Interacting genes in nematode dauer larva formation

The dauer larva of Caenorhabditis elegans is a developmentally arrested stage induced by starvation or overcrowding. Mutant genes controlling the ability to form dauer larvae interact in a way which allows them to be ordered in a pathway. Mutant phenotypes suggest that the pathway corresponds to neural processing of environmental stimuli.

Hereditary haemorrhagic telangiectasia: a clinical analysis

Data from 98 patients with hereditary haemorrhagic telangiectasia (HHT) are presented. All were symptomatic by 40 years of age and 62% by 16 years. Nose bleeding was the first symptom of disease in 90% of cases with mucocutaneous telangiectases appearing 5 to 20 years later. Complications of HHT are discussed and an age of onset curve given.

Hereditary hemorrhagic telangiectasia: from molecular biology to patient care

SUMMARY

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder characterized by severe and recurrent nosebleeds, mucocutaneous telangiectases, and, in some cases, life-threatening visceral arteriovenous malformations of various types, including pulmonary, hepatic, cerebral, and spinal. Gastrointestinal telangiectases are frequent and may cause severe bleeding. HHT type 1 results from mutations in ENG on chromosome 9 (coding for endoglin), and HHT type 2 results from mutations in ACVRL1 on chromosome 12 (coding for activin receptor-like kinase 1). Mutations of either of these two genes account for most clinical cases. In addition, mutations in MADH4 (encoding SMAD4), which cause a juvenile polyposis/HHT overlap syndrome, have been described, and recently, an HHT3 locus on chromosome 5 (5q31.3-5q32) has been reported. The mutated genes in HHT encode proteins that modulate transforming growth factor-beta superfamily signaling in vascular endothelial cells. Management of patients has changed considerably in the last 20 years, in terms of both treatment and the prevention of complications. The goal of this review was to describe the underlying molecular and cellular physiopathology, explore clinical and genetic diagnostic strategies for HHT, and present clinical management recommendations in order to treat symptomatic disease and to screen for vascular malformations.

Sinonasal undifferentiated carcinoma: a 10-year experience

PURPOSE

Sinonasal undifferentiated carcinoma (SNUC) is a rare and aggressive malignancy of the paranasal sinuses and nasal cavity. Of the few reported series, most indicate a dismal prognosis. In this report, the clinical presentation, histopathologic criteria used for diagnosis, mode of treatment, and outcome are evaluated in seven patients with SNUC.

MATERIALS AND METHODS

Seven patients with SNUC treated at the University of Cincinnati between 1983 and 1993 were analyzed retrospectively.

RESULTS

Most of the patients presented with extensive local disease, and two patients also had cervical metastases. All except one were treated using a multimodality approach. Four of the seven patients died of disease (DOD), with a mean survival of only 11.5 months following treatment. Inability to eradicate local disease was responsible for treatment failure in all cases. Three patients have achieved short-term control of disease following combined therapy, but one is at high risk for recurrence.

CONCLUSION

SNUC was associated with an overall poor prognosis in our series despite aggressive treatment. Control of local disease was the central therapeutic consideration. Intensive multimodality therapy is recommended for all patients with SNUC.

Seroprevalence of antibodies against Bartonella species and evaluation of risk factors and clinical signs associated with seropositivity in dogs

OBJECTIVE

To determine the seroprevalence of antibodies against Bartonella spp in a population of sick dogs from northern California and identify potential risk factors and clinical signs associated with seropositivity.

SAMPLE POPULATION

Sera from 3,417 dogs.

PROCEDURE

Via an ELISA, sera were analyzed for antibodies against Bartonella vinsonii subsp berkhoffii, Bartonella clarridgeiae, and Bartonella henselae; test results were used to classify dogs as seropositive (mean optical density value > or = 0.350 for B henselae or > or = 0.300 for B clarridgeiae or B vinsonii subsp berkhoffi) or seronegative. Overall, 305 dogs (102 seropositive and 203 seronegative dogs) were included in a matched case-control study.

RESULTS

102 of 3,417 (2.99%) dogs were seropositive for > or = 1 species of Bartonella. Of these, 36 (35.3%) had antibodies against B henselae only, 34 (33.3%) had antibodies against B clarridgeiae only, 2 (2.0%) had antibodies against B vinsonii subsp berkhoffii only, and 30 (29.4%) had antibodies against a combination of those antigens. Compared with seronegative dogs, seropositive dogs were more likely to be herding dogs and to be female, whereas toy dogs were less likely to be seropositive. Seropositive dogs were also more likely to be lame or have arthritis-related lameness, nasal discharge or epistaxis, or splenomegaly.

CONCLUSIONS AND CLINICAL RELEVANCE

Only a small percentage of dogs from which serum samples were obtained had antibodies against Bartonella spp. Breed appeared to be an important risk factor for seropositivity. Bartonella infection should be considered in dogs with clinical signs of lameness, arthritis-related lameness, nasal discharge or epistaxis, or splenomegaly.

Effect of Bevacizumab Nasal Spray on Epistaxis Duration in Hereditary Hemorrhagic Telangectasia: A Randomized Clinical Trial

BACKGROUND

Epistaxis is the most frequent and disabling manifestation of hereditary hemorrhagic telangiectasia (HHT). The efficacy of intravenous bevacizumab (an anti-vascular endothelial growth factor monoclonal antibody) for epistaxis has been shown. However, the efficacy of intranasal bevacizumab has yet to be evaluated.

OBJECTIVE

To evaluate the efficacy of 3 different doses of bevacizumab administered as a nasal spray in a repeated manner for the duration of nosebleeds in patients with HHT.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, multicenter, placebo-controlled, phase 2/3 clinical trial with dose selection at an intermediate analysis and prespecified stopping rules (nonbinding stopping for futility). Patients aged 18 years or older with a diagnosis of HHT were recruited from 5 French centers from April 2014 to January 2015 with a 6-month follow-up after the end of treatment. Participants had a history of self-reported nosebleeds with a monthly duration of more than 20 minutes in at least the 3 months prior to inclusion corroborated by epistaxis grids completed during the same preinclusion period.

INTERVENTIONS

Eighty consecutive HHT patients were randomized and treated in the phase 2 study, with 4 parallel groups in a 1:1:1:1 ratio. One group received placebo (n = 21); the other 3 received bevacizumab nasal spray. Each bevacizumab group received a different dose of the drug (25 mg [n = 20], 50 mg [n = 20], or 75 mg [n = 19] per treatment) in 3 doses 14 days apart for a total treatment duration of 4 weeks, resulting in a total dose of 75 mg, 150 mg, and 225 mg in each treatment group.

MAIN OUTCOMES AND MEASURES

Mean monthly epistaxis duration for 3 consecutive months immediately after the end of the treatment.

RESULTS

Of the 80 patients who were randomized (mean age, 60.47 [SD, 10.61] years; 37 women [46.25%]), 75 completed the study. Mean monthly epistaxis duration measured at 3 months was not significantly different in the 59 patients receiving bevacizumab in comparison with the placebo group (P = .57) or between the bevacizumab groups. The mean monthly epistaxis duration was 259.2 minutes (95% CI, 82.1-436.3 minutes) in the 25-mg group, 244.0 minutes (95% CI, 81.8-406.2 minutes) in the 50-mg group, 215.0 minutes (95% CI, 102.8-327.2 minutes) in the 75-mg group, and 200.4 minutes (95% CI, 109.3-291.5 minutes) in the placebo group. Toxicity was low and no severe adverse events were reported. This study was terminated prior to phase 3 for treatment futility after interim analysis on the recommendations of an independent data monitoring committee.

CONCLUSIONS AND RELEVANCE

In patients with HHT, a bevacizumab nasal spray treatment of 3 administrations at 14-day intervals with doses of 25 mg, 50 mg, or 75 mg per spray, compared with a placebo, did not reduce monthly epistaxis duration in the 3 consecutive months immediately after the end of treatment.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02106520.

Spinal cord arteriovenous malformations in two patients with hereditary hemorrhagic telangiectasia

We report two cases, in first cousins, of spinal arteriovenous malformations (AVMs) of the perimedullary fistula type and hereditary hemorrhagic telangiectasia (HHT). Spinal AVMs are a rare clinical presentation of HHT, but can be the first manifestation in a child with this disorder. The importance of considering a coexisting disorder of vascular dysplasia, such as HHT, when a child presents with a spinal AVM is discussed.

Estimating quantitative genetic parameters in haplodiploid organisms

Haplodiploid organisms (diploid females and haploid males) are genetically distinct in that they have asymmetrical genetic segregation, gene dosage compensation in the haploid male, maternal effects, and a general propensity to inbreed. Taking these characteristics into account, we demonstrate how conventional experimental designs and statistics derived to measure quantitative genetic parameters for diploid organisms can be applied to haplodiploid ones. First, the C matrix of the joint-scaling test is modified to test the additive-dominance model and then the calculations for fractions in the C matrices (for males and females) are shown for an infinite number of generations with both random and brother-sister mating. Second, analytical adjustments are outlined for the derivation of covariance between relatives using populations at either Hardy-Weinberg equilibrium or those that prefer to inbreed. Finally, four of the conventional designs (sib-analysis, offspring-parental regression, North Carolina III (NC III), and diallel cross) are modified and then compared according to their ability to deal with the experimental conditions encountered in haplodiploid systems. Although all designs can be used with caution, our analysis suggests that the NC III design is the most broadly applicable because it consistently meets the theoretical assumptions. The parameters we derive here for inbred populations are recommended for analysing the typically skewed genotypic distributions found in many natural populations of haplodiploid organisms. The theoretical and applied aspects of our work as well as the difference between our work and that for X-linked genes are discussed.

An insertion mutation associated with constitutive expression of repressible acid phosphatase in Saccharomyces cerevisiae

The PHO83 mutation in Saccharomyces cerevisiae, which had been detected on the basis of constitutive production of repressible acid phosphatase and mapped at the end of the PHO5 locus, was analysed by Southern hybridization with cloned DNA fragments of the PHO5 gene as probe. It was shown that this mutant has a DNA insertion of about 6 kilobase pairs, probably in the 5'-noncoding region of the PHO5 gene. Production of repressible acid phosphatase by the PHO83 mutant is partially independent of the function of the PHO2 and PHO4 genes, the positive regulatory genes whose functions are indispensable for PHO5 expression. PHO83 mutants are constitutive in a and alpha cells, either haploid or diploid, but not in non-mating cells, MATa/MAT alpha or a certain sterile mutation. These observations strongly suggest that the PHO83 mutation is caused by insertion of a Ty element in the 5'-noncoding region of the PHO5 gene.