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A Hadidi

Publications and source records attributed to A Hadidi.

At least 19 recordsLinked to original sources
PubMed2003

Transanal endorectal pull-through for Hirschsprung's disease: experience with 68 patients.

BACKGROUND/PURPOSE: The aim of this study was to evaluate the indications, results, and complications of transanal endorectal pull-through (TEPT) in the management of recto-sigmoid Hirschsprung's disease (HD). METHODS: Between November 1998 and March 2002, 68 TEPT procedures were performed in infants and children. The patients' ages ranged from 6 days to 13 years. The primary diagnosis in all 68 patients was Hirschsprung's disease confined to the recto-sigmoid region. All children had their operations done without construction of preoperative colostomy except for one. Follow-up period ranged from 3 to 39 months (mean, 21 months). RESULTS: The mean operating time was 90 minutes, and average length of bowel resected was 25 cm. Sixty-two patients had satisfactory results without complications. Blood transfusion was needed in only 11 patients. Recovery was very fast, and patients often were hungry within 24 hours. Feeding was resumed within 48 hours. One patient required laparotomy during the procedure owing to injury to the urethra. Two patients required colostomy 3 and 5 days after surgery respectively, because of delayed leakage. Three patients suffered from attacks of enterocolitis 6 to 9 months postoperatively. There was increased frequency of defecation (5 to 15 times daily) for 4 to 6 weeks after surgery in all the patients. There was no constipation, no incontinence, no cuff abscess, and no mortality in any of the patients. Average frequency of defecation was 1 to 3 times daily after 3 months. The cost of the TEPT technique was almost half that of the open surgery. CONCLUSIONS: TEPT takes less time, has less bleeding, shorter hospital stay, less morbidity, and earlier recovery than similar open pull-through procedures. The hazards and morbidities associated with laparotomy and colostomy may be avoided with a one-stage technique in Hirschsprung's disease confined to the recto-sigmoid region. Careful long-term follow-up is required to assess continence and sexual function.

Child↗
PubMed2003

Transanal endorectal pull-through for Hirschsprung's disease: a comparison with the open technique.

AIM: To evaluate the indications, results, and complications of Transanal Endorectal Pull-Through (TEPT) in the management of rectosigmoid Hirschsprung's disease (HD) compared with the open technique. PATIENTS AND METHODS: Between November 1998 and March 2002, 68 Transanal Endorectal Pull-Through (TEPT) procedures were performed in infants and children. The patients' ages ranged from 6 days to 13 years. The primary diagnosis in all 68 patients was Hirschsprung's disease confined to the rectosigmoid region. All children were operated without construction of a pre-operative colostomy except for one patient. Follow-up period ranged from 6 - 46 months (mean 32 months). These patients were compared with fifty patients who had undergone open pull-through for HD during the period from November 1995 to October 1998. RESULTS AND COMPLICATIONS: For the TEPT group, the mean operating time was 90 min and the average length of resected bowel was 25 cm. Sixty-two patients had satisfactory results without complications. Blood transfusion was needed in eleven patients only. Recovery was very fast and patients were often hungry within 24 hours. Feeding was resumed within 48 hours. One patient required laparotomy during the procedure due to injury to the urethra. Two patients required colostomy 3 and 5 days after surgery because of delayed leakage. Three patients suffered from attacks of enterocolitis 6 - 9 months postoperatively. There was increased frequency of defecation (5 - 15 times daily) for 4 - 6 weeks after surgery in all patients. There was no constipation, no incontinence, no cuff abscess and no mortality in any of the patients. Average frequency of defecation was 1 - 3 times daily after 3 months postoperatively. For the open technique group, mean operating time was 150 min, the length of the average resected segment was 29 cm. Forty-one patients had satisfactory results without complications. The cost of the open technique was almost double that of the TEPT (6300 vs. 3200 pounds). CONCLUSIONS: Transanal Endorectal Pull-Through (TEPT) is characterized by a shorter operating time, less bleeding, shorter hospital stay, less morbidity and earlier recovery than similar open pull-through procedures. The hazards and morbidities associated with laparotomy and colostomy may be avoided with a one-stage technique in Hirschsprung's disease confined to the rectosigmoid area (70-80 %). Careful long-term follow-up is required to assess continence and sexual function.

Child↗
PubMed2002

A novel multiplex RT-PCR probe capture hybridization (RT-PCR-ELISA) for simultaneous detection of six viroids in four genera: Apscaviroid, Hostuviroid, Pelamoviroid, and Pospiviroid.

A rapid and sensitive assay was developed for the detection and identification of viroids by standard or multiplex reverse transcription-polymerase chain reaction (RT-PCR)-probe capture hybridization (RT-PCR-ELISA). The assay was applied successfully for the detection and identification of the following six viroid species from infected tissues: Potato spindle tuber viroid (Pospiviroid), Peach latent mosaic viroid (Pelamoviroid), Apple scar skin viroid (Apscaviroid), Apple dimple fruit viroid (Apscaviroid), Pear blister canker viroid (Apscaviroid), and Hop stunt viroid (Hostuviroid). Total RNA was obtained from infected tissue by the Qiagen RNeasy kit and, then viroid cDNA was synthesized using viroid specific complementary DNA primer. To identify and differentiate the amplicons of the six viroids, each amplicon was digoxigenin (DIG)-labelled during the amplification process, and then detected by a colorimetric system using a biotinylated cDNA capture probe specific for each viroid. The results revealed that each capture probe hybridized only to its complementary DIG-labelled amplicon. Thus the six viroids can be detected and differentiated in a multiplex RT-PCR-ELISA assay. In the multiplex assay, cDNAs of six viroids were synthesized simultaneously in one tube, DIG-labelled during amplification, then a portion of the DIG-labelled amplified products was hybridized with selected capture probe. All the six viroid capture probes hybridized to their respective complementary DIG-labelled RT-PCR-amplified product. These findings are important for viroid detection and identification for studying host-viroid interactions and for management and control viroid diseases.

DNA Probes↗
PubMed2001

Bleeding tendency in Wolfram syndrome: a newly identified feature with phenotype genotype correlation.

Wolfram syndrome (WS) is a recessively inherited disorder associated with recognised clinical features. Bleeding tendency was noticed in some of our patients, although this has not been reported before. We therefore studied this problem in all our WS patients and tried to postulate a possible pathogenesis. At the same time, a genetic linkage study provided evidence of locus heterogeneity of this syndrome and showed that the majority of our patients belong to the second WS locus identified in that study. Our study group consisted of 13 WS patients, belonging to WSF2 locus (group I). Controls consisted of 4 healthy siblings of WS patients (group II) and 7 diabetics who do not have WS (group III). Relevant clinical data were obtained, and a coagulation screen was carried out for all groups. All individuals in the three study groups have normal platelet count, thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (aPTT), clot retraction, Factor VIII activity (FVIIIc) and von Willebrand factor antigen (vWAg). Eleven of the WS patients have prolonged template bleeding time (BT) compared with both control groups. Patients with WS have a longer BT (mean 9.6 min, 95% CL 8.61-10.53 min) than the siblings group (mean 6.75 min, 95% CL 5.52-7.98 min) and the diabetic group (mean 5.49 min, 95% CL 4.56-6.42 min). The differences between the study group and controls are statistically significant, p = 0.02 and 0.0002, respectively. In the three groups, platelet aggregation studies were normal using adenosine diphosphate (ADP), ristocetin and epinephrine. Aggregation with collagen was either absent or impaired, with failure of secondary wave being noticed in 11 of the WS patients (85%) and normal in the control groups. The pathogenesis of this problem is not known, but could be due to an inhibitory effect of vWAgII, deficiency of thrombospondin or a defect in the platelet membrane GPIa/IIa. Bleeding diathesis is a new additional feature to the clinical spectrum of WS, which is probably a feature of the disorder WFS2 and not WFS1, as bleeding has never been reported in the latter. This provides further evidence for the phenotypic and genotypic heterogeneity of this complex disorder and may provide clues to the search for the second gene responsible for this phenotype.

Adolescent↗
PubMed2001

Sensitive detection of the Egyptian species of sugarcane streak virus by PCR-probe capture hybridization (PCR-ELISA) and its complete nucleotide sequence.

A rapid and sensitive assay for the specific detection of Sugarcane streak virus (SSV) using PCR-probe capture hybridization (PCR-ELISA) was developed. Nucleic acids suitable for PCR were extracted from SSV-infected tissue using organic solvents or Fast DNA kit. SSV cDNA was amplified using viral specific primers and the amplified SSV cDNA (amplicon) was DIG-labelled during the amplification process. The amplicon was then detected in a colorimetric hybridization system by a microtiter plate using a biotinylated cDNA (22 nt), cDNA (789 nt) or cRNA (789 nt) capture probe. This system combines the specificity of molecular hybridization, the ease of the colorimetric protocol, and is 10-100 fold more sensitive than agarose gel electrophoretic analysis in detecting the amplified product. Long cDNA or cRNA capture probe was 2-7 fold more sensitive than the oligo cDNA probe for the detection. Complete nucleotide sequence of SSV from Naga Hammady, Egypt, revealed that SSV-EG is a new species of SSV that shares 66% nucleotide identity with the virus species from Natal, South Africa.

Cloning, Molecular↗
PubMed2000

Development of a plant-derived subunit vaccine candidate against hepatitis C virus.

Hepatitis C virus (HCV) is a major cause of acute and chronic hepatitis with over 180 million cases worldwide. Vaccine development for HCV has been difficult. Presently, the virus cannot be grown in tissue culture and there is no vaccine or effective therapy against this virus. In this research, we describe the development of an experimental plant-derived subunit vaccine against HCV. A tobamoviral vector was engineered to encode a consensus sequence of hypervariable region 1 (HVR1), a potential neutralizing epitope of HCV, genetically fused to the C-terminal of the B subunit of cholera toxin (CTB). This epitope was selected from among the amino acid sequences of HVR1 "mimotopes" previously derived by phage display technology. The nucleotide sequence encoding this epitope was designed utilizing optimal plant codons. This mimotope is capable of inducing cross-neutralizing antibodies against different variants of the virus. Plants infected with recombinant tobacco mosaic virus (TMV) engineered to express the HVR1/CTB chimeric protein, contained intact TMV particles and produced the HVR1 consensus peptide fused to the functionally active, pentameric B subunit of cholera toxin. Plant-derived HVR1/CTB reacted with HVR1-specific monoclonal antibodies and immune sera from individuals infected with virus from four of the major genotypes of HCV. Intranasal immunization of mice with a crude plant extract containing the recombinant HVR1/CTB protein elicited both anti-CTB serum antibody and anti-HVR1 serum antibody which specifically bound to HCV virus-like particles. Using plant-virus transient expression to produce this unique chimeric antigen will facilitate the development and production of an experimental HCV vaccine. A plant-derived recombinant HCV vaccine can potentially reduce expenses normally associated with production and delivery of conventional vaccines.

Administration, Intranasal↗
PubMed2000

Apricot latent virus: a new species in the genus Foveavirus.

Extraction of viral double-stranded RNA from peach leaves infected with Apricot latent virus (ALV) followed by molecular cloning of synthesized cDNA and its sequencing, suggested that ALV is a new virus, whose coat protein (CP) coding region contains Apple stem pitting virus (ASPV)-related sequences. The sequenced portion of the ALV genome (1,444 nt) includes the putative CP gene and the 3' non-translated region. The 5' portion of this fragment (1-651 nt) is highly distinct whereas the 3' portion is 77% identical to the corresponding region of ASPV. Molecular hybridization experiments using a cRNA probe to ASPV with ALV-infected leaf tissue extracts also revealed that the genome of ALV contains nucleotide sequences related to that of ASPV. Western blots of tissue extracts indicated that ALV coat protein reacted with polyclonal antiserum against ASPV; however, the ALV CP differs in size from that of ASPV. ALV was graft-transmitted to several Prunus rootstocks. Based on the available sequence data, serological observations and bioassays we propose that ALV is a new species in the genus Foveavirus, typified by ASPV. ALV-specific PCR-primers and viral-specific cRNA probes developed in this investigation may be useful for detecting the virus and for studying its epidemiology and geographical distribution.

3' Untranslated Regions↗
PubMed1999

Sensitive detection of potato spindle tuber and temperate fruit tree viroids by reverse transcription-polymerase chain reaction-probe capture hybridization.

A rapid and sensitive assay for the specific detection of plant viroids using reverse transcription-polymerase chain reaction (RT-PCR) -probe capture hybridization (RT-PCR-enzyme-linked immunosorbent assay (ELISA)) was developed. The assay was applied successfully for the detection of potato spindle tuber viroid, peach latent mosaic viroid, or apple scar skin viroid from viroid infected leaf tissue. Clarified sap extract from infected leaf tissue was treated first with GeneReleaser polymeric matrix to remove inhibitors of RT-PCR reactions. Viroid cDNA was then synthesized and amplified using viroid specific primers in RT-PCR assays and the amplified viroid cDNA (amplicon) was digoxigenin (DIG) -labelled during the amplification process. The amplicon was then detected in a colorimetric hybridization system in a microtiter plate using a biotinylated cDNA capture probe. This system combines the specificity of molecular hybridization, the ease of the colorimetric protocol, and is at least 100-fold more sensitive than gel electrophoretic analysis in detecting the amplified product. Viroid cRNA may replace viroid cDNA as the capture probe. The cRNA probe was several fold more sensitive than the cDNA probe for viroid detection. Six to seven hours are needed to complete the RT-PCR-ELISA for viroid detection from infected leaf tissue.

DNA Probes↗
PubMed1998

Nucleotide sequence of the putative replicase gene of the sour cherry strain of plum pox potyvirus.

The complete nucleotide sequence of the NIb coding region of the sour cherry strain of plum pox potyvirus (PPV-SoC) has been determined. It consists of 1554 nucleotides and encodes a putative replicase protein of 518 amino acids. Sequence identity scores between NIb of PPV-SoC and other isolates of PPV are significantly low (c. 78%). Many of the nucleotide substitutions, however, are silent. PPV-SoC differs from isolates of PPV-D, PPV-M and PPV-E1 Amar at multiple amino acid positions that are conserved between the other isolates. The NIb sequence extends the PPV-SoC sequence presently available to 2781 nt from the 3' end (approximately 28% of the genome).

Amino Acid Sequence↗
PubMed1998

Specific oligonucleotide primers for the direct detection of plum pox potyvirus-cherry subgroup.

A specific polymerase chain reaction assay was developed for direct identification of the distinct subgroup of plum pox potyvirus (PPV) isolates from cherry trees (PPV-cherry, PPV-C) and its differentiation from other known subgroups of PPV. The specificity of the assay is based on using a pair of primers whose nucleotide sequences are located on the coat protein gene of PPV-sour cherry (SoC) at regions of high nucleotide divergence between PPV-SoC and other isolates of PPV. The technique will be useful for studying the epidemiology of PPV-C as well as for practical testing in certification and quarantine programs worldwide.

DNA Primers↗
PubMed1994

Sensitive detection of grapevine virus A, B, or leafroll-associated III from viruliferous mealybugs and infected tissue by cDNA amplification.

DNA primers specific for grapevine virus A (GVA), grapevine virus B (GVB) or grapevine leafroll-associated virus III (GLRaV-III) were constructed based on the nucleotide sequence of a segment of each viral genome. DNA primers were utilized for cDNA synthesis and polymerase chain reaction (PCR) amplification of a 430 bp fragment from extracts of GVA-infected grapevine tissue or viruliferous mealybugs and 450 bp and 340 bp DNA fragments from extracts of GVB and GLRaV-III-infected grapevine tissues, respectively. The amplified DNA fragment of each virus was identified by Southern hybridization analysis with a cRNA probe of cloned viral genome. Reverse transcription (RT)-PCR, immunocapture (IC)-RT-PCR and/or multiplex (M)-RT-PCR assays were developed for the detection of GVA, GVB, and/or GLRaV-III in extracts of infected grapevine leaves, dormant cuttings and/or in viruliferous mealybugs. Viral specific DNA was absent from amplified extracts of uninfected grapevine tissue or nonviruliferious mealybugs. IC-RT-PCR was easier to perform than RT-PCR for the detection of GVA from viruliferous mealybugs. M-RT-PCR was easier and faster than IC-RT-PCR for the detection of GLRaV-III from infected grapevine tissue and it allows the sensitive detection of GVB, for which a high titer antiserum is not yet available.

Animals↗
PubMed1994

Simple and rapid preparation of infected plant tissue extracts for PCR amplification of virus, viroid, and MLO nucleic acids.

A rapid, simple method for preparing plant tissues infected with viruses, viroids, or MLOs using a commercial product known as Gene Releaser is described. The Gene Releaser polymeric matrix method produced plant extracts suitable for PCR amplification without the use of organic solvents, ethanol precipitation, or additional nucleic acid purification techniques. Modification of maceration methods and/or extraction buffers resulted in the PCR amplification of potato spindle tuber, apple scar skin, and dapple apple viroids, as well as, genomic segments of plum pox potyvirus, grapevine virus B, grapevine leafroll-associated virus III, and elm yellows MLO. These pathogens were amplified from tissue of woody and herbaceous hosts such as peach, apricot, apple, grapevine, elm, periwinkle and potato. The application of this product for use with intractable tissue avoids lengthy and laborious extraction procedures. In our hands, about 20 samples could be prepared for PCR or RT-PCR in 1-2 h versus 1-3 days.

Base Sequence↗
PubMed1993

Chemiluminescent detection of potato and pome fruit viroids by digoxigenin-labeled dot blot and tissue blot hybridization.

A chemiluminescent molecular hybridization protocol was compared to 32P autoradiography for detecting potato spindle tuber viroid (PSTVd) and apple scar skin group viroids (ASSVd). Labeled cRNA probes for PSTVd and ASSVd were synthesized by SP6 RNA polymerase transcription using digoxigenin-11-UTP or alpha-[32P]UTP. Dot blot hybridization of purified viroids and sap extracts from infected plants showed that chemiluminescent detection using digoxigenin-labeled probes was as sensitive as autoradiography using 32P probes. A minimum of 2.0-2.5 pg purified viroid was detected. ASSVd could be detected in as little as 0.4 ng of total nucleic acid extract from infected tissue or in sap extracts diluted to 10(-3) with healthy extracts. Tissue blots of PSTVd-infected potato tubers and tomato roots, stems and leaves and ASSVd-infected apple fruit, stems and petioles, gave positive reactions when hybridized with the digoxigenin probe. No reaction with similar tissues from healthy plants was observed.

Digoxigenin↗
PubMed1991

cDNA cloning and analysis of RNA 2 of a Prunus stem pitting isolate of tomato ringspot virus.

Recombinant plasmids containing sequences derived from the genome of a tomato ringspot virus (TomRSV) isolate associated with both stem pitting disease of stone fruits and apple union necrosis and decline were constructed. Selected inserts were subcloned into the polylinker region of the SP6 transcription vector pSP64. Using the SP6 promoter flanking this region, high specific activity 32P-labelled cRNA probes were generated by SP6 RNA polymerase. cRNA probes were specific for TomRSV RNA 2 present in purified virions or in extracts from woody and herbacous hosts. No sequence relatedness was detected between TomRSV RNA 2 and genomic RNA from tobacco ringspot, arabis mosaic, strawberry latent ringspot, or cucumber mosaic virus in Northern blot analysis using TomRSV cRNA probes. These probes detected TomRSV infection in woody and herbaceous hosts in dot-blot hybridization assays.

Cloning, Molecular↗
PubMed1990

Detection of pome fruit viroids by enzymatic cDNA amplification.

We have studied the detection of apple scar skin, dapple apple, and pear rusty skin viroids in nucleic acid extracts of infected pome fruit tissues by reverse transcription-polymerase chain reaction (RT-PCR) with viroid cDNA-specific primers. Analysis of RT-PCR-amplified products by gel electrophoresis or by Southern blot hybridization indicated that the new procedure is more sensitive than existing detection methods and provides information about viroid detection without requiring large samples or using molecular hybridization. Our results also suggest the potential utility of the PCR technology in detecting other viroids and possibly other plant pathogens.

Base Sequence↗
PubMed1985

Nucleotide sequence of the satellite of peanut stunt virus reveals structural homologies with viroids and certain nuclear and mitochondrial introns.

Peanut stunt virus-associated RNA 5 (PARNA 5), the satellite of a plant cucumovirus, is a linear RNA of 393 nucleotides with a 5' cap and a 3' hydroxyl group. Determination of its nucleotide sequence has revealed two consecutive open reading frames that together extend most of its length. Sequences at the 5' and 3' ends are homologous with those of the satellite of the related cucumber mosaic virus, and the double-stranded forms of both satellites contain an unpaired guanosine at the 3' end of the minus strand. However, little other homology exists between the two satellites. In contrast, PARNA 5 has several regions of 90% sequence homology with various plant viroids, including sequences of the conserved central region of most viroids. Such homologies suggest a common origin with viroids coupled with specific adaptation as a linear RNA. The presence within PARNA 5 of conserved intron sequences essential to proper RNA processing suggests a possible origin from plant introns and/or involvement of such sequences in the processing of PARNA 5 multimers to monomers at some stage of replication.

Base Sequence↗