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Biomedical subjects

T M Gross

Publications and source records attributed to T M Gross.

12 recordsLinked to original sources
PubMed2001

Is the process of beta-cell destruction in type 1 diabetes at time of diagnosis more extensive in females than in males?

OBJECTIVE: To evaluate sex differences in patients with insulin-dependent diabetes mellitus (type 1 diabetes) by comparing the integrated parameters of metabolic control at the time of clinical diagnosis and 3 months after intensive insulin therapy in pre-pubertal, pubertal and post-pubertal patients. DESIGN: A total of 331 consecutive patients with newly diagnosed type 1 diabetes were studied. The mean age of the group was 15 years (s.d. 8.1; range 5-23 years). Patients were stratified into three groups according to their age at disease onset: pre-pubertal (ages 5-9 years), pubertal (ages 10-18 years) and post-pubertal (ages 19-23 years). METHODS: Glycated haemoglobin (HbA(1c)), insulin dose and both basal and glucagon-stimulated C-peptide were evaluated at diagnosis and after 3 months of insulin therapy. RESULTS: We found that females diagnosed after puberty were those with the lowest basal C-peptide compared with males (P=0.005). No statistically significant differences were observed for other metabolic parameters. When the entire group was evaluated, females at the time of diagnosis showed significant lower body mass index (P=0.001), lower basal C-peptide (P=0.021) and higher HbA(1c) (P=0.023) and required more insulin than males (P<0.001). After 3 months of therapy, only a significantly greater dose of insulin was observed in females compared with males (P=0.001), with similar good metabolic control as assessed by HbA(1c). CONCLUSIONS: We conclude that the process of beta-cell destruction at diagnosis may be more extensive in post-pubertal females than in males. Moreover, after the introduction of insulin therapy, females and males show similar metabolic parameters, although females still require significantly more insulin than males to achieve good metabolic control, 3 months after diagnosis.

Adolescent↗
PubMed2000

Performance evaluation of the MiniMed continuous glucose monitoring system during patient home use.

BACKGROUND: The recent availability of a continuous glucose monitor offers the opportunity to match the demands of intensive diabetes management with a period of equally intensive blood glucose monitoring. The present study evaluates the performance of the MiniMed continuous glucose monitoring system (CGMS) in patients with diabetes during home use. METHODS: Performance data and demographic information were obtained from 135 patients who were (mean +/- SD) 40.5+/-14.5 years old, had an average duration of diabetes of 18.0+/-9.8 years, 50% were female, 90% were Caucasian, and 87% of whom had been diagnosed with type 1 diabetes. Patients were selected by their physician, trained on the use of the CGMS and wore the device at home for 3 days or more. The performance of the CGMS was evaluated against blood glucose measurements obtained using each patient's home blood glucose meter. Evaluation statistics included correlation, linear regression, mean difference and percent absolute difference scores, and Clarke error grid analysis. RESULTS: The CGMS values were compared to 2477 SMBG tests (r = 0.91, slope = 0.93, intercept = 14.5 mg/dL, mean absolute difference = 18.0%+/-19.8%). Clarke error grid analysis showed 96.2% of the data pairs falling within the clinically acceptable regions (zones A and B). CONCLUSIONS: These results demonstrate the agreement of the CGMS to blood glucose meter values, under conditions of home use, in patients selected by their physicians as candidates for continuous monitoring. The detailed glucose information provided by the CGMS should make successful management of diabetes more easily achieved.

Adult↗
PubMed1999

Continuous glucose monitoring used to adjust diabetes therapy improves glycosylated hemoglobin: a pilot study.

A 5-week pilot study was conducted to determine if continuous glucose monitoring could be used to improve glycemic control. A total of nine subjects with type 1 diabetes and HbA1c values greater than 8.5% completed the study. Subjects wore a continuous glucose monitor for two 1-week periods during the study. After each sensor use, changes to diet, insulin dosage and self-monitored blood glucose (SMBG) schedule were made. HbA1c decreased from 9.9% (S.D. = 1.1%) at baseline to 8.8% (S.D. = 1.0%) 5 weeks after baseline (P = 0.0006), but daily insulin usage was unchanged over the same period of time (P = 0.428). The glucose sensors performed accurately, with a median correlation of 0.92 and a mean absolute difference of 19.1% (S.D. = 9.0%). The continuous glucose profiles allowed identification of glucose patterns and excursions that helped direct changes in therapy. These treatment changes would not have been made on the basis of meter data alone and were effective in improving glucose control. Additional studies are needed to validate these findings. This pilot study highlights the potential for continuous glucose monitoring to provide the valuable information necessary to make therapy adjustments that can dramatically improve patients' glycemic control and reduce the risk of long-term complications.

Adolescent↗
PubMed1995

Enhanced lexical processing of smoking stimuli during smoking abstinence.

In a group of heavy smokers, overnight abstinence from smoking facilitated the perception of briefly presented smoking words. Subjects in the nicotine-abstinent condition accurately identified significantly more smoking-related words than food-related or neutral words. However, a group tested in a non-abstinent condition showed no significant differences in ability to identify the three different word types. Smokers deprived of cigarettes were also significantly better able to categorize smoking words than non-abstinent subjects. These results demonstrate an abstinence-based facilitation of processing smoking-related stimuli at the semantic level, consistent with the hypothesis that smoking-related concepts are activated, or primed, during deprivation from nicotine.

Adult↗
PubMed1995

Menthol vs nonmenthol cigarettes: effects on smoking behavior.

OBJECTIVES: The purpose of this study was to examine intraindividual differences in smoking behavior between smoking regular and mentholated cigarettes. METHODS: Healthy male smokers (n = 29) smoked either a regular or a mentholated cigarette in two separate sessions 1 week apart. Commercial brands with comparable tar, nicotine, and CO content were used. Smoking behavior was constrained by fixed 15-second interpuff intervals, but puff volume and number of puffs were unconstrained. RESULTS: When smoking the non-mentholated brand of cigarettes, participants smoked 22% more puffs and had 13% higher mean volumes per puff than they did when smoking the mentholated brand of cigarettes. The aggregate 39% excess exposure to cigarette smoke in the regular-cigarette condition was not accompanied by commensurate excesses in expired carbon monoxide or in physiological measures normally correlated with nicotine exposure. CONCLUSIONS: These findings parallel differences in physiological correlates of exposure to nicotine found in cross-sectional comparisons of African-American and White smokers and are consistent with the results of emerging laboratory investigations.

Adult↗
PubMed1994

From the archives of the AFIP. Musculoskeletal malignant fibrous histiocytoma: radiologic-pathologic correlation.

Malignant fibrous histiocytoma (MFH) is a pleomorphic sarcoma, occurring most frequently in the deep soft tissues of the extremities. Primary osseous MFH is less common. MFH is the most common soft-tissue sarcoma of late adult life. Although its imaging appearance is often nonspecific, any deep-seated invasive intramuscular mass in a patient over 50 years of age is most likely an MFH. Cortical involvement by soft-tissue MFH is common, and identification of this finding increases the likelihood of MFH. Prominent fluid components with peripheral nodular enhancement after contrast material administration and lack of adipose elements are suggestive of a specific histologic subtype, myxoid MFH. Osseous MFH shows aggressive bone destruction with cortical involvement and a soft-tissue mass and is located in the diaphysis or metaepiphysis. Lesions in the metaepiphysis may have a less aggressive appearance and do not extend to subchondral bone. Computed tomography and magnetic resonance imaging are vital for preoperative staging and surgical planning and in detecting early recurrence postoperatively.

Aged↗
PubMed1993

Nicotine abstinence produces content-specific Stroop interference.

Adult, male smokers were randomly assigned to be nicotine abstinent for 12 h (n = 10) or to smoke normally for the same period of time (n = 10). Performance on a modified version of the Stroop (1935) color-naming task, where subjects named the color of ink in which each of a series of words was written, showed that abstinent smokers took significantly longer to color-name words related to cigarette smoking (e.g., Lighter) than to color-name neutral control words (e.g., Pennant). Non-abstinent smokers showed a significant difference in the opposite direction. These results suggest that nicotine abstinence decreases the ability to ignore the meaning of smoking-related information. This finding supports the hypothesis that abstinence produces a content-specific shift in attentional focus. The present pattern of results cannot be explained by a general decrease in cognitive function due to nicotine abstinence.

Adult↗
PubMed1993

Rapid smoking of menthol and nonmenthol cigarettes by black and white smokers.

White subjects took significantly more puffs of cigarette smoke before stopping than did black subjects in a modified, controlled-dose rapid smoking procedure. Paradoxically, however, no racial differences were detected for changes in carbon monoxide levels, or changes in cardiovascular variables (systolic and diastolic blood pressure, and heart rate). Due to the cooling and topical anesthetic properties of menthol, it was hypothesized that menthol and regular cigarette smokers would take more puffs from menthol cigarettes than from regular cigarettes before stopping in the controlled-dose rapid smoking procedure. However, no difference was observed for the number of puffs taken from regular as opposed to menthol cigarettes (cigarette type condition) and no differences were found for Cigarette Preference (regular smokers vs. menthol smokers).

Adult↗
PubMed1993

Magnetic resonance imaging of soft tissue and cystic masses about the knee.

Magnetic resonance imaging (MRI) of the knee is the most frequently performed joint MRI examination. The use of MRI has revolutionized assessment of both intra-articular and periarticular musculoskeletal masses about the knee and has largely supplanted other radiologic methods of evaluation. The purpose of this article is to review the MRI appearance of the numerous types of soft-tissue and cystic masses that arise about the knee.

Cysts↗
PubMed1987

The glycosaminoglycan chondroitin-4-sulfate alters progesterone secretion by porcine granulosa cells.

Porcine granulosa cells from small (1-2 mm), medium (3-5 mm), and large (6-12 mm) antral follicles were cultured in monolayer for 2 to 3 days with 0 to 3 mg of chondroitin-4-sulfate (C-4-S)/ml in the presence or absence of 0.5 microgram follicle-stimulating hormone (NIH-FSH-S13)/ml. Testosterone (1.4 microgram/ml) was added to some cultures as substrate for estrogen synthesis. Progesterone and estrogen secreted into the media were measured by radioimmunoassay. Concentrations of C-4-S similar to concentrations of chondroitin sulfates (CS) reported for small antral or atretic follicles inhibited both basal and FSH-stimulated progesterone secretion. Progesterone secretion was not inhibited by C-4-S when pregnenolone was added to the media. Thus 3 beta-hydroxysteroid dehydrogenase activity was not inhibited by C-4-S. Estrogen secretion was also not inhibited by even the highest concentration of C-4-S tested. Testosterone did not influence C-4-S inhibition of progesterone secretion. Granulosa cells from medium-sized follicles were more sensitive to C-4-S than cells from small follicles. Granulosa cells from large follicles were completely resistant to C-4-S inhibition of progesterone secretion. These observations suggest that C-4-S may play a role in altering gonadotrophin-stimulated and basal progesterone secretion in follicles during differentiation of granulosa cells.

Animals↗