Biomedical subjects
Publications and source records attributed to M Aslam.
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OBJECTIVES: The aim of the study was to compare a novel infrared optoelectronic system (Perometer) of limb volume measurement with water displacement and two indirect measurement techniques. DESIGN: A prospective experimental study. METHODS: In 10 healthy male volunteers (20 limbs) we compared limb volume measurements obtained by water displacement, infrared perometry, the disc model method and the frustrum method. In a further 17 patients with swollen limbs due to lymphatic (9 limbs) or venous (11 limbs) disease, perometry was compared to the disc model method and the frustrum method only. RESULTS: In normal limbs, mean +/- S.D. limb volume using water displacement was 1802 +/- 268 ml. Perometer values agreed almost exactly (1809 +/- 262 ml, r = 0.97, variation +/- 7% by limits of agreement) but both the disc (1923 +/- 306 ml, r = 0.90, variation +/- 14%) and frustrum (1905 +/- 372 ml, r = 0.72, variation +/- 28%) methods significantly overestimated limb volumes (p < 0.05 (ANOVA, Fisher's Least Significant Difference)). In diseased limbs perometer, disc method and frustrum method results were 2415 +/- 995 ml, 2494 +/- 969 ml, and 2413 +/- 870 ml representing variation of +/- 17% and +/- 23% for disc method and frustrum method respectively compared to perometry. CONCLUSIONS: Perometry is a novel, extremely accurate and easy method for assessing limb volume. It provides more accurate results than traditional indirect measurement of limb volume and potentially is a very useful clinical and research tool.
Nuclear medicine can provide useful data when monitoring the organ function of patients undergoing intensive care. Test procedures involve the administration of radiopharmaceuticals and external monitoring using gamma cameras or nuclear probes. The radiopharmaceuticals required may be given at lower doses than normally used in routine nuclear medicine imaging, are ideally available 24 h a day and are preferably administered via indwelling cannulae and giving sets. Three radiopharmaceuticals have been studied; a renal function agent, a hepatobiliary function agent and a product used for in vivo labelling of protein for lung permeability studies. Under conditions of storage, dilution and passage through giving sets (simulating conditions found during administration in the intensive care setting), some instability can be demonstrated in each product, which could result in the tests giving rise to wrong or misleading data. It is recommended that radiopharmaceuticals are not diluted excessively, and that where possible, parenterally-administered products are given by direct intravenous injection and not through giving sets.
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The effects on plasma electrolytes and related hormones were determined in non-acclimatized low lander males, exposed for 96 hours to an altitude of 4424 meters. Twenty healthy soldiers aged 18-34 years travelled by road from an altitude of 2303 meters to 4424 meters over a period of 10 hours. Plasma sodium levels (142.09 +/- 1.14 mmol/1) and aldosterone (16.61 +/- 5.70 ng/ml) decreased to 139.69 mmol/1 and 11.6 +/- 4.60 ug/ml respectively after 96 hours of acute exposure to high altitude (p < 0.05). The plasma potassium and chloride levels did not show significant change, while, plasma HCO3 decreased gradually from 21.06 +/- 1.38 mmol/1 to 18.55 +/- 0.82 mmol/1 after 96 hours exposure to this altitude (p < 0.01). The plasma ionized calcium and plasma phosphate concentration decreased from 1.32 +/- 0.11 mmol/1 and 1.58 +/- 1.3 mmol/1 to 1.20 +/- 0.05 mmol/1 and 1.47 +/- 0.99 mmol/1 respectively (p < 0.05). Plasma parathyroid hormone (PTH) level increased from 4.54 +/- 2.1 ng/ml to 11.19 +/- 4.31 ng/ml after 48 hours with subsequent decline to 2.52 +/- 1.7 ng/ml after 96 hours exposure to high altitude. It may be concluded that the process of acclimatization to sudden exposure to high altitude is characterised by fall in plasma aldosterone and PTH with subsequent decrease of related electrolytes.
Previous designs of isolated rat liver perfusion circuits used for toxicological investigations are often expensive, cumbersome, or traumatic in relation to hepatic biocompatibility following extended perfusion times. A new, miniaturized circuit that incorporates a novel design of organ bath, to maintain a buoyant preparation, and a high-efficiency miniaturized membrane tubing oxygenator is described. Livers from male Sprague-Dawley rats were perfused continuously for 6 hr in vitro using rat blood diluted to a perfusate hematocrit of 9.75 +/- 0.35% with Krebs-Henseleit buffer (KHB). Hepatic function was evaluated by measurement of perfusion pressure, flow rate, bile volume production, bile bilirubin content, hepatic oxygen uptake (HOU), bromosulphthalein (BSP) removal, hepatic enzyme activities, and electrolyte concentrations, and finally by histological examination. Perfusion pressure and flow rate remained stable at 8.7 +/- 1.7 mmHg and 1.92 +/- 0.06 mL min-1 g-1 liver, respectively. Bile volume production and HOU were maximal at 784 +/- 84 microL h-1 and 0.99 micromol/L min-1 g-1 respectively. Erythrocyte damage in the perfusate was evaluated by measurement of reduction in perfusate hematocrit from 9.75 +/- 0.35% to 9.27 +/- 0.24%, and increases in plasma free hemoglobin, which rose from 85.8 +/- 12.3 mg% to 650.1 +/- 53.3 mg% over the 6-hr perfusion period studied. Using bile volume production, hepatic oxygen uptake, and the liberation of plasma free hemoglobin as the most sensitive indices of adverse conditions, the new circuit was capable of supporting an isolated perfused rat liver for periods of up to 6 hr under close-to-physiological conditions.
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Synthesis of lactoferrin and casein by the bovine mammary gland was determined in an experimental model where lactation was maintained in one mammary half, while involution was induced in the contralateral half. Culture of explants with prolactin had no consistent effect on synthesis of casein or lactoferrin in tissue from either mammary half. Endotoxin and tumor necrosis factor-alpha generally decreased synthesis of casein and lactoferrin, suggesting that these inflammatory mediators are not directly responsible for increasing lactoferrin synthesis during mammary inflammation or involution. Synthesis of lactoferrin was increased and casein decreased in the involuting mammary half vs. the lactating half. These results suggest that local factors in the mammary gland play a role in the regulation of lactoferrin synthesis during involution.
This article reports the effect of coexposure to Indian chrysotile asbestos (5 mg/rat) and kerosene soot (5 mg/rat) on the pulmonary phase I and phase II drug-metabolizing enzymes 1, 4, 8, 16, 30, 90, and 150 days after a single intratracheal inoculation. Exposure to soot resulted in a significant induction of the pulmonary microsomal cytochrome P450 and the activity of dependent monooxygenase, benzo(a)pyrene (B[a]P) hydroxylase, and epoxide hydrase at all time intervals. On the other hand, the cytosolic glutathione S-transferase (GST) activity was induced at days 1, 4, 8, 16, and 30 after exposure, followed by inhibition in the enzyme activity. In contrast, chrysotile exposure depleted cytochrome P450, B[a]P hydroxylase, epoxide hydrase, and GST at initial stages, while all these parameters except GST were induced at later stages. However, coexposure to chrysotile and soot led to a significant inhibition in the cytochrome P450 levels, activities of B[a]P hydroxylase, epoxide hydrase, and GST at initial stages of exposure. At advanced stages, however, an additional increase in cytochrome P450, B[a]P hydroxylase, and epoxide hydrase but a decrease in GST was observed. These results clearly show that the intratracheal coexposure to high levels of asbestos and kerosene soot alters the metabolic activity of the lung, which is turn may retain toxins in the system for a longer period, resulting in adverse pathological disorders.
Proteins in mammary gland secretions, collected from Holstein cows during the dry period, were analyzed by preparative isoelectric focusing, followed by SDS-PAGE. Protein profiles changed throughout the dry period. Intact casein bands were present throughout the dry period, but in reduced proportions from d 7 after dry-off through d 7 prepartum. Breakdown fragments of casein were particularly apparent in secretions from d 7 to 21 of the dry period. A fragment of beta-CN (approximately 13 kDa) was identified in secretions collected on d -1 prior to dry-off through d 21 of the dry period. beta-Lactoglobulin generally focused in a limited number of fractions, but, in the sample at d 21 prepartum, beta-LG focused over a broad pH range. Lactoferrin was found in all fractions after isoelectric focusing, but specific degradation products of lactoferrin were apparent only at certain times during the dry period. This method is a valuable approach for separation of proteins from the complex mixtures found in mammary secretions during the dry period. A number of peptides identified by this method may be generated from breakdown of milk proteins in the mammary gland during the dry period and could have a role in the involuting gland.
Forty-eight multiparous Holstein cows were blocked according to month of parturition, age, and previous milk yield and arranged in a randomized complete block design to evaluate the effect of a naturally occurring sodium sesquicarbonate on DMI, milk yield, milk composition, milk value, and systemic acid-base status. Cows were assigned at parturition to diets containing sorghum silage, alfalfa hay, concentrate, and 0 or 1% naturally occurring sodium sesquicarbonate (DM basis); cows were fed these diets for 308 d postpartum. Blood was collected every 4 wk via jugular venipuncture for analysis of pH, HCO3, partial pressure of O2, and partial pressure of CO2. Sesquicarbonate exhibited alkalogenic properties by increasing blood HCO3, partial pressure of CO2, and total CO2 for the 308-d lactation. Buffer tended to increase DMI and increased milk protein throughout lactation. During 0 to 56 d postpartum, sodium sesquicarbonate did not affect milk yield or composition. In midlactation (56 to 252 d postpartum), buffer increased milk protein content only. During 252 to 308 d postpartum, milk fat and protein contents increased with buffer supplementation. Hence, the value of milk yielded daily was similar for all cows. Effects of dietary buffer on all variables were more pronounced during late lactation.
Calcium silicate has been considered as a possible replacement for asbestos due to its heat and fire resistance. We describe the cytotoxic and genotoxic potential of calcium silicate using peripheral human blood lymphocytes. Calcium silicates at concentrations of 10 and 100 micrograms/ml significantly increased the frequencies of chromosomal aberrations (CAs) and sister-chromatid exchanges (SCEs). The increases in CAs and SCEs were dose-dependent, though not linearly. A significant decrease in the proliferation rate index was observed with increased dose of calcium silicates. The induction of chromatid-type aberrations indicates that the clastogenic activity of calcium silicate is S-phase-dependent.
Four ruminally cannulated, lactating Holstein cows were assigned to a 4 x 4 Latin square to monitor effects of intraruminal NaHCO3 infusion on temporal changes in ruminal and systemic acid-base status and mineral metabolism. Twice daily from 2 to 4 h postfeeding, cows were infused with 0, 110, 220, or 330 g of NaHCO3 dissolved in 3.8 L of water. All cows had access to their TMR of sorghum silage and concentrate (35: 65, DM basis) for 2 h twice daily. Ruminal fluid, blood, and urine were collected at feeding and every 30 min postfeeding for 12 h on the last day of each 14-d period. Total urine volume also was measured during this interval. Infusion of buffer increased ruminal fluid buffering capacity transiently at 4.5 h postfeeding but otherwise did not markedly affect ruminal fluid acid-base status. Systemic acid-base status was unaffected by the buffer primarily because renal excretion of base successfully reduced systemic base load. Urine volume increased in response to NaHCO3 infusion. Buffer infusion increased urinary excretion of Na, Mg, and K but decreased Ca excretion for 12 h postfeeding; Cl excretion was not affected. Buffer infusion tended to increase total VFA in ruminal fluid. Our data indicate that homeostatic mechanisms can eliminate exogenous base via the kidneys; hence, acid-base status was not perturbed by infusion of NaHCO3. The increased excretion of Mg and K with buffer infusion indicates that the dietary requirements for these minerals may be increased by NaHCO3. Although loss of Ca through the urine was reduced by buffer infusion, this reduction may indicate reduced availability of Ca to the cow. The diuresis accompanying large doses of NaHCO3 may increase dietary requirements for some minerals.
Eight cases of hepatobiliary invasion of Ascaris lumbricoides into the hepatobiliary tract are presented. In the presence of nonspecific symptoms and biochemical test results, the diagnosis was made in seven patients by sonography. In the remaining patient, in whom the adult roundworm was not visible on sonography owing to the presence of aerobilia, the diagnosis was made at ERCP. Sonography revealed typical tubular, echogenic, filling defects along the long axis of a dilated common bile duct, sometimes exhibiting slow movements and containing a central sonolucent line. Repeated sonographic examinations accurately predicted treatment success.
As part of the search for alternatives to transurethral resection of the prostate (TURP) attention has (re)turned to laser methods. We describe our experience with the currently available endoscopic beam deflection devices, particularly the Prolase II. 25 patients, generally with medical reasons to avoid TURP, and with proven bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPH) underwent prostatic laser coagulation. Average age was 72 years (range 57-84), mean prostatic size by transrectal ultrasound (TRUS) was 48 g (15-100), average pretreatment peak flow rate (FR) was 7.6 ml/s (4.56-12.4). All patients were markedly symptomatic. Patients underwent clinical examination, Prostate specific antigen assay (PSA = 3.75, range 0.1-10.2), and TRUS preoperatively to exclude prostate cancer. After cystoscopic assessment the prostate was lasered according to the device manufacturers recommendations and clinical experience. A suprapubic catheter (SPC) and urethral catheters were inserted, the urethral for 24 hours. If voiding was satisfactory the SPC was removed after 24-48 hrs. Alternatively the patient was discharged and assessed at weekly intervals for SPC removal. Mean duration of SPC drainage was 11 days. Total mean impatient stay was 4.5 days (2-13) during a mean of 2 admissions. Blood loss was minimal and there were no other significant complications. At a minimum follow up of 3 months mean peak FR was 15.3 ml/s (9-31). Symptom scores (IPSS) fell from a mean of 21 to 10 by 3 months after treatment. There was an initial period of irritability for up to 12 weeks but symptomatic improvement was noted in all.
This study endeavours to evaluate the need for sedation in fibreoptic bronchoscopy and response of the patients when sedation is not used. One hundred and five patients divided into three groups of 35 patients each, received buprenorphine (0.3 mg), diazepam (10 mg) and normal saline (0.5 ml) respectively along with atropine (0.6 mg) in each case. The study emphasizes that sympathetic explanation of the details of the procedure to the patients, administration of careful topical anaesthesia and avoidance of sedation makes the procedure acceptable, safe, comfortable with less complications and the need for admitting the patients to the ward is by and large avoided.
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