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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 1,243 records · Page 69Linked to original sources
PubMed1993

Detection of antisense transcripts in transgenic plants by RT-PCR.

A reverse transcriptase-polymerase chain reaction (RT-PCR) where one oligonucleotide primer is end-labelled has been used to analyse expression in transgenic plants carrying antisense gene constructs. Specific detection of both sense and antisense RNA transcripts of the spliceosomal protein gene, U2B'', was achieved using the same pair of oligonucleotide primers. To maintain specificity, a reaction step in which reverse transcriptase was inactivated and RNA digested was found to be essential.

Base Sequence↗
PubMed1993

Development of embryos from natural cycle in-vitro fertilization: impact of medium type and female infertility factors.

Single embryos derived from natural cycle in-vitro fertilization (IVF) were graded during the pre-transfer culture period using morphological criteria. Most embryos developed well in culture with 96% showing continuing division and 68% showing good morphological appearance, although embryo quality tended to decline with an increased incidence of fragmentation and uneven cleavage as division proceeded. Both the pregnancy rate and the distribution of embryo grades were similar among four different culture media used, suggesting that choice of medium had little impact on outcome. In contrast, there were marked differences in pregnancy rate according to the type of infertility, which was not reflected in a decrease in embryo quality. However, although embryos from patients with tubal infertility implanted and formed viable pregnancies irrespective of morphological appearance, only 'good' quality embryos from patients with non-tubal (or 'unexplained') infertility were able to implant. Thus the appearance of the embryo derived from natural cycle IVF in women with unexplained infertility may be of clinical relevance.

Adult↗
PubMed1993

Perinatal mortality in rural India with special reference to high risk pregnancies.

One-thousand-and-sixty-five pregnant mothers among a rural population of 30,000 in Uttar Pradesh were followed for 1 year. A still birth rate of 26.1 and perinatal mortality rate of 121.1 per thousand births were registered. Early neonatal mortality rate was found to be 97.4 per thousand live births. Twenty per cent of the women were identified with high risk factors. Inadequate or no antenatal care, bad obstetric history, and prolonged labour attributed to 13, 20, and 27 per cent of the risk, respectively, with a respective relative risk of 2.23, 3.1, and 4.09 times. These three factors were found to be the major and significant contributors to high perinatal mortality amongst the 'high risk' group. Selective extension of comprehensive M.C.H. Care to this group using the high risk approach is expected to lower perinatal mortality in rural community where M.C.H. services are far from optimum.

Female↗
PubMed1993

Evidence for involvement of nitric oxide in pretectal analgesia in rat.

The study was undertaken to evaluate the role of nitric oxide (NO) in pretectal (PTN)-induced analgesia in rats. Microinjection of varying concentrations of L-arginine (1 nM to 1 microM) produced a quick, long-lasting and concentration-dependent analgesic response, whereas similar concentrations of D-arginine failed to produce analgesia. Moreover pretreatment with N-nitro-L-arginine methyl ester (L-NAME, 1 microM) significantly prevented L-arginine induced analgesia. Further, pretreatment of animals with methylene blue, a known guanylate cyclase inhibitor also prevented the development of analgesia. Our study suggests that L-arginine caused production of NO, which in turn activates pretectal analgesic system involving cyclic GMP.

Analgesia↗
PubMed1993

Analgesic effect of morphine, clonidine and serotonin microinjected into the PTN of rats.

The study was aimed to delineate the neurotransmitter receptors involved in pretectal analgesic mechanisms by direct microinjection of neurotransmitter agonists and antagonists through chronically implanted cannulae in the pretectal nucleus of rats. Morphine, clonidine and serotonin, at doses of 2.5 and 5.0 micrograms microinjected into the pretectal nucleus, produced a significant and prolonged analgesia as measured by the tail-flick test. The analgesia produced by morphine, clonidine and serotonin is significantly attenuated by pretreatment of the animals with naloxone (1 micrograms), yohimbine (5 micrograms) and methysergide (5-10 micrograms) respectively. The results indicate the possible involvement of opioid, adrenergic and serotonergic mechanisms in pretectal analgesia.

Analgesics↗
PubMed1993

Diagnosis of diabetic gastroparesis on Tc-99m hepatobiliary scintigraphy.

Diabetic gastroparesis is a common problem in diabetics, especially insulin-dependent diabetics. The diagnosis usually is suggested on plain radiographs and confirmed on either upper gastrointestinal barium series or radionuclide gastric emptying studies. The clinical diagnosis is not always easy and some patients may present atypically with right upper quadrant pain simulating acute cholecystitis. In these patients, hepatobiliary scintigraphy may be the initial investigation performed and may first demonstrate unsuspected gastroparesis. Therefore, it is useful for the nuclear medicine physician to be aware of this entity to ensure early diagnosis and prompt treatment. The authors report one such case of diabetic gastroparesis that was diagnosed initially on a Tc-99m hepatobiliary scan.

Adult↗
PubMed1993

Interspace distraction and graft subsidence after anterior lumbar fusion with femoral strut allograft.

The authors performed a retrospective review of 32 patients who had undergone a single-level anterior lumbar fusion with femoral strut allograft as an isolated procedure. The goal of the study was to use clinical radiographs to measure interspace distraction, graft subsidence, interspace collapse, the nature of allograft incorporation, and to correlate these results with successful arthrodesis. Results were categorized according to plain radiographic appearance and flexion/extension stability. Sixty-six percent of the group exhibited radiographic union with flexion/extension stability. Twenty-two percent exhibited stability on the flexion-extension analysis but less than complete arthrodesis was present. Twelve percent exhibited radiographic non-union and flexion-extension instability. Interspace distraction of 11 mm was obtained initially with a follow-up distraction of 5.5 mm. Graft subsidence was noted posteriorly in 27 patients with an average subsidence of 4 mm. The authors' conclusions were: 1) Interspace distraction can be achieved with anterior lumbar fusion if appropriate interbody grafts are used. 2) Despite a solid arthrodesis rate of only 66%, "functional arthrodesis" was achieved in 88%. In a retrospective review of patients who underwent anterior lumbar fusion with femoral strut allograft, interspace distraction, graft subsidence, and incorporation and arthrodesis status were measured. A solid arthrodesis was achieved in 66% of the patients, and functional arthrodesis in another 22%. Interspace distraction was maintained in 59% of cases.

Adult↗
PubMed1993

Preoxygenation techniques: the value of nitrous oxide.

Changes in arterial oxygen saturation during induction of anaesthesia and intubation were studied using the pulse oximeter. Seventy-five young ASA I patients undergoing elective uncomplicated surgery were divided equally into three groups. The patients were preoxygenated with 100% oxygen, 50% oxygen: 50% nitrous oxide or 30% oxygen: 70% nitrous oxide for 1 min. All were then induced with thiopentone, paralysed with suxamethonium and orally intubated. Arterial oxygen saturations were continuously recorded by a separate investigator. All groups showed similar arterial desaturation during suxamethonium-induced apnoea and intubation, but the degree of desaturation was not clinically significant and no patient showed clinical signs of hypoxaemia. Preoxygenation with mixtures of oxygen and nitrous oxide can hasten the build-up of alveolar nitrous oxide concentration and help to smooth induction without compromising oxygenation of patients.

Adolescent↗
PubMed1993

Bullous pemphigoid in an Aborigine.

OBJECTIVE: To present the first case of bullous pemphigoid in an Australian Aborigine. CLINICAL FEATURES: A 47 year old female aborigine presented with a three week history of a generalised skin eruption consistent with bullous pemphigoid. Immunohistological examination confirmed the diagnosis. Therapy required high dose oral steroids, azathioprine and erythromycin as well as topical agents. Treatment was complicated by isolation and poor compliance but was ultimately successful in inducing and retaining remission. CONCLUSION: This is the first description of bullous pemphigoid in an Australian Aborigine. We recommend early biopsy to confirm diagnosis and plan therapy, and careful attention to patient education to encourage compliance.

Australia↗
PubMed1993

Cerebral infarction following thoracic herpes zoster.

OBJECTIVE: To present a case of cerebral infarction following thoracic herpes zoster presenting as Gerstmann's syndrome. CLINICAL FEATURES: A 61 year old male developed herpes zoster of T 1-2 dermatomes. Four months later he developed a confusional state together with expressive aphasia, dyscalculia, dysgraphia and finger agnosia with no long tract signs. CT scan of head showed recent infarction of this left parietal lobe. He received a five day course of acyclovir 800 mg four times daily and showed slow but steady improvement. CONCLUSION: Herpes zoster is uncommonly followed by cerebral infarction. Acyclovir may have a role in therapy of this complication.

Acyclovir↗
PubMed1993

Functional outcome of branch retinal vein occlusion after photocoagulation with various laser wavelengths--an automated perimetric analysis.

This study highlights the comparative efficacy of three different laser wavelengths--argon green, argon blue-green, and krypton red--for sector photocoagulation in fresh cases of branch retinal vein occlusion. The mean Logarithm of minimal angle of resolution (LogMAR) improved in the argon green and argon blue-green groups but decreased in the krypton red group. Statistical analysis of the automated visual fields in these eyes showed a mean change in corrected pattern standard deviation value, with increase in all three groups--minimal increase in the argon blue-green group and maximal in the krypton red group, suggesting maximum visual field defect in the krypton laser group. To conclude, the green and the blue-green wavelengths gave results that were decidedly superior to those given by krypton red: further, argon blue-green had an edge over the green wavelength.

Fluorescein Angiography↗
PubMed1993

Efficacy of cefuroxime axetil suspension compared with that of penicillin V suspension in children with group A streptococcal pharyngitis.

The bacteriological and clinical efficacies of cefuroxime axetil suspension (20 mg/kg of body weight per day in two divided doses) were compared with those of penicillin V suspension (50 mg/kg/day in three divided doses) in a multicenter, randomized, evaluator-blinded study. Children aged 2 to 13 years with clinical signs and symptoms of acute pharyngitis and a positive throat culture for group A beta-hemolytic streptococci (GABHS) were eligible. Patients were assessed and samples from the throat for culture were obtained at the time of diagnosis, 3 to 7 days after the initiation of treatment, and 4 to 8 days and 19 to 25 days after the completion of 10 days of therapy. Of the 385 evaluable patients, GABHS were eradicated from 244 of 259 (94.2%) cefuroxime-treated patients and 106 of 126 (84.1%) penicillin-treated patients (P = 0.001). Complete resolution of the signs and symptoms present at the time of diagnosis was achieved in 238 of 259 (91.9%) cefuroxime-treated patients and 102 of 126 (81.0%) penicillin-treated patients (P = 0.001). Potential drug-related adverse events were reported in 7.0 and 3.2% of the cefuroxime- and penicillin-treated patients, respectively (P = 0.078). In the present study, cefuroxime axetil suspension given twice daily resulted in significantly greater bacteriological and clinical efficacies than those of penicillin V suspension given three times daily to pediatric patients with acute pharyngitis and a positive throat culture for GABHS.

Acute Disease↗
PubMed1993

Long term results of endoscopic dilatation for corrosive oesophageal strictures.

Although dilatation is the treatment of choice for most patients with benign oesophageal strictures, there is little information on its efficacy and safety in corrosive oesophageal strictures. Of 123 adults with benign oesophageal strictures treated by endoscopic dilatation, 52 (42.3%) had strictures after corrosive ingestion and 39 (31.7%) had peptic strictures. Treatment was considered adequate if the oesophageal lumen could be dilated to 15 mm and there was complete relief of dysphagia. If dysphagia recurred after adequate initial dilatation, the stricture was dilated again up to 15 mm. Initial dilatation was adequate in 93.6% of patients with corrosive strictures and this success rate was comparable with that of the peptic stricture group (100%, p > 0.05). Long term success after adequate initial dilatation was studied in 36 patients with corrosive strictures (mean follow up 32.36 (17.12) months, range 6-60) and 33 patients with peptic strictures (mean follow up 36.32 (17.9) months, range 6-60). The mean (SEM) number of symptomatic recurrences per patient month during the total follow up period in the corrosive group was significantly higher than that in the peptic group (0.27 (0.04) v 0.07 (0.02), p < 0.001). The recurrence rate in the corrosive group, however, decreased over time, and after 12 months it was significantly (p < 0.001) lower than the recurrence rate in the first six months. After 36 months, the difference in the recurrence rate in the two groups was not significant (p > 0.05). Only nine oesophageal perforations occurred during a total of 1373 dilatation treatments (procedure related incidence 0.66%), and eight of these were in the corrosive stricture group. These patients were managed conservatively and subsequently strictures were dilated adequately in all. Endoscopic dilatation is safe and effective for short and long term relief of dysphagia in patients with corrosive oesophageal strictures.

Adult↗