Tyrosinemia type 1 in pediatric nephrology: Not always straightforward

The main clinical features of tyrosinemia type 1 usually appear in the first months of life, including fever, diarrhea, vomiting, liver involvement, growth failure, and renal proximal tubulopathy with subsequent hypophosphatemic rickets. An early diagnosis is crucial in order to provide specific management and to prevent complications. Here, we report on two cases referred primarily to pediatric nephrologists for the diagnosis of “neonatal tubulopathy” and management of “X-linked hypophosphatemia (XLH),” respectively. Our aim is to emphasize that (1) even a mixed tubulopathy can reveal tyrosinemia, and (2) tyrosinemia is a classic differential diagnosis of XLH that should not be forgotten, especially in the era of the anti-FGF23 burosumab.     

Horizontal advancement flap for lateral dorsal nasal defects

BACKGROUND: Repairing dorsal nasal defects is a frequent challenge for dermatologic surgeons, mainly due to the high frequency of basal cell carcinomas on this site. Obvious scars, mismatched skin and distortion of the nasal contour are the surgical hazards that must be avoided in these cases. AIM: Our aim was to perform surgery involving a simple flap in order to repair medium to large defects on the dorsal side of the nose. METHODS: The dorsal horizontal advancement flap was studied in 12 patients, in order to evaluate the benefits and limits of this surgical procedure. RESULTS: The resulting scars on most of our patients were well-camouflaged among their natural skin lines, and there was neither distortion of the alar contour nor the nostril. CONCLUSIONS: This flap is easy to perform and, in selected cases, provides an outstanding alternative to second-intention healing, full-thickness skin grafts, transposition, rotation and pedicle flaps.     

Role of retinol in protecting epithelial cell damage induced by Clostridium difficile toxin A

Vitamin A (retinol), a fat-soluble vitamin, is an essential nutrient for the normal functioning of the visual system, epithelial cell integrity and growth, immunity, and reproduction. Our group has investigated the effect of high doses of oral vitamin A on early childhood diarrhea in our prospective community-based studies from Northeast Brazil and found a beneficial role in reducing the mean duration but not incidence of diarrheal episodes. In this study, we explored the role of retinol supplementation in intestinal cell lines following Clostridium difficile toxin A (TxA) challenge. C. difficile is the most common anaerobic pathogen borne with antibiotic-borne diarrhea and pseudomembranous colitis. Since retinol is critical for the integrity of tight junctions and to modulate the cell cycle, we have focused on changes in transepithelial electrical resistance (TEER) in Caco-2, a more differentiated intestinal cell line, and on models of cell proliferation, migration and viability in IEC-6 cells, an undifferentiated crypt cell line, following TxA injury. In this model, retinol therapy reduced apoptosis, improved cell migration and proliferation, and prevented the reduction in TEER, following C. difficile TxA challenge in a glutamine-free medium. These results suggest the role of retinol in protecting intestinal epithelial barrier function from C. difficile TxA enterotoxic damage.     

Labially displaced ectopically erupting maxillary permanent canine: interceptive treatment and long-term results.

This case report demonstrates how extracting a maxillary deciduous canine affects the eruption path of a labially displaced ectopically erupting permanent canine. A long-term follow-up is presented, and the biologic mechanisms are discussed.     

Bacterial lipase and high-fat diets in canine exocrine pancreatic insufficiency: A new therapy of steatorrhea?

BACKGROUND & AIMS: Nutrients and properties of lipases affect survival of lipolytic activity during aboral gastrointestinal transit. Whether different doses and formulations of bacterial lipase and diets affect steatorrhea was tested in pancreatic-insufficient dogs. METHODS: A dose of 0-600,000 IU of powdered and 135,000 and 300,000 IU of liquid bacterial lipase was given with a standard meal to 5 dogs with ligated pancreatic ducts. In 4 dogs, 0 or 300,000 IU (normal 6-hour postprandial amount) of powder bacterial lipase was also given with five meals containing 850 kcal with different nutrient caloric densities (mixture design). Coefficients of fat absorption during 72- hour fecal balance studies were used to assess treatments. RESULTS: With the standard meal, powder bacterial lipase reduced steatorrhea in a dose-dependent manner (P = 0.03), and 135,000 and 300,000 IU of the liquid form decreased steatorrhea more than powder bacterial lipase (P = 0.017 and 0.057, respectively). Coefficients of fat absorption with 300,000 IU of powder bacterial lipase correlated (r2 = 0.79; P < 0.001) with increasing proportions of fat calories in diets. CONCLUSIONS: Liquid bacterial lipase decreases steatorrhea more than powder, and 300,000 IU of powder bacterial lipase ingested with high-fat meals corrects canine pancreatic steatorrhea. The combination of adequate mixing of small amounts (milligrams) of bacterial lipase and high-fat meals abolishes canine steatorrhea and may abolish human pancreatic steatorrhea. (Gastroenterology 1997 Jun;112(6):2048-55)     

S-nitrosoglutathione-containing hydrogel accelerates rat cutaneous wound repair

BACKGROUND: Nitric oxide (NO) plays a key role in wound repair and S-nitrosothiols like S-nitrosoglutathione (GSNO) are well known NO donors. METHODS: Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 microm)-containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re-epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin-fixed, paraffin embedded for histological analysis. RESULTS: Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P<0.05 for both). The re-epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P<0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty-one days after wounding, thin red-yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO-treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups. CONCLUSION: Topical application of GSNO-containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re-epithelialization and affects granulation tissue organization.     

Evolution with age of the acetylcholinesterase activity in rectal suction biopsy in Hirschsprung's disease

The acetylcholinesterase (AChE) activity in Hirschsprung's disease was analyzed for histochemical patterns according to age. Its evolutional nature was also assessed. Two hundred thirty children (0 to 16 years of age) with acute or chronic obstipation were submitted to rectal suction biopsy for AChE histochemical staining. One hundred nineteen of them showed abnormal AChE activity. Retrospective analysis of those cases permitted us to establish three histochemical patterns: Pattern I, thick nerve trunks present only in the submucosa and, characteristically, absence of AChE activity in the lamina propria. This pattern was predominant in newborn up to 3 months of age and was designated the newborn pattern. Pattern II, thin nerve fibers in the muscularis mucosae and submucosa with a clear infiltration in the lamina propria. This pattern was mainly seen in children older than 1 year of age and was called classical pattern. Pattern III, an intermediate pattern showing morphologic characteristics of the two previous patterns with predominance of one or another, according to the age. A prospective study was also made in 15 children with Hirschsprung's disease who were submitted to suction rectal biopsies at different ages. In this study, a clear evolutional character of the AChE activity was observed from the newborn pattern to the intermediate and finally to the classical pattern.