Biomedical subjects
Publications and source records attributed to R Naik.
The relationship of mast cells, nerves and fibrosis was studied in 50 cases of Appendix using simple histochemical technique. In the mucosa, the mast cell number was greater in the early stages of fibrosis. Both in the mucosa and submucosa mast cells were found closely associated with neural tissue. As the fibrosis increased this association between mast cells and neural tissue was retained only in the submucosa.
A retrospective analysis of 70 patients with metastatic cutaneous nodules, was conducted in the department of pathology, Kasturba Medical College, Mangalore. The available clinical records and histologic material of these cases were reviewed. In last few years fine needle aspiration cytology (FNAC) was being used as the main diagnostic tool. The commonest primary site of cutaneous metastasis in this study was gastro-intestinal tract (46.7%) in males and breast (32%) in females. Abdomen (including umbilical nodules) was found to be the most frequent site for metastatic cutaneous nodule.
Mast cells were counted in 50 axillary lymphnodes draining breast carcinoma and 50 other lymphnodes from various sites with different histological lesions. All the lymphnodes, except those with tuberculous lymphadenitis were associated with increase in the number of mast cells. Highest number of mast cells (mean 172.80/mm2) were found in filarial lymphadenitis and lowest in tuberculous lymphadenitis (mean 8.87/mm2). In the axillary lymphnodes draining breast carcinoma, higher mast cell count was observed in reactive nodes. As these lymphnodes showed micro-metastasis the mast cells gradually decreased in number, and with extensive metastasis only few mast cells were seen. On comparison, the reactive lymphnodes draining breast carcinoma and other reactive nodes, the latter were associated with more mast cells.
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The junctional mucosa of 49 colorectal carcinomas were studied for Paneth cell metaplasia. Twenty two cases (44.89%) showed Paneth cells in the junctional mucosa. The carcinomas were seen mainly in the age range of 51 to 60 years (38.4%) The occurrence of Paneth cell metaplasia was higher in the vicinity of tumours of ascending colon and in well differentiated grades of adenocarcinomas. This probably indicates the reactive host response in the junctional mucosa which is of better prognostic significance.
The effect of taurine on the different types of ionic currents appears to depend on [Ca]o and [Ca]i and may also vary accordingly to tissue or cell type studied. Using microfluorometry and Ca2+ imaging techniques, short-term exposure (5-10 min) of single heart cells to taurine was found to increase total intracellular free Ca2+ in a concentration-dependent manner. However, long-term exposure of heart myocytes to taurine was found to decrease both nuclear and cytosolic Ca2+ without significantly changing either nuclear or cytosolic Na+ levels, as measured by 3-dimensional Ca2+ and Na+ confocal imaging techniques. Long-term exposure to taurine was found to prevent cytosolic and nuclear increases of Ca2+ induced by permanent depolarization of heart cells with high [K]o. This preventive effect of taurine on nuclear Ca2+ overload was associated with an increase of both cytosolic and nuclear free Na+. Thus, the effect of long-term exposure to taurine on intranuclear Ca2+ overload in heart cells seems to be mediated via stimulation of sarcolemmal and nuclear Ca2+ outflow through the Na+-Ca2+ exchanger.
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Silver staining nucleolar organiser regions (AgNORs) were studied in 35 cases of melanocytic skin tumours. In the 23 cases of benign melanocytic naevi AgNORs per nucleus were between 1.06 and 3.43 with a mean of 2.05. In the 12 cases of malignant melanoma the AgNORs ranged from 4.26 to 10.66 (mean 7.43). Since statistically significant difference in AgNOR counts between benign and malignant melanocytic skin tumours was noted, this technique may serve as a useful adjunct to routine histopathology.
Two hundred appendices were studied for mucosal and submucosal mast cell counts. In histologically normal appendices mucosal mean mast cell count (47.63/sq mm) was more than submucosal mean mast cell count (44.27/sq mm). Those patients who were aged under 15 and above 46 years showed more mean mucosal mast cell count compared to others. In acute appendicitis both mucosal and submucosal mast cells were decreased and in subacute appendicitis their count was found to be intermediate between normal and acute appendicitis.
Fifty mastectomy specimens of carcinoma breast were studied for pattern of mast cell distribution in their axillary lymph nodes. When all axillary nodes were free of tumour, the mean mast cell count was 35.75/sq mm. In the metastatic node the mast cell count was inversely proportional to the amount of metastatic tumour. The mast cell number decreased (25.64/sq mm) as the metastasis developed in any of the enlarged axillary nodes. Their count diminished further (23.55/sq mm) as the amount of metastatic tumour increased in individual nodes and when tumour involved all enlarged nodes. Mean mast cell count was lowest (10.50/sq mm) in metaplastic carcinoma. The mast cells in metastatic nodes were found mainly at the edges of tumour deposits.
In the present study, Fluo-3 Ca2+ measurement and confocal microscopy techniques were used in order to localize cytosolic []c and nuclear []n free Ca2+ distribution in resting and spontaneously contracting single heart cells from 10-day-old chick embryos. In resting single cells, the concentration of Ca2+ in the cytoplasm was lower than that in the nucleus. Increasing cytosolic free Ca2+ from 100-1600 nM gradually increased [Ca2+]n with a maximum capacity near 1200 nM. Results from Fura-2 microfluorometry and Fluo-3 confocal microscopy suggest a potential cross talk between the increase of cytosolic free Ca2+ and the uptake and release of Ca2+ by the nucleus during spontaneous contraction of single myocytes. Calcium waves in spontaneously contracting cells were found to spread from one cell to the next with the nucleus acting as a fluorescent beacon in which Ca2+ levels remained elevated for several milliseconds even after cytosolic Ca2+ had returned to near basal values. These results strongly suggest that the nucleus plays a negative and positive feedback role in controlling cytosolic free Ca2+ concentration during excitation-contraction coupling in heart cells.
Using the whole-cell voltage clamp technique, taurine was found to affect different types of various ionic currents including T and L-type Ca2+ currents, slow Na+ and fast Na+ currents as well as the delayed outward K+ current. Also, in normal situations, taurine had no effect on the Na(+)-Ca2+ exchange current. The effect of taurine on the different types of ionic currents appears to depend on [Ca2+]o and [Ca2+]i and may also vary according to the tissue or cell type studied. Using standard Ca2+ imaging techniques, short-term exposure (10 to 20 min) of single heart cells and aortic vascular smooth muscle cells was found to increase total intracellular free Ca2+ in a dose-dependent manner. However, using 3-dimensional Ca2+ and Na+ imaging techniques, long-term exposure of heart and vascular smooth muscle cells to taurine was found to decrease both nuclear and cytosolic Ca2+ without significantly changing either nuclear or cytosolic Na+ levels. Long-term exposure to taurine was found to prevent cytosolic and nuclear increases of Ca2+ induced by permanent depolarization of heart cells with high [K+]o. This preventive effect of taurine on nuclear Ca2+ overload was associated with an increase of both cytosolic and nuclear free Na+. Thus, the effect of long-term exposure to taurine on intranuclear Ca2+ overload in heart cells seems to be mediated via stimulation of sarcolemma and nuclear Ca2+ outflow through the Na(+)-Ca2+ exchanger.
OBJECTIVE: To study the effectiveness of follow up surveillance in detecting recurrent disease following radical hysterectomy for Stage IB cervical carcinoma. DESIGN: Retrospective analysis of clinical records using a computerised database. PARTICIPANTS: Six hundred and seventy-four patients with Stage IB carcinoma of the cervix underwent radical hysterectomy and lymph node dissection. INTERVENTIONS: Standard follow up surveillance consisted of clinical history and physical examination six weeks post surgery, and subsequently three monthly for the first year, six monthly for the second year, and yearly thereafter until 10 years post-treatment. RESULTS: Of the 674 patients, 112 (17%) developed recurrent disease. In only 29/112 (26%) was recurrent disease detected at the time of routine follow up visits. Nearly half of the patients (44%) were referred by their general practitioner between visits to the clinic because of suspicion of recurrent disease. CONCLUSION: Routine follow up surveillance is ineffective in detecting recurrent cervical carcinoma. Only one in four recurrences were detected at the time of a clinical visit.
In the present study 32 extragonadal tumours, reported in 38 years (1956 to 1994) from the department of pathology, Kasturba Medical College, Mangalore were analysed. These were seen predominantly in infants and children mainly affecting females. The commonest sites of these tumours were sacrococcygeal region (46.88%) followed by retroperitoneum and mediastinum. The rarest sites were mesentery, fallopian tube and suprasellar region in the cranial cavity. Histologically 27 out of 32 cases were teratomas, 75% of which were benign.
Hibernomas are uncommon, benign neoplasms of adipose composed of brown fat. A review of the world literature revealed about 115 cases. These tumors are asymptomatic and slow-growing, commonly seen in the the interscapular region. We herein present the third documented case of a scalp hibernoma.
A rare case of parathyroid cyst in a forty six-year-old lady diagnosed clinically as solitary thyroid nodule is reported. An intra-operative diagnosis of parathyroid cyst was made which was confirmed histopathologically. The clinicopathologic aspects, diagnostic methods and treatment modalities of this unusual condition are briefly discussed.