Biomedical subjects

M A Ali

Publications and source records attributed to M A Ali.

At least 19 recordsLinked to original sources

PubMed1992

Fine-needle aspiration biopsy of Ki-1-positive anaplastic large-cell lymphoma.

Five cases of Ki-1-positive anaplastic large-cell lymphoma diagnosed by fine-needle aspiration biopsy are reviewed, and cytologic, histologic, and ultrastructural findings in these cases are correlated. In all cases, the diagnosis of anaplastic large-cell lymphoma was suggested on the basis of the morphological appearance in aspiration smears. This diagnosis was confirmed by immunohistochemistry, which revealed strong positivity of most of the cells by Ki-1 antibody. Two of the lymphomas were T-cell type, one was B-cell type, and the remaining 2 were composed of null cells. In 2 cases, intracytoplasmic inclusions were seen in some of the tumor cells in aspiration smears. These were ultrastructurally correlated with large lysosomal bodies of variable morphology. Fine-needle aspiration combined with immunohistochemistry may be an effective technique for diagnosing this neoplasm.

Adolescent↗

PubMed1992

Fine-needle aspiration biopsy of pediatric neoplasms: correlation between electron microscopy and immunocytochemistry in diagnosis and classification.

A series of fine-needle aspiration biopsies performed in 635 children were reviewed. The diagnoses rendered in these patients included malignant lymphoma in 139 (21.9%); Hodgkin's disease, 25 (3.9%); neuroblastoma, 58 (9.1%); Wilms' Tumor, 37 (5.8%); Ewing's sarcoma, 32 (5.0%); rhabdomyosarcoma, 25 (3.9%); retinoblastoma, 22 (3.5%); leukemia infiltrate, 33 (5.2%); and miscellaneous tumors, 52 (8.2%). In 171 patients (26.9%), the biopsy was nondiagnostic. The cytomorphological characteristics of these lesions are briefly described and illustrated. Salient morphological features are further correlated with histological and ultrastructural appearances. Immunocytochemical patterns of these tumors are also discussed briefly.

Biopsy, Needle↗

PubMed1992

Fine-needle aspiration biopsy diagnosis of rhabdomyosarcoma: cytologic, histologic, and ultrastructural correlations.

A series of 15 cases of rhabdomyosarcoma diagnosed by fine-needle aspiration biopsy (FNAB) and confirmed by histopathology is reviewed. Cytologically, the tumors were composed of a variable mixture of cells, which according to the degree of differentiation were categorized as early, intermediate, or late rhabdomyoblasts. Histologically, the tumors were divided into embryonal 9, monomorphic round cell 4, and alveolar rhabdomyosarcoma 2. Comparison of histological and cytological features revealed that embryonal types were composed mainly of early rhabdomyoblasts. Recognition of these patterns may be helpful in FNAB diagnosis of rhabdomyosarcoma.

Adolescent↗

PubMed1992

Effects of photoperiod and temperature on rhythmic melatonin secretion from the pineal organ of the white sucker (Catostomus commersoni) in vitro.

The secretion rate of melatonin from cultured pineal organs of the white sucker was examined for several days under either a 12:12-hr light:dark (LD) cycle or continuous darkness (DD) at either 10 degrees or 20 degrees. The incubation medium was changed at 3-hr intervals and secreted melatonin was measured by RIA. Under a 12:12-hr LD cycle (0800 light on, 2000 light off) melatonin secretion was suppressed during the day and highly active at night, with larger amplitudes at 20 than at 10 degrees. In DD at 10 degrees no circadian rhythmicity in secretion was found in October or January, whereas at 20 degrees a circadian-like pattern was detected in pineals which were derived from animals reared at either 10 degrees or 20 degrees for 1 week prior to the experiment in October or January. The pineals in the DD experiment still responded to an additional 24-hr LD cycle at both temperatures even after 6 or more days. These results clearly reveal the influence of photoperiod and temperature on melatonin secretion of organ-cultured pineal glands. The existence of a circadian oscillator for melatonin secretion in the pineal gland of the white sucker is suggested.

Animals↗

PubMed1992

Localization of the antigenic sites and intrinsic protein kinase domain within a 300 amino acid segment of the ribonucleotide reductase large subunit from herpes simplex virus type 2.

The 140-kDa ribonucleotide reductase (RR1) protein of herpes simplex virus type 2 (HSV-2) functions as the large subunit of virus-specified RR1 and exhibits an intrinsic protein kinase (PK) activity at its unique NH2-terminal region. The N-terminal half of RR1 contains the protein and DNA functions of the morphological transforming region III (mtrIII) of HSV-2. In the present study, we have expressed a number of truncated RR1 derivatives in a mammalian expression vector containing NH2-terminal RR1 gene fragments and amber mutants generated by site-specific mutagenesis. These derivatives, synthesized in transient expression assays, were used as test antigens to localize the epitopes of a panel of HSV-2 RR1-reactive monoclonal antibodies and to fine-map the PK catalytic domain. Our data show that the epitope for HSV-2-specific monoclonal antibody 6A-6 is located in a region of RR1 protein spanning aa 72-350. The epitopes for cross-reactive antibodies to HSV RR1, i.e., 48S and 51S, are formed predominantly by a stretch of amino acid residues specified by aa 350-376 of the RR1 molecule. The 6A-6 antibody utilized in conjunction with the RR1 amber mutants has allowed us to define a 278 aa domain within the NH2-terminal half of the 140-kDa RR1 (aa 72-350) that is sufficient for PK activity.

Base Sequence↗

PubMed1992

Relations between epidermal growth factor receptor and oestrogen and progesterone receptors in breast cancers of premenopausal and postmenopausal patients in Kuwait.

The levels of cell membrane epidermal growth factor receptor EGFR and cytosol (c) and nuclear (n), oestrogen (E) and progesterone (P) receptors (R) were determined in 132 specimens of primary breast cancers. In the tumours of postmenopausal women an inverse significant correlation was demonstrated between the concentrations of EGFR vs. ERc, ERn, and PRc while no such correlation was noted in the tumours of premenopausal women. Premenopausal and postmenopausal EGFR positive tumours (> or = 10 fmol/mg membrane protein) could be regarded as homogenous with respect to the concentration of ER and PR whose mean values were low and without being significantly different. EGFR negative tumours were heterogeneous with respect to the ER and PR concentrations. Postmenopausal EGFR negative (< 10 fmol/mg membrane protein) tumours had evidently higher mean values of ER and PR than premenopausal EGFR negative tumours, but these differences were statistically significant for oestrogen receptors only. The levels of ER and PR of premenopausal EGFR negative tumours were approximated to the corresponding levels of EGFR positive tumours.

Adult↗

PubMed1992

Comparative ultrastructure and opsin immunocytochemistry of the retina and pineal organ in fish.

The pineal organ and retina were compared in developing charr and cisco, further in adult cisco, eel, creek chub, dace, zebrafish and black moli by opsin immunocytochemistry. In prehatching charr embryos, retinal rods and cones and pinealocytes displayed well-developed outer segments and formed synapses. Differentiation of the retina started centrally but was more advanced in the dorso-caudal retina than rostroventrally. The pineal organ differentiated earlier distally than proximally. In the cisco, the pineal organ and retina differentiated around hatching. In charr embryos, further in the larval and adult species studied, opsin immunoreactivity was found in retinal rods, accessory cones and many "rod-like" pinealocytes, a result indicating the presence of rhodopsin and/or porphyropsin. Retinal principle cones, long and short cones and some "cone-like" pinealocytes were opsin-immunonegative; they are thought to represent red- and/or u.v./violet-sensitive elements. The pineal organ may be involved in negative phototaxic behavior. Both the retina and pineal organ appear to be suitably differentiated to detect light in the larval and embryonic charr.

Animals↗

PubMed1992

Hepatitis C virus infection in chronic haemodialysis patients, a clinicopathologic study.

Fifty-two patients on regular haemodialysis at our institution were evaluated for the presence of HCV infection. Evaluation included detailed history, clinical examination, and monthly screening for anti-HCV antibody, liver enzymes (ALT, AST), serum iron and ferritin. Also, three-monthly screening for other viral markers, HBV (HBsAg, HBsAb, HBcAb), CMV (IgG and IgM), EBV, and HIV. Anti-HCV antibody was found in 21 patients (40.4%). There was a significant (P less than 0.05) relationship between presence of anti-HCV antibody and proportion of patients who received blood transfusion. During a 12-month follow-up, four (11.4%) patients seroconverted to be Anti-HCV positive while one case (4.8%) seroconverted to be anti-HCV negative. The frequency of elevation of liver enzymes was significantly higher in Anti-HCV positive cases (14/18) than in negative cases (11/28, P = 0.01). Evaluation of liver biopsies of 13 patients showed chronic persistent hepatitis in six and chronic active hepatitis in seven cases. We concluded that hepatitis C is a common problem among chronic haemodialysis patients at our institution; HCV infection is documented in 70% of all clinically diagnosed NANB hepatitis. Presence of anti-HCV antibodies cannot differentiate between active and past infection and cases with early HCV infection can be missed when relying on the mere detection of anti-HCV antibodies.

Adult↗

PubMed1992

A prospective study to determine the safety of omitting the antiglobulin crossmatch from pretransfusion testing.

Transfusion medicine laboratories routinely perform a series of pretransfusion serological tests including: ABO grouping, Rh typing, and investigation of the recipient's serum to detect antibodies against blood group antigens (antibody screen). As a final check, most laboratories also perform a crossmatch in which the recipient's serum is incubated with the donor's red cells followed by the addition of an antiglobulin reagent (antiglobulin crossmatch). The need for the antiglobulin crossmatch when the antibody screen is negative has been questioned because there are few antibodies that are detected by this test. Such antibodies are usually directed against low incidence antigens that are not expressed on the screening cells and in many cases the clinical importance of these antibodies is uncertain. For these reasons, we performed a prospective study in which patients requiring red cell transfusion had a group and screen performed. If the antibody screen was negative the antiglobulin crossmatch was omitted. Following the transfusion of the blood, the antiglobulin crossmatch was performed to look for any potential incompatibility. All patients were monitored both serologically and clinically. Over the 2-year interval of the study 9128 patients were entered. There were 8936 patients (97.9%) with a negative antibody screen and 26.9% (2404 patients) were transfused a total of 10,899 red cell concentrates. The antiglobulin crossmatch performed after the transfusion indicated that 168 red cell concentrates (1.5%) would have been incompatible if the antiglobulin crossmatch had been performed pretransfusion. These 168 red cell concentrates were transfused to 119 patients during 130 transfusion episodes (defined as all transfusions administered within 24 h). Of the 130 transfusion episodes, 79.2% (103/130) were false positive laboratory results. There were 27 transfusion episodes where the antiglobulin crossmatch on blood transfused was positive due to an IgG antibody. Even though these transfused red cell concentrates were designated incompatible by the antiglobulin crossmatch, none of the patients receiving this blood had clinical or serological evidence of haemolysis. We concluded that the antiglobulin phase of the crossmatch can be omitted from pretransfusion testing without putting patients at risk.

Blood Component Transfusion↗

PubMed1992

Immunohistochemical study of the development of serotoninergic neurons in the brain of the brook trout Salvelinus fontinalis.

Serotonin is believed to play an important role in the neuronal development of various invertebrates and mammals, but only one study has yet investigated the development of serotoninergic neurons in the brain of a teleost. In the present study, we investigate the development of serotoninergic neurons in the brain of the brook trout, Salvelinus fontinalis, by immunohistochemistry, from fertilisation to the resorption of the yolk sac and in juveniles for reference. Maintaining trout embryos and larvae in 9L:15D or in complete darkness made no difference in the appearance and distribution of serotonin immunoreactive (5-HTir) neurons. On day 56, the first 5-HTir perikarya, indicative of the primordia of the nuclei raphe medialis/dorsalis, have stained in the presumptive isthmus region. At hatching time (days 95-115), all the 5-HTir nuclei reported in the juvenile are present, except for the population observed in the lobus inferior hypothalami. We observed that the nucleus recessus lateralis stained on day 58, the raphe caudal nucleus on day 60, the nuclei raphe pallidus and obscurus on day 65, the area praetectalis on day 80, and the nucleus recessus posterioris and the anterior group of the nucleus recessus lateralis on day 92. At the complete resorption of the yolk sac (days 175-190), the nucleus reticularis paragigantocellularis, the nuclei raphe pallidus and obscurus and the caudal raphe of the brainstem are very weakly immunoreactive, and in juveniles, only one caudal immunoreactive nucleus is still present. A comparison of our result with those previously reported in the three-spined stickleback, Gasterosteus aculeatus, suggest a similar distribution of 5-HTir neurons in the brain of both species but also reveal species differences in the sequence of appearance of 5HT immunoreactivity in the different neuronal populations.

Animals↗

PubMed1992

Effect of n-3 fatty acids from fish oil on hemostasis, blood pressure, and lipid profile of dialysis patients.

Dialysis patients have an inordinate risk of cardiovascular events. Fish oils, rich in n-3 fatty acids, are believed to be beneficial in the prevention of atherosclerosis and thrombosis. Hence, the use of fish oils deserves consideration as a preventative or therapeutic intervention in dialysis patients. The suggestion has been made that n-3 fatty acids could increase the risk of bleeding, and thus, the safety of the use of these agents in dialysis patients must be established before long-term studies are undertaken. This study addresses the effect of n-3 fatty acids on the hemostatic profile of dialysis patients. Sixteen patients on chronic dialysis therapy were randomized to fish oil (MaxEPA) or placebo (olive oil) in a double-blind cross-over study. They received 3.6 g of n-3 fatty acids for 4 wk. Bleeding times were 4.8 +/- 0.4 min on MaxEPA and 4.5 +/- 0.3 min on placebo. Platelet aggregation to low-dose ADP or collagen also remained unchanged. There was a trend to lower serum triglyceride levels (2.7 +/- 0.5 versus 3.4 +/- 0.6 mmol/L, fish oil versus placebo) that did not reach statistical significance. Gastrointestinal side effects occurred in 10 of the 16 subjects and were severe in 5 patients. These side effects occurred in both the olive oil and the fish oil groups. The study had a 95% chance of detecting a clinically doubling significant increase in bleeding time, i.e., beta error less than 5%. In conclusion, n-3 fatty acids do not introduce a clinically important risk of bleeding for patients with end-stage renal disease.

Adult↗

PubMed1992

Histochemical classification of human minor labial salivary glands according to their glycoprotein content.

There is debate about the nature of the secretory cells in human labial salivary glands. Histologically two types of acinar cells were observed. The predominant mucous acini, few basophilic serous acinar cells were detected. Histochemical differentiation of these cells according to their neutral and acidic mucopolysaccharides content using PAS, AB pH 1 and AB pH 2.5 stain revealed the presence of three types of acinar cells: 1. Cells rich in both neutral and acidic mucopolysaccharides. 2. Cells rich in either neutral or acidic mucopolysaccharides. 3. Cells contain neither neutral nor acidic mucopolysaccharides. The first type constitute the major component of the gland.

Glycoproteins↗

PubMed1992

Giant epithelioid leiomyoblastoma of the stomach--a diagnostic dilemma.

Epithelioid leiomyoblastoma (ELB) of the stomach is an uncommon slow growing smooth muscle tumour, attaining enormous size and presenting with bizzare symptoms. We report one such case which posed a diagnostic problem to both the clinician and the radiologist; the condition was diagnosed after laparotomy and histological examination.

Diagnosis, Differential↗

PubMed1992

The protective effect of vitamin E on the hemolysis associated with dapsone treatment in patients with dermatitis herpetiformis.

OBJECTIVE: This study looked at whether oral vitamin C and vitamin E would protect the erythrocyte from oxidant damage caused by dapsone in patients with dermatitis herpetiformis. DESIGN: Fifteen consecutive patients with dermatitis herpetiformis taking dapsone therapy received, in addition, 800 U/d of vitamin E for 4 weeks; then 1000 mg of vitamin C per day for 4 weeks, and, finally, combined vitamin E and vitamin C therapy for 4 weeks. Hemolysis indexes were assessed at baseline and after each 4-week period. RESULTS: Statistical analysis of the results suggests that oral administration of 800 units of vitamin E daily for 4 weeks confers partial protective effect against dapsone-induced hemolysis in patients with dermatitis herpetiformis. CONCLUSION: Partial protection against dapsone-induced hemolysis by orally administered vitamin E, if confirmed as being clinically relevant by further trials, may allow clinicians to continue dapsone therapy orally in patients who develop significant hemolysis. Prophylactic vitamin E to minimize potential hemolysis at the initiation of dapsone therapy may also be appropriate.

Adult↗

PubMed1991

Enhanced malignant transformation induced by expression of a distinct protein domain of ribonucleotide reductase large subunit from herpes simplex virus type 2.

The 1.3-kilobase (kb) Pst I DNA fragment C (Pst I-C) of herpes simplex virus type 2 (HSV-2) morphological transforming region III (mtrIII; map unit 0.562-0.570) encodes part of the N-terminal half of the large subunit of ribonucleotide reductase (RR1; amino acid residues 71-502) and induces the neoplastic transformation of immortalized cell lines. To assess directly the role of these RR1 protein sequences in cell transformation, the Pst I-C fragment was cloned in an expression vector (p91023) containing an adenovirus-simian virus 40 promoter-enhancer to generate recombinant plasmid p9-C. Expression of a protein domain (approximately 65 kDa) was observed in p9-C-transfected COS-7 and Rat2 cells but not in those transfected with plasmid pHC-14 (Pst I-C in a promoterless vector). In Rat2 cells, p9-C induced highly transformed foci at an elevated frequency compared with that of pHC-14. Introduction of translation termination (TAG) condons within the RR1 coding sequence and within all three reading frames inactivated RR1 protein expression from p9-C and reduced its transforming activity to the level seen with the standard pHC-14 construct. Wild-type p9-C specified a protein kinase capable of autophosphorylation. Computer-assisted analysis further revealed significant similarity between regions of mtrIII-specific RR1 and amino acid patterns conserved within the proinsulin precursor family and DNA transposition proteins. These results identify a distinct domain of the HSV-2 RR1 protein involved in the induction of enhanced malignant transformation. In addition, the data indicate that the mtrIII DNA itself can induce basal-level transformation in the absence of protein expression.

Amino Acid Sequence↗

PubMed1991

Thio and epidithio derivatives of methyl beta-lactoside.

Treatment of methyl beta-lactoside with triphenylphosphine-carbon tetrabromide in pyridine gave the 3',6'-anhydro-6-bromo-6-deoxy derivative, from which 6-thio derivatives were prepared, and methyl 3',4'-O-isopropylidene-beta-lactoside gave the 6,6'-dibromo-6,6'-dideoxy derivative. A dibromide was prepared also from methyl 4',6'-O-benzylidene-beta-lactoside by bromination with Ph3P-CBr4, acetylation, and then treatment with N-bromosuccinimide. Various 6,6'-dithio derivatives were prepared from the 6,6'-dibromide by nucleophilic substitution reactions. Reaction of the 6,6'-dibromide with thiourea led to the 6,6'-epidithio derivative and, with potassium tricarbonate, the bridged 6,6'-trithiocarbonate was formed. The 6,6'-dibromo derivative underwent selective nucleophilic substitution to give a variety of 6'-bromo-6-thio derivatives. Likewise, with azide, the 6-azide was formed first, followed by the 6,6'-diazide and the product of elimination, the 6-azido-5%-ene. Raney nickel-mediated desulphuration of the various 6,6'-dithio derivatives afforded methyl 6,6'-dideoxy-beta-lactoside and desulphuration of the 6'-bromo-6-thio derivatives could be accomplished without reductive dehalogenation to give methyl 6'-bromo-6,6'-dideoxylactoside.

Carbohydrate Sequence↗

PubMed1991

Skin fibroblast cell lines derived from non-Hodgkin's-lymphoma (NHL) patients show increased sensitivity to chronic gamma irradiation.

Cultured fibroblast cells from 19 patients with non-Hodgkin's lymphoma (NHL), 3 patients with ataxia telangiectasia (AT), 3 AT heterozygotes and 11 (presumed) normal subjects were studied for impaired colony-forming ability after chronic gamma irradiation. Five cell lines from the NHL patients were also examined for the sensitivity to acute gamma irradiation, as compared with those of normal subjects. To ascertain the degree of radiosensitivity of different cell lines, a comparison was made of the D10 values (radiation dose resulting in 10% survival) for each cell line, estimated "by eye" from the actual survival curves, and also from the calculated curves fitted to a log-linear model. It was observed that the acute gamma irradiation failed to show any appreciable difference in the radiation response of the cell lines from NHL patients as compared with those of normal subjects. However, chronic irradiation demonstrated significantly increased radiosensitivity in at least 10-12 NHL patients with a p value of less than 0.05, when the D10 values of each patient's cell line were compared with the calculated composite values for the normals. When the D10 values of the NHL patients and the normal subjects were compared as 2 groups, the former appeared to be significantly more sensitive to chronic gamma irradiation (p less than 0.0001). The same level of significant difference in radiosensitivity was found between the 2 groups when their D37 values (radiation dose resulting in 37% survival) were compared. In general, the radiation response of the NHL patients was similar to that of the AT homozygotes and heterozygotes used as a positive control group. Our data thus show that increased radiosensitivity is associated with the NHL patients studied, indicating an underlying abnormality of their DNA repair.

Adult↗

PubMed1991

Fine-needle aspiration biopsy diagnosis of malignant rhabdoid tumor of the kidney.

A series of six fine-needle aspiration biopsies from three patients with malignant rhabdoid tumor of the kidney is reviewed. The smears revealed round, polygonal, and irregularly shaped cells with large nuclei and prominent nucleoli. Some of the tumor cells contained light pink to purple cytoplasmic inclusions that correlated with the eosinophilic inclusions seen in histopathologic sections and filamentous cytoplasmic aggregates noted on ultrastructural examination. Diagnosis of malignant rhabdoid tumor of the kidney may be suggested from aspiration biopsy smears; however, further confirmation of the diagnosis by histologic or ultrastructural examination is desirable.

Biopsy, Needle↗