Lipid modifying agents: mechanisms of action and reduction of cardiovascular disease

1. Recent studies (4S, CARE, WOSCOPS) with the HMG CoA reductase inhibitors have shown that reductions of total cholesterol and LDL cholesterol reduce the risk for a new fatal or non-fatal cardiac event by approximately 30-35%, providing LDL is decreased by 25-35%. 2. Preliminary data also suggest that achieved LDL levels around 3.2 mmol/L results in no greater reduction in new events than when LDL is lowered even further. 3. There is considerable debate, nonetheless, as to whether these reduction in cardiovascular events are entirely a consequence of LDL reduction or whether the lipid-modifying agents have effects on lipoprotein structure, endothelial cell function, clotting and haemorrheological pathways. 4. The study results achieved with statins have obscured the role of fibrates as useful agents for reducing cardiovascular disease. Fibrates have a different mode of action to stains by reducing triglyceride-rich lipoprotein precursors and favourably altering LDL and HDL composition. 5. The practising clinician needs to consider the lipoprotein phenotype and to choose whether the ideal treatment is stain alone, fibrate alone or perhaps a combination.

Non-specialist management of tropical talipes

Talipes equinovarus (clubfoot) is a complex deformity which in the West is usually treated by trained orthopaedic surgeons. In developing countries, however, most clubfeet will need to be treated by medical officers lacking specialist training. We report one author's experience in treating clubfeet in a small, rural East African hospital and review the literature in order to assist other non-specialists in managing this difficult condition in the face of poverty and poor parental compliance.

Recurrent abdominal pain and Helicobacter pylori in a community-based sample of London children

Helicobacter pylori is accepted as an important factor in the pathogenesis of peptic ulcer disease. Infection is probably most commonly acquired in early life but there is still limited information on the prevalence or symptomatology of H. pylori infection in childhood. The aim of the present study was to establish the prevalence of H. pylori infection in a large sample of urban school children and to determine its relationship, if any, to a history of recurrent abdominal pain. Using a commercial ELISA significant levels of anti-H. pylori IgG antibody were detected in 107/640 (16.7%) of school children (M, 383; F, 257; mean age 9.15 years, range 4-13). No relationship was demonstrated between H. pylori seropositivity and a personal or family history of recurrent abdominal pain or the nature of the pain.

Different patterns of cytokine induction in cultures of respiratory syncytial (RS) virus-specific human TH cell lines following stimulation with RS virus and RS virus proteins

Human peripheral blood mononuclear cell (PBMC) proliferative responses to live respiratory syncytial (RS) virus, formalin-inactivated RS (Fl-RS) virus, RS virus F (fusion) protein, and RS virus G (attachment) protein were assessed. All donors responded to challenge with whole RS virus antigens and F and G proteins. F protein responses elicited higher levels of response than equivalent concentrations of G protein in nine out of ten adult RS-seropositive donors. Stimulation of PBMC induced low levels of interleukin 2 (IL-2), interferon gamma (IFN-gamma), IL-4, and IL-10 production. Human RS virus-specific T cell lines were generated from peripheral blood cultures following in vitro stimulation with RS virus antigens. All lines generated were shown to be MHC class II restricted. Characterisation of the lines was carried out by determining the levels of IL-2, IFN-gamma, IL-4, and IL-10 in culture supernatants. T cell lines enriched for RS virus-specific cells provided a more sensitive system than PBMC cultures for the detection of cytokines. The pattern of cytokine production varied for the individual lines, and the detection of TH1 and TH2 cytokines was dependent on the nature of the stimulating RS virus antigen. Live RS virus induced a TH1 pattern of cytokines (IL-2 and IFN-gamma), whereas FI-RS virus induced the production of both TH1 and TH2 cytokines. In addition, TH lines specific for individual RS virus proteins produced different cytokine profiles. F protein-specific lines generated TH1-type cytokines (IL-2 and IFN-gamma), whereas G protein-specific lines generated TH2-type cytokines (IL-4 and IL-10).

Increased expression of IL-1beta converting enzyme in hippocampus after ischemia: selective localization in microglia

Although the interleukin-1beta converting enzyme (ICE)/CED-3 family of proteases has been implicated recently in neuronal cell death in vitro and in ovo, the role of specific genes belonging to this family in cell death in the nervous system remains unknown. To address this question, we examined the in vivo expression of one of these genes, Ice, after global forebrain ischemia in gerbils. Using RT-PCR and Western immunoblot techniques, we detected an increase in the mRNA and protein expression of ICE in hippocampus during a period of 4 d after ischemia. Chromatin condensation was observed in CA1 neurons within 2 d after ischemia. Internucleosomal DNA fragmentation and apoptotic bodies were observed between 3 and 4 d after ischemia, a period during which CA1 neuronal death is maximal. In nonischemic brains, ICE-like immunoreactivity was relatively low in CA1 pyramidal neurons but high in scattered hippocampal interneurons. After ischemia, ICE-like immunoreactivity was not altered in these neurons. ICE-like immunoreactivity, however, was observed in microglial cells in the regions adjacent to the CA1 layer as early as 2 d after ischemic insult. The increase in ICE-like immunoreactivity was robust at 4 d after ischemia, a period that correlates with the DNA fragmentation observed in hippocampal homogenates of ischemic brains. These results provide the first evidence for the localization and induction of ICE expression in vivo after ischemia and suggest an indirect role for ICE in ischemic damage through mediation of an inflammatory response.

Mental health and adequacy of social support: a four-wave panel study

LISREL analyses with manifest variables were used to examine the causal relationship between mental health and adequacy of social integration and of attachment, measured at four consecutive waves each four months apart, in a representative sample of 225 adult residents in Canberra. Mental health was assessed with the 30-item General Health Questionnaire. The analyses suggest that while there is no temporal relationship between adequacy of attachment and mental health, adequacy of social integration is influenced by earlier mental health. The temporal relationship between adequacy of attachment and adequacy of social integration appears to be reciprocal.

Overexpression of p53 protein and its significance for recurrent progressive bladder tumours

OBJECTIVE

To determine the prognostic value of the overexpression of p53 protein as determined by immunohistochemistry in recurrent progressive transitional cell carcinomas of the bladder.

PATIENTS AND METHODS

A total of 222 tumours from 86 patients with recurrent disease, 20 from patients with no evidence of recurrence after resection of initial tumour and 11 normal bladder (controls) were investigated. Using a microwave technique to expose antigens, formalin-fixed sections were immunohistochemically stained for p53 using a polyclonal antiserum. Two independent observers scored the sections for evidence of overexpression of p53.

RESULTS

Of 86 patients with recurrent disease, 51 demonstrated overexpression of p53 protein, as did six of 20 patients with non-recurrent disease. Overexpression was not linked to recurrence (P = 0.5) but was related to worsening histological stage (P < 0.01) and increasing grade (P < 0.01). Regression analysis showed that overexpression of p53 for the primary tumour was not of predictive prognostic value for death from bladder cancer, time to progression or time to recurrence. Tumour grade was the only variable of prognostic value in all the statistical models. Patients with overexpression of p53 showed no reduction in overall survival.

CONCLUSION

These findings suggest that overexpression of p53, as determined immunohistochemically, appears to have no predictive prognostic value over stage and grade in bladder tumours.

Dynamics of human replication protein A subunit distribution and partitioning in the cell cycle

Human replication protein A (RPA) is a three-sub-unit protein complex involved in DNA replication, repair, and recombination. To gain insight into the dynamics of subunit assembly, we examined the subcellular distribution of RPA subunits (p70, p34, and p11) during the cell cycle. All three subunits colocalized in G1 and S phases, showing a diffuse nuclear distribution in G1 but a dot-like nuclear pattern in S phase. During S phase, the subunits showed a pattern reminiscent of the replication granules/factories described by others as sites of replication machinery. In meta-phase, p70 preferentially associated with the spindle poles, p34 was found on chromosomes, and p11 remained in the cytoplasm. In telophase, p70 and p34 appeared in the forming daughter nuclei; p11 remained in the cytoplasm until G1. Among the three subunits only p34 was associated with the nuclear matrix and this association persisted throughout the cell cycle. We conclude that (i) RPA complex assembly is differentially regulated, (ii) the replication machinery may be anchored to the nuclear matrix, and (iii) RPA subunits partition during mitosis and sort into daughter nuclei by different routes.

Extracorporeal methods of vascular control for difficult IVC procedures

Surgical procedures in the juxtaheptic and intrapericardial inferior vena cava (IVC) are difficult because of the complexity of achieving vascular control in the area. We describe 10 patients with a variety of pathologies in this region who underwent venovenous bypass (VVB) or cardiopulmonary bypass with hypothermic circulatory arrest (CBCA). Renal cell carcinoma with IVC extension was present in three patients (with tumor extension into the right atrium in two), adrenal adenocarcinoma in one, septic IVC thrombus in one, and blunt IVC/hepatic trauma in five. Those patients without atrial involvement underwent VVB with a mean bypass time of 40 minutes (range 12-144). Those patients with tumor extension into the right atrium underwent CBCA with systemic hypothermia to 18(0)C, total body exsanguination for a bloodless field, and removal of the tumor by cavotomy and right atriotomy. The mean bypass, aortic cross-clamp, and circulatory arrest times were 152, 92, and 36 minutes, respectively. Eight of the 10 patients did well and went home within 4 weeks of surgery. Two patients died, one from metabolic sequelae of exsanguinating IVC injury (VVB) and one from sepsis 2 weeks postoperatively (CBCA).

Sensitivity of cell lines to mitomycin C

OBJECTIVES

To determine the effect of pH on the cytotoxicity of mitomycin C on a wide range of established cell lines.

MATERIALS AND METHODS

Cultures of three human tumour cell lines, including two bladder carcinomas and one renal adenocarcinoma, and two mouse cell lines were treated with mitomycin C (concentration range 320 pM-50 microM) at a range of pH (5.8-7.8) for 2 h. The cytotoxicity of mitomycin C over this range was determined using a tetrazolium-dye-based microtitration assay.

RESULTS

The cytotoxicity of mitomycin C was significantly greater (confidence level > or = 95%) in acidic conditions (pH 5.8-6.0) than in neutral to alkaline pH (7.2-7.8) for three of the five cell lines. The same trend, although less marked, also occurred in the other two cell lines.

CONCLUSION

The cytotoxicity of mitomycin C was greater under acidic conditions for all these cell lines confirming that the activity of mitomycin C depends on pH and suggesting that the pH of the vehicle used for intravesical chemotherapy may be an important factor in the successful treatment of bladder carcinomas. The modification of pH by urine may explain some of the variation in success rates among patients treated intravesically with mitomycin C.

Activity levels and cognitive functioning in an elderly community sample

The influence of self-reported and informant-reported activity levels on Crystallized Intelligence, Fluid Intelligence, Memory and the Mini-Mental State Examination was investigated in a sample of 858 community-dwelling elderly subjects. Both self-reported and informant-reported activity levels explained variance beyond that accounted for by sex, sensory functioning, activities of daily living, medical conditions, current health problems and education. Age accounted for additional variance once activity and the other contextual variables were entered. Interaction effects indicated that inactivity was associated with poorer performance on fluid intelligence in older rather than younger elderly subjects and that inactivity was predictive of poor crystallized intelligence at younger ages. Higher informant-rated activity levels moderated the effects of education, so that higher activity offset effects associated with low education on memory tasks. The mount of variance explained by activity levels was modest.

Modified venovenous bypass technique for resection of renal and adrenal carcinomas with involvement of the inferior vena cava

Peripheric tumours with extension into the inferior vena cava pose difficult management problems. Venovenous bypass using a centrifugal pump to decompress the inferior vena cava may be useful adjunct during vascular isolation of the tumour. We have modified the technique by adding portal decompression to avoid visceral accumulation of toxic metabolites. We have used this technique in two patients who had intracaval extension of tumours, one renal and one adrenal carcinoma.

Televised violence: a Japanese, Spanish, and American comparison

In Japan, Spain, and the USA during one week acts of violence (verbal and nonverbal) were rated on the Index of Television Violence by 3 raters in each country. In all three countries televised violence was more likely depicted in interpersonal conflict than against property. Fewer scenes of physical or fatal injury appeared in Japan than in the other two countries. Other observations were made. Replication is urged.

Detection of new mutations in six out of 10 Swiss HNPCC families by genomic sequencing of the hMSH2 and hMLH1 genes

The cancer predisposition in most HNPCC families is believed to be associated with mutations in the human mismatch repair gene homologues hMSH2 and hMLH1. We searched for mutations in our collection of 10 Swiss HNPCC families by sequencing the exons and exon/intron boundaries of the hMSH2 and hMLH1 genes. In four families we found different mutations which are expected to lead to protein truncations of either the hMSH2 or the hMLH1 proteins owing to premature in frame stop codons or splice defects. In two more families we detected mutations leading to an amino acid deletion and an amino acid substitution in an evolutionary conserved residues respectively. None of these mutations has been reported in other families, which is consistent with the notion that HNPCC associated hMSH2 and hMLH1 mutations are heterogeneous and there is no striking founder effect in the Swiss population. Whenever this could be investigated, the presence of the mutations was confirmed in other family members who showed manifestations of HNPCC. Interestingly, an obligate carrier in one of the families developed a brain tumour at the age of 29, histologically verified as a glioblastoma multiforme, which was recently linked to HNPCC in the context of Turcot's syndrome.

Recurrent hemarthrosis after total knee arthroplasty

Thirty patients who developed recurrent hemarthrosis after total knee arthroplasty were followed for an average of 27.9 months. The average interval between implantation of the prosthesis and the first bleed was 24.2 months. Nine knees responded to conservative care alone. The remaining 21 knees continued to have recurrent bleeds requiring surgical intervention. Open synovectomy was performed in 15 knees and seemed to be curative in 14 (93%). Forty-three percent of the surgically treated knees were noted to have entrapment of proliferative synovial tissue or the fat pad between prosthetic components as the cause of the recurrent bleeds. Consistent histologic findings included focal synovial hyperplasia and significant hemosiderin deposition. Although similar, these changes should not be confused with those of pigmented villonodular synovitis.

Factors associated with the wish to die in elderly people

This study aimed to determine the prevalence of the wish to die in elderly people and investigate the factors associated with it, in particular, whether factors other than depression contribute to the wish to die. Data were obtained from an Australian epidemiological survey of people aged 70 or more. Survey participants were asked whether, in the last two weeks, they had felt that they wanted to die and, if so, if they had had such thoughts repeatedly. Three classes of possible risk factors were investigated: sociodemographic factors (age, sex, marital status), mental health (depression, cognitive impairment), and physical health (poor self-rated health, disability, pain, sensory impairment, and living in a nursing home or hostel). Only 21 of 923 elderly persons reported repeatedly having had a wish to die during the previous two weeks. Although the wish to die was associated with depression, there were several other factors also associated with it independently of depression: not being married, poor self-rated health, disability, pain, hearing impairment, visual impairment, living in a nursing home or hostel. A small minority expressed the wish to die but had a normal mood state. It was concluded that the wish to die is associated with several factors in addition to depression and may be present in individuals with few depressive symptoms. There is a need to investigate whether factors associated with the wish to die are treatable and whether this can restore the desire to live.