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Biomedical subjects

M Riaz

Publications and source records attributed to M Riaz.

At least 37 records · Page 2Linked to original sources

Early active mobilization after second stage flexor tendon grafts.

We assessed the results of nine two-stage tendon reconstructions. The tendon graft was the ipsilateral palmaris longus tendon inserted into a tunnel which had been previously created by a silicone spacer. Early active mobilization was commenced 48 hours after surgery according to a previously described protocol (Small et al, 1989). Using the grading system of Kleinert and Verdan (1983) the results were: one excellent, two good, five fair and one poor. Using the Buck-Gramcko et al (1976) grading system there were three excellent, two good, two satisfactory and two poor results. There were no cases of tendon graft rupture or dehiscence of the junction between tendon and graft.

Adult↗

Florid reactive periostitis of the thumb.

A case of florid reactive periostitis of the thumb is presented. This is a rare pseudosarcomatous lesion which generally has a benign radiographic appearance, but on histology it may be mistaken for a malignant process. The clinical behaviour may simulate a malignant tumour but after local excision there is very little propensity for recurrence. Local resection is the recommended treatment. Surgeons and pathologists should consider the possibility of florid reactive periostitis before making a diagnosis of sarcoma in the hand.

Humans↗

Liposomes preparation methods.

In this article information about various methods of liposome preparation (including the large scale manufacture) has been reviewed. The advantages and disadvantages of the methods have been described in terms of size distribution and encapsulation efficiency.

Journal Article↗

Prevalence of sand fly fever, West Nile, Crimean-Congo hemorrhagic fever, and leptospirosis antibodies in Pakistani military personnel.

To determine the prevalence of antibodies to viral diseases known or suspected to be present in Pakistan, we studied 570 sera from three groups of adults; two of the groups were involved in outbreaks of hepatitis, and the third included men admitted to a hospital for evaluation of febrile illnesses. Immunoglobulin G antileptospiral antibody was found in 1 to 6% of the subjects, with the highest rate in enlisted military personnel hospitalized for febrile illness. One man in the group with febrile illness had significantly elevated immunoglobulin M antileptospiral antibody titers. However, in a group of recruits experiencing suspected non-A, non-B hepatitis, 19 (11%) of 173 had a 4-fold rise in immunoglobulin M antibody to leptospirosis. Antibody to sand fly fever viruses was found in 27 to 70%. Antibody to West Nile virus was present in 33 to 41% of subjects. Antibody reactive with Japanese encephalitis virus was present in 25%, but plaque reduction neutralization tests suggested this to be cross-reaction with West Nile virus. All 212 specimens tested for antibody to Crimean-Congo hemorrhagic fever and Hantaan viruses were negative. This study indicates that diseases known to be prevalent in other areas of southwest Asia and the Middle East are also prevalent in northern Pakistan and may impact on those traveling or working in this area.

Adolescent↗

Stability of phosphoinosit1des containing liposomes: effects of triton x-100, temperature and 68 rpm.

The stability of phosphoinositide containing liposomes was investigated. It was found that 2% of triton X-100 completely released entrapped carboxyfluorescein. The release of carboxyfluorescein occurred the most of 58 degrees C (78% at 2 hours) and the least at 4 degrees C (5.4% at 118 hours). When stored at 68 RPM (at 25 degrees C) about the 20% carboxyfluorescein was released at 48 hours, but when the liposomes were kept at 25 degrees C for the same period of time, the release was about 10%.

Journal Article↗

Stability of aminophylline.

The stability of aminophyline was studied in the presence of four tablet excipients (callu1ose starh, glucose and lactose) and nine intravenous fluids (water for injection, dextrose. 10% normal saline, dextrose normal saline 5%, Ringer lactate, Ringer, aminoplasmal 5%, lipofundin 10%, total parenteral nutrition solution TPNS). Ten percent mixtures of the powder drug with the excipients were kept at 5 degrees C, room temperature (27+/-3 degrees C), 45 degrees C and in direct sunlight for 30 days. The degradation of the drug increases with increase in temperature and on exposure to sunlight. The degradation is particularly intense in the presence of glucose and lactose and change in colour from white to yellow occurs in such mixtures. At 45 degrees C and in sunlight both pure drug and its mixtures change colour during the storage period. In intravenous fluids, the drug (1 g/L) is stable and physically compatible for 2 days at 5 degrees C, 27+/-3 degrees C and 45 degrees C except in lipofundin 10% and TPNS where the drug is stable for only 12 hours at 45 degrees C. Yellow tinge appears in the admixtures containing dextrose after 2 days at room temperature and at 45 degrees C.

Journal Article↗

Simple, efficient and simultaneous determination of anabolic steroids in human urine.

A high performance liquid chromatographic method for the determination of free anabolic drug "sustanon 250" (Organon) is developed. Four testosterone esters, propionate, phenylpropionate, isocaproate and decanoate were detected simultaneously and quantitatively in only 15 minutes. The percentage extraction in dichloromethane of the four testosterone esters from doped urine was 88, 87, 89 and 94% respectively. The separation recorded at 254 nm using analytical column ODS-C18 and methanol as an eluent, showed no interference of naturally occurring steroids. This method can be used for pharmacokinetic studies, routine analysis in pharmaceutical industry, routine therapeutic surveillance and in drug abuse by sportsmen.

Anabolic Agents↗

Soil sorption of 20 PCB congeners and six chlorobenzenes.

The soil sorption of six chlorobenzenes and 20 PCB congeners was studied by allowing aqueous trace solutions (ppb) of transformer fluids to equilibrate with 3-6 different soils. Linear relations were found between distribution constants and soil organic carbon content. Sorption was favored by a high degree of chlorination and the absence of ortho-substitution in the biphenyl. Sorption kinetics seemed to be first-order controlled (two steps) with rate constants in the order of many hours. We present correlations between sorption data and published physical data, which will be useful for modeling the transport and the fate of PCBs and chlorobenzenes in the environment.

Adsorption↗

New refractive method for laser thermal keratoplasty with the Co:MgF2 laser.

We have observed corneal curvature changes from laser thermal keratoplasty with a Co:MgF2 laser. We studied corneal curvature changes in rabbits and have identified specific treatment patterns and laser parameters that can correct myopia and astigmatism. These corneal changes, some as large as 8 diopters, have been stable for at least one year, and slitlamp examination demonstrates clear central corneas with normal appearance.

Animals↗

Separation of liposome populations differing in phosphoinositide content by chromatography on immobilized neomycin.

A method is presented by which liposomal populations can be separated based on their content of phosphatidylinositol 4,5-bisphosphate (PIP2). Neomycin is reductively coupled to sepharose 2B and used as the stationary phase in column chromatography. Liposomes of egg lecithin (EL) plus acidic phospholipid containing as little as 10 mol% PIP2 are quantitatively retained in 0.2 M NaCl, while liposomes containing other anionic lipids are recovered to 70-97%. It is possible that lipid redistribution of the bilayers upon contact with the sepharose:neomycin adduct may result in the formatin of multiple populations, and the percent retention by the column for each of the EL:phosphoinositide liposomes would be determined by the new equilibrium established as a result of these interactions. When mixed liposomal populations were chromatographed, the recovery in the 0.2 M NaCl eluates was the sum of the individual recoveries, and there is no significant interchange of lipids between the two liposome populations. It is suggested that this procedure may be useful in the preparation of asymmetric liposomes by facilitating separation of populations devoid of PIP2 in the outer leaflet from unreacted liposomes after enzymatic treatment of symmetric PIP2-containing liposomes.

Chromatography, Gel↗

Complexation of tetracyclines with metal ions in relation to photosensitization.

It has been shown by spectroscopy and by a Photosensitive Index method, involving measurements of interfacial tension, that Cu2+ and Ni2+ form 2:1 complexes with oxytetracycline and 1:1 complexes with demethylchlortetracycline. Fe2+, Zn2+, Mg2+ and Ca2+ form weaker 1:1 complexes with both drugs. The possibility is discussed of using metal ions to reduce photosensitization by tetracyclines in-vivo.

Chemical Phenomena↗