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Biomedical subjects

I Hassan

Publications and source records attributed to I Hassan.

At least 55 records · Page 3Linked to original sources
PubMed1997

Selective migration of highly differentiated primed T cells, defined by low expression of CD45RB, across human umbilical vein endothelial cells: effects of viral infection on transmigration.

Low expression of CD45RB on CD45RO+ T lymphocytes defines a subset of highly differentiated T lymphocytes that accumulate in vivo within the affected joints of patients with rheumatoid arthritis (RA). Although it is known that CD45RO+ T lymphocytes migrate to sites of inflammation in vivo, it is not clear whether within this subset the CD45RBlo cells are selectively recruited or develop in situ within the joint. Using a transwell system we show that a small proportion of resting T lymphocytes migrated across unactivated human umbilical vein endothelial cells (HUVEC). These migrating cells were CD45RO+ and enriched for low CD45RB expression. In addition, both the CD45RO+CD45RBlo subset and migrating cells expressed increased levels of beta 1 and beta 2 integrins and CD44. The percentage of CD45RO+CD45RBlo T lymphocytes was increased in the circulation of patients with acute Epstein-Barr virus (EBV) infection. These in vivo activated cells also expressed increased levels beta 1 and beta 2 integrins and CD44, and showed an enhanced rate of transmigration compared with resting T lymphocytes. Transmigration of T lymphocytes was increased using the chemokines RANTES and lymphotactin and the cytokine interleukin-15 (IL-15). In addition, infection of the HUVEC with cytomegalovirus (CMV) led to an enhanced movement of T lymphocytes. In all of these cases the selective migration of the CD45RBlo subset was maintained. Thus although the rate of T-lymphocyte transmigration could be influenced by a number factors, the CD45RO+CD45RBlo subset has a migratory advantage suggesting that more differentiated CD45RO+CD45RBlo T lymphocytes are selectively recruited to sites of inflammation.

Cell Line↗
PubMed1997

Clinical and serological responses to an inactivated influenza vaccine in adults with HIV infection, diabetes, obstructive airways disease, elderly adults and healthy volunteers.

To investigate the clinical and serological responses to an inactivated influenza vaccine (split-virion A/Singapore/6/86-like strains H1N1 (15 ug HA), A/Beijing/353/89-like H3N2 (15 ug HA) and B/Yamagata/16/88-like strain (15 ug HA): MFV-JECT, Merieux, UK) in persons with HIV infection, diabetes, obstructive lung diseases, elderly adults and healthy volunteers. Forty-nine HIV-infected persons received 2 doses of the vaccine at one-month intervals; 34 healthy volunteers, 30 elderly persons, 29 with insulin and non-insulin diabetes and 14 with obstructive airways diseases were vaccinated with one single dose between October 1992 to January 1993. Serological testing of antibody responses was done using haemagglutination assay. Beta2-microglobulin in HIV-infected persons was measured using radioimmunodiffusion between 1st and 2nd dose. Fructosamine levels in diabetic persons were assessed for diabetic control and peak expiratory flow rate (PEFR) was self monitored in persons with lung diseases. All groups apart from the elderly filled in a symptom score chart for the first 5 days following vaccination. A 4-fold rise in titre equal to or more than 1:64 to all the 3 antigens occurred in 20 (58.8%) of healthy volunteers compared with 13 (44.8%) diabetics, 5 (35.7%) with lung diseases, 10 (33.3%) elderly and 13 (26.5%) with HIV infection. A significant correlation of serological response to number of CD4 count in persons with HIV infection was noted (H1N1 P=0.0013, H3N2 P=0.025, BYAM P=0.0018). Mean beta2-microglobulin levels did not change significantly post 1st and 2nd vaccination. Mean fructosamine level did not change significantly. There was no significant change in PEFR. The vaccine was well tolerated. Persons with HIV infection and low CD4 count do not serologically respond well to influenza vaccine even with 2 doses compared to the other 4 groups. The other 4 groups had adequate protective serologic responses. The vaccine was well tolerated in all groups.

Adult↗
PubMed1997

Profile and risk factors for congenital heart disease.

Congenital heart disease is an important cause of infant mortality and disability. The frequency, spectrum and contributory risk factors for significant cardiovascular malformations among live-births was retrospectively evaluated at the Aga Khan University Hospital. Of a total of 8331 live births between July, 1987 and December, 1992 34 babies were diagnosed to have congenital heart disease in the neonatal period giving a prevalence of 4 per 1000 live births. Ventricular septal defects was the most common (n = 10, 29%) abnormality. Eight cases had associated chromosomal abnormality, the most common being Trisomy 21. Maternal abortions, still-births, consanguinity and diabetes mellitus were not found to be significant risk factors for congenital heart disease in this survey.

Case-Control Studies↗
PubMed1997

Road traffic injuries in Karachi: the disproportionate role of buses and trucks.

Road traffic accidents result in substantial injury and death in Karachi. We reviewed the patient logs of the two largest government hospitals in Karachi between December 1993 and February 1994 to identify those persons most likely to be injured in a road traffic accident and to identify the vehicle types which were most likely to be involved. 86% of 727 road injury victims were male. Their mean age was 31 years. One hundred of thirty-one (18%) died. Pedestrians and motorcyclists were the most common victims accounting for 46% all injuries and 51% of deaths. Although buses and trucks were less than 4% of the registered vehicles in Karachi they were the striking vehicle among 49% of all injuries and 65% of the deaths. Road traffic accidents disproportionately affect wage earners. Specific interventions to improve the road safety of trucks and buses are needed.

Accidents, Traffic↗
PubMed1996

Factors that influence activated CD8+ T-cell apoptosis in patients with acute herpesvirus infections: loss of costimulatory molecules CD28, CD5 and CD6 but relative maintenance of Bax and Bcl-X expression.

The expanded CD8+ T-lymphocyte population arising in response to viral infection controls the virus but could also prove damaging to the host unless safely removed at the end of the immune response. Apoptosis provides a mechanism whereby this can be achieved, as apoptotic cells are recognized and engulfed by macrophages. Peripheral blood CD8+ T lymphocytes from individuals with acute viral infections were highly susceptible to apoptosis after short-term culture in vitro. This spontaneous cell death could be prevented by interleukin-2 (IL-2) and was related to a decreased expression of Bcl-2 but not Bax or Bcl-XL, additional molecules that promote or prevent apoptosis, respectively, as well as an increase in CD95. After stimulation with anti-CD3 antibody, T cells from these patients also underwent an activation-induced cell death (AICD) that could not be prevented by IL-2. Interestingly, CD8+ T cells from this patient group expressed lower than normal levels of three costimulatory molecules, CD28, CD5 and CD6, suggesting that stimulation in the absence of a second signal is a possible mechanism for the defective reactivation of these cells. Thus multiple mechanisms, including loss of Bcl-2, increased CD95 and loss of costimulatory molecules, place constraints on the survival and reactivation of activated CD8+ T cells after viral infections. This enables immune activation to be controlled and cellular homeostasis to be re-established during resolution of viral diseases in vivo.

Acute Disease↗
PubMed1995

Cancer of the male breast in Zaria, Nigeria.

Sixteen Nigerian men presented with advanced breast cancer to Ahmadu Bello University Hospital in Zaria, Nigeria over the 15-year period 1975 to 1989. This comprised 9% of patients with breast cancer seen during this period. They had a median age of 55 years, median symptom duration of 12 months and median tumour size of 8cm; 14 (87.5%) of the patients had Stage IV cancer at presentation. Anaplastic and infiltrating ductal carcinomas accounted for 25% and 56.3% respectively, of the tumour histological type. Mastectomy was the mainstay treatment modality. Only 4 patients came for follow-up, for a median duration of 8.5 months. Overall, this pattern is very similar to the pattern of breast cancer in Nigerian women.

Adult↗
PubMed1995

Breast cancer during pregnancy and lactation in Zaria, Nigeria.

As most African women with breast cancer are premenopausal, the probability of pregnancy and lactation co-existing with breast cancer is higher than among the Caucasian patients who are usually post-menopausal. However, because of the relative rarity of breast cancer in black women compared with the Caucasians, experience with gestational breast cancer in African women is very limited. Among 95 women younger than 50 years of age who had the diagnosis of breast cancer over a 12 1/2 year period in Zaria, 25 (26.3%) were either pregnant (n = 14) or lactating (n = 11) at the time of presentation. Comparison of the clinical feature of these 25 with those of the remaining 70 who were neither pregnant nor lactating showed no difference in the clinical presentation, histological tumour type, and the advanced stages of the breast cancer at presentation between the two groups.

Adult↗
PubMed1994

The transport of two iron chelators, desferrioxamine B and L1, across Caco-2 monolayers.

The transport of two iron chelators, desferrioxamine B (DFO) and L1 (1,2-dimethyl-3 hydroxypyridin-4-one) has been studied in vitro using the human adenocarcinoma cell line, Caco-2. The transport of DFO and L1 has also been compared with that of their iron-bound complexes, ferrioxamine (FO) and L1(3)-Fe, respectively. We report an apparent permeability coefficient (Papp) value for DFO of 0.170 x 10(-7) +/- 0.080 cm s-1. The Papp value of L1 was 1.297 x 10(-5) +/- 0.133 cm s-1. The Papp values of their iron bound complexes FO and L1(3)-Fe are 0.230 x 10(-7) +/- 0.065 cm s-1 and 2.356 x 10(-6) +/- 0.365 cm s-1, respectively. We have shown that the transport of DFO and FO is similar in the Caco-2 cell system. The transport of L1, however, is greatly reduced when complexed to iron. The value for total uptake after 60 min for DFO into the Caco-2 cells was 1.49 +/- 0.09 x 10(-3) nmol per filter. The values for total uptake after 60 min for L1 and L1(3)-Fe were 0.37 +/- 0.03 nmol per filter and 0.04 +/- 0.01 nmol per filter, respectively. Our results indicate that the poor oral bioavailability of DFO can be attributed to the low epithelial permeability of the molecule coupled with its size (mol wt 656). In contrast, the oral bioavailability observed with L1 is due to the high lipophilicity and low molecular weight (mol wt 139) of the molecule. We believe that these differences between the two molecules account for L1 being better orally absorbed than DFO.

Biological Transport↗
PubMed1993

Urinary stones in children in Zaria.

In a period of 16 years, 22 boys whose ages ranged from 10 months to 15 years were treated for stones occurring predominantly in the lower urinary tract. These boys represented 9.6/100,000 paediatric admissions, indicating the rarity of urinary stones in children in Zaria. Congenital obstructing lesions were present in 13 (59%) and the urine was infected in eight cases, most frequently by Klebsiella spp.

Adolescent↗
PubMed1993

Urethral calculi: a review.

The diagnosis and management of 19 patients treated for urethral calculi over a 16-year period are reviewed. All were males, had a median age of 20 years, and urinary retention was the most common presenting symptom. Thirteen (68%) had anterior urethral calculi; 14 (74%) had anatomic alterations of the urethra; and 12 (80%) of the patients who had urine culture had urinary infection. External urethrotomy and open cystolithotomy were the methods used for the removal of calculi in most instances.

Adolescent↗
PubMed1992

Paediatric empyema thoracis in Zaria, Nigeria.

From 1977 to 1986 at the Ahmadu Bello University Hospital in Zaria, the diagnosis of empyema thoracis was made in 150 children representing 0.35% of all paediatric admissions. Empyema was a complication of pneumonia in 98 of 100 cases reviewed, of whom 70 were 3 years old or younger. There was no sex or side preference. Fifty-nine patients were severely ill on admission, with a mean symptom duration of 21 days. In many of them, anaemia, protein-energy malnutrition, measles and gastro-enteritis were present as associated illnesses. Staphylococcus aureus was the most frequent bacterial isolate (39%), of which 83% of the cultures were sensitive to cloxacillin. Adequate rehydration, systemic antibiotics and tube thoracostomy drainage performed in 80 patients were more successful than repeated needle aspiration. Fourteen of the children died, six absconded and 80 were discharged home.

Adolescent↗
PubMed1992

Studies on urea cycle enzyme levels in the human fetal liver at different gestational ages.

Urea cycle enzymes involved in the detoxification of ammonia were studied in liver tissues of 57 male and 49 female fetuses of different age groups ranging from 13 to 36 wk of gestation. Surgical wedge biopsies of liver from 18 male and 12 female adults were used as controls. Significant enzyme activity was found to be present as early as the 13th wk of gestation. As gestational age advanced, enzyme activity gradually increased, reaching about 90% of the adult activity by the 36th wk of gestation.

Adult↗
PubMed1992

Breast cancer in Zaria, Nigeria.

A retrospective analysis of the clinical records of 129 women with breast cancer seen at the Ahmadu Bello University Teaching Hospital, Zaria has been carried out. The patients were young (median age 38 years), 64% were premenopausal and 89% were parous and had practised prolonged breastfeeding. Patients typically presented with massive breast tumour (median diameter 10 cm) with matted axillary lymph nodes in 57%. Eighty-eight per cent of patients had stage III or IV disease, and in 85% the histological tumour type was infiltrating ductal carcinoma. Mastectomy was the main mode of treatment and the default rate both before and after treatment was high. The median crude survival period for our patients was only 1.5 years. The survival disadvantage is probably the result of the combined effect of delayed presentation by the patients, the preponderance of biologically very aggressive tumours and our grossly limited therapeutic modalities.

Adult↗
PubMed1992

Adult empyema in Zaria, Nigeria.

The clinical records of 41 adult patients who were treated for empyema thoracis at the ABU Hospital, Zaria from 1974 to 1986 have been reviewed. Twenty six (63%) of the patients were younger than 34 years. Bacterial pneumonia, pulmonary tuberculosis and chronic bronchitis were the underlying illnesses in 32 (78%) while advanced malignancies were present in two others. Gram-negative bacilli were as important as the gram-positive cocci as causative agents in the 16 patients whose pleural aspirates were culture-positive. Closed chest tube drainage was most often effective when combined with antibiotics. Overall, 5 patients died, 2 absconded, 34 were discharged home but the default rate from the follow up clinic was high.

Adolescent↗
PubMed1991

Isolation and characterisation of clones from the Caco-2 cell line displaying increased taurocholic acid transport.

The Caco-2 cell line has been cloned by the limiting dilution technique. Clones and reclones have been tested for growth characteristics, transepithelial electrical resistance, ability to transport taurocholic acid specifically and morphological homogeneity. Although clones have similar growth patterns to the parental population they display a variety of electrophysiological, biochemical and morphological characteristics. One clone, clone 40, has been characterised in detail and shown to transport significantly higher amounts of taurocholic acid. Moreover, this clone displays morphological homogeneity and is stable with respect to this parameter over an extended time period.

Adenocarcinoma↗
PubMed1989

[Mortality at a pulmonary tuberculosis service in Dakar over a 10-yr period (January 1976-December 1985)].

Despite more admissions, deaths in the Pneumophthisiological Unit remained relatively stable over the ten year period at around 14%. Two thirds of the deaths were males. Most deaths concern young adults aged between 40 and 60 years, but a considerable number are somewhat older or somewhat younger. All ethnic groups are represented, with a predominance of Woloffs. Of the killer sickness, tuberculosis is clearly in the lead accounting for 75% of the cases. Other afflictions, such as broncho-pulmonary cancer, are beginning to cause problems. As far as length of admission is concerned, tuberculosis is again in the lead followed by other etiologies.

Adolescent↗