Cross-clade p17 peptide recognition by antisera to HGP-30, a 30-amino acid synthetic peptide antigen from HIV type 1 p17

HGP-30, a 30-amino acid synthetic peptide analog of HIV-1SF2 p17 (aa 86-115), was used to immunize both mice and humans. Since the amino acid sequence of HGP-30 is relatively conserved among different HIV-1 strains and clades, experiments were carried out to determine if antisera obtained by immunizing animals and humans can recognize HGP-30-related peptide consensus sequences belonging to different clades. Results show that antisera from mice immunized with HGP-30 can recognize clade B and C and to a lesser degree clade A and E consensus sequences of HIV-1, in addition to recognizing HGP-30 sequence. The cross-clade recognition was higher in mouse sera obtained on day 42 than on day 14 or 28. MPL/SE and Novasomes were better adjuvants than alum in inducing antibodies that showed cross-clade recognition and IgG2a and IgG2b antibody isotypes. Similar cross-clade recognition was observed in several sera from humans immunized with an HGP-30/KLH/alum formulation. The human sera from HGP-30-immunized subjects evaluated for cross-clade recognition of HGP-30 peptides were from subjects whose cells showed significant protection from HIV infection on virus challenge in the hu-PBL-SCID mouse model. These studies suggest that HGP-30 may be useful as a candidate vaccine antigen for populations in countries with prevalence of different HIV clades.

Economic evaluation of a pit and fissure dental sealant and fluoride mouthrinsing program in two nonfluoridated regions of Victoria, Australia

OBJECTIVES

This study assessed the cost effectiveness of a three-year school-based pit and fissure dental sealant and fluoride mouthrinsing program in two nonfluoridated regions in Victoria, Australia.

METHODS

The analysis was based on a community intervention in five schools comparing an intervention group receiving the pit and fissure dental sealant, a weekly fluoride mouthrinsing, and an annual oral hygiene education session, with a control group receiving oral hygiene education only. The study measured mean differences in DMFS increments between study groups.

RESULTS

The mean discounted DMFS difference in increment (DMFS avoided) between study groups was 1.22 DMFS over three years. The incremental cost-effectiveness ratio comparing intervention to control group varied between a net savings of $7.00 to a cost of $35.60 per DMFS avoided, depending on assumptions used in the analysis. Results were sensitive to assumptions on program effectiveness, dental examination rates, and baseline DMFS of students. The program became more cost effective with each successive year of the program.

CONCLUSIONS

The introduction of such a preventive program in nonfluoridated regions of Victoria will represent an efficient use of community resources. Policy issues that need consideration include whether to target areas where adolescents have a history of high dental disease experience, and whether dentists or auxiliaries are used as service providers. The need exists for a systematic evaluation (including an economic evaluation component) of dental prevention and treatment programs in Australia.

The effect of clinical targets on productivity and perceptions of clinical competency

This study investigated the effect of clinical targets on clinical productivity and perceptions of clinical competency of final-year undergraduate dental students. Students were randomly divided into two equal groups. One group was set annual numerical clinical targets while the other had no targets. All final-year students and final-year clinical teachers were asked to complete a questionnaire rating six different aspects of student clinical competency at the end of semester 1 and semester 2. Changes in perception of clinical competency by students and clinical teachers were compared between the target and no-target groups and between students and clinical teachers. The clinical output of both groups was measured. There was no significant difference in performance between the target and no-target group as assessed by clinical teacher or by student self-assessment. However, by the completion of the study the clinical teachers scored the students (irrespective of group) significantly lower for clinical competency than students assessed themselves. There was no significant difference between the productivity of the two groups. The setting of clinical targets had no measurable effect on the perceived clinical competency or productivity of this group of undergraduate dental students.

Responding to health changes: a case study of dental health conditions and systems in Japan and Australia

This paper presents an analysis of the main policy and organisational issues confronting dental health systems in Japan and Australia. Using the changes in the epidemiology of dental disease (the oral disease which still affects much of public dental health planning) as evidence of fundamental differences in the dental health systems of the two countries, the analysis seeks to illuminate, first, the structures and processes in both nations to review and implement changes to educational practices and workforce planning and, second, the constraints on each nation's capability to respond quickly and appropriately to the changing dental health needs. It is argued that Japan's ability to rapidly change its oral health outcomes, its dental educational system and its traditional workforce structure and service-mix, is more constrained than appears to be the case in the Australian dental system. The major barriers to Japan's ability to change appear to lie in both its traditional cultural decision-making processes and in a series of specific health and educational structures which place high reliance on a private educational system for health providers, a national insurance system which rewards treatment under a fee-for-service reimbursement scheme and the lack of a formal, transparent, infra-structure for planning health priorities. Barriers to Australia achieving culturally appropriate oral health outcomes for the next century appear more related to whether national unity in goal setting and implementation strategies can be achieved. The constraints in Australia are related to its federal system and to the low priority given to financing public dental services.

Mental health. Commissioned for service

GPs often lack the data to make well-informed judgements about commissioning mental health services. A multi-agency group, including a multifund, health authority and social services, has developed service agreements which are proving useful to practices. The system provides primary care commissioners with clinical information linked to expenditure for all patients with a mental illness.

How easy is it for young people to obtain cigarettes, and do test sales by trading standards have any effect? A survey of two schools in Gateshead

Smoking prevalence among young people continues to rise and cigarettes are easily available from many shops. Test sales are used by trading standards departments to try to reduce under-age sales, but it is not known whether this has any real impact on cigarette purchase and consumption. This study aims to evaluate the impact of test sales on purchase and consumption of cigarettes by young people. A survey of two schools in Gateshead, one in the intervention area and one acting as a control was carried out. A series of test sales were targeted to shops within 1.5 km of the intervention school. A questionnaire was administered in both schools among year 10 pupils, age 14-15 years, prior to the intervention and again 1 year later. The outcomes measured were number of successful test sales, reported availability of cigarettes and change in smoking prevalence following the intervention. Some 224 pupils from both schools were surveyed in 1995 and 163 pupils from the new cohort of year 10 pupils in 1996. Prior to the intervention, the levels of regular smoking in the intervention school were 39% for girls and 26% for boys. In the control school these levels were 24% and 14%, respectively. The intervention by trading standards resulted in no purchases and hence no prosecutions, but children reported being able to buy cigarettes with ease from the nearby shops; only three (2.5%) reported sales refused in 1995 and five (5.8%) in 1996. Not surprisingly there was no significant change in smoking prevalence in either school in 1996. This study suggests that test sales may not be effective in modifying cigarette availability to young people and that they are not a reliable measure of access to cigarettes by children.

The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cells

Cryptolepine hydrochloride is an indoloquinoline alkaloid isolated from the roots of Cryptolepis sanguinolenta. It is characterized by a multiplicity of host-mediated biological activities, including antibacterial, antiviral, and antimalarial properties. To date, the molecular basis for its diverse biological effects remains largely uncertain. Several lines of evidence strongly suggest that DNA might correspond to its principal cellular target. Consequently, we studied the strength and mode of binding to DNA of cryptolepine by means of absorption, fluorescence, circular, and linear dichroism, as well as by a relaxation assay using DNA topoisomerases. The results of various optical and gel electrophoresis techniques converge to reveal that the alkaloid binds tightly to DNA and behaves as a typical intercalating agent. In DNAase I footprinting experiments it was found that the drug interacts preferentially with GC-rich sequences and discriminates against homo-oligomeric runs of A and T. This study has also led to the discovery that cryptolepine is a potent topoisomerase II inhibitor and a promising antitumor agent. It stabilizes topoisomerase II-DNA covalent complexes and stimulates the cutting of DNA at a subset of preexisting topoisomerase II cleavage sites. Taking advantage of the fluorescence of the indoloquinoline chromophore, fluorescence microscopy was used to map cellular uptake of the drug. Cryptolepine easily crosses the cell membranes and accumulates selectively into the nuclei rather than in the cytoplasm of B16 melanoma cells. Quantitative analyses of DNA in cells after Feulgen reaction and image cytometry reveal that the drug blocks the cell cycle in G2/M phases. It is also shown that the alkaloid is more potent at inhibiting DNA synthesis rather than RNA and protein synthesis. Altogether, the results provide direct evidence that DNA is the primary target of cryptolepine and suggest that this alkaloid is a valid candidate for the development of tumor active compounds.

Ultrasound-guided compression of femoral pseudoaneurysm: an audit of practice

OBJECTIVE

To audit the practice of ultrasound-guided compression of femoral pseudoaneurysm in a specialist cardiac hospital.

BACKGROUND

Femoral pseudoaneurysm is an important complication of invasive cardiac procedures. This may require surgical repair but more recently ultrasound-guided compression for ablating pseudoaneurysms has been described. We investigated the success of such a procedure.

METHODS AND RESULTS

In a 26-month period, 56 patients were referred for ultrasound scanning to exclude the formation of a femoral pseudoaneurysm following transfemoral cardiac procedures. During this period, 5756 diagnostic cardiac catherisations and 1165 coronary angioplasties were performed in our hospital (total of 6921 procedures). Of the 56 patients, 20 patients (0.3% of 6921) were found to have a pseudoaneurysm. Ultrasound-guided compression was attempted in 11 patients and was successful in 7 patients (64%). Of the patients who had failed ultrasound-guided compression, 2 proceeded to surgical closure and 2 were treated conservatively with compression stockings to facilitate thrombosis of the pseudoaneurysm. Of those who did not have an attempted ultrasound-guided compression of the pseudoaneurysm (n=9), a conservative approach consisting of resting the leg was adopted to facilitate spontaneous thrombosis of the pseudoaneurysm; repeat ultrasound scanning was needed for follow-up and 1 patient required surgical closure in this group.

CONCLUSIONS

In patients with a femoral pseudoaneurysm following an invasive cardiac procedure, ultrasound-guided compression may be useful as an immediate step to ablate the pseudoaneurysm. This avoids either prolonged leg rest and repeated ultrasound scanning or surgical intervention. However, ultrasound-guided compression is not always successful; in these patients, a period of conservative management with repeat ultrasound scanning is appropriate to allow for the possible spontaneous thrombosis of the pseudoaneurysm. Surgical closure is needed in those patients whose pseudoaneurysm is enlarging, painful or remain patent.

Long-term prognosis in unstable angina. The importance of early risk stratification using continuous ST segment monitoring

AIMS

To assess the ability of clinical characteristics, admission ECG and continuous ST segment monitoring in determining long-term prognosis in unstable angina.

METHODS

Two hundred and twelve patients with unstable angina (mean age 59 years), presenting within 24 h of an acute episode of angina were recruited at three hospitals and treated with standardized medical therapy. All patients kept chest pain charts and underwent ST segment monitoring for 48 h. The occurrence of death, myocardial infarction, and need for revascularization was assessed over a median follow-up of 2.6 years.

RESULTS

The risk of death of myocardial infarction was greatest in the first 6-8 weeks after admission. Admission ECG ST depression and the presence of transient ischaemia predicted increased risk of subsequent death or myocardial infarction, whereas a normal ECG predicted a good prognosis. In 14 patients, ST segment monitoring provided the only evidence of recurrent ischaemia, and 72% of this group suffered an adverse event. Transient ischaemia and a history of hypertension were the most powerful independent predictors of death or myocardial infarction.

CONCLUSIONS

Adverse events in unstable angina occur early after admission and can be predicted by clinical and ECG characteristics, and by the presence of transient ischaemia during ST segment monitoring. Risk stratification by these simple assessments can identify patients with unstable angina at high risk.

New chart to evaluate weight faltering

A new chart was designed to aid accurate identification of weight faltering and failure to thrive. It provides guidance on the lower limits of expected weight gain for children, whatever their initial centile position. The chart's theoretical basis, the process of its construction, and its evaluation are described in this paper. Evaluation was by a self completion questionnaire, where respondents answered questions about a range of standardised growth patterns, plotted on old and new charts. Forty five health visitors, 28 general practitioner principals and registrars, and nine community paediatricians provided 328 chart ratings. These showed that the new format significantly increased the proportion of correctly rated charts (old: 45 (28%); new: 82 (51%)), with the greatest impact in severe cases. This suggests that the new chart improves the precision of judgments made about weight gain in infancy.

A study of the quality of perinatal autopsy in the former northern region. The Northern Perinatal Mortality Survey Steering Group

OBJECTIVE

To assess the quality of perinatal autopsy.

DESIGN

Review of all reports of post mortem examinations carried out following perinatal deaths from January 1994 to June 1994.

POPULATION

Former Northern Region of England.

METHODS

Assessment of post mortem reports concerning their content and interpretation, the assessment carried out by panel comprising a pathologist, obstetrician and paediatrician.

RESULTS

Reports were available for all 104 cases where post mortem examinations had been undertaken, of which 53 (51%) met the minimum standards for such autopsies proposed by the Royal College of Pathologists. Interpretative comments were judged to be adequate in 51 (49%).

CONCLUSIONS

The quality of perinatal autopsies is frequently poor. Improvement requires increased awareness of the potential value of the autopsy, and more consultation between pathologists, obstetricians and paediatricians.

Analysis of myosin heavy chain mRNA expression by RT-PCR

An assay was developed for rapid and sensitive analysis of myosin heavy chain (MHC) mRNA expression in rodent skeletal muscle. Only 2 microg of total RNA were necessary for the simultaneous analysis of relative mRNA expression of six different MHC genes. We designed synthetic DNA fragments as internal standards, which contained the relevant primer sequences for the adult MHC mRNAs type I, IIa, IIx, IIb as well as the embryonic and neonatal MHC mRNAs. A known amount of the synthetic fragment was added to each polymerase chain reaction (PCR) and yielded a product of different size than the amplified MHC mRNA fragment. The ratio of amplified MHC fragment to synthetic fragment allowed us to calculate percentages of the gene expression of the different MHC genes in a given muscle sample. Comparison with the traditional Northern blot analysis demonstrated that our reverse transcriptase-PCR-based assay was reliable, fast, and quantitative over a wide range of relative MHC mRNA expression in a spectrum of adult and neonatal rat skeletal muscles. Furthermore, the high sensitivity of the assay made it very useful when only small quantities of tissue were available. Statistical analysis of the signals for each MHC isoform across the analyzed samples showed a highly significant correlation between the PCR and the Northern signals as Pearson correlation coefficients ranged between 0.77 and 0.96 (P < 0.005). This assay has potential use in analyzing small muscle samples such as biopsies and samples from pre- and/or neonatal stages of development.

Altered platelet function detected by flow cytometry. Effects of coronary artery disease and age

Platelet activation state and responsiveness to physiological agonists were measured in 65 patients with documented coronary artery disease (54 male and 11 female; mean age, 58 years). Twelve patients (mean age, 52 years), selected at random from the male cohort, were compared with 12 age-matched male control subjects (mean age, 52 years) and with 10 normal, young male subjects (mean age, 25 years). Whole-blood flow cytometry was used to measure platelet activation status ex vivo and platelet responsiveness to physiological agonists in vitro. Peripheral blood samples were analyzed for bound fibrinogen and expression of P-selectin, GPIb, and GPIIb-IIIa at rest and in response to ADP (0.1 to 10 mumol/L) and thrombin (0.02 to 0.32 mu/mL). No significant differences were seen in the basal levels of fibrinogen binding between any of the groups, but P-selectin expression was significantly lower in patients compared with age-matched control subjects (P = .0005). When stimulated with agonists, patients' platelets had significantly decreased fibrinogen binding (P < .03) but no difference in P-selectin expression compared with the age-matched group. Both agonist-induced fibrinogen binding and P-selectin expression were, however, higher in the young subjects compared with either the older control group or the patients (P < .05). GPIb and GPIIb-IIIa expression were lowest in the patients with angina and highest in the young control subjects, with levels in the age-matched control subjects falling between these values. Data from the total patient cohort (n = 65) were identical to those in the smaller cohort (n = 12). In conclusion, atherosclerosis impairs platelet aggregatory responses (fibrinogen binding) over and above the decreased response seen with age. Platelet degranulation (P-selectin expression) is also impaired in patients with coronary artery disease, but only in comparison with younger subjects, not age-matched controls.

Renal abnormalities on obstetric ultrasound as a presentation of DiGeorge syndrome

We describe three pregnancies that presented with renal anomalies on obstetric ultrasound as the main abnormality and were subsequently found to have interstitial deletions within chromosome 22q11. A cardiac defect, double-outlet right ventricle, was also seen in the first case. Amnio infusion was refused in the second pregnancy and the perimembranous ventricular septal defect was not identified prior to termination. In the third case, there was no cardiac defect. The genitourinary abnormalities were a right hydroureter and hydronephrosis with a ureterocele bulging into the bladder lumen, bilateral multicystic kidneys with associated oligohydramnios, and a left multicystic kidney with right renal agenesis and associated oligohydramnios. Absence of thymus at autopsy in all three cases led to fluorescent in situ hybridization studies looking for the submicroscopic deletion of chromosome 22q11 associated with DiGeorge syndrome.

Incidence and nature of feeding problems in young children referred to a paediatric HIV service in London: FEAD screening

A detailed screening assessment was carried out on two matched groups of young children; one group was HIV-infected and the other was not. Screening included assessments of growth, development and food intake. Parents were also interviewed about their child's feeding and mealtime behaviours. Half of the HIV-infected children were reported with serious feeding problems; significantly higher than in the uninfected group. More of the children in the HIV-infected group were found to have poorer growth and developmental weaknesses than in the uninfected group. A combination of physical and psychological factors are suggested as contributing to these feeding difficulties. Early monitoring of feeding behaviours, daily routines and food intake, together with systematic growth and developmental measures are suggested as important components in the care and management of HIV-infected children.