Exploring the association of succinate dehydrogenase complex mutations with lymphoid malignancies.

The succinate dehydrogenase (SDH) complex exerts a fundamental role in mitochondrial cellular respiration and mutations in its encoding genes (SDHA, SDHB, SDHC, SDHD, collectively referred to as SDHx) lead to a number of inherited endocrine cancer predisposition syndromes, including familial paraganglioma/pheochromocytoma. Recent studies suggest a possible role for the SDH complex and other mitochondrial enzymes in the pathogenesis of hematological malignancy. Our aim was to search and identify pedigrees of patients affected by germline SHDx mutations treated at our institution for endocrine and other tumors, and seek to identify cases of hematological malignancy. We also analyzed cancer genome databases for reported cases of SDHx mutations outside of endocrine neoplasms. We report of two unrelated pedigrees carrying SDHx mutations with members affected by lymphomas. Sequencing data revealed one case of chronic lymphocytic leukemia with a SDHB mutation. This novel set of observations demonstrates the need for collaborative databases of patients with endocrine cancers with SDHx mutations, and the investigation of their role in hematological (lymphoid) malignancy.

SYK regulates mTOR signaling in AML.

Spleen tyrosine kinase (SYK) was recently identified as a new target in acute myeloid leukemia (AML); however, its mechanistic role in this disease is poorly understood. Based on the known interaction between SYK and mammalian target of rapamycin (mTOR) signaling in lymphoma, we hypothesized that SYK may regulate mTOR signaling in AML. Both small-molecule inhibition of SYK and SYK-directed shRNA suppressed mTOR and its downstream signaling effectors, as well as its upstream activator, AKT. Moreover, the inhibition of multiple nodes of the phosphatidylinositol 3'-kinase (PI3K) signaling pathway enhanced the effects of SYK suppression on AML cell viability and differentiation. Evaluation of the collateral mitogen-activated protein kinase (MAPK) pathway revealed a heterogeneous response to SYK inhibition in AML with downregulation of MEK and extracellular signal-regulated kinase (ERK) phosphorylation in some AML cell lines but a paradoxical increase in MEK/ERK phosphorylation in RAS-mutated AML. These studies reveal SYK as a regulator of mTOR and MAPK signaling in AML and demonstrate that inhibition of PI3K pathway activity enhances the effects of SYK inhibition on AML cell viability and differentiation.

The exstrophy-epispadias complex: is aesthetic appearance important?

OBJECTIVE: To show the relevance of cosmetic appearance in the adequate treatment of patients with exstrophy-epispadias complex (EEC), and to indicate that surgery by experienced teams can improve the long-term treatment forecast and the patient's body image. PATIENTS AND METHODS: From 1978 to 2002, 71 patients diagnosed with EEC were treated in the authors' institution; 24 (aged 2-23 years) were selected to undergo different surgical procedures. The criterion for surgery considered interviews conducted by the psychology team with the parents and children. The plastic surgery and paediatric urology teams carried out the procedures jointly; the follow-up was 0.33-7 years. RESULTS: Five female patients and six male had abdominoplasty to treat multiple scars; eight had intermittent catheterization conduits repositioned from the right iliac fossa to the umbilicus. Six female patients had plastic surgery of the external genitalia and three had a broad mobilization of the urogenital sinus. Thirteen male patients had a small penis and had the corpora cavernosa fully mobilized and the penis reconstructed. Five female patients and one male had anterior osteotomy. One patient with no left testis had it replaced and one patient with uterine prolapse had the uterus fixed to the posterior abdominal wall. Six patients had a second procedure, in two because the outcome of the initial operation was poor and in the others to complement the initial treatment. In all but one patient there was an improvement in the objective criteria, e.g. school absences, difficulty in establishing long-lasting social relationships and refusal to participate in sports activities. However, none of the patients would attempt sexual intercourse. CONCLUSIONS: Body image, self-esteem, sexuality, sexual function and fertility are deemed crucial by adolescents; in patients with EEC customised surgical procedures can give a satisfactory aesthetic outcome, and be a further reason for adequately following occasional urinary complications and renal function, to avoid loss to follow-up.

Posterior urethral injuries and the Mitrofanoff principle in children.

OBJECTIVE: To report our experience of children with trauma causing posterior urethral injury who at some stage underwent a Mitrofanoff intervention, as post-traumatic urethral injuries can demand long-term treatment which (regardless of the surgical intervention) requires a period of dilatation of the reconstructed urethra. PATIENTS AND METHODS: From 1992 to 2001, 14 patients with urethral injuries underwent a Mitrofanoff procedure. Thirteen had been run over by a motor vehicle and had severe hip injuries, and one had a direct non-penetrating perineal impact lesion (13 boys and one girl, aged 2-13 years at the time of the accident). In all cases the Mitrofanoff procedure involved interposing the appendix between the bladder and the umbilicus. Only one of the children (because of extremely high bladder filling pressures) also underwent an augmentation cystoplasty and closure of the bladder neck because there were bony fragments in the urethra. RESULTS: The Mitrofanoff technique was considered useful in most cases. All patients during a given period used the Mitrofanoff conduit to empty their bladder every 3 h; 10 of the 14 are currently voiding urethrally, with an adequate flow, and four are not, but emptying the bladder periodically via the appendicovesicostomy. The only girl in the group has a major hip deformity and is unlikely to undergo urethroplasty; two patients are expecting definitive treatment and the other, although having a patent urethra, has no urinary flow. He is currently 19 years old and has no erections. CONCLUSIONS: The treatment of posterior urethral injuries represents a challenge to surgical teams. Although primary suturing of the separated urethral ends is accepted as the best treatment, the construction of a temporary continent urinary diversion may be considered in the most severe cases.

A posterior-based omega-shaped flap vaginoplasty in girls with congenital adrenal hyperplasia caused by 21-hydroxylase deficiency.

OBJECTIVE: To describe a technical modification for constructing a vagina in girls with congenital adrenal hyperplasia caused by 21-hydroxylase deficiency, using a narrower skin base but rich subcutaneous tissue, aiming to obtain both longer and larger vaginal segments with better cosmesis of the external genitalia. PATIENTS AND METHODS: From August 1997 to February 2001, 28 girls (aged 5 months to 17 years) had a neovagina constructed using a posterior-based omega-shaped flap. Twenty-six patients had a low vagina entering into the urogenital sinus and two had a high vagina that entered the urogenital sinus. In those with a high vagina the flap procedure was combined with the Passerini-Glazel technique. All the patients were scheduled for vaginal "calibrations" during the first year after surgery and, according to the result, would then undergo vaginal dilatation. RESULTS: Six children were re-operated; five had plastic surgery to correct genital folds that had regained a scrotal aspect, whereas one with a high vagina developed a urethral stricture, with urinary dribbling and infection, and had the urethra reconstructed. These six children are currently well. No hormone therapy was given to one child for 1 year who is scheduled for further surgery for a re-virilized clitoris. Two patients were lost to follow-up. Up to the last visit, 19 girls had not developed a vaginal stricture and the cosmesis of their external genitalia was deemed good. CONCLUSION: The posterior-based omega-shaped flap enabled both the construction of wider vaginal segments with a low risk of developing stenosis in those with a low vagina, and increased vaginal dimension when associated with the Passerini-Glazel technique for those with a high vagina. However, despite good cosmesis of the external genitalia, the follow-up is too short to confirm whether this technique will meet all the expectations.

Sigmoid reconfigured vaginal construction in children.

PURPOSE: We present a modified technique of sigmoid neovaginal construction in children that protects the sigmoid pedicle from traction, allows easy adjustment of caliber and reorients the mucosal fold in a longitudinal direction. MATERIALS AND METHODS: From 1997 to 2000, 10 genetically male (46 XY) children 1 to 13 years old underwent construction of a neovagina with sigmoid, incorporating the Yang-Monti concept of intestinal reconfiguration. The diagnosis was androgen insensitivity in 7 patients, congenital adrenal hyperplasia in 2 due to 17 alpha-hydroxylase deficiency and 3 beta-hydroxysteroid dehydrogenase deficiency, respectively, and bladder exstrophy in 1 who required sex reassignment. RESULTS: Eight children had an adequate caliber neovagina after an initial period of systematic dilation. In 1 case a relevant stricture required reoperation using the same technique and the outcome was good. In another child a stricture developed in the middle of the reconfigured sigmoid segment and a regular dilation schedule is still being followed after 23 months of followup. CONCLUSIONS: The new sigmoid reconfiguration technique enables the use of smaller dimension intestinal segments and construction of a long vaginal conduit of adequate caliber. Its optimal adequacy for penetration must be assessed in the future after these patients begin sexual activity.

Gastrocystoplasty and chronic renal failure: an acid-base metabolism study.

PURPOSE: To verify in an experimental model whether gastrocystoplasty may protect patients with chronic renal failure from acid loading associated acidosis a wedge-shaped portion of the middle stomach was used to improve bladder capacity in animals with chronic renal failure. MATERIALS AND METHODS: An experimental model was used to study 112 adult female Wistar rats (EPM-1) weighing between 156 and 259 gm. The animals were randomly assigned to groups, including 41 controls, 24 undergoing five-sixths nephrectomy to create chronic renal failure, 26 undergoing gastrocystoplasty and 21 undergoing gastrocystoplasty and five-sixths nephrectomy to create renal failure. To provide an acid overload a 5% NH(4)Cl diet was administered to a subgroup of each group. Two months after surgery 24-hour urine was collected, and volume and pH were measured as well as the amount of bicarbonate, ammonium, titratable acidity and chloride. The animals were then exsanguinated through an abdominal aorta puncture. The blood was used for blood gas analysis and to measure sodium, potassium, chloride, ionized calcium and creatinine. RESULTS: When undergoing an acid overload, the animals with gastrocystoplasty had no acidosis since acid radicals were eliminating in the urine as NH(4)Cl. When given the same acid overload, metabolic acidosis developed in the animals with gastrocystoplasty and chronic renal failure. CONCLUSIONS: Gastrocystoplasty protected healthy rats from acidosis when they were given an acid overload but failed to protect the rats with chronic renal failure under the same conditions.

Humoral, hormonal and behavioral correlates of feeding in ponies: the effects of meal frequency.

The effect of meal frequency on body fluid, glucose, triiodothyronine (T3), heart rate and behavior was measured in 10 ponies. A simple reversal design was used in which each pony received one meal/day (1X) for 2 wk and six meals/day (6X) for 2 wk. The total intake/day was held constant. Feeding was followed by a rise in plasma levels of glucose, T3, protein and osmolality. One large meal was followed by significantly greater changes in all of the variables than was a meal one-sixth the size. Plasma T3 rose from 41 +/- 5 (SE) ng/liter before feeding to 43 +/- 5 ng/liter following a small meal, but rose significantly higher, from 39 +/- 4 to 60 +/- 10 ng/liter, following a large meal. Glucose rose from 84 +/- 3 to 109 +/- 7 mg/dl following a small meal and rose significantly higher, from 83 +/- 3 to 154 +/- 11 mg/dl, after a large meal. Plasma protein rose from 6.55 +/- .14 to 6.62 +/- .16 g/dl following a small meal and from 6.45 +/- .14 to 6.99 +/- .11 g/dl following a large meal. Osmolality rose from 227 +/- 1 mosmol/liter before to 279 +/- 1 mosmol/liter following a small meal and significantly higher from 278 +/- 2 to 285 +/- 1 mosnol/liter following a large meal. Heart rate rose from 42 beats/min in the absence of feed to 50 beats/min when food was visible to the ponies and did not rise higher when eating began. There were no significant differences in the cardiac response to one large meal and that to a small meal.(ABSTRACT TRUNCATED AT 250 WORDS)

Feeding and drinking behavior of mares and foals with free access to pasture and water.

The feeding and drinking behavior of 11 mares and 15 foals living on pasture with free access to water was recorded during 2,340 15-min focal samples taken over 2 yr. Lactating mares on pasture spent about 70% of the day feeding. Foals began feeding on their first day of life. As they grew older, they spent progressively more time feeding, but still spent only 47 +/- 6% of the time feeding by 21 wk of age. Foals fed primarily during the early morning and evening. While grass formed the major proportion of the diet of both foals and mares, they also ate clay, humus, feces, bark, leaves and twigs. Almost all feeding by foals was done while their mothers were feeding. Movement to water sources was frequently, but not invariably, carried out by an entire herd. Frequency (P = .005) but not duration (P greater than .05) of drinking bouts by mares increased as the temperature increased. Frequency was greatest at 30 to 35 C, at which temperature mares drank once every 1.8 h. Frequency of drinking varied with the time of day (P less than .01), being rarest during the early morning (0500 to 0900 h eastern daylight time) and most frequent during the afternoon (1300 to 1700 h). Drinking by foals was very rare. The youngest age at which a foal was observed to drink was 3 wk, and 8 of 15 foals were never observed to drink before weaning.

Testicular regression in a patient with virilized female phenotype.

The 16-year old girl studied here had ambiguous external genitalia, ie, enlarged clitoris, pseudo vagina, and rudiments of Wolffian tubes. Her karyotype was 46,XY and she was H-Y antigen-positive. In spite of absence of gonadal tissue, genital virilization suggests presence of testes during embryogenesis. This patient is compared to 20 others with testicular regression from the literature. Autosomal-recessive inheritance of this condition is proposed.