Search PubMed⌕ Search

Biomedical subjects

M Waseem

Publications and source records attributed to M Waseem.

At least 37 records · Page 2Linked to original sources
PubMed1999

Percutaneous intramedullary elastic wiring of displaced diaphyseal forearm fractures in children. A modified technique.

Under the age of 11 years there are specific anatomic considerations which favour intramedullary wiring of displaced forearm fractures. The isthmus of radius and ulna is narrow (range = 3-6 mm). The medulla is at its widest proximally in the (ulna) and distally in the radius. These are the optimum entry points for intramedullary progression of the wire. At these points there is a low stress raising effect minimising the risk of iatrogenic fracture. A 1.6 mm Kirschner wire is elastic enough to be prebent into a large radius. It is strong enough to resist deformity on entry, though elastic enough to achieve stability by intramedullary three-point contact. The tip of the wire is prebent to 30 degrees aiding closed reduction of displaced fractures. An oblique 4.5 mm drill hole is made through a < 2 cm skin incision avoiding the epiphysis. This allows the wire to be introduced into the intramedullary canal at an optimum angle of 30 degrees. A smaller hole would not allow intramedullary progression e.g.; in a 2.5 mm hole the angle of insertion would be 55 degrees. Wire is now held with a cannulated T-handle, which is tapped with a hammer thus bouncing the wire of the side wall into the medulla. Rotating the handle aids reducing of displaced fractures. There are advantages to this method over other methods of intramedullary fixation e.g.; Steinman pins, Rush pins, or Nancy nails. Also holds advantage over plating. Over the last 12 months 11 cases were treated by the above methods without significant complications.

Bone Wires↗
PubMed1999

Comparative pulmonary toxicity of cadmium and nickel: histopathological and bronchoalveolar lavage analysis.

Pulmonary toxicity of cadmium and nickel was evaluated in rat lungs following intratracheal instillation of their chlorides. Concentration of both the metals varied from 0.2-5 mM. Both the metals increased total number of cells, number of polymorphonuclear neutrophils, total protein, sialic acid and the activity of lactate dehydrogenase and beta-glucuronidase in bronchoalveolar lavage 3 days after exposure. Increase in the levels of the selected parameters was more following Cd exposure than in Ni exposed rats. Histologically there was an inflammatory response and interstitial fibroblastic proliferation in the lungs of Cd exposed animals. These changes were mild in Ni-exposed animals and higher concentrations of Ni were needed to produce changes similar to those produced by smaller concentrations of Cd.

Animals↗
PubMed1996

Pulmonary clearance of Candida albicans: effect of exposure to native and metal-coated fly ash.

The viability of Candida albicans was tested at various intervals in the lungs of rats following single intratracheal inoculation of the yeast cells. Most of the inoculated cells were cleared from lungs within 48 hr after exposure. Clearance was enhanced in lungs exposed to metal-coated fly ash than in those exposed to native fly ash. The validity of these studies was verified in vitro using peritoneal macrophages of mice exposed in vivo to native and metal-coated fly ash. An increase in phagocytic and intracellular killing of macrophages harvested from animals exposed to native or metal-coated fly ash was observed.

Animals↗
PubMed1996

A comparative study of unpassaged and animal passaged cultures of Listeria monocytogenes in rabbits.

Variants of a parent culture of Listeria monocytogenes were prepared by passaging it several times through rabbits. The resulting isolates (V1 to V6) were investigated and compared with the parent culture with particular emphasis on their phenotypic characters and their pathogenicity for rabbits. The variants maintained the morphological, cultural, biochemical and serological features of the parent strain. Although no significant decrease was noted in the total extracellular protein produced, 10 mg/ml of a 6-day culture broth grown at 34 degrees C for V6 as compared to 12.3 mg/ml for the parent culture, the phosphocholine-specific phospholipase C (PC-PLC) activity diminished with passaging. Pathogenicity for rabbits, as determined by viable count of the organism per gram of the infected organ, increased at each passage. Animals infected with V6 revealed a mean of 2.2 x 10(9) CFU/g of spleen as compared to the parent culture which had a count of 5.0 x 10(6) CFU/g. These observations indicate a lack of direct correlation between in vitro production of PC-PLC and virulence of L. monocytogenes for rabbits.

Animals↗
PubMed1995

Correlation between production of listeriolysin O by variants of Listeria monocytogenes and their virulence for rabbits.

L. monocytogenes serovar 1/2a NCTC 7973 was passaged through rabbits and the severity of infection at each passage was determined by counting viable bacteria from infested organs and recording the time of death. A comparative evaluation of the levels of hemolysin produced in vitro by the original and six variant cultures (V1-V6) was done by determination of hemolytic units (CHU). While virulence of the cultures enhanced at each passage (2.2 x 10(9) CFU/g of the spleen for V6 as compared to 5.0 x 10(6) CFU/g spleen for the parent culture), the CHU decreased considerably, 3 CHU for the V6 as compared to 40 CHU for the parent strain. The results suggest that the level of in vitro production of listeriolysin may not parallel the pathogenicity of L. monocytogenes for rabbits.

Animals↗
PubMed1994

Pulmonary response to cadmium and nickel coated fly ash.

Pulmonary reaction to fly ash coated with cadmium (Cd) or nickel (Ni) and to native fly ash was studied in rats after intratracheal inoculation of dust suspensions. The histopathological alterations and changes in biochemical and cellular constituents of the bronchoalveolar lavage were correlated with the metal content in lungs and kidneys. More Ni was adsorbed than Cd on fly ash particulates. Metal-coated fly ash was more toxic than uncoated fly ash. Cd-coated fly ash produced significantly more histopathological and biochemical changes than Ni-coated fly ash. A high concentration of Cd was detected in the kidneys of rats exposed to Cd-coated fly ash.

Adsorption↗
PubMed1992

Ranking toxicity of industrial dusts by bronchoalveolar lavage fluid analysis.

Female wistar rats were inoculated intratracheally with 10 mg/ml suspensions of various dusts, viz: quartz, fly ash, mica and corundum in physiological saline. Biochemical markers of bronchoalveolar lavage fluid (BALF) were analysed 8 days after the instillation of the dusts. Elevated levels of proteins, sialic acid and phospholipid contents and the activity of lactate dehydrogenase correlated well with the degree of the known fibrogenic potential of different dusts in the lungs in the following order, quartz greater than fly ash greater than mica greater than corundum. beta-glucuronidase activity, was however, only elevated in the quartz inoculated group of rats. It is suggested that biochemical constituents of BALF analysed shortly after the exposure to different dusts can be useful to mirror alterations in the tissue response to mineral dusts.

Aluminum Oxide↗
PubMed1990

Modification of pulmonary silicotic reaction in rats exposed to coal fly ash.

Quartz exposure resulted in an increase in the wet weight, dry weight and collagen contents of lungs. Animals inoculated comparable amounts of fly ash revealed a statistically insignificant increase in these parameters. In silicotic rats exposed to fly ash the increase in the wet weight, dry weight and collagen contents of lungs was reduced in comparison to silicotic animals unexposed to coal fly ash. Histological examination of lungs revealed the development of silicotic granulomata with reticulin and collagen fibre formation. The difference in the development of these lesions was less pronounced when a blindfold comparison was made between the silicotic animals, exposed or unexposed to coal fly ash. The increased activity of LDH in the bronchoalveolar lavage (BAL) of rats exposed to quartz alone was mitigated significantly in silicotic animals subsequently exposed to coal fly ash. The protein content of the BAL increased significantly more in quartz-fly ash exposed animals than in rats exposed to either dust alone. The total cellular elements of the BAL were increased in rats exposed to quartz alone (p less than 0.005). The results demonstrate that fly ash exposure can significantly modify the development of a silicotic pulmonary reaction.

Animals↗
PubMed1990

Alterations in in vitro functional activities of alveolar macrophages exposed in vivo to mineral dusts.

To determine whether macrophages exposed to mineral dusts are altered, rats were exposed intratracheally to one of several mineral dusts, held 8 days, their lungs washed and the cellular composition of the fluid characterized morphologically and functionally. The number of cells recovered from lung washings of exposed rats increased 2 to 5 times relative to control rats; however, the percentage of such cells that were macrophages, or were capable of phagocytosis, adherence to glass or metabolism of carbohydrates via the hexose monophosphate shunt as indicated by reduction of nitroblue tetrazolium, were reduced. Silica dust produced the greatest effect, corresponding qualitatively to earlier in vivo studies.

Aluminum Oxide↗
PubMed1988

Reaction of macrophages activated by agents in vivo to quartz dust in vitro.

A comparative study was made of the cytotoxic action of quartz dust in vitro on macrophages activated in vivo by intraperitoneal inoculation of physiological saline, thioglycolate and starch. The liberation of lactate dehydrogenase (LDH) into the supernatant culture medium, adherence to a plastic surface, extent of acid dye exclusion and ultrastructural alteration in the surface morphology of macrophages were taken as parameters of the cytotoxic action of the dusts. Thioglycolate and starch stimulated cells when exposed in vitro to quartz dust released more LDH into the supernatant culture medium and resulted in a greater decrease in macrophage adherence than similarly exposed cells derived from saline stimulated animals. No difference was observed between cells obtained from differently stimulated animals in increased acid dye uptake, loss of surface filopodia and rounding of cells which phagocytosed quartz particles. The results show that quartz is cytotoxic for macrophages, irrespective of their degree of activation and the extent of damage induced is related to the chemical agent used for activation of macrophages in vivo.

Animals↗
PubMed1985

Pulmonary response to agate dust in vivo and cytotoxic and haemolytic effects in vitro.

The pulmonary response to agate dust in vivo was investigated and also its cytotoxic action on peritoneal macrophages and sheep erythrocytes in vitro. The results were compared with quartz dust as the known fibrogenic dust and emery dust (Corundum) was used as a control dust. Agate increased the wet and dry weight of lungs and induced increased collagen formation and a non-reversible fibrotic reaction in the lungs. The tissue response and lung changes were of milder intensity than seen in rats exposed to quartz. In vitro, the extent of dye-uptake and haemolysis yielded results similar to those of the in vivo studies. Release of lactic dehydrogenase into the culture medium was similar in both the agate and emery exposed cells but significantly less when compared with quartz treated cells.

Animals↗
PubMedDate not supplied

Toxicity of trichloroethylene following inhalation and drinking contaminated water.

The neurobehavioural effects of trichloroethylene (TCE) were studied in rats following administration of the solvent orally (350, 700 and 1400 ppm in drinking water for 90 days) and through inhalation (376 ppm for 4 h a day, 5 days per week for 180 days). Various aspects of spontaneous locomotor activity were assessed at different periods after exposure through either of the routes. Oral exposure to TCE had no significant effect on spontaneous locomotor activity or cognitive ability, whereas inhalation to the solvent resulted in an increase in the distance travelled and horizontal activity counts at day 30 but a decrease at day 60 of exposure. The time spent in ambulatory and stereotypic movements as well as the number of stereotypic movements were enhanced significantly only at day 30. The resting time was decreased at day 30 but enhanced at day 60 of exposure. The learning ability was not affected significantly up to day 180. The results highlight the neurotoxic potential of inhalation exposure to TCE.

Administration, Oral↗