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Biomedical subjects

A Saxena

Publications and source records attributed to A Saxena.

At least 91 records · Page 5Linked to original sources
PubMed2000

Oral ketamine for radiotherapy in children with cancer.

Children coming for radiotherapy under sedation usually get repeated injections, which cause distress to both the child and the parents. A prospective study was conducted to evaluate the efficacy of oral ketamine for sedation for radiotherapy (RT) in children with cancer. Ten children who received 49 sittings of RT were given 8-15 mg/kg body weight of oral ketamine. The onset time, recovery time, efficacy of sedation and incidence of abnormal movements were compared with another group of 8 children, who received intramuscular ketamine in the dose of 6 mg/kg for a total of 28 sittings of RT. Onset time and recovery time were significantly longer in oral ketamine group as compared to the intramuscular group (p < 0.001). Limb movements in patients receiving oral ketamine necessitated further supplement of sedation and interruption of RT. These drawbacks discourage use of oral ketamine as a good sedative for radiotherapy treatment in paediatric oncology patients.

Administration, Oral↗
PubMed2000

Diagnosis of rheumatic fever: current status of Jones Criteria and role of echocardiography.

The original Jones Criteria as proposed by Dr. T. Duckett Jones have been modified four times and the updated revised criteria were published in 1992. According to this latest publication major manifestations are carditis, polyarthritis, chorea, erythema marginatum and subcutaneous nodules. Minor manifestations include fever, arthralgia and laboratory findings of elevated erythrocyte sedimentation rate, C-reactive protein and prolonged PR interval on ECG. For making a diagnosis of acute rheumatic fever, two major, or one major and two minor manifestations must be accompanied by supporting evidence of antecedent group A streptococcal infection in the form of positive throat culture or elevated or rising anti-streptolysin titre. The updated guidelines also highlighted a subgroup of "exceptions to Jones Criteria" for patients with chorea, indolent carditis and previous history of rheumatic fever or "rheumatic heart disease". Role of echocardiography has not been defined in these modifications but may be important, as clinical detection of soft murmurs may be difficult due to tachycardia. Doppler and color flow mapping is more sensitive in picking up minor digress of valvular regurgitation. Several studies have confirmed that the yield of carditis with valvular regurgitation increased with use of echocardiography in patients with acute rheumatic fever. Also echocardiography is of great help in mixed valve lesions to determine the severity of each lesion. Other abnormalities detected on echocardiography in acute carditis include prolapse of the valve, focal nodular thickening of leaflets and pericardial effusion. Jones Criteria are guidelines to assist the physician and should not be substituted for clinical judgement as strictly following them may result in underdiagnosis of this disease in our country.

Biopsy↗
PubMed2000

Isolated congenital coronary arteriovenous fistula.

During the last eight years a total of nine cases of isolated congenital coronary arteriovenous fistula (CAVF) have been diagnosed at our centre. Age of these patients ranged from 11 days to 22 years (mean 6.4 +/- 4.2 years). There were seven male and two female patients. Right and left coronary arteries were the sites of origin in seven and three cases respectively. One patient had two fistulae, one each originating from right coronary artery and obtuse marginal artery. The drainage sites were right ventricle in seven cases and right atrium in two. The pulmonary artery pressure was normal in eight cases and elevated in one case. The pulmonary artery to systemic flow ratio ranged from 1.1:1-2.4:1 in all except the 11 day-old-baby in whom it was 4:1. Pulmonary vascular resistance (PVRI) was below 3.5 in all cases (range 1.0-3.5 units). Surgical ligation of fistula was done in four cases and two patients underwent coil embolisation of fistula. Follow-up is available in five out of eight patients including three cases in whom CAVF was closed. Two other young patients are being followed-up conservatively and all the patients are asymptomatic. CAVF can present at any age; majority of the cases have small left to right shunts and more commonly CAVF arise from right coronary artery. Surgical ligation of fistula is safe in older patients, non-surgical embolisation using coils may be an alternative to surgery in selected cases.

Adolescent↗
PubMed2000

Congenital diaphragmatic hernia "occulta".

Congenital diaphragmatic hernia usually presents with cyanotic attacks, dyspnoea and dextrocardia, a typical triad which is almost considered pathognomonic. The case records of 10 patients (out of a total of 20) of congenital diaphragmatic hernia presenting beyond the neonatal period were reviewed retrospectively. Age and symptoms at presentation and signs elicited were paid special attention. All the patients underwent operative repair of hernia under general anaesthesia. Given below is an explanation for such a high incidence of late presentation in our series. This nomenclature (Congenital Diaphragmatic Hernia "Occulta") will help clinicians in remembering this entity if and when such patients present to the clinicians.

Child↗
PubMed2000

Repair of a giant omphalocele by a modified technique.

Large omphaloceles that contain centrally herniated liver pose challenges to surgical closure, the most significant being the space limitation of the abdominal cavity. In addition, the "pedicled" nature of the liver on the inferior vena cava creates a predisposition to acute hepatic vascular outflow obstruction as the liver is reduced into the abdominal cavity. In such cases, the alternatives include conservative treatment or staged silo reduction. The worst complication of silastic silo (SS) placement is tension and infection of the fascia with disruption of the suture line. Once infection or premature disruption occurs, closure of the defect is difficult or impossible. This case report details a different management technique for a newborn with a giant omphalocele and presents an interesting variation of the usual SS technique that may be helpful in the management of some cases, especially in an emergency. The thick silk sutures applied in the present case absorbed the tension and the silastic sheet prevented the risks of infection and adhesions.

Abdominal Muscles↗
PubMed2000

Univentricular repair: is routine fenestration justified?

BACKGROUND: A decade after the introduction of baffle fenestration, the outcome of Fontan-type repair for hearts with a functional single ventricle finally looks promising. Our study was designed to assess the impact of fenestration on the outcome of univentricular repairs. METHODS: From January 1988 to December 1997, 348 patients (104 with tricuspid atresia and 244 with other morphological diagnoses) underwent univentricular repair at our institute. Since 1994, routine fenestration of the atrial baffle was performed in all patients (n = 126). RESULTS: The overall Fontan failure rate was 14% (50 of 348) and included 45 early deaths and five Fontan take downs. Absence of fenestration was the only and highly significant predictor of Fontan failure (risk ratio [RR] 3.3, 95% confidence interval [CI] 1.49 to 7.31, p = 0.002). Significant pleural effusion was seen in 27% of patients. Absence of fenestration of the atrial baffle (RR 3.97, 95% CI 2.17 to 7.26, p < 0.001) and aortic cross-clamp time more than 60 minutes (RR 2.15, 95% CI 1.3 to 3.5, p = 0.002) were found to be significant risk factors. The follow-up ranged from 6 to 120 months (mean 46.0 +/- 18.0 months). There were 12 late deaths and 5 patients were lost to follow-up. Actuarial survival (Kaplan Meier) at 90 months was 81% +/- 4%. Two hundred and fifty-eight patients (90%) were in New York Heart Association class I at their last follow-up visit. Oxygen saturation in the fenestrated group ranged from 85% to 94% (mean 89%). Thirty patients (26%) had spontaneous closure of the fenestration over a mean period of 34 months, and there has been no incidence of late systemic thromboembolism. In no instance has there been a need to close the fenestration. CONCLUSIONS: Elective fenestration of the intraatrial baffle is associated with decreased Fontan failure rate and decreased occurrence of significant postoperative pleural effusions. Routine elective fenestration of the atrial baffle may, therefore, be justified in all univentricular repairs.

Actuarial Analysis↗
PubMed2000

Right ventricular outflow tract after non-conduit repair of tetralogy of Fallot with coronary anomaly.

BACKGROUND: A total of 25 patients with tetralogy of Fallot and an important coronary artery crossing the right ventricular outflow tract underwent complete repair without use of an extracardiac conduit between January 1990 and December 1994. Repair was exclusively done by the transatrial or transatrial-transpulmonary approach. Age of these patients ranged from 1 to 12 years (mean 3.6 years). Three of the patients had already received a systemic to pulmonary artery shunt. METHODS: All patients reporting for follow-up (n = 18) were subjected to transthoracic echocardiography and, if required, cardiac catheterization and angiography. Right ventricle to pulmonary artery gradients were noted preoperatively, at discharge following repair and at follow-up study. RESULTS: Mean follow-up was 40.6 months (24 to 62 months). Mean early postoperative gradient was 23.5+/-13.4 mm Hg and 4 patients had significant (> 30 mm Hg) gradients. Mean late postoperative gradient was 20.6+/-12.4 mmHg and 2 patients had gradients greater than 30 mmHg. All the patients were in New York Heart Association functional class I at the time of last follow-up. CONCLUSIONS: Acceptable gradients across the right ventricular outflow tract are achievable following repair of tetralogy of Fallot in the presence of anomalous coronary artery across the right ventricular outflow tract using the transatrial or transatrial-transpulmonary approach. Most gradients were found not to vary significantly on subsequent follow-up.

Child↗
PubMed2000

Thoracic epidural anesthesia for modified radical mastectomy in a patient with cryptogenic fibrosing alveolitis: a case report.

A case of advanced cryptogenic fibrosing alveolitis (CFA) with multiple bullae and extensive pulmonary fibrosis, scheduled for modified radical mastectomy for carcinoma of breast, is presented. This patient had ischemic heart disease, corticosteroid-induced hypertension, diabetes mellitus, and a difficult airway. Thoracic epidural segmental anesthesia was successfully given to this patient. Preoperative problems, perioperative management, and alternative anesthetic techniques are discussed.

Anesthesia, Epidural↗
PubMed2000

Effects of intrathecal ketamine added to bupivacaine for spinal anaesthesia.

We prospectively studied 30 healthy female patients undergoing intracavitory brachytherapy applicator insertion for carcinoma of the cervix under spinal anaesthesia. Patients were randomly allocated to receive either intrathecal bupivacaine 10 mg alone or bupivacaine 7.5 mg combined with preservative-free ketamine 25 mg. Spinal block onset, maximum sensory level, duration of blockade, haemodynamic variables, postoperative analgesic requirements and adverse events were recorded. Onset of sensory and motor block and duration of spinal analgesia were comparable between groups. Duration of motor blockade was shorter (p = 0.0416) and requirement for intravenous fluids in the peri-operative period was less (p = 0.0159) in the ketamine group. Significantly more patients in the ketamine group had adverse events, such as sedation, dizziness, nystagmus, 'strange feelings' and postoperative nausea and vomiting. Although the addition of ketamine to spinal bupivacaine had local anaesthetic sparing effects, it did not provide extended postoperative analgesia or decrease the postoperative analgesic requirements. Moreover, the central adverse effects of ketamine limit its spinal application.

Adult↗
PubMed2000

Mycosis fungoides and chronic lymphocytic leukaemia--composite T-cell and B-cell lymphomas presenting in the skin.

Composite lymphomas involving cutaneous B-cell and T-cell lymphomas are very uncommon. We report here the unique circumstance of a patient with mycosis fungoides (primary cutaneous T-cell lymphoma) who later developed chronic lymphocytic leukaemia (B-cell lymphoproliferation, B-CLL), which presented in the skin (leukaemia cutis) as a composite lymphoma affecting an earlobe. The presence of both lymphoproliferative disorders was confirmed with immunophenotyping and the finding of both immunoglobulin gene rearrangements and T-cell receptor gene rearrangements in the ear and the same T-cell receptor gene rearrangement in a plaque lesion of mycosis fungoides on the arm.

Aged↗
PubMed2000

Field evaluation of the ICT malaria P.f/P.v immunochromatographic test for diagnosis of Plasmodium falciparum and P.vivax infection in forest villages of Chhindwara, central India.

A rapid new immunochromatographic test (ICT malaria P.f/P.v) for diagnosis of Plasmodium falciparum and P.vivax was evaluated against thick blood smears in forest villages of Chhindwara, Madhya Pradesh, where both Plasmodium falciparum and P.vivax are prevalent. 344 symptomatic patients (Gond ethnic tribe) in five villages were screened by field staff of the Malaria Research Centre in October 1999. For P.falciparum, the ICT was 97.5% sensitive and 88% specific, with a positive predictive value (PPV) of 87.6% and a negative predictive value (NPV) of 97.6%. For P.vivax the sensitivity was only 72%, the specificity 99%, with a PPV of 92% and an NPV of 96%. Although a negative test result was inadequate to exclude parasitaemia < or = 300/microl for P.falciparum and < or = 1500/microl for P.vivax, the test is potentially useful in remote areas.

Adolescent↗
PubMed2000

Acute hepatic failure in India: a perspective from the East.

Acute hepatic failure (AHF) in India almost always presents with encephalopathy within 4 weeks of the onset of acute hepatitis. Further subclassification of AHF into hyperacute, acute and subacute forms may not be necessary in this geographical area, where the rapidity of onset of encephalopathy does not seem to influence survival. Viral hepatitis is the cause in approximately 95-100% of patients, who therefore constitute a more homogeneous population than AHF patients in the West. In India, hepatitis E (HEV) and hepatitis B (HBV) viruses are the most important causes of AHF; approximately 60% of cases are caused by to these viruses. Hepatitis B virus core mutants are very important agents in cases where hepatitis B results in AHF in this country. Half of the patients with AHF admitted to our centre are female, one-quarter of whom are pregnant. Therefore, pregnant females who contract viral hepatitis constitute a high-risk group for the development of AHF. However, the outcome of AHF in this group is similar to that in non-pregnant women and men. No association with any particular virus has been identified among sporadic cases of AHF. In our centre, approximately one-third of AHF patients survive with aggressive conservative therapy, whereas two-thirds of deaths occur within 72 h of hospitalization. Cerebral oedema and sepsis are the major fatal complications. Both fungal and gram-negative bacteria are major causes of sepsis. Among patients with AHF, despite the presence of sepsis, its overt clinical features (i.e. fever, leucocytosis) may be absent and objective documentation of the presence of sepsis in such patients is achieved by repeated culture of various body fluids. It should be possible to develop simple, clinical prognostic markers for AHF in this geographical region, in order to identify patients suitable for liver transplantation.

Adult↗
PubMed2000

Pulmonary homograft: should it be used in the aortic position?

OBJECTIVE: Retrospective analysis was performed to determine the suitability of pulmonary homograft as an aortic valve substitute. METHODS: From January 1994 through June 1999, 147 patients (mean age, 32.2 +/- 17.3 years) underwent aortic valve replacement with either an aortic homograft (group 1: n = 103, 25 fresh antibiotic preserved and 78 cryopreserved) or a pulmonary homograft (group 2: n = 44, 11 antibiotic preserved and 33 cryopreserved). In group 1 a scalloped subcoronary technique was used in 64 patients, and a root replacement technique was used in 39 patients. In group 2 the scalloped subcoronary technique was used in 34 patients, and the root replacement technique was used in 10 patients. RESULTS: There were 131 operative survivors (group 1 = 91; group 2 = 40). Follow-up ranged from 2 to 62 months. In group 1 none of the patients had significant aortic regurgitation during the hospital stay. Three patients (all having undergone the scalloped subcoronary technique) had moderate aortic regurgitation after 6 to 32 months. In group 2, 10 patients (9 having undergone the scalloped subcoronary technique and 1 having undergone the root replacement technique) developed significant regurgitation: 2 intraoperatively, 5 in the early postoperative period before discharge from the hospital, and 3 during late follow-up 6 to 12 months postoperatively. Among the various risk factors analyzed for overall homograft failure, use of a pulmonary homograft was the single independent predictor of valve failure (odds ratio, 8.6; 95% confidence interval, 1.9-39; P =.006). CONCLUSION: Pulmonary homograft, when inserted by means of a scalloped subcoronary technique, is not a suitable aortic valve substitute.

Adolescent↗
PubMed2000

Homograft mitral valve replacement: five years' results.

OBJECTIVE: Results of mitral valve replacement with a mitral homograft were evaluated at 5 years to assess the suitability of the procedure. METHODS: Thirty-seven patients (25 male subjects) aged 10 to 49 years (mean, 32 +/- 10 years) with rheumatic mitral valve disease underwent total (n = 35) or partial (n = 2) mitral valve replacement with a fresh antibiotic-preserved (n = 23) or cryopreserved (n = 14) mitral homograft. The predominant lesion was mitral stenosis (n = 30). RESULTS: There were 5 early deaths. Operative survivors were followed up for 1 to 60 months (mean, 26.6 +/- 12 months). Among these, 21 patients had severe mitral regurgitation during the follow-up period; 3 died and 8 underwent reoperation. The homograft failure rate was not affected by preoperative physiologic lesion (stenosis vs regurgitation, P =.4), type of homograft (antibiotic-preserved vs cryopreserved homograft, P =.9), papillary muscle pretreatment (yes vs no, P =.9), or addition of posterior collar annuloplasty (yes vs no, P =.2). Among the remaining patients, 5 had moderate mitral regurgitation, 4 had either trivial or mild mitral regurgitation, and 2 were lost to follow-up. Study of the explanted mitral homografts (n = 8) revealed that disruption of one of the donor papillary muscles was responsible for early failures (n = 2), whereas cuspal and chordal degeneration was responsible for late failures (n = 6). Microscopically, the explanted valve lacked any viable cellular elements, and there was no evidence of immunologic injury to the homografts. CONCLUSION: The mitral homograft did not fulfill our expectations as a suitable substitute for the diseased mitral valve.

Adolescent↗
PubMed2000

Effect of photodynamic therapy on recurrent pituitary adenomas: clinical phase I/II trial--an early report.

Pituitary adenomas, although histologically benign, are not always curable by surgery alone, principally because of dural infiltration, as well as their peculiar anatomical location. Radiotherapy has been employed as an adjuvant therapy to address residual disease with favourable results. This approach is, however, not without side effects, and it cannot be repeated. We are therefore investigating the effectiveness of photodynamic therapy (PDT) on recurrent pituitary adenomas in humans. This study details the protocol applied to 12 patients with recurrent pituitary adenomas, which involved systemic administration of photosensitizer (Photofrin) followed, after a period of 24-48 h, by intraoperative illumination of the tumour bed using 630 nm laser light. The primary end points were visual, endocrine and radiological improvement. The incidence of side effects was also monitored. The longest follow-up is 2 years. Most patients suffering from visual acuity or field defects have shown improvement when followed for 12 months or more. Three patients showed complete recovery of their visual fields. All those who presented with functional adenomas have shown reduction in their hormone levels. Tumour volume, relative to the preoperative size, was 122, 87, 66, 60 and 46% at 4 days, and 3, 6, 18 and 24 months, respectively. One patient developed severe skin photosensitization due to early exposure to direct sunlight and three others displayed minor skin reactions. There was no treatment-related mortality or morbidity. One patient (operated transcranially) developed hemiparesis postoperatively, which recovered completely. We think this is unrelated to the treatment. This prospective study demonstrates that PDT may be safely applied to the pituitary fossa by the trans-sphenoidal route and indicates the need for a randomized, controlled trial in order to establish its therapeutic potential.

Adenoma↗
PubMed2000

Control of photon beam dose profiles by localized transverse magnetic fields.

Unlike electron beams, scant attention has been paid in the literature to possible magnetic field effects on therapeutic photon beams. Generally, dose profiles are considered to be fully determined by beam shape, photon spectrum and the substances in the beam path. Here we show that small superconducting magnets can exercise potentially useful control over photon dose profiles. The magnet produces a locally strong transverse field with large gradients and is applied to the tissue surface below which the photon beam is passing. For one practical magnet design, our simulations, which use the EGS-4 Monte Carlo code modified to include magnetic field effects, show significant intensification and shielding effects. In water phantoms, the effects extend to 3-4 cm or more beyond the warm face of the cryostat and greater distances are achieved in phantoms simulating lung (density approximately 0.3). Advances in applying the concept and in superconducting materials and magnet design hold promise for extending these ranges.

Humans↗
PubMed2000

Phase separation and shape deformation of two-phase membranes

Within a coupled-field Ginzburg-Landau model we study analytically phase separation and accompanying shape deformation on a two-phase elastic membrane in simple geometries such as cylinders, spheres, and tori. Using an exact periodic domain wall solution we solve for the shape and phase separating field, and estimate the degree of deformation of the membrane. The results are pertinent to preferential phase separation in regions of differing curvature on a variety of vesicles.

Journal Article↗