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Biomedical subjects

M K Basu

Publications and source records attributed to M K Basu.

At least 55 records · Page 3Linked to original sources

Synovial fluid glycosaminoglycan (acid mucopolysaccharide) analysis in assessment of temporomandibular joint dysfunction. A pilot study.

Temporomandibular joint (TMJ) synovial fluid was aspirated from normal control subjects and patients undergoing surgery for TMJ dysfunction. The glycosaminoglycan (GAG) composition of this fluid was analysed and compared with the clinical diagnosis and histological appearance of the condylar tissues. Changes in GAG composition were observed where a histologically hyperplastic response was seen in joint tissues, but these findings did not necessarily correlate with the initial clinical diagnosis. It is suggested that the fluid composition reflects the current metabolic activities of the tissues and may provide a useful marker of such processes.

Adult↗

Elastic cartilage in the incisive canal region: report of a case.

A man complained persistently of 'gritty bits' coming into his mount from behind the upper front teeth over a period of 10 years. Elastic cartilage was found within fibrous connective tissue of the incisive papilla region and it is suggested that transepidermal elimination of elastotic material, as happens in perforating dermatoses, was responsible for this patients complaint.

Cartilage↗

Mast cells in human odontogenic cysts.

Mast cells have been shown to be present in substantial numbers in both nonkeratinizing and keratinizing odontogenic cysts and could be seen in the connective tissue capsule and the epithelial lining. Within the cyst capsule, mast cells were more prevalent just beneath the epithelium than in deeper areas. This distribution pattern for mast cells is in accord with the histochemical picture for heparin staining in odontogenic cysts. In the non-keratinizing cysts, there appeared to be some trend towards mast cells being associated with increasing inflammation but not in the odontogenic keratocyst. No evidence could be found for distinct mast cell subpopulations in odontogenic cysts. The presence of mast cells in odontogenic cyst could contribute to their pathogenesis in several ways.

Cell Count↗

Leishmania donovani: superoxide dismutase level in infected macrophages.

Superoxide dismutase (SOD), a metal containing enzyme is present in parasite Leishmania donovani as well as in host macrophages both resident and activated in a detectable amount, although the level is much higher in the latter case. It is observed that at any particular protein concentration, the SOD activity is highest in the case of parasite infected macrophages and lowest in the case of normal resident macrophages; the SOD activity of thioglycolate activated macrophages lies in between the two. It is also noticed that formalin-killed Leishmania donovani neither attach to macrophages nor do they increase the SOD activity of the host. Thus, the processes, e.g. attachment of the parasite to the host membrane, subsequent membrane perturbation and thus activation of membrane bound enzyme NADPH oxidase leading to respiratory burst, may be responsible for an enormous increase in the SOD level in macrophages during infection. Moreover, the chemical nature of the SOD found in infected macrophages has been investigated by using an inhibitor, e.g. NaCN, which specifically inhibits Cu-Zn SOD but not Fe-SOD. A considerable inhibition of SOD activity by NaCN in infected macrophages confirms the chemical nature of the increased SOD to be of Cu-Zn type, usually found in host. Presumably, Cu-Zn SOD or host SOD plays a protective role at the time of parasite infection although the role of parasitic SOD or some other mechanisms for the survival of the parasite within the toxic phagolysosome environment of the macrophage cannot be ruled out.

Animals↗

Leishmania donovani: role of microviscosity of macrophage membrane in the process of parasite attachment and internalization.

Host macrophage infection by the parasite Leishmania donovani is heterogeneous, but it is not clear which factors are responsible for parasite recognition within the macrophages. One possible factor may be the alteration of the microviscosity of the macrophage membrane. This in turn may affect receptor expression and hence parasite infection. In this paper we describe alteration of the lipid composition and hence the microviscosity of the macrophage membrane in a controlled manner using liposome fusion technique. At a higher macrophage membrane microviscosity a larger number of parasites have been found to adhere to the macrophage surface. However, the proportion of parasites finally internalized when compared to parasites adhering to macrophages is inversely correlated with the artificially altered macrophage membrane microviscosity. The process of endocytosis has been examined in both native and lipid modified macrophages in the presence of several sugar antagonists. The results indicate (i) glucose and mannose are specifically involved in the binding process, and (ii) the microviscosity has a key role in controlling the macrophage parasite interaction. The results obtained so far support a model of endocytosis where expression of the receptor is a critical initial process dependent on the microviscosity of the membrane.

Animals↗

Phospholipids from the hepatopancreas of Indian horseshoe crab Carcinoscropius rotundicauda.

Total phospholipids were extracted from the heart, hepatopancreas, and hemolymph of the Indian horseshoe crab Carcinoscorpius rotundicauda by the conventional method. Characteristic group reaction and 2-dimensional thin-layer chromatography on silica gel were used for identification of different phospholipids. The phospholipid profile obtained from hemolymph and 2 major organs are comparable and show phosphatidyl choline (PC) and phosphatidyl ethanolamine to be the major phospholipids. A phospholipid has been consistently detected migrating immediately below the PC in the thin-layer chromatogram of lipids extracted from the hepatopancreas. When mixed methyl esters of this slower moving PC are resolved on a silica gel plate ran in hexane ether:acetic acid 80:20:1, with appropriate controls, an additional spot is seen just below the normal methyl ester, indicating a difference between the fatty acid compositions of 2 PC (e.g., regular and slower). The slower mixed methyl esters were found to comprise mainly the 4 saturated fatty acids: lauric, myristic, palmitic, and stearic. The slow moving PC seems to consist mainly of molecular species with the above-mentioned saturated fatty acids at both Sn 1 and Sn 2 positions.

Animals↗

The post-operative maxillary cyst. Experience with 23 cases.

23 cases, diagnosed as post-operative maxillary cyst, from outside Japan are described. Clinical, radiographic and histopathological features are not dissimilar to those cases reported from Japan, and various parameters have been found to be helpful in diagnosis. This lesion is more common outside Japan than previously suggested, and this is probably largely due to faulty diagnosis.

Adult↗

Dark-field microscopy of subgingival plaque microflora in Indian and English subjects.

This present investigation reports on the microbial pattern of subgingival plaque from English and Indian subjects living in the West Midlands of England. Subgingival plaque from healthy and diseased sites was studied using darkfield microscopy. The results indicate that significant differences exist in microbial flora of clinically normal and diseased sites of English as well as Indian subjects. Coccoid cells predominated in healthy sites, with an increase of 21% in the spirochaetes in diseased sites. The ratio of non-motiles to motiles was 1:0.6 in healthy sites, whereas in diseased sites the ratio observed was 1:1.8 in English subjects and 1:3.6 in Indian subjects. Comparison of healthy sites in Indians with healthy sites in English subjects revealed significant differences between numbers of rods (p less than 0.05). Comparing diseased sites of Indians with diseased sites in English subjects revealed significant difference between both cocci (p less than 0.05) and motile rods (p less than 0.01). A positive correlation between chronic inflammatory periodontal disease and spirochaete burden, and a negative one between the disease and coccal burden, was found.

Adult↗

Oral application of insulin encapsulated liposomes.

125Iodine labelled insulin encapsulated liposomes were introduced orally to rats. After different intervals of feeding, blood from the portal vein and heart was collected. The plasma was passed through a Sepharose 2B column to establish the presence of liposomes or intact hormone. Liposomal and hormonal fractions from the column loaded with plasma from the portal vain contained radioactivity. It was found that approx. 60% of the loaded radioactivity was associated with the liposomes whereas 20% of the loaded count was found with the hormonal fractions. It is noted that undegraded protein is not detected in portal plasma from rats fed with free insulin. When plasma from the heart of rats fed with liposomal insulin was passed through Sepharose 2B column, neither liposomes nor insulin was detected.

1,2-Dipalmitoylphosphatidylcholine↗

Plant glycosides in a liposomal drug-delivery system.

Plant glycosides were incorporated into the liposomal surface to study their sugar-specific uptake by various tissues. Two steroid glycosides, namely floribundasaponin D, with rhamnose as terminal sugar, and gracillin, with glucose and rhamnose as end sugars, were selected for the purpose. 125I-human IgG encapsulated liposomes composed of egg lecithin (phosphatidylcholine), cholesterol, dicetyl phosphate (optional) and either floribundasaponin D or gracillin, when injected into the tail vein of rat, showed significantly higher uptake in the rat liver than in appropriate controls. Whereas the uptake of floribundasaponin D liposomes was observed to be non-specific, the increased uptake of the gracillin liposomes, as judged from the inhibition studies with asppropriate sugars, was specific for glucose, although the receptor was unable to distinguish between the alpha and beta anomers ('anomerically blind'). The liver-perfusion studies showed that the uptake of gracillin liposomes was mostly by non-parenchymal cells.

Animals↗

Suppression of liver uptake of orally fed liposomes by injection (i.p.) of dextran sulfate 500.

125Iodine labelled human immunoglobulin-G encapsulated liposomes were administered orally to rats. Distribution of radioactivity was checked in various tissues and in portal blood. The effect of dextran sulfate (DS 500,000 m. wt., liver blockade agent) injection (i.p.) on the liver uptake of liposomes and on the amount of liposomes appearing in the portal blood from the gastrointestinal tract have been studied. An increased amount of radioactivity was observed in the portal blood and the amount of radioactivity in the liver decreased appreciably after injection of dextran sulfate. In both the cases the action of dextran sulfate started 2 hours after injection and reached maximum at 12 hour, falling slightly at 24 hour.

Administration, Oral↗

Evaluation of replica techniques for the surface ultrastructure of rodent and human palatal mucosa.

Two replicating techniques currently used for scanning electron microscopy were investigated qualitatively and quantitatively. The most accurate and reliable replicating material was an epoxy resin; this was superior to copper plating as the model material, despite some dimensional inaccuracies. The selected method was then used to obtain accurate elastomeric replicas of rodent and human palatal mucosa. Salivary-duct openings, epithelial cell boundaries, desquamating cells and cell-surface micropits were identified. In some areas, coccal organisms could be seen colonizing the epithelial surface.

Adult↗

Macrophages in oral lichen planus.

The presence and distribution of macrophages within 15 non-ulcerated lesions of oral lichen planus was investigated using an immunoperoxidase technique for the detection of the macrophage markers lysozyme and alpha 1 antitrypsin. All specimens contained mononuclear lysozyme and alpha 1 antitrypsin positive cells which were concentrated in a band immediately beneath the epithelium and often associated with areas of damaged basal cells. Cell counts revealed that 11% of the positive cells were in the epithelium and 89% in the lamina propria. Approximately 61% of all positive cells were found within a 125 micron wide zone centred on the basement membrane. These results suggest that in oral lichen planus macrophages are in close proximity to the epithelial basal cells, where cell damage occurs, and play a role in the pathogenesis of this condition.

Cell Count↗

Immunoglobulin-containing cells in normal human labial salivary glands.

The distribution of immunoglobulin-containing cells within 8 normal human labial salivary glands was studied using an immunoperoxidase technique. Cell counts revealed that IgA-containing cells pre-dominated in all specimens and that the mean percentage class ratios for IgG:IgA:IgM:IgD cells were 4:92:3:1. IgE cells were rare and only detected in one gland. The density of IgA cells (191 cells/mm2 of labial gland section) was greater than those previously reported for the parotid and submandibular glands. These results support the view that minor salivary glands play an important role in the synthesis and secretion of salivary antibody.

Adult↗

Changes in salivary peroxidase activity observed during experimentally-induced gingivitis.

Gingivitis was experimentally induced in 8 human subjects using an acrylic overlay to cover the teeth in the experimental area during any oral hygiene procedures. The overlays were used for a period of 3 weeks, after which the subjects received a scale and polish and then practised normal oral hygiene. At regular intervals during the experimental period, mixed saliva was collected for assay of peroxidase activity by spectrophotometric and test-strip procedures and plaque and gingival indices were assessed clinically. A considerable increase in peroxidase activity was observed during the experimental period, which declined after normal hygiene was resumed. This procedure may allow assessment of the progression of gingivitis under experimental conditions.

Adolescent↗

Calcifying epithelial odontogenic tumour: a case showing features of malignancy.

A case of malignant calcifying epithelial odontogenic tumour is reported in a 75-year-old man. Evidence of local tissue invasion and lymph-node metastasis is presented. Immunoperoxidase studies of the neoplastic cells and tumour amyloid were negative for a variety of antigens, including the epithelial markers CEA and keratin. The histological and clinical findings are discussed.

Aged↗