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Biomedical subjects

A Sethi

Publications and source records attributed to A Sethi.

At least 19 recordsLinked to original sources

Incorporation of diaphyseal sequestra in chronic haematogenous osteomyelitis.

Seventeen patients with haematogenous osteomyelitis and long diaphyseal sequestra are reported. Treatment was incision and drainage with antibiotics for at least 6 to 8 weeks, the limb being protected in plaster for a long time. The sequestra became incorporated in every case. Sequestrectomy should only be undertaken when successive radiographs show no reduction in size of the sequestrum and an increase in the amount of the involucrum.

Adolescent

Surgical treatment of complete acromioclavicular dislocation using the coracoacromial ligament and coracoclavicular fixation: report of a technique in 14 patients.

Fourteen cases of a complete dislocation of the acromioclavicular joint were treated using a modified technique of surgical repair involving the transfer of the coracoacromial ligament to reconstruct the coracoclavicular ligaments and coracoclavicular fixation with a screw. In addition, the lateral 2 cm of the clavicle was removed and the coracoacromial ligament attached to the raw surface. Eleven patients underwent surgery < 2 weeks after injury, whereas three underwent surgery 6 months after the initial episode. Follow-up of 2-4 years showed excellent results in 12 and good in two cases. It is our recommendation that coracoclavicular ligament reconstruction should be supplemented with clavicular fixation to the coracoid to ensure acromioclavicular alignment.

Acromioclavicular Joint

Restoration of the maxillary arch using implants, natural teeth and the Konus crown: a case study.

Restoring the maxillary arch by using a suprastructure retained by a Konus crown means that the patient can remove the crown for oral hygiene. This construction enables large embrasure spaces to be avoided without compromising phonetics, that is, without adversely affecting the patient's speech. It also enables the dental surgeon to monitor the tooth and implant abutments and the soft tissues around them. In this article we demonstrate successful restoration of the maxillary arch by the use of Konus crowns on a combination of implants and natural teeth.

Crowns

Brain stem auditory evoked responses during the cold pressor test.

This study was conducted to determine changes, if any, in Brain stem auditory evoked responses (BAEP's) during the cold pressor test (CPT) in healthy human subjects. Thirteen subjects (age 18-25 yrs) were selected for the study. Their BAEP's were recorded using standardized technique employing 10-20 international electrode placement system and sound click stimuli of specified intensity, duration and frequency. The standard CPT was performed in the non-dominant hand and the BAEP's, heart rate and blood pressure were recorded before and during the CPT. The values of absolute peak latencies and amplitude of evoked responses were statistically analysed. The amplitude of wave V showed a significant increase (P < 0.05) during the CPT (0.47 +/- 0.203 and 0.37 +/- 0.174 mu v before and during CPT respectively). This could be due to interaction of activated central ascending monoaminergic pathways or nociceptive afferents with the midbrain auditory generator so as to increase it's activity.

Acoustic Stimulation

Sensory nerve conduction during cold pressor response in humans.

A study was carried out to find the correlation, if any of autonomic responses and experimental pain induced during the cold pressor test (CPT) with the median nerve sensory conduction velocity (SCV). In 19 healthy subjects who volunteered for the study, the nondominant hand of each was subjected to the CPT and, pain parameters, heart rate, blood pressure and SCV were recorded. Dominant median nerve SCV was measured by orthodromic stimulation of the index finger and evoked responses were recorded at the wrist. In each subject, 32 evoked action potential responses were averaged to determine the SCV. Median nerve SCV of 57.8 +/- 5.2, 56.6 +/- 5.1, 57.0 +/- 5.2 and 57.8 +/- 5.1 m/sec were recorded before, during, immediately after and after ten minutes of the CPT, respectively. The SCV and the amplitude of the evoked response were significantly (P < 0.001 and P < 0.01 respectively) decreased during the CPT. A significant relationship (P < 0.05) was found between nerve conduction parameters and diastolic blood pressure recorded before the CPT. These findings suggest that sympathetic overactivity and/or cold induced pain interacts with sensory conduction in the contralateral median nerve so as to decrease its conduction velocity. There also exists a relationship between SCV and vasomotor mechanisms controlling peripheral resistance, and hence the diastolic pressure.

Adolescent

Allograft in the treatment of benign cystic lesions of bone.

Seventeen patients with benign cystic osseous lesions were treated by curettage and grafting using allogenic decalcified bone. Human bones were partially decalcified using 0.6 N HCl and preserved in 90% ethanol in a deep freezer at -16 degrees C. The cystic lesions were: 5 cases of fibrous dysplasia, 4 aneurysmal bone cysts, 3 simple bone cysts, 2 giant-cell tumours, 1 chondromyxoid fibroma, 1 non-ossifying fibroma and 1 fibrous cortical defect. The bones involved were: femur, tibia, humerus, fibula and calcaneum. Infection was a complication in three patients. In two of these it did not interfere with healing, but in one it persisted for more than 1 year with partial resorption of the graft. The time to adequate incorporation of the graft varied from 6 to 9 months in children and 9 to 15 months in adults. The overall response compares favourably with that to allograft from more sophisticated bone banks.

Adolescent

Precise site location for implants using CT scans: a technical note.

Information gained by preoperative imaging techniques must be accurately related to the surgical site. The inability to do this severely diminishes the benefit of the diagnostic imaging. The CT scan is capable of providing considerable information regarding the jaws. The use of radiopaque markers to identify preselected points on the image is readily done by placing markers in the wax registration rims that are worn during the scan. The position of these markers is transferred to the mouth with a surgical template, facilitating surgery and reducing the incidence of anatomic accidents caused by lack of orientation.

Dental Implantation, Endosseous

Childhood neurocysticercosis--epidemiology, diagnosis and course.

Neurocysticercosis was diagnosed in 0.89% of children enrolled in our Child Neurology Clinic in the years 1979 to 1990. The commonest presenting symptom was seizures (90%) followed by raised intracranial pressure (44%). CT scans revealed a variety of lesions including low and high attenuation cysts, periventricular edema, hydrocephalus and calcification. ELISA was useful in substantiating the diagnosis in almost 70% of cases. Only 18 patients who had active disease merited treatment with praziquantel. The clinical and CT response was good. Follow-up revealed spontaneous quiescence in many patients with inactive disease.

Adolescent

Hydrolytic enzymes in leprosy sera.

Serum samples collected from 45 untreated leprosy patients and 10 healthy subjects were studied for the activities of alkaline phosphatase, N-acetyl beta-glucosaminidase and beta-glucuronidase. A highly significant increase in the specific activity of these enzymes was observed in all types of leprosy patients as compared to controls. Increase in the level of circulatory hydrolytic enzymes could be a tissue damaging factor and may be responsible for many of the lesions seen in leprosy.

Acetylglucosaminidase

The role of a critical care unit in an epidemic.

The role of a critical care unit in life-threatening situations is well established. The management of 52 children with acute gastroenteritis and 22 children with acute paralytic poliomyelitis as part of recent epidemics is described. The solutions to the problems in the critical care management of these 74 victims (out of a total of 6197 patients admitted during the epidemics) are discussed.

Acute Disease

Oxidative metabolic response of peripheral blood monocytes of monkeys during primary and chronic Plasmodium knowlesi infection.

The oxygen free radical generation (as determined by cytochrome c reduction) and respiratory burst enzyme activities were measured in the peripheral blood monocytes before infecting normal animals, during primary Plasmodium knowlesi infection, after treatment of primary infection with chloroquine, after administration of various subcurative doses following reinfection and after establishment of chronicity. For all the parameters of the oxidative response, no significant difference was observed during primary infection and after curing of primary infection. However, the response was significantly increased in the reinfected monkeys given subcurative therapy; this was followed by a sharp decline after the 4th subcurative dose, after which the response continued to be low until the attainment of chronicity. The results of the present study exclude the possibility of the increase in oxidative metabolism being the effect of the drug (i.e. chloroquine), since no significant difference was observed during primary infection and after its cure. The sustained low grade parasitaemia in the chronic stage, in spite of the sharp decrease in the oxidative response, suggests that some nonoxidant parasitic killing mechanism might be playing a role in the regulation of parasitaemia.

Animals

Stimulation of the human immunodeficiency virus type 2 (HIV-2) gene expression by the cytomegalovirus and HIV-2 transactivator gene.

Human immunodeficiency virus (HIV) often causes latent infection. Transactivation by some DNA viruses has been implicated in inducing HIV-1 replication and pathogenesis. The transactivator (IE-2) gene of the human cytomegalovirus (CMV) can enhance HIV-2 as well as HIV-1 gene expression in vitro. This inducer can act in concert with the HIV-2 tat gene and T-cell activation in enhancing gene expression in human CD4+ lymphocytes. While the HIV-2 and HIV-1 tat genes and T-cell activators apparently employ independent modes of action, the CMV transactivator in combination with the HIV-2 tat or T-cell activators may employ a gene activation pathway with some common and some distinct components. Both HIV-2 and CMV transactivators enhance HIV-2 gene expression by transcriptional activation involving transcript initiation as well as elongation, with CMV transactivator affecting elongation more than the initiation. A significant proportion of transcripts appear to terminate prematurely in the absence of transactivators. Deletion mutation analysis of the HIV-2 long terminal repeat (LTR) suggests that the element that responds to CMV transactivation in human CD4+ lymphocytes is either a diffuse one or located downstream of the HIV-2 enhancer element.

CD4-Positive T-Lymphocytes

Thymosin alpha 1 enhancement of human lymphocyte proliferation is not mediated by prostaglandin E2.

Prostaglandins of the E series have been implicated as possible mediators of thymosin alpha 1 (TA-1) effect on mitogen stimulated lymphoproliferation. In the present study human peripheral blood mononuclear cells were stimulated with concanavalin A in the presence of TA-1, prostaglandin E2 and indomethacin individually, or in combination. Both TA-1 and indomethacin significantly enhanced the proliferative response over that seen with mitogen alone (less than 0.001). The magnitude of enhancement observed with indomethacin (20 microM) was considerably less than that of TA-1 and it was abolished with prostaglandin E2. The combination of indomethacin and TA-1 did not alter TA-1 effect and prostaglandin E2 (up to 250 ng/ml) did not abolish thymosin effect. These results suggest that TA-1 and prostaglandin E2 have opposite effects and that thymosin enhancement of mitogen induced proliferation is not mediated by prostaglandin E2.

Concanavalin A