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Biomedical subjects

M Goyal

Publications and source records attributed to M Goyal.

At least 73 records · Page 4Linked to original sources
PubMed1997

Simultaneous detection and strain differentiation of Mycobacterium tuberculosis for diagnosis and epidemiology.

Widespread use of DNA restriction fragment length polymorphism (RFLP) to differentiate strains of Mycobacterium tuberculosis to monitor the transmission of tuberculosis has been hampered by the need to culture this slow-growing organism and by the level of technical sophistication needed for RFLP typing. We have developed a simple method which allows simultaneous detection and typing of M. tuberculosis in clinical specimens and reduces the time between suspicion of the disease and typing from 1 or several months to 1 or 3 days. The method is based on polymorphism of the chromosomal DR locus, which contains a variable number of short direct repeats interspersed with nonrepetitive spacers. The method is referred to as spacer oligotyping or "spoligotyping" because it is based on strain-dependent hybridization patterns of in vitro-amplified DNA with multiple spacer oligonucleotides. Most of the clinical isolates tested showed unique hybridization patterns, whereas outbreak strains shared the same spoligotype. The types obtained from direct examination of clinical samples were identical to those obtained by using DNA from cultured M. tuberculosis. This novel preliminary study shows that the novel method may be a useful tool for rapid disclosure of linked outbreak cases in a community, in hospitals, or in other institutions and for monitoring of transmission of multidrug-resistant M. tuberculosis. Unexpectedly, spoligotyping was found to differentiate M. bovis from M. tuberculosis, a distinction which is often difficult to make by traditional methods.

Bacterial Typing Techniques↗
PubMed1997

Rapid detection of multidrug-resistant tuberculosis.

Transmission of multidrug-resistant strains of Mycobacterium tuberculosis (MDR-TB) presents a serious problem for infection control in hospitals, particularly in the context of co-infection with the human immunodeficiency virus (HIV). We report on the use of molecular genetic tools to allow rapid assessment of samples from patients potentially infected with MDR-TB. Sputum and bronchoalveolar lavage samples were obtained from two HIV-positive patients with suspected tuberculosis, who had previous contact with a known MDR-TB index case. Polymerase chain reaction (PCR) was used directly on clinical samples to amplify genetic loci associated with rifampicin resistance (rpoB), and strain-specific polymorphisms (the direct repeat (DR) region). Drug resistance was determined using a commercially available kit for detection of point mutations in the rpoB gene (Inno-Lipa RifTB; Innogenetics, Belgium), and confirmed by nucleotide sequencing. Strain variation was determined using the spoligotyping method, based on the presence or absence of variable linker sequences within the DR region. In one patient, infection with a MDR strain identical to that of a known index case was demonstrated. A second patient, although positive for M. tuberculosis, was found to be infected with a rifampicin-sensitive strain. Results were obtained within 48 h, allowing appropriate treatment to be initiated and infection control measures to be implemented. PCR-based tests for strain-typing and for identification of rifampicin resistance provide important tools for identifying patients with MDR-TB and for rapid monitoring of potential nosocomial spread of MDR-TB. Prompt confirmation or exclusion of possible transmission allows early clinical intervention to prevent future outbreaks of multidrug-resistant M. tuberculosis.

Antibiotics, Antitubercular↗
PubMed1997

MR imaging of tubercular spinal arachnoiditis.

OBJECTIVE: The purpose of our study was to examine the spectrum of abnormalities seen on MR imaging in patients with tubercular spinal arachnoiditis. MATERIALS AND METHODS: A retrospective analysis of MR findings in 22 cases of tubercular spinal arachnoiditis was carried out. The diagnosis had been established on the basis of clinical features, evidence of associated tubercular meningitis or of tubercular spondylitis, and CSF analysis. RESULTS: Nineteen (86%) patients had involvement of more than one spinal region, with the dorsal region being most commonly involved. CSF showed increased signal intensity on T1-weighted images in 17 (77%) patients, leading to complete loss of cord-CSF interface in seven patients and shaggy cord outline in 10 patients. As suggested by increased signal intensity on T2-weighted images, we saw cord involvement in 18 (82%) patients. Three of these patients had evidence of cord cavitation. Other findings seen on unenhanced images were CSF loculations in five patients, nodules in subarachnoid space in six patients, and clumping of cauda equina nerve roots in six patients. Contrast-enhanced studies were available in 20 patients. Meningeal enhancement was seen in 16 (80%) of 20 patients, and nerve root enhancement was seen in six (30%) patients. Cord enhancement was seen in four (20%) of 20 patients. Enhancement was observed along the surface of the cord in two of these patients, whereas the other two patients showed central enhancement. Associated findings were tubercular spondylitis in two patients, basal exudate in eight patients, and intracranial granulomas in five patients. CONCLUSION: MR imaging revealed several pathologic changes that occur in patients with tubercular spinal arachnoiditis and, hence, may play an important role in the diagnosis of this entity.

Adult↗
PubMed1997

Imaging appearance of pachymeningeal tuberculosis.

OBJECTIVE: The purpose of our study was to examine imaging findings in patients with pachymeningeal tuberculosis. Imaging studies of seven patients with pachymeningeal tuberculosis were retrospectively reviewed. The diagnosis had been established on the basis of histopathology in three patients and response to antitubercular treatment in four patients. CONCLUSION: Tuberculosis can lead to localized or diffuse involvement of the pachymeninges. Most of the focal lesions were seen as en plaque, homogeneous, uniformly enhancing, dural-based masses. The lesions appeared hyperdense on plain CT scans, isointense to brain parenchyma on T1-weighted MR images, and isointense to hypointense on T2-weighted MR images. One patient had diffuse sheet-like thickening of the pachymeninges in the right hemicranium, involving both the supratentorial and infratentorial compartments.

Adult↗
PubMed1997

Fantasy and reality distinction of congenitally blind children.

40 congenitally blind and 40 sighted children were tested for fantasy-reality distinctions of real and imagined objects and the development of concepts of darkness, hidden objects, space, dreams, emotions, facial expressions, size, and height. Analysis indicated that the blind children distinguished between contents of fantasy and reality, although they were less sure about the reality status of the objects. The sighted group gave more reality responses than the blind group for the concepts of dreams and hidden objects, but the remaining concepts were somewhat the same. Cognitive development explained in terms of theory formation may not explain the development of young blind children completely. Their knowledge that contents of fantasy are not real may be obtained through interpersonal experiences that are publicly shared.

Blindness↗
PubMed1996

Cervical intramedullary lipoma with unusual MRI features: case report.

Intramedullary (subpial) lipomas not associated with spinal dysraphism are very unusual [1]. A confident preoperative diagnosis is usually possible with MRI. We present a case of an isolated cervical intramedullary lipoma with unusual imaging morphology and imaging characteristics (distinctly low-signal on T2-weighted images) on MRI. An explanation for these features is proposed.

Adult↗
PubMed1996

Proton MRS in Pott's spine--a case report.

Proton Magnetic Resonance Spectroscopy was carried out at 1.5 T on a patient with histologically proven Pott's spine affecting D11 vertebral body. In addition to the significantly reduced signals from the lipids in the region between 1 and 2 ppm, a prominent resonance at 5.1 ppm is seen. The spectrum is very different from that recorded on the one hand for a normal spine and, on the other, for a tumor arising from the vertebral body of a patient.

Adult↗
PubMed1996

Reassessment of nonplanimetric transrectal ultrasound prostate volume estimates.

OBJECTIVES: To assess the accuracy and reproducibility of nonplanimetric transrectal ultrasound (TRUS) volume estimates because inaccurate volume estimates may potentially undermine the value of serum prostate-specific antigen density (PSAD) in early prostate cancer detection. METHODS: We prospectively evaluated 535 consecutive male patients with two consecutive volume determinations performed by the same ultrasonographer at the time of the same visit. RESULTS: Pearson correlation coefficients between two consecutive gland volume estimates ranged from 0.82 to 0.85 depending on the formula used; however, these correlation coefficients corresponded to an average 25% difference between the first and second gland volume estimates. CONCLUSIONS: Although two consecutive nonplanimetric TRUS volume estimates show statistically good correlation, clinically up to a 25% volume difference should be expected between two such volume estimates. In consequence, nonplanimetric TRUS volume estimates should be interpreted with caution, especially when used for PSAD calculation, in the early detection of prostate cancer.

Adult↗
PubMed1996

A follow-up study on visual outcome after camp-based intracapsular cataract extraction.

The visual outcome of 164 intracapsular cataract extractions (ICCE) performed in 158 patients at an eye-camp was evaluated. 93.3% had a preoperative visual acuity of less than 3/60. On the 4th/5th post-operative day, 39.3% had a visual acuity between 6/18 and 6/36; 84.7% had vision better than 3/60. Six weeks post-operatively, 44.1% had visual acuity better than 6/18 and a total of 84.1% better than 3/60. The vision of 40.7% improved between the 4th/5th post-operative day and the follow-up visit at 6 weeks. 46.4% of patients had post-operative corrected visual acuity better than 6/18, 24.3% had vision between 6/18 and 6/36, and a total of 84.3% had vision better than 3/60. The patients' satisfaction in terms of improvement in mobility and ability to do housework at 6 weeks after the operation correlated better with the improvement in vision in terms of the number of Snellen's lines than with the actual post-operative visual acuity.

Aged↗
PubMed1996

Comparison of polymerase chain reaction for IS6110 and Amplicor in the diagnosis of tuberculosis.

BACKGROUND: Polymerase chain reaction (PCR) amplification of Mycobacterium tuberculosis DNA offers the potential of a sensitive and specific diagnostic test for tuberculosis. To evaluate this technique from the clinician's perspective, samples were collected from patients with chronic respiratory disease and the sensitivity and specificity of a newly introduced commercially available PCR kit (Amplicor) was compared with that of an established method to detect the target sequence IS6110. METHODS: Sputum or bronchial washings from patients with active tuberculosis, previously treated tuberculosis or other selected respiratory illnesses were analysed by both techniques and their sensitivity and specificity determined. RESULTS: Amplicor was more specific than IS6110 in the diagnosis of active infection (98% versus 79%). Both techniques were equally sensitive (92%). CONCLUSION: These results suggest that analysis of respiratory samples by Amplicor PCR in inner city populations of patients has greater specificity for a diagnosis of active tuberculosis than PCR for IS6110, and thus Amplicor PCR may aid the clinician in making a diagnosis of active tuberculosis.

Base Sequence↗
PubMed1996

Value of systematic transition zone biopsies in the early detection of prostate cancer.

PURPOSE: A prospective study was done to determine the value of performing 2 systematic transition zone biopsies in addition to systematic sextant peripheral zone biopsies for early detection of prostate cancer. MATERIALS AND METHODS: From January 1 to August 31, 1994 we evaluated 847 consecutive patients referred to us for a suspicious lesion on digital rectal examination or an elevated serum prostate specific antigen level. All patients underwent 2 systematic transition zone biopsies in addition to systematic sextant biopsies of the peripheral zone. RESULTS: Of the transition zone biopsies 68 (24.4%) contained malignancy, including only 8 (2.9%) with cancer found exclusively in the transition zone. The remaining 271 cases (97.1%) had 1 or more positive peripheral zone biopsies and would have been detected with or without additional systematic transition zone biopsies. The same analysis of 552 patients with a negative digital rectal examination yielded 6 (4.1%) exclusively transition zone tumors among 145 cancers detected in this group. CONCLUSIONS: The low additional yield of transition zone biopsies (2.9 to 4.1%) does not warrant their systematic use for the early detection of prostate cancer.

Adult↗