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Biomedical subjects

M Charron

Publications and source records attributed to M Charron.

At least 55 records · Page 3Linked to original sources
PubMed1995

Determinants of bone mineral density in older men.

Osteoporosis is a significant health problem and contributor to disability and premature mortality among older men. Incidence rates for hip fracture have stabilized in women, but continue to increase in men. A major risk factor for hip fracture is bone mineral density level. The determinants of bone mineral density (BMD) are well defined in women, but not in men. The primary goal of the current research was to increase our understanding of the determinants of BMD of the proximal femur in a large community-based sample of older male volunteers. Eligibility requirements included age of 50 years or older, ambulatory, and not having undergone a bilateral hip replacement. Five hundred twenty-three men, mean mean age 66.6 years, met all eligibility requirements and participated in the Study of Osteoporotic Risk in Men or STORM. Information on demographics, medical history, anthropometry, leisure-time and occupational physical activity, muscular strength, cigarette smoking, alcohol consumption, dietary calcium intake, and medication use (thiazide diuretics and glucocorticoids) were obtained by questionnaire, interview, and examination, BMD of the proximal femur (femoral neck, greater trochanter, and Ward's triangle) was measured by dual-energy X-ray absorptiometry using the Hologic QDR-1000 and QDR-2000. The cross-sectional determinants of BMD included age, blond hair color, current body weight, thiazide diuretic use, historical physical activity, and quadriceps strength. Several variables commonly thought to be determinants of BMD were not related to BMD in this population of older men, including current cigarette smoking, alcohol consumption, current leisure-time physical activity, dietary calcium intake, vitamin D use, and caffeine intake. However, failure to find associations among BMD and some of the potential determinants may be due to lack of statistical power. Identification of the determinants of BMD could lead to the development of interventions aimed at maximizing BMD in men and could potentially decrease the risk of hip fractures.

Absorptiometry, Photon↗
PubMed1995

Nuclear dacryoscintigraphy: its role in oral and maxillofacial surgery.

Obstruction of the lacrimal drainage apparatus may result in excessive tearing or epiphora. This may occur as a result of a traumatic injury or accumulation of debris, mucus, or pus. In nuclear dacryoscintigraphy, a radioactive solution is introduced into the conjunctival sac by pipette and allowed to follow the flow of the tear solution through the lacrimal drainage system. This article will review normal lacrimal anatomy and indications for nuclear dacryoscintigraphy in oral and maxillofacial surgery.

Humans↗
PubMed1995

Hypertrophic osteoarthropathy in a child with follicular bronchiolitis.

Hypertrophic osteoarthropathy (HOA) is a syndrome affecting the bones, soft tissue, and joints, often occurring in association with chronic pulmonary disorders. Radiography has traditionally been the imaging modality employed to confirm this diagnosis. However, radionuclide bone imaging provides a sensitive method for the detection of HOA and correlates well with the clinical manifestations. The authors's describe the case of a child with HOA in association with follicular bronchiolitis, a rare chronic pulmonary disorder, whose HOA was diagnosed by radionuclide imaging.

Bronchiolitis↗
PubMed1994

Pyuria and bacteriuria in urine specimens obtained by catheter from young children with fever.

Results of urinalysis and culture of 2181 urine specimens obtained by catheter from febrile children aged less than 24 months were analyzed to determine the following: (1) an optimal cutoff point in considering a bacterial colony count clinically "significant," (2) the accuracy of leukocyte esterase and nitrite tests in identification of pyuria and bacteriuria, and (3) the utility of pyuria (defined as > or = 10 leukocytes/mm3) in the discrimination of urinary tract infection from asymptomatic bacteriuria. Among 110 urine cultures with > or = 10,000 colony-forming units per milliliter, 92 (84%) had > or = 100,000 CFU/ml, 10 (9%) had 50,000 to 99,000 CFU/CFU/ml and 8 (7%) had 10,000 to 49,000 CFU/ml. Urine specimens with 1000 to 49,000 CFU/ml were more likely than specimens with > or = 50,000 CFU/ml to yield Gram-positive or mixed organisms (36/60 vs 7/109; p < 0.001). A count of < 10 leukocytes/mm3 was almost invariably associated with a sterile culture; a count of > or = 10 leukocytes/mm3 was found in 93 of 102 patients with > or = 50,000 CFU/ml. The dipstick leukocyte esterase test had sensitivities of 52.9% and 66.7% in detecting > or = 10 leukocytes/mm3 and > or = 20 leukocytes/mm3, respectively. The dipstick nitrite test had a sensitivity of 31.4% in detecting bacteriuria (> or = 50,000 CFU/ml). Acute pyelonephritis was diagnosed by a renal scan with dimercaptosuccinic acid labeled with technetium 99m in 50 (77%) of 65 patients with > or = 10 leukocytes/mm3 but in none of five patients with < 10 leukocytes/mm3 (p < 0.01). The findings in these five patients were consistent with colonization of the urinary tract rather than infection. For urine specimens obtained by catheter, we believe that urinary tract infection is best defined by both a leukocyte count > or 10/mm3 and a CFU count > or = 50,000/ml. This definition almost always discriminates among true urinary tract infection, bacteriuria resulting from contamination of the urine specimen, and asymptomatic bacteriuria.

Bacteriuria↗
PubMed1994

Technetium-99m hexamethylpropyleneamine-oxime-labeled leukocyte scintigraphy in inflammatory bowel disease in children.

Technetium Tc 99m-labeled hexamethylpropyleneamine-oxime (Tc-HMPAO) scintigraphy has been evaluated in adults with inflammatory bowel diseases and has shown promising ability to define intensity and extent of disease. To evaluate the method's utility in children, we studied 27 pediatric patients-23 with inflammatory bowel diseases and 4 control subjects without abdominal inflammation. Autologous leukocytes labeled with Tc-HMPAO were reinjected into each patient and serial scans were obtained up to 4 hours later. None of the control subjects had any uptake of Tc-HMPAO by the bowel. Disease localization as defined by the scan correlated well with that visualized in surgical specimens from five patients, at endoscopy in three patients, with barium studies of two patients, and with computed tomography scanning of the abdomen in one patient. A "scan score" was calculated by comparing uptake of tracer in five bowel segments with iliac crest bone marrow activity. Scan score correlated much better with clinical disease activity (correlation coefficient = 0.62) than did the erythrocyte sedimentation rate (correlation coefficient = 0.24). Scintigraphy with Tc-HMPAO appears to be useful in evaluation of disease localization and intensity in children with inflammatory bowel disease.

Adolescent↗
PubMed1994

Detection of inflammatory bowel disease in pediatric patients with technetium-99m-HMPAO-labeled leukocytes.

UNLABELLED: Technetium-99m-HMPAO-labeled leukocyte imaging is now an accepted technique in the assessment of adult patients with inflammatory bowel disease (IBD), but its role in pediatric patients has not been studied. METHODS: We evaluated the efficacy of 99mTc-HMPAO-labeled leukocyte imaging in 21 children. We studied 16 children with active IBD (4 ulcerative colitis, 10 Crohn's disease, 1 indeterminate colitis, 1 C-difficile) and 5 controls. RESULTS: The sensitivity and specificity for active bowel inflammation were excellent. The intensity of uptake noted in most patients rendered image interpretation easy and straightforward. The inclusion of a tail on detector (TOD) view and anterior standing view of the abdomen is important. All patients with ulcerative colitis showed rectosigmoid disease and no small bowel activity, whereas, all patients with Crohn's disease showed discontinuous uptake and often small bowel activity. It was therefore possible to differentiate ulcerative colitis from Crohn's disease on the basis of location and distribution. CONCLUSION: The 99mTc-HMPAO-labeled leukocyte scan is an excellent technique for the detection, localization and characterization of IBD in children.

Child↗
PubMed1993

Intra- and interobserver variability in interpretation of DMSA scans using a set of standardized criteria.

A set of criteria was developed to standardize assessment of DMSA renal scintigraphy which were performed to evaluate children for acute pyelonephritis and renal scarring. This study was undertaken to assess intra- and interobserver variability in the interpretation of DMSA renal scintigraphy using these criteria. Renal contours and parenchyma were assessed in three zones. Contours were assessed as normal or abnormal and parenchymal defects were evaluated in terms of character, shape and degree in three regions (upper and lower pole and midzone). Two nuclear medicine physicians blindly reviewed 57 DMSA scintigraphy on two occasions each. Disagreement of each observer's evaluation of the same scintigraphy on two different occasions was described as intraobserver variability, and the comparison between readings by each of the two observers was described as interobserver variability. High levels of intra- (95.9% and 90.6% respectively, p < 0.05) and interobserver agreement (84.4%, p < 0.05) were demonstrated. There were minor differences in inconsistencies between the two kidneys or different kidney zones. We conclude that standardization of criteria resulted in higher intra- and interobserver consistency in interpretation of DMSA scintigraphy.

Acute Disease↗
PubMed1991

Chromosome recombination and defective genome segregation induced in Chinese hamster cells by the topoisomerase II inhibitor VM-26.

We found that 4'-demethylepipodophyllotoxinthenylidene-beta-D-glucoside (VM-26; Teniposide), which specifically inhibits the enzyme DNA topoisomerase II, induces the formation of quadriradial chromosomes in Chinese hamster ovary cells. VM-26 traps topoisomerase II molecules when they are covalently integrated into DNA during their reaction. Quadriradial chromosomes are formed by reciprocal exchange of double-stranded DNA between single chromatids of two different chromosomes. Using synchronised cells, we found that they were formed after a single replication cycle in the presence of VM-26 at a low concentration (0.008 micro M), which does not affect DNA replication, and occurred in 50% of the mitotic cells at a concentration of 0.16 micro M. They were also formed when VM-26 was present for only 1.5 h before mitosis, after the completion of S-phase DNA replication. Chromatids bearing a translocated segment of another chromatid, which were derived from recombined chromosomes, were observed in late metaphase cells. Segregation of the daughter genomes was defective in many mitotic cells, probably because chromatids with two or no centromeres and kinetochores, formed from chromosomes recombined between their centromeres, could not be segregated. In the light of evidence that topoisomerase II molecules covalently integrated in DNA are trapped and therefore more abundant in the presence of VM-26, and that this enzyme can effect recombination of double-stranded DNA in vitro, we interpret these observations as evidence that topoisomerase II can mediate chromosome recombination in vivo.

Animals↗
PubMed1991

Phantom kidney: a CT correlation.

The phantom kidney is a "kidney-like" apparition which may be seen in dynamic renal scintigraphy typically in post-nephrectomy patients or in patients with unilateral renal agenesis. We report a case of a phantom kidney demonstrated in the angiographic phase of renal scintigraphy with 99mTc-dimercaptosuccinic acid (99mTc-DMSA) in a patient who was nephrectomized 14 years previously. After comparison with the CT images, we conclude that our patient's finding was caused by an increased mesenteric vascularity, possibly postprandial. Several conditions which may cause the phantom kidney effect, have been reported, but increased mesenteric vascularity seems to be the most common cause.

Adult↗
PubMed1991

De novo mania among elderly people.

De novo mania is defined as the occurrence of a first manic episode in a patient with no history of mood disorder, after exclusion of organic etiologies. Although it is believed to be rare in elderly populations, the authors nonetheless report 6 cases encountered over a 2-year period. The literature regarding mania among elderly people is reviewed, and the authors formulate their recommendations in view of more frequent recognition and better management of these patients.

Aged↗
PubMed1991

A comparison of the renal effects (ERPF, GFR, and FF) of FK 506 and cyclosporine in patients with liver transplantation.

1. The mean "cost" in milliliters per minute of ESLD alone, prior to transplantation, was 35% + 23% (1 SD). In GFR it was 15%. 2. The additional burden of CyA + OLT increases the loss in ERPF an additional 18%; in GFR, it increases loss another 10%. Thus, the total loss in CyA-treated patients was 53% and 25%, respectively. 3. The decrease imposed by FK 506 + OLT on ERPF was only 7%, with no decrease in GFR. 4. Therefore, from the renal point of view, FK 506 would appear to be the superior drug. 5. The large error around mean values underlines the desirability of performing these tests on the individual patient rather than on information from groups, since many values fall near the threshold of the azotemic range (ERPF approximately 175 mL/min). 6. As renal mass was compromised, ie, fall in the ERPF, the GFR increased relatively, ie, the renal filtering membrane became more permeable and the FFs gradually increased. 7. The loss of renal function was significantly less in OLT patients on FK 506 than CyA. However, the greatest loss in expected renal function was due to the basic ESLD itself.

Adult↗