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P Mensah

Publications and source records attributed to P Mensah.

16 recordsLinked to original sources
PubMed2004

Outcome and prognostic factors in advanced Hodgkin's disease treated with high-dose chemotherapy and autologous stem cell transplantation: a study of 341 patients.

BACKGROUND: The reported probability of survival of patients with Hodgkin's disease (HD) following high-dose chemotherapy with autologous stem cell transplantation (HDC/ASCT) is 35-65% at 5 years. The Polish Lymphoma Research Group investigated retrospectively prognostic factors for overall survival (OS) and event-free survival (EFS), and the risk of secondary malignancies in a large series of patients who underwent HDC/ASCT. PATIENTS AND METHODS: The data of 341 consecutive patients treated in 10 centers from 1990 to 2002 were collected and analyzed. RESULTS: The actuarial 5-year OS and EFS were 64% [95% confidence interval (CI) 57% to 71%] and 45% (95% CI 39% to 51%), respectively. In the multivariate model, unfavorable prognostic factors for EFS were less than partial response at the time of ASCT [relative risk (RR), 2.92 (95% CI 1.68-5.08); P<0.001] and three or more previous chemotherapy lines (RR, 2.16; 95% CI 1.42-3.30; P<0.001). These two factors were also associated with unfavorable OS (RR, 3.32; 95% CI 1.90-5.79; P<0.001 and RR, 2.34, 95% CI 1.51-3.64; P<0.001). Five-year cumulative risk of secondary malignancy was 8.4% (95% CI 2% to 13%) and the only identified risk factor was splenectomy (P=0.02). CONCLUSIONS: HDC/ASCT should be considered early in the course of disease for patients with a response after standard therapy.

Adolescent↗
PubMed2003

Antibiotic resistance and genotyping of clinical group B Salmonella isolated in Accra, Ghana.

AIMS: The purpose of this study was to investigate the antibiotic resistance and clonal lineage of serogroup B Salmonella isolated from patients suspected of suffering from enteric fever in Accra, Ghana. METHODS AND RESULTS: Serogroup B Salmonella were isolated from blood (n=28), cerebral spinal fluid (CSF) (n=1), or urine (n=2), and identified based on standard biochemical testing and agglutinating antisera. Isolates were examined for their susceptibility to ampicillin, chloramphenicol, tetracycline and trimethoprim-sulfamethoxazole. Most of the isolates could be classified as multiple-drug resistant. Furthermore, the genetic location of resistance genes was shown to be on conjugative plasmids. Genetic fingerprinting by plasmid profiling, enterobacterial repetitive intergenic consensus (ERIC)-PCR, and repetitive element (REP)-PCR were performed to determine the diversity among the isolates. Plasmid profiling discriminated five unique groupings, while ERIC-PCR and REP-PCR resulted in two and three groupings, respectively. CONCLUSIONS: A high rate of antibiotic resistance was associated with the Salmonella isolates and the genes responsible for the resistance are located on conjugative plasmids. Also, there appears to be minimal diversity associated with the isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: As a result of the increasing antibiotic resistance among bacteria of all genera, surveys to monitor microbial populations are critical to determine the extent of the problem. The inability to treat many infectious diseases with current antibiotic regimens should prompt the medical community to be more prudent with its antibiotic use.

Ampicillin Resistance↗
PubMed2002

High-dose chemotherapy with autologous stem cell transplantation is an effective treatment of primary refractory Hodgkin's disease. Retrospective study of the Polish Lymphoma Research Group.

We analysed the treatment outcome of primary refractory HD patients managed with high-dose chemotherapy and haematopoietic cell transplantation. Data of 65 adult patients who underwent HDC/ASCT in nine Polish centres for primary resistant Hodgkin's disease between June 1991 and July 2000 were collected retrospectively. Response rate to HDC/ASC: CR, 54%; PR, 20%; less than PR, 15%; early deaths, 11%. Actuarial 3-year OS and PFS were 55% and 36%, respectively. In multivariate analysis, lack of bulky lymph nodes and use of immunotherapy were favourable factors for both OS and PFS. IPF <3 at the time of transplantation was predictive for PFS. However, the prognostic impact of immunotherapy should be interpreted with caution since this group included more patients who achieved CR after HDC/ASCT. The results of HDC/ASCT are encouraging and confirm earlier findings. The role of immunotherapy should be further investigated in prospective trials.

Adolescent↗
PubMed2001

Campylobacter, Salmonella, Shigella and Escherichia coli in live and dressed poultry from metropolitan accra.

This study on the microbiology of chicken assessed a total of 97 live birds from three selected farms and 87 carcasses/chicken parts from two supermarkets, two open markets and one wholesale outlet (cold store) in the Accra metropolis. Campylobacter spp. were isolated from 14 (14.4%) gut contents of live birds from three farms. None of the frozen birds were positive for Campylobacter spp. These isolates were sensitive to most common antibiotics but not to ampicillin and tetracyclines. Salmonella spp. were isolated from 7 (7.2%) gut contents and 13 (6.8%) carcasses and were resistant to erythromycin. cefotiam, penicillin, ampicillin and cefadroxil. Samonella spp. had varied susceptibilities to nalidixic acid, chloramphenicol and minocyclin. No Shigella spp. was isolated from any of the live birds but 6 (6.9%) of imported chicken samples from the cold store and two markets were positive. Fosfomycin and chloramphenicol were the only antibiotics effective against these isolates. Twelve different Escherichia coli serovars were identified from the total of 21 positive samples. These, in order of magnitude isolated, are E. coli 0158 (14.3%), 0125 (14.3%), 025 (9.5%), 028ac (9.5%), 0159 (9.5%). 015 (9.5%), 0126 (9.5%), 063 (4.8%), 0143 (4.8%), 026 (4.8%), 078 (4.8%), 0164 (4.8%). Cefadroxil, ampicillin, penicillin, cefotiam, tetracycline and erythromycin were ineffective against all strains of E. coli isolated. Minocyclin was effective against all strains with the exception of E. coli 0159, 025, 0164 and 063, which were moderately susceptible. All strains with exception of E. coli 0164 were susceptible to fosfomycin. Nalidixic acid, chloramphenicol, kanamaycin, ceftrioxone and amoxycillin all showed varied effectiveness against the strains isolated. It is concluded that imported and locally produced chicken is a potential source of multiple-antibiotic-resistant enteropathogenic bacteria. Measures to improve the microbial quality of chicken are discussed.

Animals↗
PubMed1999

[Methods of mobilizing hematopoietic cells, their collection using cell separation, purging--processing of pathologic cells and enrichment with CD 34+ cells--negative and positive selection].

Autological transplantation of bone marrow as well as hematopoietic and precursor cells obtained from peripheral blood with the use of cell apheresis is a therapy applied in the treatment of hematological diseases and solid tumours. The mobilization of hematopoietic cells is performed by applying cytostatic drugs and/or recombinant growth factors (G-CSF, GM-CSF). The collection of CD 34+ cells is performed by using cell separators. An important role in the transplantation procedure is played by purging techniques of transplantation material from residual neoplastic cells (negative selection) or isolation of hematopoietic cells (positive selection). The considerable progress in this field is connected with the implementation of Immunoadsorbtive or magnetic methods as well as those of molecular biology. The improvement of the procedure of hematopoietic cells transplantation and its efficacy is caused by the stimulation of the hematopoiesis by using the combination of cytokines (G-CSF, GM-CSF, IL-3, SCF) and purging of the hematopoietic cells obtained from the cellular apheresis.

Antigens, CD34↗
PubMed1999

[Hodgkin's disease--diagnostic basis and therapy in light of randomized clinical trials].

Hodgkin Disease has a relatively good prognosis and high curability due to the effectiveness of risk adapted treatment. Protocol currently used at the Department of Haematology in Cracow is based on randomised multicentre clinical trials, summarised in this paper. Proper choice of the first line treatment is most important for overall survival--no salvage therapy for resistant or recurrent disease is equally effective. High dose chemotherapy with autologous stem cell support should be considered in certain clinical situations, as partial response or relapse after conventional treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Adsorptive control of water in esterification with immobilized enzymes. Continuous operation in a periodic counter-current reactor.

A periodic counter-current adsorptive-reactor system is developed to carry out continuous esterifications in organic solvents with immobilized enzymes. The system comprises a number of fixed-beds distributed between a reaction-adsorption zone and a regeneration zone and operated in a "merry-go-round" sequence. Water formed in the reaction is adsorbed preventing the formation of a free-water phase and deactivation of the biocatalyst. The adsorbed water is, in turn, recovered by desorption in the regeneration zone. The concept is tested experimentally on a laboratory-scale using, as a model, the esterification of isoamyl alcohol and propionic acid in hexane catalyzed by an immobilized lipase. Pure isoamyl alcohol is used as a regenerant to remove excess water from the biocatalyst. In the periodic steady-state, improvements in ester productivity greater than 50% over that achievable with a conventional fixed-bed reactor are demonstrated experimentally with just two beds in a series arrangement. Use of a water-selective adsorbent in conjunction with the biocatalyst provides further improvements by reducing accumulation of water on the enzyme. A mathematical model is also developed to predict the thermodynamic activity of water along the reactor and describe the dynamic behavior of the system. The model, based on independently developed rate and equilibrium parameters, successfully predicts the experimental behavior and provides an effective tool for scale-up and optimization.

Adsorption↗
PubMed1998

Adsorptive control of water in esterification with immobilized enzymes: I. Batch reactor behavior.

Reducing the influence of an undesired product in an enzymatic reaction could have a significant impact on the productivity of such systems. Here, we focus on the removal of water formed during an enzymatic esterification in a batch reactor. A commercial immobilized lipase preparation, known as Lipozyme, is used as the biocatalyst and propionic acid and isoamyl alcohol dissolved in hexane are the substrates. In this system, the water formed will partition between the catalyst and the medium. As the more polar reactants are converted into the less polar ester product, the water is partitioned more towards the biocatalyst and the accumulation of water eventually causes lower reaction rates. Addition of a strong-acid cation exchange resin in sodium form is found to control the water accumulation on the biocatalyst without stripping the essential water needed for the enzyme to function and substantial improvements in conversion are achieved. A mathematical model is developed to describe the batch reaction behavior with and without added absorbent, which successfully predicts the behavior of water and its effects.

Adsorption↗
PubMed1998

Adsorptive control of water in esterification with immobilized enzymes: II. fixed-bed reactor behavior.

Experimental and theoretical studies are conducted to understand the dynamic behavior of a continuous-flow fixed-bed reactor in which an esterification is catalyzed by an immobilized enzyme in an organic solvent medium. The experimental system consists of a commercial immobilized lipase preparation known as Lipozyme as the biocatalyst, with propionic acid and isoamyl alcohol (dissolved in hexane) as the reaction substrates. A complex dynamic behavior is observed experimentally as a result of the simultaneous occurrence of reaction and adsorption phenomena. Both propionic acid and water are adsorbed by the biocatalyst resulting in lower reaction rates. In addition, an excessive accumulation of water in the reactor leads to a rapid irreversible inactivation of the enzyme. A model based on previously-obtained adsorption isotherms and kinetic expressions, as well as on adsorption rate measurements obtained in this work, is used to predict the concentration and thermodynamic activity of water along the reactor length. The model successfully predicts the dynamic behavior of the reactor and shows that a maximum thermodynamic activity of water occurs at a point at some distance from the reactor entrance. A cation exchange resin in sodium form, packed in the reactor as a selective water adsorbent together with the catalyst particles, is shown to be an effective means for preventing an excessive accumulation of water formed in the reaction. Its use results in longer cycle times and greater productivity. As predicted by the model, the experimental results show that the water adsorbed on the catalyst and on the ion exchange resin can be removed with isoamyl alcohol with no apparent loss in enzyme activity.

Adsorption↗
PubMed1995

Feeding of lactic acid-fermented high nutrient density weaning formula in paediatric settings in Ghana and Nigeria: acceptance by mother and infant and performance during recovery from acute diarrhoea.

A period of acute diarrhoea in infants is often associated with anorexia and weight loss. Catch-up growth is, therefore, necessary and this depends very much on the type of food, in terms of nutrient density, protein quality and digestibility, given to the child. Fermented (F) and non-fermented (NF) maize-soybean porridges of increased nutrient density were formulated and compared with traditionally fermented maize-only porridge (P) for acceptability using mothers in peri-urban Ghana as well as urban Nigeria as subjects. Subsequently, infants hospitalised in paediatric wards for acute diarrhoea, from the same communities in both countries, were assigned randomly to one or other of the three porridges. Infant subjects in all cases fell within the ages of 6-15 months. Complementary to regular breast-feeding, infants could consume as much porridge as they wanted and their total daily consumption was interpreted as an indication of acceptance. Although mothers in both the environments of Ghana and Nigeria rated P as more acceptable than F and NF, no significant difference was recorded in the quantitative intake by infants of the three formula groups. By adding enzyme-rich cereal malt flour (at the 1-5% level by weight) as a viscosity-thinning agent to F and NF porridges, it was possible to feed these porridges to infants at total solids concentration levels of 20-25% (wet basis) which is approximately double the solid matter content of the P porridge. Consequently, the daily nutrient intake by infants consuming F and NF porridges was considerably higher compared to the P porridge group. It is concluded that the concept of high nutrient density weaning foods is a feasible vehicle for an improvement of nutrient supply to infants.

Acute Disease↗
PubMed1991

Antimicrobial effect of fermented Ghanaian maize dough.

Unhygienic conditions of a typical rural community in a developing country were simulated in the laboratory by inoculating fermented maize dough porridge with Shigella flexneri and enterotoxigenic Escherichia coli (ETEC). The antimicrobial effects of the different processes involved in the preparation of fermented maize dough porridge were assessed. The soaking process reduced the pH but no antimicrobial effect against shigella and ETEC was noted. Unfermented maize dough did not inhibit any of the test strains. When the fermentation process had become established, half of the strains tested were inhibited by the fermented maize dough when examined 8 h after inoculation. Cooking the fermented maize dough into porridge reduced the antimicrobial effect but there was still significant inhibition of pathogens. This suggests that the antimicrobial effect of fermented maize dough is not due to pH per se. Fermentation of maize dough appears to be a useful strategy for reducing contamination of weaning foods by Sh. flexneri and ETEC. The possible nature of the antimicrobial agent(s) produced during the fermentation of maize dough is discussed.

Escherichia coli↗