Factors predisposing to post-renal transplant erythrocytosis. A prospective matched-pair control study

We conducted a prospective study on 81 consecutive patients who had a kidney transplant with graft function for over 3 months to evaluate the prevalence of erythrocytosis following renal transplantation (PTE) and its potential risk factors. True PTE was defined as a RBC mass > 120% of the theoretical value allowing for sex, weight and height. 18 patients (22.2%) developed PTE (RBC mass = 157 +/- 21%) with no evidence of polycythemia vera (PV), or secondary polycythemia due to reduced arterial oxygen, kidney or hepatic tumors. PTE was more common in males (p = 0.041) and less common in patients treated with recombinant erythropoietin (rHEPO) prior to transplantation. 18 non-polycythemic patients (Hb 12.6 +/- 1.3 g/dl) matched for sex, age and renal function were used as case controls. Fewer PTE patients were transfused post-transplantation (p = 0.026). At the time of diagnosis, mean serum EPO was normal and similar to that of controls. PTE patients had lower serum ferritin (p = 0.005) and more commonly received iron supplementation when PTE occurred (p = 0.003). Other clinical factors did not differ significantly between the two groups. Two patients had a thrombotic event, 6 recovered spontaneously and 11 were successfully treated with angiotensin-converting enzyme inhibitors (ACEI). The normalization of Hb, hematocrit and RBC mass in ACEI treated patients was accompanied by a decline in serum EPO (p = 0.008). We conclude that true erythrocytosis is prevalent in cyclosporine-treated renal transplant patients. PTE seems to be an idiopathic erythrocytosis. Pretransplant rHEPO treatment may limit PTE by blunting the increased sensitivity of erythroid precursors to EPO and iron supplementation, which stimulates the development of PTE. ACEI treatment is effective and safe.

Effect of cyclothiazide on binding properties of AMPA-type glutamate receptors: lack of competition between cyclothiazide and GYKI 52466

The effects of cyclothiazide on the properties of (R,S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors were studied using equilibrium binding techniques and interactions with other compounds known to modulate the receptors. Cyclothiazide caused a reduction in [3H]AMPA binding in assays carried out in the presence of thiocyanate, a chaotropic ion that markedly increases the affinity of AMPA receptors and accelerates their desensitization. In the absence of thiocyanate, however, cyclothiazide had no reliable effect on the binding of [3H]AMPA or on the affinity for this agonist assessed from the displacement of [3H]CNQX. The interaction of cyclothiazide with the receptor appears not to be changed by the presence of thiocyanate. Analysis of the results with a kinetic model of the AMPA receptor suggests that cyclothiazide does not block receptor desensitization by making the desensitized state inaccessible but rather by stabilizing the active state, i.e., by increasing the affinity of the latter to a point where it becomes energetically more favorable than the desensitized state. GYKI 52466, an atypical benzodiazepine that blocks AMPA receptor-gated currents, did not reverse the changes in binding affinity produced by cyclothiazide in the presence of thiocyanate. Physiological experiments conducted in excised patches collected from hippocampal pyramidal cells indicated that thiocyanate does not block access of GYKI 52466 to AMPA receptors. These results point to the conclusion that cyclothiazide acts at a site on the AMPA receptor different from that for GYKI 52466.

Hepatitis C after renal transplantation: histopathological correlations

This study evaluates the correlations between liver histology, cytolysis, cryoglobulinaemia, co-infection with hepatitis B virus, and immunosuppressive treatment in renal transplant patients with HCV infection. Forty-five of 378 kidney recipients (January 1973-September 1993) had anti-HCV antibodies (prevalence = 11.9%) detected by second generation ELISA (Abbott Pasteur). Viral RNA was detected in those patients by RT-PCR in serum and liver. HCV-positive patients underwent liver biopsy to assess their liver tissue lesions according to Knodell's score. Patients were also screened for Hbs, Hbc and Hbe antigens (ELISA, Abbott) and cryoglobulins (immunobinding, SEBIA). Of the 45 HCV+ patients, 38 (84.4%) had persistent viral replication in the serum and 29 of the 30 patients having undergone liver biopsy had PCR-positive liver tissue. The liver biopsies revealed no active hepatitis lesion in 14 patients (46.6%, Group CAH-), 16 (53.3%) had chronic active hepatitis (Group CAH+) and 3 (10%) had signs of cirrhosis. Comparing groups CH+ and CH- showed that viral replication was detected in all 16 patients with chronic active hepatitis, versus 10/14 patients in the CAH- group (P < 0.05). Patients were more frequently treated with azathioprine in the CH+ group (12/16 vs 8/14; P < 0.05). The duration of renal transplantation was significantly longer in patients with a Knodell score > 5 (58 +/- 56 months vs 35 +/- 29 months, P < 0.001). Incidence of co-infection with HBV was similar in both groups. The mean values of alanine aminotransferase correlated with the Knodell score (r = 0.4, P = 0.03). Mixed cryoglobulinaemia was more common in the replicant forms of HVC infection (12/38 vs 1/7, P < 0.0001). This study shows that liver histological lesions are correlated with HCV viral replication, are more frequent in patients treated with azathioprine and are more severe as the duration of transplant is longer.

[Diagnosis of tumors by needle aspiration cytology]

Fine needle aspiration cytology is considered an adequate method fulfilling the requirements for an early, minimal invasive, and simple to perform diagnostic technique for malignancies. Its establishment in human medicine is the basis for propagation of this method in veterinary medicine. This paper describes the technique of performing a fine needle aspiration and gives guidelines for the interpretation of cytologic samples. Indications, limitations and contraindications of aspiration cytology are discussed.

[Ki-1 positive non-Hodgkin's lymphoma disclosed by mucocutaneous ulcerations and glomerulonephritis]

Malignant lymphoma particularly of T phenotype can be associated with specific or non specific cutaneous lesions. These cutaneous manifestations can occur at the onset of the disease being sometimes the revealing sign or they can appear during the course of the lymphoreticular malignancies. Glomerulonephritis was also described in lymphoma. Ki-1 positive large cell lymphoma was recently identified. A new case is reported with lymphadenopathy and intestinal localisation revealed by cutaneous and mucosal ulcerations principally in the mouth and a focal segmental glomerulonephritis with endo- and extracapillary proliferation. The absence of lymphoma in cutaneous and renal lesions and the clinical presentation support the hypothesis of paraneoplastic manifestations, may be related to a vasculitis.

[Imaging methods in diagnosis and differential diagnosis of breast cancer]

The diagnosis of breast cancer is primarily based on X-ray mammography. Under optimal conditions, a sensitivity of approximately 90% can be achieved. When strict criteria of indication are observed for the additional use of ultrasound or contrast-enhanced MRI, the sensitivity can be increased to about 98%. In addition, the differential diagnosis between benign and malignant lesions can be improved and the rate of biopsies due to false-positive mammograms can be reduced. However, further investigation with ultrasound or MRI of dense or mastopathic breasts that are clinically asymptomatic is not indicated, since it reduces specificity without significant gain of sensitivity.

Epstein-Barr virus lymphoproliferative disease of donor origin after kidney transplantation: a case report

A case of an Epstein-Barr virus (EBV)-associated B lymphoproliferative disorder presented as a renal transplant obstruction is reported. The diagnosis was made from histology, immunohistochemistry, and EBV expression studies. Cytogenetic analysis showed the tumor to be of donor origin and revealed chromosomal translocation 46, XY, inv (1)(p35; q41), involving the EBV insertion site 1(1p35) and transforming growth factor beta 2(1q41) loci.

Effect of thiocyanate on AMPA receptor mediated responses in excised patches and hippocampal slices

The binding affinity of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors for [3H]AMPA is increased 10-30-fold by the chaotropic anion thiocyanate. The present experiments tested if thiocyanate alters AMPA receptor mediated current fluxes and if any such effects are reflected in the waveform of synaptic responses. Currents were measured after a step application of glutamate or AMPA to patches excised from pyramidal cells of hippocampal slice cultures. Application of 1 mM AMPA produced responses with an average peak amplitude of 86 pA at -50 mV and a 10-90% rise time of 1.7 +/- 0.1 ms; the responses desensitized to a steady-state level below 10% of the peak current with a time constant of 11.1 +/- 0.7 ms. Glutamate in presence of D-amino-phosphonopentanoate produced similar responses which were inhibited by 6-cyano-7-nitro-quinoxaline-dione and enhanced by aniracetam or cyclothiazide and thus are characteristic for AMPA receptors. Thiocyanate accelerated the decay of AMPA responses two-fold and reduced the peak current by 30-50% with an EC50 of 3.2 mM which is comparable to its EC50 for enhancing binding. Effects on the desensitization of glutamate induced responses were much smaller and only evident at the highest thiocyanate concentration; no effect was seen on response amplitude. Binding and physiological effects can be adequately explained by assuming that thiocyanate enhances conversion from the sensitive to the desensitized state of the receptor and reduces ligand dissociation from the desensitized state. Synaptic responses were measured in disinhibited hippocampal slices. Perfusion with 20 mM sodium thiocyanate increased the slope of the field excitatory postsynaptic potential by 44.9 +/- 4.2% and reduced its decay time by 10.4 +/- 4.3%. The former effect appears to result at least in part from an increase in transmitter release since it was accompanied by a decrease in paired-pulse facilitation and was reduced in magnitude after enhancing transmitter release. The decrease in the decay time constant points to an effect of thiocyanate on AMPA receptors in situ which is similar to that seen in excised patches. These results demonstrate that an increase in binding affinity may be indicative of reduced rather than enhanced current flow through AMPA receptors. In addition, the results provide further evidence that the kinetics of the AMPA receptor channel contribute significantly to at least the decay phase of fast excitatory synaptic responses.

Serum anti-dextran antibodies in IgA nephropathy

Abnormally high humoral responses have been described in IgA nephropathy (IgAN), towards antigens commonly involved in infectious events or food intolerance. Here we report a comparative analysis of humoral responses to a common environmental antigen, dextran B 512, present both in nonpathogenic microorganisms and normal diet. Dextran-specific IgG, IgA and IgM were assayed using an ELISA method in serum samples from 121 patients with IgAN, 40 controls and 32 patients with biopsy-proven renal diseases different from IgAN. Among the latter, 17 were transplant recipients. Anti-dextran IgG antibodies were found significantly (p < 0.05) more frequently and at higher levels in IgAN patients than in patients with other renal diseases. Anti-dextran IgA were at significantly (p < 0.05) higher levels in IgAN patients than in controls or untransplanted NIgAN patients. However, similarly elevated levels of anti-dextran IgA were found in IgAN patients and transplanted patients with other renal diseases. These data confirm that IgA and IgG responses towards common antigens are elevated in IgAN, possibly as a consequence of the pathogenesis of this disease rather than because of renal impairment. Moreover, since the same degree of dysregulation was noted in the control group of transplanted patients whose initial diagnosis was not IgAN, these data favour the hypothesis of a global dysregulation of the IgA system in IgAN, yielding enhanced humoral immune responses to possible pathogens and diet antigens.

[Mast cell tumors in dogs--diagnosis and therapy of a malignant skin tumor]

The high prevalence of mast cell tumors in dogs and their variable presentation make this neoplasia a diagnostic and therapeutic challenge for the small animal practitioner. Classification of the tumor according to histologic grade and clinical stage of the disease is important for therapy and prognosis. Surgical excision and chemotherapy are discussed for individual tumor grades and stages.

Magnetic resonance imaging may be an asset to diagnose and classify fluoroquinolone-associated Achilles tendinitis

The aim of this study was to document the accuracy of magnetic resonance imaging (MRI) during fluoroquinolone-associated Achilles tendinitis. Fourteen Achilles tendons were examined by MRI (T1 and T2 or T2*-weighted sequences) in nine patients with typical tendinopathy (13 cases of tendinitis and 1 rupture) during fluoroquinolone therapy. Tendinous involvement was classified according to the prominence of intra- or peritendinous changes. The most typical feature was the presence of intratendinous changes, longitudinal or transversal, detected on T1 or T2-weighted sequences. Peritendinitis was most visible in two cases and nodular involvement in three cases. It was concluded that MRI appears a helpful and accurate method in identifying and classifying such iatrogenic tendinitis. In addition, MRI indicates orthopedic management when detecting risk of rupture.

[Diagnosis of the site and extent of breast carcinoma]

The value of X-ray-mammography, ultrasound, and MRI are compared with regard to their results in localization, differential diagnosis, and staging of carcinomas of the breast. For microcalcifications that are only imaged by mammography, X-ray is superior to the other imaging modalities and remains method of choice. Ultrasound is the most useful to differentiate cystic and solid lesions. The value of MRI is not yet proved sufficiently except in conservative and plastic surgery of breast carcinoma.