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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 1,711 records · Page 95Linked to original sources

Value of digital image processing of two-dimensional echocardiograms in differentiating active from chronic vegetations of infective endocarditis.

The ability of a computer-based image digitizing system to differentiate "active" from "chronic" valvular vegetations was evaluated. Twenty-two patients with newly diagnosed infective endocarditis were studied prospectively by serial two-dimensional echocardiograms. Two comparable images (active and chronic) from the same patient taken several weeks apart (range, 4-17 weeks) after initiation of therapy were obtained at end diastole with identical gain settings. The images were digitized, magnified, and displayed on a high-resolution color monitor. The mean pixel intensity of the valvular vegetation in the active stage was 20.6 +/- 3.6 (mean +/- SD), which increased to 34.4 +/- 4.3 in the chronic stage (p less than 0.01). Because there was some overlap of values, an additional standardization procedure was used in the last eight patients. In these eight patients, the mean pixel intensity of the vegetations in the active stage was 17.5 +/- 1.1, and it increased at 4 weeks to 25.0 +/- 1.2 (p less than 0.05) and further increased in the chronic stage to 33.6 +/- 3.1 (p less than 0.05). There was no overlap of values between the active and chronic stages. Three clinical states are of particular interest: 1) The mean pixel intensity of the vegetations remained unchanged (23 vs. 24) in one patient who did not respond to antibiotic therapy. 2) The mean pixel intensity of the vegetations fell from 35 to 24 when one patient developed reinfection of the same valve, and with treatment, mean pixel intensity once again increased to 34. 3) The mean pixel intensity of the vegetations in five patients with culture negative infective endocarditis was low (21.6 +/- 1.9) and increased (33.6 +/- 6.0, p less than 0.05) during the chronic stage. The mean vegetation size was 0.73 +/- 0.30 cm2 in the active stage and decreased to 0.56 +/- 0.24 cm2 (p less than 0.05) in the chronic stage; however, in six of 22 patients (27%), vegetation size did not decrease with clinical cure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Intracranial and intratemporal meningiomas with primary otologic symptoms.

Intratemporal extensions of cerebellopontine angle (CPA) meningiomas are unusual and primary intratympanic meningiomas are extremely rare. The initial symptoms of both types are otologic. The presenting symptoms of even large meningiomas of the cerebellopontine angle can also be otologic. In this article we report the clinical features, diagnosis, and management of five CPA meningiomas, three combined intratemporal and CPA meningiomas, and one primary intratympanic meningioma.

Adolescent↗

Direct sagittal CT in the evaluation of temporal bone disease.

The human temporal bone is an extremely complex structure. Direct axial and coronal CT sections are quite satisfactory for imaging the anatomy of the temporal bone; however, many relationships of the normal and pathologic anatomic detail of the temporal bone are better seen with direct sagittal CT sections. The sagittal projection is of interest to surgeons, as it has the advantage of following the plane of surgical approach. This article describes the advantages of using direct sagittal sections for studying various diseases of the temporal bone. The CT sections were obtained with the aid of a new head holder added to our GE CT 9800 scanner. The direct sagittal projection was found to be extremely useful for evaluating diseases involving the vertical segment of the facial nerve canal, vestibular aqueduct, tegmen tympani, sigmoid sinus plate, sinodural angle, carotid canal, jugular fossa, external auditory canal, middle ear cavity, infra- and supralabyrinthine air cells, and temporomandibular joint.

Adolescent↗

"Immunoregulatory effects of cimetidine: inhibition of suppressor cell effector function in vivo".

The effects of cimetidine upon suppressor cell effector function in a well-studied murine model of contact hypersensitivity were examined. Intravenous inoculation of BALB/c mice with DNP-coupled syngeneic spleen cells induced the production of DNP-specific suppressor cells which was demonstrated by a reduction in ear swelling after contact sensitization with 1-fluoro-2, 4-dinitrobenzene (DNFB) following transfer of spleen and lymph node cells to naive syngeneic recipients. Cimetidine treatment of mice who had also received suppressor cells eliminated the manifestation of suppressor cell activity as measured by the development of normal immunologic response following contact sensitization with DNFB. While all the groups receiving cimetidine showed restoration of delayed hypersensitivity, the maximum effect was seen when 50 mg/kg of cimetidine was administered on Day 5 (day of challenge). These results indicate that, in addition to its previously described inhibitory role in suppressor cell induction, cimetidine is also capable of inhibiting suppressor cell effector function. The involvement of histamine in both these processes in vivo is also suggested.

Animals↗

Tumors and tumor-like conditions of the middle ear and mastoid: role of CT and MRI. An analysis of 100 cases.

CT and MRI scanning provide valuable information in determining location and extension of middle ear and mastoid tumors and tumor-like conditions. The bone anatomy depicted by CT better delineates the involvement of the middle ear diseases. In glomus tumors, facial nerve tumors, and other cases including temporal bone metastases, the combination of CT and MR imaging is exceedingly useful in the diagnosis and management of patients.

Cranial Nerve Neoplasms↗

Diagnostic value of cardinal signs/symptoms in paucibacillary leprosy.

With the help of sensitivity and specificity criteria, an attempt is made to quantify the gain in certainty in diagnosis with the use of various cardinal signs/symptoms (S/s) of leprosy in order to study their predictive value in correct diagnosis of paucibacillary leprosy (PB) by the Paramedical Workers. The study was based on the findings in 326 new cases of paucibacillary leprosy detected by 10 paramedical workers during a recent field survey. Observations in the present study confirm the scientific basis of presently used combinations of cardinal S/s for correct diagnosis of leprosy especially the combination of (skin) patch with loss/impairment of sensation. The detailed observations made in the study are discussed in this communication.

Adult↗

A double-blind controlled clinical trial to assess the role of anti-histamines in the treatment of multi-bacillary leprosy.

A double blind controlled clinical trial to assess the role of anti-histamines as a supplement in the treatment of leprosy was conducted in multi-bacillary cases of leprosy. In all, 120 patients with lepromatous or borderline leprosy were randomly allocated to a regimen of clofazimine and dapsone for 12 months with or without a supplement of pheniramine maleate for the first 3 months. During the 12-month period, 92% of the patients who received the supplement and 86% of the patients who had not received it had moderate or marked clinical improvement. The BI values decreased from 4.1 to 3.4 and 4.2 to 3.3, respectively. The results over the 12-month period showed that the addition of the antihistamine had not enhanced the efficacy of the regimen as evidenced by clinical and bacteriological findings.

Adolescent↗

Relative cross reactivity of habanin, lepromin and tuberculin in guinea pigs sensitized with homologous and heterologous mycobacteria.

An atypical strain Mycobacterium habana has been studied for its antigenic cross reactivity with delayed type of hypersensitivity responses in guinea pigs. Guinea pigs sensitized with M. habana, M. leprae and M. tuberculosis when challenged with habanin, lepromin and tuberculin in criss-cross fashion have demonstrated strong cross reactivity with each other. Possibilities of developing M. habana as a vaccine against tuberculosis and/or leprosy has been discussed.

Animals↗