Biomedical subjects
Publications and source records attributed to A Mohammed.
We report the case of a 72-year-old gentleman with mesenteric angina who was successfully treated with stenting of a coeliac artery stenosis using a Palmaz stent, and review the therapeutic options in the management of mesenteric angina.
Antibodies that bind phospholipid (anti-phospholipid antibodies [APA]) are a focus of major interest to both clinical and laboratory personnel across a variety of disciplines because of the assortment of disorders with which they are reportedly associated. A solid phase assay using cardiolipin as the test phospholipid (anti-cardiolipin antibody assay [ACA]) has now become a laboratory standard for the detection of APA. In the current report, data from two separate external quality assurance programs (QAP) and collected over the past four years, have been evaluated to assess the utility of the ACA. Despite attempted standardizations, exceedingly high inter-laboratory variation and a general lack of test result consensus would signal the adoption of a cautious clinical approach towards laboratory findings. For example, for a total of 21 cross-laboratory tested serum samples (tested for both IgG and IgM for 41 quantitative estimations), inter-laboratory variation for both ACA-IgG and ACA-IgM was higher than 50% in 20 of 41 testing cases (48.8%). The situation with regard to testing consensus was equally concerning. Total consensus (i.e., 100% of participating laboratories agreed that a given serum sample gave an ACA result of either negative or positive) occurred in less than 20% of cases for ACA-IgG. More importantly, in about 50% of serum testing occasions there was no general consensus in returned laboratory data (i.e., more than 80% of labs could not agree on whether a serum sample tested was either ACA-positive or ACA-negative). Thus, despite attempted international standardizations, exceedingly high inter-laboratory variation and a general lack of test result consensus would argue that the assay has limited utility. We conclude that single point laboratory results must be used with considerable caution before accepting that ACA activity is present in patient serum or not. We agree with recommendations indicating that laboratory tests should be repeated at least once prior to making a clinical diagnosis of any APS-like disorder.
Explore the source record for details and available documents.
In this article the regional dose equivalent for exposure to 1 working level month (WLM), the annual effective dose equivalent and the dose equivalent conversion factor due to the inhalation of short-lived radon progeny (218Po, 214Pb and 214Bi/214Po) are calculated with a dosimetric model. Experimental results of aerosol size characteristics, unattached activity fractions, equilibrium factors, and activity size distributions of the short-lived radon progeny in indoor and outdoor atmosphere are summarized. Dose calculations based on these results show that the changes in dose rate values are influenced by the different model assumptions concerning deposition probabilities of aerosol particles in the respiratory system during inhalation, the sensitivity of different cells (epithelial, basal) to radiation and assuming nose or mouth breathing. The inverse relationship between the unattached fraction of potential alpha-particle energy in room air and the radioactive equilibrium between radon gas and its progeny indicates that dose equivalent is closely related to the concentration of radon gas averaged over a period of exposure.
The syntheses and radiolabelling of 27 new N-(alkylaminoalkyl)-4-methoxy-, -4-hydroxy-, and -4-aminobenzamides are described and evaluated in C57B1/6 mice with subcutaneously transplanted B16 melanoma in order to screen the optimal chemical structure for melanoma scintigraphy. Using T1(TFA)3 for 131I- labelling, a series of radioiodinated 4-methoxy benzamide derivatives proved to exhibit superior melanoma uptake with outstanding melanoma/non-target-tissue ratios. From the benzamide derivatives tested, N-(2-(1'-piperidinyl)ethyl-3-[131I]iodo-4-methoxybenzamide and N-(2-diethylaminoethyl)-3-[131I]iodo-4-methoxybenzamide demonstrated best results. The introduction of 4-hydroxy and 4-amino groups led to less favourable benzamides. While the former compounds showed little melanoma uptake, the latter revealed unfavourable melanoma/non-target-tissue ratios. Additionally, it could be shown that an amino group was inevitably necessary for melanoma uptake, and that dialkylation of the amide nitrogen and replacing CONH by CH2NH revealed less advantageous results.
In an attempt to predict the trends which might occur in the changing patterns of corneal surgery in the next decade and hence the financial implications, a retrospective study of the treatment of corneal disease was carried out using the pathological reports issued during the last 25 years in the West of Scotland Ophthalmic Pathology Service. This is a supra-regional specialist service which covers the major population areas in Scotland, although most of the specimens were submitted by consultants in the teaching hospitals in Glasgow. The major indications for surgery in the 1486 specimens received were post-inflammatory scarring (387 cases), repeat penetrating keratoplasty (309), keratoconus (257), Fuchs' dystrophy (120) and secondary endothelial failure after cataract surgery (158). In the past 6 years the indications changed and the commonest indications were secondary endothelial failure and post-inflammatory scarring. The study demonstrates a regional difference when compared with other reports and highlights the increasing demand for penetrating keratoplasty and the consequent resource implications.
We have evaluated the technical performance of the MDA-180 automated coagulation analyser in a working diagnostic hemostasis laboratory environment. The analyser has been on site now for over 18 months, and has undergone considerable testing. More than 22,000 samples have been processed, with over 90% of these via the MDA-180's cap-piercing facility. The instrument has been primarily assessed for its technical ease of use and continued reliability, as well as its analytical performance. The instrument has also been successfully interfaced to, and used with, our Laboratory information (CERNER PATHNET) system. A major feature of our evaluation has been an assessment of the MDA-180's ability to perform assays currently performed using alternative methodology or instrumentation (eg; ELISA methodology or the Coagamate-X2 and ACL-300R instruments), as well as its potential to streamline the technical performance of some of these assays. We have co-evaluated the following assays: PT/INR, APTT, TT, Fibrinogen, Protein C, ATIII, Factors II, V, VII, VIII, IX, X, XI, and XII, Lupus anticoagulant (dRVVT), and heparin (alpha Xa). In addition, a number of different reagents (particularly for PT and APTT assays) have been tested on the instrument. Intra-assay and inter-assay variation appears to be remarkably low (five different plasmas tested: PT: 0.6 to 1.3% and 0.5 to 1.3% respectively; APTT: 0.7 to 3.2% and 0.6 to 3.6% respectively; single day analysis). Other comparative assessment data typically showed good correlation to existing test assay systems. A review of other features which may enhance or detract from the instrument's worth in a given hemostasis laboratory is also presented. In summary however, we conclude that the instrument is reliable, easy to use and capable of fast sample through-put.
UNLABELLED: The development of an effective radiopharmaceutical with affinity for malignant melanoma has been a research goal for some time. The early detection of melanoma metastases would greatly improve the therapy outcome for this disease. This article describes the synthesis of radioiodinated IMBA, N-(2-diethylaminoethyl)-3-[123I/131I]iodo-4-methoxybenzamide 8, its organ distribution, its comparison with BZA and other benzamides, and demonstrates the scintigraphic efficacy of the title compound with three melanoma patients. METHODS: The syntheses and radioiodination of eight benzamide derivatives are described. After intravenous injection into C57B16-mice subcutaneously transplanted with B16 melanoma, the organ distribution of the respective benzamides were investigated at 1 and 6 hr. n-octanol/phosphate buffer partition coefficients. The wholebody retention, erythrocyte and serum protein bound fractions of radioiodinated benzamides were measured. RESULTS: While structural changes in the amide substituents of N-(2-dialkylaminoalkyl)-4-iodobenzamides 2-7 resulted in no improvement in organ distribution compared with BZA, the 3-iodo-4-methoxyphenyl form of IMBA showed high melanoma uptake with significantly higher melanoma/nontarget tissue ratios. Compared with BZA the average ratio improved after 1 hr by a factor of eight and was still four times better after 6 hr. BZA and IMBA exhibit almost identical n-octanol/ phosphate buffer partition coefficients, however, IMBA has a faster urinary excretion facilitated by a lower affinity to erythrocytes and serum proteins; this could explain the improved tissue partinioning observed. Scintigraphy of patients with melanoma metastases confirmed the promising characteristics derived from the animal studies. CONCLUSION: Due to rapid background clearance and high melanoma affinity, IMBA showed high tumor contrast already at 4 hr after injection which makes it a promising new radiopharmaceutical for the scintigraphic detection of melanoma metastases.
SETTING: A voluntary health worker project (Operation Elsies River) was started in a high incidence tuberculosis (TB) area in the Western Cape of South Africa, in order to assist the local TB Control programme with case-holding. OBJECTIVE: To evaluate the effectiveness of this group of volunteers in enhancing adherence of notified TB patients to tuberculosis treatment. DESIGN: A cohort study was conducted with 351 TB patients (203 children and 148 adults). RESULTS: The data from the child and the adult groups were analysed separately. The child group was more adherent to TB treatment than adults. The supervision option with staff dedicated to the treatment of TB, such as the clinic and the SANTA crèche, achieved better adherence results for pre-school children. The supervision modalities for adults did not differ in their adherence performance even following adjustment for confounders. CONCLUSION: The supervision option provided by the volunteers did not significantly improve the adherence of adult patients to antituberculosis treatment.
Long-term adrenalectomy results in loss of neurones in the hippocampal formation of the adult rat. The effects of long-term adrenalectomy on spatial learning and exploratory behaviour in adrenalectomized (ADX), adrenalectomized normal weight gain (ADXNW), sham operated and naive control male Sprague-Dawley rats were investigated in this study. The ADX rats had significantly longer latencies in the Morris maze task compared to the other groups. In the open-field situation, as a novel finding, the ADX rats showed significantly lower rearing scores compared to other groups. These data indicate that long-term adrenalectomy causes impairment in spatial learning and explorative behaviour in the rat.
Explore the source record for details and available documents.
We have identified situations in which filtered plasma is provided to the laboratory for combined assessment of lupus anticoagulant, as well as other diagnostic haemostasis laboratory procedures. On the basis of laboratory investigation, however, we report that significant errors in test result interpretation can arise should this occur and depending on the specimen processing procedure, and whether filtered plasma is used for multiple assays. Citrated plasma samples were obtained from 12 normal individuals and a portion of each sample filtered using a standard 0.22 micron filter. Small volumes were frozen for later analysis. We could detect a statistically significant difference (P < 0.01) between filtered plasma and non-filtered plasma in most test results. Most notable were changes in the APTT, fibrinogen, FVIII and vWF, where results often fell outside the normal reference range of the assay. Such assay results closely mimic those obtained with type 2 von Willebrand's disease (vWD) patients, thus should filtered plasma unknowingly be tested for vWF, a wrong conclusion of type 2 vWD could easily arise. Assay results for other parameters may similarly draw incorrect conclusions, such as mild haemophilia A and dysfibrinogenaemia. In summary, we report that following filtration not only are a variety of coagulation test results altered, but reduced plasma levels of some coagulation factors could potentially lead clinicians incorrectly to diagnose congenital or acquired deficiencies or defects. We recommend that laboratories note that (other than for lupus anticoagulant) filtered plasma is not appropriate for the coagulation laboratory, and that any abnormal haemostasis test result following such combined testing be considered a potential artifact and independently repeated to confirm any putative abnormality prior to drawing any clinical conclusions.
Explore the source record for details and available documents.
One hundred and three patients with eclampsia were managed during a period of eleven years. The perinatal mortality rate was 136 per 1000 total births and there were six maternal deaths. The maternal mortality rate was less among eclamptics delivered by Caesarean Section. Liberal use of diazepam and/or magnesium sulphate and early recourse to Caesarean Section were integral in the care of these women.
Plasma biochemical changes were studied for 8 consecutive weeks in Sokoto Red goats experimentally infected by intravenous route injection of 1.6 x 10(7) Trypanosoma brucei. The strain 8/18 was highly infective. The mean packed cell volume significantly decreased from 1 to 8 weeks post-infection (PI) at P < 0.05. During this period, the mean plasma total bilirubin concentrations significantly increased (P < 0.05). The mean plasma direct and indirect bilirubin concentrations significantly increased from 2 to 8 weeks PI (P < 0.05). The mean plasma albumin concentrations did not vary significantly (P > 0.05), but the mean total plasma proteins and mean plasma globulin concentrations significantly increased between 5 and 8 weeks post infection (P < 0.05). There were no significant changes in the mean plasma bicarbonate, creatinine and cholesterol concentration (P > 0.05).
An attempt at correlating atmospheric temperature, humidity and histologically diagnosed anovulatory endometrium has been made. A total of 140 women who had anovulatory endometrium among 1036 patients who had a clinical diagnosis of primary infertility, over a 5 yr period were studied. The principle of Edwards' test was used to analyse the seasonal trends and the seasonal index for the occurrence of anovulatory endometrium, atmospheric temperature and humidity was calculated using the average percentage method. The results suggest that anovulatory cycles in women with infertility tended to occur more during those months in the year when temperature increased (r = 0.63). However, humidity was not related to anovulation.
Explore the source record for details and available documents.
Explore the source record for details and available documents.