Bone regeneration in extraction sites after immediate placement of an e-PTFE membrane with or without a biomaterial. A report on 12 consecutive cases.

The efficacy in restoring a buccal dehiscence after tooth extraction has been studied in 12 consecutive cases using guided bone regeneration with (6 patients) or without (6 patients) a biomaterial (DFDBA or Bio Oss) beneath an e-PTFE membrane. A correlation between the clinical impression of density at drilling time and the histological signs of bone formation has been evaluated too. The membrane was removed after 6 or 9 months and a biopsy was performed. Clinically, GBR was highly predictable for regeneration of the alveolar bone after tooth extraction with buccal dehiscence. The histology fully confirmed the clinical and radiographical results, showing bone formation in all cases with individual variations in the amount of bone formed. 6-month biopsies from the membrane sites had lamellar bone with large medullary spaces, while a good bone density was observed at 9 months. The membrane/biomaterial sites demonstrated mineralization and large amounts of allograft at 6 months. Thus, bone regeneration seems to take more time when grafting material is used.

The safety and tolerance of xanomeline tartrate in patients with Alzheimer's disease.

Xanomeline tartrate (active ingredient xanomeline) is a muscarinic agonist that has demonstrated specificity for the M1 receptor in preclinical studies and has been well tolerated at dosages up to 50 mg three times a day in healthy elderly subjects. To define the maximum tolerated dose (MTD) of xanomeline tartrate in patients with Alzheimer's disease, 48 patients (20 men, 28 women) with probable Alzheimer's disease were enrolled in a double-blind, placebo-controlled inpatient study to determine the safety and tolerability of 8 fixed dosages of xanomeline tartrate (25, 35, 50, 60, 75, 90, 100, and 115 mg, all three times a day) given for 7 days. For each dosage the treatment panel consisted of six patients (four taking xanomeline tartrate and two taking placebo). With the discontinuation of two patients because of severe intolerable adverse events, a minimum intolerated dose was reached at 115 mg three times a day, and 100 mg three times a day was defined as the MTD. This MTD in patients was two-fold greater than the MTD previously determined in healthy elderly volunteers.

Lactate oxidation and sodium reabsorption by dog kidney in vivo.

Lactate uptake (Qlact) and oxidation (QCO2lact), oxygen consumption (QO2) and net tubular Na+ reabsorption (TNa), were estimated in pentobarbital-anesthetized dogs under control conditions and following unilateral intrarenal injection of ouabain or intravenous infusion of acetazolamide, ethacrynic acid, or furosemide. QCO2lact accounted for approximately half of simultaneous Qlact and for about one-third of QO2 in control periods. Ouabain injection resulted in significant decreases in several functions of the injected kidney: TNa, 46%; TNa/FNa, 36%; QO2, 40%; Qlact, 59%; and QCO2lact, 70%. Acetazolamide infusion decreased TNa, 33%; TNa/FNa, 12%; QO2, 10%; and QCO2lact, 38%; but did not change Qlact. Ethacrynic acid diminished TNa, 60%; TNa/FNa, 36%; QO2, 45%; Qlact, 31%; and QCO2lact, 73%. Furosemide lowered TNa, 37%; TNa/FNa, 28%; QO2, 25%; and Qlact, 48%; but did not change QCO2lact, 2%. Results indicate that decarboxylation is a major pathway of renal lactate metabolism, that lactate oxidation is a substantial source of aerobic energy for the kidney, and that QCO2lact is probably functionally related to sodium reabsorption. This relationship appears to be closer for a fraction of TNa associated with ouabain- and ethacrynic acid-sensitive mechanisms.