Search PubMed⌕ Search

Biomedical subjects

D Ball

Publications and source records attributed to D Ball.

At least 109 records · Page 6Linked to original sources
PubMed1994

Effect of urinary macromolecules and chondroitin sulphate on calcium oxalate crystallization in urine.

After filtration and ultrafiltration (10 kD) of 24 hour urine specimens from 12 healthy male subjects, calcium oxalate crystallization was induced in the filtered (FILTD) and ultrafiltered (UF) fractions by administration of a sodium oxalate load. In addition crystallization was also induced in UF fractions to which physiological quantities of chondroitin sulphate (CHON) had been added (UF+CHON). The rate of calcium oxalate crystallization was determined by measuring the rate at which turbidity increased. Crystal numbers and sizes were measured with a Malvern particle size analyzer and by scanning electron microscopy. Crystallization rates, crystal numbers and crystal sizes were generally lower in UF fractions than in FILTD fractions suggesting that urinary macromolecules are promoters of calcium oxalate crystallization. No increase in crystallization rate, crystal numbers or sizes occurred when chondroitin sulphate was added to UF fractions, indicating that the promoter activity of urinary macromolecules is not due to this particular glycosaminoglycan. On the contrary, crystallization rates were qualitatively lower in UF+CHON fractions than in UF fractions alone, suggesting a possible inhibitory role for chondroitin sulphate in real urine. Scanning electron microscopy revealed that while aggregates were present in UF and FILTD fractions, they were absent in UF+CHON fractions. This observation indicates that chondroitin sulphate might be an inhibitor of calcium oxalate crystal aggregation in real urine.

Adult↗
PubMed1994

Radiation and carboplatin combined-modality therapy in non-small cell lung cancer.

Previously untreated patients with stages I to IV, N0-3, M0 unresectable non-small cell lung cancer were randomized to arm I (conventional radiotherapy [RT], 60 Gy in 30 fractions over 6 weeks), arm II (accelerated RT, 60 Gy in 30 fractions over 3 weeks), arm III (conventional RT, as in arm I, plus carboplatin 70 mg/m2/d on days 1 to 5 during treatment weeks 1 and 5), or arm IV (accelerated RT, as in arm II, plus carboplatin 70 mg/m2/d on days 1 to 5 of week 1 only). An intensive analysis of toxicity in the first 92 patients entered revealed significantly more neutropenia (P < .0001) and thrombocytopenia (P = .004) in the combined-modality arms. Esophagitis was worse on arms II, III, and IV, but was more prolonged in the accelerated RT arms. Overall, however, the treatment on all study arms was well tolerated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Urinary macromolecules are promoters of calcium oxalate nucleation in human urine: turbidimetric studies.

Calcium oxalate crystallization was induced in the filtered, ultrafiltered (10 kDa) and retentate fractions of 24-h urine specimens obtained from 15 male controls and 10 male stone formers, by administration of an aqueous sodium oxalate challenge to each test solution. Crystallization rates were followed by monitoring of the increase in turbidity in these fractions as a function of time. A laboratory nephelometer, previously calibrated against a Coulter counter, was used for this purpose. In addition, to facilitate interpretation of turbidity data, a Malvern particle size analyzer was used to determine crystal sizes and numbers in control urines. Crystallization rates, crystal numbers and crystal sizes were generally lower in ultrafiltered fractions than in filtered or retentate fractions, indicating that urinary macromolecules are promoters of calcium oxalate nucleation. Data for stone formers suggest that the urinary macromolecules in this group may be more potent nucleation promoters than those in controls.

Adult↗
PubMed1993

Longer survival with higher doses of thoracic radiotherapy in patients with limited non-small cell lung cancer.

PURPOSE: To determine if there is an effect of thoracic radiotherapy dose on survival in patients with non small cell lung cancer localised to the primary site and regional lymph nodes. METHODS AND MATERIALS: Nine hundred and forty-one previously untreated patients with limited non small cell lung cancer presenting at Peter MacCallum Cancer Institute during 1984-1989 inclusive, were planned to receive radiotherapy using one of three schedules: 20 Gy in five fractions; 30 or 36 Gy in 10 or 12 fractions; and 60 Gy in 30 fractions. The survival of patients in each of the groups was analysed to determine if there was an effect of dose on survival, before and after adjusting for the major prognostic factors, performance status and weight loss. RESULTS: The survival of patients planned to receive 60 Gy was significantly better than for patients planned to receive lower doses (p < 0.0001) with median survival increasing from 6.1 to 9.2 and 14.5 months for the 20 Gy, 30 or 36 Gy and 60 Gy groups, respectively. After adjusting for the effect of performance status and weight loss, death rates relative to the 20 Gy group were 79% (95% confidence interval: 67-93%) for patients planned to receive 30 or 36 Gy and 53% (95% confidence interval: 44-65%) for patients planned to receive 60 Gy. CONCLUSION: These data support the hypothesis that the increased survival in patients with limited non small cell lung cancer treated with higher dose radiotherapy is not due purely to patient selection.

Adult↗
PubMed1993

Chromosome abnormalities in non-small cell lung cancer pleural effusions: cytogenetic indicators of disease subgroups.

A cytogenetic study of pleural effusions (PE) containing metastatic or invasive tumor cells from 11 patients with non-small cell lung cancer (NSCLC) (3 squamous cell carcinomas [SQC] and 8 adenocarcinomas [ADC] including 1 giant cell variant) was performed to identify non-random chromosome abnormalities. Numerical abnormalities seen in > or = 30% of cases included gain of chromosomes 7 and 20, and loss of chromosomes 4, 9, 10, 13, 15, 16, 18, 19, 21, and 22. The most frequent structural abnormality involved rearrangement in 1p with breakpoints clustering at 1p10-p13. Other recurrent breakpoint regions, seen in > or = 30% of cases, occurred in chromosome region 3p10-p21, 3q11-q25, 6p11-p25, 6q13-q23, 7q11-q36, 9q32-q34, 11p11-p13, 11q13-q24, 13p/14p and/or 15p, 17p and 19p, with, in particular, apparent loss of 6q21-q27, 3p21-p26, 7q21-q22, 9p22-p24 (shortest regions of common overlap) and 17p. There was also recurrent gain of 1q23-q44, 8q13-q24, and 11q13-q23. These abnormalities were not restricted to a particular histological subtype, with the exception of +8 and a breakpoint in 9q32-q34, which were seen only in ADC. The 9q32-q34 breakpoint observed in 4 ADC PE (including 1 giant cell variant) represents a new observation in NSCLC. These findings, when compared to those reported for primary NSCLC indicate cytogenetic differences between the two which may be associated with pleural invasion of NSCLC.

Adenocarcinoma↗
PubMed1993

Influence of sodium bicarbonate ingestion on plasma ammonia accumulation during incremental exercise in man.

This investigation evaluated the influence of metabolic alkalosis on plasma ammonia (NH3) accumulation during incremental exercise. On two occasions separated by at least 6 days, six healthy men cycled at 70, 80, and 90% of maximum oxygen consumption (VO2max) for 5 min; each exercise period was followed by 5 min of seated recovery. Exercise was then performed at 100% VO2max until exhaustion. Beginning 3 h prior to exercise, subjects ingested 3.6 mmol.kg body mass-1 NaHCO3 (test, T) or 3.0 mmol.kg body mass-1 CaCO3 (placebo, P) (both equivalent to 0.3 g.kg-1) over a 2-h period. Trials were performed after an overnight fast and the order of treatments was randomized. Arterialized venous blood samples for the determination of acid-base status, blood lactate and plasma NH3 concentrations were obtained at rest before treatment, 15 s prior to each exercise bout (Pre 70%, Pre 80%, Pre 90%, and Pre 100%), and at 0, 5 (5'Post), and 10 (10'Post) min after exhaustion. Additional samples for blood lactate and plasma NH3 determination were obtained immediately after each exercise bout (Post 70%, Post 80%, Post 90%) and at 15 min after exercise (15'Post). Time to exhaustion at 100% of VO2max was not significantly different between treatments [mean (SE): 173 (42) s and 184 (44) s for T and P respectively]. A significant treatment effect was observed for plasma pH with values being significantly higher on T than on P Pre 70% [7.461 (0.007) vs 7.398 (0.008)], Pre 90% [7.410 (0.010) vs 7.340 (0.016)], and 10'Post [7.317 (0.032) vs 7.242 (0.036)].(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Saccadic eye movement parameters in normal subjects.

The present study obtained saccadic eye movements from 122 normal subjects to establish normative values and test-retest reliability data, using a recently developed electrooculographic recording and analysis system. Factors that might affect saccade values, such as age, sex, and time of day when testing, were also assessed. Mean (+/- S.D.) peak velocity values over saccade angles of 15 degrees, 25 degrees and 35 degrees were in agreement with those previously reported. Repeat testing in 11 subjects on 4 separate occasions showed that saccade measurements were consistent across tests. Several saccade parameters were significantly negatively associated with age for 35 degrees saccades. The association between age and peak velocity was examined in greater detail over a range of saccade angles, and the greatest effect was observed for saccades of > or = to 35 degrees. Diurnal changes in performance were observed, with a tendency for slightly slower values in the early afternoon. There were no significant differences between males and females.

Adolescent↗
PubMed1993

The dopamine D3 receptor gene: no association with bipolar affective disorder.

Bipolar affective disorder and schizophrenia share many clinical and genetic characteristics, and are thought by some to be different expressions of the same underlying disorder. A recent study showed an excess of homozygosity at a BalI polymorphism in the dopamine D3 receptor gene in schizophrenic patients compared with controls, from two independent centres. We have found no evidence of such an excess in a comparable sample of patients with bipolar affective disorder compared with matched controls. If these findings are confirmed then at least one genetic distinction between these two disorders will have been ascertained and doubt cast upon theories of a common genetic aetiology.

Alleles↗
PubMed1993

Preoperative localization of occult medullary carcinoma of the thyroid gland with single-photon emission tomography dimercaptosuccinic acid.

BACKGROUND: Patients who undergo thyroidectomy for medullary carcinoma of the thyroid gland (MTC) often have elevations of postoperative serum calcitonin levels, which are indicative of metastatic or residual disease. It has been extremely difficult to localize tumor in these patients with standard diagnostic studies such as ultrasonography, computed tomography, or magnetic resonance imaging scans. Previous studies have suggested that planar technetium 99m (V) dimercaptosuccinic acid (DMSA) scintigraphic scans can localize MTC in these patients. We have recently increased the sensitivity of planar scintigraphic images by using single-photon emission tomography (SPECT). This study was performed to compare the sensitivity of planar DMSA scans with that of SPECT DMSA scans. METHODS: Two normal volunteers and three patients with occult MTC after previous total thyroidectomy underwent planar and SPECT DMSA scans. Each patient subsequently underwent surgical exploration based on the DMSA scans. RESULTS: Physiologic DMSA uptake was noted in the nasopharynx, axial skeleton, breast, liver, spleen, heart, kidneys, urinary bladder, great vessels, and skeletal muscles in both normal volunteers and patients with occult MTC. Planar DMSA scans and dynamic computed tomographic scans failed to localize MTC in any of these patients who had minimal disease. SPECT DMSA scans correctly localized cervical MTC in two of three patients, as proved by subsequent surgical resection. One patient who had a negative cervical exploration is presumed to have had a false-positive SPECT DMSA scan. CONCLUSIONS: SPECT DMSA scans appear to be a sensitive, safe, and noninvasive localization technique for patients with occult MTC who have undergone previous thyroidectomy.

Adult↗
PubMed1992

Presymptomatic testing for Huntington's disease in the United Kingdom. The United Kingdom Huntington's Disease Prediction Consortium.

OBJECTIVE: To evaluate the United Kingdom Huntington's disease presymptomatic testing programme. DESIGN: Postal questionnaire survey to collect data on all tests performed by clinical genetics centres between 1987 and 1990. SETTING: Genetic centres providing presymptomatic testing in the United Kingdom. SUBJECTS: 248 subjects at risk of Huntington's disease who had presymptomatic testing at their request. MAIN OUTCOME MEASURES: Sex, age, prior risk, and risk after testing. RESULTS: The risk of carrying the Huntington disease gene was reduced for 151 (61%) of the applicants and raised for 97 (39%). 158 (64%) of the subjects were female and 90 (36%) male. The median age at which the results were given was 32.5 years. CONCLUSIONS: The demand for testing was lower than expected and may have reached its peak in 1990. The excess of low risk results was not fully explained by the age effect. All the genetics centres concerned have agreed a common service protocol which requires extensive pre-test counselling and post-test follow up. The worth of the procedure remains to be decided. The availability of a large body of pooled data from all the United Kingdom testing centres, which individually are likely to have only a few results, will form a valuable resource for monitoring the long term psychosocial impact of testing.

Adolescent↗
PubMed1992

Alpha-fetoprotein levels in normal adults.

Alpha-fetoprotein (AFP) is a fetal specific glycoprotein normally produced primarily by the fetal liver. Normally, AFP levels decline rapidly after birth, reaching undetectable levels (less than 10 ng/ml) within several months after birth. The authors have developed a more sensitive radioimmunoassay, which has allowed them to study low levels of AFP in normal adults and to determine factors which may affect its normal level. Two hundred and seventy normal Houston blood donors were screened for the absence of hepatitis B and normal ALT levels. The mean AFP level was 3.04 ng/ml +/- 1.9 SD. There was a statistically significant higher level in men compared to women (p less than .004). Regression analysis demonstrated a statistically significant increase of AFP levels with age both in men (p less than .05) and in women (p less than .01). These data delineate the normal level of serum AFP in normal adults in the United States. With the normal level now defined, it becomes possible to compare levels in different populations including those exposed to hepatotoxins or hepatocarcinogens in the environment.

Adolescent↗
PubMed1991

The influence of dietary manipulation on plasma ammonia accumulation during incremental exercise in man.

The influence of a pattern of exercise and dietary manipulation, intended to alter carbohydrate (CHO) availability, on pre-exercise acid-base status and plasma ammonia and blood lactate accumulation during incremental exercise was investigated. On three separate occasions, five healthy male subjects underwent a pre-determined incremental exercise test (IET) on an electrically braked cycle ergometer. Each IET involved subjects exercising for 5 min at 30%, 50%, 70% and 95% of their maximal oxygen uptake (VO2max) and workloads were separated by 5 min rest. The first IET took place after 3 days of normal dietary CHO intake. The second and third tests followed 3 days of low or high CHO intake, which was preceded by prolonged exercise to exhaustion in an attempt to deplete muscle and liver glycogen stores. Acid-base status and plasma ammonia and blood lactate levels were measured on arterialised venous blood samples immediately prior to and during the final 15 s of exercise at each workload and for 40 min following the completion of each IET. Three days of low CHO intake resulted in the development of a mild metabolic acidosis in all subjects. Plasma ammonia (NH3) accumulation on the low-CHO diet tended to be greater than normal at each exercise workload. Values returned towards resting levels during each recovery period. After the normal and high-CHO diets plasma NH3 levels did not markedly increase above resting values until after exercise at 95% VO2max. Plasma NH3 levels after the high-CHO diet were similar to those after the normal CHO diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1991

Limited small cell lung cancer: the effect of radiotherapy on local control following response to chemotherapy.

The survival and rate of chest infield relapse was examined in 48 patients with limited disease small cell lung cancer (LSCLC) who had achieved complete (CR) or partial response (PR) following three courses of chemotherapy. During 1985-1986 chemotherapy consisted of carboplatin and etoposide and during 1986-1987, of etoposide, carboplatin, cyclophosphamide, and vincristine (ECCO). After three courses of chemotherapy, chest irradiation (50 Gy in 25 fractions over 5 weeks) was given to encompass the original tumor volume. Complete responders were also given prophylactic cranial irradiation, 30 Gy in 10 fractions over 2 weeks. Overall median survival of all patients receiving chest irradiation was 17 months from commencement of radiotherapy. The infield relapse-free survival at 24 months was 49% (95% confidence interval: 32-66%). Patients who had only achieved a PR at the time of irradiation were more likely to relapse in the chest than complete responders (p = 0.09). We conclude that local relapse remains a major cause of failure in patients with LSCLC in spite of sequential high dose radiotherapy given to patients who have responded to chemotherapy.

Adult↗