Successive infection of coxsackievirus B3 and encephalomyocarditis virus: an animal model of chronic myocarditis.

Successive infection of coxsackievirus B3 and encephalomyocarditis virus was investigated as a disease model of chronic myocarditis. Four-week-old C3H/He mice were inoculated with coxsackievirus B3 and then inoculated with encephalomyocarditis virus at 8 weeks old. The hearts were evaluated on histopathological changes compared with those of non-infected mice and mice infected with either virus alone. At 10 weeks old, the hearts of the mice infected successively with both viruses showed co-existence of fibrosis surrounding calcified lesions and marked cellular infiltration with myocardial necrosis. These findings resembled chronic active myocarditis in humans, unlike the lesions due to either virus alone. At 12 weeks old, the hearts of all the infected mice showed fibrosis with scarce cellular infiltration. The successively infected hearts also showed a significantly higher heart weight to body weight ratio than that of the non-infected control mice, and localized wall thinning in the damaged regions. Thus, we conclude that successive infection additively causes myocardial damage that resembles chronic myocarditis and may produce a heart condition similar to dilated cardiomyopathy.     

Flexible printed-circuit probe for electrophysiology

Photofabrication techniques have been used to produce a nickel-iron microelectrode array on Kapton film specifically designed for biological implantation. The probe is 2·5 mm×2 mm and carries four tissue terminals, each 2 μm in width. Both spontaneous and evoked potentials have been recorded from frog sciatic nerve. Developmental possibilities for the probe are fully discussed.     

Reproducibility of the parameters of the on-transient cardiopulmonary responses during moderate exercise in patients with chronic obstructive pulmonary disease

To be clinically useful as indices reflective of altered physiological function consequent to interventions in patients with chronic obstructive pulmonary disease (COPD), the time constant (τ) and steady-state amplitude of the kinetic responses for oxygen uptake ( ) carbon dioxide output ( ) ventilation ( ) and heart rate (HR) have to be appropriately differentiable and reproducible. We therefore assessed the reproducibility of τ and steady state amplitude values in 41 patients with severe COPD [mean (SD)] [forced expiratory volume in 1 s=41 (7)% predicted], aged 64 (5) years. Of the total, 6 of the patients (15%) did not produce breath-by-breath data of sufficient quality to warrant kinetic analysis. The remaining 35 patients completed two moderate-intensity 10 min square-wave exercise tests separated by 2 h, both before and after an endurance training programme. Tests were conducted on an electromagnetically-braked cycle ergometer at an exercise intensity corresponding to 80% of the estimated lactate threshold (θ_La) or 50% of peak oxygen uptake if θ_La was insufficiently differentiable. Breath-by-breath measurements of , , and HR were averaged into 10 s bins and the on-transient response kinetics were estimated using a mono-exponential model. Analysing the pre-training and the post-training test 1 and test 2 comparisons together, the test 1 –test 2 differences were not significantly different from 0 for either τ or A. The standard deviation of the test 1 –test 2 differences allowed us to define the magnitude of change that would reach statistical significance. For τ, this averaged some 8, 10, 11 and 8 s, for , , and HR, respectively, for a one-tailed paired-comparisons test (i.e. appropriate for assessing hypothesised improvements resulting from an intervention); for a two-tailed comparison, the differences were approximately 2 s greater. The corresponding one-tailed values for A were 100 ml·min^–1, 95 ml·min^–1, 2.5 1·min^–1 and 4 beats·min^–1, respectively; the two-tailed values were 10%–15% greater. We therefore conclude that both τ and A for moderate-intensity exercise can be reproducibly estimated in patients with COPD when the data set provides a sufficiently large amplitude of response and sufficiently low sample variability to allow appropriate parameter estimation. Electronic Publication     

The nephronophthisis complex

Summary The clinical and morphological findings are described in 27 children with nephronophthisis. Seventeen children were considered as sporadic cases. In 10 familial cases the presumed mode of inheritance was autosomal recessive. The clinical picture was rather uniform: polyuria-polydipsia, hyposthenuria, anemia, growth retardation, and azotemia with progressive renal failure. Six patients presented with tapeto-retinal degeneration. In a further seven children other ocular changes were detected. Two female siblings showed additional non-renal manifestations: mental retardation, pulmonary emphysema, skeletal anomalies, and congenital hepatic fibrosis.Renal histology displayed a chronic sclerosing tubulo-interstitial nephropathy with extensive tubular atrophy and dedifferentiation. Medullary cysts were frequently found in end-stage kidneys. Immunofluorescence was either non-specific or completely negative. On electron microscopy, the tubular basement membrane changes predominated: thickening, lamellation, splitting, and deposition of microfibrils within the increased basement membrane substance. Detailed light- and electron microscopic findings were non-specific but the overall morphologic picture was characteristic and even diagnostic in conjunction with the clinical presentation.A recurrence of nephronophthisis in transplanted kidneys has not been observed.The pathogenesis of nephronophthisis is obscure but with respect to the morphologic findings a primary or secondary tubular basement membrane defect seems very likely.Our experience suggests that nephronophthisis is a frequent cause of chronic renal failure in children and commonly associated with non-renal abnormalities. To avoid the separation of different syndromes presenting with a uniform renal disease but various non-renal manifestations, we suggest that the term nephronopthisis complex be used.Presented in part at the 63th Annual Meeting of the German Society of Pathology, Stuttgart 1979     

B-cell function in patients with chronic lymphocytic leukemia

Summary Using a reverse hemolytic protein A plaque assay, spontaneous and pokeweed mitogen (PWM)-induced immunoglobulin (Ig) secretion was determined in peripheral blood from 22 patients with B₁-chronic lymphocytic leukemia (CLL), one patient with B₂-CLL, and one patient with suppressor T-CLL. Diagnoses were established by cytological and histological criteria as well as several marker analyses. Lymphocytes from B₁- and B₂-CLL patients were unable to secrete Ig either spontaneously or after PWM stimulation. In T-CLL lymphocytes, spontaneous Ig secretion was suppressed very probably by the OKT-8-positive leukemic population, since, after cultivation with PWM, a normal Ig secretion could be demonstrated which was paralleled by a decrease in the OKT-8-positive cells. Cocultivation experiments with freshly isolated, unseparated lymphocytes from normal subjects and lymphocytes from patients were of no informational value, since isolated normal B-cells alone already showed a high rate of Ig secretion. However, coculture experiments with separated subpopulations after PWM stimulation revealed an intrinsic B-cell defect in lymphocytes from B₁-CLL patients, whereas their T-lymphocytes were found to be normal helper cells.

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Abbreviations CLL Chronic lymphocytic leukemia - PWM Pokeweed mitogen - ISC Immunoglobulin-secreting cells - Ig Immunoglobulin(s) Supported by the Deutsche Forschungsgemeinschaft (Ru 215/2)     

Structural and functional complexity of the humoral response against the Trypanosoma cruzi ribosomal P2 beta protein in patients with chronic Chagas' heart disease

High levels of antibodies against the C-terminus of the Trypanosoma cruzi TcP2 beta ribosomal protein, defined by the peptide EEEDDDMGFGLFD, named R13, have been measured in sera from patients with chronic Chagas' Heart Disease (cChHD). These antibodies also recognize an epitope on the second extracellular loop of the beta 1-adrenergic receptor, inducing a functional response on cardiomyocytes. The aim of this study was to gain novel insights into the structural basis of this cross-reactivity as well as to evaluate the origin of anti-M2- cholinergic receptor antibodies, which are also commonly found in cChHD patients. To address these questions we immunopurified anti-R13 antibodies and studied the structural requirements of epitope recognition. Results showed that the immunopurified antibodies recognized a conformation of R13 in which the third Glu residue was essential for binding, explaining their low affinity for the mammalian homologue (peptide H13: EESDDDMGFGLFD). Alanine mutation scanning showed individual variations in epitope recognition in each of the studied patients. The importance of a negatively charged residue at position 3 for the recognition of anti-R13 antibodies was further confirmed by competition experiments using a Ser3-phosphorylated H13 analogue, which had 10 times more affinity for the anti-R13 antibody than the native H13 peptide. Moreover, anti-R13 antibodies stimulated either the beta 1-adrenergic or the M2-cholinergic receptor, in strict agreement with the functional properties of the IgG fractions from which they derived, demonstrating that the same parasite antigen may generate antibody specificities with different functional properties. This may be a clue to explain the high variability of electrophysiological disturbances found in cChHD.     

Microangiopathy in human diabetic neuropathy

Summary Morphological change of endoneurial and perineurial vessels accompanied severe loss of myelinated axons in peripheral nerves of each of 17 patients with diabetic neuropathy. Vascular mural thickening averaged 18.9±9.9 m² in diabetic capillaries (n=11) vs. 6.9±4.1 m² in controls (n=7). Electron microscopy revealed vigorous endothelial proliferation as well as thickening and reduplication of basal lamina in each instance. Particular attention was paid to vessels which penetrate the perineurium en route to the endoneurial intertitium, since they provide a major portion of the endoneurial blood supply. Luminal narrowing and mural thickening of these vessels was compounded by basal laminar thickening of the perineurium. Fenestrated endoneurial capillary endothelium was noted in one case. Both demyelination and axonal degeneration were observed with intra-axonal glycogen accumulation in some axons. Morphometric analysis revealed extensive myelinated nerve fiber loss in diabetic nerves. These morphological findings emphasize the impact of diabetic microangiopathy on specialized endothelium and suggest that local anatomic factors in the perineurial sheath render the nerve vulnerable to chronic ischemia.Supported in part by the National Institute for Communicative Disorders and Stroke NS-14162 and by the Veterans Administration Research Service     

Chronic neurogenic quadriceps amyotrophies

Summary Two cases of quadriceps amyotrophy, probably of chronic neurogenic origin are reported. Only the knee jerks were diminished, the calves hypertrophic, and the serum creatine kinase level very high in one case, and there were neurogenic electromyographic abnormalities in the quadriceps. In the first case, biopsy of the quadriceps muscle revealed a neurogenic origin with hyalinized hypertrophic fibres. CT scan showed abnormalities not only in the quadriceps but also in the sartorius, gracilis and gastrocnemius muscles. A second biopsy specimen from the gastrocnemius muscle showed histological findings similar to those of the quadriceps. In the second case, the EMG and biopsy findings suggested a myogenic origin, but 6 years later they were compatible with neurogenic atrophy. Differentiation from Becker dystrophy is very difficult in the first case and the second case is more a focal spinal amyotrophy. Further, in spite of their localization, the extension of the affected muscles changes the diagnosis. The same applies to chronic quadriceps amyotrophy in general, which cannot be regarded as an entity, but which suggests muscular dystrophy, spinal atrophy, polymyositis or a metabolic disorder. These cases can be compared with the four cases reported in the literature, which were regarded as a forme fruste of chronic spinal amyotrophy.     

Human cognitive function following binedaline (50 mg and 100 mg) and imipramine (75 mg): Results with a new battery on tests

Rats were made diazepam dependent by chronic treatment with daily injections of the drug, 20 mg/kg, IP, for 3 weeks. On abrupt termination of the drug, the animals showed withdrawal hyperactivity which was indicated by increased horizontal locomotion and vertical activity, and diarrhoea. The peak effect was seen 3 days after the withdrawal of diazepam. Effects of various alpha₂ agonists, clonidine, guanfacine and B-HT 920, were studied on the diazepam withdrawal phenomena. Clonidine (100 g/kg, IP) given twice a day at an interval of 12 h prevented both withdrawal-induced hyperactivity and diarrhoea. On the contrary, equimolar doses of guanfacine and B-HT 920 failed to reverse withdrawal-induced hyperactivity but attenuated the effect of diarrhoea. However, higher doses (500 g/kg, IP) of guanfacine and B-HT 920 given twice a day at 12-h intervals were found to be effective. Pretreatment with yohimbine (1.5 mg/kg, IP) reversed the protective effect of clonidine, indicating the involvement of alpha₂ receptors in the action of clonidine.