Mohammed M. Youssef

VAX1 Mutation Associated with Microphthalmia, Corpus Callosum Agenesis, and Orofacial Clefting: The First Description of a VAX1 Phenotype in Humans

Vax1 and Vax2 have been implicated in eye development and the closure of the choroid fissure in mice and zebrafish. We sequenced the coding exons of VAX1 and VAX2 in 70 patients with anophthalmia/microphthalmia (A/M). In VAX1, we observed homozygosity for two successive nucleotide substitutions c.453G>A and c.454C>A, predicting p.Arg152Ser, in a proband of Egyptian origin with microphthalmia, small optic nerves, cleft lip/palate, and corpus callosum agenesis. This mutation affects an invariant residue in the homeodomain of VAX1 and was absent from 96 Egyptian controls. It is likely that the mutation results in a loss of function, as the mutation results in a phenotype similar to the Vax1 homozygous null mouse. We did not identify any mutations in VAX2. This is the first description of a phenotype associated with a VAX1 mutation in humans and establishes VAX1 as a new causative gene for A/M. Hum Mutat 33:364–368, 2012.

Virucidal Effect of Cold Atmospheric Gaseous Plasma on Feline Calicivirus, a Surrogate for Human Norovirus

ABSTRACT Minimal food-processing methods are not effective against foodborne viruses, such as human norovirus (NV). It is important, therefore, to explore novel nonthermal technologies for decontamination of foods eaten fresh, minimally processed and ready-to-eat foods, and food contact surfaces. We studied the in vitro virucidal activity of cold atmospheric gaseous plasma (CGP) against feline calicivirus (FCV), a surrogate of NV. Factors affecting the virucidal activity of CGP (a so-called radio frequency atmospheric pressure plasma jet) were the plasma generation power, the exposure time and distance, the plasma feed gas mixture, and the virus suspension medium. Exposure to 2.5-W argon (Ar) plasma caused a 5.55 log10 unit reduction in the FCV titer within 120 s. The reduction in the virus titer increased with increasing exposure time and decreasing exposure distance. Of the four plasma gas mixtures studied (Ar, Ar plus 1% O2, Ar plus 1% dry air, and Ar plus 0.27% water), Ar plus 1% O2 plasma treatment had the highest virucidal effect: more than 6.0 log10 units of the virus after 15 s of exposure. The lowest virus reduction was observed with Ar plus 0.27% water plasma treatment (5 log10 unit reduction after 120 s). The highest reduction in titer was observed when the virus was suspended in distilled water. Changes in temperature and pH and formation of H2O2 were not responsible for the virucidal effect of plasma. The oxidation of viral capsid proteins by plasma-produced reactive oxygen and nitrogen species in the solution was thought to be responsible for the virucidal effect. In conclusion, CGP exhibits virucidal activity in vitro and has the potential to combat viral contamination in foods and on food preparation surfaces.

Post-traumatic posterior urethral stricture in children: How to achieve a successful repair

OBJECTIVE Complex post-traumatic posterior urethral strictures in children constitute a major challenge to the pediatric urologist. Surgical repair depends primarily on the length of the urethral obliteration. Resection with end-to-end anastomosis is the usual procedure in the face of a short segment stricture. Transpubic urethroplasty and substitution urethroplasty are currently used to treat extensive and complex urethral strictures. We present our experience of the management of children presenting with post-traumatic posterior urethral stricture. PATIENTS AND METHODS Fifty boys with a mean age of 9 years (6-13) with obliterative urethral stricture were operated on during May 1999 to August 2006. Short posterior urethral stricture was treated by excision and end-to-end anastomotic urethroplasty in 40 boys. Long posterior urethral stricture was managed by combined inferior pubectomy in three, transpubic urethroplasty in four and tubed penile fasciocutaneous flap in three. RESULTS With a mean follow-up of 4.5 years (6 months-7 years), all children who underwent perineal anastomotic urethroplasty were successfully repaired. Transpubic urethroplasty was associated with a re-stricture in one child 6 years following the repair. In the group repaired by tubed fasciocutaneous flap, we encountered a distal anastomotic stricture accompanied by a huge proximal diverticulum which needed revision in one child, and another diverticulum with multiple stones in another who was treated successfully. CONCLUSION Anastomotic urethroplasty in children is feasible with good results. Proper evaluation is needed to choose the best surgical technique for each patient. Tubed fasciocutaneous flap carries the highest complication rate.

Amino acid composition and In Vitro digestibility of some Egyptian foods made from faba bean (Vicia faba L)

Abstract Faba beans were cooked to prepare four different dishes—Medammis, Falafel, Bissara and Nabet Soup—that are widely consumed in many Middle Eastern Countries, especially in Egypt. Amino acid composition and in vitro digestibility were determined and compared to raw beans. Severe heat-processing markedly decreased some essential amino acids, especially phenylalanine, cystine, methionine and tryptophan. Protein scores were 38·1, 21·2, 39·3, 33·7 and 42·4 for raw faba beans, Medammis, Falafel, Bissara and Nabet Soup, respectively. Cooking resulted in an appreciable increase in the in vitro digestibility which amounted to 98·4% for Nabet Soup, being close to that of casein (99·6%). The in vitro digestibility values were 75·9%, 92·7%, 85·0% and 97·2% for raw beans, Medammis, Falafel and Bissara, respectively.

Antiviral Effects of Lactococcus lactis on Feline Calicivirus, A Human Norovirus Surrogate.

AbstractFoodborne viruses, particularly human norovirus (NV) and hepatitis virus type A, are a cause of concern for public health making it necessary to explore novel and effective techniques for prevention of foodborne viral contamination, especially in minimally processed and ready-to-eat foods. This study aimed to determine the antiviral activity of a probiotic lactic acid bacterium (LAB) against feline calicivirus (FCV), a surrogate of human NV. Bacterial growth medium filtrate (BGMF) of Lactococcus lactis subsp. lactis LM0230 and its bacterial cell suspension (BCS) were evaluated separately for their antiviral activity against FCV grown in Crandell–Reese feline kidney (CRFK) cells. No significant antiviral effect was seen when CRFK cells were pre-treated with either BGMF (raw or pH 7-adjusted BGMF) or BCS. However, pre-treatment of FCV with BGMF and BCS resulted in a reduction in virus titers of 1.3 log10 tissue culture infectious dose (TCID)50 and 1.8 log10 TCID50, respectively. The highest reductions in FCV infectivity were obtained when CRFK cells were co-treated with FCV and pH 7-adjusted BGMF or with FCV and BCS (7.5 log10 TCID50 and 6.0 log10 TCID50, respectively). These preliminary results are encouraging and indicate the need for continued studies on the role of probiotics and LAB on inactivation of viruses in various types of foods.

Mutations in ALDH1A3 Represent a Frequent Cause of Microphthalmia/Anophthalmia in Consanguineous Families

Anophthalmia or microphthalmia (A/M), characterized by absent or small eye, can be unilateral or bilateral and represent developmental anomalies due to the mutations in several genes. Recently, mutations in aldehyde dehydrogenase family 1, member A3 (ALDH1A3) also known as retinaldehyde dehydrogenase 3, have been reported to cause A/M. Here, we screened a cohort of 75 patients with A/M and showed that mutations in ALDH1A3 occurred in six families. Based on this series, we estimate that mutations in ALDH1A3 represent a major cause of A/M in consanguineous families, and may be responsible for approximately 10% of the cases. Screening of this gene should be performed in a first line of investigation, together with SOX2.

In Vitro Antiviral Activity of Clove and Ginger Aqueous Extracts against Feline Calicivirus, a Surrogate for Human Norovirus.

Foodborne viruses, particularly human norovirus, are a concern for public health, especially in fresh vegetables and other minimally processed foods that may not undergo sufficient decontamination. It is necessary to explore novel nonthermal techniques for preventing foodborne viral contamination. In this study, aqueous extracts of six raw food materials (flower buds of clove, fenugreek seeds, garlic and onion bulbs, ginger rhizomes, and jalapeño peppers) were tested for antiviral activity against feline calicivirus (FCV) as a surrogate for human norovirus. The antiviral assay was performed using dilutions of the extracts below the maximum nontoxic concentrations of the extracts to the host cells of FCV, Crandell-Reese feline kidney (CRFK) cells. No antiviral effect was seen when the host cells were pretreated with any of the extracts. However, pretreatment of FCV with nondiluted clove and ginger extracts inactivated 6.0 and 2.7 log of the initial titer of the virus, respectively. Also, significant dosedependent inactivation of FCV was seen when host cells were treated with clove and ginger extracts at the time of infection or postinfection at concentrations equal to or lower than the maximum nontoxic concentrations. By comprehensive two-dimensional gas chromatography-mass spectrometry analysis, eugenol (29.5%) and R-(-)-1,2-propanediol (10.7%) were identified as the major components of clove and ginger extracts, respectively. The antiviral effect of the pure eugenol itself was tested; it showed antiviral activity similar to that of clove extract, albeit at a lower level, which indicates that some other clove extract constituents, along with eugenol, are responsible for inactivation of FCV. These results showed that the aqueous extracts of clove and ginger hold promise for prevention of foodborne viral contamination.

Cold argon-oxygen plasma species oxidize and disintegrate capsid protein of feline calicivirus

Possible mechanisms that lead to inactivation of feline calicivirus (FCV) by cold atmospheric-pressure plasma (CAP) generated in 99% argon-1% O2 admixture were studied. We evaluated the impact of CAP exposure on the FCV viral capsid protein and RNA employing several cultural, molecular, proteomic and morphologic characteristics techniques. In the case of long exposure (2 min) to CAP, the reactive species of CAP strongly oxidized the major domains of the viral capsid protein (VP1) leading to disintegration of a majority of viral capsids. In the case of short exposure (15 s), some of the virus particles retained their capsid structure undamaged but failed to infect the host cells in vitro. In the latter virus particles, CAP exposure led to the oxidation of specific amino acids located in functional peptide residues in the P2 subdomain of the protrusion (P) domain, the dimeric interface region of VP1 dimers, and the movable hinge region linking the S and P domains. These regions of the capsid are known to play an essential role in the attachment and entry of the virus to the host cell. These observations suggest that the oxidative effect of CAP species inactivates the virus by hindering virus attachment and entry into the host cell. Furthermore, we found that the oxidative impact of plasma species led to oxidation and damage of viral RNA once it becomes unpacked due to capsid destruction. The latter effect most likely plays a secondary role in virus inactivation since the intact FCV genome is infectious even after damage to the capsid.