Multiple sclerosis in sibling pairs: an analysis of 250 families

OBJECTIVES

To assess the potential contribution of genetic factors to clinical phenotype in multiple sclerosis.

METHODS

Using a cohort of 262 pairs of coaffected siblings from 250 families with multiple sclerosis, intersibling concordance analysis was used to explore underlying genetic mechanisms in disease pathogenesis by assessing parameters of disease course, clinical presentation, age and year of onset, and measures of disability and handicap.

RESULTS

Adjusted intraclass correlation coefficients were not significant for either age of onset or for year of first symptom. One third of sibling pairs were concordant for presenting symptom (81/262), a result that was non-significant. However, course type was identical in 50% of the sibling pairs (kappa=0.17 (95% confidence interval (95% CI) 0.08 to 0.26)) indicating a significant result. Severity of the disease at assessment, using the Kurtzke and CAMBS scales, demonstrated that whereas there was no agreement for relapse rate in the previous year within the sibship, there was significant concordance for measures of disability (kappa=0.11 (95% CI 0.04 to 0.19)), progression (kappa=0.09 (95% CI 0.01 to 0.18)) and handicap (kappa=0.08 (95% CI 0.02 to 0.14)).

CONCLUSIONS

Within a sibship, the clinical presentation tends to be different. However, once established, concordance is more likely to be seen for the ultimate course, leading in the end to similar disability and handicap scores. These results are consistent with the hypothesis that genes influence both disease susceptibility and evolution in multiple sclerosis.

Potassium bis(4,5-dimercapto-1,3-dithiole-2-thionato)nickelate 1,4,7,10,13,16-hexaoxa-2,3:11,12-dibenzocyclooctadeca-2,11-diene propanone solvate

In the title compound, K[Ni(C(3)S(5))(2)] x C(20)H(24)O(6).C(3)H(6)O, K(+) is incorporated in the cavity of the 1,4,7,10,13,16-hexaoxa-2,3:11,12-dibenzocyclooctadeca-2,11-diene (DB18c6) molecule and is coordinated by the six DB18c6 O atoms and the propanone O atom. Two [K(+)(DB18c6)[(CH(3))(2)CO]] units form a dimer which is aligned in a one-dimensional manner along the a axis through a face-to-face interaction between the benzene rings of neighboring DB18c6 molecules. [Ni(dmit)(2)](-) anions are also aligned along the a axis through side-by-side S.S interactions.

Effects of ras and von Hippel-Lindau (VHL) gene mutations on hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, and vascular endothelial growth factor expression and their regulation by the phosphatidylinositol 3'-kinase/Akt signaling pathway

Many oncogenes induce expression of vascular endothelial growth factor (VEGF), a key factor in tumor angiogenesis. Phosphatidylinositol 3'-kinase (PI3K)/Akt is a common signaling pathway for oncogenes and tumor suppressor genes and is involved in VEGF regulation. Because hypoxia is a major stimulus for VEGF production, we examined the effects of LY294002, a selective PI3K inhibitor, on hypoxia-inducible factor (HIF)-1alpha and HIF-2alpha expression and on endogenous VEGF responses to hypoxia. A panel of breast cancer cell lines reflecting the different genetic changes occurring in human breast cancer was analyzed. LY294002 inhibited HIF-1alpha induction and phosphorylation under hypoxia. However, HIF-2alpha expression was not affected. Basal and hypoxia-inducible VEGF expression was reduced at both mRNA and protein levels by 50%. V12-ras overexpression resulted in an increase in hypoxia-induced HIF-1alpha and HIF-2alpha expression. This effect was blocked by PI3K inhibitor, demonstrating one mechanism for ras synergy with hypoxia-mediated induction of genes. The decreased HIF-1alpha expression was not dependent on VHL interaction because a renal carcinoma cell line with VHL mutation and constitutive high HIF-1alpha expression also showed down-regulation of HIF-1alpha after treatment with LY294002. These results have implications for the use of PI3K inhibitors to inhibit synergistic effects of hypoxia with a wide range of common oncogenes.

Randomised controlled trial of tailored strategies to implement guidelines for the management of patients with depression in general practice

BACKGROUND

Various methods are available for implementing change in the clinical behaviour of general practitioners (GPs). Although passive dissemination of information is generally ineffective, other methods can be variably effective. Few studies have investigated the impact of tailored methods.

AIM

To determine whether methods tailored to overcome obstacles to change using psychological theories are more effective than dissemination alone in the implementation of guidelines for depression among GPs.

DESIGN OF STUDY

Randomised controlled trial.

SETTING

Sixty general practices in England; 30 GPs in the control group, 34 in the intervention group.

METHOD

Practitioners identified patients presenting with depression before and after the implementation of guidelines (control group n = 192 in the first data collection, n = 181 in the second; intervention group n = 210 in the first data collection and n = 197 in the second). The main outcome measures were: record of adherence to guideline recommendations in clinical records; proportion of patients with Beck Depression Inventory (BDI) score less than 11 at 16 weeks after diagnosis.

RESULTS

In comparison with the control group, in the group of GPs receiving tailored implementation, there were increases in the proportions of patients assessed for suicide risk. In the intervention group, the proportion of patients with BDI scores of less than 11 at 16 weeks increased.

CONCLUSION

Obstacles to implementation can be identified and strategies tailored to address them. The findings indicate a new approach for research to understand and develop methods of implementation.

Twenty-four hours of mild hypothermia in unsedated newborn pigs starting after a severe global hypoxic-ischemic insult is not neuroprotective

Three to 12 h of mild hypothermia (HT) starting after hypoxia-ischemia is neuroprotective in piglets that are anesthetized during HT. Newborn infants suffering from neonatal encephalopathy often ventilate spontaneously and are not necessarily sedated. We aimed to test whether mild posthypoxic HT lasting 24 h was neuroprotective if the animals were not sedated. Thirty-nine piglets (median weight 1.6 kg, range 0.8-2.2 kg; median age 24 h, range 7-48 h) were anesthetized and ventilated and subjected to a 45-min hypoxic (FiO(2) approximately 6%) global insult (n = 36) or sham hypoxia (n = 3). On reoxygenation, 18 were maintained normothermic (NT, 39.0 degrees C) for 72 h, and 21 were cooled from 39 (NT) to 35 degrees C (HT) for the first 24 h before NT was resumed (18 experimental, three sham hypoxia). Cardiovascular parameters and intermittent EEG were documented throughout. The brain was perfusion fixed for neuropathology and five main areas examined using light microscopy. The insult severity (duration in minutes of EEG amplitude < 7 microV) was similar in the NT and HT groups, mean +/- SD (28 +/- 7.2 versus 27 +/- 8.6 min), as was the mean FiO(2) (5.9 +/- 0.7 versus 5.8 +/- 0.8%) during the insult. Six NT and seven HT piglets developed posthypoxic seizures that lasted 29 and 30% of the time, respectively. The distribution and degree of injury (0.0-4.0, normal-maximal damage) within the brain (hippocampus, cortex/white matter, cerebellum, basal ganglia, thalamus) were similar in the NT and HT groups (overall score, mean +/- SD, 2.3 +/- 1.5 versus 2.4 +/- 1.3) as was the EEG background amplitude at 3 h (13 +/- 3.5 versus 10 +/- 3.3 microV). The HT animals shivered and were more active. The sham control group (n = 3) shivered but had normal physiology and neuropathology. Plasma cortisol was significantly higher in the HT group during the HT period, 766 +/- 277 versus 244 +/- 144 microM at 24 h. Mild postinsult HT for 24 h was not neuroprotective in unsedated piglets and did not reduce the number of animals that developed posthypoxic seizures. Cortisol reached 3 times the NT value at the end of HT. We speculate that the stress of shivering and feeling cold interfered with the previously shown neuroprotective effect of HT. Research on the appropriateness of sedation during clinical HT is urgent.

Effect of IL-5, glucocorticoid, and Fas ligation on Bcl-2 homologue expression and caspase activation in circulating human eosinophils

IL-5 is a potent eosinophil viability-enhancing factor that has been strongly implicated in the pathogenesis of IgE-mediated inflammation in vivo. Recently published data have suggested that IL-5 (and related cytokines) may act by altering the expression of the anti-apoptotic regulator Bcl-2 or its homologues, but this is controversial. The behaviour of the recently described pro-apoptotic cysteine proteases (caspases) in eosinophils after IL-5 treatment has not been explored. We examined the effect of IL-5 on the expression of four major Bcl-2 homologues, as well as on the expression/activation of key members of the caspase cell death cascade in cultured circulating human eosinophils. The effect of relevant inducers of eosinophil apoptosis (glucocorticoid and Fas ligation) on these regulatory proteins was also examined. We observed baseline expression of the anti-apoptotic Mcl-1 and pro-apoptotic Bax proteins in immunoblots of eosinophil lysates, but not Bcl-x, Bcl-2. IL-5 treatment had the effect of maintaining this basal level of expression over time without altering the balance of Bcl-2 homologues. The (upstream) caspase 8 and (downstream) caspase 3 proenzymes were detected in eosinophils at baseline, and were processed during spontaneous and stimulated eosinophil death. IL-5 completely blocked caspase processing in spontaneous and dexamethasone-induced cell death, and significantly slowed processing during Fas ligation. Our data do not support the theory that IL-5 acts by altering the balance of anti-apoptotic and pro-apoptotic Bcl-2 homologues, but suggest that it may act by regulating activation of the caspase cell death cascade.

Thyroglossal duct remnants

Thyroglossal duct remnants presenting as a lump in the neck are usually called thyroglossal cysts. Meticulous dissection of the cyst and duct, along with the body of the hyoid bone (Sistrunk's operation) is necessary to avoid recurrence. The authors have reviewed the histology of 61 consecutive specimens diagnosed preoperatively as thyroglossal cysts and have found that a true cyst exists in only 46 per cent of cases.

Protection of mice against challenge with foot and mouth disease virus (FMDV) by immunization with foliar extracts from plants infected with recombinant tobacco mosaic virus expressing the FMDV structural protein VP1

A tobacco mosaic virus (TMV)-based vector has been used to express in plants the complete open reading frame coding for VP1, the major immunogenic protein of foot and mouth disease virus (FMDV). In vitro RNA transcripts were inoculated into Nicotiana benthamiana plants and detectable amounts of recombinant VP1 were identified by Western blot as soon as 4 days postinfection. Foliar extracts prepared from infected leaves were injected intraperitoneally into mice and all of the immunized animals developed a specific antibody response to both the complete virus particle and the major immunogenic region as determined by ELISA and Western blot analysis. Most importantly, all immunized mice developed a protective immune response against experimental challenge with virulent FMDV. To our knowledge, this is the first report showing the expression of a complete open reading frame of an antigenic foreign protein in plants, using a recombinant plant virus, in sufficient quantity to permit use of the crude plant extract as an experimental immunogen to protect animals against virus challenge.

Experience using radio frequency laptops to access the electronic medical record in exam rooms

Kaiser Permanente, Northwest, evaluated the use of laptop computers to access our existing comprehensive Electronic Medical Record in exam rooms via a wireless radiofrequency (RF) network. Eleven of 22 clinicians who were offered the laptops successfully adopted their use in the exam room. These clinicians were able to increase their exam room time with the patient by almost 4 minutes (25%), apparently without lengthening their overall work day. Patient response to exam room computing was overwhelmingly positive. The RF network response time was similar to the hardwired network. Problems cited by some laptop users and many of the eleven non-adopters included battery issues, different equipment layout and function, and inadequate training. IT support needs for the RF laptops were two to four times greater than for hardwired desktops. Addressing the reliability and training issues should increase clinician acceptance, making a successful general roll-out for exam room computing more likely.

Functional characterization of the protease of human endogenous retrovirus, K10: can it complement HIV-1 protease?

To investigate the biochemical properties of the protease encoded by the human endogenous retrovirus, K10 (HERV-K), 213 amino acids of the 3'-end of the HERV-K protease (PR) open reading frame were expressed in Escherichia coli. Autocatalytic cleavage of the expressed polypeptide resulted in an 18.2 kDa protein which was shown to be proteolytically active against a fluorogenic peptide used as a substrate for HIV-1 protease. On the basis of sequence homology and molecular modeling, the 106 N-terminal amino acids of HERV-K PR were predicted to comprise a retroviral protease core domain. An 11.6 kDa protein corresponding to this region was expressed and shown to be a fully functional enzyme. The 11.6 kDa domain of HERV-K PR is unusually stable over a wide pH range, exhibits optimal catalytic activity between pH 4.0 and 5.0, and exists as a dimer at pH 7.0 with a Kd of 50 microM. Like HIV-1 PR, the HERV-K PR core domain is activated by high salt concentrations and processes HIV-1 matrix-capsid polyprotein at the authentic HIV-1 PR recognition site. However, both the 18.2 and 11.6 kDa forms of HERV-K PR were highly resistant to a number of clinically useful HIV-1 PR inhibitors, including ritonavir, indinavir, and saquinavir. This raises the possibility that HERV-K PR may complement HIV-1 PR during infection, and could have implications for protease inhibitor therapy and drug resistance.

Introducing a quality improvement programme to primary healthcare teams

OBJECTIVES

To evaluate a programme in which quality improvement was facilitated, based on principles of total quality management, in primary healthcare teams, and to determine its feasibility, acceptability, effectiveness, and the duration of its effect.

METHOD

Primary healthcare teams in Leicestershire (n = 147) were invited to take part in the facilitated programme. The programme comprised seven team meetings, led by a researcher, plus up to two facilitated meetings of quality improvement subgroups, appointed by each team to consider specific quality issues.

OUTCOME MEASURES

To assess the effect and feasibility of the programme on improving the quality of care provided, the individual quality improvement projects undertaken by the teams were documented and opportunities for improvement were noted at each session by the facilitator. The programme's acceptability was assessed with questionnaires issued in the final session to each participant. To assess the long term impact on teams, interviews with team members were conducted 3 years after the programme ended.

RESULTS

10 of the 27 teams that initially expressed interest in the programme agreed to take part, and six started the programme. Of these, five completed their quality improvement projects and used several different quality tools, and three completed all seven sessions of the programme. The programme was assessed as appropriate and acceptable by the participants. Three years later, the changes made during the programme were still in place in three of the six teams. Four teams had decided to undertake the local quality monitoring programme, resourced and supported by the Health Authority.

CONCLUSIONS

The facilitated programme was feasible, acceptable, and effective for a few primary healthcare teams. The outcomes of the programme can be sustained. Research is needed on the characteristics of teams likely to be successful in the introduction and maintenance of quality improvement programmes.

The genetics of multiple sclerosis: principles, background and updated results of the United Kingdom systematic genome screen

Genetic susceptibility to multiple sclerosis is implicated on the basis of classical family studies and phenotype analyses. The only reproducible legacy from the candidate gene approach has been the discovery of population associations with alleles of the major histocompatibility complex. Systematic genome scanning has since been applied using a panel of anonymous markers to identify areas of linkage in co-affected siblings. Here, we describe the principles of genome screening and update the UK survey of multiple sclerosis. This identified 20 regions of potential interest, but in none was there unequivocal linkage. In theory, attempting to replicate these findings in a second set of sibling pair families is the most appropriate way to distinguish true from false positives, but unfortunately the number of families required to do this reliably is prohibitively large. We used three approaches to increase the definition achieved by the screen: (i) the number of sibling pairs typed in an identified region of potential linkage was extended; (ii) the information extraction was increased in an identified region; and (iii) a search was made for missed regions of potential linkage. Each of these approaches has considerable limitations. A chromosome-by-chromosome account is given to direct future searches. Although an additional marker placed distal to the 'hit' on chromosome 14q increased linkage in this area, and typing extra sibling pairs increased linkage on chromosomes 6p and 17q, evidence for linkage was more commonly reduced and no additional regions of interest were found. A further refinement of the genome screen was undertaken by conditioning for the presence of HLA-DR15. This produced a surprising degree of segregation among the regions of interest, which divided into two distinct groups depending on DR15 sharing: the DR15-sharing cohort comprised loci on chromosomal areas 1p, 17q and X; and the DR15-non-sharing cohort was made up of loci on 1cen, 3p, 7p, 14q and 22q. This result further highlights the genetic complexity of multiple sclerosis. What can now be inferred is that a gene of major effect is excluded from 95% of the genome and one with a moderate role from 65%, whereas genes which make a very small biological contribution cannot be discounted from any region. The available results suggest that multiple sclerosis depends on independent or epistatic effects of several genes each with small individual effects, rather than a very few genes of major biological importance.

Targeting hypoxia with a new generation of indolequinones

The indolequinone class of bioreductive alkylating agents has been developed to effectively target the hypoxic cell population of the tumour. The mechanism of activation of these prodrugs relies initially on the reduction of the p-quinonoid moiety utilizing reductive enzymes to form electrophilic sites which can be attacked by DNA to promote cell kill. Minor structural changes of the indole 'nucleus' may result in substantial favourable pharmacological and physiological changes. Investigation of the mode of action of these compounds has resulted in the use of novel indolequinones as 'trigger' molecules that can efficiently release secondary agents into the hypoxic site of action.

11Beta-hydroxysteroid dehydrogenase, mineralocorticoid receptor, and thiazide-sensitive Na-Cl cotransporter expression by distal tubules

Mineralocorticoid hormones regulate salt transport along the distal nephron by binding to intracellular receptors and activating gene transcription. Previous experiments showed that systemic aldosterone infusions stimulate thiazide-sensitive Na and Cl transport by distal convoluted tubule (DCT) cells; this effect could have been direct or secondary to systemic hormonal effects. Aldosterone target tissues express both mineralocorticoid receptors and the metabolic enzyme 11beta-hydroxysteroid dehydrogenase type 2. Mineralocorticoid receptors have been localized to the DCT in some experiments, but not in others. Expression of 11beta-hydroxysteroid dehydrogenase type 2 by DCT cells has not been investigated. The present experiments were designed to test the hypothesis that rat DCT cells are targets of aldosterone action. Patterns of mineralocorticoid receptor, 11beta-hydroxysteroid dehydrogenase, thiazide-sensitive Na-Cl cotransporter, and Na/Ca exchanger expression along the distal tubule were examined. A polyclonal antibody was generated to localize the thiazide-sensitive Na-Cl cotransporter. Thiazide-sensitive Na-Cl cotransporter and 11beta-hydroxysteroid dehydrogenase expression were examined using both in situ hybridization and immunocytochemistry; Na/Ca exchanger and mineralocorticoid receptor expression were examined by immunocytochemistry. The results indicate that 11beta-hydroxysteroid dehydrogenase is expressed by DCT cells, as well as connecting tubule cells and principal cells of the collecting duct; expression levels are low near the junction with the thick ascending limb and rise near the transition to the connecting tubule. Mineralocorticoid receptors are expressed by DCT cells, as well as along the thick ascending limb, connecting tubule, and collecting duct. The results indicate that components of the mineralocorticoid receptor system are expressed by DCT cells, suggesting that these cells are targets of aldosterone action.

Indolequinone antitumor agents: reductive activation and elimination from (5-methoxy-1-methyl-4,7-dioxoindol-3-yl)methyl derivatives and hypoxia-selective cytotoxicity in vitro

A series of indolequinones bearing a variety of leaving groups at the (indol-3-yl)methyl position was synthesized by functionalization of the corresponding 3-(hydroxymethyl)indolequinone, and the resulting compounds were evaluated in vitro as bioreductively activated cytotoxins. The elimination of a range of functional groups-carboxylate, phenol, and thiol-was demonstrated upon reductive activation under both chemical and quantitative radiolytic conditions. Only those compounds which eliminated such groups under both sets of conditions exhibited significant hypoxia selectivity, with anoxic:oxic toxicity ratios in the range 10-200. With the exception of the 3-hydroxymethyl derivative, radiolytic generation of semiquinone radicals and HPLC analysis indicated that efficient elimination of the leaving group occurred following one-electron reduction of the parent compound. The active species in leaving group elimination was predominantly the hydroquinone rather than the semiquinone radical. The resulting iminium derivative acted as an alkylating agent and was efficiently trapped by added thiol following chemical reduction and by either water or 2-propanol following radiolytic reduction. A chain reaction in the radical-initiated reduction of these indolequinones (not seen in a simpler benzoquinone) in the presence of a hydrogen donor (2-propanol) was observed. Compounds that were unsubstituted at C-2 were found to be up to 300 times more potent as cytotoxins than their 2-alkyl-substituted analogues in V79-379A cells, but with lower hypoxic cytotoxicity ratios.

5-substituted analogues of 3-hydroxymethyl-5-aziridinyl-1-methyl-2-[1H-indole-4,7-dione]prop-2-en- 1-ol (EO9, NSC 382459) and their regioisomers as hypoxia-selective agents: structure-cytotoxicity in vitro

A series of regioisomeric analogues of 3-hydroxymethyl-5-aziridinyl-1-methyl-2-[1H-indole-4,7-dione]prop-2-en-1 -ol (EO9, NSC 382459) with the hydroxymethyl and hydroxypropenyl substituents situated at either the 2- or the 3-position of the indole ring were synthesized. The compound lacking the 2-hydroxypropenyl substituent (31) had similar properties to EO9 under both aerobic and hypoxic conditions against V79 cells and was more potent against a human tumour cell line (A549) than EO9. It was reduced by human DT-diaphorase (DTD) at more than double the rate of EO9, thus implicating the importance of the enzyme activation step. Compound 16 (lacking the 3-hydroxymethyl substituent) was a better substrate for human DTD than EO9, yet exhibited lesser toxicity under both aerobic and hypoxic conditions. The toxicity generated by 16 was attributed to the 5-aziridinyl moiety and suggests a greater contribution from the 3-substituent over the 2-substituent. The toxicity of EO9 was attributed to a combination of the aziridinyl group and the leaving group properties of the 3-hydroxymethyl substituent. In general, compounds with a 5-methylaziridinyl moiety, such as EO8, exhibited substantially better hypoxia-selectivity due to much slower reduction by DTD (20-fold), thus reducing aerobic potency. All compounds had similar electron affinities, as indicated by their one-electron reduction potentials.