Cytomegalovirus Isolation from a Chimpanzee with Acute Demyelinating Disease After Inoculation of Multiple Sclerosis Brain Cells

A strain of cytomegalovirus (CMV) was isolated during the third subcultivation of explants from the left frontal lobe of a chimpanzee that developed paralysis more than 3 years after intracerebral inoculation at birth with brain cell cultures derived from a patient with multiple sclerosis. Another strain of CMV was also isolated from a lymph node culture taken from the same chimp. The isolates, designated MZM-13 and MZM-14, produced a cytopathic effect characteristic for CMV when inoculated into brain, ganglion, or fibroblast cultures of human or simian origin. Infected cells contained characteristic Cowdry A intranuclear as well as intracytoplasmic inclusion bodies, and 100-nm spherical herpes-like virus particles were detected by electron microscopy in the nucleus and cytoplasm of infected cells. Virus was further identified as CMV with convalescent human anti-CMV serum. Complement-fixing antibody to CMV was present at a titer of 1:32 when the acutely ill chimpanzee was sacrificed. No antibody was detected at birth or at 1 or 2 years of age. A newborn chimpanzee inoculated intracerebrally with MZM-13 developed clinically asymptomatic lesions in the central nervous system characterized by acute and chronic inflammation and degeneration of myelin in cranial and spinal nerve roots. Restriction endonuclease analysis of viral deoxyribonucleic acid isolated from these two viruses indicated that MZM-13 and MZM-14 are identical and are closely related to chimpanzee CMV. No similarity in restriction endonuclease fragment patterns was found between MZM virus and the Towne and Clegg strains of human CMV.     

Immunohistochemical study of synphilin-1 in brains of patients with dementia with Lewy bodies - synphilin-1 is non-specifically implicated in the formation of different neuronal cytoskeletal inclusions

The caudal part of the fastigial nucleus, or the fastigial oculomotor region (FOR), plays an important role in executing accurate saccades. Inactivation of a monkey FOR leads to dysmetric saccades. Currently available data suggest that the dysmetria could be described as a parametric, uniform change in saccadic gain or, alternatively, as a constant error in the specification of the saccadic goal. To discriminate between these two possibilities, we examined the effect of FOR inactivation in the monkey. After a unilateral injection of muscimol into the FOR, ipsiversive saccades overshot a target. Gains were similar for movements of different sizes. The overshoot increased proportionately with the target distance and had a very small constant component. The present study indicates that the hypermetria of ipsiversive saccades after inactivation of the monkey FOR is primarily due to a uniform gain increase for all sizes of saccades.     

Beneficial effect of amrinone on murine cardiac allograft survival.

Amrinone is a non-glycoside positive inotropic agent with an inhibitory effect on a cyclic adenosine monophosphate (AMP) phosphodiesterase isoenzyme. In the present study, we examined the immunosuppressive action of amrinone, since several other cyclic AMP-elevating agents have been shown to suppress T lymphocyte activation. First, the in vivo effects of amrinone were investigated. Oral amrinone treatment, at 40 mg/kg per day, significantly prolonged median cardiac allograft survival compared with non-treated controls (22.0 days versus 10.5 days, P < 0.01) when DBA/2 mouse hearts (H-2d) were heterotopically transplanted into C57B1/6 mice (H-2b). Histopathological examination showed that there was less prominent cellular infiltration in the amrinone-treated than in the non-treated allografts. Plasma amrinone concentrations of mice after a single oral dose of 40 mg/kg were within the range of clinical relevance. To clarify the mechanism of action, in vitro studies were done. The generation of specific cytotoxic T lymphocytes after mixed lymphocyte culture was significantly suppressed by addition of amrinone to the culture medium at 5 micrograms/ml. The production of IL-2 and the interferon-gamma during mixed lymphocyte culture was also suppressed by amrinone at 5 micrograms/ml. However, the level of intracellular cyclic AMP in mouse splenic lymphocytes was not affected significantly by the same dose of amrinone. In conclusion, amrinone has immunosuppressive actions at the therapeutic doses, and it may be a beneficial agent for therapy against acute cardiac allograft rejection.     

Morphological and functional aspects of two different types of hair cells in the goldfish sacculus

1. With the use of whole-cell mode of the patch-clamp method, we examined the electrical responses of hair cells enzymatically isolated from the goldfish sacculus. 2. Hair cells from the rostral saccule had a short cell body and were ovoidal or eggplantlike in shape, whereas hair cells from the caudal saccule had a variable shape. Many had a longer cell body and were cylindrical or gourd-like in shape, but some short hair cells were also present in the caudal saccule. 3. The short hair cells had a resting potential of about -75 mV. In current-clamp experiments, these hair cells elicited damped oscillatory-potential changes of a relatively small amplitude in response to a depolarizing current. A current in the opposite direction produced a slow hyperpolarization, much larger in amplitude. 4. Resonant frequency of the short, or the oscillatory, type of hair cells ranged from 40 to 200 Hz or higher. However, resonance was generally of a poor quality as compared with that noted for hair cells in the turtle cochlea or frog sacculus. 5. The long hair cells had a resting potential of -90 to -100 mV. In current-clamp experiments, these hair cells elicited an all-or-none spike approximately 50 mV in amplitude in response to a depolarizing current. The spike was usually followed by a plateau, which was maintained for the duration of the depolarizing pulse. In some hair cells, damped slow oscillatory waves were evoked at a rate of 5-15 Hz. On the other hand, a hyperpolarizing current produced potential changes much smaller in amplitude. 6. Voltage-clamp experiments showed that Ca2+-activated K+ channel and A-current, especially its high-threshold subclass, were involved in the generation of outward rectification in the oscillatory-type hair cells. On the other hand, Na+, in addition to Ca2+, was involved in the generation of spike in the spike-type hair cells. Spike potentials were elicited even in the presence of tetrodotoxin (TTX), but the rate of rise was slower as compared with the intact spikes. 7. The spike-type hair cells had an inwardly rectifying K+ channel similar to that noted in the tunicate egg and chick vestibular hair cell. However, the oscillatory-type hair cells had an inwardly rectifying channel similar to the hyperpolarization-activated current, Ih, of the rod inner segment, or sinoatrial nodal cell, or lacked the inwardly rectifying channel. Differences in the resting membrane potential between the oscillatory- and spike-type hair cells are probably related to differences in the inwardly rectifying channels. 8. Effects of sound stimulation were simulated by injecting a half-wave rectified sinusoidal current of various frequencies.(ABSTRACT TRUNCATED AT 400 WORDS)     

Human thymus-lymphoid tissue antigen and its presence in leukaemia and lymphoma

An antiserum was prepared by immunizing rabbits with human leukaemic tissue homogenate. Prior to immunization, the rabbits had been made tolerant to normal peripheral leucocytes by repeated injections during the neonatal period to suppress the appearance of antibodies against normal tissue components. When the antiserum was tested by gel diffusion precipitation test, it gave one precipitin line against malignant tissue extracts from most leukaemia and lymphoma cases tested, and against normal thymuses and some spleens and lymph nodes as well. It did not react with tissue extracts prepared from normal non-lymphoid tissus. The antigen responsible for the reaction appeared in foetal thymus at 3 months of gestation and persisted throughout life. It appeared in embryonic spleen after 6 months of gestation and in lymph nodes even later, although in spleen and lymph nodes it was not as invariably demonstrated as in the thymus. Neoplasms of other than lymphoid origin were predominantly negative for the antigen; occasional exceptions were probably due to large amounts of infiltrating lymphoid tissue. Antigen localization was studied by the fluorescent antibody method. The cytoplasm of almost all thymocytes, about 30% spleen cells and 20–40% peripheral lymphocytes was stained. Bone marrow, brain, thyroid, liver and kidney cells were negative. The antigen was partially purified from the soluble fraction of thymus homogenate by ion exchange column chromatography and preparative electrophoresis. Its possible use as a marker for thymus derived normal and neoplastic cells has been discussed.     

Potential tumor suppressive pathway involving DUSP6/MKP-3 in pancreatic cancer

We previously found frequent loss of heterozygosity at 12q21 and 12q22-q23.1 in primary pancreatic cancers, and the DUSP6/MKP-3 gene residing in this region at 12q22 lost its expression in the great majority of pancreatic cancer cell lines. The DUSP6/MKP-3 protein is a dual-specificity phosphatase that dephosphorylates the active form of ERK, making a feedback loop to control ERK activity. Gain-of-function mutations of KRAS2 occur in the great majority of pancreatic cancer cells, and loss of expression of DUSP6/MKP-3 may synergistically promote constitutive activation of ERK and uncontrolled cell growth. To study loss of the feedback pathway and its impact on pancreatic cancer cell growth, we first investigated the expression of DUSP6/MKP-3 in primary pancreatic cancer tissues immunohistochemically; we found up-regulation in mildly as well as severely dysplastic/in situ carcinoma cells and down-regulation in invasive carcinoma, especially in the poorly differentiated type. Adenovirus-mediated reintroduction of DUSP6/MKP-3 into cultured pancreatic cancer cells induced strong expression of recombinant DUSP6/MKP-3 and reduction of phosphorylated ERK in a dose-dependent manner based on the multiplicity of infection and resulted in suppression of cell growth. Moreover, analyses by flow cytometry and immunocytochemistry revealed that the exogenous expression of DUSP6/MKP-3 induced apoptosis. These results show that DUSP6 exerts apparent tumor-suppressive effects in vitro and suggest that DUSP6 is a strong candidate tumor suppressor gene at 12q22 locus.     

PRQFVamide,a novel pentapeptide identified from the CNS and gut of Aplysia

We have purified a novel pentapeptide from the Aplysia nervous system using bioassay on gut contractions. The structure of the peptide is Pro-Arg-Gln-Phe-Val-amide (PRQFVa). The precursor for PRQFVa was found to code for 33 copies of PRQFVamide and four related pentapeptides. Peaks corresponding to the predicted masses of all five pentapeptides were detected in Aplysia neurons by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Northern analysis revealed that expression of the precursor is abundant in the abdominal ganglion, much less in the pedal and cerebral ganglia, and rarely seen in the buccal and pleural ganglia. PRQFVa-positive neurons, mapped by immunohistochemistry and in situ hybridization, were present in all the central ganglia. PRQFVa immunopositive processes were observed in the gut, particularly in association with the vasculature. Some arteries and other highly vascularized tissues, such as the gill and the kidney, also contain numerous PRQFVa immunopositive processes. Application of synthetic PRQFVa suppresses not only contractions of the gut but also contractions of vasculature. PRQFVa is expressed in some of the neurons within the feeding circuitry and application of synthetic PRQFVa was found to decrease the excitability of some (B4/5 and B31/32) but not all (B8) neurons of the buccal feeding circuit. Our findings suggest that PRQFVa may act as a modulator within the feeding system as well as in other systems of Aplysia.     

The effect of immunoglobulin G1 structure on macrophage binding to supported planar lipid monolayers.

We have studied the antibody-dependent binding of macrophages to supported planar lipid monolayers containing haptenated phospholipids (Tnp-Cap-DPPE). Eight monoclonal anti-TNP IgG1s, which had similar affinities to the TNP residues in solution and in the membranes, were used in the experiment. The results showed that mouse macrophages (P388D1 and J774.1) bound with different affinities to these IgG1-coated lipid monolayers. The monoclonal antibody shown to be deficient in macrophage binding was also relatively ineffective in activating complement. These results indicated that individual monoclonal antibodies of a given subclass may prove deficient in terms of the biological activities associated with the group as a whole.     

Follow-up study in a patient with Setleis syndrome

We report on an 8-year-old Japanese boy with Setleis syndrome. The patient had a very characteristic “coarse” facial appearance, bitemporal “forceps marks,” skin aplasia, sparse hair, and skin hypo- and hy-perpigmentation. He also had previously undescribed manifestations, including an aberrant hair pattern of the forehead, linear skin lesions on the forehead, short palpebral fissures, a small skin tag on the right cheek, cone-shaped teeth, and pectus carinatum. Dermatoglyphic studies documented aberrant distal palmar creases (simian crease variant), 8 arches, and reduced total finger ridge count. When serial photographs were reviewed, his facial characteristics became more obvious with increasing age. © 1995 Wiley-Liss, Inc.     

Tolerance to self gangliosides is the major factor restricting the antibody response to lipopolysaccharide core oligosaccharides in Campylobacter jejuni strains associated with Guillain-Barré syndrome

Guillain-Barré syndrome following Campylobacter jejuni infection is frequently associated with anti-ganglioside autoantibodies mediated by molecular mimicry with ganglioside-like oligosaccharides on bacterial lipopolysaccharide (LPS). The regulation of antibody responses to these T-cell-independent antigens is poorly understood, and only a minority of Campylobacter-infected individuals develop anti-ganglioside antibodies. This study investigates the response to gangliosides and LPS in strains of mice by using a range of immunization strategies. In normal mice following intraperitoneal immunization, antibody responses to gangliosides and LPS are low level but can be enhanced by the antigen format or coadministration of protein to recruit T-cell help. Class switching from the predominant immunoglobulin M (IgM) response to IgG3 occurs at low levels, suggesting B1-cell involvement. Systemic immunization results in poor responses. In GalNAc transferase knockout mice that lack all complex gangliosides and instead express high levels of GM3 and GD3, generation of anti-ganglioside antibodies upon immunization with either complex gangliosides or ganglioside-mimicking LPS is greatly enhanced and exhibits class switching to T-cell-dependent IgG isotypes and immunological memory, indicating that tolerance to self gangliosides is a major regulatory factor. Responses to GD3 are suppressed in knockout mice compared with wild-type mice, in which responses to GD3 are induced specifically by GD3 and as a result of polyclonal B-cell activation by LPS. The anti-ganglioside response generated in response to LPS is also dependent on the epitope density of the ganglioside mimicked and can be further manipulated by providing secondary signals via lipid A and CD40 ligation.