Immunophenotypic characterization and distribution of dendritic cells in odontogenic cystic lesions

Oral Diseases (2012) 19 , 85–91 Objective: To analyze the expression and distribution patterns of mature dendritic cells (mDCs) and immature DCs (imDCs) in radicular cysts (RCs), dentigerous cysts (DtCs), and keratocystic odontogenic tumors (KCOTs). Materials and methods: Forty‐nine odontogenic cystic lesions (OCLs) (RCs, n = 20; DtCs, n = 15; KCOTs, n = 14) were assessed using the following markers: S100, CD1a and CD207 for imDCs; and CD83 for mDCs. Results: Almost all cases were S100, CD1a, and CD207 positive, whereas 63% were CD83 positive. RCs presented greater number of immunostained cells, followed by DtCs, and KCOTs. The number of S100+ cells was greater than both CD1a+ and CD207+ cells (P < 0.001), which showed approximately similar amounts, followed by lower number of CD83+ cells (P < 0.001) in each OCL type. Different from S100+ cells, both CD1a+ and CD207+ cells on the epithelium (P < 0.05) and CD83+ cells on the capsule (P < 0.05) were preferentially observed. In RCs, significant correlation was found between the thickness epithelium with S100+ and CD1a+ cells, and between the degree of inflammation with CD83+ cells. Conclusions: Dendritic cell populations in OCLs can be phenotypically heterogeneous, and it could represent distinct lineages and/or functional stages. It is suggested that besides DC‐mediated immune cell interactions, DC‐mediated tissue differentiation and maintenance in OCLs should also be considered.     

Structural abnormalities and persistent complaints after an ankle sprain are not associated: an observational case control study in primary care

Background

Persistent complaints are very common after a lateral ankle sprain.

Aim

To investigate possible associations between structural abnormalities on radiography and MRI, and persistent complaints after a lateral ankle sprain.

Design and setting

Observational case control study on primary care patients in general practice.

Method

Patients were selected who had visited their GP with an ankle sprain 6–12 months before the study; all received a standardised questionnaire, underwent a physical examination, and radiography and MRI of the ankle. Patients with and without persistent complaints were compared regarding structural abnormalities found on radiography and MRI; analyses were adjusted for age, sex, and body mass index.

Results

Of the 206 included patients, 98 had persistent complaints and 108 did not. No significant differences were found in structural abnormalities between patients with and without persistent complaints. In both groups, however, many structural abnormalities were found on radiography in the talocrural joint (47.2% osteophytes and 45.1% osteoarthritis) and the talonavicular joint (36.5% sclerosis). On MRI, a high prevalence was found of bone oedema (33.8%) and osteophytes (39.5) in the talocrural joint; osteophytes (54.4%), sclerosis (47.2%), and osteoarthritis (55.4%, Kellgren and Lawrence grade >1) in the talonavicular joint, as well as ligament damage (16.4%) in the anterior talofibular ligament.

Conclusion

The prevalence of structural abnormalities is high on radiography and MRI in patients presenting in general practice with a previous ankle sprain. There is no difference in structural abnormalities, however, between patients with and without persistent complaints. Using imaging only will not lead to diagnosis of the explicit reason for the persistent complaint.     

Medical-dental findings and management of a child with infantile Refsum disease: a case report

Infantile Refsum disease (IRD) is a peroxisome biogenesis disorder (PBD), and is part of a larger group of diseases called leukodystrophies, which are inherited conditions that damage the white matter of the brain and affect motor movements. Multiple signs and symptoms of IRD begin in infancy and progress through early childhood, including hearing and visual impairment, intellectual and growth impairment, seizures, liver involvement, and orofacial and dental abnormalities. This paper presents a case history of a 12-year-old female patient with IRD who underwent dental rehabilitation in the operating room under general anesthesia and includes a 2-year follow-up. Medical, dental, and management considerations in the care of this child's condition are presented. This paper also discusses the importance of a multidisciplinary approach in the management of children with special needs.     

Hand-sewn gastrojejunostomy using knotless unidirectional barbed absorbable suture during laparoscopic gastric bypass

Background

This report describes the authors’ institutional experience using knotless unidirectional barbed absorbable suture to close the common enterotomy of the jejunojejunostomy (JJ) and to create a hand-sewn gastrojejunostomy (GJ) during laparoscopic Roux-en-Y gastric bypass.

Methods

A retrospective review of morbidly obese patients who underwent laparoscopic gastric bypass with a hand-sewn GJ between April 2011 and 2012 was performed. The authors’ traditional technique (TT) consisted of using standard monofilament absorbable suture to close the common JJ enterotomy in a single running layer and to create the GJ with a two-layer anastomosis. A novel technique (NT) was introduced using knotless unidirectional barbed monofilament absorbable suture to perform both tasks. A comparison between these two techniques was performed.

Results

In this study, 84 patients with a mean body mass index of 41.7 ± 4.7 kg/m² underwent laparoscopic gastric bypass using a hand-sewn technique. For the 84 patients, 75 primary procedures (89.3 %) and 9 revisional procedures (10.7 %) were performed. In 38 procedures (45.2 %), the TT was used, whereas 46 cases (54.8 %) were managed using the NT. For the primary procedures, the average operating room times were slightly faster in the NT group (178.9 ± 44.4 vs 154.2 ± 74.7 min; p = 0.08). The average hospital length of stay was comparable between the two groups (2.3 ± 0.7 vs 2.6 ± 1.4 days; p = 0.25). A 30-day follow-up assessment was obtained for all 84 patients, without a significant difference in the overall complication rate between the two groups (TT 18.4 % vs NT 13 %; p = 0.77). No complications were secondary to the JJ closure or gastrojejunostomy. The complications included bleeding (n = 1), small bowel obstruction (n = 1), dehydration (n = 2), esophagitis (n = 1), and subarachnoid hemorrhage (n = 1). No anastomotic leak or stenosis occurred in either group. The mean percentage of excess weight loss at 1 month was 21.3 % ± 5.4 %, without a significant difference between the two groups.

Conclusion

In the study cohort, the use of knotless unidirectional barbed suture instead of traditional monofilament absorbable suture had similar 30-day outcomes and appears to be a feasible option for laparoscopic bowel closure and anastomosis creation.     

Common roots: a contextual review of HIV epidemics in black men who have sex with men across the African diaspora

Pooled estimates from across the African diaspora show that black men who have sex with men (MSM) are 15 times more likely to be HIV positive compared with general populations and 8·5 times more likely compared with black populations. Disparities in the prevalence of HIV infection are greater in African and Caribbean countries that criminalise homosexual activity than in those that do not criminalise such behaviour. With the exception of US and African epidemiological studies, most studies of black MSM mainly focus on outcomes associated with HIV behavioural risk rather than on prevalence, incidence, or undiagnosed infection. Nevertheless, black MSM across the African diaspora share common experiences such as discrimination, cultural norms valuing masculinity, concerns about confidentiality during HIV testing or treatment, low access to HIV drugs, threats of violence or incarceration, and few targeted HIV prevention resources.     

Renal Phosphate Wasting in the Absence of Adenylyl Cyclase 6

Parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) enhance phosphate excretion by the proximal tubule of the kidney by retrieval of the sodium-dependent phosphate transporters (Npt2a and Npt2c) from the apical plasma membrane. PTH activates adenylyl cyclase (AC) through PTH 1 receptors and stimulates the cAMP/PKA signaling pathway. However, the precise role and isoform(s) of AC in phosphate homeostasis are not known. We report here that mice lacking AC6 (AC6^−/−) have increased plasma PTH and FGF-23 levels compared with wild-type (WT) mice but comparable plasma phosphate concentrations. Acute activation of the calcium-sensing receptor or feeding a zero phosphate diet almost completely suppressed plasma PTH levels in both AC6^−/− and WT mice, indicating a secondary cause for hyperparathyroidism. Pharmacologic blockade of FGF receptors resulted in a comparable increase in plasma phosphate between genotypes, whereas urinary phosphate remained significantly higher in AC6^−/− mice. Compared with WT mice, AC6^−/− mice had reduced renal Npt2a and Npt2c protein abundance, with approximately 80% of Npt2a residing in lysosomes. WT mice responded to exogenous PTH with redistribution of Npt2a from proximal tubule microvilli to intracellular compartments and lysosomes alongside a PTH-induced dose–response relationship for fractional phosphate excretion and urinary cAMP excretion. These responses were absent in AC6^−/− mice. In conclusion, AC6 in the proximal tubule modulates cAMP formation, Npt2a trafficking, and urinary phosphate excretion, which are highlighted by renal phosphate wasting in AC6^−/− mice.Parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) are the primary regulators of renal phosphate (P_i) excretion by the proximal tubule and critically involved in the regulation of P_i balance and maintenance of plasma P_i. PTH acts on the proximal tubule through the G_s protein-coupled PTH 1 receptor (PTH₁R) to stimulate adenylyl cyclase (AC) and, thus, the synthesis of cAMP and consecutive activation of protein kinase A (PKA).^1–3 After activation of PTH₁R, the sodium-phosphate cotransporters Npt2a and Npt2c (approximately 70% and approximately 30% reabsorption of filtered P_i, respectively) are retrieved from the apical plasma membrane, resulting in increased P_i excretion.^4–6 In addition, cAMP-independent effects of PTH have been reported,⁷ which may involve PTH₁R action on phosphoinositide-specific phospholipase C (PLC)^8,9 and mitogen-activated protein kinases.^10,11 FGF-23 mediates its action in the proximal tubule through the FGF receptor/Klotho complex, which downregulates the expression of Npt2a and Npt2c.^12,13 Immunohistochemistry identified Npt2a to be localized predominantly in the apical plasma membrane of S1–S3 segments of the proximal tubule.^6,14,15 Npt2c has a similar cellular distribution with greater abundance in S1 segments.^5,16,17Genetic defects in G_sα result in impaired PTH-induced retrieval of Npt2a, resulting in a failure to respond with increased urinary P_i excretion: a disease commonly referred to as pseudohypoparathyroidism type Ia or Ib (depending on the presence or absence of skeletal defects, respectively).^18–20 In comparison, less is known about the role of AC proteins in mediating the signaling between PTH₁R and Npt2a and/or Npt2c. Generation of cAMP involves the activation of ACs, of which nine different membrane-bound isoforms have been identified (AC1–AC9).²¹ Studies on AC isoform mRNA expression in rat kidney showed that, except for AC1 and AC8, all AC isoforms are expressed.^22–24 In mice where a green fluorescent protein reporter gene was expressed under the control of the AC6 promoter, green fluorescent protein-positive cells were found in cells of the proximal tubules, thick ascending limbs, distal tubules, and collecting ducts.²⁵ Functional studies have shown a role of AC6 in the thick ascending limb, distal tubule, and collecting duct insofar as mice lacking AC6 have Bartter syndrome²⁶ and nephrogenic diabetes insipidus (NDI).^27,28 In a collecting duct-specific AC6 knockdown model, vasopressin-stimulated epithelial sodium channel open probability was abolished.²⁹Based on studies indicating that vasopressin V₂ receptors use the AC6–cAMP signaling pathway^26–30 and the relatively high abundance of AC6 in the proximal tubule,^23,30,31 we proposed that AC6 may contribute to PTH-stimulated cAMP formation, P_i excretion, and thus, P_i homeostasis. In the present study, we examined P_i homeostasis, PTH-induced renal excretion of P_i and cAMP, and trafficking and expression of Npt2a and Npt2c in mice lacking AC6 (AC6^−/−). The results show that AC6^−/− mice have renal phosphate wasting, and thus, AC6 has an essential contribution to PTH actions, cAMP formation, and renal P_i excretion in vivo.