Submental cutaneous sinus tract as a result of progressive peri-implantitis: a case report

BACKGROUND: The aim of the present case report was to define diagnosis and treatment options of a submental cutaneous sinus tract as a result of a progressive peri-implantitis around mandibular dental implants in a patient with a history of oral squamous cell carcinoma. METHODS: Before the removal of the submental fistula, a panoramic radiograph and a computed tomography of the head and neck were assessed to identify the implants responsible for the cutaneous sinus tract and to exclude the presence of a tumor recurrence and lymph node metastases. The involved implants were removed, as there was a communication along them between the oral cavity and the cutaneous sinus tract resulting from progressive peri-implantitis. A histological examination of the excised fistula was carried out. RESULTS: The histological examination excluded a recurrence of the oral squamous cell carcinoma. The fistula completely consisted of granulation tissue without epithelialization. After affected implants were removed, the wound healing was uneventful. CONCLUSIONS: A panoramic radiograph is mandatory to identify the involved implants. Computed tomography, and excision of the fistula and a histological examination should be performed only in patients with a history of oral squamous cell carcinoma. Since the cutaneous sinus tract showed no epithelialization, it healed spontaneously after the removal of the responsible implants. Because of the large bony defect caused by progressive peri-implantitis leading to a communication of the oral cavity with the cutaneous sinus tract, more conservative treatment options with preservation of the implants could not be adopted in the present case.     

An evaluation of the predictive validity and reliability of ventilatory threshold

PURPOSE: To identify a valid and reliable method to determine 40-km time trial (40K) performance in a laboratory setting. METHODS: Part 1: Ventilatory threshold (VT) and 40K performance were determined on two occasions (February/September) using two subsets of cyclists (N = 15 each; VO(2max) 67.6 +/- 4.2/71.5 +/- 3.0 mL x kg(-1) x min(-1)) to determine the predictive validity of VT assessments. Variables of interest were power output at VT, peak power output (MaxVT(w)), and average power output during 40K (40K(avgwatts)). For VT determination we used: breakpoint of VE/VO2; breakpoint of VE/VCO2; V-slope; RER = 1; and RER = 0.95. In part 2, test-retest reliability of VT and MaxVT(w) were examined in 20 subjects (VO(2max) 64.8 +/- 8.0 mL x kg(-1) x min(-1)) on two occasions, separated by 48 h. RESULTS: Regression analyses between power outputs at VTs and 40K(avgwatts) showed significant predictive validity for (February/September): V-slope (r = 0.79/0.84; SEE 155/13.3W), VE/VO2 (r = 0.80/0.81; SEE 15.2/14.2W), RER0.95 (r = 0.73/0.58; SEE 17.4/21.2W), RER1 (r = 0.75/0.74; SEE 16.8/16.7W), and MaxVT(w) (r = 0.81/0.73; SEE 15.0/17.1W). Paired t-tests between power outputs at VTs and the 40K(avgwatts) indicated that mean power outputs at VE/O2 (261 +/- 29W; P = 0.33) and RER0.95 (274 +/- 55W; P = 0.93) in February and VE/VO2 (274 +/- 37W; P = 0.79) in September were not significantly different from the respective 40K(avgwatts) (277 +/- 30W/281 +/- 30W). Test-retest reliability analysis yielded the following intraclass correlation and relative test-retest errors: V-slope: 0.98, 2.6%; VE/VO2: 0.95, 5.3%; RER0.95: 0.87, 9.8%; RER1: 0.94, 5.7%; VE/VCO2: 0.87, 12.1%; MaxVT(w): 0.98, 2.6%. CONCLUSION: The high test-retest reliability and consistent ability to accurately predict athletes' 40K(avgwatts) across a competitive season indicated that VE/VO2 was superior to the other evaluated methods.     

Medical research in paediatrics: ethical issues

Since 1947 (the Nuremberg Code), the ethics of experimentation on human beings is based on the principle of the informed consent of the subjects participating in the research. In this context, research in paediatrics raised particular and difficult problems. International regulations have evolved in a way that has permitted paediatric research, within strict limits. However, recent studies have shown that the level of clinical paediatric research remains weak. There are economic reasons for this. But it also reveals the persistence of an ethical conflict: some people fear that a relativisation of the principle of consent (proxy consent) will lead to weakened protection for the most vulnerable subjects, including children. The ethics of responsibility requires a balance between the protection of the child as an individual (who should never become a medical guinea-pig) and the protection of children as a group (who should never be deprived of the benefits of the medical research).     

Nierenbefunde bei Paraproteinämien und fibrillären Glomerulopathien

The term “paraproteinemia” or dysproteinemia” refers to a group of diseases caused by specific proteins that very often leads to kidney disease. In these cases a kidney biopsy is often the first diagnostic procedure leading to the diagnosis of a systemic disease. Due to the very variable presentation of the kidney disease in paraproteinemias a diagnosis is often very difficult without specific clinical data. Therefore, we recommend systematic investigation of the kidney biopsy including routine immunohistochemical stains for κ- and λ-light chains and electron microscopy in elderly patients with proteinuric kidney disease of unknown origin. In the following we will briefly discuss renal manifestations and clinical symptoms in multiple myeloma with light- or heavy chain deposition (LCDD: light chain deposition disease, HCDD: heavy chain deposition disease), macroglobulinemia Waldenström (Morbus Waldenström), primary amyloidosis or so called monoclonal gammopathy of uncertain dignity (benign monoclonal gammopathy) and fibrillary glomerulopathies.     

The effects of nifedipine on ventricular fibrillation mean frequency in a porcine model of prolonged cardiopulmonary resuscitation

We assessed the effects of a calcium channel blocker versus saline placebo on ventricular fibrillation mean frequency and hemodynamic variables during prolonged cardiopulmonary resuscitation (CPR). Before cardiac arrest, 10 animals were randomly assigned to receive either nifedipine (0.64 mg/kg; n = 5) or saline placebo (n = 5) over 10 min. Immediately after drug administration, ventricular fibrillation was induced. After 4 min of cardiac arrest and 18 min of basic life support CPR, defibrillation was attempted. Ninety seconds after the induction of cardiac arrest, ventricular fibrillation mean frequency was significantly (P < 0.01) increased in nifedipine versus placebo pigs (mean +/- SD: 12.4 +/- 2.1 Hz versus 8 +/- 0.7 Hz). From 2 to 18.5 min after the induction of cardiac arrest, no differences in ventricular fibrillation mean frequency were detected between groups. Before defibrillation, ventricular fibrillation mean frequency was significantly (P < 0.05) increased in nifedipine versus placebo animals (9.7 +/- 1.2 Hz versus 7.1 +/- 1.3 Hz). Coronary perfusion pressure was significantly lower in the nifedipine than in the placebo group from the induction of ventricular fibrillation to 11.5 min of cardiac arrest; no animal had a return of spontaneous circulation after defibrillation. In conclusion, nifedipine, but not saline placebo, prevented a rapid decrease of ventricular fibrillation mean frequency after the induction of cardiac arrest and maintained ventricular fibrillation mean frequency at approximately 10 Hz during prolonged CPR; this was nevertheless associated with no defibrillation success. IMPLICATIONS: This study evaluates the effects of a calcium channel blocker on ventricular fibrillation mean frequency, hemodynamic variables, and resuscitability during prolonged cardiopulmonary resuscitation (CPR) in pigs. Nifedipine, but not saline placebo, prevented a rapid decrease of ventricular fibrillation mean frequency after the induction of cardiac arrest and maintained ventricular fibrillation mean frequency at approximately 10 Hz during prolonged CPR but did not improve resuscitability.     

Beneficial effects of calcimimetics on progression of renal failure and cardiovascular risk factors

In renal failure, parathyroid hormone (PTH) is not only involved in the genesis of disturbed calcium/phosphate metabolism and ostitis fibrosa; it is also a permissive factor in the genesis of hypertension, cardiovascular damage, and dyslipidemia. The allosteric activator of the calcium sensing receptor NPSR-568 (R-568) has been shown to reduce the serum intact PTH (iPTH) concentration in uremic rats. It was the purpose of this study in subtotally nephrectomized (SNX) rats to compare pharmacologic abrogation of secondary hyperparathyroidism by R-568 with parathyroidectomy (PTX). The effects on progression of renal failure, BP, and lipid and structural parameters of kidney and heart were studied. Four groups of male SD-rats were studied: (1) sham-operated + vehicle-treated rats (controls); (2) SNX + vehicle-treated rats (SNX); (3) parathyroidectomized SNX + vehicle-treated rats (SNX+PTX); and (4) SNX + calcimimetic R-568-treated rats (SNX+R-568). R-568 (50 micro mol/kg per d) was administered by gavage. Eight weeks after SNX, serum creatinine concentration, urinary albumin excretion, BP, and serum LDL-cholesterol concentration were significantly lower in both R-568-treated and parathyroidectomized SNX compared with vehicle-treated SNX. In addition, structural abnormalities of the kidney (glomerulosclerosis, tubulointerstitial changes) and the heart (interstitial fibrosis, capillary length density, arteriolar wall thickness) were significantly less pronounced than in vehicle-treated SNX. It is concluded that in experimental renal failure abrogation of hyperparathyroidism by administration of a calcimimetic or PTX similarly attenuates progression of renal failure. Furthermore, it interferes with the development of cardiovascular risk factors and cardiac remodeling.     

Linking osteoarthritis-specific health-status measures to the International Classification of Functioning,Disability, and Health (ICF)

OBJECTIVES: The objective of this study was to link the Western Ontario and McMaster Universities (WOMAC) and Lequesne-Algofunctional indices to the ICF on the basis of linking rules developed specifically to accomplish this aim. The linking process enables the understanding of the relationship between health-status measures and the ICF. METHODS: Since the fifth World Health Organisation/International Liege Against Rheumatism (WHO/ILAR) Task Force and the Outcome Measures in Rheumatology Clinical Trials (OMERACT) group recommend the use of WOMAC and the Lequesne-Algofunctional indices in patients with osteoarthritis of the hip and knee in clinical trials, these two health-status measures have been used in this study.Both health-status measures were linked to the ICF separately by two trained health professionals. Consensus between health professionals was used to decide which ICF category should be linked to each item/concept of the two questionnaires. To resolve disagreements between the two health professionals, a third person trained in the linking rules was consulted. RESULTS: Except for the concept of 'morning stiffness', both health professionals agreed on the ICF category chosen to link all the items/concepts of both questionnaires. Altogether, 29 different ICF categories have been linked. Five ICF categories belong to the ICF component 'body functions', 23 categories to the component 'activities and participation', and one category to 'environmental factors'. Both questionnaires have 10 ICF categories in common. CONCLUSIONS: The results of the linking process reflect both the structure of the two questionnaires studied and the relationship between them, showing that the ICF classification can become the cardinal reference for existing health-status measures.     

Remodeling of resistance arteries in renal failure: effect of endothelin receptor blockade

Remodeling of vessels is a known feature of renal failure, but it is unclear whether this represents an appropriate or inappropriate response to the known changes in blood flow, shear stress, and wall tension. To investigate remodeling in response to variations in blood flow, first-order mesenteric arteries were exposed to high- and low-flow conditions via the ligation of second-order branches, according to the technique described by Pourageaud and De Mey. The resulting changes in vessel geometric features, relative proportions of intima and media, submicroscopic structure, and immunostaining for proliferating cell nuclear antigen (PCNA), endothelin-1 (ET-1), and ET(A) receptors were assessed in first-order mesenteric arteries under low-flow and high-flow conditions. Subtotally nephrectomized (SNX) animals were compared with sham-operated rats. Animals either were left untreated or were treated with the ET(A) receptor antagonist (ET-RA) LU-135252, because of suggestions in the literature that ET is involved in vascular remodeling in uremia. A highly significant increase in intimal thickness was noted in low-flow arteries (4.21 +/- 1.39 microm) of SNX animals, compared with normal-flow arteries (2.06 +/- 0.61 microm), but this increase was not observed in sham-operated rats (1.38 +/- 0.77 in low-flow arteries versus 2.40 +/- 0.35 microm in normal-flow arteries). The increase in intimal thickness in low-flow arteries was abrogated by ET-RA. The medial thickness was increased in untreated SNX animals (19.5 +/- 3.61 microm), compared with sham-operated rats, and this increase was also prevented by ET-RA. The medial thickness was not affected by low flow in either sham-operated or SNX animals. In parallel, the number of PCNA-positive intimal cells was higher in low-flow, but not high-flow, arteries of SNX rats, compared with sham-operated rats. No significant change was observed in sham-operated animals. In the media, the number of PCNA-positive cells was higher in untreated SNX animals than in sham-operated rats. The number was even more markedly increased in high-flow, but not low-flow, vessels. This increase was abrogated by ET-RA. It is concluded that, in uremic animals, the response of the intima to low flow and the response of the media to high flow are exaggerated. Both responses are apparently mediated by ET.