Biomedical subjects
K Osman
Publications and source records attributed to K Osman.
The tropism of organ involvement in primary systemic amyloidosis: contributions of Ig V(L) germ line gene use and clonal plasma cell burden.
Primary systemic amyloidosis (AL) is a protein conformation disorder in which monoclonal immunoglobulin light chains produced by clonal plasma cells are deposited as amyloid in the kidneys, heart, liver, or other organs. Why patients with AL present with amyloid disease that displays such organ tropism is unknown. This study tested the hypothesis that both the light-chain variable region (Ig V(L)) germ line genes used by AL clones and the plasma cell burden influenced AL organ tropism. To assess the renal tropism of some light chains, an in vitro renal mesangial cell model of amyloid formation was used. With reverse transcription-polymerase chain reaction, Ig V(L) genes were sequenced from 60 AL patients whose dominant involved organs were renal (52%), cardiac (25%), hepatic (8%), peripheral nervous system (8%), and soft tissue and other (7%). Patients with clones derived from the 6a V(lambdaVI) germ line gene were more likely to present with dominant renal involvement, whereas those with clones derived from the 1c, 2a2, and 3r V(lambda) genes were more likely to present with dominant cardiac and multisystem disease. Patients with V(kappa) clones were more likely to have dominant hepatic involvement and patients who met the Durie criteria for myeloma (38%, 23 of 60) were more likely to present with dominant cardiac involvement independent of germ line gene use. In the in vitro model, unlike all other AL light chains tested, lambdaVI light chains formed amyloid rapidly both with and without amyloid-enhancing factor. These data support the hypothesis that germ line gene use and plasma cell burden influence the organ tropism of AL. (Blood. 2001;98:714-720)
Deep venous thrombosis and thalidomide therapy for multiple myeloma.
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Toxic and essential elements in placentas of Swedish women.
OBJECTIVES: To evaluate interactions between toxic and essential elements in the mother-fetus relationship and possible predictors of trace element concentrations in placenta and cord blood. DESIGN AND METHODS: A group of 106 Swedish women was investigated for concentrations of cadmium, lead, and several essential elements in placenta as well as cadmium, lead, zinc, and selenium in venous blood collected at gestational week (gw) 36 and umbilical cord blood. Relations between these elements and maternal and child's characteristics were examined. RESULTS: The concentrations of cadmium in placenta ranged from 10 to 170 nmol/kg, with the median value (Md) being 46 nmol/kg. Cord blood cadmium (Md of 0.19 nmol/L) was only about 10% of that in maternal blood. Smokers had significantly higher cadmium concentrations in blood (p < 0.001) and placenta (p = 0.001) than non-smokers. The median placental concentration of lead was 26 nmol/kg (range 0-630 nmol/kg). The lead levels in cord blood (Md of 54 nmol/L) were almost the same as in maternal blood. Statistically significant negative associations were found between cord blood lead, on one hand, and child's weight, length, and head circumference, on the other. The placental levels (medians and ranges) of the essential elements (micromol/kg) were 160 (120-280) for zinc, 2.4 (2.0-3.3) for selenium, 15 (10-20) for copper, 0.084 (0.02-0.32) for cobalt, 0.055 (0.03-0.12) for molybdenum, and 1.2 (0. 65-5.1) for manganese, respectively. Several of the essential elements in placenta correlated significantly with each other. Multiparous mothers had significantly lower concentrations of zinc (p = 0.002) and selenium (p = 0.049) in serum as well as zinc (p = 0. 001) and calcium (p = 0.004) in placenta than nulliparous ones. Also, cord blood zinc decreased with parity. CONCLUSIONS: The results showed that lead, but not cadmium crossed easily the placental barrier. There were no negative effects of cadmium on the zinc status. Cord blood lead, on the other hand, was a negative predictor of child's birth weight, length and head circumference, indicating that lead might have negative influence on growth in children even at very low exposure levels. There was a depletion of maternal stores of essential elements with increasing parity.
Lead exposure and hearing effects in children in Katowice, Poland.
The objective of the study was to investigate the relationship between lead exposure and hearing in children in the Katowice region, an industrial area in Poland. Blood lead was determined using inductively coupled plasma mass spectrometry, with appropriate quality control. The concentrations of lead in blood (B-Pb) in 155 children, aged 4-14, ranged from 19 to 281 microg/L (0.09 to 1.4 micromol/L), with a median of 72 microg/L (0.34 micromol/L). The hearing thresholds increased significantly with increasing blood lead levels at all investigated frequencies (0.5, 1, 2, 4, 6, and 8 kHz). The relationship also remained significant for B-Pb below 100 microg/L (0.48 micomol/L; n=107). The brainstem auditory evoked potential latency of wave I was significantly increased (also after adjustment for age) in the group of children with the highest blood lead levels (B-Pb above 100 microg/L, 0.48 micromol/L; n=51), compared to the group with the lowest ones (B-Pb below 46 microg/L, 0.22 micromol/L; n=51). The audiometric results clearly indicate that auditory function in children is impaired at a blood lead concentration even below 100 microg/L (0.5 micromol/L).
Exposure to lead and other metals in children from Katowice district, Poland.
OBJECTIVES: To assess the exposure to toxic metals and to evaluate its possible association with essential elements and socioeconomic status in children from the town of Bytom in the Katowice area; this area is one of the most polluted industrialized regions in Poland. METHODS: Concentrations of lead, cadmium, mercury, selenium, magnesium, copper, and zinc were determined in whole blood of 211 children aged 9 years. The samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Information on socioeconomic factors was collected using questionnaires. Concentrations of trace elements in the blood of 24 Swedish children aged 9-10 years were used for comparisons. RESULTS: The concentrations of lead detected in the blood of the Polish children ranged from 0.09 to 1.9 mumol/l, with the median value being 0.27 mumol/l. Statistically significant associations were found between lead and such socioeconomic factors as the number of siblings, trips outside the region, maternal smoking, playing outdoors, and apartment standard. The average blood lead level was about 3 times higher in the Polish children than in the Swedish group. The median blood concentration of cadmium found in the Polish children was 3.4 nmol/l (range 1.1-41 nmol/l; almost 3 times higher than that detected in the Swedish children), and that of mercury was 3 nmol/l (range 0.5-11 nmol/l). The median blood levels and ranges of the essential elements were 1.1 (0.7-2.0) mumol/l for selenium, 1.5 (1.2-1.9) mmol/l for magnesium, 17 (13-22) mumol/l for copper, and 78 (54-104) mumol/l for zinc, respectively. The concentrations of selenium and magnesium were significantly lower in the Polish group as compared with the Swedish children. CONCLUSIONS: In all, 7% of the Polish children had blood lead levels exceeding 0.5 mumol/l, the concentration above which negative effects on mental development have been reported. However, the findings indicate a decrease in lead exposure during recent years among the Bytom children.
Interactions between essential and toxic elements in lead exposed children in Katowice, Poland.
OBJECTIVES: To determine the influence of the essential element status on blood concentrations of lead and other toxic metals. DESIGN AND METHODS: A group of 157 children from Katowice, an industrial area in Poland, was investigated for concentrations of lead and cadmium in whole blood, and mercury, selenium, zinc, copper, and magnesium in whole blood and serum. Relations between these elements, serum ferritin, hematological parameters, as well as serum selenoprotein P and glutathione peroxidase (GSH-px) were examined. Conversion factors for element concentrations (mumol to microgram): lead 207.19, cadmium 112.41, mercury 200.59, selenium 78.96, magnesium 24.31, copper 63.55, and zinc 65. RESULTS: Blood lead was negatively associated with concentrations of selenium in whole blood and serum as well as selenoprotein P and glutathione peroxidase in serum. The association was mainly apparent at low blood lead concentrations, which may indicate an influence of selenium on the kinetics of lead, rather than an effect of lead on the selenium status. Children with low serum ferritin levels had statistically higher blood cadmium levels and a tendency for higher blood lead levels, indicating increased gastrointestinal absorption of these metals at reduced iron stores. Blood lead was negatively correlated with mean corpuscular hemoglobin concentration, which may reflect the effect of lead on hemoglobin synthesis. There was an association between blood mercury and selenium, indicating a common source of intake through fish consumption. CONCLUSIONS: The results indicate that selenium and iron status may influence the kinetics of lead.
Percutaneous balloon dilatation of aortic coarctation in adults.
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Transthoracic and transesophageal echocardiographic diagnosis of severe subaortic obstruction produced by an abscess cavity.
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Plasma oxidase assay for screening of myocardial infarction.
The availability of techniques such as surgical reperfusion, angioplasty, and thrombolysis for the treatment of acute myocardial infarction (AMI) has revived interest in seeking an early detectable biochemical marker diagnostic for AMI. Therefore, we investigated whether an unidentified oxidase that is released by activated neutrophils at the onset of AMI could be used as an early diagnostic assay. The conversion by plasma oxidase of 1 microM of adrenaline to 1 microM of adrenochrome represents the plasma oxidase activity (POA) of 1 U/L. Fifty patients suspected of having AMI, 40% of whose electrocardiograms were nondiagnostic for AMI, were admitted to the coronary care unit, and venous blood samples were obtained for determination of the POA and creatine phosphokinase-MB levels. Healthy volunteers (n = 12) served as control subjects, and 8 patients with pneumonia whose leukocyte counts were greater than 15,000 microL were included in the study. In those with AMI (n = 22), as determined by serial creatine phosphokinase-MB, the mean POA (+/- standard error of the mean) was 233 +/- 13 U/L, and in those with angina and no AMI (n = 28) was 127 +/- 5 U/L (P < 0.0001). In the control group, mean POA (+/- standard error of the mean) was 84 +/- 5 U/L (control versus angina; P < 0.01) and for those with infection was 214 +/- 10 U/L. At admission, the creatine phosphokinase-MB was diagnostic for only 12 of the 22 patients with AMI (sensitivity rate of 54%), whereas in 21 of those patients, the POA values were diagnostic for AMI (sensitivity rate of 95%).(ABSTRACT TRUNCATED AT 250 WORDS)
Percutaneous balloon angioplasty for the coarctation of the aorta in neonates and children.
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Cytochemical identification of cholinergic amacrine cells in cat retina.
Golgi studies of cat retina have revealed the presence of matching subpopulations of starburst-like amacrine and displaced amacrine cells that are morphologically similar to the cholinergic cells of rabbit retina. The displaced amacrines appear identical with the A14 cells described by Kolb et al. (Kolb, Nelson, and Mariani: Vision Res. 21:1081-1114, 1981). In order to determine whether these cells may be cholinergic, we carried out autoradiography to localize newly synthesized (3H)acetylcholine and immunocytochemistry to demonstrate the distribution of choline acetyltransferase. Autoradiographs showed labeling in somas of both amacrine and displaced amacrine cells. Choline acetyltransferase was found in amacrine cells that ramify in sublamina a of the inner plexiform layer and in displaced amacrine cells ramifying in sublamina b. The pattern of cholinergic neurons in the cat is similar to that in other vertebrates and suggests that acetylcholine may play an important and consistent role in retinal function.
Acetylcholinesterase localization in cat retina: a comparison with choline acetyltransferase.
Cytochemical localization of acetylcholinesterase (AChE) in cat retina showed reactivity in at least two types of amacrine cell and in essentially all of the cells in the ganglion-cell layer. Reaction product was present throughout the inner plexiform layer (IPL) with heavier accumulations forming bands at 0-6% and 64-78% depth levels. All of the reactivity was abolished by incubation with BW 284c51, a specific inhibitor of AChE. After pretreatment of animals with diisopropylfluorophosphate, new enzyme was synthesized by both amacrine and ganglion cells. In contrast, choline acetyltransferase immunoreactivity was limited to matching subpopulations of amacrine (A14) and displaced amacrine (dA14) cells, ramifying narrowly at 20% and 49% depth levels within the IPL. Combined localization of both enzymes in the same tissue confirmed the presence of AChE in cholinergic cells. However, the greatest concentration of AChE in the IPL was in strata not receiving direct cholinergic input. These findings affirm that AChE is not a reliable marker for either cholinergic or cholinoceptive neurons. The distribution of AChE in the cat retina suggests that this enzyme may participate in functions not directly related to cholinergic neurotransmission.
Studies on histoplasmosis farciminosi (epizootic lymphangitis) in Egypt. Isolation of Histoplasma farciminosum from cases of histoplasmosis farciminosi in horses and its morphological characteristics.
Isolation of Histoplasma farciminosum from five horses, showing typical signs of histoplasmosis farciminosi (epizootic lymphangitis) was successfully attempted. The mycelial form of H. farciminosum was isolated on Sabouraud dextrose agar enriched with 2.5% glycerol, brain heart infusion (BHI) agar enriched with 10% horse blood and PPLO dextrose glycerol agar. The last medium proved to be the most effective, both for primary isolation and subculturing of the fungus. It was found that on primary isolation, the lag phase of the mycelial form of the fungus was relatively long, involving 4-8 weeks at 25 degrees C. Colonies of the mycelial form of H. farciminosum appeared on subculture as a yellowish, light brown to deep brown, convoluted, waxy, cauliflower-like growth tending to form scant aerial growth. Conversion of the mycelial form to the yeast form of H. farciminosum was successful by subculturing either on BHI agar with 5% blood or on Pine's medium and incubating at 35-37 degrees C. Complete conversion to the yeast form was achieved only after 4-5 repeated serial transfers onto fresh media every 8 days. The yeast colonies were flat, raised, slightly or deeply wrinkled, white to light gray to grayish brown, and were pasty in consistency.
Identification of species and biotypes of the brucella genus in apparently healthy and aborted ewes and goats in Egypt.
Brucella micro-organisms was absent in the vaginal swabs collected from apparently healthy ewes. Such incidence among the genital tract of aborted ewes was 4.84%. Among goats, brucella species represented 7.04% in aborted goats, while it was recovered in lower percentage (0.92%) from the vaginal swabs of apparently healthy goats. Br. melitensis biotype "3" was the sole species recovered from aborted ewes, while biotypes "3" and "2" could be obtained from clinically healthy and aborted foeti of goats. The predilection seats of brucella in the genital tracts of aborted animals and their foeti were discussed in details.
Evaluation of serodiagnostic methods for brucellosis among sheep and goats in Egypt.
A total of 1246 animals (778 sheep and 468 goats) were examined for detection of brucellosis using serum tube agglutination test (SAT), complement fixation test (CFT) as well as Abortus Bang Ring test (ABR-test) have been conducted on both dairy ewes and goats. Eighteen ovine sera played positive serum agglutination reactions (2.31%). Out of the total 468 goat's serum samples examined, 22 (4.70%) gave a positive titers and 2 (0.43%) gave doubtful reactions. The reactors of sheep to the CFT was 2.44% and the incidence was lower in rams (1.63%) than among ewes (2.97%). Seven out of the 339 ewe's milk samples were positive to ABR-test (2.06%), 7 were doubtful (2.06%). Out of 354 goat's milk samples examined, 14 were positive to ABR-test (3.96%). CFT was considered to be a reliable procedure for detecting brucella infected animals particularly in male more than the SAT. Among dairy ewes, both tests were identical in their results.
[Antibiotic sensitivity of various atypical mycobacteria in vitro].
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Team efficiencies on a paced visual inspection task.
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