Malignant small bowel neoplasm of enteric plexus derivation (plexosarcoma). Light and electron microscopic study confirming the origin of the neoplasm

An unusual small intestinal tumor was found in a 61-year-old male who complained of intermittent right lower quadrant burning pain, tenesmus, and bloody diarrhea. On gross examination, the tumor was located intramurally in the distal jejunum with no involvement of the overlying mucosa. Histologic examination revealed two elements: a spindle cell component with characteristics reminiscent of a Schwann cell neoplasm, and nests of larger epithelioid-like cells almost undistinguishable from the Zellballen of nonchromaffin paragangliomas. The neoplasm originated within the intestinal wall without apparent mucosal origin. Ultrastructural studies revealed features recapitulating the normal enteric plexus structure and quite unlike those described in normal or neoplastic smooth muscle, Schwann or paraganglion cells. On this basis, this neoplasm is considered as a malignant enteric plexus tumor or a plexosarcoma.

Clinical significance and partial biochemical characterization of lactate dehydrogenase isoenzyme 6

We report nine patients with a sixth band, migrating cathodic to lactate dehydrogenase 5, appearing on routine electrophoresis for serum lactate dehydrogenase (LD, EC 1.1.1.27). Eight of these patients died during their hospitalization. Acidosis, hypotension, and sepsis were the common clinical conditions preceding the band's appearance. In several cases the band appeared transiently. We examined tissue samples from two of the cases, finding LD-6 in liver and skeletal muscle but not in heart. In randomly selected autopsy tissues, LD-6 was detected consistently in liver and skeletal muscle, sometimes in spleen, kidney, and adrenal tissue, but never in heart. Biochemical studies indicate that the LD-6 isoenzyme is not an artifact or an immunoglobulin complex, is larger than the other LD isoenzymes, contains an M-subunit but not an H-subunit, has an isoelectric point in the pH range of 9.0-9.6, and is more heat stable than LD-5.

Clinical significance and partial biochemical characterization of lactate dehydrogenase isoenzyme 6

We report nine patients with a sixth band, migrating cathodic to lactate dehydrogenase 5, appearing on routine electrophoresis for serum lactate dehydrogenase (LD, EC 1.1.1.27). Eight of these patients died during their hospitalization. Acidosis, hypotension, and sepsis were the common clinical conditions preceding the band's appearance. In several cases the band appeared transiently. We examined tissue samples from two of the cases, finding LD-6 in liver and skeletal muscle but not in heart. In randomly selected autopsy tissues, LD-6 was detected consistently in liver and skeletal muscle, sometimes in spleen, kidney, and adrenal tissue, but never in heart. Biochemical studies indicate that the LD-6 isoenzyme is not an artifact or an immunoglobulin complex, is larger than the other LD isoenzymes, contains an M-subunit but not an H-subunit, has an isoelectric point in the pH range of 9.0-9.6, and is more heat stable than LD-5.

Functional carotid paragangliomas. Biochemical, ultrastructural, and histochemical correlation with clinical symptoms

To our knowledge, this study is the first to correlate the results of biochemical, electron microscopic (EM), and histochemical analyses of tissues from functional paragangliomas of the upper carotid area with a patient's clinical symptoms. The tumor tissues from our two patients contained epinephrine, norepinephrine, and dopamine. Neurosecretory granules were identified in both tumors by EM and by the Grimelius silver stain. The patient with the most severe symptoms exhibited evidence of higher circulating levels of catecholamines by biochemical, EM, and histochemical analyses.

Squamous cell carcinoma metastatic to placenta and ovary

A woman previously treated for squamous cell carcinoma of the neck underwent a cesarean section for fetal distress. Extensive metastases of the placenta and an ovary were histologically compatible with her prior malignancy. Diffuse infiltration of the placenta by this neoplastic process was associated with an infant who was small for gestational age and who had no evidence of metastatic disease.

Membranous nephropathy in a renal allograft. Its occurrence in a patient with previous anti-glomerular basement membrane disease

Glomerulonephritis (GN) in transplant recipients has been attributed to recurrent as well as de novo disease. Although GN is thought to be common in renal allografts, few documented cases of de novo membranous GN in renal allografts have been reported. To our knowledge, this is the second reported case of membranous nephropathy of a renal allograft in a patient whose original disease was anti-glomerular basement membrane disease.

Organization of the medial hypothalamus for control of adrenocorticotropin in the cat

To examine the role and interrelations of areas of the medial hypothalamus in the control of release of ACTH, we stimulated electrically (20-sec train, 200-microamperemeter amplitude at 100 Hz) 695 sites in the hypothalamus of 91 cats anesthetized with chloralose-urethane. Changes in ACTH were measured by RIA. Responses of arterial pressure could not account for changes of release of ACTH. Several ACTH-active areas were defined. The anatomical relations of these areas with known nuclei and pathways then were considered. Two ACTH facilitatory areas and one ACTH inhibitory area were identified in the lateral aspect of the medial hypothalamus. The dorsal facilitatory area appears to be an extension of the lateral division of the dorsolongitudinal fasciculus and to extend medially to join the Fields of Forel, the ventral tegmental area of Tsai, and the parvocellular, paraventricular, and periventricular nuclei. The ACTH inhibitory area appears to be an extension of portions of the central tegmental tract and to extend medially to the posterior hypothalamic area and the dorsal hypothalamic area and ventrally toward the basal hypothalamus. The ventral ACTH facilitatory area appears to be coincident with the medial forebrain bundle and to extend anteroventrally and medially through the supraoptic decussation to the suprachiasmatic, ventromedial, dorsomedial, periventricular, infundibular, and premammillary nuclei. Stimulation of the median eminence led to increased release of ACTH. The results suggest that ascending pathways from the lower brainstem mediating control of ACTH project to discrete areas of the hypothalamus and then converge on the medial basal hypothalamus.

Inhibitory and facilitatory areas of the rostral pons mediating ACTH release in the cat

To define the role of the rostral pons in the control of release of ACTH, we stimulated electrically (30 sec, 200 muA, 50 Hz) 128 sites in the dorsal rostral pons of 20 cats anesthetized with chloralose/urethane. Responses of arterial pressure to electrical stimulation were prevented by lesions placed previously in the medulla. Plasma concentrations of ACTH were measured by radioimmunoassay. Active areas consisted of three regions: 1) lateral inhibitory: Locus subcoeruleus and anteroventral locus coeruleus (mean deltaACTH: -189, -164, -145 pg/ml at 1.5,3.0 and 6.0 min respectively, P less than 0.01);2) intermediate facilitatory:principal locus coeruleus and lateral ventral tegmental nucleus (mean deltaACTH: +81, +68, +37 pg/ml; P less than 0.05); and 3) medial inhibitory: dorsal tegmental nucleus, dorsal raphé and medial ventral tegmental nucleus (mean deltaACTH; -211, -212, -115 pg/ml; P less than 0.01). The former two areas received direct projections from medullary neurons activated or inhibited by atrial stretch, and, in turn, give rise to adrenergic and cholinergic projections to the medial hypothalamus. Since the release of ACTH is inversely correlated with right atrial stretch, the results suggest that the lateral inhibitory area and the intermediate facilitatory area are involved in mediation of changes in release of ACTH in response to hemodynamic changes.

Hypothalamic cells in an area mediating ACTH release respond to right atrial stretch

The right atrium has been shown to mediate release of ACTH in response to small hemorrhage. Therefore, we sought to identify hypothalamic neurons (cat, alpha-choloralose 35-45 mg/kg) wholse firing rates were modulated by stretch of the right atrial-vena caval junction. Stretch was produced by intermittent inflation of a balloon implanted between the pericardium and the right atrium. In some cases, carotid arteries were occluded bilaterally. Previous results indicate that electrical stimulation of the medial-dorsal hypothalamus (MDH) causes prompt changes in ACTH, but stimulation in the lateral hypothalamus does not cause changes. Of 64 cells recorded in the MDH, 41 responded to atrial stretch. However, only 2 of 18 cells outside this region responded. Six cells were studied with and without carotid occlusion. Their response was dimished or absent in the absence of carotid occlusion. The results suggest that integration of afferent signals from cardiovascular receptors occurs in the MDH and that the MDH may participate in neural mediation of ACTH in response to hemodynamic changes.