The complex structure of Fomes fomentarius represents an architectural design for high-performance ultralightweight materials

High strength, hardness, and fracture toughness are mechanical properties that are not commonly associated with the fleshy body of a fungus. Here, we show with detailed structural, chemical, and mechanical characterization that Fomes fomentarius is an exception, and its architectural design is a source of inspiration for an emerging class of ultralightweight high-performance materials. Our findings reveal that F. fomentarius is a functionally graded material with three distinct layers that undergo multiscale hierarchical self-assembly. Mycelium is the primary component in all layers. However, in each layer, mycelium exhibits a very distinct microstructure with unique preferential orientation, aspect ratio, density, and branch length. We also show that an extracellular matrix acts as a reinforcing adhesive that differs in each layer in terms of quantity, polymeric content, and interconnectivity. These findings demonstrate how the synergistic interplay of the aforementioned features results in distinct mechanical properties for each layer.

Tuning the Size and Shape of NanoMOFs via Templated Electrodeposition and Subsequent Electrochemical Oxidation

The control over the size and shape of nanoMOFs is essential for their exploitation in integrated devices such as sensors, membranes for gas separation, photoelectrodes, etc. Here, we demonstrate the synthesis of nanowires and three-dimensionally interconnected nanowire networks of Cu-based metal-organic frameworks (MOFs) by a combination of ion-track technology and electrochemical methods. In particular, Cu nanowires and nanowire networks were electrodeposited inside polymeric etched ion-track membranes and subsequently converted by electrochemical oxidation into different Cu-based MOFs such as the well-known Cu₃(BTC)₂ (also known as HKUST-1) and the lesser-known MOF Cu(INA)₂. The MOFs are formed inside the template, therefore adopting the shape of the host nanochannels. The synthesized MOF nanowires exhibit tunable diameters between 80 and 260 nm. Characterization by X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, scanning electron microscopy, and transmission electron microscopy indicates that the employed electrochemical conversion includes the formation of Cu₂O as an intermediate, as well as the initial formation of an amorphous MOF phase, which crystallizes upon longer reaction times.

An overview of tuberculosis and migration

With nearly one billion migrants worldwide, migration is both a dynamic and a divisive phenomenon facing the world today. Migrants are a heterogeneous group, and the conditions surrounding migration pathways often pose risks to the physical, mental and social well-being of migrants, with certain subgroups being more vulnerable than others. Several determinants of health and tuberculosis (TB) interplay to increase the vulnerability of migrants to tuberculous infection, TB disease and poor treatment outcomes, making them a key population for TB. This article is the first in the State-of-the-Art series of the International Journal of Tuberculosis and Lung Disease on TB and migration. It provides an overview of migration trends, migration pathways and social determinants, and impact on TB. This article outlines a framework for the prevention and reduction of the TB burden among migrants, adapted from the World Health Organization's End TB Strategy, and in accordance with the Stop TB Partnership's Global Plan and the Sustainable Development Goals (SDGs) agenda. The framework highlights the need for migrant-inclusive national TB plans, and calls for action across all three pillars of the End TB Strategy for migrant-sensitive care and prevention, bold intersectoral policies and systems supportive of migrants, and operational research. More research is needed on the TB burden and challenges faced by migrants and on the feasibility and effectiveness of approaches proposed here and the scaling up of models already underway. Political commitment at the highest national and international levels will be critical to intensify action for promoting the health of migrants on the road to achieving the end TB targets.

Mutation analysis of TMC1 identifies four new mutations and suggests an additional deafness gene at loci DFNA36 and DFNB7/11

Hearing loss is the most frequent sensorineural disorder affecting 1 in 1000 newborns. In more than half of these babies, the hearing loss is inherited. Hereditary hearing loss is a very heterogeneous trait with about 100 gene localizations and 44 gene identifications for non-syndromic hearing loss. Transmembrane channel-like gene 1 (TMC1) has been identified as the disease-causing gene for autosomal dominant and autosomal recessive non-syndromic hearing loss at the DFNA36 and DFNB7/11 loci, respectively. To date, 2 dominant and 18 recessive TMC1 mutations have been reported as the cause of hearing loss in 34 families. In this report, we describe linkage to DFNA36 and DFNB7/11 in 1 family with dominant and 10 families with recessive non-syndromic sensorineural hearing loss. In addition, mutation analysis of TMC1 was performed in 51 familial Turkish patients with autosomal recessive hearing loss. TMC1 mutations were identified in seven of the families segregating recessive hearing loss. The pathogenic variants we found included two known mutations, c.100C>T and c.1165C>T, and four new mutations, c.2350C>T, c.776+1G>A, c.767delT and c.1166G>A. The absence of TMC1 mutations in the remaining six linked families implies the presence of mutations outside the coding region of this gene or alternatively at least one additional deafness-causing gene in this region. The analysis of copy number variations in TMC1 as well as DNA sequencing of 15 additional candidate genes did not reveal any proven pathogenic changes, leaving both hypotheses open.

GW body disassembly triggered by siRNAs independently of their silencing activity

GW bodies (or P-bodies) are cytoplasmic granules containing proteins involved in both mRNA degradation and storage, including the RNA interference machinery. Their mechanism of assembly and function are still poorly known although their number depends upon the flux of mRNA to be stored or degraded. We show here that silencing of the translational regulator CPEB1 leads to their disappearance, as reported for other GW body components. Surprisingly, the same results were obtained with several siRNAs targeting genes encoding proteins unrelated to mRNA metabolism. The disappearance of GW bodies did not correlate with the silencing activity of the siRNA and did not inhibit further silencing by siRNA. Importantly, in most cases, GW bodies were rapidly reinduced by arsenite, indicating that their assembly was not prevented by the inhibition of the targeted or off-target genes. We therefore propose that some siRNA sequences affect mRNA metabolism so as to diminish the amount of mRNA directed to the GW bodies. As an exception, GW bodies were not reinduced following Rck/p54 depletion by interference, indicating that this component is truly required for the GW body assembly. Noteworthy, Rck/p54 was dispensable for the assembly of stress granules, in spite of their close relationship with the GW bodies.

Targets for global tuberculosis control

The United Nations Millennium Development Goals (MDGs) have added to the suite of targets and indicators used to evaluate progress in tuberculosis (TB) control. This paper reviews the history of target setting for TB control and lays out the complete set of indicators and targets that will guide TB control through to 2015, the target year for all MDGs.

Technical problems and complications of a transanal pull-through for Hirschsprung's disease

BACKGROUND

The purpose of this study was to evaluate the technical difficulties and complications of a transanal pull-through for Hirschsprung's disease.

MATERIAL AND METHODS

This report was based on a multicentric retrospective study of 65 cases. Pull-through procedures were transanal Swenson or Soave procedures in 26 and 39 cases, respectively.

RESULTS

Evaluation of the aganglionic level, peri-rectal dissection, and anastomosis were the three steps in the procedure where surgeons encountered difficulties. Such difficulties led to serious complications in 3 cases. A patient with a colon biopsy before the pull-through procedure had a postoperative pneumoperitoneum requiring a second laparoscopy for suture and washing. Another patient had peritonitis due to anastomotic leakage. Finally, a difficult rectal dissection in a neonate led to a urethral injury requiring secondary urethral repair. Only 41 of the 65 patients had no abdominal scars (63 %).

CONCLUSION

We considered the transanal pull-through for Hirschsprung's disease to be a reliable technique. Nevertheless, it requires an urethral stent, precise dissection, careful anastomosis and selected indications in order to avoid major complications.

The translational regulator CPEB1 provides a link between dcp1 bodies and stress granules

The cytoplasmic polyadenylation element-binding protein (CPEB) has been characterized in Xenopus laevis as a translational regulator. During the early development, it behaves first as an inhibitor and later as an activator of translation. In mammals, its closest homologue is CPEB1 for which two isoforms, short and long, have been described. Here we describe an additional isoform with a different RNA recognition motif, which is differentially expressed in the brain and ovary. We show that all CPEB1 isoforms are found associated with two previously described cytoplasmic structures, stress granules and dcp1 bodies. This association requires the RNA binding ability of the protein, whereas the Aurora A phosphorylation site is dispensable. Interestingly, the rck/p54 DEAD box protein, which is known as a CPEB partner in Xenopus and clam, and as a component of dcp1 bodies in mammals, is also present in stress granules. Both stress granules and dcp1 bodies are involved in mRNA storage and/or degradation, although so far no link has been made between the two, in terms of neither morphology nor protein content. Here we show that transient CPEB1 expression induces the assembly of stress granules, which in turn recruit dcp1 bodies. This dynamic connection between the two structures sheds new light on the compartmentalization of mRNA metabolism in the cytoplasm.

Treatment of thyroid associated ophthalmopathy with periocular injections of triamcinolone

AIM

To evaluate the efficacy of periocular triamcinolone acetonide for the treatment of thyroid associated ophthalmopathy (TAO), and the presence of ocular or systemic adverse effects.

METHODS

A multicentre prospective pilot study was performed on patients diagnosed with Graves' ophthalmopathy less than 6 months before entry to the study. Patients were admitted to the study and were randomised into two groups: treatment and control. The treatment group received four doses of 20 mg of triamcinolone acetate 40 mg/ml in a peribulbar injection to the inferolateral orbital quadrant. Both groups were evaluated by measuring the area of binocular vision without diplopia on a Goldmann perimeter and the size of the extraocular muscles on computed tomography (CT) scans. Ophthalmological and systemic examinations were done to rule out ocular and systemic adverse effects. Follow up was 6 months for both groups.

RESULTS

50 patients were eligible for the study. 41 patients completed the study. There was an increase in the area of binocular vision without diplopia in the treatment group (Sigma initial: mean 231.1 (SD 99.9) and final absolute change, mean 107.1 (SD 129.0)) compared to the control group (Sigma initial: mean 350.7 (SD 86.5) and final absolute change, mean -4.5 (SD 67.6)). The sizes of the extraocular muscles were reduced in the treatment group (mean (inferior rectus initial values): 1.3 (0.7), final percentage change: -13.2 (25.7), medial rectus initial values: 1.2 (0.6), final percentage change: -8.2 (20.7), superior rectus-levator palpebrae initial values: 1.2 (0.6), final percentage change: -9.5 (29.1), lateral rectus initial values: 1.0 (0.4), final percentage change: -11.5 (20.6)) compared to the control group (inferior rectus initial values: 0.9 (0.3), final percentage change: -4.0 (21.5), medial rectus initial values: 0.9 (0.3), final percentage change: 0.6 (22.4), superior rectus-levator palpebrae initial values: 0.9 (0.3), final percentage change: 12.5 (37.5), lateral rectus initial values: 0.9 (0.4), final percentage change: -0.5 (31.6)). Both measurements (degree of diplopia and muscle thickness) were statistically significant between groups (initial - final). No systemic or ocular adverse effects were found.

CONCLUSIONS

Triamcinolone administered as a periocular injection is effective in reducing diplopia and the sizes of extraocular muscles in TAO ophthalmopathy of recent onset. This form of treatment is not associated with systemic or ocular side effects.

Caecal volvulus in the Marden-Walker syndrome: an uncommon association of two rare diseases in a 4-year old child. Case report

The authors report a case of caecal volvulus associated with Marden-Walker syndrome in a 4-year old girl. They point out the diagnostic difficulties of this devastating disease specially in debilitated children.

Functional analysis of a dominant mutation of human connexin26 associated with nonsyndromic deafness

Cx26 has been implicated in dominant (DFNA3) and recessive (DFNB1) forms of nonsyndromic sensorineural deafness. While most homozygous DFNB1 Cx26 mutations result in a simple loss of channel activity, it is less clear how heterozygous mutations in Cx26 linked to DFNA3 cause hearing loss. We have tested the ability of one dominant mutation (W44C) to interfere with wild-type human Cx26 (HCx26wt). HCx26wt induced robust electrical conductance between paired oocytes, and facilitated dye transfer between transfected HeLa cells. In contrast, oocyte pairs injected with only W44C were not electrically coupled above background levels, and W44C failed to dye couple transfected HeLa cells. Moreover, W44C dramatically inhibited intercellular conductance of HCx26wt when co-expressed in an equal ratio, and the low levels of residual conductance displayed altered gating properties. A nonfunctional recessive mutation (W77R) did not inhibit the ability of HCx26wt to form functional channels when co-injected in the same oocyte pairs, nor did it alter HCx26wt gating. These results provide evidence for a functional dominant negative effect of the W44C mutant on HCx26wt and explain how heterozygous Cx26 mutations could contribute to autosomal dominant deafness, by resulting in a net loss, and/or alteration, of Cx26 function.

Targeting the kinesin Eg5 to monitor siRNA transfection in mammalian cells

RNA interference, the inhibition of gene expression by double-stranded RNA, provides a powerful tool for functional studies once the sequence of a gene is known. In most mammalian cells, only short molecules can be used because long ones induce the interferon pathway. With the identification of a proper target sequence, the penetration of the oligonucleotides constitutes the most serious limitation in the application of this technique. Here we show that a small interfering RNA (siRNA) targeting the mRNA of the kinesin Eg5 induces a rapid mitotic arrest and provides a convenient assay for the optimization of siRNA transfection. Thus, dose responses can be established for different transfection techniques, highlighting the great differences in response to transfection techniques of various cell types. We report that the calcium phosphate precipitation technique can be an efficient and cost-effective alternative to Oligofectamine in some adherent cells, while electroporation can be efficient for some cells growing in suspension such as hematopoietic cells and some adherent cells. Significantly, the optimal parameters for the electroporation of siRNA differ from those for plasmids, allowing the use of milder conditions that induce less cell toxicity. In summary, a single siRNA leading to an easily assayed phenotype can be used to monitor the transfection of siRNA into any type of proliferating cells of both human and murine origin.

In vivo kinetics of mRNA splicing and transport in mammalian cells

The kinetics of pre-mRNA processing in living cells is poorly known, preventing a detailed analysis of the regulation of these reactions. Using tetracycline-regulated promoters we performed, during a transcriptional induction, a complete analysis of the maturation of two cellular mRNAs, those for LT-alpha and beta-globin. In both cases, splicing was appropriately described by first-order reactions with corresponding half-lives ranging between 0.4 and 7.5 min, depending on the intron. Transport also behaved as a first-order reaction during the early phase of beta-globin expression, with a nuclear dwelling time of 4 min. At a later time, analysis was prevented by the progressive accumulation within the nucleus of mature mRNA not directly involved in export. Our results further establish for these genes that (i) splicing components are never limiting, even when expression is induced in naive cells, (ii) there is no significant RNA degradation during splicing and transport, and (iii) precursor-to-product ratios at steady state can be used for the determination of splicing rates. Finally, the comparison between the kinetics of splicing during transcriptional induction and during transcriptional shutoff reveals a novel coupling between transcription and splicing.

Valuing the economic consequences of work injury and illness: a comparison of methods and findings

BACKGROUND

Workplace injuries and fatalities in the US create significant economic costs to society. Although economic costs should measure the opportunity cost to society arising from injuries and fatalities, estimating them often proves difficult as a practical matter. This leads to a range of estimates for valuing these costs.

METHODS

This paper compares methods of economic valuation, focusing in particular on how different methods diverge to varying degrees from measuring the "true" economic costs of injuries and illnesses. In so doing, it surveys the literature that has arisen in the past 25 years to measure different aspects of economic consequences.

RESULTS

Estimates of the costs of injuries and fatalities tend to understate the true economic costs from a social welfare perspective, particularly in how they account for occupational fatalities and losses arising from work disabilities.

CONCLUSION

Although data availability often makes estimation of social welfare costs difficult, researchers should attempt to more fully integrate such approaches into estimation procedures and interpretation of their results.

Diseases of the lacrimal drainage system

We will refer to lacrimal system pathologies involving the outflow pathways, as well as to the recent advances in the management of canalicular and lacrimonasal duct anomalies, including modifications to dacrycystorhinostomy technique, treatment for congenital obstructions, and lacrimal intubations. Special emphasis will be placed on the usefulness of nasal and canalicular endoscopy for the examination and treatment of congenital obstructions and endonasal pathologies, as an aid for intubations and lacrimal surgery, as well as on reasons for failed procedures.

A specific promoter of the sensory cells of the inner ear defined by transgenesis

To date, no promoter sequence specific to the inner ear sensory cells (hair cells) has been reported. In an effort to understand the molecular mechanisms that determine hair cell fate in the inner ear, and with the goal of developing a valuable tool for gene therapy and for the generation of conditional knockouts, we initiated a search for cis-acting DNA sequences that regulate the expression of the murine Myo7a and human MYO7A genes. These genes encode the unconventional myosin VIIA which is expressed in hair cells and in some other epithelial cells. We generated lines of transgenic mice expressing the green fluorescent protein (GFP ) reporter gene under the control of several 5'-truncated versions of the Myo7a/MYO7A promoter region and intron 1. We obtained transgenic mice with a GFP expression restricted to the hair cells of the inner ear, cochlea and vestibule. Successive deletions of the promoter allowed us to define a minimal sequence of 118 bp that is sufficient, in the presence of intron 1, to target the transgene expression to hair cells. In addition, the deletion of intron 1 from the transgenes abolished hair cell expression, thus indicating the presence of a strong enhancer in the intron. This is the first report of regulatory sequences sufficient to target the expression of a gene exclusively in sensory cells of the inner ear. It also opens up the possibility for the analysis of the hair cell transcriptome.

[Traumatic luxation of the globe into the maxilar sinus]

PURPOSE

We present a case of traumatic luxation of the ocular globe into the maxillary sinus.

MATERIAL AND METHODS

Male patient, 23 years old with orbito-facial trauma and traumatic luxation of his right ocular globe into the maxillary sinus.

CONCLUSION

To present an unusual case of traumatic prolapse of an undamaged ocular globe into a paranasal sinus.

Laparoscopic adrenalectomy in children

BACKGROUND

The aim of this study was to describe the indications and results of laparoscopic adrenalectomy in children.

METHODS

This retrospective multicenter study included six children (four boys, two girls) aged 2-16 years (mean, 9.5). Three children had hypertension. In three cases, the adrenal mass was discovered incidentally. The tumors were bilateral in two children, right-sided in two cases, and left-sided in two cases. The mean tumor size was 4 cm (range, 1-7). Each child underwent MIBG scintigraphy and MRI before the operation.

RESULTS

Four right and two left adrenal glands were resected by laparoscopy (transperitoneal), and two left glands were resected by retroperitoneoscopy. Two conversions were necessary for two left adrenal glands (one retroperitoneoscopy, one laparoscopy). Two partial resections and six adrenalectomies were performed. Histological examination of the tumors revealed two ganglioneuromas, one neuroblastoma, and five pheochromocytomas (two bilateral). One child had an involved node (pheochromocytoma). Both bilateral pheochromocytomas had von Hippel-Lindau disease. There was no morbidity. Mean hospitalstay was 6 days. Postoperative evaluation at 1 month was normal in all children.

CONCLUSION

The indications for laparoscopic adrenalectomy in children are benign tumors and pheochromocytomas. In these cases, laparoscopic adrenalectomy is feasible and safe, even in cases of pheochromocytoma.

Internal drainage into an Onlay-Roux-en-Y jejunal loop in isolated pancreatic injury with ductal transection: short-term and long-term follow-up in two pediatric cases

Two pediatric cases of isolated pancreatic injury treated by internal drainage into an Onlay-Roux-en-Y jejunal loop are reported. The discussion concerns the difficulties of early diagnosis, the importance of endoscopic retrograde cholangiopancreatography (ERCP) in surgery and the reasons for the choice of internal drainage by Onlay-Roux-en-Y jejunal loop in our two cases.

Control your inventory in a world of lean retailing

As retailers adopt lean retailing practices, manufacturers are feeling the pinch. Retailers no longer place large seasonal orders for goods in advance-instead, they require ongoing replenishment of stock, forcing manufacturers to predict demand and then hold substantial inventories indefinitely. Manufacturers now carry the cost of inventory risk--the possibility that demand will dry up and goods will have to be sold below cost. And as product proliferation increases, customer demand becomes harder to predict. Most manufacturers apply one inventory policy for all stock-keeping units in a product line. But the inventory demand for SKUs within the same product line can vary significantly. SKUs with high volume typically have little variation in weekly sales, while slow-selling SKUs can vary enormously in weekly sales. The greater the variation, the larger the inventory the manufacturer must hold relative to an SKU's expected weekly sales. By differentiating inventory policies at the SKU level, manufacturers can reduce inventories for the high-volume SKUs and increase them for the low-volume ones--and thereby improve the profit-ability of the entire line. SKU-level differentiation can also be applied to sourcing strategies. Instead of producing all the SKUs for a product line at a single location, either offshore at low cost or close to market at higher cost, manufacturers can typically do better by going for a mixed allocation. Low-variation goods should be produced mainly offshore, while high-variation goods are best made close to markets.

Mature mRNAs accumulated in the nucleus are neither the molecules in transit to the cytoplasm nor constitute a stockpile for gene expression

In higher eukaryotes, the regulation of pre-mRNA processing is still poorly known. The accumulation of various mature mRNAs, which can be observed in the nuclei of mammalian cells, is suggestive of a regulatory role of transport. However, the significance of these nuclear mRNA is presently unknown. We have used a tetracycline-regulated promoter to investigate the dynamics of these pools of mRNAs upon arrest of transcription. We observed, for beta-globin and LT-alpha genes, a slow disappearance of these mRNA from the nucleus, with an apparent half-life that is similar to their cytoplasmic half-life. In view of these dynamics, these mRNA cannot simply be mature mRNAs in transit to the cytoplasm. They could be mRNAs retained in the nucleus, provided that the regulation of mRNA stability is comparable in the nucleus and the cytoplasm. But, because of their limited stability, these nuclear mRNAs cannot constitute a significant stock for gene expression. Alternatively, they could reflect a bidirectional transport of mRNA, that is, to and from the cytoplasm, which would provide a direct explanation for the similarity in both compartments of their half-life and poly(A) tail shortening over time.

Orbital leiomyoma: a case report

PURPOSE

Leiomyoma is a benign tumor derived from smooth muscle, most frequently occurring in the uterus and gastrointestinal system. This report discusses clinical and pathologic findings in a 56-year-old man with orbital leiomyoma.

METHODS

Case review.

RESULTS

A lateral orbitotomy was performed. Immunohistochemical staining for actin and desmin was positive result. There was no evidence of recurrence during a two-year follow-up interval.

CONCLUSIONS

Leiomyoma is a benign tumor of low incidence because there is little smooth muscle in the orbit. The differential diagnosis must include any fully encapsulated orbital tumor. Prognosis after surgical excision is favorable.

Accumulation of mature mRNA in the nuclear fraction of mammalian cells

Little is known about the nuclear mRNA content of mammalian cells. In this study, we analyzed by Northern blotting with a panel of probes the nuclear and cytoplasmic fractions derived from several rodent cell lines. For most of the genes under study, mature mRNAs could easily be detected in the nuclear fraction and accumulated to higher levels than the corresponding precursors. In addition, significant differences in the nucleo-cytoplasmic partition of mature mRNAs were observed between genes as well as between cell types (NIH 3T3, CTLL-2, D3-ES, PC-12), indicating that this nuclear accumulation of mRNA is regulated. Thus, while it is usually considered that splicing is the limiting step of pre-mRNA processing, these results point towards transport or nuclear retention of mRNA as a key determinant of nuclear mRNA metabolism.

Clinical features of the prevalent form of childhood deafness, DFNB1, due to a connexin-26 gene defect: implications for genetic counselling

BACKGROUND

DFNB1, the locus of an autosomal recessive form of deafness due to mutations in the connexin-26 gene (CX26 or GJB2) is one of the most frequent hereditary defects in human beings. To date, no clinical characterisation of the DFNB1 inner-ear defects has been reported, which precludes the provision of prognostic information and genetic counselling.

METHODS

We enrolled, in a prospective study, 140 children from 104 families affected by sensorineural deafness with various degrees of hearing loss. The children either belonged to a family affected by autosomal recessive deafness (DFNB family) or represented sporadic cases. We searched for mutations in the 5' non-coding exon and in the coding region of CX26. Audiometric and radiological features were investigated and compared in deaf children with and without CX26 mutations.

FINDINGS

CX26 mutations were present in 43 (49%) of the 88 families with cases of prelingual deafness versus none of the 16 families with postlingual forms of deafness (p<0.01). The inner-ear defects of 54 prelingually deaf children with biallelic CX26 mutations were compared with the defects in 57 prelingually deaf children without CX26 mutations. DFNB1 deafness varied from mild to profound, associated with sloping or flat audiometric curves and a radiologically normal inner ear. Hearing loss was not progressive in 11 of 16 cases tested, and variations in the severity of deafness between siblings were common.

INTERPRETATION

The characteristic audiometric and radiological features of DFNB1 should be the reference used to guide the investigation, by CX26 molecular diagnostic tests, of deaf children with a compatible phenotype. Prognostic information can now be given to families: the hearing loss in DFNB1 deafness is non-progressive in most cases, at least up to young adulthood. An important element for genetic counselling is that the severity of hearing loss due to DFNB1 is extremely variable and cannot be predicted, even within families.

An alpha-tectorin gene defect causes a newly identified autosomal recessive form of sensorineural pre-lingual non-syndromic deafness, DFNB21

In our efforts to identify new loci responsible for non-syndromic autosomal recessive forms of deafness, DFNB loci, we have pursued the analysis of large consanguineous affected families living in geographically isolated areas. Here, we report on the study of a Lebanese family comprising nine members presenting with a pre-lingual severe to profound sensorineural isolated form of deafness. Linkage analysis led to the characterization of a new locus, DFNB21, which was assigned to chromosome 11q23-25. Already mapped to this chromosomal region was TECTA. This gene encodes alpha-tectorin, a 2155 amino acid protein which is a component of the tectorial membrane. This gene recently has been shown to be responsible for a dominant form of deafness, DFNA8/12. Sequence analysis of the TECTA gene in the DFNB21-affected family revealed a G to A transition in the donor splice site (GT) of intron 9, predicted to lead to a truncated protein of 971 amino acids. This establishes that alpha-tectorin mutations can be responsible for both dominant and recessive forms of deafness. Comparison of the phenotype of the DFNB21 heterozygous carriers with that of DFNA8/12-affected individuals supports the hypothesis that the TECTA mutations which cause the dominant form of deafness have a dominant-negative effect. The present results provide genetic evidence for alpha-tectorin forming homo- or heteromeric structures.

Complications employing the holmium:YAG laser

We report the operative and early postoperative complications and limitations in 133 patients treated with the holmium laser. Complications included urinary tract infection (N = 3), postoperative bradycardia (1), inverted T-waves (1), intractable flank pain (1), urinary retention (1), inability to access a lower-pole calix with a 365-microm fiber (9), stone migration (5), and termination of procedure because of poor visibility (2). No ureteral perforations or strictures occurred, and no complications were directly attributable to the laser. The holmium laser was capable of fragmenting all urinary calculi in this study. In our initial experience, the holmium laser is safe and effective in the treatment of urinary pathology. Use of laser fibers larger than 200 microm occasionally limits deflection of the endoscope into a lower-pole or dependent calix.

Identification of a locus on chromosome 7q31, DFNB14, responsible for prelingual sensorineural non-syndromic deafness

In our efforts to identify new loci responsible for non-syndromic autosomal recessive forms of deafness, DFNB loci, we have pursued the analysis of large consanguineous affected families living in geographically isolated areas. Here, we report on the study of a Lebanese family affected with a prelingual profound sensorineural isolated form of deafness. Segregation analysis resulted in a linkage with locus D7S554 to locus D7S2459 on 7q31, with a maximum lod score of 6.3. The causative gene was mapped to a 15 cM interval extending from D7S527 to D7S3074 (on the telomeric side). The distal limit of this interval could be located between D7S496 and D7S3074 which are the closest polymorphic loci flanking the gene underlying Pendred syndrome (PDS) on the centromeric and on the telomeric sides, respectively. To eliminate PDS as a candidate gene, its 21 exons were sequenced. No mutation was detected. This study therefore reports the identification of a novel locus, DFNB14, on chromosome 7q31, in a position proximal to PDS.

Unilocular hydatid cyst of the kidney in a child: a diagnostic challenge

A case of an unilocular renal hydatid cyst in a 10-year-old French girl without any notion of travelling in a foreign country is reported. In children affected by renal echinococcosis, clinical symptoms and physical examination are nonspecific. Among the diagnostic procedures, the role of echography in the assessment of the diagnosis is pointed out.

Expression of the Wilms' tumor suppressor gene, WT1, is upregulated by leukemia inhibitory factor and induces monocytic differentiation in M1 leukemic cells

The Wilms' tumor gene, WT1, encodes a transcription factor of the Cys2-His2 zinc finger type. The functional significance of WT1 expression in leukemias, in addition to tissues and cell lines of hematopoietic origin, has not been determined. Using the murine myeloblastic leukemia cell line M1 as a model for macrophage differentiation, expression of WT1 is shown to be activated in M1 cells 24 hours after differentiation induction by leukemia inhibitory factor (LIF). Upregulation of WT1 in these cells is associated with cellular differentiation, coinciding with expression of the monocyte/macrophage marker c-fms, and the appearance of mature cells. WT1 isoforms lacking the KTS insert are unable to be ectopically expressed in M1 cells. Stable expression of the WT1 isoforms containing the KTS insert leads to spontaneous differentiation of the M1 myeloblasts through the monocytic differentiation pathway. These cells express c-fms, in addition to the myeloid-specific cell surface marker Mac-1. Exposure of these cells to LIF results in the rapid onset of terminal macrophage differentiation, accompanied by apoptotic cell death. These results show that the WT1 gene is an important regulator of M1 cell monocytic differentiation in vitro, and suggests a potential role for this gene in the molecular control of hematopoiesis.

Sequence characterization of a newly identified human alpha-tubulin gene (TUBA2)

We report on the isolation and initial characterization of a human alpha-tubulin gene named TUBA2. This gene is located in the 13q11 region and has been considered a candidate gene for two nonsyndromic deafnesses, DFNB1 and DFNA3. The gene, with a minimum size of 6.5 kb, contains five exons and four introns starting at codon positions 1, 76, 125, and 352, one of which is inserted between the initiation methionine codon and the codon specifying the second amino acid, arginine 2. Neither rearrangement nor point mutation was found in the coding region of the gene in DFNB1- and DFNA3-affected patients. The gene was therefore unlikely to be responsible for either of these deafnesses. During the characterization of TUBA2, the gene encoding connexin 26 was proven to be responsible for both DFNB1 and DFNA3 (D. P. Kelsell et al., 1997, Nature 387: 80-83). However, the present data offer the possibility of testing the involvement of the TUBA2 gene in the Clouston hidrotic ectodermal dysplasia and the Kabuki syndrome, two genetic diseases that have recently been mapped to the 13q11 region.

Predominant expression of murine Bmx tyrosine kinase in the granulo-monocytic lineage

In the course of systematic cloning of protein tyrosine kinases (PTKs) expressed in hematopoietic stem and progenitor cells, we have identified the murine homologue of human Bmx. It encodes a protein containing the five domains characteristic of the Tec family of cytoplasmic src-related PTKs: pleckstrin homology (PH), Tec homology (TH), src homology 3 and 2 (SH3 and SH2), and tyrosine kinase (TK). In adults, Bmx expression was found primarily in bone marrow and at a lower level in lung and heart. During fetal development it was also found in the spleen at late stage of gestation and in neonates. Analysis of bone marrow subpopulations showed that Bmx was expressed in the progenitor cell population and maturing hematopoietic cells of the granulo/monocytic lineage where expression increased with maturation and differentiation. At the periphery, a high level of Bmx expression was also found in neutrophils and monocytes/macrophages. Bmx expression was not detected in the primitive hematopoietic stem cell population, and cells of the B-, T-, and erythroid-lineages. It was also not detected in most of the cell lines examined. Our results indicate that Bmx is another member of the Btk/Itk/Tec PTK family, which is predominantly expressed in the granulo-monocytic lineage within the hematopoietic system.

Clustering of mutations responsible for branchio-oto-renal (BOR) syndrome in the eyes absent homologous region (eyaHR) of EYA1

Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder, characterised by the association of branchial, otic and renal anomalies with variable degrees of severity. We have recently identified EYA1 , a human homologue of the Drosophila eyes absent gene, as the gene underlying this syndrome. The products of both genes share a highly conserved 271 amino acid C-terminal region (eyaHR). The eyaHR was also found in the products of two other human genes (EYA2 and EYA3), demonstrating the existence of a novel gene family. We report here on the complete genomic structure of EYA1. This gene consists of 16 coding exons and extends over 156 kb. It encodes various alternatively spliced transcripts differing only in their 5' regions. Sequence analysis of the entire EYA1 coding region was performed for 20 unrelated patients affected by BOR syndrome, and six novel mutations were identified. Among these mutations, two are missense mutations, highlighting amino acid residues essential for the function of the EYA1 protein, and one mutation comprises a de novo Alu insertion into an exon. This insertion presumably occurs by retrotransposition, and the mobile Alu element has a poly(A) tail that is unstable throughout generations. To date, 14 mutations have been detected in BOR patients, all of which are different. However, all the mutations are located within or in the immediate vicinity of the eyaHR; the significance of this clustering is discussed.

Prelingual deafness: high prevalence of a 30delG mutation in the connexin 26 gene

Prelingual non-syndromic (isolated) deafness is the most frequent hereditary sensory defect. In >80% of the cases, the mode of transmission is autosomal recessive. To date, 14 loci have been identified for the recessive forms (DFNB loci). For two of them, DFNB1 and DFNB2, the genes responsible have been characterized; they encode connexin 26 and myosin VIIA, respectively. In order to evaluate the extent to which the connexin 26 gene (Cx26) contributes to prelingual deafness, we searched for mutations in this gene in 65 affected Caucasian families originating from various countries, mainly tunisia, France, New Zealand and the UK. Six of these families are consanguineous, and deafness was shown to be linked to the DFNB1 locus, 10 are small non consanguineous families in which the segregation of the trait has been found to be compatible with the involvement of DFNB1, and in the remaining 49 families no linkage analysis has been performed. A total of 62 mutant alleles in 39 families were identified. Therefore, mutations in Cx26 represent a major cause of recessively inherited prelingual deafness since according to the present results they would underlie approximately half of the cases. In addition, one specific mutation, 30delG, accounts for the majority (approximately 70%) of the Cx26 mutant alleles. It is therefore one of the most frequent disease mutations so far identified. Several lines of evidence indicate that the high prevalence of the 30delG mutation arises from a mutation hot spot rather than from a founder effect. Genetic counseling for prelingual deafness has been so far considerably impaired by the difficulty in distinguishing genetic and non genetic deafness in families presenting with a single deaf child. Based on the results presented here, the development of a simple molecular test could be designed which should be of considerable help.