[Short- and Medium-Term Results of Total Elbow Arthroplasty after Trauma]. / Kurz- und mittelfristige Ergebnisse der Ellenbogenarthroplastik nach Trauma.

BACKGROUND: Treatment of distal humerus fractures by open reduction and internal fixation, especially in elderly patients, does not always result in satisfactory outcomes. Previous studies show good outcomes in total joint replacement of these fractures. The objective of this study is to present our experience with primary and secondary implantation of a semiconstrained elbow prosthesis after trauma. PATIENTS AND METHODS: In two study centers, between 2003 and 2009, a total of 44 patients (34 women and 10 men) with an average age of 65 years were treated primarily (n = 19) or secondarily (n = 25) by semiconstrained total elbow replacement after distal humerus fractures. Primary treatment referred exclusively to 13C2 and 13C3 fractures according to the AO/ASIF-classification, except for two cases. Indications for secondary elbow arthroplasty were post-traumatic arthrosis (n = 10), non-union of the bone (n = 6), failed osteosynthesis (n = 5), post-traumatic chronic luxation (n = 2) and severe bony defect situation after chronic osteitis (n = 2). In two cases a prostheses exchange for a periprosthetic fracture after fall was performed. Clinical outcome was radiologically controlled and measured by the use of the Mayo Elbow Performance Score (MEPS) and DASH score after a mean follow-up of 38 (13 to 96) months. RESULTS: 33 Patients (75 %) had a follow-up examination clinically and radiologically. Mayo Elbow Performance Score was excellent or good in 27 (82 %) cases with a mean of 87 points (primary group 87 vs. secondary group 86). The average DASH score was 28 points (primary group 24 vs. secondary group 32). The flexion was on average 131° (110 to 145°), the extension deficit 30° (0 to 80°) to neutral position and the range of motion was 100° (40 to 145°) (primary group 102° vs. secondary group 97°). The mean operation time was 141 (100 to 250) minutes (primary group 138 vs. secondary group 144 min.). The length of stay in hospital was on average 15 days. Complications occurred due to ulnar paresthesia (n = 4), deep infection (n = 6), periprosthetic ulna fracture (n = 1), heterotopic ossifications requiring intervention (n = 1), elbow stiffness (n = 1), triceps insufficiency (n = 5) and triceps avulsion (n = 2). CONCLUSION: Primary elbow joint replacement seems to be a promising alternative for distal humerus fractures without a sufficient reconstruction opportunity, showing encouraging short- and medium-term results in the elderly. Secondary replacement can achieve satisfying results in failed osteosynthesis, non-union of the bone or post-traumatic arthrosis as well. The rate of complications and revisions is high.

Tissue engineering of vascular conduits: fabrication of custom-made scaffolds using rapid prototyping techniques.

BACKGROUND: The technique of stereolithography, which automatically fabricates models from X-ray computed tomography or magnetic resonance imaging (MRI) data linked to computer-aided design programs, has been applied to the fabrication of scaffolds for tissue engineering. We previously reported on the application of stereolithography in scaffold fabrication of a trileaflet heart valve. In our current experiment we demonstrate a new technique for the fabrication of custom-made conduits for the potential replacement of a coarcted aortic segment. METHODS AND RESULTS: In this experiment the image data derived from a 12-year-old male patient with aortic coarctation scanned by MRI were processed by a computer-aided design program to reconstruct the aortic arch with isthmus stenosis three dimensionally. By defining the stenotic section and the adjacent normal vessel a custom-made nonstenotic descending aorta was reconstructed to replace the stenosed part. The rapid prototyping technique was used to establish stereolithographic models for fabricating biocompatible and biodegradable vascular scaffolds with the anatomic structure of the recalculated human descending aorta through a thermal processing technique. CONCLUSION: Our results suggest that the re-creation and reproduction of complex vascular structures by computer-aided design techniques may be useful to fabricate custom-made polymeric scaffolds for the tissue engineering of living vascular prostheses.

Optimization of dialysate flow and mass transfer during automated peritoneal dialysis.

The purpose of this study was to evaluate the effect of patient position on the mass transfer area coefficient (KoA) and to characterize drain/fill profiles in an effort to enhance efficiency of automated peritoneal dialysis. Over 100 exchanges were performed in 38 stable peritoneal dialysis patients to either determine the small solute KoA in the supine versus upright position or to characterize fill/drain profiles. The KoA for all solutes tested was significantly greater in the supine position compared with the upright position (P < 0.05). Fill profiles revealed the fill rate to be a function of fill height (P < 0.001) and patient position (supine > upright [P < 0.001]). Analysis of drain flow rate versus time revealed an initial segment of high outflow (350 +/- 89 mL/min) followed by an abrupt transition to a segment characterized by slow drainage (36 +/- 21 mL/min). The first segment of drain only took 5.6 +/- 2.3 minutes (42% of the total drain time); in that time, 83% +/- 10% of the dialysate was drained. The transition volume (volume of dialysate remaining at the time the transition occurs, excluding residual volume) correlated with body surface area (R = 0.52, P < 0.01). In conclusion, automated peritoneal dialysis treatment (including intermittent peritoneal dialysis, which may be done in the upright position) should be done in the supine position to optimize the KoA, and shortening drain time to include only the initial segment of high outflow will improve the efficiency and convenience of therapy.

Hepatitis C is a poor prognostic indicator in black kidney transplant recipients.

BACKGROUND: The significance of hepatitis C in kidney transplant recipients is unclear. The prevalence of antibodies to hepatitis C among candidates for transplantation is up to 50% in some centers. METHODS: We screened 640 frozen serum samples obtained pretransplantation from all kidney recipients at the Medical College of Wisconsin between January 1979 and March 1990 for antibody to hepatitis C using the second generation immunoassay. Charts were reviewed from all hepatitis C antibody-positive (anti-HCV+) patients and 256 randomly chosen hepatitis C antibody negative (anti-HCV-) controls. Actuarial patient and graft survival in these two groups were determined. RESULTS: The prevalence of anti-HCV was 8.3%. Blacks and i.v. drug users were disproportionately represented in the anti-HCV+ group. Of the anti-HCV+ patients, 18.9% developed chronic hepatitis independent of race. Black anti-HCV+ patients had a 5-year graft survival of 28 +/- 11% compared to 67 +/- 7% in black anti-HCV- patients (P = 0.003). Black anti-HCV-, white anti-HCV-, and white anti-HCV+ patients all had similar graft survival. Anti-HCV was not a poor prognostic indicator for overall patient survival or the development of aplastic anemia and malignancies including hepatocellular carcinoma. CONCLUSIONS: Anti-HCV is a significant risk factor for reduced kidney graft survival in blacks apart from i.v. drug abuse. Black anti-HCV- patients had graft survival similar to white transplant recipients, indicating that anti-HCV may be one marker for the poorer graft survival in blacks that has been observed in most transplant programs. Anti-HCV in kidney transplant recipients increases the risk for the development of chronic hepatitis post-transplant.

Histochemical carbonic anhydrase in rat inner medullary collecting duct.

Rat inner medullary collecting duct (IMCD) secretes substantial amounts of H+. However, carbonic anhydrase (CA), a concomitant of H+ secretion, has been generally reported absent in this segment. To reexamine this problem, we investigated CA and the morphological phenotypes of cells comprising the IMCD by CA histochemistry, using a modified Hansson technique with light and electron microscopy. Throughout the medulla, tubule cells exhibit histochemical CA activity. In the initial third of the inner medulla, a small proportion have features of intercalated cells and demonstrate some degree of CA activity. However, the majority population in the early portions of the IMCD appears to consist of principal cells. These also show CA staining of widely variable intensity, both among and within cells. A third cell type, previously called "IMCD cells", appears in the middle portion of the IMCD and is the only cell type present near the papilla tip. In contrast to previous reports, these "IMCD cells" have histochemical CA staining, also of highly variable intensity. These results demonstrate that stainable carbonic anhydrase to support acidification is present throughout the rat IMCD, both in intercalated cells and in some cells clearly not of this type. Therefore, the presence of CA is not specific for the intercalated cell type and suggests that other cell types may participate in acid secretion in IMCD.

Clinical outcome of continuous ambulatory peritoneal dialysis predicted by urea and creatinine kinetics.

The effectiveness of urea kinetics (Kt/V, where K is urea clearance, t is treatment time, and V is the volume of distribution for urea) to assess the adequacy of continuous ambulatory peritoneal dialysis (CAPD) and clinical outcome has not been established prospectively, and cross-sectional clinical studies have been inconclusive. A minimum weekly creatinine clearance of 40 to 50 L is recommended, but the adequacy of this dose is unproven. We introduced a simpler approach to creatinine kinetics in the form of an efficacy number (EN) calculated from data obtained in a standardized 4-h dwell exchange. To determine the most effective model for predicting CAPD adequacy, residual renal function, weekly Kt/V urea, weekly creatinine clearance standardized to body surface area, and EN (liters per gram of creatinine per day) were measured in 18 stable CAPD patients followed prospectively for at least 12 months. Patients were divided into three groups, good (G), intermediate (I), and poor (P), on the basis of uremic symptoms, mortality, hospital days, biochemical indices, and the need for transfer to hemodialysis. When comparing groups G (N = 6) and P (N = 8), weekly Kt/V were 2.3 +/- 0.2 versus 1.5 +/- 0.1 (P less than 0.005), weekly creatinine clearances were 71.5 +/- 8.6 versus 35.1 +/- 1.3 L (P less than 0.001), and EN were 7.4 +/- 0.8 versus 3.6 +/- 0.2 L/g of creatinine/day (P less than 0.005). Creatinine kinetics (weekly clearance and EN) but not urea kinetics could differentiate group I (N = 4) from groups G or P. Both urea and creatinine kinetics predict clinical outcome in CAPD.(ABSTRACT TRUNCATED AT 250 WORDS)

A review of urea and creatinine kinetics in predicting CAPD outcome.

The adequacy of the peritoneal dialysis prescription is of great concern. Although the use of urea kinetics has become the standard in hemodialysis, its usefulness in peritoneal dialysis is unclear. It has been suggested that creatinine clearance may correlate with clinical outcome in CAPD but, as with urea kinetics, its predictive value is not established. The efficacy number (EN), which only requires a four hour exchange, was introduced as a simpler approach to creatinine kinetics. These three kinetic models were correlated to clinical outcome in 18 stable CAPD patients over a 12 month study period. The patients were divided into three groups: good (G), intermediate (I), and poor (P) based on uremic symptoms, mortality, hospital days, biochemical indices and the need for transfer to hemodialysis. Both forms of creatinine kinetics (weekly creatinine clearance, EN) were able to differentiate between the G, I, and P outcome groups (P < 0.05). The weekly uea Kt/V was able to differentiate between the G and P groups (P < 0.05) but not between the I and the other two outcome groups. Both urea and creatinine kinetics predict clinical outcome in CAPD. However, creatinine kinetics may be a more sensitive predictor. The efficacy number was just as sensitive as creatinine clearance in predicting clinical outcome yet simpler to gather the data for its calculation.

Obstructive acute renal failure by a gravid uterus: a case report and review.

Acute renal failure caused from an obstruction by the gravid uterus is a rare complication of pregnancy. Only 13 cases have been reported. We report a case of obstructive acute renal failure in a patient at 34 weeks' gestation with a twin pregnancy complicated by polyhydramnios. The serum creatinine peaked at 1,078 mumol/L (12.2 mg/dL), higher than in the previously reported patients. The striking feature of her clinical course was the immediate resolution of anuria following amniotomy, thus avoiding the need for dialysis, ureteral stenting, or immediate surgical delivery. This patient illustrates the potential importance of increased uterine pressure on the ureters as a cause of significant obstructive renal failure during pregnancy.

Carbonic anhydrase in turtle bladder mitochondrial-rich luminal and subluminal cells.

Bladders from March-April turtles were processed for carbonic anhydrase (CA) cytochemically using the method of D.A. Riley, S. Ellis, and J. Bain (Neuroscience 13: 189, 1984). CA-positive cells comprised 11.1 +/- 0.7% of mucosal epithelial cells. Microplicated (MP) cells comprised 47.2 +/- 1.8% of CA-positive cells and displayed at least two distinct staining patterns: the first was characterized by reaction product that filled the luminal one-third, including the terminal web and microplicae. These cells possessed extensive microplicae, a morphological feature of ongoing H+ secretion. The second was characterized by reaction product distributed throughout cells, excluding the terminal web and microplicae, with greatest intensity in the luminal one-third below the terminal web. These cells possessed flattened microplicae, a morphological feature of diminished H+ secretion. Microvillated (MV) cells comprised 6.0 +/- 1.0% of CA-reactive cells. The basal layer was occupied by 46.8 +/- 1.7% of CA-positive cells, which were termed subluminal (SL) cells. SL cells were mitochondrial rich and did not contact the lumen. Extracellular CA staining was common between the lateral margins of contiguous mitochondrial-rich or non-mitochondrial-rich cells.

Carbonic anhydrase and proton secretion in turtle bladder mitochondrial-rich cells.

Bladders from actively feeding turtles were processed for carbonic anhydrase (CA) cytochemically. CA-positive cells were identified as microplicated (MP) cells, microvillated (MV) cells, and subluminal (SL) cells. After acute enhancement of H+ secretion with 5% CO2, MP cells displayed extensive microplicae and a reduced density of apical subplasmalemmal vesicles, and they were CA reactive throughout a large part of the cytoplasm including the microplicae. After acute inhibition of H+ secretion with a pH 4.5 mucosal bath, CA staining was excluded from the microplicae and apical subplasmalemmal region of most MP cells, whereas microplicae varied from extensive to reduced, and subapical vesicle density remained elevated. MV cells were characterized by basolateral staining with sparing of the MV and apical subplasmalemmal region in all settings except 1) after 5% CO2 and 2) when MV cells were found in areas in which MP cells were stained to the lumen. These results indicate that CA is active at the site of H+ secretion in MP cells and is correlated with the acute acid-base status of the bladder.

HCO3- secretion in mitochondria-rich cells is linked to an H+-ATPase.

Turtle bladder mitochondria-rich (MR) cells secrete H+ by an ATP-dependent process. MR cells also secrete HCO3- by an energy-requiring, Cl- -dependent process that may depend on a serosal H+-ATPase. To determine whether HCO3- is linked to an H+-ATPase, O2 consumption was assessed in MR and granular (G) cells exposed to H+ and HCO3- transport inhibitors alone and also with an H+-ATPase inhibitor. MR and G cells were separated by Ficoll density-gradient centrifugation and treated with ouabain and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) to maximally inhibit Na+ and luminal H+ transport. O2 consumption was measured before and after cells were additionally treated with 10 microM N-ethylmaleimide (NEM), an inhibitor of nonmitochondrial H+-ATPase. O2 consumption of MR cells fell after treatment with NEM (delta = 8.64 +/- 2.35 microliters O2.h-1.mg protein-1, P less than 0.025, n = 5). There was no significant difference in G cells similarly treated (delta = 1.61 +/- 0.62 microliters O2.h-1.mg protein-1, P greater than 0.05, n = 5). Because luminal H+ secretion is nearly abolished after treatment with SITS, the decline in O2 consumption of 44.4 +/- 7.11% after addition of NEM is probably due to inhibition of other non-mitochondrial H+-ATPases. In the intact bladder, HCO3- secretion was reduced by 35.1% after serosal application of NEM. Furthermore, in SITS-treated MR and G cells, ATP levels as measured by the luciferin-luciferase assay method were not appreciably different in the presence or absence of NEM.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic analysis of IDDM: the GAW5 multiplex family dataset.

In a collaborative effort by 12 centers from Europe and North America, data were assembled from 94 multiplex families with insulin-dependent diabetes mellitus (IDDM) for analysis of genetic and other factors of possible etiological importance. The dataset contains information on the following genetic markers: HLA-DR beta and -DQ beta restriction fragment length polymorphisms (RFLPs), three RFLPs detected with two probes that map 5' to the insulin gene, the serologically defined HLA loci, and the immunoglobulin allotypes. Data also were included for auto-antibodies to insulin and pancreatic islet cells as possible indicators of pathogenesis and for antibodies to certain viruses that have been implicated as "triggering" agents in IDDM. Medical history of family members was obtained by means of a uniform questionnaire. Identical copies of the dataset were distributed to anyone wishing to participate in the analysis for the IDDM component of GAW5. The multiplex IDDM family dataset is now available on request for further analysis.

Establishing the diagnosis of benign familial hematuria. The importance of examining the urine sediment of family members.

Patients with microscopic hematuria are generally referred for urologic investigation. We describe 30 patients with normal renal function referred to our clinic during the years 1970 through 1987 for evaluation of hematuria, usually microscopic, in whom prior urologic and radiological studies had failed to determine the cause of bleeding. Urinary sediment from the patients and first-degree relatives revealed hemoglobin and red blood cell casts; the inheritance pattern was consistent with autosomal dominant transmission. During follow-up for up to 18 years, renal function remained normal, thus confirming the diagnosis of benign familial hematuria. Immunoglobulin A nephropathy and Alport's syndrome were less common than benign familial hematuria and could be differentiated from it by history, physical examination, and routine laboratory testing. Since benign familial hematuria is a common disorder in adults with hematuria and normal renal function, urinary sediment from patients and family members should be examined before extensive urologic and radiological procedures are performed.

Identification of the bicarbonate secretory cell of the turtle bladder.

The turtle bladder consists primarily of two mucosal cell types, mitochondrial rich (MR) and granular (G) cells. The MR cells secrete H+. In addition, the bladder secretes HCO3-, an energy-requiring Cl(-)-dependent transport system. These studies were designed to identify the cell type responsible for HCO3- secretion. Specific HCO3- and H+ secretory inhibitors were added to alter O2 consumption of MR and G cells. Cells were separated by Ficoll density centrifugation. Ouabain (10(-4) M) was used in all studies to eliminate O2 consumption associated with Na+ transport. O2 consumption of cells treated with 10(-4) M 4-acetamido-4'-isothiocyanostilbene-2,2'-sulfonic acid (SITS), which indirectly inhibits H+ secretion, was compared with cells additionally treated with 5 X 10(-4) M acetazolamide, an inhibitor of both H+ and HCO3- secretion. O2 consumption of MR cells treated with SITS alone was significantly greater than that of MR cells additionally treated with acetazolamide (delta = 0.56 +/- 0.10 microliter O2 X h-1 X mg protein-1, n = 6, P less than 0.003). There was no significant difference in G cells similarly treated. Another means of selectively altering H+ and HCO3- transports and their associated metabolic rates is to manipulate the Cl- concentration of the incubation medium. In a Cl(-)-rich medium, HCO3- and H+ transports are maximized. In low Cl(-)-SO2-4 medium, HCO3- secretion is selectively reduced.(ABSTRACT TRUNCATED AT 250 WORDS)