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Biomedical subjects

M A Ali

Publications and source records attributed to M A Ali.

At least 73 records · Page 4Linked to original sources
PubMed1997

Reconstruction of a medial tibial plateau defect using a "pillar" bone graft--a report of two knee reconstructions.

A technique of reconstructing a large tibial plateau defect has been described using a solid bone graft as a pillar to hold up the tibial component of a total knee replacement. The advantage of using a solid bone graft is that there is good initial structural support for the tibial component. This enables early mobilisation. This method has worked well in the two knees reported. Other methods of reconstructing a tibial plateau defect are discussed.

Aged↗
PubMed1996

Recognizing and investigating iron-deficiency anemia in hospitalized elderly people.

OBJECTIVE: To determine whether anemia is documented and appropriately investigated for iron deficiency in hospitalized elderly people. DESIGN: Retrospective chart review. SETTING: Medical clinical teaching unit (CTU) in secondary care hospital in Hamilton, Ont. PARTICIPANTS: Consecutive patients 65 years of age or older admitted between April 1992 and March 1993. OUTCOME MEASURES: Proportion of anemic patients for whom documentation was adequate (included in problem list in patient chart) and for whom adequate investigations were performed (measurement of serum ferritin level in anemic patients in whom iron deficiency was suspected, bone-marrow aspiration for those with intermediate probability of iron deficiency after determination of serum ferritin level, and endoscopy of upper or lower gastrointestinal tract, or both, in patients with iron deficiency). RESULTS: Of 183 eligible patients admitted to the CTU 66 (36%) had anemia, in 47 cases (71%) the anemia was documented by house staff or attending physicians. Of the 66 anemic patients 49 had a non-macrocytic anemia of unknown cause: 26 had their serum ferritin level measured, 5 underwent bone-marrow aspiration, and 21 were referred for gastrointestinal endoscopy. Six of eight patients with probable iron deficiency (i.e., a serum ferritin level that was diagnostic [less than 18 micrograms/L] or suggestive [18 to 45 micrograms/L]) underwent endoscopy, two were found to have cancer of the stomach or cecum. Only 26 of the 49 patients had adequate investigation. CONCLUSIONS: Anemia is common among elderly patients in hospital. However, iron deficiency is underrecognized and underinvestigated.

Aged↗
PubMed1996

Characterization of an essential HSV-1 protein encoded by the UL25 gene reported to be involved in virus penetration and capsid assembly.

The 2.3-kb BamHI-U DNA fragment (map units 0.319-0.335) of herpes simplex virus type 1 (HSV-1) genome contains the complete UL25 open reading frame (ORF). It specifies an essential viral protein reported previously to be involved in virus penetration and capsid assembly (C. Addison, F. J. Rixon, J. W. Palfreyman, M. O'Hara, and V. G. Preston, Virology 138, 246-259, 1984). To identify the protein encoded by the UL25 gene, the UL25 ORF was cloned in a eukaryotic expression vector (p91023) downstream of the adenovirus major late promoter to generate the expression plasmid p9-UL25. Synthesis of a 60-kDa protein was observed in COS-7 cells transfected with p9-UL25 plasmid DNA, but not in cells transfected with p91023 control plasmid DNA. To identify and characterize the UL25 protein from HSV-1-infected cells, we prepared a rabbit antiserum by using UL25-GST fusion protein expressed in Escherichia coli as immunogen. This rabbit antiserum readily immunoprecipitated the 60-kDa UL25 protein from HSV-1-infected cells. In HSV-1-infected cells, UL25 protein was expressed as a late (gamma) or a leaky late (gamma 1) viral protein. The rabbit antiserum raised against HSV-1 UL25 protein immunoprecipitated a UL25-homologue of identical size from HSV-2-infected cells. However, the reactivity of the antiserum with HSV-2 UL25-homologue was weaker than compared to the corresponding HSV-1 protein. Consistent with its classification as a virion component, the UL25 protein was found to be associated with purified HSV-1 virions.

Animals↗
PubMed1996

The onset of NIDDM and its relationship to clinical diagnosis in Egyptian adults.

The onset of diabetes relative to clinical diagnosis was estimated in Egyptians with non-insulin-dependent diabetes mellitus (NIDDM) based on the relationship between retinopathy and duration of diabetes. Between July 1992 and October 1993 the Diabetes in Egypt (DIE) Project performed a cross-sectional, population-based survey with clinical and laboratory follow-up to describe the prevalence of microvascular, neuropathic, and macrovascular complications among Egyptians > or = 20 years of age with diagnosed diabetes, previously undiagnosed diabetes, impaired glucose tolerance, and normal glucose tolerance. The sample of persons with diabetes diagnosed prior to the survey had medical examinations which included a dilated eye examination and retinal photographs. Generalized linear models were used to relate the probability of retinopathy to duration of diabetes. Among 218 persons with diabetes diagnosed prior to the DIE project, 87 (40%) had diabetic retinopathy. The onset of retinopathy was estimated to occur 2.6 years (p = 0.04) prior to clinical diagnosis. The estimated annual incidence of retinopathy was 5% and the estimated prevalence at the time of clinical diagnosis of diabetes was 12%. On the basis of reports that retinopathy does not occur until approximately 5 years after the development of diabetes, the onset of NIDDM was estimated to occur 7.6 years prior to its clinical diagnosis. This estimate of the onset of NIDDM in Egyptians is comparable to other estimates reported for US and Australian populations.

Adult↗
PubMed1996

Rhythmic melatonin secretion in different teleost species: an in vitro study.

The rhythmic production of melatonin is governed by intrapineal oscillators in all fish species so far investigated except the rainbow trout. To determine whether the latter represents an exception among fish, we measured in vitro melatonin secretion in pineal organs of nine wild freshwater and six marine teleost species cultured at constant temperature and under different photic conditions. The results demonstrate that pineal organs of all species maintain a rhythmic secretion of melatonin under light:dark cycles and complete darkness, and strongly suggest that most fish possess endogenous intrapineal oscillators driving the rhythm of melatonin production, with the exception of the rainbow trout.

Animals↗
PubMed1996

Deletion of the carboxy-terminus of herpes simplex virus type 1 (HSV-1) glycoprotein B does not affect oligomerization, heparin-binding activity, or its ability to protect against HSV challenge.

A recombinant vaccinia virus designated VgBt which expresses a truncated secreted herpes simplex virus gB (gBt) was constructed and compared to V11gB, a vaccinia recombinant previously studied which expresses gB exclusively on the surface of infected cells. Indirect immunofluorescence assay (IFA) revealed that gBt was strongly associated with the surface of infected cells despite being released slowly into the cell culture medium. Both gB and gBt existed as oligomers, and both membrane bound and secreted forms of gBt exhibited heparin-binding activity. In protection studies VgBt and V11gB conferred equivalent protection against both homologous (HSV-1) and heterologous (HSV-2) challenge with HSV.

Animals↗
PubMed1996

Cytogenetic findings in renal cell carcinoma.

Cytogenetic characterization of 24 renal cell carcinomas (RCCs) was performed. The various RCC subtypes included 8 chromophobe RCCs, 12 nonpapillary RCCs, and 4 papillary RCCs. Loss of chromosomes 1, 2, 6, 10, and 17 were observed in 5 of 8 chromophobe RCCs. Five of the 12 nonpapillary RCCs showed abnormalities involving chromosome 3. These were deletion of the 3p13 region, loss of the whole chromosome 3, and unbalanced translocation resulting in a derivative. Of the 4 papillary RCCs, two showed trisomy 7 and 17 along with other abnormalities, one had trisomy for chromosomes 7, 12, and 13, along with loss of chromosome #5 and Y chromosomes, and another papillary RCC revealed trisomy 15 and trisomy 17. These results further show that specific cytogenetic abnormalities are associated with various subtypes of RCCs.

Adult↗
PubMed1996

The evaluation of various mathematical RBC indices and their efficacy in discriminating between thalassemic and non-thalassemic microcytosis.

The differentiation between thalassemic and non-thalassemic microcytosis has important clinical implications in hematology and medicine. A simplified index, based on red cell parameters derived from automated blood cell analyzers, which could be used to discriminate between microcytic patients with a high probability of thalassemia minor and those with a low probability, would be an extremely useful tool. Five mathematical indices have been proposed as useful for this purpose. These are the: Bessman index, Shine and Lal index, England index, Mentzler index, and mean cell volume (MCV) alone. This study was designed to prospectively evaluate the efficacy of these indices. Patient samples were chosen every fourth day from all patient samples referred to the hematology laboratory at St. Joseph's Hospital over a 6-month period. All patient samples with an MCV < 80 fL and age > or = 18 years were considered eligible for the study. After enrollment and laboratory analysis were complete sensitivities and specificities were calculated for each of the indices using a variety of cut-off values and receiver operator characteristic (ROC) curves were constructed. Based on statistical analysis of the area under these curves, the authors conclude that MCV alone is as effective as the Mentzler and Shine and Lal indices in selecting microcytic patient samples with a high probability of thalassemia minor for thalassemia testing. They also conclude that the Bessman index and the England index are ineffective indices for this purpose.

Adult↗
PubMed1996

Papillary thyroid cancer in Saudi Arabia. Clinical, pathologic, and management characteristics.

During a 3-year period, 233 patients with papillary thyroid cancer were seen at King Faisal Specialist Hospital (KFSH) (79% were female; 94% were national subjects). Pathology revealed 88% pure papillary carcinoma and 12% mixed papillary and follicular carcinoma, 7% microfocus, 18% well encapsulated, 24% capsular invasion, and 51% soft tissue invasion. Thirty percent of patients who had initial surgery not done at KFSH compared with 93% of patients who had initial surgery done at KFSH had an I-123 24-hour uptake < 5%. One hundred seventeen patients required completion thyroidectomy at KFSH for significant residual thyroid tissue, 56% of those had residual papillary carcinoma. The amenability of papillary thyroid cancer for cure necessitates the optimization of management at the national level. In Saudi Arabia, papillary thyroid cancer presented in an advanced stage, especially in males as manifested by the large primary tumor size, advance pathologic staging, and distant metastases at the time of presentation. Findings at second surgery, showed significant residual disease.

Adult↗
PubMed1996

Effect of adherent Lactobacillus spp. on in vitro adherence of salmonellae to the intestinal epithelial cells of chicken.

Single strains of Lactobacillus acidophilus and Lact. fermentum, isolated from chicken intestine, were used to study in vitro interactions with Salmonella enteritidis, Salm. pullorum or Salm. typhimurium in an ileal epithelial cell (IEC) radioactive assay. Exclusion, competition and displacement phenomena were investigated by respectively incubating (a) lactobacilli and IEC together, prior to addition of salmonellae, (b) lactobacilli, IEC and salmonellae together, and (c) salmonellae and IEC, followed by the lactobacilli. Lactobacilli were selected for study because of their strong ability to adhere to IEC and poor aggregation with salmonellae. The results demonstrated that Lact. acidophilus significantly reduced (P < 0.05) the attachment of Salm. pullorum to IEC in the tests for exclusion and competition, but not in the displacement tests. Lactobacillus fermentum was found to have some ability to reduce the attachment of Salm. typhimurium to IEC under the conditions of exclusion (P < 0.08), competition (P < 0.09), but not displacement. However, both Lact. acidophilus and Lact. fermentum were unable to reduce the adherence of Salm. enteritidis to IEC under any of the conditions.

Animals↗
PubMed1996

Antagonistic effects of intestinal Lactobacillus isolates on pathogens of chicken.

Twelve Lactobacillus strains isolated from chicken intestine, which demonstrated a strong and moderate capacity to adhere to the ileal epithelial cells in vitro, were used to investigate their inhibitory ability against five strains of salmonella, i.e. Salmonella enteritidis 935/79, Salm. pullorum, Salm. typhimurium, Salm. blockley and Salm. enteritidis 94/448, and three serotypes of Escherichia coli, viz. E. coli O1:K1, O2:K1 and O78:K80. The results showed that all the 12 Lactobacillus isolates were able to inhibit the growth of the five strains of salmonella, and the three strains of E. coli in varying degrees. Generally, they were more effective in inhibiting the growth of salmonella than E. coli. Inhibition of the pathogenic bacteria was probably due to the production of organic acids by the Lactobacillus isolates.

Animals↗
PubMed1996

Adhesion of Lactobacillus isolates to intestinal epithelial cells of chicken.

A total of 46 Lactobacillus isolates obtained from chicken intestine were assessed on their ability to adhere to the chicken ileal epithelial cell (IEC) in vitro. Twelve out of the 46 isolates showed moderate to good ability to adhere to the IEC. Temperature (between 4 degrees C and 42 degrees C) did not affect attachment. Incubation (contact) time of 30 min was found to be insufficient for the attachment of bacteria to the IEC, but contact time beyond 1 h did not increase this ability. The pH values (4-7) of the suspending buffer did not have any significant effect on the attachment of bacteria to the IEC, but at pH 8 it was reduced significantly (P < 0.05).

Animals↗
PubMed1996

Fine structure of the retina and pigment epithelium in the creek chub, Semotilus atromaculatus (Cyprinidae, Teleostei).

The structure of the light- and dark-adapted retina, the pigment epithelium and the choroid of the creek chub, Semotilus atromaculatus (Cyprinidae, Teleostei) is examined by light and electron microscopy. An extensive network of vitreal blood vessels emanating from the hyaloid artery enters the eye with the optic nerve and overlies the inner limiting membrane. This membrane closely apposes the fine protrusions of the Müller cell processes which traverse the entire retina, dividing the inner retina into alternating fascicles of ganglion cells and optic axons. The inner nuclear layer consists of bipolar, amacrine, Müller cell soma and two layers of horizontal cells. The outer plexiform layer possesses both rod spherules and cone pedicles. Each rod spherule consists of a single synaptic ribbon in either a triad or quadrad junctional arrangement within the invaginating terminal endings of the bipolar and horizontal cell processes. In contrast, cone pedicles possess multiple synaptic ribbons within their junctional complexes and, in the light-adapted state, the horizontal cell processes show spinule formation. Four photoreceptor types are identified on morphological criteria; unequal double cones, large single cones, small single cones and rods. All but the small single cones are capable of retinomotor responses. The rod to cone ratio is approximately 5:1 and the rods form two ill-defined rows in the light-adapted condition. The retinal pigment epithelium possesses two types of osmiophilic granules. These are bound within slender microvilli and migrate vitread to surround the photoreceptors in response to light. Bruch's membrane is trilaminar and the vascularised choroid consists of up to three layers of melanocytes. The endothelial borders of the choroidal blood vessels abutting the outer lamina of Bruch's membrane are fenestrated.

Adaptation, Ocular↗
PubMed1996

Ultrastructure and organisation of the retina and pigment epithelium in the cutlips minnow, Exoglossum maxillingua (Cyprinidae, Teleostei).

The structure of the light- and dark-adapted retina, pigment epithelium and choriocapillaris of the cutlips minnow, Exoglossum maxillingua (Cyprinidae, Teleostei) is examined by light and electron microscopy. A pronounced vitreal vascularisation overlies the inner retina where the blood vessel walls, the inner limiting membrane and the Müller cell endfeet are all closely apposed. The thick Müller cell processes divide the inner plexiform layer and nerve fibre layer into discrete compartments. The ganglion cells do not form fascicles and lie within both the ganglion cell and inner plexiform layers. The inner nuclear layer consists of amacrine, bipolar, Müller cell somata and two rows of horizontal cells. The photoreceptor terminals comprise either multiple (3-5 in cone pedicles) or single (rod spherules) synaptic ribbons. These photoreceptor terminals form either a triad (rods and cones) or a quadrad (cones) arrangement of contact with the invaginating processes of the inner nuclear layer cells. The horizontal cell processes of the cone photoreceptor terminals reveal spinule formation in the light-adapted condition. Five photoreceptor types are classified using morphological criteria; triple cones, unequal double cones, large single cones, small single cones and rods. The ratio of rods to cones is approximately 7:1. All photoreceptor types show retinomotor responses. Only the cones possess accessory outer segments but both rods (8-11) and cones (15-19) possess calycal processes. The retinal pigment epithelium displays retinomotor responses where pigment granules within fine apical processes move vitread to mask the rods in the light. The cells of the retinal pigment epithelium are joined by various types of junctions and contain numerous phagosomes, mitochondria and polysomes. Bruch's membrane or the complexus basalis is trilaminate with two types of collagen fibrils comprising the central layer. The endothelia of the blood vessels of the choriocapillaris, facing Bruch's membrane, are fenestrated. Two to three layers of melanocytes interspersed between large thin-walled capillaries and several layers of collagen fibrils comprise the choriocapillaris.

Adaptation, Ocular↗
PubMed1995

The 140-kDa RR1 protein from both HSV-1 and HSV-2 contains an intrinsic protein kinase activity capable of autophosphorylation but it is transphosphorylation defective.

The 140-kDa RR1 protein from both herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) functions as the large subunit of viral ribonucleotide reductase (RR) and contains an intrinsic serine/threonine protein kinase (PK) activity at the unique NH2-terminal domain. This PK activity is capable of autophosphorylation and reported to transphosphorylate histone and calmodulin by some groups but not by others. It has been suggested that the lack of consensus in the finding of transphosphorylation activity with RR1 protein may be due to HSV strain variations used in different laboratories. In the present study, we have attempted to resolve this issue by immunospecifically isolating the 140-kDa RR1 protein from four different strains of HSV-1 including F, KOS, HF, and MP and three different strains of HSV-2 including G, 333, and MS and subjecting them to immunocomplex kinase assays. In PK assays autophosphorylation of 140-kDa RR1 was readily observed in protein immunopurified from all HSV-1 and HSV-2 strains used in this study. However, using the same assay no transphosphorylation activity was observed with either the 38-kDa RR2 protein present in immunocomplex along with the RR1, or with histone, when added as an exogenous PK substrate. This conclusion is further supported by the evidence that a commercial preparation of PK (protein kinase catalytic subunit from bovine heart) readily phosphorylated histone under the conditions used for RR1 immunocomplex kinase assay. These results show that the 140-kDa RR1 protein contains an autokinase activity but it is incapable of transphosphorylating heterologous substrates such as histone. In addition, we show that the RR enzyme complex (140 and 38-kDa proteins) is associated with purified HSV-2 virions.

Adenine Nucleotides↗
PubMed1995

Aspiration cytology of chromophobe cell carcinoma of the kidney.

Fine-needle aspiration biopsy findings in three cases of chromophobe cell carcinoma are described and correlated with histologic and ultrastructural observations. In addition, comparisons are made with three cases each of oncocytoma and granular cell carcinoma. The cells in aspiration smears from chromophobe cell carcinoma closely correlated with histologic pattern of three cell types which were not present in oncocytomas and granular cell carcinomas. These cells had prominent cell borders, and their cytoplasm was either opaque and granular (type I) or variably translucent and reticular (type II and III). Ultrastructurally, the translucent areas within the cytoplasm contained large numbers of microvesicles which were unique to chromophobe cell carcinoma and were not seen in other neoplasms. Fine-needle aspiration may be used to diagnose chromophobe cell carcinoma and distinguish it from other related renal neoplasms.

Adenocarcinoma↗