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Biomedical subjects

S A Haider

Publications and source records attributed to S A Haider.

At least 19 recordsLinked to original sources
PubMed2001

Intraocular vancomycin levels after intravitreal injection in post cataract extraction endophthalmitis.

PURPOSE: Intravitreal antibiotics are the mainstay of treatment of endophthalmitis following cataract surgery. The purpose of this study is to determine the range of intraocular vancomycin found after intravitreal therapy and assess the optimum time for repeat injections. METHODS: Aqueous and vitreous vancomycin was assayed at the time of reinjection in 14 patients with endophthalmitis showing a poor clinical response after their primary injection. Nine patients received vancomycin 2 mg and another five received vancomycin 1 mg. In six patients the injection was repeated at 48 hours and in seven at 72 hours. Two patients received three injections. RESULTS: Aqueous vancomycin varied from 8.4 to 170 mg/L and the vitreous vancomycin level ranged from 21.2 to 220 mg/L. CONCLUSIONS: In the current study vitreous vancomycin levels were variable, but well within the therapeutic range for sensitive Gram-positive organisms. At times they exceeded the putative retinotoxic levels (100 mg/L). Higher aqueous levels were found after an injection of 2 mg than after 1 mg. Vancomycin levels were still very high 3 days after injection of 2 mg where results were available. Assay at the time of repeat injection may provide insight into the adequacy of vitreous levels and guide future therapy.

Aged↗
PubMed2000

Abdominal aortic aneurysm with aorta-left renal vein fistula with left varicocele.

Abdominal aortic aneurysm with spontaneous aorto-left renal vein fistula is a rare but well-described clinical entity usually with abdominal pain, hematuria, and a nonfunctioning left kidney. This report describes a 44-year-old man with left-sided groin pain and varicocele who was treated with conservative measures only. The diagnosis was eventually made when he returned with microscopic hematuria, elevated serum creatinine level, and nonfunction of the left kidney; computed tomography scan demonstrated a 6-cm abdominal aortic aneurysm, a retroaortic left renal vein, and an enlargement of the left kidney. This patient represents the youngest to be reported with aorto-left renal vein fistula and the second case with a left-sided varicocele.

Abdominal Pain↗
PubMed1995

Consequences of cometary aurora on the carbon chemistry at comet P/Halley.

Various experimental data acquired during the visit of Halley's comet in 1986 have shown that the amount of carbon produced due to photodissociation of parent carbon bearing species is not ample enough to explain the observations. This requires the presence of an additional source of atomic carbon. One of the possible source could be auroral-type activities resulting from the precipitation of high-energy "auroral electrons" of solar wind origin, the evidence of which have been inferred from many observations at comet Halley. We have developed a coupled chemistry-transport model to study the role of auroral and photoelectron impact as well as of chemistry on the modelling of carbon in the inner coma (< or = 10(4) km) of comet Halley. Our study suggest that electron impact dissociation of CO is the major source of carbon production in the inner coma, not the recombination of CO+ as suggested by earlier workers, while transport is the main loss process.

Carbon↗
PubMed1993

Temperature distribution in tissues from a regular array of hot source implants: an analytical approximation.

An approximate analytical model based upon the bioheat transfer equation is derived and used to calculate temperatures within a perfused region implanted regularly with dielectrically coated hot source implants; for example, hot water tubes, electrically heated rods, or inductively heated ferromagnetic implants. The effect of a regular array of mutually parallel heat sources of cylindrical shape is approximated by idealizing one of the boundary conditions. The solution, as could be expected, is in terms of modified Bessel functions. In calculating the temperature of each thermoregulating source in the array, the steady state power balance is enforced. The important feature of the model is that the finite size of implant diameter and its dielectric coating can be incorporated. The effect of thickness and thermal conductivity of the coating on the source and tissue temperatures along with various other interesting features are deduced from this model. The analytically calculated implant and tissue temperatures are compared with those of a numerical 3-D finite difference model. The analytical model also is used to define a range of parameters such that minimal therapeutic temperatures will be achieved in the implanted volume without exceeding prescribed maximum temperatures. This approach leads to a simple means of selecting implant spacing and regulation temperatures of hot source methods prospectively.

Blood Flow Velocity↗
PubMed1992

Lid melanoma and parkinsonism.

This is a case report of a patient with parkinsonism on levodopa therapy who developed a lid margin melanoma. The possible association is discussed.

Aged↗
PubMed1981

Aminoaciduria in handicapped children: a study using ion-exchange chromatography as a screening test.

The aminoacid excretion levels of 59 normal and 75 physically and/or mentally handicapped children were measured with ion-exchange chromatography. A computer-assisted statistical analysis of the results from the normal population was used to calculate an approximating frequency distribution. 18 patients were found to be excreting one or more aminoacids above the normal 99.75th or 100th percentiles. They included 1 with dibasic aminoaciduria; 1 six-year-old with phenylketonuria; 1 with hyperphenylalaninuria; 5 with cystathioninuria; 2 with hyperglycinuria; 1 with hyperglycinuria and hypertaurinuria; 5 with hypertaurinuria; 1 excreting high levels of taurine, serine, tyrosine, and histidine, and 1 with asparaginuria.

Amino Acids↗
PubMed1977

Treatment of atopic eczema in children: clinical trial of 10% sodium cromoglycate ointment.

In a double-blind randomised group-comparative trial 21 children with chronic atopic eczema were treated twice daily for up to 12 weeks with an ointment containing 10% sodium cromoglycate (SCG) in white soft paraffin. A similar group of 21 children was treated for up to 12 weeks with a placebo ointment consisting of the white soft-paraffin base only. The number of patients who withdrew from the trial because treatment was ineffective was significantly greater in the placebo group (16) than in the SCG group (four). Comparison between the two groups also showed significant improvement in inflammation, lichenification, and cracking and the symptoms of itching and sleep disturbance among those on SCG treatment. At the end of treatment significantly more patients in the SCG group (16) had benefited from treatment compared with only two patients in the placebo group. No patients experienced side effects. I conclude that SCG ointment may be a safe alternative to topical steroids in the treatment of atopic eczema in children.

Administration, Topical↗
PubMed1977

Alkali denaturation of oxyhaemoglobins of some digenetic trematodes and their hosts.

Oxyhaemoglobins of six digenetic trematodes,--Srivastavaia indica, Gastrothylax crumenifer, Gigantocotyle explanatum, Fasciolopsis buski, Gastrodiscoides hominis, Isoparorchis hypselobagri, and of their 3 vertebrate hosts, Bubalus bubalis, Sus scrofa, Wallago attu, were subjected to alkali denaturation at a pH of 12.4. All oxyhaemoglobins from trematodes and their hosts differ from each other in the rate and extent of alkali denaturation which may be explained due to variations in the amino acid sequences of a particular haem protein in addition to other factors.

Alkalies↗
PubMed1976

Spectrophotometric analysis of haemoglobins of some digenetic trematodes and their hosts.

The haemoglobins of six different species of trematodes: Gastrothylax crumenifer, Srivastavaia indica, Gigantocotyle explanatum, Fasciolopsis buski, Gastrodiscoides hominis, Isoparorchis hypselobagri and their three different hosts: Bubalus bubalis, Sus scrofa, and Wallago attu were spectrophotometrically investigated, and were found to contain porphyrin IX as the common prosthetic group. Oxyhaemoglobin, carbonmonoxy-haemoglobin and reduced haemoglobin of all 6 species of trematodes and their 3 hosts under study gave similar absorption maxima. Distinct differences were, however, observed in the nature of the spectral curves of cyanmethaemoglobin which exhibit 2 absorption maxima in the beta and the alpha region in the case of all trematodes whereas in the case of similar host haemoglobin derivatives only one single broad peak in the 536-540 nm region was obtained. With respect to pyridine derivatives all the trematode haemoglobins show a sharp peak in the alpha region and a minor hump in the beta region except Gastrothylax crumenifer. All three host pyridine haemoglobin derivatives show only a single broad peak at 570 nm.

Animals↗