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Biomedical subjects

Y N Mehra

Publications and source records attributed to Y N Mehra.

At least 19 recordsLinked to original sources
PubMed2001

Incidence of pharyngeal hypophysis in neonates a histologic study.

The presence of adenohypophysial tissue in the nasopharynx is no longer disputed. This study was performed in 50 neonatal cadavers subjected to medical autopsy within 6 hours of death. The aim was to study the incidence of extrasellar pituitary tissue in the nasopharynx and its various histologic cell types. The transpalatal approach was used to obtain the specimens. The specimens were stained with hematoxylin and eosin and periodic acid-Schiff-orange G for selective demonstration of adenohypophysial cells. Histopathologic evaluation led to the detection of pituitary tissue in 16% of the examined specimens. Selective staining demonstrated a 6% positive incidence of adenohypophysial cells. The pharyngeal hypophysis exists in 2 forms: a typical adenohypophysial collection of cells and an atypical subepithelial cluster. The incidence of hypophysial tissue was higher in the older neonates, perhaps because of hormonal stimulation of the caudal remnant of Rathke's pouch.

Adenoids↗
PubMed1996

Rhabdomyosarcoma of head and neck--an analysis of 24 cases.

Clinical records of 24 cases or rhabdomyosarcoma involving head and neck region were studied. Majority of the patients (83.3%) were under five years of age. The common sites of involvement were the middle ear (50%) and the nasopharynx (17%). Embryonal variety was noted in majority of patients (83.3%). Pain and swelling in the post aural or pre-auricular region was the commonest mode of presentation. Last four cranial nerves were involved in eight patients and four patients had extension of the tumor in the posterior cranial fossa. Twenty patients having embryonal rhabdomyosarcoma received combination of chemotherapy and radiotherapy. Half of these remained tumor free upto six months. Surgical extirpation was done only in two patients, where the disease was localised. The tumor in these two patients was of pleomorphic variety and did not recur till two years after surgery.

Adolescent↗
PubMed1994

A study of P300 in melancholic depression--correlation with psychotic features.

The relationship between delusions and hallucinations (psychotic features) in melancholic depression and auditory P300 was studied. Forty patients with melancholic depression as per DSM-III-R were studied, 20 of whom had hallucinations and/or delusions. The 20 patients of the two groups were individually matched on age, gender, sociodemographic variables, and psychopathology (except for psychotic features). Auditory P300 obtained by the "oddball paradigm" showed that those with hallucinations and/or delusions had a significantly smaller P3 amplitude. Significant correlations between "psychotic features" and P3 amplitude was found. Implications of these findings on research, classification, and management of depression have been outlined.

Acoustic Stimulation↗
PubMed1991

Post traumatic facial paralysis--a review.

A retrospective analysis of 23 cases of post-traumatic facial nerve injury has been done. Majority of the cases had a conductive or a mixed deafness. The Schirmer's test has been considered to be one of the main indicators to determine the site of injury. The mastoid segment of the facial nerve was found to be injured in 52% of the patients. The surgical approach in patients with post-traumatic facial nerve paralysis should be transmastoid. This can be combined with a middle fossa approach in patients with a positive Schirmer's test.

Facial Nerve↗
PubMed1991

Effect of instant preparation of betel nut (pan masala) on the oral mucosa of albino rats.

Paste made out of an instant betel nut preparation was painted into the oral cavity of 21 albino rats on alternate days for a period of six months. Biopsies were taken from the oral mucosa at the beginning of the study and every two months there after and compared histopathologically with those obtained from a control group of 14 albino rats. Mild to moderate loss of nuclear polarity and increase in keratoses, parakeratoses, inflammatory cell infiltration and vascularity were noted when compared to the control group. The increase in mitotic figures was statistically insignificant and no definite changes in pigmentation or atypical cells were seen. These findings suggest the possibility of mild leukoplakia. Submucosal collagen increased steeply and steadily throughout the study period and at the end of six months, 88.23 per cent of biopsies showed thickened and condensed sub-mucosal collagen, indicating submucous fibrosis.

Animals↗
PubMed1990

Audiovestibular functions in rheumatoid arthritis.

Audiologic, middle ear impedance and vestibular function tests were administered to 25 patients with classical or definite rheumatoid arthritis and 25 normal control subjects of 30 to 50 years age group. Any possible influence of other common causes of hearing loss was avoided by carefully selecting the patients. Six patients had mild sensorineural hearing loss and another had bilateral mixed hearing loss. Results of tone decay test, speech reception threshold, speech discrimination score and short increment sensitivity index tests suggested cochlear pathology being responsible for the sensorineural hearing loss. There was no statistical correlation between hearing loss or otoadmittance abnormality and duration or activity of rheumatoid arthritis or positivity of rheumatoid factor. Electronystagmographic recording of saccades and bithermal caloric induced nystagmus revealed no significant abnormality.

Acoustic Impedance Tests↗
PubMed1989

Computed tomography for determining pathways of extension and a staging and treatment system for juvenile angiofibromas.

Computed tomography (CT) has changed the preoperative assessment protocol of juvenile angiofibromas as it shows the extent of the tumor and its pathways of extension. Hence, operation can be done sooner and with minimal blood loss. Using CT scanning in 22 patients with nasopharyngeal angiofibromas, we found different pathways of extension of the tumor. We report a new staging system and surgical approaches, based on the stage of the tumor.

Adolescent↗
PubMed1989

Brain stem evoked response audiometry in neonates.

Brain stem evoked response audiometry (BERA) was performed in 50 normal full term newborn infants (25 male, 25 female) to generate normative data base for this age group. The stimuli of 30 dB, 40 dB and 80 dB nHL (normal hearing level) intensities were delivered to each subjects. 30 dB stimulus failed to produce clear wave patterns, whereas upto six vertex positive waves were recognised among which waves I, III and V were commonly present. The absolute latencies of waves I and V at 40 dB nJL were 2.54 +/- 0.21 msec and 7.56 +/- 0.26 msec and at 80 dB nHL these were 2.06 +/- 0.15 msec and 7.09 +/- 0.17 msec respectively. I-V interpeak latencies (IPL) were 5.02 +/- 0.13 msec at 40 dB and 5.03 +/- 0.13 at 80 dB nHL. The latencies of waves I and V were decreased with the increase of intensity of stimuli with the rate of 0.012 msec/dB, bit I-V IPL, i.e., central conduction time remained almost constant. There were no statistically significant differences in the brain stem auditory evoked responses between male and female subjects. Brain stem evoked response audiometry is objective and reliable for hearing screening in neonates.

Audiometry, Evoked Response↗
PubMed1989

Post laryngectomy complications and their mode of management--an analysis of 203 cases.

Two hundred and three laryngectomized patients have been evaluated for the possible causes of post operative complications. 58 out of 203 patients (28.5%) developed pharyngocutaneous fistula. Wound infection was present in 57 cases (28%). Two patients had flap necrosis and 12 patients developed dysphagia after surgery due to pharyngeal stenosis. The possible causes attributed to high occurrence of pharyngocutaneous fistula are, advanced nature of disease, preoperative radio therapy and wound sepsis. Prior to 1980, the incidence of pharyngocutaneous fistula in our series (Arora et al. 1983) was 41.6 percent. But it decreased to 13.7 percent between January 1981 to June 1987. The important factors which led to the decreased incidence of pharyngocutaneous fistula were thought to be the change of suture material for pharyngeal repair from chromic catgut to Vicryl, use of vacuum suction as a replacement of corrugated rubber drain and aseptic syringe drainage and postoperative coverage with broad spectrum antibiotics.

Adult↗
PubMed1988

Correlation between high-resolution computed tomography and surgical findings in congenital aural atresia.

Congenital aural atresia poses a great challenge, even to a competent otologic surgeon, due to innumerable types of malformations affecting the conduction and perception of sound. Roentgenographic evaluation by plain roentgenography is inconclusive in most cases; polytomography is helping to some extent. Recent generations of high-resolution computed tomographic (CT) scanners are probably the best. Seven cases of unilateral and three cases of bilateral congenital aural atresia were evaluated with high-resolution CT. Subsequently, ten ears were operated on. Surgical findings were correlated with CT scan findings with respect to atresia plate, extent of pneumatization, ossicular anomalies, bony facial nerve canal, and inner ear. Use of CT scans bears considerable importance in the management of these types of cases. High-resolution CT scan, when targeted for maximal bony detail, is possibly the method of choice in congenital aural atresia when surgical correction is contemplated.

Adolescent↗
PubMed1988

Fungal infections of ear with special reference to chronic suppurative otitis media.

Fungus were found to take important role in ear infections of the 344 patients (CSOM 286, Otomycosis 44, Otitis externa 14), significant fungal infections (with positive smear and culture) were detected on 49%, 79.5%, 66.6% patients respectively. 84.8% patients were detected both by smear and culture, 14.1% patients by culture and 0.1% patients in smear preparation only. In CSOM patients, age predominated in 20-27 yrs group, sex in male below 30 yrs, and Aspergillus flavus, A. niger, Penicillium, A. fumigatus in mycelial fungus, Candida albicans, C. parapsillosis in yeast. But in 18 post antibiotic fungus infected patients Penicillium and A. niger were the important isolates. In otomycosis and otitis externa patients A. niger took the main role.

Adult↗
PubMed1980

Sea-blue histiocytes in idiopathic thrombocytopenic purpura. The first report from the Indian subcontinent.

Sea-blue histiocytes are described in the bone marrow of a 15-year-old male patient suffering from idiopathic thrombocytopenic purpura. Cytochemically the storage material in these cells appeared to be glycophospholipid. Lipid analysis of blood leucocytes and nucleated cells of bone marrow showed a significant increase in the phospholipids, triglycerides and cholesterol as compared to age-matched controls. Serum lipid analysis showed a mild increase of phospholipids as compared to age-matched controls.

Adolescent↗