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Biomedical subjects

D Armstrong

Publications and source records attributed to D Armstrong.

At least 217 records · Page 12Linked to original sources
PubMed1996

Urbanisation and coronary heart disease mortality among African Americans in the US South.

STUDY OBJECTIVE: Despite significant declines since the late 1960s, coronary mortality remains the leading cause of death for African Americans. African Americans in the US South suffer higher rates of cardiovascular disease than African Americans in other regions; yet the mortality experiences of rural-dwelling African Americans, most of whom live in the South, have not been described in detail. This study examined urban-rural differentials in coronary mortality trends among African Americans for the period 1968-86. SETTING: The United States South, comprising 16 states and the District of Columbia. STUDY POPULATION: African American men and women aged 35-74 years. DESIGN: Analysis of urban-rural differentials in temporal trends in coronary mortality for a 19 year study period. All counties in the US South were grouped into five categories: greater metropolitan, lesser metropolitan, adjacent to metropolitan, semirural, and isolated rural. Annual age adjusted mortality rates were calculated for each urban status group. In 1968, observed excesses in coronary mortality were 29% for men and 45% for women, compared with isolated rural areas. Metropolitan areas experienced greater declines in mortality than rural areas, so by 1986 the urban-rural differentials in coronary mortality were 3% for men and 11% for women. CONCLUSIONS: Harsh living conditions in rural areas of the South precluded important coronary risk factors and contributed to lower mortality rates compared with urban areas during the 1960s. The dramatic transformation from an agriculturally based economy to manufacturing and services employment over the course of the study period contributed to improved living conditions which promoted coronary mortality declines in all areas of the South; however, the most favourable economic and mortality trends occurred in metropolitan areas.

Adult↗
PubMed1996

Mixed neuronal-glial tumors (gangliogliomas) in children.

Mixed tumors account for about 10% of the childhood central nervous system tumors. Studies of the most common tumor, the ganglioglioma, in patients of all ages suggest that optimal therapy is total gross resection. There are few studies on these tumors in children. In our institution between 1984 and 1993, 28 children with gangliogliomas (4 of which were anaplastic) and 4 children with dysembryoplastic neuroepithelial tumors were treated and followed. Fourteen had local subarachnoid involvement. Total gross resection was usually curative, regardless of histology. Subarachnoid involvement was not indicative of a poorer prognosis.

Adolescent↗
PubMed1996

Preventive effect of natural and synthetic antioxidants on lipid peroxidation in the mammalian eye.

Lipid peroxidation was initiated with 5 mM ferric iron and aliquots of bovine or porcine retina, purified rod outer segments (ROS) and retinal pigment epithelium (RPE). After 30 min of oxidation, the lipid hydroperoxide content of the tissues increased approximately 4- to 8-fold over control levels with ROS showing the greatest change and RPE the lowest. Eight lipid and aqueous antioxidants from natural or synthetic sources and five flavonoids were evaluated for their ability to inhibit the reaction. Species differences were observed with regard to the fraction under study. Palm oil-derived vitamin E showed significant protection in bovine retina, ROS and RPE. In the porcine eye, the major defense was also afforded by vitamin E, but MCLA and other compounds such as EPC-K1 and U74500A were all quite active at 10(-5) M concentration. Of the flavonoids tested, partial protection in the bovine retina was found at 10(-5) M levels for epigallocatechin gallate (EGCg), quercetin, diosmetin and pycnogenol. When vitamin E and EGCg or quercetin were combined, the individual effect was enhanced. These results demonstrate the usefulness of an in vitro model system that can rapidly and accurately determine the capacity of antioxidants against lipid peroxidation.

Animals↗
PubMed1996

Abnormalities of retinal metabolism in diabetes or experimental galactosemia. III. Effects of antioxidants.

Effects of antioxidants on hyperglycemia-induced alterations of retinal metabolism were evaluated in rats diabetic or experimentally galactosemic for 2 months. Oxidative stress was estimated by measuring lipid peroxides (measured as thiobarbituric acid reactive substances [TBARS]) in retina and plasma. Erythrocyte osmotic fragility, another measure of oxidative stress, also was determined in the same groups of rats. In diabetic rats, TBARS were elevated by 74% in retina and 87% in plasma. In galactose-fed rats, TBARS were significantly elevated in retina (P < 0.05), but were normal in plasma. The administration of supplemental dietary ascorbic acid and alpha-tocopherol acetate for 2 months prevented the elevation of retinal TBARS and the decrease of Na(+)-K(+)-ATPase and calcium ATPase activities in retinas of diabetic animals without having any beneficial effect on plasma TBARS. In galactosemic rats, these antioxidants had a partial beneficial effect on the activity of retinal Na(+)-K(+)-ATPase, but failed to have any effect on calcium ATPase. The beneficial effects of antioxidants in diabetes and experimental galactosemia were not caused by the amelioration of hyperglycemia or retinal polyol accumulation. Erythrocyte osmotic fragility was increased by more than twofold in diabetes, but was normal in experimental galactosemia, and antioxidants prevented diabetes-induced increases in erythrocyte osmotic fragility-Diabetes-induced increased oxidative stress and subnormal ATPase activities in the retina can be inhibited by dietary supplementation with antioxidants.

Animals↗
PubMed1996

Intragastric pH during treatment with omeprazole: role of Helicobacter pylori and H. pylori-associated gastritis.

BACKGROUND: Omeprazole treatment produces lower intragastric pH values 4 weeks after cure of Helicobacter pylori infection than before. We therefore investigated the effect of healing H. pylori-associated gastritis on intragastric pH in the presence and in the absence of omeprazole therapy. METHODS: Before and on day 8 of omeprazole, 20 mg once daily, 24-h intragastric pH-recordings were performed in 14 subjects with H. pylori infection and repeated 4 and 52 weeks after cure of infection. Gastritis severity in corpus and antrum was graded by using a modified Sydney system. RESULTS: In the absence of omeprazole administration, median 24-h pH values before cure did not differ from those 4 and 52 weeks after cure. On day 8 of omeprazole administration, 24-h pH values were much higher before cure (median, 5.15; 95% confidence interval (CI), 4.3-6.0) than 4 weeks (3.6; 2.1-4.4; P < 0.001) and 52 weeks after cure (3.0; 2.1-4.4; P < 0.001). The activity of corpus and antral gastritis was not associated with the magnitude of H+ change induced by omeprazole. CONCLUSION: The increased pH produced by omeprazole during H. pylori infection is likely to be due to neutralizing substances produced by H. pylori and not to H. pylori-induced gastritis.

Adult↗
PubMed1996

Helicobacter pylori infection and dyspepsia.

It has proved remarkably difficult to confirm or refute an association between Helicobacter pylori-induced gastritis and non-ulcer dyspepsia for several reasons. Dyspepsia has not been defined adequately and current definitions include a variety of symptoms that probably reflect a number of underlying pathophysiological processes. Dyspepsia is a symptom complex, rather than a specific disease entity, and cannot be easily identified. There are probably many causes of dyspepsia, and if H. pylori does cause symptoms, it may produce different symptoms in different people. However, little is known about variations in host susceptibility and H. pylori virulence, or their potential effect on symptomatology. In addition, the mechanisms responsible for dyspeptic symptoms are unknown, regardless of whether or not there is concomitant H. pylori-induced inflammation. A possible aetiological role for H. pylori in dyspepsia has been sought in three major types of study. Epidemiology studies have suggested that H. pylori is not a major cause of non-ulcer dyspepsia. However, both dyspepsia and H. pylori are common, and the studies cannot account for many of the variables detailed above. Pathophysiological studies have commonly reported a variety of motor and sensory 'abnormalities' in association with H. pylori, but none has been confirmed or reproduced. In eradication studies, there is continuing debate as to whether dyspeptic symptoms diminish with treatment. This is partly because of the high placebo-response rate and partly because many treatment regimens have not cured the infection. Suppression of bacterial growth may not affect symptoms significantly, if they are due to mucosal inflammation, and symptom resolution may take many weeks or months following cure of H. pylori and the associated gastritis. Recent findings have shown that symptom reduction is more evident 1 year after eradication of H. pylori than after 4 weeks. There is a continuing and urgent need for well-designed studies to assess the long-term effect of H. pylori and its cure on both gastrointestinal function and dyspeptic symptoms.

Drug Therapy, Combination↗
PubMed1996

Abnormal ocular enhancement in Sturge-Weber syndrome: correlation of ocular MR and CT findings with clinical and intracranial imaging findings.

PURPOSE: To estimate the prevalence of abnormal ocular enhancement in children with Sturge-Weber syndrome as detected with MR imaging and CT and to correlate this with the clinical, fundoscopic, and intracranial imaging findings. METHODS: Fifteen children, 4 years old or younger, with Sturge-Weber syndrome were examined with enhanced CT and MR imaging. Eleven children had unilateral intracranial involvement and 4 had bilateral involvement, for a total of 19 abnormal hemispheres and related orbits. The presence of ocular enhancement was compared with the fundoscopic findings independently. Ocular enhancement was correlated with the extent of leptomeningeal disease, the severity of the cutaneous lesion, and the presence of glaucoma by the calculation of likelihood ratios and 95% confidence limits. RESULTS: Seven of the 15 patients had abnormal ocular enhancement, which was present in 10 (53%) of the eyes associated with the 19 abnormal hemispheres. MR imaging showed choroidal hemangioma in 7 of 8 patients in whom hemangiomas were shown at fundoscopy. The likelihood of ocular enhancement was increased with the presence of bilateral disease, extensive facial nevi, and glaucoma; there was no significant correlation with the extent of hemispheric involvement. CONCLUSION: Both enhanced MR imaging and CT can show diffuse choroidal hemangioma in patients with Sturge-Weber syndrome. However, MR imaging is more sensitive and is recommended to aid in the detection of abnormalities with preventable late complications.

Brain↗
PubMed1996

Choroid plexus size in young children with Sturge-Weber syndrome.

PURPOSE: To assess the size of the choroid plexus in young children with unilateral and bilateral Sturge-Weber syndrome. METHODS: Subjects included 15 children 4 years old or younger with Sturge-Weber syndrome. Eleven cases were unilateral and four were bilateral. Unilateral or bilateral involvement was determined by the distribution of abnormal leptomeningeal enhancement on MR images. The diameters of the choroid plexus were measured on contrast-enhanced axial MR images. The choroid plexus of the affected and unaffected sides in these cases were compared with those of 15 age-matched children without Sturge-Weber syndrome who were being examined for seizures. RESULTS: Our results show a wide variation in the size of the choroid plexus in children with Sturge-Weber syndrome; however, plexus associated with a hemisphere affected by Sturge-Weber syndrome were significantly larger than those on the unaffected side and in the age-matched control group. The size of the choroid plexus was positively correlated with the extent of leptomeningeal involvement as demonstrated by abnormal contrast enhancement. CONCLUSION: The choroid plexus is enlarged early in the course of Sturge-Weber syndrome in both unilateral and bilateral cases. There is a positive correlation between choroid plexus size and extent of leptomeningeal involvement in children with Sturge-Weber syndrome.

Child, Preschool↗
PubMed1996

Infectious complications of autologous bone marrow and peripheral stem cell transplantation for refractory leukemia and lymphoma.

We aimed to characterize the infectious complications of autologous bone marrow (AuBMT) and peripheral stem cell transplantation (PSCT) in patients with refractory leukemia and lymphoma. We performed a retrospective analysis of all patients (n = 56) with refractory leukemia or lymphoma treated with AuBMT or PSCT at Memorial Sloan-Kettering Cancer Center from January 1993 to July 1994. Records were available in 55, of whom 33 (60%) received AuBMT and 22 (40%) PSCT. Fifteen (27%) developed complicated infections, including 13 (39%) treated with AuBMT and two (9%) with PSCT. Complicated infections were caused by bacterial (11 episodes), fungal (four episodes), and viral (four episodes) pathogens. Five (9%) infections were fatal. In a multivariate model, only duration of neutropenia was significantly associated with development of complicated infection (P = 0.006). Thus, 27% of patients with refractory leukemia or lymphoma treated with AuBMT or PSCT developed complicated infections and 9% died of infection. Prolonged neutropenia was significantly associated with development of infection. Patients receiving PSCT had significantly lower rates of complicated infection, presumably due to the associated shorter duration of neutropenia. Future studies are needed to define the role of PSCT as treatment for refractory neoplastic disease.

Adult↗
PubMed1995

Mycobacterium haemophilum infections in bone marrow transplant recipients.

The purpose of this study was to describe the clinical presentation, treatment, and outcome of Mycobacterium haemophilum infection in patients undergoing bone marrow transplantation at a cancer center. Bone marrow transplant recipients with M haemophilum infection were identified upon culture of the organism by implementing the organism's unique requirements for growth. This report of the patients' clinical and immunologic course is based on a retrospective chart review. Two distinctly different presentations of M haemophilum infection were observed. Three patients presented with cutaneous lesions, typical of those seen in previous reports of the infection. Two others developed pulmonary disease only. All patients received directed therapy against M haemophilum, but respiratory failure developed in the patients with pneumonia and they died. The remaining 3 patients survived and are free of infection. These are the only reported cases of M haemophilum infection in bone marrow transplant recipients. Early diagnosis obtained through biopsy and special request for culture conditions conducive to the growth of the organism may decrease morbidity and mortality, particularly in patients with pulmonary disease.

Adult↗
PubMed1995

Patients' views of priority setting in health care: an interview survey in one practice.

OBJECTIVES: To explore the assumptions underlying consumers' responses to questions of resource priorities in the NHS. DESIGN: Qualitative analysis of semi-structured interviews with a heterogeneous sample of 16 patients drawn from a general practice. RESULTS: Interviewees were not persuaded that they had a legitimate role to play in the prioritisation of services. They supported the principle of equity and were reluctant to use their own personal needs as a basis for resource allocation; instead they argued from what they perceived to be the needs of others. CONCLUSIONS: Paradoxically, surveys of consumers' views on health care priorities probably do not elicit the personal ideas of respondents but tap into a more general ideological position closer to an earlier collectivist notion of health care.

Adult↗
PubMed1995

Consultants' workload in outpatient clinics.

The impact on hospital resources of variability in referral rates among general practitioners was of concern throughout the 1980s. The overall number of patients referred to outpatient clinics, however, has increased only slowly since the NHS began; in contrast, the number of new outpatients seen by each hospital consultant has declined appreciably. Ironically, despite this decline, further increasing the number of consultants in now being presented as a solution to the demand for outreach clinics in general practice.

Ambulatory Care↗
PubMed1995

Direct observations of surgical wound infections at a comprehensive cancer center.

OBJECTIVES: To identify the rate of surgical site infection and risk factors for surgical site infection in patients with cancer and to evaluate antibiotic use patterns on surgical oncology services. DESIGN: Criterion standard. SETTING: Memorial Sloan-Kettering Cancer Center, a comprehensive cancer center at a university hospital. PATIENTS: Over a 15-month period, 1226 patients undergoing 1283 surgical procedures performed by the Breast, Colorectal, and Gastric-Mixed Tumor surgical services. MAIN OUTCOME MEASURE: Direct observation of surgical sites was performed by a single, surgeon-trained member of the hospital's Infection Control Section, adhering to an established protocol for grading of the surgical site. RESULTS: Operative procedures accounted for the following traditional wound class distributions: class I (clean), 630 cases; class II (clean-contaminated), 577 cases; class III (contaminated), 29 cases; and class IV (dirty-infected), 47 cases. Surgical site infection rates were 3.8% in class I; 8.8% in class II; 20.7% in class III; and 46.9% in class IV procedures. The mean (+/- SD) age was 57.7 +/- 14.3 years and the Anesthesiology Society of America physical assessment score, 2.3 +/- 0.7. The mean (+/- SD) operation time was 145 +/- 104.9 minutes. Logistic regression analysis demonstrated several risk factors for surgical site infection: obesity (P < .0001); a contaminated or dirty-infected surgical procedure category (P < .0001); operation time greater than 4 hours (P = .0004); Anesthesiology Society of America physical assessment score of 3 or greater (P < .01); and preoperative length of stay of 3 or more days (P = .03). CONCLUSIONS: Risk factors for surgical site infection in patients with cancer are similar to those found in the National Nosocomial Infections Surveillance System. However, as an individual risk factor among our patient population, obesity contributed as strongly as the surgical procedure category to a patient's likelihood of acquiring a surgical site infection. In addition to Anesthesiology Society of America status, length of the surgical procedure, and surgical procedure category, obesity should warrant consideration as an individual risk factor for surgical site infection.

Adult↗
PubMed1995

Monobloc and facial bipartition osteotomies: quantitative assessment of presenting deformity and surgical results based on computed tomography scans.

PURPOSE: The results of monobloc (MB) or facial bipartition (FB) osteotomies on 23 consecutive patients operated on between 1987 and 1991 were evaluated. PATIENTS AND METHODS: A previously described method of clinically relevant linear measurements taken from preoperative and postoperative computed tomographic scans of these patients was used to document their presenting dysmorphology and the results of surgical correction initially and 1 year after operation. These data were compared with control values, and a percentage of normal for each measurement was derived for each patient. RESULTS: In the patients with craniofacial dysostosis undergoing an MB osteotomy, the initial cranial vault length (87% of normal), medial orbital wall length (87%), zygomatic arch length (84%), and extent of globe protrusion (134%) all indicated horizontal (anterior-posterior) deficiency of the upper and middle face. After surgery, these measurements moved closer to age-matched control values. At the 1-year interval a minor degree of relapse was evident. In the patients with craniofacial dysostosis who were believed to need an FB osteotomy, the globe protrusion (142% of normal), medial orbital wall length (85%), and zygomatic arch lengths (83%) all indicated horizontal (anterior-posterior) deficiency in the upper and middle face. In addition, the anterior interorbital distance (123% of normal), mid-interorbital distance (122%), and intertemporal distance (126%) all indicated upper face hypertelorism. As a result of the FB osteotomy, anterior bony projection was achieved, and the hypertelorism was improved, but fell short of age-matched normal values. In the patients with frontonasal dysplasia, cranio-orbital clefting, and isolated orbital hypertelorism who underwent an FB osteotomy, preoperative measurements showed a distinct widening of the whole upper midface with forward projection of the medial relative to the lateral orbital walls. The orbital measurements revealed a substantially widened anterior interorbital distance (175% of normal), increased mid-interorbital distance (123%), and an increased distance between the lateral orbital walls (106%). After the surgical procedure, these measurements were improved and relatively stable but not completely normalized. CONCLUSION: The use of quantitative measurements in the initial evaluation, intraoperative skeletal reshaping, and assessment of early and late reconstructive results provides useful benchmarks.

Acrocephalosyndactylia↗
PubMed1995

A corporate needs assessment for the purchase of district nursing: a qualitative approach.

A qualitative research methodology was applied to a corporate assessment of need for district nursing services. Semi-structured interviews were held with district nurses and the transcripts analysed for common themes. The major determinants of district nurses' roles were the priorities and practices of other community-based services, particularly social services and primary care. Purchasing and contract setting in this area needs to focus more on the interface with other services.

Attitude of Health Personnel↗