PubMed Health⌕ Search

Biomedical subjects

M B Shah

Publications and source records attributed to M B Shah.

12 recordsLinked to original sources

Magnetically quantized continuum distorted waves.

A new derivation of continuum distorted-wave theory is presented. It is generalized to magnetically quantized continuum distorted waves. The context is analytic continuation of hydrogenic-state wave functions from below to above threshold, using parabolic coordinates and quantum numbers including m the magnetic quantum number. This continuation applies to excitation, charge transfer, ionization, and double and hybrid events for both light- and heavy-particle collisions. It is applied to the calculation of double-differential cross sections for the single ionization of the hydrogen atom and for a hydrogen molecule by a proton for electrons ejected in the forward direction at a collision energy of 50 keV and 100 keV respectively.

Journal Article↗

The evaluation of the safety and tolerability of two formulations of cyclosporine: neoral and sandimmune. A meta-analysis.

BACKGROUND: Neoral, a microemulsion formulation of cyclosporine, was approved for use in the United States in 1995. Many studies comparing Neoral and Sandimmune have been conducted, and although most state that Neoral is the superior cyclosporine formulation, results have failed to conclusively demonstrate this claim. The aim of this meta-analysis was to compare the safety and efficacy of Neoral and Sandimmune. METHODS: Publications comparing the use of Neoral and Sandimmune were reviewed for demographic variables, adverse events, rejection incidence, graft losses, and serum creatinine. Neoral and Sandimmune were compared in all patients and in the following subgroups: (1) age (adult or pediatric), (2) transplant type (kidney, liver, or heart), (3) indication (de novo or stable), and (4) study design (randomized prospective trials versus nonrandomized, blinded versus open-labeled studies). RESULTS: The rate of graft loss was similar when comparing Neoral and Sandimmune in all analyses. The incidence of rejection was lower in Neoral-treated de novo renal, liver, and cardiac transplants (P<0.05). There were significantly more adverse events in Sandimmune-treated de novo liver transplants than Neoral-treated de novo liver transplants (P<0.00001). When considering only randomized prospective trials, the incidence of rejection was lower in Neoral-treated de novo and stable patients (P<0.05). However, there were more adverse events in Neoral-treated stable patients (P<0.00001). When considering only blinded studies, there were more adverse events in Neoral-treated patients (P<0.05), whereas in open-labeled studies there was no difference in adverse events comparing Neoral and Sandimmune (P=NS). CONCLUSIONS: Considering all published trials, the data seem to indicate that Neoral therapy is preferred because of a lower rejection incidence, with a trend toward less adverse events. However, when limiting the analysis to only randomized prospective trials, and specifically assessing blinded studies, the data become less clear. Neoral use was associated with more adverse events in blinded studies, and Sandimmune use was associated with more adverse events in open-labeled studies. Careful individual consideration must be given in choosing the best possible cyclosporine formulation.

Chemistry, Pharmaceutical↗

An editing environment for DNA sequence analysis and annotation (extended abstract).

This paper presents a computer system for analyzing and annotating large-scale genomic sequences. The core of the system is a multiple-gene structure identification program, which predicts the most "probable" gene structures based on the given evidence, including pattern recognition, EST and protein homology information. A graphics-based user interface provides an environment which allows the user to interactively control the evidence to be used in the gene identification process. To overcome the computational bottleneck in the database similarity search used in the gene identification process, we have developed an effective way to partition a database into a set of sub-databases of "related" sequences, and reduced the search problem on a large database to a signature identification problem and a search problem on a much smaller sub-database. This reduces the number of sequences to be searched from N to O ([square root of] N) on average, and hence greatly reduces the search time, where N is the number of sequences in the original database. The system provides the user with the ability to facilitate and modify the analysis and modeling in real time.

Base Sequence↗

Electron microscope tomography of Balbiani Ring hnRNP substructure.

Three-dimensional (3-D) reconstructions, by electron microscope tomography, of selectively stained, contrast enhanced Balbiani Ring (BR) hnRNP granules reveal a complex spatial arrangement of RNA-rich domains. This particulate substructure was examined by volume rendering computer graphics. Modeling the arrangement of RNA-rich domains is made difficult by apparent structural flexibility and/or heterogeneity of composition. Formulation of a consensus 3-D arrangement of RNA-rich domains will require an expanded data base of reconstructed BR granules and the development of new image manipulation and analysis techniques. This study demonstrates the potential for ultrastructural cell biology of combining several new techniques: selective nucleic acid staining, electron spectroscopic imaging to enhance contrast, electron microscope tomography and volume rendering computer graphics.

Animals↗

Endocrine changes in Alzheimer's disease.

In conclusion, at present, no consistent endocrine abnormalities can be detected in patients suffering from Alzheimer's disease. However, assessment of neuroendocrine function might help identify subpopulations of patients with particular neurotransmission abnormalities who are likely to benefit from a specific pharmacologic strategy. For example, patients in whom cholinomimetic drugs produce the greatest elevation in plasma cortisol concentration appear to derive the most symptomatic benefit from these drugs.

Alzheimer Disease↗

Endocrine changes in Alzheimer's disease.

In conclusion, at present, no consistent endocrine abnormalities can be detected in patients suffering from Alzheimer's disease. However, assessment of neuroendocrine function might help identify subpopulations of patients with particular neurotransmission abnormalities who are likely to benefit from a specific pharmacologic strategy. For example, patients in whom cholinomimetic drugs produce the greatest elevation in plasma cortisol concentration appear to derive the most symptomatic benefit from these drugs.

Alzheimer Disease↗

Stereoacuity testing in patients with retinal and optic nerve disorders.

A study comparing the relative sensitivity for detecting abnormal stereoacuity in patients with retinal or optic nerve disease on clinically used stereoacuity tests is not available. It is also not apparent from the ophthalmic literature if optic nerve or retinal diseases are likely to have a greater impact on stereoacuity performance. We were also interested in determining a level of visual acuity loss that would likely results in an impairment of stereoacuity on these clinical tests. Forty-two patients with various retinal and optic nerve disorders and eighteen normal subjects were evaluated for stereoacuity using three tests: Titmus Stereoacuity Test (TST), Randot Stereoacuity Test (RST), and TNO Stereoacuity Test (TNO). The performance on these three stereoacuity tests was compared with the normal subjects. Additionally, TST scores from our patients were compared to predicted TST scores derived from a previously published nomogram. For patients with retinal and optic nerve disease, an abnormal score on one clinical test of stereoacuity was likely to predict an abnormality on the other tests. Performance on the TST relative to the predicted value derived from a nomogram was not significantly different for patients with retinal vs. optic nerve disease. With some exceptions, patients with visual acuities of 20/30 or worse in at least one eye were likely to show abnormal stereoacuity.

Adolescent↗