Histological studies of vascularised nerve graft and conventional nerve graft

Histological studies of vascularised nerve graft versus conventional nerve graft were performed in eighteen rat femoral nerves using microsurgical technique. This experiment showed that there was no difference in the degree of vascularisation, reticulin framework collapse, rate and extent of axonal regeneration and remyelination between the two groups.

Dystrophic and psammomatous calcifications in a desmoid tumor. A light microscopic and ultrastructural study

A desmoid tumor occurring in the abdominal wall of a 6-year-old boy with extensive microcalcifications was documented. Two forms of calcifications were observed: an irregular, amorphous dystrophic calcification of the collagen fibers and an organized, laminated psammomatous calcification (psammoma bodies). Ultrastructural studies revealed that the dystrophic calcification is a result of direct mineralization of individual collagen fibrils with subsequent coalescence to form large, calcified masses. Psammomatous calcification tended to cluster around areas where the collagen fibers assumed a whorled configuration. It is suggested that the circular orientation of the collagen fibers in some way favors the laminar deposition of hydroxyapitite crystals. The cause of the pathologic calcifications is the presence of extensive amorphous eosinophilic degeneration of the collagen fibers.

Ultrastructural observations of chronic uremic lungs with special reference to histochemical and X-ray microanalytic studies on altered alveolocapillary basement membranes

Electron microscopic observations of chronic uremic lungs were carried out in 6 uremic patients with special reference to histochemical and X-ray microanalytic studies on the altered alveolocapillary basement membranes. Epithelial damage varying from edematous swelling of the epithelial cells to total disruption and desquamation of the epithelium was often present. Although degenerative changes of capillary endothelium such as swelling and vacuolization of the endothelial cells were not infrequently demonstrated, total destruction of the endothelium was rarely seen. The interstitial changes included focal accumulation of edema fluid, particularly in the pericapillary spaces, patchy fibrosis, and increased cellularity. Particularly interesting were the altered alveolocapillary basement membranes which showed irregular thickening, lamination, and fragmentation. Irregular electron densities with derangement of internal ultrastructures were often observed in the matrices of isolated uremic lung basement membranes. The anionic binding sites characterized by cationized ferritins appeared to be irregularly and loosely arranged on the surfaces and in the interior of isolated basement membranes. In addition, abnormal deposition of aluminum was consistently detected in the precipitates of isolated basement membranes. From the aforementioned results we conclude that the present investigation provides the morphological data at the ultrastructural and molecular level to explain many of pulmonary physiological alterations and clinical manifestations exhibited by patients with chronic uremia.

Effects of adenosine on transmembrane potential and sarcolemmal Na+-K+ ATPase activity of human atrial myocardium

Adenosine effects on the transmembrane potential characteristics and the sarcolemmal Na+-K+ ATPase activity of human atrial myocardium were studied in tissue from 20 patients who were divided into 2 groups based on the maximum diastolic potentials (MDP) greater than or less than -60 mV. Group A consisted of 10 patients with MDP of 70.84 +/- 4.20 mV and Na+-K+ ATPase activity of 15.37 +/- 0.46 mumole Pi/mg/hr. Ten patients with MDP of 44.54 +/- 6.24 mV and Na+-K+ ATPase activity of 12.55 +/- 0.42 mumole Pi/mg/hr were included in group B. Adenosine had no effects on the electrophysiological properties and the sarcolemmal Na+-K+ ATPase activity of atrial myocardium at concentrations below 1 X 10(-5) M in either group. Adenosine resulted in mildly altered atrial transmembranes potentials without significant effect on Na+-K+ ATPase activity at concentrations between 1 X 10(-5) M and 5 X 10(-4) M. However, a significant reduction of transmembrane potentials and an apparent inhibition of Na+-K+ ATPase activity were observed only in tissue from group B. These results suggest that: 1) adenosine has no effect on the electrophysiological properties and the sarcolemmal Na+-K+ ATPase activity of human atrial myocardium at physiological concentrations; 2) adenosine induced inhibition of the sarcolemmal Na+-K+ ATPase activity in slow channel-dependent atrial tissues may be a mechanism responsible for the alterations of transmembrane potentials under unphysiological conditions; and 3) adenosine contributes to the genesis of cardiac arrhythmias during acute myocardial ischemia, which can reduce transmembrane potentials of the myocardial cells and may increase the myocardial adenosine level above its effective concentration.

Usefulness of intravenous diltiazem in predicting subsequent electrophysiologic and clinical responses to oral diltiazem

Diltiazem, 0.25 mg/kg, was given intravenously during induced tachycardias in 6 patients with atrioventricular (AV) nodal reentrant tachycardia (group I) and in 24 patients with AV reentrant tachycardia incorporating a retrogradely conducting accessory pathway (group II). In all 6 group I and in 15 of 24 group II patients, tachycardias terminated within 1 minute after diltiazem administration, with a weak link in the anterograde direction. In 3 other patients in group II, tachycardias were terminated by a premature ventricular complex within 1 minute. In the remaining 6 patients in group II, in whom tachycardias failed to terminate, rates of tachycardias decreased as a result of suppression of anterograde AV nodal conduction by diltiazem. Electrophysiologic studies were performed subsequently 2 hours after the third dose of 90 mg of diltiazem, which was given orally at 8-hour intervals. In 18 responders to intravenous diltiazem who were subjected to oral diltiazem testing, sustained supraventricular tachycardia (SVT) could be induced in only 2. Of the 6 nonresponders, sustained tachycardias could not be induced in 3. Twelve patients, including 11 responders and 1 nonresponder to intravenous diltiazem who responded to oral diltiazem testing, were discharged with oral diltiazem therapy, 90 mg every 8 hours, with follow-up periods of 2 to 13 months (mean 7 +/- 4 [+/- standard deviation]). The frequency of recurrent SVT decreased significantly; 8 patients were free of tachycardias and 4 had occasional recurrences of SVT that required no hospital visit. In conclusion, intravenous diltiazem is effective in terminating SVT. Termination of SVT by intravenous diltiazem predicts subsequent electrophysiologic and clinical responses to oral diltiazem.

Malignant fibrous histiocytoma at site of metal implant

The occurrence of malignant tumors at the site of metal implants is rare. The significance of this association is not settled. Its implications, however, are serious. A malignant fibrous histiocytoma arising at the site of an implant done 14 years ago for traumatic fracture of the femur in a 44-year-old man is reported. Previous reports are briefly summarized.

Structure of Marek's disease virus DNA: detailed restriction enzyme map

Purified virion DNA (120 X 10(6) molecular weight [MW]) of Marek's disease virus strain GA was cleaved with BamHI restriction endonuclease, and 27 out of the 29 fragments were cloned into bacterial plasmids. Restriction maps for BamHI, BglI, and SmaI endonucleases were constructed. The genomic structure of Marek's disease virus DNA was found to be similar to that of herpes simplex virus types 1 and 2. A long unique region (75 X 10(6) MW, located at 10 X 10(6) to 85 X 10(6) MW [10-85] from the left end of the genome), which was subdivided into segment 1 (22 X 10(6) MW, located at 10-32) and segment 2 (51 X 10(6) MW, located at 34-85) by direct repeats (32-34), was flanked by a long terminal region (10 X 10(6) MW, located at 0-10) and a long inverted region (10 X 10(6) MW, located at 85-95). A short unique region (8 X 10(6) MW, located at 103-111) was flanked by a short terminal region (8 X 10(6) MW, located at 111-119) and a short inverted region (8 X 10(6) MW, located at 95-103). The direct repeat fragments (0.9 X 10(6) could be isolated by cleavage with SmaI. The right terminal end was found to be heterogenous .

Cardiac dimensions and motion shortly after mitral valve surgery

We studied 71 adult patients echocardiographically both before and 2-16 days (mean 8 days) after mitral valve surgery to systematically evaluate the early postoperative changes in cardiac dimensions and motion. The patients were divided into 4 groups: group I with predominant mitral stenosis (MS) (26 patients), group II with predominant mitral insufficiency (MI) (12 patients), group III with MS + MI (16 patients) and group IV with combined mitral and aortic valvular disease (17 patients). After operation the left atrial dimension at endsystole decreased (mean +/- standard deviation, 56 +/- 12 mm vs 46 +/- 11 mm, p less than 0.001), but did not completely normalize in the majority of patients. The left ventricular dimension at enddiastole decreased in group II from 67 +/- 12 mm to 54 +/- 5 mm (p less than 0.01) and in group IV from 59 +/- 13 mm to 54 +/- 13 mm (p less than 0.01), but increased in group I from 43 +/- 8 mm to 46 +/- 9 mm (p less than 0.05). Mitral EF slope increased from 15 +/- 11 mm/sec to 52 +/- 20 mm/sec (p less than 0.001) after commissurotomy, and decreased from 136 +/- 61 mm/sec to 66 +/- 30 mm/sec (p less than 0.05) after annuloplasty. However, the postoperative means were subnormal in these subgroups. Paradoxical or hypokinetic septal motion occurred in 5/71 (7%) before and 50/71 (70%) after operation. We conclude that: 1) partial normalization of cardiac dimensions and subnormal mitral EF slopes shortly after mitral valve surgery suggest a residual pressure gradient across the mitral valve as well as partial irreversibility of the heart after longstanding mechanical overloading, and 2) postoperative abnormal septal motion, which may be caused by pericardiotomy, can occur after any type of open heart surgery.

Fetus-in-fetu: report of a case

A case of fetus-in- fetu is reported. It occurred in an 8-week-old Korean boy who had been born by cesarean section due to abdominal distension. The fetus-in- fetu was connected to the superior mesenteric artery and consisted of two masses, apparently representing two portions of an acardiac monster. There was an amniotic membrane covering both masses, and the umbilical cord clearly was identifiable. One mass included the brain, eye, trachea, salivary glands, thyroid, pancreas, spleen, etc., while the other mass contained extremity bones, vertebrae, testis, adrenals, and intestinal loops. This is probably a case of separated fetus-in- fetu that showed unusually well-developed internal organs.

Impulse responses of automaticity in the Purkinje fiber

We examined the effects of brief current pulses on the pacemaker oscillations of the Purkinje fiber using the model of McAllister , Noble, and Tsien (1975. J. Physiol. [Lond.]. 251:1-57). This model was used to construct phase-response curves for brief electric stimuli to find "black holes," where rhythmic activity of the Purkinje fiber ceases. In our computer simulation, a brief current stimulus of the right magnitude and timing annihilated oscillations in membrane potential. The model also revealed a sequence of alternating periodic and chaotic regimes as the strength of a steady bias current is varied. We compared the results of our computer simulations with experimental work on Purkinje fibers and pointed out the importance of modeling results of this kind for understanding cardiac arrhythmias.

Recording of auditory evoked potentials in man using chronic subdural electrodes

With the aid of chronic subdural electrodes we have been able to record from the posterior banks of the sylvian fissure, auditory evoked potentials (AEPs) that had morphologies and peak latencies compatible with the primary AEPs described by Celesia and Puletti (1969). These AEPs had amplitudes that were not only affected by the side of stimulus presentation but were maximal in an area close to the primary auditory cortex. The AEPs also displayed an extremely steep spatial gradient and were not altered by pentobarbitone sodium and nitrous oxide anaesthesia. Together, these properties suggest that these subdurally recorded potentials are near-field evoked potentials from the primary auditory cortex. The focal nature of these potentials also allows them to be used as effective electrophysiological tools for localization of the primary auditory cortex in patients.

Biochemical analysis and electron microscopy of human mitral valve collagen in patients with various etiologies of mitral valve diseases

Biochemical analyses and electron microscopy of mitral valve collagen were carried out in 29 patients with various mitral valve diseases. They were divided into 3 groups: (1) rheumatic heart disease (15 patients), (2) isolated rupture of chordae tendineae (8 patients), and (3) floppy mitral valve (6 patients). Normal mitral valves obtained at necropsy from 6 patients who died from extracardiac causes were used for control observations. Results of the electrophoretic analysis of the collagen of normal and diseased valves showed that all valves contained collagen types I, III, and AB collagen with similar electrophoretic patterns. Electron microscopic observations and comparisons of the segment-long-spacing crystallites of each type of collagen revealed similar band patterns, irrespective of the normal or diseased valves sources. It is concluded that the composition and primary molecular structure of mitral valve collagen are usually not altered in a wide variety of disease processes affecting the mitral valve.