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Biomedical subjects

J Cohen

Publications and source records attributed to J Cohen.

At least 19 recordsLinked to original sources
PubMed2007

Safety and immunogenicity of the RTS,S/AS02A candidate malaria vaccine in children aged 1-4 in Mozambique.

BACKGROUND: The development of a malaria vaccine remains a public health priority for sub-Saharan Africa. RTS,S/AS02A candidate malaria vaccine has been shown to be safe and immunogenic in previous studies in adults and staggered dose-escalation studies in children in The Gambia. However, genetic features and the intensity of malaria transmission may modify the safety and immune response of a vaccine. OBJECTIVE: We carried out a phase I, double-blind randomized controlled trial in 60 children aged 1-4 in Mozambique to evaluate the safety, reactogenicity and immunogenicity of the paediatric vaccine dose (fixed 25 microg RTS,S in 0.25 ml) of RTS,S/AS02A, prior to undertaking a planned larger phase IIb proof-of-concept of efficacy study in the same population. METHOD: Children were randomized to receive either RTS,S/AS02A or Engerix-B vaccine. Monitoring of safety and reactogenicity included detailed clinical and laboratory analyses and assessment of adverse events (AEs). RESULTS: The RTS,S/AS02A was found to be safe and well tolerated. Serious adverse events were balanced between both groups and none was related to vaccination. The frequency of adverse events reported with RTS, S/AS02A was comparable to previous studies in children. Grade 3 AEs were infrequent (one case of pain, one of fever in each group and some swelling greater than 20 mm in diameter), transient and resolved without sequelae. RTS,S/AS02A was highly immunogenic for anti-circumsporozoite protein antibody response and induced a strong anti-hepatitis-B surface antigen response.

Alanine Transaminase↗
PubMed2006

Complete genomic characterization and antigenic relatedness of genogroup III, genotype 2 bovine noroviruses.

Bovine enteric noroviruses form a genogroup, III, distinct from the 2 human norovirus genogroups, I and II. Two genogroup III genotypes were suggested by partial genomic analyses. In the present study, analysis of the full-length genome sequence of Bo/Newbury2/76/UK and the more contemporary Newbury2-like virus, Bo/Dumfries/1994/UK, showed that both were 7311 nucleotides in length and had three open reading frames (ORFs), amino acids motifs typical of noroviruses, and 95% or greater amino acid identities to each other in all regions of their genome. Apart from the ORF1 NTPase region, their ORF1 regions had less than 90% identity to the genogroup III genotype 1 Bo/Jena/80/DE virus, confirming two genogroup III genotypes. A close antigenic relationship was demonstrated by ELISA between the genotype 2 viruses, which will allow their serological diagnosis.

5' Untranslated Regions↗
PubMed2006

Does sodium hyaluronate- and carboxymethylcellulose-based bioresorbable membrane (Seprafilm) decrease operative time for loop ileostomy closure?

BACKGROUND: Adhesions can result in serious clinical complications and make ileostomy closure, which is relatively simple procedure into a complicated and prolonged one. The use of sodium hyaluronate and carboxymethyl cellulose membrane (Seprafilm) was proven to significantly reduce the postoperative adhesions at the site of application. The aim of this study was to assess the incidence and severity of adhesions around a loop ileostomy and to analyze the length of time and morbidity for mobilization at the time of ileostomy closure with and without the use of Seprafilm. METHODS: Twenty-nine surgeons from 15 institutions participated in this multicenter prospective randomized study. 191 patients with loop ileostomy construction were randomly assigned to either receive Seprafilm under the midline incision and around the stoma (Group I), only under the midline incision (Group II), or not to receive Seprafilm (Group III). At ileostomy closure, adhesions were quantified and graded; operative morbidity was also measured. RESULTS: All 3 groups were comparable relative to gender, mean age and number of patients with prior operations (26, 25 and 19, respectively). Group II patients were significantly more likely to have pre-existing adhesions than Group III patients (30.6% vs. 14.1%, p = 0.025). At stoma mobilization, significantly more patients in Group III than in Group I had adhesions around the stoma (95.2% vs. 82.3%, p = 0.021). Mean operative times were 27, 25, and 28 minutes, respectively (p = 0.38), with significant differences among sites. There was no significant difference in the number of patients needing myotomy or enterotomy (29, 27 and 24 patients, respectively), nor in the number of postoperative complications (7, 9 and 7 patients, respectively). CONCLUSIONS: When consistently applied, Seprafilm significantly decreased adhesion formation around the stoma but not operative times without any increase in the need for myotomy or enterotomy. These findings were not seen in the overall study population possibly due to the large number of surgeons using a variety of application techniques.

Adjuvants, Immunologic↗
PubMed2006

ESHRE Task Force on Ethics and Law 11: Posthumous assisted reproduction.

This article analyses the different ethical aspects of posthumous assisted reproduction. Two situations are distinguished: cases in which the gametes or embryos are used by the surviving partner and cases in which the gametes or embryos are made available for third persons. The moral evaluation of the procedure depends on whether the act is restricted to the existing parental project. A major difficulty for the moral evaluation is the inconclusiveness of the empirical data on the psychosocial development of children born after this procedure. The Task Force concluded that posthumous reproduction by a partner is acceptable if the following conditions are met: written consent has been given by the deceased person, the partner received extensive counselling and a minimum waiting period of 1 year is imposed before a treatment can be started. For use by third parties, the usual conditions for gamete and embryo donation apply.

Advisory Committees↗
PubMed2006

A community randomized controlled clinical trial of mixed carotenoids and micronutrient supplementation of patients with acquired immunodeficiency syndrome.

OBJECTIVE: This clinical trial aims to evaluate if natural mixed carotenoids supplementation can improve the health and survival of acquired immunodeficiency syndrome (AIDS) patients. DESIGN: A placebo-controlled, prospective, randomized, double-blind, multicenter clinical trial. SETTING: Community, tertiary care human immunodeficiency virus (HIV) clinics of the Canadian HIV Trials Network (CTN). PARTICIPANTS: Three hundred and thirty-one adults with advanced AIDS on conventional management were recruited during routine clinic visits. INTERVENTIONS: All participants, including 166 controls, received daily oral specially formulated multivitamins including vitamin A and trace elements; 165 treatment group participants received additional daily oral natural mixed carotenoids, equivalent to 120,000 IU (72 mg) of beta-carotene daily. Follow-up was quarterly at routine clinic visits. RESULTS: Mean (s.d.) follow-up was for 13 (6) months. Thirty-six participants died by 18 months. Serum carotene concentration <1.0 micromol/l was present in 16% participants at baseline. Despite variation in carotene content of the treatment medication, serum carotene concentrations increased significantly to twice the baseline levels to 18 months follow-up in participants who received carotenoids treatment compared with controls (P < 0.0001). Although not statistically significant, mortality was increased in participants who did not receive carotenoids treatment compared with those who did (HR time to death 1.76, 95% CI 0.89, 3.47, P = 0.11). In multivariate analysis, survival was significantly and independently improved in those with higher baseline serum carotene concentrations (P = 0.04) or higher baseline CD4 T-lymphocyte counts (P = 0.005). Adjusted mortality was also significantly and independently increased in those who did not receive carotenoids treatment compared with those who did (HR time to death 3.15, 95% CI 1.10, 8.98, P = 0.03). CONCLUSIONS: Low serum carotene concentration is common in AIDS patients and predicts death. Supplementation with micronutrients and natural mixed carotenoids may improve survival by correction of a micronutrient deficiency. Further studies are needed to corroborate findings and elucidate mechanism of action.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Role of first responders in detecting and evaluating elders at risk.

Delay in recognition of elder abuse and neglect may be especially problematic for the elder residing in relative isolation. Police and fire personnel may have a unique opportunity to identify vulnerable elders as they interact with them in the community. The present study was designed to evaluate first responders in northern Illinois to determine their approach to vulnerable elders they encounter in the course of their work. A survey instrument was completed by the first responder, immediately preceding an educational intervention conducted at the work location of the first responder. Most first responders had no standard approach for screening vulnerable elders. First responders already detect many elders who pose a risk to themselves or others, but such detection efforts are typically unstructured. A particular area where a more structured approach might be of value is in screening for risk related to firearms.

Aged↗
PubMed2006

Wide range of chromosome abnormalities in the embryos of young egg donors.

Embryo chromosome studies show high rates of abnormalities, above 50%, but most embryos studied were from patients aged 35 and older. The objectives of this study were firstly, to evaluate the rate of chromosome abnormalities in embryos from young egg donors, and secondly, to compare the range of chromosome abnormality rates between donors and non-egg donor cycles, both undergoing preimplantation genetic diagnosis (PGD) for infertility using fluorescence in-situ hybridization analysis with probes for chromosomes X, Y, 13, 15, 16, 18, 21, and 22. On average, only 43% of the embryos were chromosomally normal, while the comparison group had euploidy rates between 34 (age group 18-34) (P < 0.001) and 21% (age group 40-45) (P < 0.001). There was considerable variation between donor cycles, with almost one-third having less than 30% normal embryos. Also, within donors and recipients repeating several IVF cycles with PGD, only 29-56% of the second PGD cycles had similar rates of normal embryos to the first cycle, while in the comparison group it was 64%. The results can explain why some egg donors are successful whereas others are not, and may also show that a policy of PGD for first time egg donors is appropriate and indicated.

Adolescent↗
PubMed2006

Quality of in-hospital care for adults with acute bacterial meningitis: a national retrospective survey.

BACKGROUND: Most adults with bacterial meningitis and meningococcal septicaemia present to junior doctors who have limited experience of these conditions. In contrast to paediatric practice, data from industrialized countries with regard to current hospital management practice are lacking. AIM: To examine whether current practice meets recommended standards in hospital management of community-acquired bacterial meningitis and meningococcal septicaemia among adults. DESIGN: National audit of medical records. METHODS: We conducted a survey of all patients with acute bacterial meningitis and meningococcal septicaemia admitted to 18 randomly selected acute hospitals in England and Wales between 1 January 2000 and 31 December 2001. All stages of care, including pre-hospital management, initial hospital assessment, record keeping, and ongoing hospital and public health management, were assessed. RESULTS: We identified 212 cases of bacterial meningitis and meningococcal septicaemia; 190 cases remained in the final analysis. Clinical record keeping did not meet acceptable standards in 33% of cases. Parenteral antibiotics were given within 1 h of hospital arrival in 56% of cases, increasing to 79% among those with an initial differential diagnosis that included bacterial meningitis or meningococcal septicaemia. A full severity of illness assessment was made in 27%. The quality of clinical practice varied widely between hospitals. This was most pronounced in the timeliness of consultant review (p < 0.0005). DISCUSSION: The quality of adult clinical practice for bacterial meningitis and meningococcal septicaemia needs improvement. This study provides a tool for developing targeted interventions to improve quality of care and outcome among adults with life-threatening infections, both in the UK and in other countries.

Adolescent↗
PubMed2006

The immature reticulocyte fraction: a negative predictor of the harvesting of CD34 cells for autologous peripheral blood stem cell transplantation.

The optimal time for the harvesting of peripheral blood stem cells following chemotherapy and growth factors for autologous transplantation is based on the CD34 cell count. In this study, 51 patients having 59 stem cell mobilizations were assessed for the timing of the harvest by a CD34 cell count and an immature reticulocyte fraction (IRF). Results from 272 preharvest tests showed that when the CD34 cells were not harvestable, defined as a CD34 cell count of < 15 cells/microl, the IRF was always < or = 0.2. A low IRF resulted in a negative predictive value of 1 for the harvesting of stem cells. The IRF is therefore a valuable negative predictor of the timing of autologous stem cell harvesting.

Antigens, CD34↗
PubMed2006

Role of follow-on drugs and indications on the WHO Essential Drug List.

INTRODUCTION: The World Health Organization's Essential Drug List (EDL) contains first-in-class drugs and subsequent class entrants (follow-on drugs) deemed necessary to combat diseases prevalent throughout the world, with a special emphasis on developing nations. The EDL also includes originally approved and follow-on indications. There are opposing views regarding the value of follow-on drugs and indications. Critics suggest many follow-on drugs and indications offer little or no benefit to patients. Advocates counter that follow-on drugs offer advantages in terms of improved effectiveness, compliance and patient satisfaction. OBJECTIVE: In order to inform this debate on the value of follow-on drugs and indications we examined the numbers of follow-on drugs on the EDL and the extent to which follow-on indications are recommended. METHODS: We identified all 312 drugs on the 14th edition of the EDL, omitting 72 non-pharmaceutical entities. For the 240 pharmaceutical entities we ascertained whether the Food and Drug Administration (FDA) had approved them, and, if so, when each was approved. We chose a validated therapeutic classification system - the United States Pharmacopeia's Model Guidelines for Medicare formulary management - in order to distinguish first-in-class and follow-on drugs on the EDL. Specifically, we selected the formulary key drug type as our benchmark therapeutic class. We assigned each EDL drug to a formulary key drug type. We defined first-in-class drugs as the first in each formulary key drug type, and follow-on drugs as all other drugs in each formulary key drug type. We identified follow-on indications by comparing WHO-listed indications with the original approved indication(s) by the FDA. Finally, we examined the therapeutic rating (priority vs. standard) given by the FDA to follow-on drugs on the EDL. RESULTS: Sixty-three per cent of the EDL drugs were follow-ons; 15% of the indications were follow-on indications. Fourteen drugs were listed in multiple WHO (sub) groupings; and 49% of follow-on drugs were given a priority rating by the FDA. CONCLUSIONS: In light of the fact that the EDL only includes drugs and indications deemed essential, the large number of follow-on drugs, follow-on indications, and priority-rated follow-on drugs on the EDL suggest their importance. From a public policy perspective, it may prove counterproductive to erect hurdles that impede follow-on research and development.

Developing Countries↗
PubMed2006

Risk of ventriculoperitoneal shunt infections due to gastrostomy feeding tube insertion in pediatric patients with brain tumors.

OBJECTIVE: To determine the risk of ventriculoperitoneal (VP) shunt infections after percutaneous retrograde gastrostomy feeding tube (GT) placement in children with brain tumors. PATIENTS AND METHODS: All children (age 0-18 years) with primary brain tumors diagnosed and treated at the Hospital for Sick Children, Toronto, Canada, were subjected to a retrospective analysis. Two groups were identified: the study group included children with a VP shunt and a GT; the control group included children with VP shunts only. Each study patient was matched with 2 controls to compare the rate of infections (cohort comparative study). RESULTS: There were 1,167 children diagnosed and treated with primary brain tumors during the study period (1988-2003); 174 (15%) had a VP shunt and 23 (2%) children had both, a VP shunt and a GT. In the study group (n=17), GTs were inserted at a median time of 80 days (range 6-204 days) after VP shunts. VP shunt infection rate was 23.5% (4/17) compared to 8.8% (3/34) in the control group (OR 3.18; 95% CI 0.622-16.54, p=0.16). Three (75%) of the infection episodes in the study group presented with an ascending VP shunt infection directly related to the GT insertion or manipulation in the first 6 weeks. These GTs were inserted at 13, 47 and 49 days after VP shunt insertion. CONCLUSION: Placement of percutaneous retrograde GTs, in the acute phase, in children with brain tumors and VP shunts may increase the risk of ascending meningitis especially if there are early GT-related complications.

Adolescent↗
PubMed2005

ESHRE Task Force on Ethics and Law 10: surrogacy.

This 10th statement of the Task Force on Ethics and Law considers ethical questions specific to varied surrogacy arrangements. Surrogacy is especially complex as the interests of the intended parents, the surrogate, and the future child may differ. It is concluded that surrogacy is an acceptable method of assisted reproductive technology of the last resort for specific medical indications, for which only reimbursement of reasonable expenses is allowed.

Advisory Committees↗
PubMed2005

Fertility and ageing.

The late 20th century trend to delay birth of the first child until the age at which female fecundity or reproductive capacity is lower has increased the incidence of age-related infertility. The trend and its consequences have also stimulated interest in the possible factors in the female and the male that may contribute to the decline in fecundity with age; in the means that exist to predict fecundity; and in the consequences for pregnancy and childbirth. In the female, the number of oocytes decreases with age until the menopause. Oocyte quality also diminishes, due in part to increased aneuploidy because of factors such as changes in spindle integrity. Although older male age affects the likelihood of conception, abnormalities in sperm chromosomes and in some components of the semen analysis are less important than the frequency of intercourse. Age is as accurate as any other predictor of conception with assisted reproductive technology. The decline in fecundity becomes clinically relevant when women reach their mid-30s, when even assisted reproduction treatment cannot compensate for the decline in fecundity associated with delaying attempts at conceiving. Pregnancies among women aged >40 years are associated with more non-severe complications, more premature births, more congenital malformations and more interventions at birth.

Adult↗
PubMed2005

Taskforce 9: the application of preimplantation genetic diagnosis for human leukocyte antigen typing of embryos.

This 9th statement of the ESHRE Taskforce on Ethics and Law considers ethical questions and specific dilemmas concerning preimplantation genetic diagnosis for human leukocyte antigen typing of embryos. This application is particularly complex because the interests of the sick child needing a transplantation should be balanced against the interests of the future donor child who may result from the technique. It is concluded that, if parents intend to love the child, the creation and use as a donor is not inherently disrespectful.

Cloning, Organism↗