence of panic disorder as well as panic attack subtypes in those suffering panic disorder. A culturally valid adaptation of the SCID-panic module, the Cambodian Panic Disorder Survey (CPDS), was administered to 89 consecutive Cambodian refugees attending these psychiatric clinics. Utilizing culturally sensitive panic probes, the CPDS provides information regarding both the presence of panic disorder and panic-attack subtypes during the month prior to interview. Of 89 patients surveyed at two psychiatric clinics, 53 (60%) currently suffered panic disorder. Among the 53 patients suffering panic disorder, the most common panic attack subtypes during the previous month were the following: "sore neck" [51% of the 53 panic disorder patients (PDPs)], orthostatic dizziness (49% of PDPs), gastrointestinal distress (26% of PDPs), effort induced (21% of PDPs), olfactory induced (21% of PDPs), and "while-sitting dizziness" (16% of PDPs).

Adult↗
PubMedDate not supplied

Panic disorder among Vietnamese refugees attending a psychiatric clinic: prevalence and subtypes.

This study surveys Vietnamese refugees attending two psychiatric clinics to determine both the prevalence of panic disorder (PD) as well as panic attack subtypes in those suffering PD. A culturally valid adaptation of the SCID-panic module (the Vietnamese Panic Disorder Survey or VPDS) was administered to 100 Vietnamese refugees attending two psychiatric clinics. Utilizing culturally sensitive panic probes, the VPDS provides information regarding both the presence of PD and panic attack subtypes during the month prior to interview. Of 100 patients surveyed, 50 (50%) currently suffered PD. Among the 50 patients suffering PD, the most common panic attack subtypes during the previous month were the following: "orthostatic dizziness" (74% of the 50 panic disorder patients [PDPs]), headache (50% of PDPs), wind-induced/temperature-shift-induced (24% of PDPs), effort-induced (18% of PDPs), gastro-intestinal (16% of PDPs), micturition-induced (8% of PDPs), out-of-the-blue palpitations (24% of PDPs), and out-of-the-blue shortness of breath (16% of PDPs). Five mechanisms are adduced to account for this high PD prevalence as well as the specific profile of subtypes: 1) a trauma-caused panic attack diathesis; 2) trauma-event cues; 3) ethnic differences in physiology; 4) catastrophic cognitions generated by cultural syndromes; and 5) a modification of Clark's spiral of panic.

Ambulatory Care↗