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Biomedical subjects

K Suresh

Publications and source records attributed to K Suresh.

At least 55 records · Page 3Linked to original sources
PubMed1995

Elucidation of the life cycle of the intestinal protozoan Blastocystis hominis.

This paper elucidates the status of the different morphological forms of Blastocystis and reports the existence of thin- and thick-walled cysts in B. hominis on the basis of current experimental evidence. It is suggested that the thin-walled cysts are autoinfectious, leading to multiplication of the organism in the intestinal tract. The thick-walled cysts are responsible for external transmission via the faecal-oral route. A life cycle for B. hominis is postulated on the basis of these findings.

Acridine Orange↗
PubMed1995

Tubulovesicular elements in Blastocystis hominis from the caecum of experimentally-infected rats.

By transmission electron microscopy (TEM), tubulovesicular elements were seen in Blastocystis hominis obtained from the caecum of experimentally-infected rats. These appeared to arise from the peripheral cytoplasm and were rounded, oval or elongate in sections. It is suggested that these elements form a network for transfer of nutrients to the periphery during the process of encystation.

Animals↗
PubMed1995

Environmental physiology of the mole crab Emerita asiatica, at a power plant discharge area on the east coast of India.

Cage experiments at the discharge area of Madras Atomic Power Station (MAPS) facilitated studies of thermal tolerance in Emerita asiatica. At the laboratory, oxygen consumption at various temperatures and varying salinities was also investigated. In the field 100% mortality of crabs was recorded at the Condenser Cooling Water Pumps (CCWP) discharge site compared to no mortality at the Processed Sea Water Pumps (PSWP) site. This observation implicated temperature as a stress factor at the CCWP outfall, because other factors, including residual chlorine and water velocity, were the same at the PSWP and CCWP sites. Laboratory experiments on tolerance revealed that 38.5 degrees C was lethal to mole crabs. The time taken for 100% mortality decreased as the temperature increased from 35 to 40 degrees C. Oxygen metabolism showed a progressive increase with temperature from 29 to 36 degrees C, and declined at 37 degrees C. The influence of salinity on oxygen consumption was marginal at salinities of 20 to 35 per thousand but, when reduced to 15 per thousand, the oxygen consumption declined. The present study thus indicates that temperature could be the lethal factor, determining the distribution of mole crabs near the power station, where water temperature can exceed 40 degrees C.

Journal Article↗
PubMed1995

Defective interleukin-2 R gene expression in gastric carcinoma patients.

Peripheral blood T lymphocytes from 15 patients with gastric carcinoma and 6 normal healthy controls were evaluated for Interleukin-2 R gene expression. Total RNA was extracted from T cell-enriched fractions of patients as well as from control peripheral blood lymphocytes, with or without mitogenic stimulation. The presence of mRNA for IL-2 R alpha evaluated by Northern blot analysis revealed that unstimulated T cells expressed lower levels of IL-2 R mRNA than PHA stimulated T cells. Expression of both IL-2 R alpha transcripts (3.5 and 1.5 Kb) were either not detectable or only weakly detectable on T lymphocytes from patients even after mitogenic stimulation. In contrast, a significant rise in the expression of both IL-2 R alpha transcripts was observed on T cells from normal controls followed by mitogenic challenge. This paper reports on the defective IL-2 R alpha gene expression in gastric carcinoma patients, which may explain one of the causes of immunodeficiency associated with neoplastic transformation and progression.

Carcinoma↗
PubMed1994

A multiple fission-like mode of asexual reproduction in Blastocystis hominis.

A non-axenic and an axenic isolate of Blastocystis hominis have been induced to form cysts in vitro using an encystation medium. The morphology of the parasite at different time points was observed by scanning electron microscopy. In day-2 cultures the cysts were spherical and had a non-uniform, coarse outer surface around the body. A deep, pore-like opening was seen in some of the parasites. Most of the cysts from day-4 and day-6 cultures ruptured, revealing small, uniformly sized spherical bodies occurring in grape-like clusters. Acridine orange staining confirmed that these bodies were the progeny of Blastocystis hominis. A multiple fission-like reproduction process giving rise to many daughter Blastocystis occurs within the cyst.

Acridine Orange↗
PubMed1994

Ultrastructural changes during in vitro encystment of Blastocystis hominis.

The morphological changes occurring in Blastocystis hominis at different time points following in vitro encystment were studied by electron microscopy. The following stages of the parasite were sequentially seen: (a) the amoebic form, which was irregular in shape, with a majority of the organelles being concentrated at the condensed cytoplasmic region; (b) the pre-cystic form, which was rounded and had an electron-dense material forming a homogeneous wall around the central body; and (c) the cystic form, which had a very prominent, thick osmiophilic electron-dense wall, within which there were many inclusions and possibly reproductive granules. The amoebic form appeared to be an intermediate stage between the vacuolar form and the pre-cystic form, as this stage allowed the parasite to ingest bacteria to enhance encystment. The pre-cystic stage had previously been shown in experimental infection to be infective. The role of the cystic stage in producing infection is currently being investigated.

Animals↗
PubMed1994

Differentiation of the various stages of Blastocystis hominis by acridine orange staining.

Acridine orange staining differentiates the cystic and the central body forms of Blastocystis hominis and offers a very convenient and easy method to observe the internal structure of the parasite. Acridine orange stains the nuclei and the central body of the rounded vacuolar forms of the parasite bright and dull green, respectively. The colour changes to yellow and then to flaming red-orange when the rounded central body forms of the parasite become cystic.

Acridine Orange↗
PubMed1994

Augmentation of murine natural killer cell and antibody dependent cellular cytotoxicity activities by Phyllanthus emblica, a new immunomodulator.

When administered orally, Phyllanthus emblica, an excellent source of vitamin C (ascorbate), has been found to enhance natural killer (NK) cell activity and antibody dependent cellular cytotoxicity (ADCC) in syngeneic BALB/c mice, bearing Dalton's lymphoma ascites (DLA) tumor. P. emblica elicited a 2-fold increase in splenic NK cell activity on day 3 post tumor inoculation. Enhanced activity was highly significant on days 3, 5, 7 and 9 after tumor inoculation with respect to the untreated tumor bearing control. A significant enhancement in ADCC was documented on days 3, 7, 9, 11 and 13 in drug treated mice as compared to the control. An increase in life span (ILS) of 35% was recorded in tumor bearing mice treated with P. emblica. This increased survival was completely abrogated when NK cell and killer (K) cell activities were depleted either by cyclophosphamide or anti-asialo-GM1 antibody treatment. These results indicate: (a) an absolute requirement for a functional NK cell or K cell population in order that P. emblica can exert its effect on tumor bearing animals, and (b) the antitumor activity of P. emblica is mediated primarily through the ability of the drug to augment natural cell mediated cytotoxicity.

Adjuvants, Immunologic↗
PubMed1993

In vitro encystment and experimental infections of Blastocystis hominis.

Cultures of Blastocystis hominis were induced to encyst using three encystation media: (a) an encystation medium (EM) comprising yeast extract in buffered saline containing 50% horse serum, (b) an encystation medium (CEM) comprising EM conditioned with bacterial soluble products and (c) an encystation medium (TEM) containing 0.5% trypticase in EM. Two isolates of B. hominis were studied, an axenized isolate C and a non-axenized isolate MS. In EM, isolate C did not encyst, whereas 6.1% of isolate MS had encysted by day 1. However, in CEM and TEM, 17.4% and 25.7% of isolate C, respectively, had encysted by day 5. In all three media, isolate MS encysted more readily than isolate C, with as much as 91.7% of the former encysting in TEM. As viewed by phase-contrast microscopy, cyst-like stages appeared highly refractile. Direct stool examination of juvenile Wistar rats infected with 10,000 cyst-like stages of both C and MS isolates showed Blastocystis at day 2 post-infection. At autopsy on day 7, large numbers of Blastocystis were seen in the cecum, with smaller numbers being observed in the large intestine. In contrast, rats fed with various inocula of the vacuolar stages of isolates C and MS did not become infected, indicating the importance of the encysted stages in the transmission of the parasite.

Animals↗
PubMed1993

Gliclazide in the treatment of obese non-insulin dependent diabetic patients.

The clinical efficacy of gliclazide and its effect on plasma glucose, body weight and serum lipids was assessed in a 3 months open trial of 30 obese, Non-Insulin Dependent diabetes mellitus (NIDDM) patients who failed to respond to diet therapy alone. By day 20, the mean post prandial plasma glucose (PPG), and fasting plasma glucose (FPG) were significantly reduced from 276 +/- 13.5 to 195.8 +/- 13.9 mg % (p < 0.01) and 179 +/- 9.3 to 130.6 +/- 9.6 mg % (p < 0.01) respectively. This early glycaemic control was maintained, and by 3 months a further significant decrease occurred in PPG to 156.46 +/- 7.6 mg % (p < 0.01), and FPG to 106.9 +/- 3.8 mg % (p < 0.01). Mean glycosylated haemoglobin (HbA1c) was reduced from 10.3% to 7.7%. The drug had a favourable effect on serum lipids, significantly increasing high density lipoprotein fraction of cholesterol (HDL-C) (p < 0.034), and decreasing low density lipoprotein fraction of cholesterol (LDL-C) (p < 0.049). Mean body weight showed a significant reduction of 1.5 kg (p < 0.003). We conclude that gliclazide is an effective hypoglycaemic agent that ensures a rapid and sustained blood glucose control with a favourable effect on lipids and body weight in obese NIDDM patients.

Blood Glucose↗
PubMed1991

A comparative study of X-ray pelvimetry and CT pelvimetry.

In this study 24 patients who had conventional erect lateral X-ray pelvimetry had a CT pelvimetry done after delivery to complete the pelvimetry views. The erect lateral pelvimetry was read independently by a Consultant Radiologist, Consultant Obstetrician and a Medical Officer training in Obstetrics and Gynaecology. Using CT pelvimetry as the 'gold standard' (as the error of measurement was known with the machine used) the 3 readings were compared. There was no statistical difference in the values suggesting that X-ray pelvimetry is comparable to CT pelvimetry. However CT pelvimetry is preferred, if available, because of the lower dose of radiation involved, more comfort for the patient and shorter time in performing the procedure. Measurements done are easily read directly from the CT console.

Adolescent↗