Mathematical modelling of infection and disease due to Neisseria meningitidis and Neisseria lactamica

BACKGROUND: Invasive meningococcal disease, due to Neisseria meningitidis, is an important cause of morbidity and mortality in young children and adolescents. Nasopharyngeal carriage of meningococci (MC), is most prevalent in young adults whereas carriage of Neisseria lactamica (LC), a related non-pathogenic organism, is most prevalent in young children. The objective of this study was to use modelling techniques to test hypotheses on the processes that govern the incidence of meningococcal disease (MD). METHODS: Deterministic compartmental models were fitted to age structured data sets of MC, LC and MD. RESULTS: The model most consistent with the available data sets is one where LC inhibits MC, an inhibition that lasts for a mean of 4.7 years. The hypothesis that LC also acts as a natural immunogen against MD was consistent with this model. The second peak of MD observed among adolescents could be due to the peak in the acquisition of MC in this age group. CONCLUSIONS: The role of LC as a natural immunogen against asymptomatic and symptomatic meningococcal infection was consistent with available field data. If the introduction of novel meningococcal vaccines into a population changes the prevalence of MC or LC, this could have a substantial impact on the effectiveness of immunization programmes. This paper demonstrates the potential utility of modelling to estimate these effects.     

Obstructive sleep apnea: Variations in surgical management

Forty patients with obstructive sleep apnea (OSA) were either treated by submucous resection, alone or by palatopharyngoplasty (PPP). Before surgery, each patient underwent a thorough sleep evaluation for the diagnosis of OSA. Of the 23 patients treated by submucous resection alone, eight had more than a 50% reduction in their apnea index and were considered successfully treated. Of the remaining 15, ten received a supplemental tongue retaining device (TRD). Five of the ten were markedly improved. The overall success rate in this group was 57%. Of the 17 patients treated by submucous resection and PPP, ten were treated successfully. Six of the remaining seven patients were subsequently treated with a TRD, which was successful in four. The overall success rate in this group was 82%.     

Inaccessible information is useless information: addressing the knowledge gap

The burdens of increasing information overload, time constraints, and the high human and financial costs of medical error, mean that doctors cannot practice high quality evidence-based medicine without the aid of decision support systems at the point of care. The physician's role is to formulate a management plan based on clinical judgment, the patient's unique circumstances and preferences, and the best available evidence. Clineguide is a clinical knowledge system that will integrate into the workflow to improve patient outcomes, reduce variability of care, and promote efficiency in the health care process. This article discusses some of the issues surrounding the provision of rapid, accurate, and accessible information to health care professionals.     

Comparison of clinical efficacy and safety of three professional at-home tooth whitening systems

A three-cell, randomized, parallel, investigator-blinded clinical trial was conducted to compare the efficacy and safety of three professional at-home tooth whitening systems, including Crest Professional Whitestrips (6.5% H2O2), Day White 2 (7.5% H2O2) and Nite White Excel 2 (16% carbamide peroxide equivalent). Ninety subjects were randomly assigned to three groups (30/group). Subjects were instructed to use the assigned whitener following the manufacturers' instructions. Clinical examinations at baseline, and on days 3, 7, 14, and 18 (Day White), or 21 (Crest Professional Whitestrips and Nite White) included the following parameters: 1) oral tissues; 2) tooth shade by the Vitapan Classical shade guide; 3) tooth shade by a chromameter with a jig; and, 4) tooth sensitivity and gingival irritation. The results showed significant shade reductions with time in all three groups. Nite White resulted in significantly greater shade reductions in periods between days 7, 14, or 21 and baseline than did the other two systems. Tooth sensitivity and gingival irritation, which were mostly mild and transient, occurred in all groups. It is concluded that all three whitening systems evaluated are effective and safe. Nite White Excel is superior to the other two systems because it provides a greater whitening efficacy with comparable or lower incidence of tooth sensitivity and gingival irritation.     

Avidity maturation following vaccination with a meningococcal recombinant hexavalent PorA OMV vaccine in UK infants

To date, there are no data assessing the utility of avidity indices as a surrogate marker for the induction of immunological memory following meningococcal serogroup B outer membrane vesicle (OMV) vaccination. We studied infants who had been immunized with three doses of a recombinant hexavalent PorA OMV vaccine at ages 2-4 months, together with a fourth dose at age 12-18 months. A control group had received a single dose of the same vaccine at age 12-18 months. As previously reported, serum bactericidal antibody (SBA) titres increased after each of the first three doses, with a significant increase observed from 6 months post third dose to 1 month post fourth dose. The geometric mean avidity indices (GMAI), against strain H44/76 OMVs, increased from 1 month post first dose to 1 month post third dose. Significant increases in GMAI were observed at 6 months post third dose and again following the fourth dose. At 32-42 months of age, though the SBA titres had returned to post first dose levels, the GMAI remained elevated. No increase in avidity was observed in the control group. Antibody avidity indices are useful laboratory markers for the priming of immunological memory following vaccination with meningococcal serogroup B OMV vaccines.     

Age-specific incidence rates for cytogenetically-defined subtypes of acute myeloid leukaemia

It is generally considered that most cancers arise following the accumulation of several genetic events and that as a consequence its incidence increases with age. We report a cytogenetic subgroup of acute myeloid leukaemia whose incidence is independent of age. This observation indicates that acute myeloid leukaemia can develop via multiple pathways, and underlines the importance of cytogenetics in understanding this disease.     

反应停治疗难治性多发性骨髓瘤25例

1临床资料我院2001-02/2004-01接受2个疗程卡氮芥 环磷酰胺 马法兰 泼尼松 长春新碱或2个疗程长春新碱 阿霉素 地塞米松方案化疗无效或复发的难治性多发性骨髓瘤患者25(男16,女9)例,年龄42～80(中位年龄57.2)岁.单用反应停口服治疗,起始剂量200 mg/d,如无不良反应,每周增加100 mg,根据患者耐受情况,最高剂量为600 mg/d,3 mo为1疗程.服药期间禁止使用糖皮质激素类药物及细胞毒药物.     

Venlafaxine in children, adolescents, and young adults with autism spectrum disorders: an open retrospective clinical report

Autism is characterized by social deficits, communication and language impairments, narrow restricted interests, repetitive behaviors, inattention, and hyperactivity. While selective serotonin reuptake inhibitors have demonstrated efficacy in treating core symptoms of autism, norepinephrine reuptake inhibitors have demonstrated efficacy in symptoms of attention-deficit hyperactivity disorder (ADHD). An open, retrospective clinical study with venlafaxine evaluated its effect on core symptoms of autism as well as associated features of ADHD. Ten consecutive subjects meeting Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), criteria for an autism spectrum disorder were treated with venlafaxine, initiated at 12.5 mg per day and adjusted on a flexible basis. Six of 10 completers were judged to be sustained treatment responders, by scoring 1 (very much improved) or 2 (much improved) on the Clinical Global Impressions improvement scale. Venlafaxine was effective in low dosages (mean, 24.37 mg/day; range, 6.25 to 50 mg/day) and was well tolerated. Improvement was noted in repetitive behaviors and restricted interests, social deficits, communication and language function, inattention, and hyperactivity. Controlled treatment trials with venlafaxine are warranted in autism spectrum disorders.     

Haematologists' approaches to the management of adolescents and young adults with acute leukaemia

Approaches to the management of adolescents and young adults with acute leukaemia were investigated by sending a questionnaire to hospitals identified as having diagnosed or treated patients aged 15-29 years. The responses demonstrated the types of hospital treating these patients, the haematologists' perceived practice for entry of patients to Medical Research Council (MRC) leukaemia trials and reasons for non-entry. Data were linked to MRC trials data to determine the proportion of patients aged 15-29 years at diagnosis in responding hospitals actually treated in MRC leukaemia trials in the 5 years preceding the questionnaire. Eighty-two per cent of haematologists stated that they entered patients 'always' or 'whenever possible' for acute myeloid leukaemia (AML) and 76% for acute lymphoblastic leukaemia (ALL), but actual entry rates from the study hospitals were 46% of 239 AML patients and 36% of 182 ALL patients. The reasons most commonly reported for not entering eligible patients to national leukaemia trials were clinician preference for one arm of an MRC trial, a regional study or non-trial protocol, and concern about workload and ethical approval.