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Biomedical subjects

M Baig

Publications and source records attributed to M Baig.

At least 19 recordsLinked to original sources

Optimal scheme for estimating a pure qubit state via local measurements.

We present the optimal scheme for estimating a pure qubit state by means of local measurements on N identical copies. We give explicit examples for low N. For large N, we show that the fidelity saturates the collective measurement bound up to order 1/N. When the signal state lays on a meridian of the Bloch sphere, we show that this can be achieved without classical communication.

Journal Article↗

Aligning reference frames with quantum states.

We analyze the problem of sending, in a single transmission, the information required to specify an orthogonal trihedron or reference frame through a quantum channel made out of N elementary spins. We analytically obtain the optimal strategy, i.e., the best encoding state and the best measurement. For large N, we show that the average error goes to zero linearly in 1/N. Finally, we discuss the construction of finite optimal measurements.

Journal Article↗

Optimal strategies for sending information through A quantum channel

Quantum states can be used to encode the information contained in a direction, i.e., in a unit vector. We present the best encoding procedure when the quantum state is made up of N spins (qubits). We find that the quality of this optimal procedure, which we quantify in terms of the fidelity, depends solely on the dimension of the encoding space. We also investigate the use of spatial rotations on a quantum state, which provide a natural and less demanding encoding. In this case we prove that the fidelity is directly related to the largest zeros of the Legendre and Jacobi polynomials. We also discuss our results in terms of the information gain.

Journal Article↗

A modified submental approach for oral endotracheal intubation.

Hernandez, in 1986, published the first paper on "The submental route for endotracheal intubation". The technique was developed to avoid tracheostomy, particularly in maxillofacial trauma cases, where short-term intermaxillary fixation was required. Gordon & Tolstunov published 2 cases utilizing the technique. Our initial experience with the technique as presented was less than satisfactory. The technique was modified to utilize a strict midline approach. Fifteen cases utilizing this modified technique are reported, including 14 cases of craniomaxillofacial trauma and one complex orthognathic surgery case. There have been no operative or postoperative complications. Postoperative submental scarring has been acceptable.

Chin↗

Vessel dilator enhances sodium and water excretion and has beneficial hemodynamic effects in persons with congestive heart failure.

BACKGROUND: Vessel dilator, a 37-amino acid peptide hormone synthesized in the heart, enhances urine flow 4- to 12-fold and sodium excretion 3- to 6-fold in healthy humans. The present investigation was designed to determine whether vessel dilator might have similar beneficial effects in persons with congestive heart failure (CHF). METHODS AND RESULTS: Vessel dilator (100 ng/kg body weight per minute) given intravenously for 60 minutes to NYHA class III CHF subjects increased urine flow 2- to 13-fold, which was still increased (P<0.001) 3 hours after its infusion was stopped. Vessel dilator enhanced sodium excretion 3- to 4-fold in CHF subjects (P<0.01), which was still significantly (P<0.01) elevated 3 hours after infusion. Vessel dilator decreased systemic vascular resistance 24%, pulmonary vascular resistance 25%, pulmonary capillary wedge pressure 33%, and central venous pressure 27% while increasing cardiac output 34%, cardiac index 35%, and stroke volume index 24% without significantly affecting heart rate or pulmonary artery pressure in the CHF subjects. The control CHF patients did not have any changes in the above parameters. CONCLUSIONS: These results indicate that vessel dilator has significant beneficial diuretic, natriuretic, and hemodynamic properties in humans with congestive heart failure.

Adult↗

Production of monoclonal antibodies against Nosema bombycis and their utility for detection of pebrine infection in Bombyx mori L.

Latex agglutination assay based on monoclonal antibodies (MCAs) described in this communication may be useful for detection of Pebrine infection in silkworm. Four murine MCAs were produced against Nosema bombycis spore. In ELISA all 4 MCAs (IgM isotype) reacted with alkali treated Nosema spores and to variable extent with acetone precipitated surface protein. However, MA-310 and MA-542 showed a low degree of cross reactivity with BmNPV. In contrast, MA-503 and MA-515 were devoid of reactivity with BmNPV, B. thuringiensis, S. marcescens, Azotobactor, Rhizobium and normal hemolymph protein in ELISA. Latex beads sensitized with a combination of MA-503 and MA-515 (50 micrograms each per ml of 0.4% latex beads) could detect 1 x 10(5) Nosema spores per test. Sensitization of the latex beads with the cocktail of these two MCAs through protein-A bridge further led to a 10-fold increase in the sensitivity (1 x 10(4) spores/test) of the assay. No agglutination was observed in presence of BmNPV, Rhizobium, Azotobactor, E. coli, B. thuringiensis, S. marcescens and normal hemolymph protein indicating the specificity of the test. The results obtained by latex agglutination assay on hemolymph samples of infected as well as normal larvae collected from field, II instar larvae infected in the laboratory and from infected mother moth revealed 100% correlation with results by microscopic examination.

Animals↗

Management of acute renal failure in the elderly. Treatment options.

Renal changes that occur with aging mainly consist of impairment in the ability to concentrate urine and to conserve sodium and water. These physiological changes increase the risk of volume depletion and the prerenal type of acute renal failure (ARF) in elderly people. Bladder outlet obstruction caused by benign prostatic hypertrophy is a common cause of ARF in elderly men. Another frequent cause of ARF in the elderly is drug-induced nephropathy. Nonsteroidal anti-inflammatory drugs (NSAIDs) and antibiotics are most often implicated in the development of ARF in the elderly. However, considering the high usage of these drugs, the incidence of drug-induced nephropathy is relatively small. NSAIDs are more likely to cause ARF in patients with congestive heart failure, chronic renal disease (including diabetic nephropathy) or chronic liver disease than in otherwise healthy individuals. NSAID-induced ARF is often of the prerenal type, but may be caused by acute interstitial nephritis (AIN). The presence of heavy proteinuria or nephrotic syndrome differentiates NSAID-induced AIN from AIN caused by other drugs. Antibiotics, especially semisynthetic penicillins, more commonly give rise to AIN associated with peripheral blood eosinophilia and eosinophiluria than NSAIDs. Ciprofloxacin is increasingly reported to cause AIN. Fever commonly accompanies AIN, especially when induced by antibiotics. Aminoglycosides produce ARF by inducing acute tubular necrosis (ATN), which results from the excessive accumulation of myeloid bodies in the tubules. In all cases of ARF it is essential to obtain a good history, to perform a through physical examination, with particular attention to skin turgor, and to measure blood pressure, pulse rate (supine and upright), urinary electrolyte and creatinine levels. Fractional excretion of sodium and the urine:plasma creatinine ratio are reliable indices that distinguish prerenal ARF from ATN. A prompt response to fluid challenge, with an increase in urine output and urinary sodium excretion, and a rapid decrease in blood urea nitrogen, constitutes strong evidence for prerenal ARF. However, these indices are unreliable when prerenal ARF has progressed to ATN or when ARF has an obstructive pattern to begin with. In all cases of ARF, especially in elderly men, urinary tract obstruction should be suspected unless the history is otherwise clear cut. Ultrasound of the kidneys and bladder is a simple, non-invasive and meaningful test that can be used to rule out obstructive causes of ARF. If obstruction is the cause of ARF, ultrasound will be positive; in contrast, urinary obstruction is very unlikely if ultrasound findings are normal in a patient who has been oliguric or anuric for 48 hours or more. Similarly, acute glomerulonephritis, including rapidly progressive glomerulonephritis, should be suspected when ARF is associated with heavy proteinuria. In such instances, percutaneous renal biopsy is essential to document the diagnosis. It is of utmost importance to establish whether ARF is of prerenal or postrenal type, both of which are potentially fully reversible. In contrast, patients with ATN or rapidly progressive glomerulonephritis may not recover, or may only partially recover, their renal function. Haemodialysis and nutritional support are common measures for patients with severe ATN and a highly catabolic state. Corticosteroids and immunosuppressive therapy should be instituted for rapidly progressive glomerulonephritis, in addition to haemodialysis. haemodiafiltration instead of haemodialysis is recommended for patients who are haemodynamically unstable [i.e., with a persistently low blood pressure (systolic < or = 100 mm Hg)]. Haemodiafiltration has been shown to improve acid-base balance and uraemia better than standard haemodialysis. However, despite dialysis, mortality in patients with ARF associated with ischaemic ATN remains high.

Acute Kidney Injury↗

Evaluation of protein-A linked monoclonal antibody latex agglutination test for diagnosis of nuclear polyhedrosis virus (BmNPV) of silkworm Bombyx mori L.

The symptomology of BmNPV infection in Bombyx mori L depends on the stages of infection. Discernible symptoms develop at later stages of infection, which leads to improper diagnosis and poor crop yield with sericulturists. In the present study development of direct and protein-A linked monoclonal antibody latex (PALMAL) agglutination test for the detection of BmNPV infection in silkworm is described. Latex beads were precoated with protein-A and then sensitised with monoclonal antibody MA-231 (125 micrograms/ml). PALMAL test could detect 1 x 10(5) nuclear polyhedra/test and is ten times more sensitive than the direct agglutination test employing purified polyclonal antibodies. No agglutination was observed in presence of B. thuringiensis, S. marcescens, N. bombycis, group-A streptococci, Staphylococcus aureus, E. coli and normal haemolymph protein indicating the specificity of the test. Fifty haemolymph samples collected from the field were evaluated by PALMAL test. Twenty one samples having infection other than BmNPV, failed to show positive agglutination. Twenty five samples having > or = 5 x 10(6) BmNPV/ml showed positive agglutination. However, 4 samples having < 5 x 10(6) BmNPV/ml failed to show positive agglutination thereby indicating the limit of sensitivity of the assay.

Animals↗

Differential expression of the myocyte enhancer factor 2 family of transcription factors in development: the cardiac factor BBF-1 is an early marker for cardiogenesis.

In the present study, we have used single chicken blastoderms of defined early developmental stages, beginning with the prestreak stage, stage 1 (V. Hamburger and H. L. Hamilton, J. Morphol. 88:49-92, 1951), to analyze the onset of cardiac myogenesis by monitoring the appearance of selected cardiac muscle tissue-specific gene transcripts and the functional expression of the myocyte enhancer factor 2 (MEF-2) proteins. Using gene-specific oligonucleotide primers in reverse transcriptase PCR assay, we have demonstrated that the cardiac myosin light-chain 2 (MLC2) and alpha-actin gene transcripts appear as early as stage 5, i.e., immediately after the cardiogenic fate assignment at stage 4. Consistent with this observation is the developmental expression pattern of DNA-binding activity of BBF-1, a cardiac muscle-specific member of the MEF-2 protein family, which also begins at stage 5 prior to MEF-2. Differential expression of DNA-binding complexes is also observed with another AT-rich DNA sequence (CArG box) as probe, but the binding pattern with the ubiquitous TATA-binding proteins remains unchanged during the same developmental period. Thus, the cardiogenic commitment and differentiation of the precardiac mesoderm, as exemplified by the appearance of cardiac MEF-2, MLC2, and alpha-actin gene products, occur earlier than previously thought and appear to be closely linked. The onset of skeletal myogenic program follows that of the cardiogenic program with the appearance of skeletal MLC2 at stage 8. We also observed that mRNA for the MEF-2 family of proteins appears as early as stage 2 and that for CMD-1, the chicken counterpart of MyoD, appears at stage 5. The temporal separation of activation of cardiac and skeletal MLC2 genes, which appears immediately after the respective fate assignments, and those of cardiac MEF-2 and CMD-1, which occur before, are consistent with the established appearance of the myogenic programs and with the acquisition pattern of the two tissue-specific morphological characteristics in the early embryo. The preferential appearance of BBF-1 activity in precardiac moesderm, relative to that of MEF-2, indicates that these two protein factors are distinct members of the MEF-2 family and provides a compelling argument in support of the potential role of BBF-1 as a regulator of the cardiogenic cell lineage determination, while cardiac MEF-2 might be involved in maintenance of the cardiac differentiative state.

Age Factors↗

Temperature correction factors derived from normal subjects may be invalid in demyelinating neuropathies.

This study investigates the temperature effect on motor nerve conduction velocity (MNCV) in patients with neuropathic processes. Fourteen subjects, ages 18-77 yr old, with a diagnosis of uremic polyneuropathies (UPN, n = 5), diabetic polyneuropathies (DPN, n = 6) or carpal tunnel syndrome (CTS, n = 3) and ten normal controls were studied. After limb cooling in a cold water bath for 30 min, skin temperatures were sequentially obtained from the volar midwrist. Motor conduction velocities were obtained at 2-3 degrees increments between 22 and 33 degrees C. Results indicated a large individual variability; 0.1 to 1.8 in the median and 0.8 to 2.0 m/s/degrees C in the ulnar nerve when all three groups are considered together. There was a significant difference between the correction factors for control v DPN and control v CTS. A significant difference was also present for UPN v DPN and UPN v CTS (p < 0.05). There was a positive correlation (r = 0.746, p = 0.0001) between the baseline conduction velocities and the size of the correction factors in all the subjects. The effect of temperature on MNCV appears to be inversely correlated with the severity of conduction slowing or demyelination. These findings suggest that the use of a correction factor may be invalid when studying a demyelinated nerve, and that the extremity should be warmed to a specific temperature before an electrodiagnostic study.

Adolescent↗