Search PubMed⌕ Search

Biomedical subjects

J Ahmed

Publications and source records attributed to J Ahmed.

At least 55 records · Page 3Linked to original sources
PubMed1997

Adaptation and validation of a portable steam sterilizer for processing intrauterine device insertion instruments and supplies in low-resource settings.

BACKGROUND: Difficulties with adequately processing intrauterine device (IUD) insertion instruments and supplies have led to use of potentially contaminated items, compromising the quality and safety of IUD insertion services in Bangladesh. A sterilization process for IUD insertion instruments and supplies by using a commercially available portable steam sterilizer was developed and validated. METHODS: Racks provided with the sterilizer were used during sterilization of wrapped supplies (gloves and cotton balls). Metal compartments to hold insertion instruments were built to fit into the sterilizer. After sterilization, supplies were transported to rural service sites in plastic bags, whereas instruments remained in the sterilizer, which was transported in a carrying case. To validate the sterilizer, laboratory testing was conducted by using chemical and biologic indicators for steam sterilization and field testing in Bangladesh with chemical indicators. RESULTS: Results indicated that sterilization cycles were effective in achieving sterility of IUD insertion supplies and instruments at sterility assurance levels of 10(-5) and 10(-6), respectively. CONCLUSIONS: Use of this sterilizer for IUD insertion supplies and instruments will improve the quality of service delivery in the Bangladesh family-planning program and has application for use in many other low-resource settings.

Bangladesh↗
PubMed1997

Respiratory isolation of patients with suspected pulmonary tuberculosis in an inner-city hospital.

OBJECTIVE: To identify clinical factors that predict which patients presenting to the ED with pneumonia will require respiratory isolation for suspected tuberculosis and to evaluate a protocol for rapid identification of patients at risk for pulmonary tuberculosis (PTB). METHODS: To identify potential clinical indicators of PTB, a case-control study was performed using patients admitted to an urban teaching hospital with the ED diagnosis of pneumonia (derivation sample). These predictors were then evaluated in a separate prospective observational study of 103 patients admitted to the same institution from July 1994 to February 1995. Adult patients with the admitting diagnosis of pneumonia were admitted to a respiratory isolation bed if they met 1 of the following criteria: 1) HIV-positive or unknown HIV status with a history of injection drug use; 2) chest x-ray consistent with PTB; or 3) pneumonia with 1 of the following: PPD conversion within 2 years, recent exposure to PTB, previous PTB, or hemoptysis. Patients who did not meet isolation criteria were admitted to the medical ward and had a PPD and anergy panel placed. Those who were anergic or PPD-positive were transferred to respiratory isolation. RESULTS: Predictor variables identified during the first study phase were incorporated into the isolation guidelines noted above. Only 36 of 50 (72%) PTB patients were admitted to an isolation bed during this phase. During the second phase, 103 patients were admitted with the ED diagnosis of pneumonia-rule out PTB; 22 patients (22%) were culture-confirmed positive for PTB. The guidelines predicted PTB as follows: sensitivity, 0.96 (95% CI, 0.88-1.0); specificity, 0.14 (95% CI, 0.08-0.24); positive predictive value, 0.23 (95% CI, 0.17-0.35); and negative predictive value, 0.92 (95% CI, 0.77-1.0). The 1 patient who was not isolated was found to be anergic after 48 hours and subsequently isolated. CONCLUSION: Respiratory isolation guidelines for patients admitted from the ED with pneumonia were developed and validated. These guidelines provide satisfactory guidance for isolation of patients at risk for PTB in a high-PTB-prevalence population.

Adult↗
PubMed1996

Asymptomatic coronary artery disease detection: update 1996. A screening protocol using 16-lead high-resolution ECG, ultrafast CT, exercise testing, and radionuclear imaging.

The authors have proposed a new four-step screening algorithm to detect asymptomatic coronary artery disease (CAD) in flight school candidates, cadets, and rated flyers of the Unites States Air Force (USAF). In step 1, the USAF Armstrong Laboratory (USAF/AL) risk profile and improved 16-lead high-resolution electrocardiogram/vectorcardiogram will be recorded at baseline. On routine follow-up evaluations, quantitative serial comparisons will be performed by the method of Kornreich. In step 2, beginning with flight school candidates and cadets, all three groups will be studied by the ultrafast computed tomograph (CT) protocol. Those candidates positive for coronary calcium will be studied by coronary angiography and ventriculography, and their eligibility for continued rated flight status will be determined by present criteria. In step 3, those candidates negative for coronary calcium by ultrafast CT will then be screened by the newly defined and improved high-sensitivity treadmill exercise test criteria. In step 4, candidates with a positive treadmill exercise test result, or who are also found in the upper quintile of the USAF/AL risk profile, wild also have exercise nuclear wall motion studies and perfusion scans. If these are abnormal and suggestive of myocardial ischemia, this subset will also be studied by heart catheterization and coronary angiography, and their eligibility for continued rated flight status will be determined by present criteria. The incidence of coronary calcium/no calcium for each degree of stenosis in the 6,000 flyers in each quintile was used to develop the following projections: (1) that more than 3 of 4 rated flyers with unsuspected CAD, and (2) more than 9 of 10 with severe flow-limiting CAD can be identified by these upgraded screening procedures. Evidence is herein presented that these enhancements will result in a major (5-8-fold) increase in case finding of this disease. Based on the estimate of four lost high-performance aircrafts per year from sudden incapacitation of the pilot due to CAD, when this four-step screen is fully operational, it can be expected to reduce the $80 million annual losses to the United States government from CAD by 85%, a savings of $68 million per year.

Adult↗
PubMed1996

The reference value of erythrocyte sedimentation rate for differential diagnosis of rheumatic fever among Bangladeshi children.

The aim of the present study is to determine the reference value of erythrocyte sedimentation rate for differential diagnosis of rheumatic fever in the National Center for Control of Rheumatic Fever and Heart Diseases, Dhaka, Bangladesh among patients with signs and symptoms which may be related to acute rheumatic fever. All medical records for the patients aged 5 to 20 years who attended the outpatient department of the hospital between July, 1994 and November, 1995 were reviewed. Fifty-three of 337 such patients had acute rheumatic fever defined by the updated Jones criteria. The performance of erythrocyte sedimentation rate test was evaluated by sensitivity, specificity, positive predictive value, and receiver operating characteristic curve. The findings of this study suggest that the lower limit for a positive test should be considered at 30 mm (Westergren 1 h) in this hospital.

Adolescent↗
PubMed1995

Critical evaluation of computerised x ray planimetry for the measurement of lung volumes.

BACKGROUND: Computerised x-ray planimetry has been advocated as an alternative to body plethysmography and helium dilution for measuring static lung volumes. The accuracy and reproducibility of this method has been assessed in comparison with these standard methods. METHODS: Plethysmographic and planimetric measurements of total lung capacity (TLC) and functional residual capacity (FRC) were made in 10 normal subjects and in 12 patients with chronic obstructive pulmonary disease (COPD), with additional helium dilution measurements in the latter 12 patients. RESULTS: Mean lung volumes (TLC and FRC) for groups of subjects measured by planimetry and by plethysmography were similar in both groups and larger than the helium dilution measurement in patients with COPD. Intraindividual agreement between planimetry and plethysmography was poor, however, with a wide confidence interval (-2.2 to +2.31). The planimeter did not measure reliably changes in volume from TLC to FRC in individuals. CONCLUSIONS: Mean lung volumes measured by planimetry in a group of patients probably reflect a regression to the mean of the computer algorithm rather than accurate TLC estimation. The technique is not yet robust enough to replace the established techniques of helium dilution or plethysmography.

Adult↗
PubMed1995

Prevalence of streptococcal sorethroat in the school children of Dhaka.

Beta Haemolytic Streptococcal (BHS) infections and their sequelae Rheumatic Fever (RF) and Glomerulonephritis (GN) have a world wide distribution and so pose an important health problem. Reports show that there is considerable variation in the number of isolations from different groups. Present study intended to find out the health status of the school children in relation to streptococcal throat infection, in Dhaka Cantonment. It was a cross sectional, observational study. During one year period total six hundred and one (601) children were examined from one school of Dhaka Cantonment. Prevalence of streptococcus was found to be 22% among the study population with highest rate (67%) for group-G among BHS positive cases. True streptococcal infection was found in 8.7% cases & 2.2% cases were true GABHS positive cases. GABHS was significantly higher in large size families. Females and children from lower socioeconomic group were at higher risk. Females and children of large families may require special attention regarding prevention of streptococcal infection and RF/RHD prevention programme.

Adolescent↗
PubMed1994

The oxygen distribution in the prelaminar optic nerve head of the cat.

Oxygen-sensitive microelectrodes were used to measure oxygen profiles from the prelaminar region of the cat optic nerve head. From the profiles, the oxygen distribution of this tissue was determined. Changes in oxygen levels in response to flicker stimulation were obtained. Also, the regulatory ability of this tissue was assessed by acutely increasing IOP and by presenting the cat with periods of hyperoxia. The cells in the optic nerve head were found to exist in the same oxygen environment as cells of the inner retina. Oxygen tensions usually varied between 0 and 40 mmHg, with the mean being between 10 and 20 mmHg. There was no difference in oxygen levels between central and peripheral parts of the optic nerve head, nor was there a difference as a function of depth. Different levels of light adaptation of the retina had no effect on oxygen levels in the optic nerve head, but flicker stimulation of the retina resulted in decreases in tissue oxygen tension. A small number of experiments in which the intraocular pressure was raised showed that oxygen levels in the optic nerve head were not drastically altered during acute decreases in perfusion pressure. Based on the size of changes in tissue oxygen tensions during hyperoxia, it appeared that blood vessels in the optic nerve head constricted in response to systemic hyperoxia.

Adaptation, Ocular↗
PubMed1994

Acinetobacter calcoaceticus anitratus outbreak in the intensive care unit traced to a peak flow meter.

BACKGROUND: A cluster of seven cases of Acinetobacter caleoaceticus anitratus in a community teaching hospital intensive care unit was discovered (the seventh case was located in a step-down unit next to an infected patient recently transferred from the intensive care unit.) METHODS: An outbreak investigation, including detailed epidemiologic, clinical, and laboratory investigation, was performed. RESULTS: A single strain of A. calcoaceticus anitratus was responsible for infection in all seven patients. All patients had tracheostomies, were in respiratory failure, and were ventilator dependent. Patients ranged in age from 27 to 81 years. No common causative variable or explanatory findings were present except that the same peak flow meter (manual weaning criteria machine) was used to facilitate weaning all seven patients from mechanical ventilation. Culture of the mouthpiece isolated a A. calcoaceticus anitratus strain with the identical susceptibility pattern and biochemical profile as that from the infected patients. CONCLUSION: A. calcoaceticus anitratus was transmitted by a peak flow meter nosocomially to seven patients receiving mechanical ventilation. Disposable mouthpieces were introduced to prevent cross-contamination. A 2% glutaraldehyde solution was used to disinfect the machine between uses. No further outbreaks of A. calcoaceticus anitratus pneumonia were identified during 3 years of follow-up.

Acinetobacter Infections↗
PubMed1994

ECG myocardial infarct size: a gender-, age-, race-insensitive 12-segment multiple regression model. I: Retrospective learning set of 100 pathoanatomic infarcts and 229 normal control subjects.

In this early study of ongoing work with multiple regression modeling for mapping myocardial infarct (MI) into 12 left ventricular (LV) segments, promising results have been presented using electrocardiographic (ECG) QRS variables that are gender, age, and race insensitive (GARI), the GARI-QRS 12-segment multiple regression model. These include Q, R, and S duration, expressed as percentage total QRS duration, and R/Q duration, R/Q amplitude, R/S duration, and R/S amplitude variables. For version I, building 12 regression models using 68 single and 32 multiple MIs, the GARI-QRS variables correlated with pathoanatomic MI in each of 12 segments with r values ranging from .67 to .88. In version II of the model, using all MIs and 229 normal subjects, r = .73-.91. Version II predictions of MI in 12 LV segments for each subject were used to calculate the predicted total percentage LV infarct, which correlated well with that found at autopsy. The r values found were .81 for all single MIs, .73 for multiple MIs, and .80 for all MIs taken together. With refinements of the input ECG variables to include (1) improvement in the GARI-QRS variables, (2) adding a significant number of subjects with hypertrophies and conduction defects with and without MI to an expanded learning set, and (3) applying the enhanced 12-LV-segment regression models to a similar test set, it is to be expected that these regression models can be improved even further in such a way as to be applicable to general clinical populations using routine computerized ECG analysis programs.

Adult↗
PubMed1994

Paucibacillary leprosy patients treated with multidrug therapy four years experience (1988 to 1991) in Bangladesh.

Two hundred and fifty paucibacillary (PB) leprosy patients were treated with WHO recommended multidrug therapy (MDT) and followed up them for four years. The paucibacillary MDT regimen (PBR) was well accepted and tolerated by the patients. Clinical regression was attained in 60% patients after 6 doses of PBR. Reversal reaction occurred in 14% cases and relapse were found in 1.6% cases 18-24 months after completing the treatment. The incidence of reversal reaction was high in patients with more than 2 thickened nerve trunks associated with more than 5 patches.

Adolescent↗
PubMed1993

Disk shedding in the absence of a pigment epithelium in the lizard parietal eye.

The photoreceptors and pigment epithelia of vertebrate retinas rhythmically synthesize and degrade photosensitive membrane, but the origin of the signal to shed the outer segment tips remains unknown. The parietal eye of lizards contains cone-like photoreceptors but no pigment epithelium. Parietal eye photoreceptors synthesize new disk membrane in a manner similar to rods and cones and also shed their tips rhythmically. The shed material is then engulfed by lumenal macrophages. The signal to shed must originate in, or be transduced by, the photoreceptor.

Animals↗
PubMed1993

Does cold air affect exercise capacity and dyspnea in stable chronic obstructive pulmonary disease?

Cold air may worsen asthmatic bronchoconstriction but can lessen breathlessness in normal individuals. Patients with COPD sometimes report improvement in their dyspnea in cold weather. We examined the effect of breathing cold air on exercise tolerance and the perception of breathlessness in 19 patients with stable COPD (age [+/- SD], 63 +/- 6 years; FEV1, 0.99 +/- 0.28 L) in a randomized open study. Patients exercised on a cycle ergometer breathing either room or cold air (-13 degrees C), breathlessness being assessed by Borg scaling. Peak exercise performance improved when breathing cold air (mean +/- SE), 46 +/- 6 W compared with 37 +/- 7 W (p < 0.05) while end-exercise breathlessness fell from 4.6 +/- 0.4 compared with 4.1 +/- 0.5 (p < 0.05) when breathing cold air. End-exercise ETCO2 was higher breathing cold air (6.1 +/- 0.3 kPa compared with 5.5 +/- 0.3 kPa) (p < 0.005). There was no difference in breathlessness at equivalent levels of ventilation. Cold air reduces breathlessness in COPD, probably by inducing relative hypoventilation.

Aged↗
PubMed1993

Oxygen distribution in the macaque retina.

PURPOSE: Oxygen distribution was characterized in the macaque retina, which is more like the human retina than others studied previously. METHODS: Profiles of oxygen tension (PO2) as a function of distance were recorded in a parafoveal region about halfway between the fovea and optic disk, and from the fovea in one animal. A one-dimensional diffusion model was used to determine photoreceptor oxygen consumption (QO2). RESULTS: In the parafovea, the PO2 decreased as the electrode was withdrawn from the choroid toward the inner retina, reaching a minimum value during dark adaptation of about 9 mmHg at about 70% retinal depth, and then increasing more proximally. Approximately 90% of the oxygen requirement of the photoreceptors was supplied by the choroidal circulation and 10% by the retinal circulation. In light adaptation, there was a monotonic PO2 gradient from the choroid to the inner retina, indicating that all of the oxygen used by photoreceptors was supplied by the choroid. In the fovea, the choroid supplied almost all the oxygen in both dark and light adaptation, with a minor supply from the vitreous humor. Dark-adapted foveal oxygen consumption was lower than parafoveal oxygen consumption. Light reduced the oxygen consumption of the photoreceptors, in both regions studied, by 16-36%. CONCLUSIONS: The results show that oxygenation of the parafoveal monkey retina is similar to that previously observed in the cat area centralis. In the fovea, the oxygen distribution differs as expected considering the thinner retina and the absence of inner retinal neurons and retinal circulation.

Animals↗
PubMed1991

Oral rehydration therapy: a community trial comparing the acceptability of homemade sucrose and cereal-based solutions.

Sugar-based oral rehydration therapy (ORT) for diarrhoea is promoted in many countries of the world. One programme in Bangladesh has instructed more than 13 million mothers in the preparation of a sugar-salt solution in the home; despite very high rates of correct mixing and knowledge, subsequent application was found in only some 20% of all diarrhoea episodes. Since rice is far more available in rural homes (95%) than any type of sugar (30%) and rice gruel is a widely accepted food during illness, a field trial was conducted in three areas (total population, 68,345) to compare the acceptability and use of rice-based ORT with that of sugar-based ORT. Although the mothers unanimously agreed that the rice-based solutions "stopped" the diarrhoea more quickly, they used the sugar-based solutions twice as often (in 40% of severe watery episodes) as the rice-based solutions (in 18%), because the rice-ORT was much more time-consuming and difficult to prepare. The observed reduced utilization of home-made rice-ORT makes it a poor substitute for sugar-ORT at the community level in rural Bangladesh.

Adolescent↗
PubMed1989

Production and consumption of T cell growth factor by peripheral blood lymphocytes of cattle infected with Taenia saginata.

Calves were infected with 25,000 or 50,000 viable eggs of Taenia saginata. Larval numbers ranged between 2077 and 6005. During infection the animals developed leucocytosis, which was mainly due to lymphocytosis. An apparently positive correlation was observed between the lymphocytosis and the in vitro proliferative response of the lymphocytes to antigen prepared from proglottids. Maximal in vitro blast transformation of the cells stimulated with antigen occurred on Days 12 and 32 post-infection (p.i.). Specific antibodies to T. saginata were demonstrated on Day 14 p.i. At that time, the proliferative response of the cells paralleled the formation of specific antibodies, particularly of the IgG class. The stimulated cells produced a lymphokine showing interleukin 2 (IL 2)-like activity, since the addition of supernatant of such cells to IL 2-dependent concanavalin A (Con A)-blast cells supported the in vitro growth of the cells. In addition, peripheral blood lymphocytes (PBL) specific for T. saginata could be maintained in long-term cultures when they were cultured in medium containing supernatants of MLA-144 cell lines. The data presented in this study indicate that cells specific for T. saginata produced and consumed T cell growth factor (TCGF).

Animals↗
PubMed1989

The detection of glaucomatous visual field defects by oculo-kinetic perimetry: which points are best for screening?

Oculo-kinetic perimetry (OKP) uses the patient's ocular movements to position a test stimulus in the visual field. By virtue of its simplicity and low cost, this test could be useful in the screening of glaucoma. The general purpose OKP chart, however, which tests 100 points in the central 25 degrees field, is too time-consuming for this purpose, taking approximately 4-7 minutes per eye. Accordingly, this study was performed to identify the points most likely to detect patients with glaucoma. Fifty-one eyes with glaucomatous visual field defects and 51 non-glaucomatous eyes of age matched individuals were tested by conventional and oculo-kinetic perimetry. At least one of only six points were missed by 82.4% of glaucomatous eyes and by 9.8% of nonglaucomatous eyes. These results, although falling short of the ideal efficiency, are comparable with data published by other research groups using computerised equipment and suggest that, with further development, a specialised OKP chart testing only a small number of points might be valuable in screening for glaucoma.

Adult↗
PubMed1988

Teaching ORT to women: individually or in groups?

Programmes to promote the widespread use of oral rehydration therapy (ORT) for diarrhoea used a variety of methodologies to carry the message to mothers. The Bangladesh Rural Advancement Committee (BRAC) sent its health workers to individual households, and mothers were trained through a one-to-one approach. The cost of training a mother was 72 US cents. Recently, an alternative approach was tried. Instead of individually, mothers were trained in groups which halved the cost. Outcome indicators, such as usage, knowledge and safety of ORT solution, were looked at for each type of approach and were not found to be significantly different.

Bangladesh↗