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Biomedical subjects

A Lee

Publications and source records attributed to A Lee.

At least 829 records · Page 46Linked to original sources
PubMedDate not supplied

Characterization of zona glomerulosa function in patients with classic and non-classic forms of congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency.

The function of the adrenal zona glomerulosa was studied in 18 patients with 11-hydroxylase deficiency confirmed by elevated plasma levels of 11-deoxycortisol. Patients were divided into two groups. Group I (4 males, 7 females; aged 1.2-2.8 yrs) had symptoms at birth or shortly after (classic form), and Group II (4 males, 3 females; aged 7.3-20.1 yrs) had their first clinical manifestation during childhood (non-classic form). To study zona glomerulosa function, patients were given dexamethasone p.o. 2 mg/m2/day x6 days, thus suppressing the zona fasciculata. Six hours after the last dose of dexamethasone, the zona glomerulosa was stimulated by i.v. administration of furosemide 1.0 mg/kg as a single dose. Blood was drawn 2 h later. In the untreated state, all patients had striking elevation of ACTH (Group I: 1,070 +/- 380 pg/ml; Group II: 764 +/- 180 pg/ml), 11-deoxycortisol (Group I: 63,000 +/- 22,000 ng/dl; Group II: 17,200 +/- 5,200 ng/dl) and deoxycorticosterone (Group I: 1,100 +/- 67 ng/dl; Group II: 499 +/- 27 ng%) while plasma renin activity (< 0.5 ng/ml/h in both groups) and aldosterone (Group I: 3.0 +/- 1.8 ng/dl; Group II: 2.3 +/- 1.8 ng/dl) were markedly suppressed. After the administration of furosemide 4 patients in Group I were unable to increase aldosterone (2.8 +/- 0.9 ng/dl) secretion in spite of marked elevation of plasma renin activity (28 +/- 7 ng/ml/h), suggesting an impairment of 11-hydroxylase in the zona glomerulosa.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

High prevalence of penicillin-nonsusceptible Streptococcus pneumoniae at a community hospital in Oklahoma.

During 1997, Oklahoma City's Hospital A reported penicillin-nonsusceptible Streptococcus pneumoniae in almost 67% of isolates. To confirm this finding, all Hospital A S. pneumoniae isolates from October 23, 1997, through February 19, 1998, were tested for antibiotic susceptibility and repeat-tested at two other hospital laboratories. Medical records of Hospital A patients with invasive S. pneumoniae infections during 1994 through 1997 were also reviewed. These data were compared with 1998 statewide sentinel hospital surveillance data for invasive S. pneumoniae. Of 48 S. pneumoniae isolates from Hospital A during October 23, 1997, through February 19, 1998, 31 (65%) were penicillin-nonsusceptible S. pneumoniae, and 23 (48%) were highly penicillin resistant. Similar prevalences were confirmed at the other hospital laboratories; however, significant interlaboratory differences were noted in the determination of third-generation cephalosporin susceptibility. During 1994 through 1997, a trend toward increasing penicillin nonsusceptibility (p <0.05) was noted among S. pneumoniae isolates from nursing home patients. During 1998, 85 (30%) of 282 invasive isolates reported to the state surveillance system were penicillin-nonsusceptible S. pneumoniae; 33 (12%) were highly resistant. The increase in resistance observed is notable; the interlaboratory discrepancies are unexplained. To respond, a vaccination program was implemented at Hospital A, and vaccination efforts were initiated at nursing homes.

Adolescent↗
PubMedDate not supplied

A case report of inflammatory pseudotumor involving the clivus: CT and MR findings.

The authors describe a rare case of inflammatory pseudotumor involving the clivus, where a soft tissue mass lesion, with extension into the prevertebral retropharyngeal space and the cavernous sinuses, was detected by CT and MRI. The mass resembled a malignant tumor or aggressive infectious lesion, and the final diagnosis of inflammatory pseudotumor was a diagnosis of exclusion, decided after histopathological examination.

Adult↗
PubMedDate not supplied

Stimulated C-peptide and glucose levels as metabolic criteria to use insulin treatment in adult-onset type II diabetes.

OBJECTIVE: To evaluate plasma C-peptide levels in middle-aged and elderly patients with type II diabetes, to clarify their practical use in assessing the need for insulin therapy, and to determine their sensitivity in distinguishing insulin-requiring from non-insulin-requiring diabetes after improved baseline glycemic control. METHODS: Plasma glucose and C-peptide levels were measured in a fasting state and 2 hours after an oral challenge with 100 g of glucose in groups of obese and normal-weight, glycemic-controlled, middle-aged and elderly patients with diabetes treated with insulin or an orally administered hypoglycemic agent (OHA). Basal and glucose-stimulated C-peptide levels as well as increased stimulated glucose values were contrasted in insulin- versus OHA-treated groups. In a second protocol, basal and glucose-stimulated C-peptide reactivity and stimulated glucose levels were also measured in eight patients with diabetes, before and after glycemic control. RESULTS: Irrespective of the age difference, stimulated C-peptide levels in the insulin-treated patients were significantly lower than those in the weight-matched OHA patients. Similarly, for both the middle-aged and elderly patients, stimulated glucose levels and degree of glucose elevation were higher in the insulin-treated patients. In the second protocol, as hyperglycemia was reduced, beta-cell secretion measured by C-peptide responses to glucose was significantly increased, in conjunction with a decrease in the stimulated glucose levels. CONCLUSION: These results indicate that measurements of C-peptide responses to glucose stimulation are helpful to determine the decision to use insulin in both elderly and middle-aged patients with diabetes. Blunted insulin responses identify those patients who require insulin treatment, whereas high C-peptide values in insulin-treated patients suggest the possibility of discontinuing insulin therapy.

Journal Article↗
PubMedDate not supplied

Classification of type 2 diabetes by clinical response to metformin-troglitazone combination and C-Peptide criteria.

OBJECTIVE: To assess the ability of basal and stimulated C-peptide levels and stimulated glucose values after oral administration of glucose to predict a successful response to metformin and troglitazone combination therapy after discontinuation of insulin therapy. METHODS: At the onset of the study, plasma glucose and C-peptide levels were measured in a group of 64 obese patients with insulin-treated type 2 diabetes while they were fasting and 2 hours after a challenge of 100 g of glucose administered orally. Then combination metformin-troglitazone treatment was initiated while insulin therapy was gradually tapered over 8 to 12 weeks. Subjects who successfully tolerated insulin withdrawal after the metformin-troglitazone combination were categorized as non-insulin-requiring responders, whereas those who needed insulin to obtain glycemic control were categorized as insulin-requiring nonresponders. Basal and glucose-stimulated C-peptide levels as well as stimulated glucose values were contrasted in the responder versus nonresponder groups. In a second protocol, eight obese patients with insulin-treated type 2 diabetes who successfully stopped insulin therapy were reassessed for C-peptide and glucose variables during the 2-hour oral glucose tolerance test. This reassessment followed a 12-week period of therapy to determine whether treatment of insulin resistance with the combination of metformin and troglitazone could normalize the impaired glucose tolerance in type 2 diabetes. RESULTS: After metformin-troglitazone therapy, 48 study subjects (75%) could later be managed without insulin, whereas 16 (25%) needed insulin to achieve acceptable glycemic control. In a comparison of the non-insulin-requiring responder and insulin-requiring nonresponder groups, the responder group had significantly higher glucose-stimulated C-peptide levels and much lower stimulated glucose levels. The mean basal plasma C-peptide level was higher in the responder than in the nonresponder group, but a small degree of overlap was found between the two groups. Combination treatment with metformin and troglitazone for 12 weeks resulted in a significant reduction in the C-peptide response and glucose variables after the glucose load. CONCLUSION: The results of this study indicate that stimulated C-peptide and glucose levels may be useful criteria to identify whether combination metformin-troglitazone treatment can successfully replace insulin therapy in the management of obese patients with type 2 diabetes. Inability to normalize glucose intolerance after restoring insulin resistance with insulin sensitizers is supportive of the presence of both disturbed beta-cell function and insulin resistance in patients with type 2 diabetes.

Journal Article↗
PubMedDate not supplied

The laboratory report: a problem in communication between clinician and microbiologist?

When writing a laboratory report, the microbiologist often makes certain assumptions as to the clinician's understanding of laboratory procedures and reporting practices. The effect of these assumptions on the interpretations of the reports is discussed, with data from a survey of general practitioners. Possible ways of improving communication between the laboratory and the clinician are suggested.

Bacteriology↗
PubMedDate not supplied

The use of serology to diagnose active Campylobacter pylori infection.

A serological test that predicts accurately active Campylobacter pylori infection in the human stomach has been developed and validated by means of serum from 189 patients who were undergoing endoscopy in Sydney. Our enzyme-linked immunosorbent assay (ELISA) has a sensitivity of 100% and a specificity of 94%. An important part of the test is the inclusion of a simple absorption step with C. jejuni for those sera whose results are close to the cut-off point for positivity. This has been shown to be particularly relevant in epidemiological studies on populations that are likely to be exposed to C. jejuni continually. For example, by means of the ELISA test without an absorption step, the infection rate in Papua New Guineans was shown to be 56%, whereas use of the validated test showed the infection rate to be 25%. Compared with an age-matched normal control group of Australians, this still is higher. These studies suggest a need for the reappraisal of some of the reported epidemiological data. The development of a validated diagnostic test that is a highly-accurate predictor of active C. pylori infection will be useful for epidemiological studies, particularly for comparative studies among populations that are known to differ significantly in the incidence of stomach disease. However, routine use of this test in diagnosis in general practice awaits the definition of more precise markers of C. pylori-associated symptomatology and the development of improved regimens for the treatment of C. pylori infections.

Adolescent↗
PubMedDate not supplied

Hats off to Angela.

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Adolescent↗
PubMedDate not supplied

Use of cornmeal bolus as an aid in obtaining cranial four-vessel angiograms.

In cranial angiography it has always been difficult to visualize extracranial vessels of the cervico-thoracic region, upon one radiograph, by using the same exposure factors for both regions. For this reason, we experimented and found that by applying a dry cornmeal bolus on specific areas of the neck a technically superior radiograph of these regions can be achieved. This bolus simulated added soft tissue to the cervical region. The density of the cervical region is now similar to that of the upper thoracic. As a result, factors set for one exposure will adequately penetrate both areas.

Cerebral Angiography↗