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P Lang

Publications and source records attributed to P Lang.

At least 217 records · Page 12Linked to original sources
PubMed1993

Acute liver rejection: evaluation with cell-directed MR contrast agents in a rat transplantation model.

Enhancement patterns with gadolinium (4s)-4-(4-ethoxybenzyl)-3,6,9-tris (carboxylatomethyl)-3,6,9-triazaundecandioic acid (EOB) diethylenetriaminepentaacetic acid (DTPA), a hepatocyte-directed magnetic resonance (MR) contrast agent, and superparamagnetic iron oxide particles (SPIO), a Kupffer cell-directed contrast agent, were compared at MR imaging in rat models of allogeneic and syngeneic liver transplantation. Light and electron microscopy were performed to monitor the morphologic changes in these livers and revealed typical findings in acute rejecting liver (allogeneic transplants) and normal architecture in syngeneic transplants. Liver enhancement with Gd-EOB-DTPA at MR imaging was delayed and prolonged with transplantation, and even more with rejection, but the level of enhancement when compared with that of control rats remained unaffected. Uptake of SPIO was decreased in the acutely rejecting livers but was normal in the syngeneic transplantation model. Enhanced MR imaging with cell-directed contrast agents depicted decreased phagocytotic activity in acute transplant rejection and enabled the excretory function of hepatocytes to be monitored. Additionally, Gd-EOB-DTPA may be applied advantageously for detection of focal lesions in transplanted livers.

Acute Disease↗
PubMed1993

Two segments of the supraspinous muscle: cause of high signal intensity at MR imaging?

A zone of increased signal intensity seen in asymptomatic subjects near the insertion of the supraspinous tendon onto the greater tuberosity ("pseudogap") leads to difficulty in the interpretation of magnetic resonance (MR) images of the shoulder. To better understand this pseudogap, the authors dissected and sectioned the shoulders of four cadavers and analyzed 20 MR images of patients' shoulders. They found that the supraspinous muscle consists of two distinct portions: an anterior fusiform portion that contains the dominant tendon and a straplike posterior portion. The orientation of the dominant tendon differs from that of the main muscle by approximately 10 degrees. In addition, oblique-coronal MR images were obtained parallel to the supraspinous main muscle and the central tendon in six volunteers; the appearance of the pseudogap was similar with both projections. Fat-saturated and gradient-echo images of the shoulder were obtained with increasing echo times in four additional volunteers. There was no evidence of fat within the pseudogap. Because the anatomic composition of the pseudogap could not be explained with partial volume averaging with adjacent muscle or fat, the authors conclude that it may represent a manifestation of unique focal tissue relaxation parameters or depend on the tendon orientation in the main magnetic field.

Adult↗
PubMed1993

Mucosal immunity in primary glomerulonephritis. III. Study of intestinal permeability.

To study the specificity of gut hyperpermeability in primary glomerulonephritis, we investigated intestinal permeability by means of 51Cr-EDTA testing in 20 healthy individuals and in 30 patients with Immunoglobulin A nephropathy (IgA GN), 25 with idiopathic nephrotic syndrome (INS) and 20 with immune complex glomerulonephritis (IC-GN; membranous+membranoproliferative glomerulonephritis). Gut permeability was statistically increased in each patient group versus the controls [controls: 2% (0.4-3.9); IgA GN: 3.25% (0.7-17.70); INS: 3.71% (0.82-10); IC-GN: 3.40% (0.30-16); results are median (range); p < 0.005, nonparametric Mann-Whitney test]. An increase in intestinal permeability exceeding the upper limit of control values (95th percentile) was observed in 36% of IgA GN, 60% of INS and 50% of IC-GN patients. We conclude that intestinal permeability is frequently increased in primary glomerulonephritis and may also be increased in types of glomerulonephritis other than IgA GN.

Adult↗
PubMed1993

Long-term cyclosporin A therapy for severe idiopathic membranous nephropathy.

Fifteen patients with nephrotic idiopathic membranous nephropathy (MN) with predictors of poor outcome were treated with a long cyclosporin A (CyA) regimen at the dose of 4-5 mg/kg/day for a median period of 15 months (range 12-30). Four of the 15 patients did not respond to CyA, and the therapy was discontinued after 4 months. A partial remission (proteinuria < 2 g/day) was observed in 7 of 15 patients and a complete remission (proteinuria < 0.2 g/day) in 4 of 15 patients; good results (partial+complete remission) were, thus, obtained in 11 of 15 patients (73%). Two patients are still receiving therapy. A relapse of the nephrotic syndrome occurred in 3 of 9 patients on withdrawal of CyA, but the relapse remained sensitive to CyA. Side effects were mild. We conclude that CyA may be efficient in the treatment of MN and should be evaluated in controlled trials.

Adult↗
PubMed1993

Inhaled nitric oxide in congenital heart disease.

BACKGROUND: Congenital heart lesions may be complicated by pulmonary arterial smooth muscle hyperplasia, hypertrophy, and hypertension. We assessed whether inhaling low levels of nitric oxide (NO), an endothelium-derived relaxing factor, would produce selective pulmonary vasodilation in pediatric patients with congenital heart disease and pulmonary hypertension. We also compared the pulmonary vasodilator potencies of inhaled NO and oxygen in these patients. METHODS AND RESULTS: In 10 sequentially presenting, spontaneously breathing patients, we determined whether inhaling 20-80 ppm by volume of NO at inspired oxygen concentrations (FIO2) of 0.21-0.3 and 0.9 would reduce the pulmonary vascular resistance index (Rp). We then compared breathing oxygen with inhaling NO. Inhaling 80 ppm NO at FIO2 0.21-0.3 reduced mean pulmonary artery pressure from 48 +/- 19 to 40 +/- 14 mm Hg and Rp from 658 +/- 421 to 491 +/- 417 dyne.sec.cm-5.m-2 (mean +/- SD, both p < 0.05). Increasing the FIO2 to 0.9 without adding NO did not reduce mean pulmonary artery pressure but reduced Rp and increased the ratio of pulmonary to systemic blood flow (Qp/Qs), primarily by increasing Qp (p < 0.05). Breathing 80 ppm NO at FIO2 0.9 reduced mean pulmonary artery pressure and Rp to the lowest levels and increased Qp and Qp/Qs (all p < 0.05). While breathing at FIO2 0.9, inhalation of 40 ppm NO reduced Rp (p < 0.05); the maximum reduction of Rp occurred while breathing 80 ppm NO. Inhaling 80 ppm NO at FIO2 0.21-0.9 did not alter mean aortic pressure or systemic vascular resistance. Methemoglobin levels were unchanged by breathing up to 80 ppm NO for 30 minutes. CONCLUSIONS: Inhaled NO is a potent and selective pulmonary vasodilator in pediatric patients with congenital heart disease complicated by pulmonary artery hypertension. Inhaling low levels of NO may provide an important and safe means for evaluating the pulmonary vasodilatory capacity of patients with congenital heart disease without producing systemic vasodilation.

Administration, Inhalation↗
PubMed1993

Investigations of the architecture of tamarind seed polysaccharide in aqueous solution by different scattering techniques.

The architecture of tamarind seed polysaccharide (TSP) has been investigated by light scattering (LS), small angle X-ray scattering (SAXS) and synchrotron radiation scattering (SRSAXS). The experimental data show that TSP in aqueous solution consists of multi stranded aggregates, with a high degree of particle stiffness. The angular dependence of the scattered intensity is typical for wormlike chains. Data evaluation on the basis of this model yields a statistical Kuhn segment length lK = 150 nm. The cross sectional radius of gyration is estimated as Rgcs = 6.0 +/- 0.5 A, which is more than twice the value, published for single stranded polysaccharides. Correspondingly, the experimental value of the linear mass density, measured by LS, is about five times higher than the theoretical value calculated from the primary structure.

Light↗
PubMed1993

Antigen binding and effector functions of a chimeric antibody with a deletion of the CH1 domain and non-covalently associated kappa chains.

In a mouse/human chimeric IgG1 Ab with a deletion of the CH1 domain the disulfide bridges between H and L chain cannot be formed, although the corresponding cysteine residues are present. We show that the kappa chains are non-covalently associated to H chain dimers and that they can dissociate from the H chains. Therefore different populations of Ab can be distinguished according to the number of associated kappa chains. Only the molecules with two kappa chains can bind to the target cell. Since this Ab was derived from a T cell depleting anti-Thy-1.2 Ab, we can assess the implications of this conformational alteration as to binding avidity, effector functions and immunosuppression in vivo.

Animals↗
PubMed1993

Acute fracture of the femoral neck: assessment of femoral head perfusion with gadopentetate dimeglumine-enhanced MR imaging.

OBJECTIVE: Evaluation of the perfusion and viability of the femoral head after fracture of the femoral neck is important because the outcome of conservative treatment or joint-preserving surgery is adversely affected by the development of capital osteonecrosis. We evaluated the use of MR imaging, before and after IV administration of gadopentetate dimeglumine, for assessing perfusion of the femoral head in 13 patients with acute fracture of the femoral neck. SUBJECTS AND METHODS: Multiecho (1600/30-240 [TR/TE]) MR images were obtained before contrast administration and gradient-echo (315/14, 90 degrees flip angle) MR images were obtained both before and after contrast administration. MR findings were correlated with findings on superselective digital subtraction angiograms of the vessels supplying the femoral head and with clinical-radiographic follow-up for at least 12 months. RESULTS: Digital subtraction angiography showed impaired blood supply to the femoral head in five patients. On contrast-enhanced MR images of these patients, the femoral head did not enhance and was lower in signal intensity than were the enhancing femoral shaft and neck distal to the fracture and the enhancing femoral head on the unaffected side. In the patients with persistent perfusion, contrast-enhanced MR images showed a uniform increase in signal intensity in the femoral shaft and neck as well as the femoral head; the femoral head on the fractured side showed contrast enhancement similar to that on the healthy side. CONCLUSION: These preliminary results indicate that contrast-enhanced MR imaging may be useful for noninvasive evaluation of femoral head perfusion after fracture of the femoral neck. MR findings also may aid the clinician in deciding between joint-preserving therapy and hip arthroplasty.

Acute Disease↗
PubMed1993

A CD2+ subset of non-malignant peripheral blood lymphocytes from patients with Sézary syndromes overexpress the low-molecular-weight GTP-binding protein Rab2.

The Rab branch of the Ras-related GTP/GDP-binding proteins currently includes at least 25 related members which are involved in the intracellular vesicular transport along the secretory and endocytic pathways in eukaryotic cells. The overexpression of the Rab2 protein in peripheral mononuclear cells is demonstrated from 13 out of 17 patients exhibiting a Sézary syndrome. Moreover, this phenomenon is detectable in other lymphoid and myeloid malignancies. Several lines of evidence are shown suggesting that the Rab2 overexpression can be related not to leukemic cells but to a subset of peripheral lymphocytes with a CD2+ phenotype. Our results provides strong evidence for the implication of a small GDP/GTP-binding protein in immunological events associated with neoplastic states. The precise cellular population involved in this process remains to be determined.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1993

[A newly developed cementless elbow joint prosthesis].

Authors describe briefly the history of the development of elbow arthroplasty. They report on their experiences with the silicone, cementless, unconstrained elbow prosthesis developed by them and implanted in 23 cases during 3 years. The prosthesis is described, the operative indication and the problems of the operative technique are reviewed. On the basis of their results and the low number of complications this method of operation is suggested first of all for the successful treatment of elbows with rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1993

Effect of prophylactic ganciclovir on cytomegalovirus infection in renal transplant recipients.

Cytomegalovirus (CMV) infection is the most frequent infectious complication observed in renal-transplant recipients and induces a significant morbidity in these patients due to CMV disease itself and to associated renal dysfunction or opportunistic superinfection. In order to evaluate the effect of gangiclovir prophylaxis we conducted an open-label prospective randomized study of ganciclovir administration in CMV seronegative recipients of a renal allograft from CMV seropositive donors. Ganciclovir (5 mg/kg b.i.d./day for 14 days) was started on day 14 after transplantation. Thirty-two patients were included in this study (15 in the control group, 17 in the ganciclovir group). There was no significant difference between the two groups for age, immunosuppressive regimen, number of rejection, steroid pulses, and OKT3 treatments. Renal and patient outcomes were similar in both groups. The rate of CMV infection and CMV disease were similar in both groups (80% and 73.3% in the control group versus 70.6% and 47.1% in the ganciclovir group; P = NS). Less severe CMV disease was observed in the ganciclovir group compared to controls. The delay between transplantation and CMV infection was significantly longer in the ganciclovir group compared to control group (68.1 +/- 5.1 versus 44.0 +/- 5.2 days, P < 0.005). Twelve group patients (80%) versus nine (53%) of the ganciclovir group required curative treatment with ganciclovir after the diagnosis of CMV infection (NS). All the patients recovered from CMV disease and no significant side effect was observed during ganciclovir administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Simultaneous heart and kidney transplantation using the same donor].

From 1988 to 1991, five cases of combined heart and kidney transplantation using the same donor have been achieved at our institution. All patients were males, 58 +/- 6 (46 to 64). The cardiac condition leading to the cardiac replacement was a dilated cardiomyopathy in one case, end-stage ischemic disease in 3, and failure of a previous cardiac transplantation in one. The renal condition claiming for a graft was a Glomerular nephritis in one, a polycystic disease in 3, and renal failure due to CyA toxicity in one; chronic hemodialysis was mandatory in all patients but one. There were no hospital deaths. The five patients are current survivors, the mean follow-up being 22 +/- 10 months (2-50 months). Five rejection episodes occurred in three patients; two patients have never demonstrated any cardiac rejection. All but one recovered a normal renal function as soon as the 7 th post operative day; only one episode of renal rejection has been detected, easily reversed by corticoids. No simultaneity was ever observed between cardiac and renal rejection episodes. Thus, the detection of rejection must be carried out separately for each graft organ. In four patients, cineangiograms of the coronary vessels were done respectively 12, 30 and 50 months post operatively and revealed a normal coronary bed. Thus, combined heart and kidney transplantation seems to be a realistic approach in properly selected patients in whom cardiac and renal failures cannot be treated by more conventional procedures.

Heart Transplantation↗
PubMed1993

Radiologic diagnosis of osteoporosis. Current methods and perspectives.

Osteoporosis is defined as a decrease in bone mass accompanied by structural changes, leading to an increase in fracture propensity. Early diagnosis of osteoporosis, fracture risk prediction, and assessment of efficacy of therapy therefore are of great interest. A number of noninvasive techniques are available for measuring bone mass at multiple sites of the skeleton. This article reviews basic methodology and developments in radiology such as x-ray and photon absorptiometry and quantitative computed tomography, which are routinely used in clinical practice. Recent techniques for assessment of bone mineral density and structure, such as ultrasound measurements, and their possible clinical applications also are discussed.

Absorptiometry, Photon↗