Mid-term quality of life after gastric band removal and single-stage conversion to gastric bypass: a single-center cohort study

BACKGROUND

Revision surgeries in patients with failed gastric banding including band removal are increasingly necessary. However, long-term outcomes after band removal alone are unsatisfactory due to weight regain and limited improvement in quality of life. This study aimed to report mid-term quality of life outcomes after gastric band removal and single-stage conversion to Roux-en-Y gastric bypass.

METHODS

Data of 108 patients who underwent conversion surgery from 2011 to 2017 were extracted from a prospective database and retrospectively analyzed. During follow-up visits, physical and laboratory data as well as quality of life questionnaires were obtained.

RESULTS

Postoperative mean Moorehead score increased significantly after 1 year (1.62 ± 0.86, p < 0.001) and after 5 years (1.55 ± 0.84, p < 0.001) compared to baseline values (0.72 ± 1.1). The mean follow-up time was 53 months. Moorehead scores at 1, 2, and 5 years postoperative were available in 75% (n = 81), 71% (n = 77), and 42% (n = 45) of cases, respectively. Mixed ANOVA analysis showed a significantly superior increase in Moorehead score in males (p = 0.024). No other significant predictors were identified. Lasting BMI reduction (- 4.6 to 33.0 ± 6.7 kg/m², p < 0.001) and weight loss (- 12.9% (- 13.6 kg), p < 0.001) 5 years after conversion surgery were seen. Postoperative complications occurred in 35% (n = 38) of patients with a re-operation rate of 30.5% (n = 33).

CONCLUSION

The current study shows that band removal with single-stage gastric bypass in patients with failed gastric banding leads to a lasting improvement in quality of life and may be the rescue procedure of choice in this setting.

Long-term quality of life after gastric band removal and concomitant conversion to gastric bypass: A single center cohort study

Objective

To report long-term quality of life and determine predictors for improved quality of life after gastric band removal and concomitant conversion to Roux-en-Y gastric bypass.

Methods

Clinical data of all patients who underwent conversion surgery from 2011 to 2017 were extracted from a prospectively maintained bariatric database and retrospectively analysed. During scheduled follow-up visits at 1, 6, 12, 24, 36, 48, and 60 months after surgery, physical and laboratory data as well as quality of life questionnaires were obtained. The primary outcome was change in postoperative Moorehead-Ardelt Quality of Life Questionnaire II Score (Moorehead Score). Secondary outcomes included common efficacy and safety outcomes utilized in bariatric surgery. Mixed ANOVA analysis, Chi Square test and Fisher's exact test were used.

Results

Overall, 108 patients who underwent conversion surgery were included. Mean duration of banding until conversion was 11.3 ± 4.3 years. The reason for conversion surgery was band failure in 45.4% (n=49) and band intolerance in 33.3% (n=36) of patients. In the remaining 21.3% (n=23) of cases a combination of both failure and intolerance was present. Mean follow-up time was 53 months. Postoperative mean Moorehead Score increased significantly after one (1.6 ± 0.9, p&lt;0.01) and after five years (1.6 ± 0.8, p&lt;0.01) compared to baseline values (0.7 ± 1.1). Mixed ANOVA analysis showed a significantly superior increase in Moorehead Score in males (p=0.024). No other significant predictors were identified. Neither the reason for conversion, nor preoperative parameters or long-term postoperative outcome parameters including postoperative weight loss or safety outcomes significantly affected postoperative quality of life improvement. Lasting BMI reduction (-4.6 kg/m2, p&lt;0.01) to 33.0 ± 6.7 kg/m2 and weight loss (-12.9%, p&lt;0.01) five years after conversion surgery were present. Internal hernia was the most common early postoperative complication, occurring in 14.8% (n=16) of cases.

Conclusion

Band removal with concomitant gastric bypass in patients with failed gastric banding improves long-term quality of life and may be the rescue procedure of choice in this setting.

Meta-analysis of randomized controlled trials comparing minimal-invasive versus open pancreatic surgery

Objective

To compare perioperative outcomes of minimal-invasive pancreatic surgery (MIPS) to open pancreatic surgery (OPS) using data obtained from randomised controlled trials (RCTs).

Methods

Literature search was done in CENTRAL, Medline and Web of Science; all currently available RCTs comparing MIPS and OPS in adult patients requiring elective distal pancreatectomy (DP) or partial pancreatoduodenectomy (PD) were included in the analysis. Outcomes were mortality, general and pancreatic surgery specific morbidity and length of hospital stay (LOS). Subgroup analysis between PD and DP was performed. A random-effects model for Mantel-Haenzsel and inverse variance analysis was used. Cochrane RoB 2.0 tool and GRADE approach was used for assessment of risk of bias and certainty of evidence.

Results

A total of 166 patients for DP (80 MIPS vs. 86 OPS) in two RCTs and 856 for PD (429 MIPS vs. 427 OPS) in five RCTs were analysed. Meta-analysis showed a reduction of LOS by 1.2 days (-2 to -0.3, p&lt;0.01) and intraoperative blood loss by 143 ml (-186 to -101, p&lt;0.01) in MIPS. In the subgroup analysis reduction of LOS was only present for minimal-invasive DP (-2 days, -2.3 to -1.7, p&lt;0.01). A minimal-invasive approach showed reduction of surgical site infections (odds ratio 0.4, 0.1 to 0.96, p=0.04) and intraoperative blood loss (-141 ml, -181 to -101, p&lt;0.01) only in PD. Duration of surgery was about 96 min longer in minimal-invasive PD (56 to 137 min, p&lt;0.01), but not in DP. Analysis showed no significant difference between MIPS and OPS, as well as between subgroups, in mortality, complications according to Clavien-Dindo &gt;=3 and pancreatic surgery specific complications like postoperative pancreatic fistula and delayed gastric emptying. Certainty of evidence according to the GRADE approach was moderate to low.

Conclusion

This meta-analysis of level 1 evidence shows reduced LOS and intraoperative blood loss in MIPS compared to OPS. Morbidity and mortality did not differ between MIPS and OPS. Longer duration of surgery in minimal-invasive PD hints that minimal-invasive technique in PD is more challenging than in DP. However, patients undergoing minimal-invasive PD seem to benefit from lower surgical site infections and less intraoperative blood loss.

Study of Parameters Involved in Specific Immunoadsorption of Apolipoprotein B

A therapeutic immunoadsorption system on immobilized and anti-apolipoprotein B as a plasma cholesterol lowering procedure was optimized. Several antibodies were compared and highest adsorption capacity was obtained with goat polyclonal antibodies. Optimum quantities of antibodies to be immobilized on the gel and quantities of apo-B to be applied to columns were determined. The amount of antibodies released from immunoadsorbents can be minimized by treatment with a 0.005% glutaraldehyde solution with an acceptable reduction rate of adsorption capacity. Each phase, adsorption and desorption respectively, were well-defined and synchronized so two columns could be used in parallel in an automated procedure.

In these conditions, the immunoadsorption system can efficiently, specifically and safely remove cholesterol and has to be subjected to clinical trials.

Model-based exposure-response analysis of apixaban to quantify bleeding risk in special populations of subjects undergoing orthopedic surgery

Population pharmacokinetic (PK) and exposure-response analyses of apixaban were performed using data from phase I-III studies to predict bleeding risks for patients receiving apixaban 2.5 mg b.i.d. after total knee or hip replacement (TKR, THR) surgery (N = 5,510). Renal function, age, gender, and body weight impacted apixaban exposure. Bleeding risk increased as a function of exposure. Predicted bleeding frequencies for TKR and THR populations at risk for high apixaban exposure (female, age > 75 years, calculated creatinine clearance (cCrCL) < 30 ml/min, body weight < 50 kg) (6.85 and 10.3%, respectively) were comparable to the reference population (male/female, age 65-75 years, cCrCL ≥ 80 ml/min, body weight 65-85 kg) (6.18 and 9.32%, respectively). A 100% increase in apixaban exposure is expected to raise bleeding frequencies to 7.25% (TKR) and 10.9% (THR), whereas a 200% increase would raise them to 8.49 and 12.7%. Coexistence of combined patient risk factors or doubling of exposure is not likely to result in a substantial, clinically relevant increase in bleeding risk with 2.5 mg b.i.d. apixaban.

[Image guiding techniques and navigation for TACE, SIRT and TIPS]

CLINICAL/METHODICAL ISSUE

To avoid non-targeted embolization in liver tumors, arteries important for embolization must be detected. In transarterial chemoembolization (TACE) arteries for particle embolization have to be detected and in selective internal radiotherapy (SIRT) extrahepatic arteries which must be protected from embolization have to be detected. In transjugular intrahepatic portosystemic shunt (TIPS) the problem is to achieve an exactly targeted puncture of the portal vein.

STANDARD RADIOLOGICAL METHODS

In TACE and SIRT detection of the vessels is performed from various angles by digital subtraction angiography (DSA). In TIPS puncture is guided by ultrasound or performed blindly.

METHODICAL INNOVATIONS

Using cone beam CT (CBCT) very small vessels in the liver can be visualized and 2D-3D back projection is able to detect the exact position of the portal vein in TIPS.

ACHIEVEMENTS

The use of CBCT and 2D-3D back projection significantly enhances navigation of vessels.

PRACTICAL RECOMMENDATIONS

If flat detector technique is available CBCT should be used in TACE and SIRT and 2D-3D navigation needs hardware and software updates.

[Personalized molecular medicine: new paradigms in the treatment of cochlear implant and cancer patients]

OBJECTIVES

To evaluate present options for the indication of cochlear implants (CI) and new forms of treatment for head and neck cancer, melanomas and basal cell carcinomas, with emphasis on future perspectives.

METHODS

A literature search was performed in the PubMed database. Search parameters were "personalized medicine", "individualized medicine" and "molecular medicine".

RESULTS

Personalized medicine based on molecular-genetic evaluation of functional proteins such as otoferlin, connexin 26 and KCNQ4 or the Usher gene is becoming increasingly important for the indication of CI in the context of infant deafness. Determination of HER2/EGFR mutations in the epithelial growth factor receptor (EGFR) gene may be an important prognostic parameter for therapeutic decisions in head and neck cancer patients. In basal cell carcinoma therapy, mutations in the Hedgehog (PCTH1) and Smoothened (SMO) pathways strongly influence the indication of therapeutic Hedgehog inhibition, e.g. using small molecules. Analyses of c-Kit receptor, BRAF-600E and NRAS mutations are required for specific molecular therapy of metastasizing melanomas. The significant advances in the field of specific molecular therapy are best illustrated by the availability of the first gene therapeutic procedures for treatment of RPE65-induced infantile retinal degradation.

CONCLUSION

The aim of personalized molecular medicine is to identify patients who will respond particularly positively or negatively (e.g. in terms of adverse side effects) to a therapy using the methods of molecular medicine. This should allow a specific therapy to be successfully applied or preclude its indication in order to avoid serious adverse side effects. This approach serves to stratify patients for adequate treatment.

Correlation from undiluted vitreous cytokines of untreated central retinal vein occlusion with spectral domain optical coherence tomography

PURPOSE

To correlate inflammatory and proangiogenic key cytokines from undiluted vitreous of treatment-naïve central retinal vein occlusion (CRVO) patients with SD-OCT parameters.

METHODS

Thirty-five patients (age 71.1 years, 24 phakic, 30 nonischemic) underwent intravitreal combination therapy, including a single-site 23-gauge core vitrectomy. Twenty-eight samples from patients with idiopathic, non-uveitis floaterectomy served as controls. Interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and vascular endothelial growth factor (VEGF-A) levels were correlated with the visual acuity (logMar), category of CRVO (ischemic or nonischemic) and morphologic parameters, such as central macular thickness-CMT, thickness of neurosensory retina-TNeuro, extent of serous retinal detachment-SRT and disintegrity of the IS/OS and others.

RESULTS

The mean IL-6 was 64.7pg/ml (SD ± 115.8), MCP-1 1015.7 ( ± 970.1), and VEGF-A 278.4 ( ± 512.8), which was significantly higher than the control IL-6 6.2 ± 3.4pg/ml (P=0.06), MCP-1 253.2 ± 73.5 (P<0.0000001) and VEGF-A 7.0 ± 4.9 (P<0.0006). All cytokines correlated highly with one another (correlation coefficient r=0.82 for IL-6 and MCP-1; r=0.68 for Il-6 and VEGF-A; r=0.64 for MCP-1 and VEGF-A). IL-6 correlated significantly with CMT, TRT, SRT, dIS/OS, and dELM. MCP-1 correlated significantly with SRT, dIS/OS, and dELM. VEGF-A correlated not with changes in SD-OCT, while it had a trend to be higher in the ischemic versus the nonischemic CRVO group (P=0.09).

CONCLUSIONS

The inflammatory cytokines were more often correlated with morphologic changes assessed by SD-OCT, whereas VEGF-A did not correlate with CRVO-associated changes in SD-OCT. VEGF inhibition alone may not be sufficient in decreasing the inflammatory response in CRVO therapy.

Effect of a high-fat meal on the pharmacokinetics of dapagliflozin, a selective SGLT2 inhibitor, in healthy subjects

Dapagliflozin is a potent and selective inhibitor of sodium-glucose co-transporter type 2 that is being developed for the treatment of type 2 diabetes mellitus. This open-label, randomized, two-period, two-treatment (single doses of 10-mg dapagliflozin fasted or fed), crossover study was conducted to evaluate the effect of a high-fat meal on the pharmacokinetics of dapagliflozin in 14 healthy subjects. Compared to the fasted state, a high-fat meal decreased mean dapagliflozin maximum plasma concentrations (C(max) ) by 31%, increased the time to C(max) (T(max) ) by 1 h, but did not affect overall dapagliflozin systemic exposure [area under the plasma concentration-time curve (AUC)]. As the cumulative (daily) amount of glucose excreted in the urine induced by dapagliflozin is dependent upon dapagliflozin AUC, the effect of food on dapagliflozin C(max) is unlikely to have a clinically meaningful effect on dapagliflozin's efficacy. On the basis of these findings, dapagliflozin can be administered without regard to meals.

Lack of pharmacokinetic interaction between dapagliflozin, a novel sodium-glucose transporter 2 inhibitor, and metformin, pioglitazone, glimepiride or sitagliptin in healthy subjects

AIMS

Dapagliflozin increases urinary glucose excretion by selectively inhibiting renal sodium-glucose transporter 2, an insulin-independent mechanism of action that may be complementary to that of other oral antidiabetes drugs. The current studies assessed the potential for pharmacokinetic (PK) interaction between dapagliflozin and pioglitazone, metformin, glimepiride or sitagliptin in healthy subjects following single-dose administration.

METHODS

In open-label, randomized, three-period, three-treatment crossover studies, 24 subjects received 50 mg dapagliflozin, 45 mg pioglitazone or the combination, while 18 subjects received 20 mg dapagliflozin, 1000 mg metformin or the combination. In an open-label, randomized, five-period, five-treatment, unbalanced crossover study, 18 subjects first received 20 mg dapagliflozin, 4 mg glimepiride or the combination, and afterward 100 mg sitagliptin or sitagliptin plus 20 mg dapagliflozin. Blood samples were taken over 72 h of each treatment period. Lack of PK interaction was defined as the ratio of geometric means and 90% confidence interval (CI) for combination:monotherapy being within the range of 0.80-1.25.

RESULTS

Co-administration of dapagliflozin with pioglitazone, metformin, glimepiride or sitagliptin had no effect on dapagliflozin maximum plasma concentration (C(max) ) or area under the plasma concentration-time curve (AUC). Similarly, dapagliflozin did not affect the C(max) or AUC for the co-administered drug, except for slight extensions of the 90% CI for the ratio of geometric means for glimepiride AUC (upper limit 1.29) and pioglitazone C(max) (lower limit 0.75). All monotherapies and combination therapies were well tolerated.

CONCLUSION

Dapagliflozin can be co-administered with pioglitazone, metformin, glimepiride or sitagliptin without dose adjustment of either drug.

Altered expression of securin (Pttg1) and serpina3n in the auditory system of hearing-impaired Tff3-deficient mice

INTRODUCTION

Tff3 peptide exerts important functions in cytoprotection and restitution of the gastrointestinal (GI) tract epithelia. Moreover, its presence in the rodent inner ear and involvement in the hearing process was demonstrated recently. However, its role in the auditory system still remains elusive. Our previous results showed a deterioration of hearing with age in Tff3-deficient animals.

RESULTS

Present detailed analysis of auditory brain stem response (ABR) measurements and immunohistochemical study of selected functional proteins indicated a normal function and phenotype of the cochlea in Tff3 mutants. However, a microarray-based screening of tissue derived from the auditory central nervous system revealed an alteration of securin (Pttg1) and serpina3n expression between wild-type and Tff3 knock-out animals. This was confirmed by qRT-PCR, immunostaining and western blots.

CONCLUSIONS

We found highly down-regulated Pttg1 and up-regulated serpina3n expression as a consequence of genetically deleting Tff3 in mice, indicating a potential role of these factors during the development of presbyacusis.

Quantification of apixaban's therapeutic utility in prevention of venous thromboembolism: selection of phase III trial dose

A model-based approach was used to integrate data from a phase II study in order to provide a quantitative rationale for selecting the apixaban dosage regimen for a phase III trial. The exposure-response models demonstrated that an increase in daily steady-state area under the plasma concentration-vs.-time curve (AUC(ss)) of 1 microg x h/ml would increase the odds ratio for major bleeding by 0.118 and decrease the odds ratio for venous thromboembolism (VTE) by 0.0499. The therapeutic utility index (TUI) was used to integrate the efficacy and safety predictions to quantify apixaban's efficacy/safety balance as a function of AUC(ss). Of the apixaban dosage regimens tested in phase II, the 2.5 mg twice-daily (b.i.d.) dosage regimen had the highest TUI (86.2%). This was also higher than the TUI for either 30 mg b.i.d. enoxaparin (82.5%) or for warfarin (71.8%). Subjects with moderate renal impairment are expected to have a 43% increase in apixaban exposure; however, apixaban's TUI suggests that dose adjustment is not needed in these subjects with renal impairment.

Dapagliflozin treatment in patients with different stages of type 2 diabetes mellitus: effects on glycaemic control and body weight

AIM

Dapagliflozin is a stable, competitive, reversible, and highly selective inhibitor of sodium-glucose co-transporter 2, the major transporter responsible for renal glucose reabsorption. With an insulin-independent mechanism of action, dapagliflozin is currently being developed for the treatment of type 2 diabetes mellitus (T2DM). This work aims to compare the efficacy of dapagliflozin, as measured by the change in hemoglobin A1c concentration (A1c) and body weight, and to determine the pharmacodynamic effects of dapagliflozin, as measured by urinary glucose excretion in early-stage and late-stage T2DM patient populations.

METHODS

A total of 151 early-stage patients and 58 late-stage patients with T2DM randomly assigned 10 or 20 mg once daily (QD) dapagliflozin treatment or placebo for 12 weeks from two phase 2 studies were included in the analysis. A1c, body weight, and urinary glucose were compared between the two patient populations.

RESULTS

Compared with the early-stage population, patients in the late-stage population had a longer duration of T2DM and higher baseline levels of A1c, body weight, fasting plasma glucose, and urinary glucose excretion. After 12 weeks of dapagliflozin treatment, A1c reduction, weight loss, and increased urinary glucose excretion from baseline were observed in both populations. Baseline A1c level impacted the A1c reduction after dapagliflozin treatment with a comparable effect in patients with early and late stage disease. Late-stage patients had greater reduction in body weight. There was no statistically significant difference in the amount of urinary glucose excretion between the early-stage and late-stage patients.

CONCLUSIONS

Dapagliflozin treatment at 10 and 20 mg QD for 12 weeks resulted in significant improvement in glycaemic control and body weight reduction in both early-stage and late-stage patients with T2DM. The findings suggest that dapagliflozin could be a promising treatment option for a wide range of patients with T2DM.

Association of human cathelicidin (hCAP-18/LL-37) gene expression with cardiovascular disease risk factors

BACKGROUND AND AIMS

Antimicrobial peptides (AMPs) are components of the innate immune system. In addition, evidence suggests that these peptides are associated with various inflammatory diseases. We examined whether expression of the cathelicidin LL-37 in peripheral blood mononuclear cells (PBMCs) is associated with cardiovascular risk factors.

METHODS AND RESULTS

A total of 90 men and 87 women selected from STANISLAS cohort were studied. Expression of LL-37 mRNA isolated from PBMCs of these subjects was quantified by quantitative RT-PCR. Anthropometric measurements and biochemical profiles were assessed for each individual. In women, LL-37 mRNA expression was significantly and positively correlated with body mass index (BMI) (p<or=0.001); waist circumference (WC) (p<or=0.01); systolic blood pressure (SBP) (p<or=0.05) and triglycerides (TG) level (p<or=0.05) and negatively with plasma levels of HDL-C (p<or=0.05). In men however, LL-37 was positively associated with waist to hip ratio (WHR) (p<or=0.05); SBP (p<or=0.001); TG (p<or=0.05); fasting glucose levels (p<or=0.01); alanine aminotransferase (ALT) activity (p<or=0.01); neutrophils counts (p<or=0.01) and negatively with lymphocyte counts (p<or=0.001); serum HDL-C (p<or=0.001) and apoA-I (p<or=0.05) levels. After adjustment for WC and BMI, multiple regression analysis showed that LL-37 remained significantly associated with SBP; HDL-C; fasting glucose level; ALT activity; neutrophil and lymphocyte counts (p<or=0.001 to p<or=0.05) in men.

CONCLUSION

Our results suggest that LL-37 gene expression may be closely associated with cardiovascular risk factors independently of BMI and WC. However, functional studies are required to confirm these data.

3D Road-Mapping in the Endovascular Treatment of Cerebral Aneurysms and Arteriovenous Malformations

SUMMARY

3D road-mapping with syngo iPilot was used as an additional tool for assessing cerebral aneurysms and arteriovenous malformations (AVMs) for endovascular therapy. This method provides accurate superimposition of a live fluoroscopic image (native or vascular road-map) and its matching 2D projection of the 3D data set, delivering more anatomic information on one additional display. In the endovascular management of cases with complex anatomy, 3D road-mapping provides excellent image quality at the intervention site. This method can potentially reduce intervention time, the number of DSA runs, fluoroscopy time and the amount of contrast media used in a procedure, with reservation for these factors being mainly operator-dependent. 3D road-mapping probably does not provide any advantage in the treatment of cerebral aneurysms or AVMs with very simple configuration, and it should not be used when acquisition of an optimum 3D data set is not feasible.

[The Treatment of the Complex Regional Pain Syndrome (CRPS 1 and CRPS 2) of the Upper Limb with Repeated Local Anaesthesia to the Stellate Ganglion.]

Two female patients were referred to us with a complex regional pain syndrome (CRPS) of the upper limb. One patient developed a CRPS type 1 after a radius fracture, the other presented a CRPS type 2 after a wrist trauma with a nerve injury of N. ulnaris. Both patients had progressive pain in spite of medical treatment (NSAID, Gabapentine, Calcitonine), physiotherapy, occupational therapy and osteopathy. In addition to pain they also showed the typical autonomic symptoms like oedema, hyperhidrosis, disturbances of skin colour and temperature and a severely limited motility of wrist and fingers. The clinical symptoms of both types of CRPS are identical and not restricted to the peripheral nerve distribution. The sympathetic nerve system is not only involved in the pain mechanism with reflectory processes in the segment and with the sympathetic afferent coupling, it also takes part in the neuroplasticity and in the neurogenic inflammation. The logical therapeutic intervention is therefore to normalize the hyperactivity of the sympathetic nerve systems with local anaesthetics. This regulation is done with injections to the stellate ganglion if upper limbs are affected (affections of lower limbs are treated with injections to the lumbar sympathetic trunk). Repeated injections to the stellate ganglion caused immediate improvement of pain and other symptoms in both patients.

Dapagliflozin, a novel, selective SGLT2 inhibitor, improved glycemic control over 2 weeks in patients with type 2 diabetes mellitus

Dapagliflozin, administered to patients in once-daily oral doses, is a sodium-glucose cotransporter 2 (SGLT2) inhibitor that blocks the reabsorption of glucose from urine into the blood. This 14-day study randomized patients with type 2 diabetes mellitus (T2DM) to four treatment groups receiving daily oral doses of 5-, 25-, or 100-mg doses of dapagliflozin or placebo, in order to evaluate glucosuria and glycemic parameters. Significant reductions in fasting serum glucose (FSG) were observed on day 2 with 100 mg dapagliflozin (-9.3%, P < 0.001), and dose-dependent reductions were observed on day 13 with the 5-mg (-11.7%; P < 0.05), 25-mg (-13.3%; P < 0.05), and 100-mg (-21.8%; P < 0.0001) doses as compared with placebo. Significant improvements in oral glucose tolerance test (OGTT) were observed with all doses on days 2 and 13 (P < 0.001 as compared with placebo). On day 14, urine glucose values were 36.6, 70.1, and 69.9 g/day for the 5-, 25-, and 100-mg doses (as compared with no change for placebo), which were slightly lower than those on day 1. This was attributed to the decrease in filtered glucose load following improved glycemic control. Dapagliflozin produced dose-dependent increases in glucosuria and clinically meaningful changes in glycemic parameters in T2DM patients.

[Propionic acidemia and sensorineural hearing loss: is there a connection at the molecular genetics level?]

CURRENT KNOWLEDGE

Propionic acidemia is caused by a gene defect leading to malfunction of the enzyme propionyl-CoA carboxylase (PCC) and in turn to a pathologic accumulation of propionic acid. Many mutations have been found at the molecular genetic level over the past 20 years, and their implications for the limitation of enzyme activity of PCC in propionic acidemia are discussed.

SCIENTIFIC QUESTION AND AIMS OF THE STUDY

As an elevated incidence of deafness has been observed in patients with propionic acidemia, the question arises of whether mutations primarily responsible for this disease could also be the underlying cause for a genetic form of deafness.

METHODS AND RESULTS

As well as a standard pure tone audiogram, a pedigree was elaborated and DNA isolated for each family concerned. In one family several subjects displayed mutations of both the PCCA and the PCCB -subunits; these included only one girl whose phenotype was affected, however.

CONCLUSIONS

Mutation of the PCCB subunit p.R113X has not previously been mentioned in the literature. According to our present knowledge no connection can be assumed between either of the two mutations and the severe sensorineural hearing loss.

Contribution of the N-acetyltransferase 2 polymorphism NAT2*6A to age-related hearing impairment

BACKGROUND

Age-related hearing impairment (ARHI) is the most common sensory impairment in older people, affecting 50% of those aged 80 years. The proportion of older people is increasing in the general population, and as a consequence, the number of people affected with ARHI is growing. ARHI is a complex disorder, with both environmental and genetic factors contributing to the disease. The first studies to elucidate these genetic factors were recently performed, resulting in the identification of the first two susceptibility genes for ARHI, NAT2 and KCNQ4.

METHODS

In the present study, the association between ARHI and polymorphisms in genes that contribute to the defence against reactive oxygen species, including GSTT1, GSTM1 and NAT2, was tested. Samples originated from seven different countries and were combined into two test population samples, the general European population and the Finnish population. Two distinct phenotypes for ARHI were studied, Z(low) and Z(high), representing hearing in the low and high frequencies, respectively. Statistical analysis was performed for single polymorphisms (GSTM1, GSTT1, NAT2*5A, NAT2*6A, and NAT2*7A), haplotypes, and gene-environment and gene-gene interactions.

RESULTS

We found an association between ARHI and GSTT1 and GSTM1 in the Finnish population sample, and with NAT2*6A in the general European population sample. The latter finding replicates previously published data.

CONCLUSION

As replication is considered the ultimate proof of true associations in the study of complex disorders, this study provides further support for the involvement of NAT2*6A in ARHI.

Single-nucleotide polymorphisms in the COL1A1 regulatory regions are associated with otosclerosis

Otosclerosis (MIM 166800) has a prevalence of 0.2-1% among white adults, making it the single most common cause of hearing impairment in this ethnic group. Although measles virus, hormones, human leukocyte antigen alleles and genetic factors have been implicated in the development of otosclerosis, its etiology remains unknown. In a focused effort to identify genetic factors in otosclerosis, we have mapped four disease loci (MIM 166800/605727/608244/608787); however, cloning the disease-causing genes in these intervals has not been successful. Here, we used a case-control study design to investigate the association between collagen type I genes and otosclerosis. We identified susceptibility and protective haplotypes in COL1A1 that are significantly associated with otosclerosis in the Caucasian population. These haplotypes alter reporter gene activity in an osteoblast cell line by affecting binding of transcription factors to cis-acting elements. Our data suggest that increased amounts of collagen alpha1(I) homotrimers are causally related to the development of otosclerosis. Consistent with this hypothesis, mouse mutants homozygous for a Col1a2 frameshift mutation on a C57BL/6J background that deposit only homotrimeric type I collagen have hearing loss.

Loss of function mutations of the GJB2 gene detected in patients with DFNB1-associated hearing impairment

Mutations in GJB2, which encodes the gap junction protein connexin 26 (Cx26), are one of the major causes for inherited and sporadic nonsyndromic hearing impairment. This study aimed to functionally characterize more frequent GJB2 mutations identified in patients showing nonsyndromic hearing impairment. Following injection of wild type and mutated cRNA in Xenopus oocytes, Cx26 hemichannel activity was measured by depolarization activated conductance in noncoupled oocytes. All mutants showed a partially or completely defective phenotype, except (V27I)Cx26, a polymorphism tested as positive control. Coexpression of wild type and mutant Cx26 injected at equimolar levels revealed that p.M34T, p.V37I and p.I82M, but not p.G59V, p.L90P, p.R127H and p.R143W exert a dominant inhibitory effect. When coexpressed with Cx30, a connexin partially colocalized with Cx26 in the cochlea, all mutants had a dominant behavior. This study provides data that might be important for the improvement of genetic diagnosis and counseling for patients with hearing impairment.

Association of CYP2A6*1B genetic variant with the amount of smoking in French adults from the Stanislas cohort

This study was designed in order to investigate the influence of the genetic polymorphism of CYP2A6 on the amount of smoking. In all, 463 French adults included in the Stanislas cohort were studied and underwent two examinations at 5 years distance (t0 and t(+5) years). Information on their smoking habits was collected. They were genotyped by RFLP for the CYP2A6*1A, CYP2A6*1B and CYP2A6*4 alleles. CYP2A6*1B and CYP2A6*4 allele frequencies were 32 and 4%, respectively. The subjects carrying the CYP2A6*1B allele oxidize nicotine to cotinine faster than subjects with the CYP2A6*1A allele. The number of cigarettes smoked per day was significantly higher in the CYP2A6*1B/*1B group as compared to the CYP2A6*1A/*1A group (P = 0.01 at t0; P = 0.001 t(+5) years), with a larger increase in their daily cigarettes consumption over the 5-year period (P = 0.006). No significant difference in the smoking status was observed according to the CYP2A6 genotype. These data suggest that the CYP2A6*1B is associated with the number of cigarettes smoked per day.

[Mitochondrial A1555G mutation. Molecular genetic diagnosis in sporadic cases of non-syndromic hearing impairment]

BACKGROUND

The A1555G mutation in mitochondrial DNA is the cause of hearing impairment in about 50% of all carriers. The severity and onset of this impairment is predominantly affected by the use of aminoglycosides.

PATIENTS AND METHODS

A total of 391 patients displaying sporadic, non-syndromic, mild to severe hearing impairment were analyzed for the A1555G mutation using molecular genetic methods.

RESULTS

We analysed additional family members of the two patients (0.5% of the total) who had the mutation. All maternal relatives carried the mutation, but only three individuals from the two families displayed a variable sensorineural hearing loss.

CONCLUSION

The A1555G mutation is infrequently involved as a genetic cause of sporadic, non-syndromic hearing impairment. Nevertheless, based on the variable clinical outcome of hearing impairment and the possibility of preventive steps, a genetic test in this patient subgroup is indicated.

[Mitochondrial hearing impairment. Background, genetic predisposition and possibilities for diagnosis]

Hearing impairment (HI) is one of the most common neurosensory disorders, with sensorineural hereditary HI being the most common form. Mitochondrial maternally inherited HI appears to be increasing in frequency. The incidence of mitochondrial defects causing HI is estimated to be between 6 and 33% of all hearing deficiencies, with an even higher percentage for some syndromic cases. This review summarises the syndromic and non-syndromic characteristics of sensorineural HI based on mutations in mitochondrially encoded genes, the relationship to aminoglycoside-induced HI and related diagnostic tools.

[Paraganglioma in the area of the head and neck. A review of molecular genetic research]

Paragangliomas of the head and neck region are usually benign tumors that develop from chemoreceptors of paraganglionic origin in the majority of patients. These receptors play an important role in sensing and regulation of the blood CO(2) level. Genetic alterations in the mitochondrial enzyme complex II (SDH), which is involved in respiratory chain and citric acid cycle reactions, have been shown to lead to sporadic as well as familial cases of these tumors. The gene encoding the subunit SDHD shows mutations in up to 50% of these cases. In addition, loss of heterozygosity (LOH) was demonstrated in these tumor samples and has been shown to be connected with oncogenesis of paragangliomas. Thus, SDHD is the first known tumor suppressor gene encoding a mitochondrial protein. In this article we summarize the current state of knowledge concerning the development of paragangliomas.

Refinement of the DFNA4 locus to a 1.44�Mb region in 19q13.33

Many forms of autosomal dominant non-syndromic hearing impairment are known. While the underlying gene defects and causative mutations have been discovered for some forms, the gene responsible for DFNA4 has remained elusive to date. Examination of a German four-generation kindred led to the identification of a 1.44 Mb map segment in contig NT_011109 as being the most likely DFNA4 candidate region in 19q13.33. The recombination breakpoints in this family and the intervals of two previously reported DFNA4 families allowed us to delineate a minimum consensus region between the markers D19S879 and D19S246. In our family, a maximum two-point LOD score of 4.5 was obtained at theta = 0 for the marker D19S867. Within the refined DFNA4 interval the public databases list more than 50 genes, from which several appear to be promising DFNA4 candidates due to similarities with animal models and with other causative genes involved in hearing disability.

Waardenburg-Syndrom

BACKGROUND

Waardenburg syndrome (WS) is an autosomal dominant disorder characterised by pigmentary anomalies of the skin, hairs, eyes and various defects of other neural crest derived tissues. It accounts for over 2% of congenital hearing impairment. At least four types are recognized on the basis of clinical and genetic criteria.

PATIENTS AND METHODS

Based on a screening of congenitally hearing impaired children, 12 families with WS type II were detected. Of special interest was the phenotype of these families, in particular the reduced penetrance of hearing impairment within the families.

RESULTS AND CONCLUSION

In all cases a high variability of the disease phenotype was detected and the penetrance of the clinical traits varied accordingly. Therefore, it is not possible to predict the clinical phenotype even in a single family. Based on these studies, we plan to identify the pathogenetic cause of the disease in order to perform a detailed genotype/phenotype analysis.

Phänotypische Charakterisierung einer DFNA6-Familie mit Tieftonschwerhörigkeit

BACKGROUND

Hereditary hearing impairment is a heterogeneous sensory defect with approximately two-thirds of all cases being nonsyndromic. Only two loci (DFNA1 and DFNA6/14/38) are associated with low frequency sensorineural nonsyndromic hearing impairment. DFNA6 was mapped to chromosome 4p16. Recessive mutations in the WFS1 gene are responsible for Wolfram syndrome; missense mutations inherited as an autosomal dominant result in low frequency sensorineural hearing impairment (LFSNHI).

PATIENTS AND METHODS

In this study we analyzed the phenotype of a large Hungarian family with LFSNHI and linkage to DFNA6. The family contains 14 affected persons.

RESULTS AND CONCLUSION

In general, these patients show a postlingual, sensorineural, bilateral, symmetric, nonsyndromic low frequency hearing impairment with a slow progression. This impairment is accompanied by normal vision and normal vestibular responses.

[Clinical and molecular genetic analysis of monozygotic twins displaying stapes gusher syndrome (DFN3)]

BACKGROUND

DFN3 ( "stapes gusher") is the most frequent form of X-linked hearing impairment. It accounts for up to 0.5% of all cases of severe childhood hearing disorders.

PATIENTS AND METHODS

Monozygotic twins with suspected stapes gusher syndrome, their mother, and control individuals were analyzed clinically and genetically.

RESULTS

The clinical investigations confirmed a DFN3 phenotype in both brothers who displayed all typical symptoms. A molecular genetic investigation of the POU3F4 gene, which plays an essential role in the development of DFN3, was also performed. No chromosomal aberrations within the coding region of POU3F4were detected. Since several authors have described mutations in the 5' untranslated region of the gene also resulting in a DFN3 phenotype, we screened this area by microsatellite analysis and detected a double deletion localized in the critical interval. This is the first description of a double deletion in the non-coding region of POU3F4 leading to DFN3 phenotype.

CONCLUSION

Interestingly, in spite of having an identical genotype, the twins displayed significant phenotypic differences. This underlines the importance of exogenous factors in the development of inherited pathological processes.