Orientation of retentive matrices on spherical attachments independent of implant parallelism.

Traditionally, it has been advocated that implants planned for use as overdenture abutments be placed parallel to each other to obtain predictable attachment retention and complete seating of the restoration and to prevent premature wear of components. However, it is often difficult or impossible to place implants parallel to each other, and patients with implants that have already been placed in a variety of positions frequently are referred to restorative dentists. This article describes a technique for the fabrication of a matrix-paralleling device as well as 2 of its uses. The device allows proper orientation of the retentive matrices to establish a common path of withdrawal for the prosthesis and all attachments. Provided that the matrices are parallel to each other, spherical overdenture attachments can be used even when the implants are not parallel.

[Acute kidney failure in a recurrence of sarcoidosis at the height of summer]. / Akutes Nierenversagen bei Sarkoidose-Rezidiv im Hochsommer.

HISTORY AND FINDINGS: A 35-year-old woman with sarcoidosis, successfully treated 3 years previously, developed fatigue, nausea and loss of weight during a summer holiday in Italy where she was exposed to much bright sun. There had been no previous recurrence of the sarcoidosis. On return she was found to be in renal failure with marked hypercalcaemia. Physical examination merely revealed peasized non-tender submandibular and cervical lymph nodes, but was otherwise unremarkable. INVESTIGATIONS: Serum creatinine and calcium concentrations (3.8 mg/dl and 3.6 mmol/l) were markedly elevated. Computed tomography showed an enlarged submandibular lymph node, but no other organ abnormality. Biopsy of the salivary gland demonstrated recurrent sarcoidosis. TREATMENT AND COURSE: Calcium concentration became normal (2.4 mmol/l) within two weeks of treatment with methylprednisolone (100 mg daily for 3 days, followed by gradual reduction to 30 mg daily for 3 months, until discontinued slowly). Creatinine concentration, which had fallen to 1.5 mg/dl, was at the upper limit of normal (1.1 mg/dl) after 4 months and 0.8 mg/dl after 8 months. CONCLUSION: Marked exposure to UV light should be avoided in patients with a history of recent sarcoidosis, because it increases the formation of vitamin D3 precursors: In the case of recurrent sarcoidosis, these precursors are converted to 1,25 dihydroxyvitamin D3 in the sarcoidosis granulomas. This can lead to severe complications, such as hypercalcaemia and renal failure.

Non-invasive oscillometric wrist and upper arm blood pressure measurements compared with invasive values.

In 100 patients invasive blood pressure (BP) measurements in the aortic arch were compared with oscillometric devices at the left upper arm (UA1, device: Hestia OZ 80) and at the left and right wrists (Wl, Wr, device: NAiS Blood Pressure Watch). BPs/BPd at Wl were on average 4.3/6.0 mmHg higher than aortic BP with a relative high variability. Difference between Wls and Aos more than +/- 20 mmHg in 16% of patients between Wld and Aod more than +/- 20 mmHg in 5% of patients. Within the limits of +/- 10 mmHg, we found 56% of the systolic and 74% of the diastolic wrist values compared to the aorta. The automatic oscillometric BP measurement at the wrist is a useful method for BP self-measurement, but should be compared with upper arm values before recommending it (difference < +/- 10 mmHg) in the individual case.

[Comparison of invasive blood pressure measurement in the aorta with indirect oscillometric blood pressure measurement at the wrist and forearm]. / Vergleich von invasiver Blutdruckmessung in der Aorta mit indirekter oszillometrischer Blutdruckmessung an Handgelenk und Oberarm.

Indirectly measured blood pressure at the wrist or upper arm was compared with directly measured values in the aortic arch during routinely performed diagnostic cardiac catheterization in 100 patients (31-80 years, mean 59.3 years, 60% males). The noninvasive measurements were carried out by oscillometric devices, NAiS Blood Pressure Watch for measurements at the wrist, and Hestia OZ80 at the upper arm. Systolic blood pressure measured at the wrist was 4.3 +/- 14.1 mm Hg, and the diastolic value 6.0 +/- 8.9 mm Hg higher than when measured at the aortic arch; the difference was significant in both cases. Correlation coefficients were 0.85 for systolic and 0.71 for diastolic blood pressure. In 16% of the patients the systolic blood pressure at the wrist differed more than +/- 20 mm Hg. The diastolic blood pressure at the wrist measured more than +/- 20 mm Hg higher than in the aorta in 5% of the patients. At the upper arm mean systolic values were not different to the aorta. The diastolic pressure was 9.3 +/- 9.8 mm Hg higher in the aorta than at the upper arm. To verify the accuracy of values measured with the NAiS Blood Pressure Watch compared with the standard technique at the upper arm, sequential measurements were made at wrist and ipsilateral upper arm in the same group of 100 patients. The systolic blood pressure at the left wrist was 3.4 +/- 13.3 mm Hg higher and the diastolic pressure 3.8 +/- 9.5 mm Hg lower than at the upper arm. Only 53% of systolic values lay within a range of +/- 10 mm Hg. The correspondence between wrist and upper arm values was better for diastolic blood pressure, the values differing by less than +/- 10 mm Hg in two-thirds of patients. Self-measurement of arterial blood pressure with an oscillometric device at the wrist can be recommended only in individual cases with a difference of simultaneously measured values at the upper arm of less than +/- 10 mm Hg for systolic and diastolic blood pressures. The standard method for indirectly measuring arterial blood pressure remains the measurement at the upper arm site, which nevertheless showed a systolic pseudohypertension (deviation of more than 10 mm Hg) in comparison to the invasively measured values in 15% of our selected patients and a diastolic pseudohypertension (deviation of more than 15 mm Hg) in 23% of the patients.

Metabolism of cysteinyl leukotrienes by the isolated perfused rat kidney.

The metabolism of cysteinyl leukotrienes by the isolated perfused rat kidney was investigated. For this purpose LTC4, LTD4 or LTE4 were studied in separate experiments. The isolated perfused rat kidney metabolized all cysteinyl leukotrienes to the final metabolite N-acetyl-LTE4. In the presence of 5% albumin 50% of LTC4 was metabolized to LTD4 (22%), LTE4 (15%) and N-acetyl-LTE4 (13%) within 60 min. Excretion of radioactivity into urine was less than 1%. In contrast, in the absence of albumin, LTC4 was completely metabolized within 45 min to N-acetyl-LTE4, the sole and final metabolite of LTC4 found in the perfusion medium as well as in urine. After 60 min 19% and 42% of total radioactivity were found in the perfusion medium and in urine, respectively. Isolated glomeruli metabolized LTC4 to LTD4 and to LTE4 but not to N-acetyl-LTE4 at a rate comparable to the rate observed by the isolated perfused kidney in the absence of albumin. In contrast to isolated glomeruli isolated tubuli metabolized LTE4 to N-acetyl-LTE4 at a rate comparable to that observed by the isolated perfused kidney in the absence of albumin. The present study shows that the isolated perfused rat kidney metabolizes cysteinyl leukotrienes to the sole and final metabolite N-acetyl-LTE4. In the presence of albumin metabolism is slowed down and excretion of N-acetyl-LTE4 into urine is prevented.

LTB4 in nephrotoxic serum nephritis in rats.

We studied leukotriene B4 (LTB4) synthesis in isolated glomeruli of rats with nephrotoxic serum nephritis. This nephritis was induced in male Sprague Dawley rats by injecting one proteinuric dose of nephrotoxic serum (rabbit anti-rat-GBM serum) after prior immunization of the rats with rabbit IgG. Histological and analytical examinations were performed in kidneys perfused until free of blood 6, 12, 24, 48 and 72 hours after induction of the disease. To investigate LTB4 production, glomeruli were isolated and incubated for one hour in the presence of Ca++-ionophore A23187. The supernatants were analyzed for LTB4. The peak comigrating on reverse-phase high performance liquid chromatography (RP-HPLC) with reference LTB4 was isolated. The ethyl ester trimethylsilyl ether derivative of this peak was analyzed by gaschromatography-mass spectrometry (GC/MS). Identical spectra of the glomerular samples and of reference LTB4 in the positive and in the negative ion chemical ionization mode provided unequivocal evidence that the substance released from the nephritic glomeruli was indeed LTB4. Six hours after injection of nephrotoxic serum, glomerular LTB4 release was highest with 5.52 +/- 0.50, then declining to 2.20 +/- 0.10 ng/mg glomerular protein at 12 hours. At 24, 48 and 72 hours no statistically significant difference from control animals was found. No metabolism of LTB4 to 20-hydroxy- or 20-carboxy-LTB4 was detected during the incubation period. Albuminuria developed during the first 24 hours after nephrotoxic serum challenge and rose steadily throughout the observation period up to 277 +/- 25 mg/24 hr after 72 hours.(ABSTRACT TRUNCATED AT 250 WORDS)