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Biomedical subjects

V Zaman

Publications and source records attributed to V Zaman.

At least 37 records · Page 2Linked to original sources
PubMed1997

Variation in the cyst morphology of Blastocystis hominis.

Two types of Blastocystis hominis cyst are passed in human feces, one with an outer fibrillar coat and the other without it. The outer fibrillar coat is shed as the cyst matures, but another fibrillar coat forms that is closely attached to the cyst wall and is clearly visible at high magnification in the electron microscope. The internal structure of the two cyst form is similar.

Animals↗
PubMed1997

Observations on the surface coat of Blastocystis hominis.

The surface coat of Blastocystis hominis was studied in the electron microscope. In some cells the surface coat was seen in two layers; the external layer was more electron-dense and fragmented than the internal layer. It appears that the surface coat is being continuously formed by the parasite and shed in the environment. The fibrillar material of the surface coat attaches to the bacteria, in some cases, completely surrounding them, possibly causing cytoplasmic damage to the bacterial cell as indicated by loss of electron density.

Animals↗
PubMed1997

Significantly increased IgG2 subclass antibody levels to Blastocystis hominis in patients with irritable bowel syndrome.

Blastocystis hominis is a common intestinal parasite of humans in the tropics whose pathogenic role is in dispute. Its presence has been reported in a variety of intestinal disorders resembling irritable bowel syndrome (IBS) such as diarrhea, anorexia, and flatulence. We have therefore investigated a possible link between IBS and blastocystosis by determining IgG antibody levels to B. hominis in patients with IBS. Levels of IgG antibodies were significantly elevated in patients with IBS compared with asymptomatic controls (P < 0.0001, by Student's t-test) in both B. hominis stool culture-positive and stool culture-negative IBS patients. When IgG antibodies were divided into their respective subclasses, only IgG2 levels were significantly increased in IBS patients compared with asymptomatic controls, indicating that the predominant response in these patients may be directed to carbohydrate antigens. The diagnostic usefulness of this test in IBS patients remains to be established because these data are only suggestive of a possible link between B. hominis and IBS. However, we hope that this antibody test will help in elucidating the controversy that surrounds the role of B. hominis as a pathogen at present.

Animals↗
PubMed1997

An epidemic of Dengue fever in Karachi--associated clinical manifestations.

Dengue is a mosquito borne disease with worldwide distribution. Depending on virulence factors and host immune status, infection can manifest as a severe but non fatal viral syndrome or a rapidly progressive and a frequently fatal haemorrhagic fever. During the course of an outbreak of viral fever in Karachi, Pakistan from June, 1994 to September, 1995, we studied 145 cases admitted at the Aga Khan University Hospital. 43% of the cases were between the age group of 20-30 years, majority of these being male (75%). Amongst the clinical signs and symptoms, the most frequent findings were fever, vomiting and abdominal pain. Spontaneous hemorrhagic manifestations occurred in 66 patients and of these petechiae and mucosal bleed were the commonest, that is, 42% and 38% respectively. At presentation thrombocytopenia (platelet count < or = 50,000) per cubic millimeter) was present in 78%, leucopenia (white cell count < 4,000 per cubic millimeter) in 34%. Apart from one patient who died from hemorrhagic shock on the 5th day of admission, the remaining patients recovered and their platelet counts normalized on an average in 9 days. This is the first reported epidemic in Karachi of dengue infection.

Adult↗
PubMed1996

The diagnosis of Blastocystis hominis cysts in human faeces.

Blastocystis hominis cysts in faeces can be concentrated on Ficoll column. They are pleomorphic in shape having a mean diameter of 6.65 microns (S.D. = 2.32). They may or may not have a membranous layer surrounding them. The membranous layer tends to come off with pressure or dying of the specimen and corresponds to the fibrillar layer observed under the electron microscope. The Ficoll concentration technique is also useful for concentrating other protozoan cysts.

Animals↗
PubMed1995

Ultrastructure of Blastocystis hominis cysts.

Blastocystis hominis cysts were concentrated from human faeces by repeated washing in distilled water and centrifugation on Ficoll-Paque. This procedure gave a concentrated suspension of cysts without yielding any non-cystic forms. The cysts were examined by both transmission (TEM) and scanning electron microscopy (SEM). Cysts were surrounded by a fibrillar layer that appeared porous in SEM. Many naked cysts without the fibrillar layer were also visible in SEM. They were variable in shape but mostly circular to oval. The diameter of the cyst without the fibrillar layer was 3.5 microns in both TEM and SEM. The nuclear structure was typical of Blastocystis and exhibited multiple mitochondria with poorly developed cristae. Glycogen was present in small to large clumps in the cytoplasm. The cyst wall was 5-100 nm thick and was bounded internally by an electron-dense plasmalemma.

Animals↗
PubMed1995

Bacteria, viruses, yeasts and protozoans associated with diarrheal disease in Singapore.

Labile toxin producing enterotoxic E. coli (ETEC) were the commonest pathogen isolated from diarrheal stools of hospitalized children (21%) and adults (26%) in Singapore. Salmonellas ranked a close second in children (19%). Other bacterial pathogens were isolated from less than 5% of subjects. Blastocystis hominis was detected in 4.3% of diarrheal stools when a simple sedimentation technique was used. Cryptosporidium was not detected at all. An analysis of yeast counts in smears of diarrheal and non-diarrheal stools suggested they were etiologically associated with at least 6% of diarrhea in children and 19% in adults. Testing for rotaviruses by Latex agglutination and for adenovirus by electronmicroscopy showed an association with 6 per cent and 3 per cent diarrhea respectively. The study highlighted a need for: case control studies on ETEC and B. hominis; studies on the epidemiology of diarrhea by yeasts; establishing the true incidence of adenovirus diarrhea; studies on the prevalence and seasonality of rotavirus infection in Singapore.

Adenovirus Infections, Human↗
PubMed1992

A survey of Blastocystis in reptiles.

A total of 28 species of reptiles were investigated for Blastocystis using light microscopy and in vitro culture in biphasic egg slant medium. Blastocystis species were detected in 8 (28.6%) of these 28 species in 3 tortoises (Geochelone elephantopus, G. elegans and G. carbonaria), 3 snakes (Boiga dendrophilla, Python reticulatus and Elaphe radiata), 1 crocodile (Crocodylus porosus) and 1 iguana lizard (Cyclura cornuta). The reptilian Blastocystis appeared to be morphologically similar to B. hominis.

Alligators and Crocodiles↗
PubMed1991

A Blastocystis species from the sea-snake, Lapemis hardwickii (Serpentes: Hydrophiidae).

Observations were made on Blastocystis isolated from the sea-snake, Lapemis hardwickii. Exponential growth of the organism was observed between 2 and 4 days of culture. Vacuolated, amoeboid and granular forms were observed in cultures, similar to B. hominis. The optimal growth temperature for the sea-snake Blastocystis was 24 degrees C compared with 37 degrees C for B. hominis. The karyotypic patterns of B. hominis and the sea-snake Blastocystis were studied in the clamped homogeneous electric field (CHEF) technique and found to be different. Based on the above differences, the sea-snake Blastocystis was designated as Blastocystis lapemi sp. nov.

Animals↗