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Biomedical subjects

M A Ali

Publications and source records attributed to M A Ali.

At least 235 records · Page 13Linked to original sources
PubMed1979

Laboratory diagnosis of HB CC-alpha-thalassemia.

Routine laboratory investigations of hemoglobinopathies include Hb electrophoresis for abnormal hemoglobins, determination of Hb A2 (alpha 2 delta 2) for beta-thalassemia traits, staining for Hb H (beta 4) inclusions for alpha-thalassemia traits and estimation of Hb F (alpha 2 lambda 2) for the presence of hereditary persistence of fetal hemoglobin genes (HPFH). Frequently, analytical column chromatography and alpha/beta hemoglobin chain synthesis are used in the studies of more complicated hemoglobinopathies. This communication outlines the procedures used in this laboratory for the diagnosis of a case of Hb CC-alpha-thalassemia.

Adult↗
PubMed1979

Myotube formation in skeletal muscle regeneration.

Muscle fibre regeneration in the latissimus dorsi of adult rats has been studied by light and electron microscopy. Both 'continuous' and 'discontinuous' modes of regeneration occur. In 'continuous' regeneration sarcoplasmic buds grow from the damaged muscle fibres, their nuclei apparently originating from the healthy portion of the muscle fibre. In 'discontinuous' regeneration mononucleated cells accumulate inside intact but vacated, sarcolemmal tubes. They differentiate into myofibril-containing myoblasts which later fuse. 'Continuous' regeneration occurs when the sarcolemmal sheaths are disrupted; 'discontinuous' regeneration when the sarcolemmal sheaths remain intact.

Animals↗
PubMed1979

The effects of hypophysectomy on the retinomotor responses of the killifish, Fundulus heteroclitus.

This paper presents the results of an investigation concerned with the effects of long-term hypophysectomy on the retinomotor responses of the euryhaline killifish, Fundulus heteroclitus: 1. The eye of hypophysectomised Fundulus heteroclitus responds to light and dark in the same manner as that of intact controls: the retina is not in a state of permanent light-adaptation as claimed by Vilter (1942) for the hypophysectomised eel. 2. There is no evidence of a persistent circadian rhythm during continous darkness. 3. Unilateral illumination of the eye of intact fish results in dispersion of retinal pigment in both illuminated and unilluminated eyes, as in the goldfish (Ali, 1964), but no such contralateral response was evident after hypophysectomy. The cones are unresponsive.

Adaptation, Physiological↗
PubMed1978

Oral hydration rotavirus diarrhoea: a double blind comparison of sucrose with glucose electrolyte solution.

Of 57 male children, aged 5 months to 2 1/2 years with rotavirus diarrhoea, 28 were given oral therapy with sucrose electrolyte solution and 29 were given glucose electrolyte solution in a randomised double-blind trial. All were rehydrated and remained so on oral therapy alone. These patients were compared with 44 children, also with rotavirus, who were treated only with intravenous hydration. The oral therapy and intravenous therapy groups did not differ clinically in the rate of rehydration or the rate of purging. Vomiting did not prevent the giving of oral therapy during hospital admission. Bangladeshi children with rotavirus diarrhoea have a defect of carbohydrate digestion but this defect does not prevent the use of a sugar electrolyte solution for oral hydration.

Administration, Oral↗
PubMed1978

Preleukaemia and reticulocytosis: a case report with in vitro evidence for abnormal reticulocyte maturation.

A case of preleukaemia with marked reticulocytosis and a slightly reduced red cell 51Cr survival is presented. An in vitro 'reticulocyte survival' test suggested that the apparent reticulocytosis was due to delayed maturation of reticulocytes. The globin synthesis ratio suggested an abnormal ribonucleic acid. At autopsy, in addition to the findings of acute leukaemia, mesenteric lipodystrophy was discovered. This abnormality has been seen in patients with malignant diseases, especially lymphomas, but heretofore has not been reported in acute leukaemia.

Erythrocyte Aging↗
PubMed1978

Hemolytic anemia in patients receiving sulfasalazine.

Hemolytic anemia is a well-recognized complication of sulfasalazine treatment. 17 of 40 (43%) patients with inflammatory bowel disease receiving sulfasalazine had evidence of hemolysis as detected by starch gel electrophoresis. Only 47% (8) of patients with hemolysis had Heinz body formation. The hemoglobin was significantly reduced in patients with hemolysis and 53% had a reticulocyte count of greater than 5%. A significant correlation was noted between hemolysis and serum sulfapyridine level, but no correlation was seen with serum sulfasalazine level. There was no significant difference in disease extent or activity in patients with hemolysis compared to those without hemolysis. Hemolysis is not a rare side-effect of sulfasalazine therapy. Heinz body formation is not invariably found in sulfasalazine-induced hemolysis.

Anemia, Hemolytic↗
PubMed1978

Retinal organisation in goldeye and mooneye (Teleostei: hiodontidae).

This paper presents the results of a comparative investigation of the retinas of two Hiodontids, the goldeye (Hiodon alosoides) and the Mooneye (H. tergisus) employing light and electron microscopy, cell isolation techniques as well as microspectrophotometry. Contrary to the observations of previous workers these species possess a duplex retina. The photoreceptors are bundled in groups of 20 rods and 20 cones. They exhibit features which have hitherto not been observed in vertebrates. These are a) an ellipsoid divided in two parts by the myoid: b) tubules in cone outer segments and, c) large "lateral sacs" (accessory outer segments). Cones are immobile but the rods and epithelial pigment are capable of movement (retinomotor responses). The prominent reflecting layer consists of cuboid and rod-like crystals composed of uric acid. The inner layers are made up of three tiers of large horizontal cells, one of amacrine cells and scarce bipolar and ganglion cells. Bundle density is 1 700 per sq. mm. Roughly, one receptor bundle projects onto one bipolar and one ganglion cell suggesting that each bundle acts as a functional unit. The visual pigment of the mooneye absorbs maximally at 535 +/- 2 nm, and is based on vitamin A2 (porphyropsin). We suggest that all non deep-sea fishes with bundled receptors have duplex retinas and the adaptive mechanisms for vision in turbid waters are based on different morphological means as illustrated by the comparison with Stizostedion.

Adaptation, Ocular↗
PubMed1978

[Scotopic visual pigments in 3 Percidae: Perca flavescens, Stizostedion vitreum and S. canadense].

The scotopic visual pigments of three percids from Quebec waters, viz. the yellow perch (Perca flavescens), the walleye (Stizostedion vitreum) and the sauger (S. canadense), were studied in situ using a microspectrophotometer-computer complex. The difference spectra show that the three fishes possess a porphyropsin whose lambda max. is at 530 nm in the yellow perch, 533 nm in the walleye and at 536 in the sauger. This variation corresponds to the tendency of the visual pigments to fit the preferred environments. The three species studied also have different modes of life. The yellow perch inhabits mostly shallow, clear waters while the walleye and sauger prefer turbid waters. The retinal structure and responses also differ among them. Since the difference in lambda max. is so small, the differences in habitat and behaviour may be attributed to morphological differences in the retina rather than to its visual pigment content.

Adaptation, Biological↗
PubMed1978

Microspectrophotometric studies on the visual pigment in the intact retina of the goldfish, Carassius auratus (Linn.).

The visual pigments in intact retinas of the common goldfish were examined by microspectrophotometry. Difference spectra free of photoproduct contamination had absorbance maxima at lambda527 nm +/- 2 nm. The average pigment density, about 0.32, was almost invariant with regard to retinal location and specimen size. Traces of a photoproduct absorbing maximally at lambda480-490 nm were found. The normalized "absorbance" curve deviated from standard templates. It was suggested that this was an effect of cross-coupling of energy and among photoreceptors. Finally, known action spectra show a red shift relative to the absorbance spectra measured.

Animals↗
PubMed1978

Photoreceptors and visual pigments in a cichlid fish, Nannacara anomala.

Correlation of visual pigment content and photoreceptor cell structure is studied in the cichlid fish Nannacara anomala the retina of which is characterized by simple organization of the outer plexiform layer. The visual cell types consist of long and bulky rods and only two types of cones: equal double cones and short single cones. Both types of cones differ form other known teleost cones in that their outer segments are very slender yet twice as long as the inner segments. The double cones form a square mosaic with four doubles along the sides an a single cone in the center. Four rods usually surround the single cone and a few others lie in the corners of the square. The population densities of photoreceptor cells in the central part of the retina is 45,600 cones and 52,600 rods per mm2. The cone to rod ratio is 1:1.15; the double cone to single cone ratio is 4.07:1. The outer segments of photoreceptors contain four spectroscopic types of pigment: one type in rods with lambda max = 498 +/- 5 nm, one type in single cones with lambda max = 460 +/- 5nm, and one in each member of the double cones with lambda max of 555 +/- 5 and 600 +/- 10 nm. Single cones are found to contain only the blue-absorbing pigment. The double cones, whenever both members are successfully recorded from, appear to use two spectrally different pigments. Based on spectral bandwidth determination, the four pigments are probably of the prophyropsin class, although some admixture (10--20%) of rhodopsin-class pigments is also indicated, especially in double cones.

Animals↗
PubMed1977

Megaloblastic anemia in patients receiving total parenteral nutrition without folic acid or vitamin B12 supplementation.

Pancytopenia developed in four patients receiving postoperatively total parenteral nutrition (TPN). Symptoms and signs were related mainly to underlying bowel disease. Hematologic abnormalities, first noted from 4 to 7 weeks following institution of TPN, consisted of normocytic anemia (mean decrease in hemoglobin value, 2.2 g/dL), occasional macrocytes being noted, leukopenia (range of leukocyte counts, 1.2 to 3.6 X 10(9) L), some hypersegmented neutrophils being detected, and clinically significant thrombocytopenia (range of platelet counts, 25 to 52 X 10(9)/L). In all patients the bone marrow showed megaloblastic changes, with ring sideroblasts, although pyridoxine was included in the TPN regimens. Serum vitamin B12 values were normal in one patient and at the lower limit of normal in the other two patients in whom it was measured, while serum or erythrocyte folate values, or both, were reduced in three patients. Full hematologic response was observed in the four patients after folic acid replacement therapy; leukocytosis and thrombocytosis were noted in three. Thus, folic acid and possibly vitamin B12 should be added routinely to TPN regimens to prevent deficiency of either substance.

Anemia, Macrocytic↗
PubMed1977

"Blood and guts": one component of an integrated program in biologic sciences as applied to medicine.

The 3-year medical school program at McMaster University encourages an approach to learning a physician can apply throughout his or her career. The program has four phases and provides early exposure to relevant clinical material. In phase 3, the basic science phase, the structure and function of organ systems in health and disease are studied. Understanding the mechanisms of disease in order to be able to relate clinical symptoms and signs to physiologic and pathologic processes is emphasized. The four 10-week units deal with groups of organ systems. The "blood and guts" unit teaches the student hematology and gastroenterology through a variety of problem-based methods. Specialists in the relevant scientific disciplines influence selection and construction of the problems presented. The students are evaluated by the faculty tutor on their accomplishment of specific objectives related to their competence in solving biomedical problems.

Curriculum↗