[Functional anatomy of the cochlear nerve and the central auditory system]

The auditory pathways are a system of afferent fibers (through the cochlear nerve) and efferent fibers (through the vestibular nerve), which are not limited to a simple information transmitting system but create a veritable integration of the sound stimulus at the different levels, by analyzing its three fundamental elements: frequency (pitch), intensity, and spatial localization of the sound source. From the cochlea to the primary auditory cortex, the auditory fibers are organized anatomically in relation to the characteristic frequency of the sound signal that they transmit (tonotopy). Coding the intensity of the sound signal is based on temporal recruitment (the number of action potentials) and spatial recruitment (the number of inner hair cells recruited near the cell of the frequency that is characteristic of the stimulus). Because of binaural hearing, commissural pathways at each level of the auditory system and integration of the phase shift and the difference in intensity between signals coming from both ears, spatial localization of the sound source is possible. Finally, through the efferent fibers in the vestibular nerve, higher centers exercise control over the activity of the cochlea and adjust the peripheral hearing organ to external sound conditions, thus protecting the auditory system or increasing sensitivity by the attention given to the signal.

Neurocognitive testing in late-onset Tay-Sachs disease: a pilot study

OBJECTIVES

To test neurocognitive function in patients with late-onset Tay-Sachs disease (LOTS) using a computerized system to assess whether cognition is a clinically relevant outcome measure of possible therapeutic intervention in LOTS.

METHODS

Ten adults with Tay-Sachs disease were administered at least one battery of the Mindstreams Neurotrax system for evaluation of cognitive function. Six sub-scores and a Global Cognitive Score (GCS) were tabulated. A disease specific severity score was also devised with six domains.

RESULTS

Despite identical genotypes, all patients but the two oldest had > or = 3/6 sub-scores one standard deviation below normal mean (100); verbal and executive functions were most affected. The severity score measured other functions.

CONCLUSIONS

Because of provocative findings on re-testing in patients exposed to miglustat, and despite the very small cohort, cognitive function may be an appropriate and clinically relevant outcome measure for future therapeutic interventions in LOTS.

Immobilization of uranium and arsenic by injectible iron and hydrogen stimulated autotrophic sulphate reduction

The main object of the study was the development of a long-term efficient and inexpensive in-situ immobilization technology for uranium (U) and arsenic (As) in smaller and decentralized groundwater discharges from abandoned mining processing sites. Therefore, corrosion of grey cast iron (gcFe) and nano-scale iron particles (naFe) as well as hydrogen stimulated autotrophic sulphate reduction (aSR) were investigated. Two column experiments with sulphate reducing bacterias (SRB) (biotic gcFe , biotic naFe) and one abiotic gcFe-column experiment were performed. In the biotic naFe column, no particle translocation was observed and a temporary but intensive naFe corrosion indicated by a decrease in E(h), a pH increase and H(2) evolution. Decreasing sulphate concentrations and (34)S enrichment in the column effluent indicated aSR. Fe(II) retention could be explained by siderite and consequently FeS precipitation by geochemical modeling (PhreeqC). U and As were completely immobilised within the biotic naFe column. In the biotic gcFe column, particle entrapment in open pore spaces resulted in a heterogeneous distribution of Fe-enriched zones and an increase in permeability due to preferential flow. However, Fe(II) concentrations in the effluent indicated a constant and lasting gcFe corrosion. An efficient immobilization was found for As, but not for U.

Description of the mutations in 15 subjects with variant forms of maple syrup urine disease

BACKGROUND

In maple syrup urine disease (MSUD), disease-causing mutations can affect the BCKDHA, BCKDHB or DBT genes encoding for the E1 alpha, E1 beta and E2 subunits of the multienzyme branched-chain 2-keto acid dehydrogenase (BCKD) complex.

AIM

The aim of this study was to screen DNA samples of 15 subjects with distinct well-characterized variant MSUD phenotypes for mutations in the three genes in order to demonstrate a potential correlation between specific nucleotide changes and particular variant phenotypes.

METHODS

The exonic coding sequences of all three genes were studied using genomic DNA and cellular RNA derived from peripheral blood leukocytes.

RESULTS

In 37% of the cases (total 30 alleles), disease-causing mutations were located in the BCKDHA, in 46% in the BCKDHB, and in 13% in the DBT gene. Novel mutations occurring homozygously were p.Ala328Thr in the BCKDHA gene and p.Gly249_Lys257del in the DBT gene. Both are associated with a mild MSUD variant. The same holds true for the novel mutations p.Pro200Ala in BCKDHB and p.Phe307Ser in DBT which were identified in heterozygous fashion. Among the known mutant alleles, p.Gly278Ser in the BCKDHB gene was relatively frequent and also associated with a mild MSUD variant.

CONCLUSION

The results of this study indicate that genotyping may be predictive of clinical severity of variant MSUD phenotypes and might be of prognostic value particularly in subjects with variant MSUD identified in newborn screening in whom early treatment fortunately slows the natural course of the disease.

[Avatars in face transplants]

Avatar carries a pejorative connotation often related to an unfortunate hazard. In face transplants, incarnations were numerous. The analysis of their evolution through time and increasing sophistication of procedures turn out to be informative regarding the wide disrepairs in the craniofacial area. The authors report the principal constraints of face transplant and the evolution in minds to deal with it.

The effect of hormone replacement therapy on cognitive function in post-menopausal women

BACKGROUND

Despite interest in causes of dementia in older persons, particularly in post-menopausal women, it is unclear whether hormone replacement therapy (HRT) is a risk factor.

AIM

To assess cognitive function in post-menopausal women with high educational status receiving HRT, compared to non-users.

DESIGN

Cognitive functioning was assessed with in women aged 55-60 years with at least university-level education, using the Mindstreams system, a computerized cognitive battery with multiple domains.

RESULTS

Of 165 women meeting the inclusion/exclusion criteria, 82 women (49.7%) declined participation. Of the remaining 83, 40 (48.2%) had never received HRT; the remainder was divided into women receiving 5-9 years HRT (n = 29)versus those with >or=10 years HRT (n = 11). There were no statistically significant differences between HRT users and non-users in global scores or sub-domains of cognitive functioning, and no difference between those women receiving HRT for 5-9 years vs. >or=10 years.

DISCUSSIONS

Long-term HRT does not appear to impair cognitive functioning in highly-educated women. Recommendations regarding post-menopausal HRT should be made on an individual basis.

Abatement of phenolic mixtures by catalytic wet oxidation enhanced by Fenton's pretreatment: effect of H2O2 dosage and temperature

Catalytic wet oxidation (CWO) of a phenolic mixture containing phenol, o-cresol and p-cresol (500mg/L on each pollutant) has been carried out using a commercial activated carbon (AC) as catalyst, placed in a continuous three-phase reactor. Total pressure was 16 bar and temperature was 127 degrees C. Pollutant conversion, mineralization, intermediate distribution, and toxicity were measured at the reactor outlet. Under these conditions no detoxification of the inlet effluent was found even at the highest catalyst weight (W) to liquid flow rate (Q(L)) ratio used. On the other hand, some Fenton Runs (FR) have been carried out in a batch way using the same phenolic aqueous mixture previously cited. The concentration of Fe(2+) was set to 10mg/L. The influence of the H(2)O(2) amount (between 10 and 100% of the stoichiometric dose) and temperature (30, 50, and 70 degrees C) on phenols conversion, mineralization, and detoxification have been analyzed. Phenols conversion was near unity at low hydrogen peroxide dosage but mineralization and detoxification achieved an asymptotic value at each temperature conditions. The integration of Fenton reagent as pretreatment of the CWO process remarkably improves the efficiency of the CWO reactor and allows to obtain detoxified effluents at mild temperature conditions and relatively low W/Q(L) values. For a given phenolic mixture a temperature range of 30-50 degrees C in the Fenton pretreatment with a H(2)O(2) dosage between 20 and 40% of the stoichiometric amount required can be proposed.

[A simple tissue expansion device for scalp defect]

INTRODUCTION

The closure of scalp defects requires various procedures, but unfortunately with a high rate of sequels.

OBSERVATION

The authors report their experience regarding a large pilomatrixoma of the scalp. The closure of an 8 by 10 cm defect resulting from excision was achieved using a simple tissular extension device during 20 days. The scar aspect was very satisfactory. The device is derived from Cohn's model. It is made of simple and widely used material (vascular lacks, staples).

DISCUSSION

This simplicity and efficiency of tissular extension devices has been proved. Nevertheless, their use may be restricted. This limitation often results from a high cost and difficulty in applying the adequate tension to the wound edges. Excessive tension may lead to cutaneous necrosis. The use of a simple device derived from Cohn's model seems interesting considering its efficiency, reliability, and low cost.

Analyse des implications du tissu graisseux dans la morphologie faciale, à partir d'une revue de la littérature et de dissections de dix hémifaces

The morphological implications of the fatty tissue of the face are unequal. We study these with a review of the literature and an anatomical study with dissections of 10 half-faces. The sub-cutaneous fat, over the superficialis fascia, have got the most important implications on the morphology. These depend of the localisations on the face and the age and the weight of each subject. We can observe modifications of the positions of this fatty layer on old subjects, but also a diminution of its volume. The sub-fascial fatty tissue, above the SMAS is represented by few fat pads and seems ,to bee less concerned by modifications of its volumes.

[Uni-axial tissular extension for covering skin defects of the limbs. A 31 cases review]

INTRODUCTION

The skin property to adapt to external constraints is widely used in plastic surgery. Tissue expansion is the most known and codified application. Tissue extension appears to be an attractive alternative. The authors propose the usage of a simplified procedure to deal with skin loss in the superior or inferior members.

MATERIAL AND METHOD

Thirty-one patients underwent uni-axial traction between February 2000 and October 2003.

RESULTS

Closure of skin loss on the upper member has been obtained in 6 days and in 8 days on the inferior member.

DISCUSSION

Efficiency, reliability and no subsequent aftermaths are strong arguments in favor of the development of a simplified extension procedure.

CONCLUSION

The tissue extension procedure, although scarcely used is an attractive procedure for the coverage of skin losses.

Social outcome in adults with maple syrup urine disease (MSUD)

BACKGROUND

In MSUD, dietary treatment aims at the protection of the brain from functional disturbances and structural damage by keeping the branched-chain amino acids in plasma permanently in the near-normal range. Unfortunately, delay in effective treatment of the neonatal manifestation and poor long-term metabolic control are common in MSUD patients, leading to impaired cognitive outcome. Some studies have analysed cognitive capacity but only few data are available on social status (educational qualification, interpersonal relationships, lifestyle) in adult patients, which is one measure for the success of treatment.

AIM

In this study we analysed sociodemographic data of 22 adult patients suffering from classic or very severe variant MSUD in comparison with data on an age-matched control collective of the population of Germany.

RESULTS

The analysis revealed low educational and professional levels with a low rate of participation in the labour force by adult MSUD patients. The educational level in patients of migrant origin was lower than the educational qualifications in the native patient group. A large number of patients did not live a normal adult life. Patients could not live autonomously, did not have a steady partnership and had no children.

CONCLUSION

Despite substantial improvement in the treatment of MSUD in recent years, unimpaired outcome of patients with classic or very severe variant MSUD remains a rare finding. Care must be further optimized in order to improve intellectual and, thereby, social outcome. Particular care must be exercised in the treatment of migrant patients who offer special problems due to cultural peculiarities and language difficulties.

La graisse de la face : anatomie descriptive et fonctionnelle à partir d'une revue de la littérature et de dissections de dix hémifaces

The aim of this study is to describe the anatomy of the fat in the face, based on a review of the literature and dissections of 10 half-faces. The facial fat can be divided in two layers. The first-one is superficial, between the skin and the superficialis fascia. Its function is essentially protective and its morphological implications are major, especially according to the facial aging. The other layer is deep, under the superficialis fascia. Its principal function is mechanical and its morphological implications are less important. This layer is made of several fat pads in continuity, excepted the buccal fat pad which is separated from the others by its own capsula. The other fat pads are the intra orbialis fat pad, the sub orbicularis oculi fat pad (SOOF), the retro orbicularis oculi fat pad (ROOF), the galeal fat pad and the temporal fat pad.

Intrahepatic cholestasis of pregnancy: the severe form is associated with common variants of the hepatobiliary phospholipid transporter ABCB4 gene

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is characterised by troublesome maternal pruritus, raised serum bile acid levels and increased fetal risk. Mutations of the ABCB4 gene encoding the hepatobiliary phospholipid transporter have been identified in a small proportion of patients with cholestasis of pregnancy. In a recent prospective study on 693 patients with cholestasis of pregnancy, a cut-off level for serum bile acid (> or =40 micromol/l) was determined for increased risk of fetal complications.

OBJECTIVES

To investigate whether common combinations of polymorphic alleles (haplotypes) of the genes encoding the hepatobiliary ATP-binding cassette (ABC) transporters for phospholipids (ABCB4) and bile acids (ABCB11) were associated with this severe form of cholestasis of pregnancy.

METHODS

For genetic analysis, 52 women with bile acid levels > or =40 micromol/l (called cases) and 52 unaffected women (called controls) matched for age, parity and geographical residence were studied. Gene variants tagging common ABCB4 and ABCB11 haplotypes were genotyped and haplotype distributions were compared between cases and controls by permutation testing.

RESULTS

In contrast with ABCB11 haplotypes, ABCB4 haplotypes differed between the two groups (p = 0.019), showing that the severe form of cholestasis of pregnancy is associated with the ABCB4 gene variants. Specifically, haplotype ABCB4_5 occurred more often in cases, whereas haplotypes ABCB4_3 and ABCB4_7 were more common in controls. These associations were reflected by different frequencies of at-risk alleles of the two tagging polymorphisms (c.711A: odds ratio (OR) 2.27, p = 0.04; deletion intron 5: OR 14.68, p = 0.012).

CONCLUSION

Variants of ABCB4 represent genetic risk factors for the severe form of ICP in Sweden.

Variant maple syrup urine disease (MSUD)--the entire spectrum

BACKGROUND

In the rare inborn autosomal recessive disorder maple syrup urine disease (MSUD) the accumulation of the branched-chain amino acids (BCAAs) and their metabolic products results in acute and chronic brain dysfunction. About 20% of the patients suffer from non-classic variant forms of MSUD of different clinical severity.

AIM

Up to now variant cases have mostly been published as individual case reports; the aim of this study was to give a comparative description of 16 individuals (aged 6-30 years) with different forms of variant MSUD.

METHODS

Laboratory data, information on clinical course and treatment as well as aspects of developmental, intellectual and social outcome were obtained retrospectively. Data from in vitro and in vivo methods measuring the degree of enzyme deficiency were included.

RESULTS

In addition to a mild phenotype, which fits well into the so-called intermittent variant, and a more severe phenotype with a wider range from a mild variant to an almost classic form, which fits well into the so-called intermediate variant, we assume the existence of an asymptomatic, non-disease variant of MSUD. These clinical phenotypes are not unambiguously differentiable on the basis of biochemical parameters.

CONCLUSION

A continuum of clinical severity from asymptomatic to very severe (border to classic) exists in variant MSUD. Apart from newborns with classic MSUD, also those with variant forms benefit from early diagnosis and start of adequate treatment.

[Hypertrophic diseases of facial fatty tissue]

Based on our own experience and a review of the literature, we des-cribe hypertrophic diseases concerning the fatty tissue of the face. Pathological patterns are numerous and polymporphous. Fatty localizations involving the face may be associated or not with specific histological presentation.

[Contribution of the pathology examination in the operating theatre in patients with skin cancer: retrospective analysis of 388 patients]

INTRODUCTION

Pathological examination in the operating theatre in patients undergoing resection of a skin cancer is one of the most adapted therapeutic approaches. We present our experience with 388 patients, comparing the rate of recurrence with or without operating-theatre pathological examination.

MATERIAL AND METHOD

The study population included 388 patients, mean age 69.5 years (28-98 years) who underwent resection of 544 skin tumors (520 primary and 36 recurrent), 76.6% unique tumors. The pathological examination of the surgical specimen was performed immediately after removal. This method was systematic procedure for spinocellular carcinomas, was not performed for basocellular carcinomas measuring less than 1 cm when well circumscribed and not peri-orifice, and when reconstruction was not planned.

RESULTS

The pathological examination was not performed in the operative theatre for 76 tumors; for 470 examinations performed in the operative theatre, at least one surgical margin was positive in 93 (19.8%). Anatomic regions concerned most were the tip of the nose and the eyelids. Recurrent tumors (5.0% of resections) accounted for 27% of the positive pathological results. Thirty-one patients had to have revision surgery, four after a false negative on the pathological examination performed in the operative theatre, four patients for a healing problem and 23 because of tumor recurrence (4%).

DISCUSSION

Pathological examination in the operative theatre can help decrease the rate of recurrence in comparison with classical surgery using empiric margins. This method is reliable if performed by an experienced pathologist so that reconstruction can be undertaken before the definitive pathological results are obtained, improving patient comfort. These therapeutic options have a cost however in terms of equipment and personnel. Indications should be well chosen and balanced against the advantages of a two-phase classical procedure.