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Mast cells are traditionally known for mediating allergic reactions. In addition, these cells have been implicated in the
pathogenesis of a variety of clinical conditions such as atopic and contact dermatitis, bullous pemphigoid, fibrotic lung
disease, neurofibromatosis, psoriasis, scleroderma, rheumatoid arthritis, interstitial cystitis, ulcerative colitis, and Crohn’s
disease, but their role in host defense was an enigma until recently. Owing to the strategic location of mast cells at the
host environment interface, their role in bacterial infections has been studied by a number of investigators. Latest reports
show that mast cells have an ability to modulate the host’s innate immune response to infectious agents. This review discusses
the clinical implications of mast cell-bacteria interactions.
Received: 13 August 1997 / Accepted: 7 April 1998 相似文献
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Bhattacharya Salil K. Rao Patchala J. Mohan Bhattacharya Dipankar 《Pharmaceutical research》1984,1(5):229-231
Prostaglandin E1 (PGE1) produced dose-related catalepsy in rats when administered intracerebroventricularly. PGE1 induced catalepsy was significantly inhibited after pretreatment with pharmacological agents known to attenuate central serotonergic and cholinergic activity. It was also inhibited by PGF2 and naloxone. On the contrary, treatments enhancing central dopaminergic activity also reduced the cataleptic effect of PGE1. The results suggest that PGE1 induces catalepsy in rats by modulating activity of central neurotransmitters. 相似文献
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The selectivity of different external binding sites for quaternary ammonium ions in cloned potassium channels 总被引:1,自引:0,他引:1
W. Jarolimek K. V. Soman M. Alam A. M. Brown 《Pflügers Archiv : European journal of physiology》1995,430(5):672-681
Tetraethylammonium (TEA) is thought to be the most effective quaternary ammonium (QA) ion blocker at the external site of K+ channels, and small changes to the TEA ion reduce its potency. To examine the properties of the external QA receptor, we applied a variety of QA ions to excised patches from human embryonic kidney cells or Xenopus oocytes transfected with the delayed rectifying K+ channels Kv 2.1 and Kv 3.1. In outside-out patches of Kv 3.1, the relative potencies were TEA > tetrapropylammonium (TPA) > tetrabutylammonium (TBA). In contrast to Kv 3.1, the relative potencies in Kv 2.1 were TBA > TEA > TPA. In Kv 3.1 and Kv 2.1, external tetrapentylammonium (TPeA) blocked K+ currents in a fast, reversible and, in contrast to TEA, time-dependent manner. The external binding of TPeA appeared to be voltage independent, unlike the effects of TPeA applied to inside-out patches. External n-alkyl-triethylammonium compounds (C8, C10 chain length) had a lower affinity than TEA in Kv 3.1, but a higher affinity than TEA in Kv 2.1. In Kv 3.1, the decrease in QA affinity was large when one or two methyl groups were substituted for ethyl groups in TEA, but minor when propyl groups replaced ethyl groups. Changes in the free energy of binding could be correlated to changes in the free energy of hydration of TEA derivatives calculated by continuum methodology. These results reveal a substantial hydrophobic component of external QA ion binding to Kv 2.1, and to a lesser degree to Kv 3.1, in addition to the generally accepted electrostatic interactions. The chain length of hydrophobic TEA derivatives affects the affinity for the hydrophobic binding site, whereas the hydropathy of QA ions determines the electrostatic interaction energy. 相似文献
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Background. Prevalence of type 2 or non insulin dependent diabetes mellitus is high among Indians living in India as well as abroad. Prevalence among persons of Indian origin in many countries is greater than that of people of other ethnic extraction. The Indian state of Kerala is distinguished by a high level of achievement in the health sector, characterised by both lower mortality rates and greater density of health care institutions that ensure access to most people. These attributes make the prevalence of diabetes and the pattern of its management in Kerala worth studying. Objective. To estimate the prevalence of diabetes among persons 20 years or older in an urban housing settlement in Trivandrum city, the capital of Kerala, as well as study the management of the disease in subjects affected. Design. Cross sectional survey for detecting diabetes and other chronic diseases in all willing residents of an urban housing settlement in Trivandrum, the capital city of Kerala, as part of a preventive campaign against lifestyle diseases. Fasting plasma glucose, serum triglycerides, cholesterol, height, weight and blood pressure were measured, and a detailed questionnaire administered to ascertain previous diabetic status and management. Results. Overall prevalence of type 2 diabetes is 16.3%. In the 30-64 age group, age standardised prevalence is 13.7%. Gender differences in prevalence are negligible. Greater prevalence is associated with advancing age, body mass index above 24.99, sedentary habits, serum total cholesterol > 239, serum triglycerides > 149, hypertension and smoking. Compared to non-diabetics, diabetics have greater mean and range of fasting plasma glucose values (8.87 + /-3.6 mM/l as against 4.34 + /-0.53 mM/l). 32 out of 38 diabetics among the subjects (82.4%) were already diagnosed even before the survey; of them, 89% were on medication. 3% of subjects had impaired fasting glucose, or FPG level between 110-125 mg/dl. Conclusion. Prevalence of type 2 diabetes among a group of urban residents in Trivandrum city in Kerala is very high. This is associated also with a high detection rate and compliance to treatment. 相似文献
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K. Salil Kumar P. Muraleedharan Nampoothiri M. Venugopal P. Padmanabhan 《Indian journal of otolaryngology and head and neck surgery》2004,56(4):295-296
Esthesioneuroblastoma is an uncommon malignant neoplasm of nose and paranasal sinuses. Esthesioneuroblaslvma presenting as a collision tumour is very rare. The case of such a rare presentation is being reported here in a patient with previous history of squamous cell carcinoma uvula, post irridiatted; who now developed a bleeding nasal mass which proved to be a collision timour c ontaining both squamous cell carcinoma and Esthesioneuroblastoma on biopsy. 相似文献
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Assist. Prof. Balamurugan Vellayappan Dennis Cheong Salil Singbal Jeremy Tey Yu Yang Soon Cheng Nang Leong Alvin Wong Sein Lwin Chau Hung Lee Pravin Periasamy Simon Lo Naresh Kumar 《Radiology and oncology》2022,56(4):525
BackgroundThe primary objective was to quantify changes in vascular micro-environment in spinal metastases (SM) patients treated with stereotactic body radiotherapy (SBRT) with multi-parametric dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI). The secondary objective was to study plasma biomarkers related to endothelial apoptosis.Patients and methodsPatients were imaged with DCE-MRI at baseline/1-week/12-weeks post-SBRT. Metrics including normalised time-dependent leakage (Ktrans), permeability surface product (PS), fractional plasma volume (Vp), extracellular volume (Ve) and perfusion (F) were estimated using distributed parameter model. Serum acid sphingomyelinase (ASM) and sphingosine-1-phosphate (S1P) were quantified using ELISA. Clinical outcomes including physician-scored and patient-reported toxicity were collected.ResultsTwelve patients (with varying primary histology) were recruited, of whom 10 underwent SBRT. Nine patients (with 10 lesions) completed all 3 imaging assessment timepoints. One patient died due to pneumonia (unrelated) before follow-up scans were performed. Median SBRT dose was 27 Gy (range: 24–27) over 3 fractions (range: 2–3). Median follow-up for alive patients was 42-months (range: 22.3–54.3), with local control rate of 90% and one grade 2 or higher toxicity (vertebral compression fracture). In general, we found an overall trend of reduction at 12-weeks in all parameters (Ktrans/PS/Vp/Ve/F). Ktrans and PS showed a reduction as early as 1-week. Ve/Vp/F exhibited a slight rise 1-week post-SBRT before reducing below the baseline value. There were no significant changes, post-SBRT, in plasma biomarkers (ASM/S1P).ConclusionsTumour vascular micro-environment (measured by various metrics) showed a general trend towards downregulation post-SBRT. It is likely that vascular-mediated cell killing contributes to excellent local control rates seen with SBRT. Future studies should evaluate the effect of SBRT on primary-specific spinal metastases (e.g., renal cell carcinoma).Key words: spine metastases, stereotactic body radiotherapy, DCE-MRI, endothelial apoptosis 相似文献
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