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Biomedical subjects

R Holder

Publications and source records attributed to R Holder.

70 records · Page 4Linked to original sources
PubMed1987

Pulsatile secretion of TSH in healthy subjects.

The physiological variations in serum TSH concentration have been investigated using an enzyme amplified immunoassay with improved sensitivity and precision. Blood samples were collected at regular intervals from 10 healthy volunteers during the period 1800 h to 0100 h. Spectral analysis followed by periodic regression analysis demonstrated significant serum TSH pulsatility with periodicities of 60 or 85-100 min. In addition, a significant (P less than 0.001) evening rise in serum TSH concentration was demonstrated in all subjects, with levels rising at around 21.30-22.00 h.

Adult↗
PubMed1986

Long-term trends in biochemical data obtained from two population surveys.

A study has been made of the variations in monthly mean values of 10 serum constituents in subjects participating in two partly-concurrent long-term epidemiological surveys. Closely similar patterns of variation were found in men in both surveys and in men and women in one survey. During the 6 years of the study, four types of variation of the monthly mean concentrations were identified in varying combinations: abrupt changes of less than 2% not detected by quality control procedures; a gradual drift in mean value; haphazard variations in mean values; and seasonal variations in bilirubin and urea, identical in men and women. The implications of these findings for the design of long-term epidemiological surveys, and the criteria for designating variations as seasonal, are discussed.

Adult↗
PubMed1984

Low plasma C4 concentrations: association with microangiopathy in insulin dependent diabetes.

Plasma C4 concentrations were measured in insulin dependent diabetics with and without microangiopathy and in controls. The diabetics had significantly lower C4 values than controls (p less than 0.001), and patients with insulin dependent diabetes and microangiopathy had lower values than those without this complication (p less than 0.001). There was a 7.1-fold increase in the prevalence of complications in the diabetics with low C4 values. Of 41 diabetics whose rate of albumin excretion was measured, 13 had increased rates and 11 of these had low C4 concentrations. Low plasma C4 concentration in insulin dependent diabetes is strongly associated with microvascular disease and may identify diabetics with a particular propensity to develop this complication.

Adolescent↗
PubMed1984

Ultrasonography as an adjunct to pregnancy assessments in the mare.

Ultrasonographic detection of pregnancy was performed in 952 Thoroughbred mares. Characteristic images were obtained between 12 and 55 days after breeding. Twins in the same uterine horn as well as twins in opposite horns were imaged, and for the first few months of gestation appeared similar to single pregnancies. Growth curves as a function of time were developed, utilizing horizontal diameters of the blastocysts versus breeding dates. Comparisons between horizontal and vertical diameters demonstrated no appreciable differences when observed as a group. Growth curves derived from twins did not differ significantly from those for single pregnancies during the period we observed them. Ultrasonographic evaluations were valuable in substantiating mechanical destruction of one of the twin blastocysts immediately following the maneuver. Uterine artifacts such as endometrial and lymphatic cysts also were visualized and portrayed. Although these structures represented a source of false-positive results, they usually could be properly identified on the basis of their morphometric and growth characteristics.

Animals↗
PubMed1984

Cardiovascular and biochemical responses to nebulised salbutamol in normal subjects.

When conventional therapeutic doses of nebulised salbutamol were given to normal volunteers, there was a significant rise in pulse rate, systolic blood pressure and plasma glucose and a significant fall in diastolic blood pressure and serum potassium in comparison with placebo. Such changes may be potentially hazardous in certain situations. Patients with airways obstruction due to chronic bronchitis who have coexistent ischaemic heart disease or diuretic induced hypokalaemia may be at particular risk from the unwanted cardiovascular and biochemical responses to nebulised salbutamol.

Adult↗
PubMed1983

Can the biochemical responses to a beta 2-adrenoceptor stimulant be used to assess the selectivity of beta-adrenoceptor blockers?

The extent to which beta-adrenoceptor blocking drugs counteract the biochemical responses to an infusion of terbutaline, a beta 2-adrenoceptor agonist, has been investigated. In this study the beta 1-selectivity of metoprolol was compared with the non-selective beta-adrenoceptor blocker propranolol. The hypokalaemia produced by an infusion of terbutaline was reduced by low dose (50 mg) and high dose (200 mg) metoprolol and by low dose (40 mg) and high dose (160 mg) propranolol. The effects of propranolol on terbutaline induced hypokalaemia were more marked than those of metoprolol at both low dose (P = 0.01) and high dose (P = 0.05). Furthermore low dose metoprolol had less effect than high dose metoprolol (P = 0.05). The serum potassium appeared to rise slightly after propranolol. Low and high doses of both beta-adrenoceptor blockers markedly reduced the terbutaline-induced hyperglycaemia, but the differences between the two drugs were not statistically significant.

Adrenergic beta-Agonists↗
PubMed1975

The influence of drugs and disease activity on biochemical and haematological data in rheumatoid arthritis.

Biochemical and haematological data from 218 patients with rheumatoid arthritis were analysed and compared with data from a reference hospital population. The comparison demonstrated significant differences in several biochemical and haematological tests and that the patterns of change are different between males and females. The data were also analysed by conventional statistical methods and discriminant analysis using a computer to establish which tests were most influenced by the activity of the disease and drug therapy. The results obtained demonstrate marked difference between groups of patients with different disease activity or receiving different drugs. The discriminant analysis also identified those tests which differentiate these groups most effectively.

Arthritis, Rheumatoid↗
PubMedDate not supplied

The Adaptive Behaviour Dementia Questionnaire (ABDQ): screening questionnaire for dementia in Alzheimer's disease in adults with Down syndrome.

The diagnosis of dementia in Alzheimer's disease remains at times problematic in adults with intellectual disability. The analysis of 5-year consecutive data developed a researched-based clinical screening tool for dementia in Alzheimer's disease in adults with Down syndrome. The Adaptive Behaviour Dementia Questionnaire (ABDQ) is a 15-item questionnaire, which is used to detect change in adaptive behaviour. The scale has good reliability and validity, with an overall accuracy of 92%. It is the first clinical tool designed specifically to screen for dementia in Alzheimer's disease in adults with Down syndrome.

Adaptation, Psychological↗
PubMedDate not supplied

Can greater muscularity in larger individuals resolve the 3/4 power-law controversy when modelling maximum oxygen uptake?

BACKGROUND: The power function relationship, MR = a.m(b), between metabolic rate (MR) and body mass m has been the source of much controversy amongst biologists for many years. Various studies have reported mass exponents (b) greater than the anticipated 'surface-area' exponent 0.67, often closer to 0.75 originally identified by Kleiber. AIM: The study aimed to provide a biological explanation for these 'inflated' exponents when modelling maximum oxygen uptake (max), based on the observations from this and previous studies that larger individuals develop disproportionately more muscle mass in the arms and legs. RESEARCH DESIGN AND SUBJECTS: A cross-sectional study of 119 professional soccer players from Croatia aged 18-34 was carried out. RESULTS: Here we confirm that the power function relationship between max and body mass of the professional soccer players results in an 'inflated' mass exponent of 0.75 (95% confidence interval from 0.56 to 0.93), but also the larger soccer players have disproportionately greater leg muscle girths. When the analysis was repeated incorporating the calf and thigh muscle girths rather than body mass as predictor variables, the analysis not only explained significantly more of the variance in max, but the sum of the exponents confirmed a surface-area law. CONCLUSIONS: These findings confirm the pitfalls of fitting body-mass power laws and suggest using muscle-girth methodology as a more appropriate way to scale or normalize metabolic variables such as max for individuals of different body sizes.

Adolescent↗
PubMedDate not supplied

Urinary transferrin excretion in type 1 (insulin-dependent) diabetes mellitus.

Urinary excretion of transferrin and albumin was studied by radioimmunoassay in 47 adult patients with Type 1 diabetes and 28 control subjects. Median (range) urinary transferrin excretion rate was significantly elevated in the diabetic group 0.58 (0.02-2663.3) micrograms min-1 compared with the control group 0.04 (0.01-0.28) micrograms min-1, p less than 0.001. Urinary transferrin:creatinine ratios (x 10(2)) were different in diabetic 47 (0.6-958.0) micrograms mmol-1 and control groups 0.7 (0.06-2.3) micrograms mmol-1, p less than 0.001). There were correlations between urinary transferrin and albumin excretion rates in diabetic (r = 0.78, p less than 0.001) and control groups (r = 0.81, p less than 0.05). Forty (85%) diabetic patients had elevated transferrin excretion rates, 18 (38.3%) had elevated albumin excretion rates. All diabetic patients with elevated albumin excretion rates had elevated transferrin excretion rates. Twenty-one (77.8%) of the patients with normal albumin excretion rates had elevated transferrin excretion rates. Urinary excretion of N-acetyl-beta-D-glucosaminidase was greater in diabetic patients than control subjects (142 vs 58 mumol h-1 l-1, p less than 0.001). There were correlation between transferrin and N-acetyl-beta-D-glucosaminidase excretion (r = 0.67, p less than 0.01) and albumin and N-acetyl-beta-D-glucosaminidase excretion (r = 0.63, p less than 0.01) in the diabetic group. Elevated urinary transferrin excretion rate may be a marker for renal dysfunction in diabetes mellitus.

Acetylglucosaminidase↗
PubMedDate not supplied

Growth of an ameloblastoma during pregnancy: opportunity lost?

A 19-year-old pregnant woman presented with an enlarging lesion in the right mandible. She was examined by a general dental practice resident in the hospital outpatient clinic and subsequently managed by the resident as an inpatient. Both moral and ethical questions arose because of the discovery of the lesion early in the patient's pregnancy. Delay on the part of the patient while she contemplated termination of the pregnancy, compounded by loss of contact with her, eliminated the possibility of removal of the lesion during the second trimester. The patient elected to continue the pregnancy, and an en bloc procedure was used to remove the ameloblastoma.

Adult↗
PubMedDate not supplied

Glycogen storage disease and von Willebrand's disease implications for dental treatment: dental management of a pediatric patient.

Glycogen storage diseases (GSD) are metabolic disorders which impair the body's ability to store glucose and utilize it later, requiring patients to take multiple daily dietary supplementation with a high carbohydrate content. Patients undergoing this treatment modality are placed at increased risk for gross dental caries and other oral abnormalities. Additionally, GSD may prolong the patient's bleeding time, which may necessitate consultation with the treating physician. In the following case, our patient required a multidisciplinary approach to address not only her dental needs, but also to coordinate the management of both her GSD and an additional complication, von Willebrand's disease. This was best achieved in a hospital setting.

Child, Preschool↗
PubMedDate not supplied

Considerations in the management of the pregnant patient.

Traditionally, general dentists have been reluctant to treat pregnant patients due to uncertainty of the risks that might be imposed on both the mother and the fetus. However, preventive, emergency, and routine dental procedures are all suitable during various phases of a pregnancy, with some treatment modifications and initial planning. This article will review some of the physiologic changes and oral pathology associated with pregnancy, and how these alterations affect dental care for the patient. A brief discussion concerning the risks and benefits of radiation, certain medications, and pre-natal fluoride is also given. Additionally, an overview of possible obstetric emergencies that may arise during a general dental appointment is presented with treatment options outlined.

Dental Care↗
PubMedDate not supplied

Strength of posterior composite repairs using different composite/bonding agent combinations.

Posterior composites are becoming a viable alternative to amalgam in selected cases. As the use of posterior composites increases, the necessity of repair of fractured, discolored, or worn restorations will increase. A number of studies have demonstrated that clinically acceptable repairs can be obtained for anterior composites. This study examined the bond strength of repairs made to aged posterior composite substrates when different bonding agent/composite pairs were used. Dentin bonding agent/composite pairs gave the highest bond strengths and were greater than the bond strength of resin to etched enamel. An enamel bonding agent/composite repair gave the lowest bond strengths, which were less than resin/etched enamel bond strengths.

Analysis of Variance↗