Characterizing Repeats in Two Whole-Genome Amplification Methods in the Reniform Nematode Genome.

One of the major problems in the U.S. and global cotton production is the damage caused by the reniform nematode, Rotylenchulus reniformis. Amplification of DNA from single nematodes for further molecular analysis can be challenging sometimes. In this research, two whole-genome amplification (WGA) methods were evaluated for their efficiencies in DNA amplification from a single reniform nematode. The WGA was carried out using both REPLI-g Mini and Midi kits, and the GenomePlex single cell whole-genome amplification kit. Sequence analysis produced 4 Mb and 12 Mb of genomic sequences for the reniform nematode using REPLI-g and SIGMA libraries. These sequences were assembled into 28,784 and 24,508 contigs, respectively, for REPLI-g and SIGMA libraries. The highest repeats in both libraries were of low complexity, and the lowest for the REPLI-g library were for satellites and for the SIGMA library, RTE/BOV-B. The same kind of repeats were observed for both libraries; however, the SIGMA library had four other repeat elements (Penelope (long interspersed nucleotide element (LINE)), RTE/BOV-B (LINE), PiggyBac, and Mirage/P-element/Transib), which were not seen in the REPLI-g library. DNA transposons were also found in both libraries. Both reniform nematode 18S rRNA variants (RN_VAR1 and RN_VAR2) could easily be identified in both libraries. This research has therefore demonstrated the ability of using both WGA methods, in amplification of gDNA isolated from single reniform nematodes.

Electrostatically Tunable Adhesion in a High Speed Sliding Interface.

Contact hysteresis between sliding interfaces is a widely observed phenomenon from macro- to nanoscale sliding interfaces. Most such studies are done using an atomic force microscope (AFM) where the sliding speed is a few µm/s. Here, we present a unique study on stiction between the head-disk interface of commercially available hard disk drives, wherein the vertical clearance between the head and the disk is of the same order as in various AFM-based fundamental studies but with a sliding speed that is nearly 6 orders of magnitude higher. We demonstrate that, although the electrostatic force (dc or ac voltage) is an attractive force, the ac-voltage-induced out-of-plane oscillation of the head with respect to the disk is able to completely suppress the contact hysteresis.

Robotic treatment of a type 2 calyceal diverticulum in a child: is suture closure and marsupialisation enough for a good outcome?

Calyceal diverticula in children are rare and 20% eventually become symptomatic. Following the use of laparoscopic or endoscopic treatments, 85% of children report symptomatic relief. However, complete radiological resolution is seen only in three-fourths of the laparoscopic group and a quarter of those treated via endoscopy. Diathermy ablation of the lining and/or prolonged double J stenting has not altered this outcome. The robotic approach is superior to the other two techniques as the leak can be clearly identified and securely suture ligated. We believe that this is the third published report of the successful closure of a calyceal diverticulum in a child using robotic assistance. A ten-year-old boy presented with severe pain in the right flank and a palpable renal swelling. Retrograde injection of contrast outlined a large exophytic calyceal diverticulum (type 2) in the lower pole. Robotic assistance allowed precise suture closure of the neck as well as partial marsupialisation of the diverticulum. The child was discharged within 48 h and remains symptom free 18 months later. Calyceal diverticula are rare but technically challenging entities. We have shown a good outcome with only suture closure of the leak. Diathermy ablation of the lining and prolonged internal stenting were avoided.

Salvage hypospadias repairs.

AIM: Review of our experience and to develop an algorithm for salvage procedures in the management of hypospadias cripples and treatment of urethral strictures following hypospadias repair. METHODS: This is a retrospective review of hypospadias surgeries over a 41-month period. Out of a total 168 surgeries, 20 were salvage/re-operative repairs. In three children a Duplay repair was feasible, while in four others a variety of single-stage repairs could be done. The repair was staged in seven children - buccal mucosal grafts (BMGs) in five, buccal mucosal tube in one, and skin graft in one. Five children with dense strictures were managed by dorsal BMG inlay grafting in one, vascularized tunical onlay grafting on the ventrum in one, and a free tunical patch in one. Three children were treated by internal urethrotomy and stenting for four weeks with a poor outcome. RESULTS: The age of children ranged from 1.5-15 years (mean 4.5). Follow-up ranged from 3 months to 3.5 years. Excellent results were obtained in 10 children (50%) with a well-surfaced erect penis and a slit-like meatus. Glans closure could not be achieved and meatus was coronal in three. Two children developed fistulae following a Duplay repair and following a staged BMG. Three repairs failed completely - a composite repair broke down, a BMG tube stenosed with a proximal leak, and a stricture recurred with loss of a ventral free tunical graft. CONCLUSIONS: In salvage procedures performed on hypospadias cripples, a staged repair with buccal mucosa as an inlay in the first stage followed by tubularization 4-6 months later provides good results. A simple algorithm to plan corrective surgery in failed hypospadias cases and obtain satisfactory results is devised.

MURCS association.

The MURCS association i.e. MUllerian duct aplasia, Renal aplasia, Cervicothoracic Somite dysplasia is a rare developmental disorder. The authors report a case of MURCS association with supernumerary ribs in a 7-month-old infant who presented with failure to thrive.

Multicystic dysplasia in one-half of a horseshoe kidney with megaureter and lower ureteric atresia.

During evaluation of chronic abdominal pain, a 9-year-old male was found to have a horseshoe kidney (HSK) with multicystic dysplasia (MCD) of the left-sided component. Attached to the MCD was a very large, tortuous ureter occupying almost the whole left side of the abdomen. This ureter on dissection was found to end blindly adjacent to the bladder. MCD of one-half of a HSK is an unusual lesion. Its association with a large megaureter with juxtavesical atresia is a unique event. In HSKs, controversy exists about the need to remove a small dysplastic segment. If this segment is associated with a large ureter, as in our case, removal is mandatory in order to avoid pain and infection.

Wilms' tumor with vena caval, atrial, and middle hepatic vein tumor thrombus.

A 3-year-old male with a right-sided Wilms' tumor presented with tender hepatomegaly and bilateral lower-limb edema. Ultrasound and echocardiography showed a massive tumor thrombus completely occluding the inferior vena cava, right atrial cavity, and extending retrogradely into the middle hepatic vein. Two courses of preoperative chemotherapy (vincristine, actinomycin D, adriamycin) caused minimal shrinkage of the thrombus. The tumor and thrombus were successfully removed with the patient under cardiopulmonary bypass and deep hypothermic circulatory arrest followed by multiagent chemotherapy (vincristine, actinomycin D, adriamycin, cyclophosphamide). The child is alive and well with no evidence of disease 15 months later. Occlusion of the hepatic vein by a tumor thrombus in Wilms' tumor is a very rare event. It was completely removed by the right atrial route under direct vision in this child.

Pelviureteric obstruction in children: conventional pyeloplasty is superior to endo-urology.

BACKGROUND: Hydronephrosis secondary to pelviureteric junction (PUJ) obstruction is common in infancy and childhood. Pyeloplasty has until recently been the accepted method of management, but alternative endo-urological techniques have evolved in the last decade. METHODS: Published results of conventional pyeloplasty for primary PUJ obstruction in children were compared with published results of endo-urological procedures. RESULTS: Sixty-six pyeloplasties were performed in 61 children in a 6-year period. During a similar period, 63 primary endo-urological procedures were reported in the literature. The success rate after pyeloplasty was 95.5% compared with 65% after endo-urology. CONCLUSIONS: Conventional pyeloplasty is superior to endo-urology and should remain the gold standard for the treatment of primary PUJ obstruction in children.

Gender reversal in 46XX congenital virilizing adrenal hyperplasia.

OBJECTIVE: To review the results of gender reversal in six patients with 46XX congenital virilizing adrenal hyperplasia (CVAH). PATIENTS AND METHODS: Fifty-one patients with 46XX CVAH were seen in an 8 year period; 45 were managed by conventional feminizing genitoplasty, but six underwent gender reversal and were managed as males. The clinical decision for gender reversal was made after appropriate counselling and was based primarily on parental choice, this being influenced significantly by a delayed diagnosis in four patients. Surgical management consisted of gonadectomy, excision of Müllerian structures and staged hypospadias repair/ chordee correction in four patients, and circumcision in two completely masculinized children. RESULTS: All six boys are well adjusted to their gender of rearing, with ages ranging from 3 years to 16.5 years (mean 8.5) at the time of review. Two children have normal penises and four have a satisfactory result after two-stage repair of hypospadias/chordee. CONCLUSION: Most patients with 46XX CVAH are preferably raised as females and require a feminizing genitoplasty. However, the clinical decision may be influenced by many factors, including delay in diagnosis, social bias and the premium on male rearing in certain communities. When male rearing is chosen, early gonadectomy and excision of Müllerian structures, together with staged hypospadias repair, gives satisfactory results.

Urogenital sinus with sinorectal H-fistula - a hitherto undescribed anorectal anomaly.

In a urogenital sinus anomaly, the urethra and vagina are conjoint for a variable distance and the anorectum is usually intact and complete. We report a case of a urogenital sinus with a fistula between the rectum and the sinus. The anomaly was successfully repaired at 2.5 years of age through a midline muscle-splitting incision in the anterior perineum. The anterior wall of the anorectum was divided in the line of the incision in order to deal with the fistula. Repair was done in layers.

Familial occurrence of complete agenesis of the diaphragm.

The tenth occurrence of complete unilateral agenesis of the diaphragm (McKusick 22240) in siblings is reported in this study. It is likely that parents of children with this type of congenital diaphragmatic hernia have a significantly increased recurrence risk for future offspring. Genetic counselling and antenatal ultrasound should be considered for subsequent pregnancies in families with a previous child with complete agenesis of the diaphragm.

Mid-ileal stricture and spinal injury sustained by a 7 year old child restrained by a lap seat belt involved in a motor vehicle accident.

Lap belts are a feature of the middle seat occupant in the rear seat of most Australian family cars. Without the provision of a child harness, they are inadequate to restrain children under eight years of age. We report a motor vehicle accident involving a seven year old child wearing an adult lap belt which resulted in an ileal stricture and a potentially unstable distraction injury of the lumbar spine.

Primary obstructive megaureter.

Twenty-three children with primary obstructive megaureters presented between 1978 and 1988 to the Princess Margaret Hospital for Children in Perth. Twenty-eight ureters were treated. Urinary infections were the presenting feature in 14 children. The obstructive segment was transvesically excised. Histopathologic examination of the distal, intramural ureter showed fibromuscular disarray with a relative increase in fibrous tissue and reduction of musculature in all specimens. Twenty-two ureters were tapered by excision and all 28 were reimplanted using an antireflux technique. Seventeen children were followed for an average of 3 years. Seven children showed renal growth, reduction in ureteric size by greater than 2 cm, improvement in glomerular filtration rate by more than 10%, no obstruction on reflux, and no infections in postoperative period. Four children showed all the above but suffered one or more infections after the operation. Of the remaining 6 children, 3 had postoperative obstruction and 3 had vesicoureteric reflux.