PubMed Health⌕ Search

Biomedical subjects

S Zaidi

Publications and source records attributed to S Zaidi.

At least 19 recordsLinked to original sources
PubMed2004

Bone mineral assessment by dual energy X-ray absorptiometry in children with inflammatory bowel disease: evaluation by age or bone area.

BACKGROUND: Abnormal linear growth and deficient bone mineral acquisition may coexist in children with inflammatory bowel disease (IBD). Traditionally, bone mineral assessment by dual energy x-ray absorptiometry (DXA) involves comparison to age- and gender-matched reference ranges, and these studies in children with IBD show a high prevalence of osteopenia. AIMS: To compare the prevalence of osteopenia using two methods of interpretation; one adjusted for age and gender and the other adjusted for bone size and gender. PATIENTS: Forty-seven patients with Crohn disease (CD) and 26 patients with ulcerative colitis (UC) with a median age of 13.5 years (range, 5.5-18.2 years) were evaluated. METHODS: Lumbar spine (LS) and total body (TB) bone mineral content (BMC) were measured by DXA and converted to bone mineral density (BMD, g/cm) corresponding to BMC divided by the bone area. Age and gender-matched BMD standard deviation scores (SDS) were based on reference data providing age- and gender-matched BMC and bone area. These data also allowed calculation of percentage of predicted bone area for age and gender (ppBone Area) and percentage of predicted BMC for Bone Area (ppBMC). RESULTS: Patients with CD were shorter than those with UC (median height, SDS, -0.9 v 0, P < 0.05). Median ppBone Area for LS and TB for the whole group was 85% (10th centile, 68; 90th centile 99) and 81% (10th centile 66; 90th centile, 97), respectively. The ppBone Area at both sites was directly related to height SDS and BMI SDS (r > 0.5; P < 0.005). Median BMD SDS for LS and TB was -1.6 (10th centile -3.6; 90th centile, -0.2) and -0.9 (10th centile, -2.4; 90th centile, 0.4), respectively. Median ppBMC for LS and TB was 98% (10th centile, 84%; 90th centile, 113%) and 101% (10th centile 94%; 90th centile, 107%), respectively. The ppBMC showed no relationship to ppBone Area (r = 0.1, NS). Failure to account for bone area led to a label of moderate or severe osteopenia in 65% of cases. After adjustment for bone area, the proportion of children with osteopenia fell to 22%. CONCLUSIONS: The data suggest that children with IBD often have small bones for age because they have growth retardation. When DXA data are interpreted with adjustment for bone size, most children were found to have adequate bone mass. Correct interpretation of DXA is important for identifying children who may be at a real risk of osteoporosis.

Absorptiometry, Photon↗
PubMed1999

Endoscopic ultrasound for diagnosis and staging of pancreatic tumors.

Endoscopic ultrasound (EUS) is proving to be a useful tool for evaluation of clinically suspected pancreatic masses unsatisfactorily evaluated by other means of imaging. We reviewed the records of 19 patients who had CT and EUS performed for clinically suspected pancreatic masses. Each patient had subsequent surgical exploration. Nineteen patients (11 females and 8 males) presenting with symptoms (11 with obstructive jaundice, 6 with abdominal pain and weight loss) or incidental CT findings suspicious for pancreatic carcinoma underwent EUS for further pancreatic evaluation. All of these patients had exploratory laparotomies, with 13 pancreaticoduodenectomies, 3 distal pancreatectomies and splenectomies, 1 bypass procedure, 1 open pancreatic and hepatic biopsy showing metastatic disease, and 1 open exploration with negative fine-needle aspiration biopsy. EUS correctly identified pancreatic neoplasms in 17 of 19 cases, with two false positives. The tumors included 15 adenocarcinomas, 1 microcystic adenoma, and 1 lymphoma. Node status was correctly predicted in 9 of 12 specimens. Nine of 12 tumors had accurate tumor staging by EUS. Absence of vascular invasion was accurately predicted in 13 of 14 cases. Two patients had metastatic disease discovered at laparotomy. All 19 patients had preoperative abdominal CT scans, with six of these negative for pancreatic masses. EUS is more sensitive than CT in detecting pancreatic masses and is more accurate than CT in locally staging pancreatic tumors. This higher sensitivity is important because those patients with earlier stage tumors are the most likely to benefit from resection.

Adenocarcinoma↗
PubMed1997

Radial scanning and linear array endosonography for staging pancreatic cancer: a prospective randomized comparison.

BACKGROUND: Endoscopic ultrasound (EUS) is known to be accurate for staging pancreatic cancer. Little data exist to determine if linear array or radial scanning EUS is superior for staging pancreatic cancer. This prospective comparison was undertaken to assess the accuracy of linear array and radial scanning EUS for staging pancreatic cancer. METHODS: Patients with pancreatic cancer referred for EUS staging were randomized to linear array or radial scanning EUS. Staging accuracy for each was determined by comparison to surgical pathology in those patients going to surgery. RESULTS: Seventy-nine patients with pancreatic cancer were enrolled and 33 had surgical resection. Of these, 17 patients were randomized to linear array and 16 to radial scanning EUS. The remaining 46 patients did not have surgery because of comorbid illness or clinically unresectable disease. EUS staging accuracy for linear array was 94% (16 of 17) for T and 71% (12 of 17) for N staging, whereas radial scanning was 88% (14 of 16) for T and 75% (12 of 16) for N staging. For predicting vascular invasion, radial scanning was 100% accurate (16 of 16) while linear array was 94% (16 of 17) accurate. There was one false-negative assessment of invasion using linear array EUS. CONCLUSION: Overall, both EUS designs appear equivalent for staging pancreatic cancer and assessing vascular invasion. In view of our findings and the capability for ultrasound-directed fine-needle aspiration with linear array EUS, this instrument may be the preferred choice for evaluating pancreatic masses.

Adenocarcinoma↗
PubMed1996

Stent-induced pancreatic ductal and parenchymal changes: correlation of endoscopic ultrasound with ERCP.

BACKGROUND: Polyethylene pancreatic duct stents induce morphologic changes of the pancreatic duct in the majority of patients. This study was undertaken to determine if parenchymal abnormalities are present in patients undergoing short-term pancreatic duct stenting and to correlate these findings with the pancreatogram obtained at stent removal. METHODS: Twenty-five patients underwent pancreatic duct stenting and had an endoscopic ultrasound evaluation of the pancreas at stent removal. The pancreatograms were evaluated at stent removal for ductal irregularity, narrowing, and side branch changes. Endoscopic ultrasound was used to assess for differences in the echo characteristics of the pancreatic parenchyma around the stent compared with the rest of the gland. RESULTS: Of the 16 patients evaluated by ERCP at stent removal, 9 (56%) had 1 or more new ductographic changes. Endoscopic ultrasound identified parenchymal changes in the stented region in 17 of 25 patients (68%). Four patients who had parenchymal changes in the stented region on endoscopic ultrasound at stent removal had a follow-up study at a mean time of 16 months. Two patients had (new) changes suggestive of focal chronic pancreatitis in the stented region. CONCLUSION: Short-term pancreatic duct stenting induced both ductal and parenchymal changes in more than 50% of patients. Chronic pancreatitis may be a consequence of pancreatic duct stenting.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1996

Discovering asymptomatic biochemical abnormalities on a Baltimore internal medicine service.

To assess the frequency of abnormalities that could be discovered through biochemical profile screening on patients admitted to a city hospital internal medicine ward service, we conducted a prospective cross-sectional chart and laboratory review. All unassigned patients admitted to the general medicine service during 1- to 2-month period in late 1993 and the spring of 1994 were eligible. The main outcome measures were frequency of abnormal test results and identification of significance. Admitted patients (N = 222) were evaluated with a 24-panel biochemical profile. Of 5,328 tests, 29% were outside the standard reference range. Of 3,851 tests classified as screening, 1,049 (27%) were outside the reference range. Of overall screening tests, 741 (19%) were judged potentially important by the predetermined criteria. The prevalence did not differ significantly when analyzed by age, race, gender, or history of substance abuse. Our experience indicates that asymptomatic biochemical abnormalities are common in patients admitted to a city hospital medical service and that admission biochemical screening is an effective method of identifying potential comorbidity. Further studies are needed to assess the impact of this approach.

Adolescent↗
PubMed1995

Experience with a catheter-based ultrasound probe in the bile duct and pancreas.

BACKGROUND AND STUDY AIMS: Complete examination of the biliary tree and pancreatic duct may be difficult or unsuccessful using conventional imaging instruments. The purpose of this study was to evaluate the cannulation success rate, clinical utility, and safety of a new catheter-based ultrasound probe (CBUSP) used in the biliary tree and pancreas. PATIENTS AND METHODS: The probes used in this study are manufactured by Microvasive (Watertown, MA, U.S.A.) and were 6.2 Fr in diameter, operated at 12.5 MHz. Thirty-six patients (11 with malignant bile-duct strictures, 12 with benign bile-duct strictures, two with bile duct stones, three with pancreatic duct strictures, one with a pancreatic cyst, one with pancreas divisum, three with sphincter of Oddi dysfunction, and three normal) underwent examination with a CBUSP. RESULTS: Cannulation was successful in all 36 patients. The hepatic artery and portal vein could be visualized with the probe in the proximal bile duct in 81% and 94% of the cases, respectively. The portal vein could not be adequately visualized in any patients when the probe was in the distal bile duct. The mean thickness of the normal bile duct wall was 0.17 cm, and the mean wall thicknesses proximal to a benign and malignant stricture were 0.16 and 0.17 cm, respectively. The mean thicknesses of benign and malignant biliary strictures were 0.32 cm and 0.31 cm, respectively (not significant). Eight of 12 benign biliary strictures (67%) and five of 11 malignant strictures (45%) were symmetrical. However, no obvious differences could be identified between benign and malignant biliary strictures. There were no catheter related complications. CONCLUSIONS: Further catheter modifications are needed, but it appears to be feasible to assess vascular invasion in cholangiocarcinoma and to characterize biliary strictures in a way that may be able to influence therapy options in some patients. The currently available CBUSP cannot distinguish between benign and malignant strictures. However, with technical modifications, this may be possible in the future. The clinical usefulness of CBUSP in the pancreas awaits further investigation, but pancreatic imaging is feasible.

Adult↗
PubMed1995

Endoscopic ultrasonography of the pancreas.

The pancreas is the most technically demanding area to image with EUS. This technique, however, has found a clinical niche in evaluating patients with pancreatic cancer to determine resectability and likely will play a prominent role in the future in diagnosis through ultrasonographically directed FNA. Its role in localization of neuroendocrine tumors is established as long as preoperative localization is important in management. It is unlikely that a competing technology will develop in the near future with resolution the same or better than EUS. The role of EUS in the evaluation of early chronic pancreatitis is still under investigation, but it is likely that it can play a role adjunctive to ERCP. If FNA can be demonstrated to be safe and the interpretation of the cytology is accurate, then EUS could play an important role in this area. In the future, EUS may be used to acutely aspirate pancreatic pseudocysts and potentially could be useful in differentiating pseudocysts amenable to endoscopic drainage versus those that would be managed best by percutaneous or surgical drainage. With some design modifications, it may be feasible in the future to use ultrasonographic guidance to puncture pseudocysts and then place nasocystic drains or internal stents. These areas will need further investigation and further technological development.

Biopsy, Needle↗
PubMed1993

Malnutrition in Iraqi children following the Gulf War: results of a national survey.

The community-based Iraq Infant and Child Mortality and Nutrition Survey was designed to estimate mortality and nutritional status of Iraqi infants and children under five years of age after the Gulf conflict of 1991. This article presents results from a nationwide nutritional survey conducted between August 25 and September 5, 1991. A random multistage cluster sample was selected, including a subsample of 2676 children in the anthropometric analysis. The percentage below -2 standard deviations was 21.8% for height-for-age, 11.9% for weight-for-age, and 3.4% for weight-for-height. It is possible that the observed prevalence of wasting was an underestimate, resulting from a survivor bias. This observation suggests that cross-sectional nutritional surveys may not be the most appropriate method for assessing the effect of the Gulf conflict on the nutritional status of children in Iraq. Longitudinal information on child mortality and nutritional status would be more useful in predicting the likelihood of famine.

Body Height↗
PubMed1992

Aneurysmal bone cyst of the hyoid.

Aneurysmal bone cyst is a rare lesion usually of the long bones, well documented in the literature. It is a cystic, osteolytic vascular tumour, replete with giant cells and fibrous septa, yet devoid of endothelial lining. It has been reported in the larynx and maxillary sinus. This appears to be the first report of an aneurysmal bone cyst occurring in the hyoid bone.

Adolescent↗
PubMed1991

Famotidine relieves symptoms of gastroesophageal reflux disease and heals erosions and ulcerations. Results of a multicenter, placebo-controlled, dose-ranging study. USA Merck Gastroesophageal Reflux Disease Study Group.

We conducted a double-blind, placebo-controlled, multicenter trial comparing the efficacy of famotidine 40 mg administered at bedtime (HS), 20 mg given twice daily (BID), and placebo to relieve heartburn and to heal endoscopically documented esophageal erosions or ulcerations. A total of 338 patients were randomized: 135 to receive famotidine 40 mg HS, 137 to receive famotidine 20 mg BID, and 66 to receive placebo. In the group given famotidine 20 mg BID, there was a significantly greater proportion of patients with complete relief of daytime heartburn, and both famotidine groups demonstrated statistically significant advantages over placebo in global scores or by successful outcome. Antacid consumption was significantly reduced in the group given famotidine 20 mg BID as compared with placebo. Both famotidine regimens resulted in a significantly greater proportion of patients with complete endoscopic healing than placebo, with the BID dosing being numerically superior to the 40-mg HS dose.

Adult↗
PubMed1990

Detection of HIV-antibody evaluation of four commercially available enzyme immunoassays.

We evaluated 550 serum samples with four commercially available enzyme immunoassays and Western Blot was used as the confirmatory test for antibodies against human immunodeficiency virus (HIV). The Wellcozyme (Wellcome), Flow HIV-TEK G, and Behring test kits identified all 50 Western Blot positive samples correctly, whereas DuPont failed to detect one sample. None of the kit was able to pickup one sample that showed a faint P24 band on Western Blot strip. The frequency of false positive reaction in the 500 negative serum samples were Wellcome 0%, Behring and DuPont 0.2% and Flow HIV-TEK 0.4%.

AIDS Serodiagnosis↗
PubMed1990

A study of financial resources devoted to research on health problems of developing countries.

The Commission on Health Research for Development is an independent, international commission composed of 12 leaders from the fields of health research, social science research and development policy. Chaired by John Evans, the other Commissioners are Gelia Castillo, vice-chair, F. H. Abed, Sune Bergstrom, Doris Calloway, Esmat Ezzat, Demissie Habte, Walter Kamba, Adetokumbo Lucas, Adolfo Martinez-Palomo, Saburo Okita and V. Ramalingaswami. The Commission began its work in November 1987, charged with analysing the strengths, weaknesses and gaps in current research on health problems of developing countries, and making proposals and promoting action for improvement. The Commission is sponsored by a variety of foundations, bilateral donor agencies, and international organizations. The Commission's report was published in the spring of 1990. As part of the work of the Commission Secretariat, we have undertaken a study of financial resources devoted to research on the health problems of developing countries. The study which began in May 1988 has three objectives: (i) To describe the current pattern of funding for research on the health problems of developing countries. (ii) To provide a baseline against which future trends and/or new programmes can be measured. (iii) To explore the possibility of an ongoing information system on research on health problems of developing countries.

Developing Countries↗