Effects of undernutrition on myelination in rat corpus callosum

Rats were undernourished by halving the mother's food intake from the sixth day of pregnancy onwards and through lactation. Subsequently, the young animals were maintained up to 48 days on half the normal diet. The effects of this regime of treatment on myelination in the corpus callosum were investigated by light and electron microscopy. In comparison with controls, the percentage of axons myelinated at 15, 21, and 48 days was reduced in undernourished rats. The number of lamellae constituting the myelin sheath was also reduced at 15 and 21 days, but at 48 days no difference was seen between control and treated rats, suggesting that a catch-up in myelination had occured. A linear relationship between myelin sheath thickness and axonal diameter was observed in both groups of animals. However, a long-term effect on axonal growth was suggested by findings in the 48-day undernourished animals; in comparison with controls, axonal diameter was reduced, relative to myelin sheath thickness.     

Effects of obstruction on renal functions

Following ureteral obstruction there is a progressive fall in glomerular filtration rate (GFR) due to a reduction in single nephron glomerular filtration rate (SNGFR) and a reduced number of filtering nephrons. Renal plasma flow also declines after a transient, prostaglandin-dependent increase, due to afferent and efferent arteriolar vasoconstriction. The vasoactive hormones thromboxane A₂ and angiotensin II are implicated in the pathogenesis of the vasoconstriction following ureteral obstruction and they also reduce the glomerular ultrafiltration coefficient by causing mesangial contraction. Ureteral obstruction also leads to profound changes in renal tubular cell function. These include altered sodium and water handling resulting in a post-obstructive diuresis and natriuresis and a failure to dilute or concentrate the urine. Potassium and divalent cation exchange is also affected, as is urinary acidification. Furthermore, the response of the tubule to hormones such as antidiuretic hormone and parathyroid hormone is impaired. The pathophysiology of these alterations in renal function is discussed.     

Implant breast reconstruction using acellular dermal matrix

Thirteen breast reconstructions in 11 patients, averaging 58 years of age, underwent mastectomies. The technique uses a saline implant either totally or partially covered with a human acellular dermal matrix. The mean postoperative follow-up time was 14 months. Ninety percent of the patients were considered high risk; the thickness of the human acellular dermal matrix was an average of 1.3 mm, with an average area per breast of 121 cm. There were 12 successful breast reconstructions (92%) that provided stability, increased soft tissue padding, which allowed a greater resemblance to normal breast shape and decreased rippling and implant visibility. The graft was used in an onlay fashion or as an extension of the pectoralis major muscle that covers the implant. A representative histologic cross-section of well-integrated human acellular dermal matrix is presented.The use of a human acellular dermal matrix in breast reconstruction is an alternative protocol in high-risk patients, resulting in a minimal increase in operative time and a decrease in morbidity compared with more extensive procedures.     

In vivo host interactions with mineral trioxide aggregate and calcium hydroxide: inflammatory molecular signaling assessment

Introduction

Mineral trioxide aggregate (MTA) and calcium hydroxide [Ca(OH)₂] are promising biomaterials for stimulating dentinogenesis and cementogenesis. This research was undertaken to understand how MTA and CA(OH)₂ participate in the inflammatory, healing, and biomineralization processes. In this part of the study, we evaluated inflammatory signaling molecules promoted by in vivo host interaction with MTA and Ca(OH)₂.

Methods

Human dentin tubes were filled with ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), Ca(OH)₂, or kept empty. After 12 hours and 1, 3, 7, 15, 30, and 60 days of implantation in subcutaneous tissues in the backs of mice, the tubes and surrounding tissues were retrieved for cytokine level quantification and histological and immunohistochemical analysis.

Results

MTA and Ca(OH)₂ induced proinflammatory cytokine up-regulation for up to 3 days. Moreover, interleukin-10 overexpression was noted on the tissue in contact with the biomaterials during the acute phase of the inflammatory reaction. Immunohistochemical analyses showed an increased expression of myeloperoxidase, nuclear factor kappa B (NF-κB), cyclooxygenase-2, inducible nitric oxide synthase enzymes, and vascular endothelial growth factor on day 1 for all groups.

Conclusions

MTA and Ca(OH)₂ increased the activation of the NF-κB signaling system on day 1 for all groups. This finding can be associated with a proinflammatory and pro-wound healing environment, which was promoted earlier by MTA.     

Primary teeth show less protecting factors against root resorption

International Journal of Paediatric Dentistry 2011; Background. Physiological root resorption differentiates primary from permanent teeth. The understanding of what protects and regulates root resorption might help to develop therapies to its control. Aim. To verify the presence and distribution of ECRM and the expression of CK14, OPG, TRAP and COX‐2 in the periodontal ligament (PDL) of human primary and permanent teeth. Design. Eight primary teeth undergoing physiological or pathological root resorption and 4 permanent teeth were immunohistochemically processed for CK14, TRAP, COX‐2 and OPG expression. Results. PDL from primary and permanent teeth showed similar morphological features; however, fewer ECRM clusters and higher immunoreactivity to CK14 were found in primary PDL. In permanent teeth, ECRM were distributed along the entire PDL tissue. Howship′s lacunae were found only in primary teeth, associated with the presence of TRAP‐positive cells and increase in COX‐2 expression. OPG expression in primary PDL was detected in nonresorptive cervical areas and in lacunae showing reparative tissue. It was observed higher expression of OPG in all permanent teeth when compared to primary specimens. Conclusions. It may be concluded that PDL from primary teeth shows less ECRM clusters and lower expression of OPG. These features may be associated with lower protection against root resorption in primary teeth.     

Cholesterol concentrations in patients with Anorexia Nervosa and in healthy controls

Argentinean women have one of the highest international mortality rates for cardiovascular disease and they are particularly vulnerable to eating pathologies. Cardiovascular risk is exacerbated in women with Anorexia Nervosa (AN), since high cholesterol concentrations have been widely reported. OBJECTIVES: To compare blood cholesterol concentrations in AN patients with controls, and to correlate cholesterol with the body mass index (BMI), patient age, vomiting and tobacco. DESIGN AND METHOD: Cholesterol measurements documented at diagnosis from the clinical notes of patients were recorded from the Association Against Bulimia and Anorexia (ALUBA). Comparison was carried out with data of the general Argentinean public. RESULTS: Total cholesterol, LDL and HDL concentrations were higher in patients compared with controls. Total cholesterol in patients decreased during treatment and it was correlated with the patient age, but with no other variable. CONCLUSION: The abnormal lipid profile places patients at risk for cardiovascular disease. Older and untreated patients may be at particular higher risk of suffering from the consequences of elevated cholesterol concentrations.