Renal malformations associated with mutations of developmental genes: messages from the clinic

Renal tract malformations (RTMs) account for about 40% of children with end-stage renal failure. RTMs can be caused by mutations of genes normally active in the developing kidney and lower renal tract. Moreover, some RTMs occur in the context of multi-organ malformation syndromes. For these reasons, and because genetic testing is becoming more widely available, pediatric nephrologists should work closely with clinical geneticists to make genetic diagnoses in children with RTMs, followed by appropriate family counseling. Here we highlight families with renal cysts and diabetes, renal coloboma and Fraser syndromes, and a child with microdeletion of chromosome 19q who had a rare combination of malformations. Such diagnoses provide families with often long-sought answers to the question “why was our child born with kidney disease”. Precise genetic diagnoses will also help to define cohorts of children with RTMs for long-term clinical outcome studies.     

Open reduction and internal fixation in a case with transscaphoid perilunate dislocation 8 months after the injury: a patient with a 5-year follow-up

The management of perilunate dislocations diagnosed later than three months continue to elicit debate with literature being scarce. We report a 22-year-old male with transscaphoid perilunate dislocation who reported to our hospital 8 months after sustaining the injury. Open reduction was done along with bone grafting. Five years after the surgery the patient is symptom-free with an excellent range of motion.     

An antibiotic produced by an insect-pathogenic bacterium suppresses host defenses through phenoloxidase inhibition

Photorhabdus is a virulent pathogen that kills its insect host by overcoming immune responses. The bacterium also secretes a range of antibiotics to suppress the growth of other invading microorganisms. Here we show that Photorhabdus produces a small-molecule antibiotic (E)-1,3-dihydroxy-2-(isopropyl)-5-(2-phenylethenyl)benzene (ST) that also acts as an inhibitor of phenoloxidase (PO) in the insect host Manduca sexta. The Photorhabdus gene stlA encodes an enzyme that produces cinnamic acid, a key precursor for production of ST, and a mutation in stlA results in loss of ST production and PO inhibitory activity, which are both restored by genetic complementation of the mutant and also by supplying cinnamic acid. ST is produced both in vitro and in vivo in sufficient quantities to account for PO inhibition and is the only detectable solvent-extractable inhibitor. A Photorhabdus stlA- mutant is significantly less virulent, proliferates slower within the host, and provokes the formation of significantly more melanotic nodules than wild-type bacteria. Virulence of the stlA- mutant is also rescued by supplying cinnamic acid. The proximate cause of the virulence effect, however, is the inhibition of PO, because the effect of the stlA- mutation on virulence is abolished in insects in which PO has been knocked down by RNA interference (RNAi). Thus, ST has a dual function both as a PO inhibitor to counter host immune reactions and also as an antibiotic to exclude microbial competitors from the insect cadaver.     

Allene formation by gold catalyzed cross-coupling of masked carbenes and vinylidenes

Addition of a sterically demanding cyclic (alkyl)(amino)carbene (CAAC) to AuCl(SMe(2)) followed by treatment with [Et(3)Si(Tol)](+)[B(C(6)F(5))(4)](-) in toluene affords the isolable [(CAAC)Au(eta(2)-toluene)](+)[B(C(6)F(5))(4)](-) complex. This cationic Au(I) complex efficiently mediates the catalytic coupling of enamines and terminal alkynes to yield allenes and not propargyl amines as observed with other catalysts. Mono-, di-, and tri-substituted enamines can be used, as well as aryl-, alkyl-, and trimethylsilyl-substituted terminal alkynes. The reaction tolerates sterically hindered substrates and is diastereoselective. This general catalytic protocol directly couples two unsaturated carbon centers to form the three-carbon allenic core. The reaction most probably proceeds through an unprecedented "carbene/vinylidene cross-coupling."     

Labor management in a patient with von Willebrand disease

von Willebrand disease (VWD) is an inherited bleeding disorder involving a deficiency or abnormal function of a blood clotting protein called von Willebrand factor (VWF). Deficiency of VWF, therefore, shows primarily in organs with small blood vessels such as the skin, the gastrointestinal tract and the uterus. This case report describes management of a patient presenting with type II von Willebrand disease in labor. She had history of life-threatening hemorrhage from an operation for deviated nasal septum and had a risk of severe postpartum hemorrhage (PPH) within 48 hors of delivery, which was avoided by appropriate planning and timely management.     

Late onset neurogenic claudication in a case of metallic intradural ballistic fragment

Metallic foreign bodies in the intradural location are rare. Even rarer is the absence of neurodeficit in such cases. We report a case where the patient came to the outdoor department of our hospital with symptoms of neurogenic claudication. From history the patient did not volunteer the information which was pertinent to his symptomatology. On examination he was asked about the small scar in his lumbar region. He attributed it to the subjectively insignificant trauma he had sustained when he had been trapped in a crossfire and had been hit by a fragment. The patient had been absolutely symptom free for 12 months after the event followed by 6 months of increasing claudication. X-ray and CT examination revealed the presence of a metallic foreign body in the lumbar spinal canal. Surgical exploration and removal correlated the presence. This case report substantiates the view that a patient with a foreign body in the spinal canal is always a potential candidate for surgery.     

A census-based analysis of racial disparities in lower extremity amputation rates in Northern Illinois, 1987-2004

BACKGROUND: Given improvements in care for peripheral vascular disease and diabetes over the last two decades, it was of interest whether racial disparities in lower extremity amputation rates had changed. METHODS: Hospital data for 18 years (1987-2004) were used to compute above, below, and through foot amputation rates for over eight million people living in the Chicago metropolitan area. Three areas were created from zip code level census data. Differences in amputation rates were compared between residents of zip code areas that were >50% African American, 10% to 50% African American, or <10% African American. RESULTS: The largely African American area of the South and West sides of Chicago, with less than 15% of the area population, accounted for 27% of all amputation discharges (n = 33,775) over the 18 years. For all residents of northern Illinois, major (above and below knee) amputation rates declined to 17 per 100,000 residents over the last decade, and both inpatient mortality and length of stay fell throughout the period. However, residents of largely African American zip codes had over five times higher per capita amputation rates than residents of primarily white zip codes. CONCLUSIONS: Racial disparities have remained remarkably constant, despite progress in reducing the overall major amputation rate in northern Illinois. Addressing these disparities will require that low income, medically complex patients at risk of limb loss receive timelier, high performance care, combined with community-based public health and preventive medicine interventions that address the social determinants of health.     

In situ instrumented posterolateral fusion without decompression in symptomatic low-grade isthmic spondylolisthesis in adults

Forty patients with an average age of 26.5 years were treated for symptomatic low-grade isthmic spondylolisthesis with in situ instrumented posterolateral fusion. All patients had failed previous conservative treatment. Average follow-up was 42.2 months (range: 30-62 months). Low-back pain resolved in 70% of the patients, whereas 65% of those with radicular pain reported complete resolution of the symptoms. At the final follow-up 82.5% of the patients had improvement in their function. Solid fusion was achieved in 70% of the patients. It was uncertain in 10% and a fusion failure was seen in 20%. The anterior slippage as measured by the Taillard method was 31.55% and an average 35% correction was seen after surgery. However, an average 10% loss of correction was seen at the final evaluation. The clinical results were evaluated by Kim and Kim criteria. Satisfactory results were obtained in 65% of patients and this was closely associated with the rate of successful fusion. The results suggest that clinical outcome is closely related to the attainment of solid fusion and decompression or removal of the loose laminar fragment seems unnecessary in patients without major neurological symptoms.