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S Maneesri

Publications and source records attributed to S Maneesri.

13 recordsLinked to original sources
PubMed2006

The relationship between neuropeptide Y expression and headache in pituitary tumours.

Patients with pituitary tumours often present with disabling headache but there is no clear relationship between tumour size and headache. Neuropeptide Y (NPY) has been identified in pituitary tumours and may serve as a biochemical marker of the propensity for headache. Using immunohistochemical techniques we examined 27 consecutive pituitary adenoma specimens for NPY (including one normal postmortem control anterior pituitary specimen). A separate observer divided the patients into two groups: headache and non-headache. The association between the presence of NPY and headache was tested. NPY positive immunoreactivity was seen in 13 tumour specimens (50%, 13 of 26 pituitary tumour specimens), characterized by cytoplasmic and nuclear staining patterns. There was no significant association between the presence of NPY and headache (chi(2) = 0.9, P = 0.34). We did not observe NPY in the normal anterior pituitary control specimen. NPY was present in four of five (80%) growth hormone-secreting tumours and two of two (100%) prolactinomas, compared with four of 11 (36%) non-functioning adenomas. The mechanism of many pituitary tumour-associated headaches remains undetermined. The significance of NPY positivity in pituitary tumours is unknown, although the results of this study may implicate this peptide in the control of somatotroph and lactotroph activity. Our data do not support a clear role for NPY pituitary tumour-associated headache.

Chi-Square Distribution↗
PubMed2004

The association between calcitonin gene-related peptide (CGRP), substance P and headache in pituitary tumours.

OBJECTIVES: To determine if the differential expression of calcitonin gene-related peptide (CGRP) or substance P (SP) in a range of pituitary tumours was related to the presence or absence of headache. METHODS: Using recognised immunohistochemical techniques we examined twenty-six consecutive pituitary adenoma specimens for the presence of CGRP and SP. We included one normal post mortem pituitary specimen for comparison. A separate observer divided the patients into two groups: headache and non-headache. The association between the presence of CGRP, SP and headache was observed. RESULTS: We observed CGRP in seven specimens (27%) and SP in six tumour specimens (23%), with cytoplasmic staining being the predominant morphological picture. CGRP and SP were co-expressed in the same tumour specimen in five cases. There was no significant association between the presence of CGRP and headache (chi(2) 0.86; P = 0.35). We did not observe CGRP or SP in the control specimen. There was no correlation between tumour subtype and the presence of CGRP or SP. CONCLUSIONS: The mechanism of pituitary tumour-associated headache remains undetermined. The significance of the presence of CGRP and SP in pituitary tumours is unknown but does not appear to be related to headache or endocrine activity of the tumour.

Acromegaly↗
PubMed2000

Hyposerotonin-induced nitric oxide supersensitivity in the cerebral microcirculation.

OBJECTIVE: To investigate the relationship between hyposerotonin and cranial microvascular responses to nitric oxide (NO). BACKGROUND: Although the mechanism underlying NO supersensitivity in migraine is still unclear, an alteration of the serotonin system is a possible explanation. METHODS: Wistar rats were divided into control and hyposerotonin groups. Serotonin was depleted by intraperitoneal injection with 300 mg/kg of para-chlorophenylalanine (PCPA), a tryptophan hydroxylase inhibitor. Three days after PCPA pretreatment, the animals were prepared for assessment of their NO-induced vasomotor response using glyceryl trinitrate (GTN: 8 to 10 mg/kg, intravenously) as an NO donor. Pial circulation was visualized by the intravital fluorescein videomicroscopic technique. Images of vessels at 0, 5, 15, 30, and 60 minutes post GTN infusion were digitized and measured. At the end of monitoring, the rat brains were removed for ultrastructural study of the brain microvessels. RESULTS: Infusion of GTN produced dose-dependent pial arteriolar dilatation. This vasodilator effect was significantly increased in the PCPA-treated groups, especially at 30 and 60 minutes. The percentage change from baseline diameter at 30 minutes after the 8-mg/kg GTN infusion was 42.6 +/- 3.1 for the hyposerotonin group and 16.8 +/- 2.9 for the control group (P<.001). Electron microscopic study revealed that exposure to the NO donor produced considerable changes in cerebral microvessels, characterized by focal ballooning of endothelial cells, increased microvillous formation, and increased endothelial pinocytosis. These anatomical changes were significantly more prominent in the hyposerotonin group. CONCLUSIONS: A hyposerotoninergic condition can facilitate the NO-induced physiological and pathological responses in meningeal and cerebral microvessels and, therefore, is a possible explanation for the supersensitivity to NO observed in patients with migraine.

Animals↗
PubMed1998

Derangement of serotonin system in migrainous patients with analgesic abuse headache: clues from platelets.

Accumulating evidence indicates that serotonin (5-HT) may be involved in the process of analgesic-induced headache transformation. In order to clarify this hypothesis, we investigated the 5-HT system in migraine patients with analgesic abuse headache by using platelets as a neuronal model. Our results revealed a significant decrease in platelet 5-HT content in these patients compared to migraine patients and nonheadache controls (179.24 +/- 10.18, 451.22 +/- 14.35, and 480.22 +/- 13.98 ng/10(9) platelets, respectively; P < 0.001). This biochemical result was well correlated with a significant decrease (P < 0.001) in platelet dense body number observed in these patients (5.9 +/- 0.4 and 9.2 +/- 0.6 granules/10 platelets. For migraine patients with and without analgesic abuse headache, respectively). Beside the 5-HT depletion, the presence of numerous large intracytoplasmic vacuoles formed from the surface-connecting canaliculi system was found in this condition. Such a finding has not been previously described. The total area occupied by these vacuoles was significantly greater (P < 0.01) in migraine patients with analgesic overuse than in migraine patients and nonheadache controls (249.2 +/- 19.5, 164.1 +/- 19.5, and 183.1 +/- 20.3 nm2/cells, respectively). As this canaliculi system plays a significant role in the platelet secretory response, such dilatation may imply an excessive release of substances from this system. Based on this platelet model, we suggest that excessive use of analgesics alters the central 5-HT system by depleting 5-HT from its storage sites and results in the hyposerotonergic state. This analgesic-induced 5-HT alteration may be a possible mechanism of headache transformation observed in this condition.

Adult↗
PubMed1998

Effects of Russell's viper venom on human erythrocytes in vitro.

The effects of Russell's viper venom (RVV) on human erythrocytes were studied in vitro with respect to packed cell volume (hematocrit), the erythrocyte morphology, and the effect of antivenom. Venom at various dosages ranging from 50 ng to 120 micrograms increased hematocrit significantly. The maximal effect was detected at 800 ng of venom. The biconcave erythrocytes shown by scanning electron microscopy became sphero-echinocytes. Such altered morphology was observed immediately at 1 minute and reached maximum at 30 minutes. The mild degree of erythrocyte deformation was observed at 60 and 120 min with 100 ng of RVV. There were no morphologic changes when ethylenediaminetetracetate (EDTA) was used as an anticoagulant or when plasma was substituted by isotonic saline, acetar, albumin added acetar solution. Phospholipase A2 at equivalent dose as compared to the venom could also produce the sphero-echinocytosis. The phospholipase A2 inhibitor, p-bromophenacyl bromide markedly reduced the degree of RVV induced sphero-echinocytosis. Verapamil, a phenylalkylamine calcium channel blocker, could not prevent the RVV induced sphero-echinocytosis. Although antivenom could not reverse the RVV induced sphero-echinocytosis, it minimized these effects. The RVV induced sphero-echinocytosis is likely caused by phospholipase A2. Calcium and some plasma factors are required for this process. Early treatment with antivenom plays some role in prevention of RVV induced sphero-echinocytosis which may reduce hypoxic cell injury.

Animals↗
PubMed1997

Moderately differentiated neuroendocrine carcinoma (atypical carcinoid) of the larynx.

A moderately differentiated neuroendocrine carcinoma or atypical carcinoid of the larynx occurred in a 68-year-old woman who developed rapidly progressive dysphagia, hoarseness and a neck mass. Immunohistochemical and electron microscopic studies verified the nature of this tumor. Local invasion and distant metastases are common. It is suggested that cigarette smoking could increase the risk of developing this neoplasm.

Aged↗
PubMed1996

Primary ovarian carcinoid: a mixture of insular, trabecular and mucinous components.

A case of primary ovarian carcinoid in a 53-year-old woman is described. The tumor which replaced the left ovary showed a mixture of insular, trabecular and mucinous cell types in the same mass. The nature of the neoplastic cells has been verified by light and electron microscopic studies. The latter investigation demonstrated bundles of tonofilament and apical villi of the trabecular cells in addition to the morphologic difference of neurosecretory granules among these various cells.

Carcinoid Tumor↗
PubMed1995

Calcified cystic pituitary prolactinoma.

An unusual cystic pituitary prolactinoma in a 20-year-old man is described. The tumor was roentgenographically calcified. Ultrastructurally, the calcium deposits were found within the cytoplasm of tumor cells, extracellular spaces and blood vessels. The mechanism of intratumoral calcification is discussed in relation to degeneration of neoplastic cells and reparative process.

Adult↗
PubMed1995

Adenosquamous carcinoma of the thyroid: a case report and review of the literature.

A case of mixed squamous cell carcinoma and papillary adenocarcinoma of the thyroid in a 75-year-old woman is described. Review of 19 reported adenosquamous carcinoma including the present case revealed that they tended to occur in the sixth and seventh decades of life with an average age of 63.84 years and without sexual predilection. Local invasion and metastases of this highly fatal neoplasm are common.

Aged↗
PubMed1995

Mucin-producing malignant meningioma with papillary and glandular patterns.

An exceedingly rare intracranial malignant meningioma with papillary and glandular patterns in a 45-year-old man is described. Intracellular mucin production was demonstrated. The nature of the neoplastic cells was verified by immunohistochemical and electron microscopic studies.

Adenocarcinoma, Mucinous↗
PubMed1994

Congenital hemihypertrophy with adrenocortical adenoma.

A rare case of adrenocortical adenoma in a 7-month-old female infant with congenital hemihypertrophy of left leg is described. Only 7 similar cases including the present one, are on record. The patients ranged in age from 7 weeks to 45 years. The male:female ratio was 3:4. The adrenal tumors were often detected after CH had become evident. Large functional tumors often produced symptoms of hirsutism, virilization, and precocious puberty. CT and ultrasound are necessary for early detection and prompt treatment.

Adrenal Cortex Neoplasms↗
PubMedDate not supplied

Comparative effects of garlic and aspirin on diabetic cardiovascular complications.

By using streptozotocin-induced diabetic rats as a studied model, our previous experimental results have indicated that daily oral feeding of garlic extract (100 mg/kg BW) could increase the cardiovascular functions in streptozotocin (STZ) rats; the abnormality of lipid profile was prevented; and garlic extract could increase fibrinolitic activities with the decrease of platelet aggregation. Moreover, the plasma insulin level was increased concomitantly with the decrease of plasma glucose level. However, due to the high incidence of atherosclerosis in diabetes, the present study has been continued for further investigation of the effect of garlic extract on the coronary vascular ultrastructural changes. In addition, to identify the possible mechanism(s) of garlic's therapeutic effects, the cyclooxygenase inhibitor, aspirin, has been included in this present study. By using transmission electron microscopic studies, 16 weeks of daily oral feeding of garlic extract (100 mg/kg BW) caused as an antiatherosclerotic agent at the coronary arteriolar (15-30 microns) wall in STZ-rats. Interestingly, the thickening of coronary capillary (5-10 microns) basement membrane also was significantly attenuated within the group of STZ-rats treated with garlic extract. However, the possible direct action of garlic through the cyclooxygenase pathway has not been confirmed by the results of aspirin: The daily oral feeding of aspirin (10 mg/kg BW) in 16-week STZ-rats has not showed reduced arteriolar vascular wall abnormalities. The irregular patterns of fiber matrix, arranging the basement membrane at the arteriolar walls, were still recognized in the same manner as in STZ-rats. Interestingly, the thickening of the capillary basement membrane occurred in 16-week STZ-rats seems to be attenuated by the aspirin received. At present, garlic extract may open the new era in the medicinal use of garlic to prevent diabetic cardiovascular complications.

Animals↗