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Biomedical subjects

S Ramesh

Publications and source records attributed to S Ramesh.

At least 19 recordsLinked to original sources

Pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin after intramuscular administration of enrofloxacin in goats.

The pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin were investigated in goats after a single intramuscular administration of enrofloxacin at 2.5 mg/kg body weight. The plasma concentrations of enrofloxacin and ciprofloxacin were determined simultaneously by a HPLC method. The peak concentrations (Cmax) of enrofloxacin (1.13 microg/ml) and ciprofloxacin (0.24 microg/ml) were observed at 0.8 and 1.2 h, respectively. The elimination half-life (t1/2beta), volume of distribution (Vd(area)), total body clearance (Cl(B)) and mean residence time (MRT) of enrofloxacin were 0.74 h, 1.42 L/kg, 1329 ml/h per kg and 1.54 h, respectively. The t1/2beta, area under the plasma concentration-time curve (AUC) and the MRT of ciprofloxacin were 1.38 h, 0.74 microg h/ml and 2.73 h, respectively. The metabolic conversion of enrofloxacin to ciprofloxacin was appreciable (36%) and the sum of the plasma concentrations of enrofloxacin and ciprofloxacin was maintained at or above 0.1 microg/ml for up to 4 h. Enrofloxacin appears to be useful for the treatment of goat diseases associated with pathogens sensitive to this drug.

Animals↗

Wilms' tumor with vena caval, atrial, and middle hepatic vein tumor thrombus.

A 3-year-old male with a right-sided Wilms' tumor presented with tender hepatomegaly and bilateral lower-limb edema. Ultrasound and echocardiography showed a massive tumor thrombus completely occluding the inferior vena cava, right atrial cavity, and extending retrogradely into the middle hepatic vein. Two courses of preoperative chemotherapy (vincristine, actinomycin D, adriamycin) caused minimal shrinkage of the thrombus. The tumor and thrombus were successfully removed with the patient under cardiopulmonary bypass and deep hypothermic circulatory arrest followed by multiagent chemotherapy (vincristine, actinomycin D, adriamycin, cyclophosphamide). The child is alive and well with no evidence of disease 15 months later. Occlusion of the hepatic vein by a tumor thrombus in Wilms' tumor is a very rare event. It was completely removed by the right atrial route under direct vision in this child.

Antibiotics, Antineoplastic↗

Effects of endotoxin-induced fever and probenecid on disposition of enrofloxacin and its metabolite ciprofloxacin after intravascular administration of enrofloxacin in goats.

Pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin were investigated in normal, febrile and probenecid-treated adult goats after single intravenous (i.v.) administration of enrofloxacin (5 mg/kg). Pharmacokinetic evaluation of the plasma concentration-time data of enrofloxacin and ciprofloxacin was performed using two- and one-compartment open models, respectively. Plasma enrofloxacin concentrations were significantly higher in febrile (0.75-7 h) and probenecid-treated (5-7 h) goats than in normal goats. The sum of enrofloxacin and ciprofloxacin concentrations in plasma > or =0.1 microg /mL was maintained up to 7 and 8 h in normal and febrile or probenecid-treated goats, respectively. The t1/2beta, AUC, MRT and ClB of enrofloxacin in normal animals were determined to be 1.14 h, 6.71 microg .h/mL, 1.5 h and 807 mL/h/kg, respectively. The fraction of enrofloxacin metabolized to ciprofloxacin was 28.8%. The Cmax., t1/2beta, AUC and MRT of ciprofloxacin in normal goats were 0.45 microg /mL, 1.79 h, 1.84 microg .h/mL and 3.34 h, respectively. As compared with normal goats, the values of t1/2beta (1.83 h), AUC (11.68 microg ? h/mL) and MRT (2.13 h) of enrofloxacin were significantly higher, whereas its ClB (430 mL/h/kg) and metabolite conversion to ciprofloxacin (8.5%) were lower in febrile goats. The Cmax. (0.18 microg /mL) and AUC (0.99 microg .h/mL) of ciprofloxacin were significantly decreased, whereas its t1/2beta (2.75 h) and MRT (4.58 h) were prolonged in febrile than in normal goats. Concomitant administration of probenecid (40 mg/kg, i.v.) with enrofloxacin did not significantly alter any of the pharmacokinetic variables of either enrofloxacin or ciprofloxacin in goats.

Animals↗

Combined optical and fluorescence imaging for breast cancer detection and diagnosis.

In this article, we present a novel approach that combines the best aspects of both endogenous optical imaging and exogenous fluorescent lifetime and yield imaging for breast cancer detection and diagnosis. Using this approach, spatial distributions of optical properties, fluorescence lifetime, and yield in tissue can be reconstructed from measured excitation and emission data at the surface of the breast tissue by regularized inverse algorithms. We show images from simulated data, as well as images from experimental data using tissue-like phantom materials in the laboratory.

Algorithms↗

Influence of plant growth stage on the essential oil content and composition in Davana (Artemisia pallens wall.).

The influence of three plant growth stages (full emergence of flower heads, anthesis, and initiation of seed set) on the essential oil content and composition in Davana (Artemisia pallens Wall) was investigated over two successive seasons. The essential oil content was found to be higher at the full emergence of flower heads than at anthesis and initiation of seed set stages. The contents of davanone, the major constituent of davana oil, and linalool decreased while those of (Z)- and (E)-methyl cinnamate, (E)-ethyl cinnamate, bicyclogermacrene, davana ether, 2-hydroxyisodavanone, and farnesol increased from flower heads emergence stage to the initiation of seed set stage. These results support the general practice of harvesting the crop at full bloom stage. Five compounds, viz., (Z)- and (E)-methyl cinnamates, (Z)- and (E)-ethyl cinnamates, and geranyl acetate, were identified for the first time in davana oil.

Artemisia↗

Reduction in membranous expression of beta-catenin and increased cytoplasmic E-cadherin expression predict poor survival in gastric cancer.

beta-catenin, a component of the E-cadherin-catenin cell adhesion complex, also plays a separate intracellular signalling role, interacting with APC protein. Intracellular accumulation of beta-catenin is common in colorectal neoplasia. beta-catenin abnormalities are associated with poor survival in gastric cancer, but previous studies do not differentiate between membrane-associated and intracellular beta-catenin. In this study we aimed to determine which type of expression abnormalities for E-cadherin, beta-catenin and alpha-catenin correlate with clinico-pathological features and survival in gastric cancer. Immunoperoxidase staining of paraffin-embedded sections from 40 gastric cancers was performed for E-cadherin, alpha- and beta-catenins using microwave unmasking and an avidin-biotin technique. Clinical data were obtained from case records and cancer registry records. Reduced membranous expression of beta-catenin occurred in 10/12 (83%) diffuse and 8/28 (29%) intestinal tumours (P= 0.0014), and was associated with poor differentiation (P= 0.0015) and short survival (P= 0.032), but not with age, sex, tumour size or nodal status. Nuclear expression of beta-catenin was uncommon; cytoplasmic expression was observed in 13/40 cases (33%) but did not correlate with histology, tumour grade or survival. Reduced E-cadherin membrane expression was associated with lymph node metastasis (P= 0.02). Neither E-cadherin or alpha-catenin expression correlated with survival. Reduced membranous expression of beta-catenin predicts poor prognosis in gastric cancer, whilst ectopic intracellular expression is relatively rare. The apparent differences in beta-catenin expression from those found in colon cancer merit further study.

Cadherins↗

Open trial of intravenous immune serum globulin for chronic sinusitis in children.

BACKGROUND: Chronic sinusitis in children is a complex clinical problem. Some patients do not improve with medical therapy and some fail surgery as well. OBJECTIVE: A therapeutic trial of intravenous immune serum globulin (IVIG) was given to children whose sinus disease was recalcitrant to the usual therapeutic modalities. The objective of IVIG administration was to modulate the inflammatory process contributing to the chronicity of the sinusitis. METHODS: Six patients were given a 12-month trial of monthly (400 mg/kg) IVIG infusions. Entry criteria included persistence of sinusitis after 3 months of full course antibiotics, or two episodes of sinusitis within a 3-month period while on prophylactic antibiotics. All patients had abnormal sinus CT (computerized tomography) scans at entry. Three of the six patients remained symptomatic despite prior sinus surgery. Patients with primary immune deficiencies were excluded. Each patient served as his own control based on their previous 12-month history and clinical course. Four of the 6 patients were atopic as demonstrated by prick skin testing; however, all patients had nasal eosinophilia. RESULTS: Full course antibiotic use decreased in five of the six patients (183 to 84 days); correspondingly, the episodes of sinusitis decreased (average 9 to 4 per year). In addition, sinus CT scans showed significant improvement. CONCLUSION: This preliminary open-trial of IVIG suggests its usefulness as adjunct therapy to medical management in selected patients with chronic sinus disease. The mechanism(s) by which IVIG may be helpful is probably not based on the concept of replacement therapy, but more likely as an immune or inflammatory modulating agent.

Anti-Bacterial Agents↗

A traumatic deterioration in general surgeons access to emergency theatre.

An audit has been carried out of general surgical emergency theatre usage before and after the allocation of some of the emergency theatre time for trauma lists. The median delay between decision to operate and operation starting rose from 1 hour 15 minutes to 2 hours 30 minutes. There was a fall in the number of operations carried out during the day (p < 0.001) and a corresponding increase in the number of procedures performed after midnight (p < 0.005). Emergency theatre usage provides advantages to patient and surgeon alike. However, by its nature it will not be fully occupied all of the time. There is always likely to be a temptation to use some of the "free time' for non-emergency cases. This results in the advantages of the emergency theatre being lost.

Abscess↗

Theatre delay for general surgical emergencies: a prospective audit.

A prospective audit of emergency theatre use for general surgery has been undertaken. Two month periods were studied before and after the introduction of a fully staffed 24-hour emergency theatre. Data were collected using a proforma documenting the time of the decision to operate, the actual time of the operation and the reason for and duration of any delay. After the introduction of the facility the proportion of procedures performed after midnight fell from 29 cases (21.3 per cent) to 7 (6.3 per cent) (p < 0.05). Emergency operating between 0900-1700 hrs increased from 40 cases (29.4 per cent) to 71 (61.3 per cent) (p < 0.05). There was no significant difference in the causes of delay between the two groups, the commonest being queuing for theatre. However, the length of the delay was significantly reduced. That for an appendicectomy was reduced from a median of 4 hrs 40 mins (range 30 mins-18 hrs 45 mins) to 1 hr 29 mins (0-6 hrs 30 mins) (p < 0.01) and for drainage of abscess from 5 hrs 56 mins (15 mins-20 hrs 30 mins) to 1 hr 51 mins (0-4 hrs 30 mins) (p < 0.01). There was no significant difference in the seniority of the surgeon making the decision to operate. In the first part of the audit we identified problems with regard to delay which were addressed by the introduction of the emergency theatre. The audit cycle has been successfully closed improving the care of general surgical emergencies requiring urgent or emergency operations.

Emergencies↗

Extrarenal Wilms' tumour--a case report and review of literature.

Extra renal Wilm's tumour (EWT) is an exceedingly rare entity and needs to fulfill certain criteria. Of the 48 cases reported, only about 36 have been found to be convincingly proved. We present one more well proven case of EWT and have extensively reviewed the literature. The diagnostic, staging and management guidelines are discussed. Amongst the reported cases, the behaviour of the tumour appears to parallel that of similarly staged "intra renal" Wilm's tumour. Hence the staging and the management protocols of "intra renal" Wilm's tumour can well be applied to tumour of extra renal location albeit with some modifications.

Abdominal Neoplasms↗

The role of methotrexate in the management of steroid-dependent asthma.

Severe asthma often requires high-dose corticosteroid therapy. However, steroid therapy is fraught with many side effects. There are conflicting reports in the literature regarding the role of methotrexate in reducing the steroid requirements of these patients. This study examined the role of low-dose methotrexate in the management of steroid-dependent asthma. Eleven subjects with stable steroid-dependent asthma were enrolled in a placebo-controlled double-blind crossover trial. Patients received methotrexate, 15 mg/wk, or placebo each for two 12-week periods. There was significant improvement of pulmonary function and reduction of prednisone requirement in both placebo and methotrexate treatment periods. However, methotrexate was not superior to placebo. Only 3 of 11 patients responded to methotrexate. Although low-dose methotrexate therapy may have a role in a small select group of steroid-dependent asthmatics, it provided no additional benefit overall.

Adolescent↗

Early discharge from hospital after open appendicectomy.

A prospective study of 200 consecutive open emergency appendicectomies was carried out. All patients were informed before operation that they would be discharged the following day if possible. The operation was performed through a standard muscle-splitting incision. At the end of the operation the wound was infiltrated with bupivacaine and a diclofenac suppository was given. There were 29 normal, 129 acutely inflamed, six gangrenous and 36 perforated appendices. In all, 147 patients (73.5 per cent) were discharged home within 24 h and reviewed 2 weeks later. Twelve patients had seen their general practitioner, mainly for wound problems (eight) or pain (two). Two others required readmission. Thirty-four patients (23.1 per cent) required no postoperative analgesia; 104 (70.7 per cent) required paracetamol or co-proxamol for < or = 3 days and nine (6.1 per cent) for > 3 days. No patient had a problem directly related to early discharge from hospital. Fifty-three patients (26.5 per cent) were not discharged home early due to peritonitis (36), social reasons (seven), nausea (seven), associated caecal volvulus (one) and pregnancy (two). Early discharge from hospital within 24 h after emergency appendicectomy is safe and has good patient acceptability.

Adolescent↗

Popliteal aneurysm: morphology and management.

Since January 1988, 32 patients have presented with 44 popliteal aneurysms (22 thrombosed, 22 non-thrombosed). Patients with thrombosed aneurysms were older (median age 72 versus 66 years), and more likely to have bilateral lesions (P < 0.02) and serious associated cardiovascular disease (P < 0.02). Nineteen aneurysms thrombosed acutely; 12 were treated with intra-arterial thrombolysis, which was at least partially successful in seven. All 12 were subsequently bypassed, as were the other seven which were associated with such severe ischaemia that they required urgent operation. One patient died and two others required major amputation. Other complications included foot-drop (two patients), renal failure (one) and wound infection (two). Two grafts thrombosed and required re-exploration. Elective bypass was carried out in 11 patients without acutely thrombosed aneurysms; there were no significant postoperative problems. Distortion within the aneurysm (P < 0.01), large size (P < 0.01) and distortion of the popliteal artery above or below the lesion (P < 0.02) were all associated with thrombosis. Stenosis within the aneurysm was more likely in patients with multiple lesions (P < 0.01) and distortion with larger aneurysms (P < 0.01). After correcting for distortion, none of the other variables was independently significant. The combination of distortion and diameter > 3 cm was present in 13 of 15 thrombosed aneurysms. Morbidity is high following acute thrombosis of popliteal aneurysm. Distortion of the aneurysm appears to be a more sensitive predictor of thrombosis than size alone. The combination of distortion with a diameter > 3 cm may help to define popliteal aneurysms that should be bypassed electively.

Aged↗