Herpes simplex virus encephalitis: laboratory evaluations and their diagnostic significance

Laboratory procedures were compared with brain biopsy findings in 113 biopsy-proven patients with herpes simplex virus (HSV) encephalitis and 93 biopsy-negative individuals. Examinations of brain tissue by histopathology, immunofluorescence, and electron microscopy demonstrated evidence of HSV infection in 56%, 70%, and 45% of proven cases and apparently false-positive results in 14%, 9% and 2% of those biopsy-negative. Serologic assessments revealed that HSV encephalitis occurred as both a primary (30%) and recurrent (70%) infection. Among patients with HSV encephalitis, 28% failed to seroconvert or seroboost within one month of the onset of disease. Titers of passive hemagglutinating and IgG immunofluorescent antibodies increased fourfold in the cerebrospinal fluid in 74% and 94%, respectively, of patients with proven disease. Similar percentages of patients had antibody ratios in serum and cerebrospinal fluid of less than 20 over the same interval. These data indicate the need for development of noninvasive diagnostic procedures.

[Studies on the therapeutics of experimental toxoplasmosis. II. Effect of acetylspiramycin alone or in combination with an immunopotentiator (CSP-II) or sulfamethopyrazine on Toxoplasma multiplication in the heart of mice acutely and chronically infected with Toxoplasma gondii (author's transl)]

Normal mice acutely and chronically infected with the S-273 strain of T. gondii, were treated with acetylspiramycin (ASPM) alone, 8 mg/mouse/day, per os, or in combination with an immunopotentiator (CSP-II), 10 mg/mouse/day, intraperitoneally, or sulfamethopyrazine (SMPZ), 2 mg/mouse/day, per os, for a period of 4 weeks. In the acute cases, a 99.4% cyst reduction was obtained with ASPM alone and no cysts were seen in the brains of mice treated with ASPM in combination with CSP-II or SMPZ. The organisms were significantly eradicated in the brain and heart tissues of mice treated with ASPM alone or in combination with CSP-II or SMPZ as shown by subinoculation to normal mice and the negative latex hemagglutination titers of the recipient mice. In the chronic cases, a cyst reduction of 52.4% was obtained with mice treated with ASPM in combination with CSP-II. A cyst reduction of 34.6%, 32.9% and 20.8% was obtained in the ASPM alone, CSP-II alone and ASPM in combination with SMPZ treated groups, respectively. A comparative clearing of the organisms in the heart tissues of mice treated with ASPM in combination with CSP-II was obtained compared to the other treatment groups but not in the brains of all groups.

Mechanisms for induction of drinking with special reference to angiotensin II

The Japanese quail drinks water vigorously after water deprivation, haemorrhage and administration of hypertonic saline solution. Most avian species responded to angiotensin II (AII) by drinking, but carnivorous birds and those originating in arid regions were insensitive. The receptive sites for AII were the subfornical organ (SFO) and the preoptic area (POA) in the Japanese quail. Catecholaminergic fibers proceed from the POA to the SFO. Dipsogenic information generated by AII at the POA is transferred to the SFO through the catecholaminergic nerve fibres. Plasma AII increased following dehydration and haemorrhage and returned to a normal level immediately after rehydration. Following dehydration, arginine vasotocin, aldosterone and corticosterone increased in plasma as well as AII. A single intraperitoneal injection of AII induced increases of arginine vasotocin, aldosterone and corticosterone in plasma. It seems that AII functions as a trigger for release of these other hormones during dehydration.

Production and properties of Toxoplasma growth inhibitory factor (Toxo-GIF) and interferon (IFN) in the lymphokines and the circulation of Toxoplasma immune mice

Assessment in vitro were carried out to study Toxo-GIF and IFN in lymphokines, LKs, produced by immune spleen cells with Toxoplasma lysate antigen (TLA). LKs were obtained from the cells after incubation for 24 to 48 h with TLA. They inhibited almost completely the intracellular multiplication of Toxoplasma (Tp) within homologous cells. Peak IFN activities were observed in the same LKs. The IFN was inactivated at pH 2, but did not lose its activity at 56 degrees C, suggesting that it might be type II or gamma IFN. Further evidence was presented of the coordinate production and properties of Toxo-GIF and IFN in the circulating blood of Tp-immune mice injected intraperitoneally with TLA or Poly I: C. The IFN was designated type II or gamma IFN. Its maximum activity appeared in Tp-immune mice 6 h after TLA or Poly I: C injection, while a maximum Toxo-GIF activity was observed in these mice 24 to 48 h after injection. Type I IFN activity was detected in the serum of normal mice injected with TLA or Poly I: C. Type I IFN differed markedly from type II IFN, because it was stable at pH 2 and unstable at 56 degrees C. Evidence was presented which emphasized the difference in activity in relation to the time of appearance between Toxo-GIF and IFN.

Ultrastructural study of intracranial yolk sac tumor: with special reference to the oncologic phylogeny of germ cell tumors

Ultrastructural studies of yolk sac tumors (YST) have generally demonstrated the resemblance of this neoplasm to the primitive human yolk sac. However, these studies have failed to explain the common occurrence of mixed germ cell tumors with yolk sac elements. This report describes the ultrastructural features of a suprasellar YST. This tumor resembled those previously described. Also demonstrated, however, was the presence of primitive germ cells admixed within the neoplasm. A new schema is proposed based on these observations for the interrelationship of germ cell tumors, which may explain the common occurrence of mixed germ cell tumors.

Rapid detection of viruses in biopsy or autopsy specimens by the pseudoreplica method of electron microscopy

A rapid pseudoreplica method of electron microscopy (EM) was used to detect viruses in brain tissues obtained from 57 patients suspected of having herpes simplex encephalitis (HSE). Herpesvirus particles were demonstrated in 18 of the 20 (90%) specimens from which herpes simplex virus was isolated in tissue culture. The procedure takes less than 2 hours, as compared to the time (greater than or equal to 2 days) usually required for virus isolation or standard thin-section electron microscopy. Although the immunofluorescence test has comparable rapidity, it was found to be less sensitive and to yield occasionally false-positive reactions. Our findings indicate that, until a brain biopsy can be replaced by less invasive procedures, examination of brain tissue by the pseudoreplica method offers a rapid diagnosis of a herpesvirus encephalitis. Furthermore, the demonstration of viruses in brain, lung and liver specimens obtained by biopsy or at autopsy suggests that this electron-microscopic method would be advantageous for detecting viruses in tissue samples, particularly in the case of viruses which may not be readily demonstrable by conventional methods.

Microbicidal activity of toxoplasma immune beagle plasma and lymphokines to toxoplasma multiplication in host cells

In beagles infected with Toxoplasma tachyzoites, IgM and IgG humoral antibodies appeared on the early period of infection as the expression of the humoral antibody response. IgM antibody was no longer observed after 16 days, however, IgG antibody persisted maintaining high titers up to the last day of the experiment. When challenged on the 13th day postinfection, IgG antibody levels were boosted, however, IgM levels did not show any change at all. Lymphokines obtained from spleen cells collected 10, 30, 100 and 300 days postinfection showed a gradual increase in the ability to inhibit Toxoplasma multiplication in normal canine monocytes accordingly compared to the control which showed no inhibition at all. Toxoplasma lysate antigen was injected intravenously to hyperimmuned dog 2 wk after rechallenge. Plasma collected 24 hr after injection inhibited markedly Toxoplasma multiplication. No change in the microbicidal activity was found when plasma was absorbed with anti-canine IgG compared to the unabsorbed one. The results therefore indicated that the substance inhibiting Toxoplasma multiplication in canine monocytes existing in plasma is not derived from antibodies specific for Toxoplasma but as a Toxoplasma growth inhibitory factor (Toxo-GIF) or a similar substance. The plasma obtained also showed antiviral activity of interferon type II and was found to increase in the circulation 6 hr after Toxoplasma lysate antigen injection.

[Erythema rheumaticum]

A case of typical erythema rheumaticum is presented with emphasis on clinical, histological, immunopathological and immunological findings. Pathogenesis and therapy are shortly discussed.

Cerebellar "neuroblastoma": nosology as it relates to medulloblastoma

Medulloblastoma is a relatively common and well-established entity, consisting of primitive, multipotential cells that may exhibit some evidence of neuroblastic or glial differentiation. However, cerebellar "neuroblastoma" with ultrastructural evidence of significant neuroblastic differentiation are extremely rare. We have studied three tumors with light microscopic evidence of neuroblastic differentiation. All of these tumors have regions resembling medulloblastoma; this finding suggests that cerebellar "neuroblastoma" represents one form of medulloblastoma. These cases provide further evidence for the potential medulloblastoma cells to differentiate along neuronal lines.

An in vitro study on the toxoplasmacidal activity of lonomycin A in host cells

Lonomycin A at various concentrations was tested for its inhibitory effect on Toxoplasma multiplication in host cells cultured in vitro. Results indicate that lonomycin A at a concentration of 0.01 micrograms per ml in TC-199 medium demonstrated a high degree of antitoxoplasma activity with complete inhibition of Toxoplasma multiplication in the host cells. Lymphokines, a supernatant produced from spleen cells of mice infected chronically with Toxoplasma gondii, inhibited Toxoplasma multiplication in mice macrophage and kidney cell monolayers. However, lonomycin A inhibited completely Toxoplasma multiplication in non-specific cells, i.e. not only in mice macrophages and kidney cells but also in cells of human and other animal species.

Protective reaction against malaria infection in mice sensitized with Frozen-thawed toxoplasma tachyzoites

Mice sensitized with frozen-thawed Toxoplasma antigen emulsified in Freund's Incomplete Adjuvant (FIA) showed high resistance against Plasmodium berghei infection, but not in mice sensitized with paraformaldehyde-fixed. Toxoplasma or saline plus FIA. However, mice which survived from malaria infection did not show any protective reaction against the RH strain inoculation. Furthermore, an immune interferon activity was detected in the supernatant of the spleen cells collected from the mice sensitized with frozen-thawed Toxoplasma and cultured with the specific antigen, however, no Toxoplasma growth inhibitory factor (Toxo-GIF) was found in the same supernatant of lymphokines. From these results, it is suggested strongly that frozen-thawed Toxoplasma antigen could confer nonspecific resistance in mice against Plasmodium infection.

Intraventricular neuroblastoma in a patient wit von Hippel-Lindau's disease. Light and electron microscopic study

Cerebral neuroblastoma is a rare neoplasm that has not previously been associated with a phakomatosis. We report a case of an intraventricular neuroblastoma in a patient with Von Hippel-Lindau's disease. The neoplasm consisted of process-forming cells containing clear vesicles, dense-cored granules and microtubules. An unusual finding was the presence of intertwining cytoplasmic processes, apparently representing aberrant process formation. We suggest that this case represents a cerebral neuroblastoma occurring as an unusual manifestation of a phakomatosis.

Cystic prolactinoma: a variant of "transitional cell tumor" of the pituitary

Pituitary tumors with features of both Rathke's cleft cysts and adenohypophysial adenomas are extremely rare and have been termed "transitional cel tumors." The ultrastructural features of one of these tumors has been reported, demonstrating cells with features transitional between those of adenohypophysial cells and Rathke's cleft cells, along with other cells with the distinctive features of either cell type. We report a case of a prolactin-secreting "transitional cell tumor" with similar light-microscopic and ultrastructural features. Additionally, the transitional cells in our case exhibited abundant intracellular mucin production. This represents a variant of "transitional cell tumor" of the pituitary gland.

Benign hemangioendothelioma involving the central nervous system: "strawberry nevus" of the neuraxis

Benign hemangioendothelioma is rarely included in discussions of vascular neoplasms involving the central nervous system, whereas it is a well-defined entity outside the neuraxis. We present four cases of benign hemangioendothelioma, including an infantile hemangioendothelioma with venous drainage into the transverse dural sinus, an intracranial hemangioendothelioma adherent to the falx cerebri, a spinal epidural hemangioendothelioma causing spinal cord compression, and a parasellar hemangioendothelioma. Although hemangioendothelioma resembles hemangioblastoma in some ways, it is a distinct entity differing from the other vascular lesions involving the central nervous system.

Acid phosphatase in eyes with pseudoexfoliation

We studied the activity of acid phosphatase in the anterior segment of the eye with pseudoexfoliation histochemically and biochemically. Light and electron microscopic histochemistry revealed lead precipitates indicating acid phosphatase activity in pseudoexfoliative materials. Biochemical assay for acid phosphatase was significantly higher in the aqueous humor of eyes with pseudoexfoliation than in that of cataractous eyes without pseudoexfoliation.

Ultrastructural study of the human neurohypophysis. III. Vascular and perivascular structures

The vascular and perivascular regions of the human neurohypophysis were studied electron microscopically. The abluminal basement membrane, perivascular space, luminal basement membrane and endothelium are interposed between the neural parenchyma and the blood stream. The capillaries are fenestrated, with pores measuring 30 to 50 nm in diameter. The perivascular and intercellular spaces form prominent networks that penetrate between rows of neurohypophysial parenchymal cells. The perivascular space contains pericytes, histiocytes, fibroblasts and mast cells, with ultrastructural features typical of each cell type. No transitional forms between histiocytes and pericytes were observed. A schema for the extracellular flow of neurohypophysial hormones through the sinusoidal and perivascular spaces is proposed, suggesting an important role for the pituicytes and their intercellular junctions in the control of hormone release.

Ultrastructural study of the human neurohypophysis. II. Cellular elements of neural parenchyma, the pituicytes

The pars nervosa of the neurohypophysis from 12 patients undergoing hypophysectomy for palliative treatment of advanced carcinoma was studied electron microscopically. Special attention was given to the cellular elements, the pituicytes. Five different classes of pituicytes, with various transitional forms, were elucidated based on their ultrastructural characteristics: (1) The most common type, referred to as "major pituicytes", is reminiscent of astrocytes. (2) "Dark pituicytes" are thought to represent different functional stages of the "major pituicytes". (3) "Ependymal pituicytes" are believed to provide ultrastructural evidence that human pituicytes are phylogenetically derived from ependymal cells. (4) "Oncocytic pituicytes" were observed in all cases and are of unknown significane. (5) The ultrastructural features of "granular pituicytes" suggest the existence of an active uptake and catabolism of extracellular material by pituicytes, probably through "ultraphagocytosis" or "endocytosis". These five classes of pituicytes are considered to represent different functional forms of one cell line that originates phylogenetically from the ependyma.

Ultrastructural study of the human neurohypophysis. I. Neurosecretory axons and their dilatations in the pars nervosa

Neurosecretory axons and their dilatations in the pars nervosa of the human neurohypophysis were studied electron microscopically. The axons are of two different types based on their content of neurosecretory granules (NSGs): (i) NSGs of Type A are 100-300 nm, and (ii) NSGs of type B are 50-100 nm in diameter. While fibers (or axons) of type B were scarce, showing simple swellings and terminal formations, fibers of type A were ubiquitous in the human pars nervosa, exhibiting numerous dilatations with a diversity of internal structure, apparently representing the ultrastructural manifestation of intraaxonal turnover of neurohypophysial hormones. Based on the predominating aspect of their internal structure, dilatations of type A-fibers were classified into six different types, with various transitional forms: Type I is characterized by abundant NSGs; type II by prominent mitochondria; type III by abundant lysosomal bodies; type IV by an electron-lucent matrix with few organelles; type V by prominent tubuloreticular profiles; and type VI by numerous microvesicles. The functional significance of each type is discussed and a scheme of possible interrelationships between these dilatations is proposed.