Relationship between dynamic balance and self-reported handicap in patients who have unilateral peripheral vestibular loss.

OBJECTIVE: The purpose of this study was to investigate whether Dizziness Handicap Inventory (DHI) score is related to postural performance as assessed by dynamic posturography. STUDY DESIGN: Retrospective study. SETTING: Outpatient in a tertiary referral center. PATIENTS: Ninety-two complete unilateral vestibular loss patients, categorized into 3 groups according to the postlesion stage: 1 to 2 months (n = 32; age, 47.6 +/- 10.7 yr), 4 to 7 months (n= 23; 47.1 +/- 8.37 yr), and 1 year and older (n = 37; 49.2 +/- 9.5 yr). MAIN OUTCOME MEASURES: Dizziness Handicap Inventory and dynamic balance measured with a seesaw platform moving either in the anterior-posterior or in the mediolateral direction. RESULTS: The mean DHI score was 25.8 +/- 18.7 and the range was 0 to 68. Dizziness Handicap Inventory scores did not differ significantly between the different unilateral vestibular loss groups studied. No difference was detected between the groups for the 3 subscores (emotional, functional, and physical), except that the older-than-1-year group had a significantly higher physical score than the 2 others. No correlation was found between DHI scores and postural indicators for either direction of the platform. However, patients unable to maintain balance when the seesaw platform moved in the mediolateral direction had significantly higher DHI scores than those who did not fall. CONCLUSION: Even if they are not directly related, we suggest that DHI and dynamic posturography are complementary approaches for appreciating the vestibular compensation process and are thus useful for postoperative counseling for vestibular loss patients.     

The effect of raised pH on pacemaker activity and ionic currents in cardiac purkinje fibers

1. Cardiac Purkinje fibers exposed to alkaline solutions (pH 8 to 9.5) show an increase in rate of diastolic depolarization, eventually resulting in induction of spontaneous activity or an increase of the spontaneous firing rate.
2. The voltage-clamp analysis of the transmembrane currents in pH 9–9.5 shows: i) a shift in the depolarizing direction of the activation (s∞) and time constants (τ _s ) curve of the \(i_{{\text{K}}_{\text{2}} }\) current, ii) a small increase in the maximal value of the fully activated \(i_{{\text{K}}_{\text{2}} }\) current, iii) no significant change of background current in the pacemaker region of membrane potentials.
3. The effect of NH₄Cl was studied as a means to vary intracellular pH. In the presence of Tris buffer the addition of 5 mM NH₄Cl resulted in i) a shift in the depolarizing direction and a decrease in slope of the activation curve of the \(i_{{\text{K}}_{\text{2}} }\) current, ii) a shift in the depolarizing direction of the time-constants curve together with an increase in the maximum value of τ _s , iii) an increase in the maximum value of the fully activated \(i_{{\text{K}}_{\text{2}} }\) current and a depolarizing shift of the reversal potential, similar to the effect of addition of K_c. In the presence of CO₂?HCO₃ buffer the addition of NH₄Cl had no significant effect on the kinetics of the \(i_{{\text{K}}_{\text{2}} }\) current. Since intracellular pH is only affected by NH₄Cl in the presence of Tris buffer, the results suggest that intracellular alkalinization is responsible for the change in \(i_{{\text{K}}_{\text{2}} }\) kinetics.
4. Based on the findings with NH₄Cl it is suggested that perfusion with Tris buffered alkaline solutions not only affects net negative surface charges on the outside but also and to a larger extent increases negative surface charges on the inside of the cell membrane.

     

A quality control program for mutation detection in KIT and PDGFRA in gastrointestinal stromal tumours

Background

Although most gastrointestinal stromal tumours (GIST) carry oncogenic mutations in KIT exons 9, 11, 13 and 17, or in platelet-derived growth factor receptor alpha (PDGFRA) exons 12, 14 and 18, around 10% of GIST are free of these mutations. Genotyping and accurate detection of KIT/PDGFRA mutations in GIST are becoming increasingly useful for clinicians in the management of the disease.

Method

To evaluate and improve laboratory practice in GIST mutation detection, we developed a mutational screening quality control program. Eleven laboratories were enrolled in this program and 50 DNA samples were analysed, each of them by four different laboratories, giving 200 mutational reports.

Results

In total, eight mutations were not detected by at least one laboratory. One false positive result was reported in one sample. Thus, the mean global rate of error with clinical implication based on 200 reports was 4.5%. Concerning specific polymorphisms detection, the rate varied from 0 to 100%, depending on the laboratory. The way mutations were reported was very heterogeneous, and some errors were detected.

Conclusion

This study demonstrated that such a program was necessary for laboratories to improve the quality of the analysis, because an error rate of 4.5% may have clinical consequences for the patient.     

Rectal duplications in children: two case reports and review of the literature

Duplications of the rectum are extremely rare, with only 60 cases reported in the world literature. We report two patients with cystic duplications of the rectum who underwent surgical intervention in our institution during the past 10 years. A 5-year-old white male presented with constipation and tenesmus as well as a 4-cm cystic mass that protruded from the anus when he strained to pass stool. Rectal examination and ultrasound suggested the clinical diagnosis of rectal duplication. Transanal submucosal resection of a 3-cm cystic mass adherent to the posterior rectal wall was carried out. Histologic examination revealed a rectal duplication containing zones of ciliated respiratory epithelium. The second patient, a 6-year-old white female, presented with a history of chronic constipation. A large, cystic presacral mass was detected by rectal examination and confirmed by CT scan. Complete submucosal resection of the cystic duplication was performed through a posterior trans-sacral approach. Histology revealed a rectal duplication lined by respiratory epithelium. Although duplications are generally lined by mucosa of the adjacent bowel, heterotopic mucosa, most commonly gastric or pancreatic, may be present. Rectal duplications with ectopic gastric mucosa have been previously described, but to our knowledge the presence of respiratory epithelium in a rectal duplication has never been reported. Complete resection of these lesions results in cure.Presented at the 21st Annual Meeting Canadian Association of Paediatric Surgeons Edmonton, Alberta, Canada September 21–23, 1989 Offprint requests to: A. L. Bensousson     

The use of primary total hip arthroplasty in university hospitals of the European Union

Current practice in primary total hip replacement was investigated by postal survey in 125 university hospitals of the European Union (EU). Most hospitals (78.4%) use a hip register and implant cemented as well as uncemented stems (72.0%) and cups (68.8%). In Scandinavian & Anglo-Saxon countries, 42.9% of the departments implant cemented stems in all their patients, and 16.7% implant cemented cups in all their patients. In these countries, modern cementing techniques are commonly used and therapeutic choices are strongly influenced by hip registers. In Southern Europe, cemented cups have been abandoned in 31.1% and modern cementing techniques are less common. Benelux & Germanic countries have a practice in between. Three cemented (Exeter, Charnley, Lubinus) and three uncemented stems (Zweymüller, ABG, Bi-contact) represent 41.9% and 25.3% of stem types in use. Most departments (70.4%) have adopted alternative bearings. Ceramic-ceramic and metal-metal are both used in almost half of the hospitals. Metal-polyethylene has been abandoned in 15.2%. These trends are taught to new generations of surgeons in the EU and could become common practice in a near future.     

Saphenous Vein Loop to Femoral Artery Arteriovenous Fistula: <Emphasis Type="SmallCaps">A P</Emphasis>ractical <Emphasis Type="SmallCaps">A</Emphasis>lternative

Secondary to central venous stenosis or thrombosis, alternate sites for permanent hemodialysis need to be explored. The authors experience with the greater saphenous vein to common femoral artery loop arteriovenous fistula (GSV-CFA AVF) is presented. A retrospective review was performed of 4 women and 3 men with a mean age of 52.7 (range, 44-68) years. The mean number of prior access procedures was 3.85 (range, 1-5). Duplex ultrasound showed the greater saphenous vein (GSV) to be at least 3 mm in diameter. Perioperatively, no acute occlusion or significant steal syndrome developed. Groin wound complications (57.1%) resolved with local wound care and selectively antibiotic administration. Six patients developed mild to moderate edema, which required knee-high compression stockings. The mean follow-up was 15 (range, 9-24) months. Mean primary patency was 7 months, primary assisted patency was 15 months, and secondary patency was 16 months. The fistula was functional for hemodialysis in 71.4% (5/7). All patients developed stenoses within the GSV loop, with a mean of 3.0 balloon angioplasties per fistula. Three secondary surgical procedures were performed (two pseudoaneurysm repairs, one vein patch angioplasty). The GSV did not increase significantly in diameter. Use of a GSV-CFA AVF for dialysis access has acceptable results for alternate-site hemodialysis access. Secondary procedures were common. Factors recognized to be important for success were an adequate-sized GSV preoperatively, positioning of the GSV loop, and patient body habitus.     

Predictive value of biological markers for hepatocellular carcinoma patients treated with orthotopic liver transplantation.

PURPOSE: To help stratify candidates with hepatocellular carcinoma (HCC) for orthotopic liver transplantation (OLT), biomarkers are needed that are capable of predicting recurrence of disease (ROD). We investigated the prognostic role in this setting of immunohistochemical markers reported previously to predict poor prognosis in HCC patients treated with resection. EXPERIMENTAL DESIGN: Eighty-three patients with HCC who underwent OLT between 1987 and 2001 with a minimum clinical follow up of 12 months were included in this retrospective study. We analyzed immunohistochemical expression of the adhesion molecules E-cadherin and beta-catenin (membrane/nuclear localization), MIB-1 proliferative index and the cyclin-dependent kinase inhibitor p27, alongside the main clinical-pathological variables. RESULTS: At univariate analysis, vascular thrombosis, high MIB-1 index, lower membrane expression of E-cadherin and beta-catenin, and nuclear beta-catenin localization were associated with ROD. At multivariate analysis, only MIB-1 index, low equal E-cadherin (with respect to non-neoplastic surrounding tissue), and nuclear beta-catenin appeared as independent predictors of ROD. The logistic regression analysis model indicated that detection of any one parameter was associated with at least 88% estimated risk of ROD (up to 99% for all three). CONCLUSIONS: We propose these three molecular parameters as an additional tool for rational selection of OLT candidates among HCC patients (stratification according to the risk of ROD might help provide a similar life expectancy for cirrhotic candidates with and without HCC).     

Central neurotensin receptor activation produces differential behavioral responses in Fischer and Lewis rats

Rationale Lewis (LEW) and Fischer (F344) rats exhibit marked differences in appetitive and consummatory responses to numerous drugs, including psychostimulants. Neurotensin (NT) produces psychostimulant-like actions, which sensitize with repeated exposure, and neuroleptic-like actions; effects that are dependent on the site of microinjection. The aim of the present experiments was to assess the behavioral sensitivity of these two strains of rats to NT receptor activation. Methods In expt 1, locomotor activity was assessed on alternate days following an ICV injection of NT, [d-Tyr¹¹]neurotensin (d-NT; 18 nmol/10 μl), or vehicle (days 1, 3, 5, and 7) in independent groups of LEW and F344 rats. On day 14, locomotor activity was assessed in all rats following an injection of d-amphetamine (1 mg/kg, IP). In expt 2, activity was assessed following injection into the ventral tegmental area of NT, or d-NT, (2.5 μg/hemisphere) or into the nucleus accumbens (2.5 and 5.0 μg/hemisphere). Results Repeated ICV injections of NT, or d-NT, produced differential behavioral effects in the two strains of rats on days 1–7; activity was initially suppressed in LEW, but less so in F344 rats, following NT. In F344, but not in LEW rats, d-NT produced a significant increase in activity. Neurotensin and d-NT sensitized LEW rats to amphetamine-induced ambulatory and non-ambulatory activity. Except for vertical activity, this effect was weaker or in the opposite direction in F344 rats. When injected into the ventral tegmental area, NT produced an increase in locomotor activity in both strains, an effect that was greater in F344 than LEW rats with d-NT. In the nucleus accumbens, NT marginally decreased activity in both strains, while d-NT produced a significant increase in F344 but not in LEW rats. Conclusions These results provide empirical evidence that endogenous NT neurotransmission within limbic circuitry differs in F344 and LEW rats.