New concept of spinal orthosis for weakened back muscles

An anterior bending posture of the trunk during walking is often seen among the elderly commonly due to weakened thoraco-lumbar and gluteal muscles. For the management of this debilitating condition, the authors have developed a modified design of thoraco-lumbosacral orthosis (TLSO). Incorporated in this device are pockets for the accommodation of lead weights, which are located posteriorly at the level of the lumbar region and an elasticated anterior abdominal band. The results and level of patient acceptance achieved with the use of this brace have both been excellent.

Characterization of intermediate T-cell receptor cells expanding in the liver, thymus and other organs in autoimmune lpr mice: parallel analysis with their normal counterparts

Autoimmune MRL-lpr/lpr (lpr) mice were previously demonstrated to have an abnormal proliferation of intermediate T-cell receptor (TCR) cells of extrathymic origin in the liver. Despite this situation, thymectomy in lpr mice resulted in amelioration of autoimmune disease. To understand the underlying mechanism, we investigated associated T-cell differentiation in the thymus and other organs of these mice. When the disease was evoked, T cells with extrathymic properties, i.e. intermediate TCR-alpha beta cells expressing double-negative (DN) CD4-8- phenotype and interleukin-2 (IL-2) receptor beta-chain, became prominent not only in the liver, but also in the thymus. Such thymic T cells mainly resided in the medulla. A small-scale localization of such T cells was seen in the thymic medulla even in normal control mice. There was a heterogeneity among intermediate TCR cells in terms of the composition of DN cells and the expression of CD2 and B220 antigens, depending on the organs and the sites in the same organ. Intermediate TCR cells in the liver, thymus and autoimmune target organs (e.g. kidney) contained a high proportion of the active form (CD2+B220-), while intermediate TCR cells accumulating in peripheral organs, the spleen and lymph nodes, were mainly of the inactive form (CD2-B220+). The active form had an ability to proliferate in response to IL-2 and SEB, whereas the inactive form did not. The present results suggest that the proliferation of intermediate TCR cells occur at multiple sites; this may explain the effect of thymectomy, namely, the retarded onset of disease, in lpr mice.

[Clinical study of radiation pneumonitis over 10 years]

We studied clinical aspects of radiation pneumonitis from 1983 to 1992. Fifty seven patients admitted to our hospital because of lung cancer were treated with radiotherapy, and radiation pneumonitis developed in 20 (35.1%). The incidence of radiation pneumonitis was closely related to male sex, chronic obstructive lung disease, and chemotherapy. Pneumonitis was not related to age, or to the area or amount of radiation. Eighteen cases (90%) of pneumonitis occurred during or within one month after radiotherapy. In all but five cases (25%), pneumonitis was limited to the area of radiation. Treatment was mainly with steroids. In 4 cases (20%), pneumonitis recurred when steroid therapy was reduced, and five patients (10%) died.

Extrathymic T cells stand at an intermediate phylogenetic position between natural killer cells and thymus-derived T cells

A series of recent studies have revealed that extrathymic pathways of T cell differentiation exist at multiple sites in mice and humans. In terms of their properties, extrathymic T cells may stand at an intermediate position between natural killer (NK) cells and thymus-derived T cells in phylogenetic development. It is speculated that primitive lymphocytes such as NK cells and extrathymic T cells develop from primordial macrophages in intraepithelial regions of e.g., the intestine, skin and liver. In this regard, the immune system of the bone marrow and thymus is relatively recent, developing after the emergence of living beings onto the land (i.e., amphibia). A complete elimination of self-reactive T cell clones occurs in mainstream intrathymic T cell differentiation and a consistent generation of such clones occurs through the extrathymic pathways. Therefore, thymus-derived T cells are efficient for processing foreign antigens, whereas extrathymic T cells recognize abnormal self-cells. Although thymus-derived T cells play the major role in youth, extrathymic T cells may play rather a pivotal role with aging and under conditions of malignancy, intracellular infections, pregnancy, and autoimmune diseases.

[Decrease of nosocomial bacteremia and nosocomial pneumonia after introduction of preventive measures of hospital infection]

In the early 1980's methicillin-resistant staphylococcus aureus (MRSA) was reported as a major pathogenic organism of geriatric hospital infection in Japan. At the same time in the A geriatric hospital MRSA infection was prevalent. To decrease nosocomial infections some active preventive measures against hospital infection were taken since Oct. 1991. About a year before introduction of prevention of hospital infection in the geriatric ward (190 beds) of A hospital 193 episodes of nosocomial bacteremia were observed. However a year after introduction of preventive measures episodes of nosocomial bacteremia were decreased to less than a half (45.6%) in comparison to the number before introduction of prevention. As a causative organism gram-positive bacteria including MRSA were markedly decreased. Major portals of entry of bacteremia (74.9%) were urinary-tract system, intravenous hyperalimentation (IVH) catheter, and pressure sores. MRSA-positive pressure sores were decreased to 20.4% of those before prevention. On the other hand 87 episodes of nosocomial pneumonia were observed before prevention. However a year after introduction of preventive measures episodes of nosocomial pneumonia were decreased to less than a half (44.8%) in comparison to the number before introduction of prevention. After prevention MRSA and mixed infection of P. aeruginosa and MRSA were markedly decreased. The decrease of bacteremia and nosocomial pneumonia were caused by cleaning hands, the preventive measures for decrease and improvement of pressure sores, cleaning the upper respiratory tract for prevention of lower respiratory-tract infection cleaning floors and education of the staff, etc.

[Spontaneous regression of cerebral arterio-venous malformation following major artery thrombosis proximal to dominant feeders: a case report]

A rare case of spontaneous regression of cerebral arterio-venous malformation (AVM) is reported. A 76-year-old male was admitted to Juzen General Hospital due to generalized convulsion on August 24, 1987. On admission, results of physical and neurological examinations were normal. Plain CT scans showed an iso-density lesion with a slightly high density spot in the left frontal lobe, and enhanced CT scans showed multiple, irregularly tubular enhancements in the lesion. Left carotid angiogram (CAG) demonstrated an arteriovenous malformation (AVM) in the left frontal lobe, which was fed by the left ACA and MCA and drained by the ascending cerebral vein and superficial Sylvian vein. There was also an anterior communicating artery aneurysm. At the patient's request, he was treated conservatively and was discharged without neurological deficit. Though he continued to take anticonvulsants thereafter, he felt weakness or numbness of the right extremities once a year. Five years after the first admission, he developed sudden onset of right hemiparesis, aphasia and consciousness disturbance. On admission, his platelet aggregation function was elevated. At this time, enhanced CT scans did not show any enhanced area in the left frontal lobe where AVM had been found previously. T2-weighted magnetic resonance image showed a mixed intensity area without any flow void phenomenon suggesting thrombosis of the nidus. Left CAG demonstrated occlusion of the A1-A2 junction of the anterior cerebral artery and disappearance of the AVM. He was treated conservatively again, and was discharged without neurological deficit.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuronal damage and decrease of central acetylcholine level following permanent occlusion of bilateral common carotid arteries in rat

The neuronal damages and the changes in central acetylcholine (ACh) and choline (Ch) contents following permanent occlusion of bilateral common carotid arteries (2VO) of rats were investigated 1 and 4 months after the operation. Two types of neuronal damages were observed in the rats with permanent 2VO. The first type was the infarctions observed in the cerebral cortex and striatum. The infarction in the cortex and striatum was observed in 28.6 and 42.9% of the animals examined 1 month after permanent 2VO, respectively. These ratios did not change even when examined 4 months after permanent 2VO, suggesting that this type of neuronal damage is due to acute ischemic attacks. The second type was progressive neuronal damages observed in the hippocampus and white matter: the neuronal loss in the CA1 subfield appeared 4 months but not 1 month after permanent 2VO and the rarefaction of white matter which was observed 1 months after permanent 2VO and markedly increased 4 months after the operation. Moreover, ACh level significantly decreased in the striatum but not in the cortex, hippocampus or hypothalamus 1 month after permanent 2VO, while the ACh levels in the cortex, striatum and hypothalamus, and Ch levels in all the regions tested significantly decreased when tested 4 months after the operation. These changes did not accompany necrosis. These results suggest that the progressive neuronal degeneration and cholinergic dysfunction following the permanent 2VO are in part involved in chronic cerebral hypoperfusion-induced long-lasting cognition deficits in rats.

An SV40-immortalized human corneal epithelial cell line and its characterization

PURPOSE

The authors attempted to immortalize human corneal epithelial cells; it is difficult to propagate primary human corneal epithelial cells because of scarcity of available tissue. However, cell immortalization by virus is always accompanied by shedding of free virus. The current study was performed to establish a cell line that produces no free viral particle.

METHODS

Primary cultured human corneal epithelial cells were infected with a recombinant sv40-adenovirus vector and were cloned three times to obtain a continuously growing cell line. Morphologic, cytologic, and biochemical characteristics of this cell line were analyzed.

RESULTS

This cell line continued to grow for more than 400 generations, exhibiting a cobblestone-like appearance similar to normal corneal epithelial cells in culture. Transmission electron microscopy showed the evidence for the characteristic features of epithelial cells, including desmosome formation and development of microvilli. It expressed cornea-specific, 64-kD cytokeratin in addition to five major insoluble proteins. By enzymatic analysis using NADP as a coenzyme and a gas chromatograph mass spectrometer, this cell line was found to possess 8.71 IU/mg protein of aldehydedehydrogenase activity. When this cell line was grown at air-liquid interface on collagen type I gel, it differentiated in a multilayered fashion.

CONCLUSIONS

The authors have established an SV40-immortalized human corneal epithelial cell line with properties similar to normal corneal epithelial cells.

Immunohistochemical properties of malignant mesothelioma cells in histologic and cytologic specimens

Although there is general agreement that immunohistochemical methods can aid in the pathologic diagnosis of malignant mesothelioma, some studies have produced conflicting results. To obtain comparable and reproducible results, unequivocal malignant mesotheliomas were studied with the biotin-streptavidin-peroxidase complex method in 14 formalin-fixed, paraffin-embedded tissue specimens, 5 ethanol-fixed smear slides and 3 cold acetone-fixed smear slides. The expression of CA-125, epithelial membrane antigen (EMA) and vimentin by malignant epithelial mesothelioma cells was hindered by their poor preservation in formalin fixative. Cytologic specimens fixed in cold acetone were the best type for immunohistochemistry. The majority of malignant epithelial mesothelioma cells in the smear slides fixed in cold acetone were positive for CA-125, EMA, low-molecular-weight cytokeratin and vimentin, but none of them were positive for carcinoembryonic antigen, CA-19-9, epithelial antigen, high-molecular-weight cytokeratin or Leu-M1.

Developmental change of kidney dopamine receptors in spontaneously hypertensive rats

To elucidate the role of the kidney dopamine system on blood pressure regulation, we investigated the developmental change of kidney dopamine receptors in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. The autoradiogram of [3H]-SCH23390, a specific DA1 receptor antagonist, showed that DA1 receptors were localized mainly in the rat renal cortex. The radiolabeled receptor assay (RRA) of [3H]-spiperone was performed on 3-, 7-, and 18-week-old SHR using the homogenate of renal cortex. Neither dissociation constant (Kd) nor maximum binding capacity (Bmax) were different between SHR and WKY rats at the age of 3 and 7 weeks. Nevertheless, Kd and Bmax were significantly low in 18-week-old SHR. The systolic blood pressure of 7-, and 18-week-old SHR was significantly higher than that of age matched WKY rats. The urinary dopamine excretion in 16-week-old SHR was significantly higher than that in age-matched WKY rats, although urine volume and urinary sodium excretion were the same as those in the control in both sodium-loaded and -restricted state. In summary, although renal dopamine production was enhanced in SHR in the hypertensive state, dopamine was found not to contribute to natriuresis since the number of dopamine receptors was reduced in these rats. We also found that enhanced dopamine production in response to a salt load was lacking in these rats. These two pathological phenomena noted in the renal dopamine system play a role in the progression of hypertension in SHR.

Clinical and MRI findings in a case of D-2-hydroxyglutaric aciduria

We report the 3rd case in the literature of a 3-year-old boy with D-2-hydroxyglutaric (D-2-HG) aciduria, who presented primarily generalized hypotonia and feeding difficulty during the neonatal period, with eventual development of generalized myoclonic seizures. Gas chromatographic analysis of urinary organic acids showed persistent excretion of D-2-HG. The clinical manifestations are quite similar to those of the 2nd reported case with D-2-HG aciduria. Serial MRI performed 1 year and 2 1/2 years after birth demonstrated bilateral symmetrical periventricular lesions in the parieto-occipital white matter, which might reflect the cortical blindness in our patient.

Regeneration of the tunic cuticle in the compound ascidian, Botrylloides simodensis

The tunic cuticle of Botrylloides simodensis, a colonial ascidian, is an electrondense sheet overlaying the tunic in which zooids are embedded. When the margins of colonies were cut off and the colonies were incubated in running seawater, the tunic cuticle regenerated at the cut surface of the tunic matrix by the following process: 1) Electron-dense fibers appeared at the cut surface within a few minutes. 2) Fiber formation proceeded during the next several hours, and the number of fibers greatly increased. 3) In 12 to 24 hours, the fibers aggregated and formed a continuous layer, which was the newly regenerated cuticle. 4) Minute protrusions appeared in the new cuticle after 3 to 5 days. Fiber formation occurred even in fragments of colonial margins that were incubated in a bottle of seawater. It was inhibited under some experimental conditions including low pH and the presence of some proteases or protease inhibitors.

Unique order of the lymphocyte subset induction in the liver and intestine of mice during Listeria monocytogenes infection

We investigated how NK cells, extrathymic T cells, and thymus-derived T cells are activated in mice during infection with an intracellular pathogen, Listeria (L.) monocytogenes. Although macrophages and granulocytes are known to be involved in the elimination of this pathogen in an early phase of infection, it was still controversial what type of lymphocytes are induced as effectors in subsequent phases. When mice were ip injected with 1 x 10(3) L. monocytogenes (a sublethal dose), a prominent increase in the number of mononuclear cells in the liver and spleen was induced. Phenotypic analysis revealed that serial induction of lymphocyte subsets, NK cells-->extrathymic T cells-->thymus-derived T cells, occurred in these organs. Extrathymic T cells were estimated to have intermediate CD3 and a high level of IL-2 receptor beta-chain on the surface (i.e., intermediate CD3 cells). These mice became free from infection after 2 weeks. In the case of oral administration, 1 x 10(3) L. monocytogenes increased the number of cells in the liver and the number of intraepithelial and lamina propria lymphocytes in the intestine. Phenotypic analysis also showed a sequential induction of lymphocyte subsets in the liver and the induction of extrathymic T cells in the intestine. Preelimination of intermediate TCR cells and NK cells by in vivo treatment with anti-LFA-1 mAb made mice susceptible to an ip injected sublethal dose of L. monocytogenes. These results reveal a unique order of lymphocyte induction during listerial infection and indicate that extrathymic T cells might be one of the important cells in achieving resistance against L. monocytogenes.

Exaggerated messenger RNA expression of inflammatory cytokines in human T-cell lymphotropic virus type I-associated myelopathy

OBJECTIVE

To investigate the expression of inflammatory cytokine messenger RNA (mRNA) in peripheral blood mononuclear cells of patients with human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM).

PATIENTS

Seventeen patients with HAM, 18 HTLV-I-seropositive carriers, and 10 seronegative individuals were studied.

MAIN OUTCOME MEASURE

We compared the expression of tumor necrosis factor alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon alpha (IFN-alpha), IFN-beta, and IFN-gamma, and interleukin 1 alpha (IL-1 alpha) and IL-1 beta by reverse transcriptase-polymerase chain reaction.

RESULTS

In patients with HAM, the reverse transcriptase-polymerase chain reaction products of TNF-alpha, GM-CSF, IFN-gamma, and IL-1 alpha were detected in significantly higher incidences than in HTLV-I-seropositive carriers and seronegative controls. Furthermore, simultaneous mRNA expression of three or more of these four cytokines was detected in all patients with HAM compared with only 21.4% of HTLV-I-seropositive carriers. By contrast, there was no significant difference in mRNA expression of IFN-alpha, IFN-beta, and IL-1 beta among patients with HAM, HTLV-I-seropositive carriers, and HTLV-I-seronegative controls.

CONCLUSIONS

An exaggerated mRNA expression of several inflammatory cytokines, including TNF-alpha, GM-CSF, IFN-gamma, and IL-1 alpha, was demonstrated in peripheral blood mononuclear cells of patients with HAM. Moreover, transcripts of these cytokines were simultaneously up-regulated in patients with HAM, suggesting that an inflammatory state in the central nervous system may be related to the pathogenesis of HAM.

Signal intensity characteristics of mediastinal cystic masses on T1-weighted MRI

OBJECTIVE

We evaluated the intracystic MR signal intensity of mediastinal cystic masses to identify characteristic intensity patterns according to histologic type.

MATERIALS AND METHODS

Magnetic resonance imaging was performed on 26 cystic mediastinal masses consisting of 8 thymic cysts, 5 bronchogenic cysts, 4 pericardial cysts, 5 cystic teratomas, and 4 cystic neurogenic tumors. Signal intensity ratios of each cyst to muscle were calculated on T1-weighted imaging. Surgical records were reviewed to document the presence of intracystic hemorrhage. Chemical analysis of intracystic fluid was performed in three cases.

RESULTS

Bronchogenic cysts, cystic teratomas, and cystic neurogenic tumors had relatively high levels of signal intensities. Each pericardial cyst had a lower signal intensity than muscle. The signal intensities of thymic cysts were variable. Intracystic hemorrhage was present in 1 bronchogenic cyst, 2 cystic neurogenic tumors, 4 cystic teratomas, and 3 thymic cysts. No hemorrhage was found in any of the pericardial cysts. Sebaceous fluid was present in 1 cystic teratoma.

CONCLUSION

The varying intensities of different cysts were considered to reflect the nature of the intracystic fluid. Since the nature of the fluid can reflect the histology to some extent, T1-weighted MRI will help to differentiate cystic mediastinal masses.

Bone formation in vitro and in nude mice by human osteosarcoma cells

Osteosarcomas contain variable amounts of bony tissue, but the mechanism of bone formation by osteosarcoma is not well understood. While a number of cultured human osteosarcoma cell lines have been established, they are maintained by different media and differ qualitatively with regard to bone formation. We examined different media for their ability to support bone formation in vitro and found the alpha-modification of Eagle's minimal essential medium supplemented with beta glycerophosphate was best for this purpose, because it contained the proper calcium and phosphate concentrations. Subsequently, we compared seven human osteosarcoma cell lines under the same experimental conditions to clarify their ability to induce bone formation. NOS-1 cells most frequently exhibited features of bone formation in vitro and in nude mice. Collagen synthesis by tumour cells themselves seemed to be the most important factor for bone volume. However, even HuO9 cells, which lacked collagen synthesis and failed to form bone in vitro, successfully formed tumours containing bone in nude mice. Histological analysis of HuO9 cells in diffusion chambers implanted in nude mice and the findings of polymerase chain reaction indicated that the phenomenon was probably due to bone morphogenetic protein.

Vascularization and innervation of the canine wrist joint synovial membrane

The correlation between vascular distribution and synovial structures was investigated using corrosion cast of the synovial fold of the dog antebrachiocarpal joint (wrist joint) under scanning electron microscopy. Arterial branches arose from a main artery deep in the subsynovial layer, ascended toward the free margin of the fold, dividing into several branches, and finally formed a dense capillary network beneath the lining layer. Immunohistochemical study and a retrograde axonal tracing experiment revealed that almost all nerve fibers were associated with the arterial tree and that: (1) proximal parts of the arterial tree were innervated with neuropeptide Y (NPY)-containing noradrenergic sympathetic fibers, vasoactive intestinal peptide-containing non-catecholaminergic sympathetic fibers from the stellate ganglion and substance P (SP)- and calcitonin gene-related peptide (CGRP)-containing sensory fibers from the C7-T1 segments of the dorsal root ganglia; (2) more distal parts of the arterial branches were associated with NPY-immunoreactive sympathetic fibers and SP- and CGRP-immunoreactive sensory fibers; and (3) the most peripheral precapillary arterioles were accompanied by only SP- and CGRP-containing sensory fibers. These results indicate that synovial blood flow is regulated by at least three different nerve systems which possess regional differences.

Molecular cloning of a cDNA that encodes the precursor to several exogastrula-inducing peptides, epidermal-growth-factor-related polypeptides of the sea urchin Anthocidaris crassispina

Complementary DNA clones for exogastrula-inducing peptides (EGIPs) of the sea urchin Anthocidaris crassispina, which are related to epidermal growth factor (EGF), were obtained from a cDNA library of late gastrula embryos using, as probe, the partial cDNA for one of the EGIP (EGIP-D) obtained by the reverse-transcription PCR method. The longest cDNA was composed of 1662 bp, and encoded a protein of approximately 36 kDa with a region that resembled a signal sequence. The deduced protein contains the sequences of EGIP-C, EGIP-D, and EGIP-A in that order, followed by the sequence for an unidentified EGIP-like polypeptide. When expressed in Escherichia coli as a fusion protein with beta-galactosidase, the product for the cDNA was specifically recognized by a rabbit antibody raised against EGIP-D that had been purified from embryos. Characteristic amino acid residues were found around the N-terminus and the C-terminus of each EGIP sequence, suggesting a specific processing mechanism for the generation of the individual EGIPs from the precursor. RNA-blot analysis revealed the presence of EGIP mRNA in unfertilized eggs. The level of this mRNA decreased gradually after fertilization, began to increase dramatically after the onset of gastrulation, and continued to increase through the pluteus stage. Genomic Southern-blot analysis suggested that this gene is present as a single copy. A homology search showed that the EGIP cDNA has a similarity to the cDNA for SpEGF2 which was cloned as a gastrula-specific gene in another sea urchin, Strongylocentrotus purpuratus.

[Progression of senile aortic valve calcification: echocardiographic and clinical assessment]

Factors involved in the progression of senile aortic valve calcification were evaluated by analyzing the clinical and echocardiographic characteristics of patients older than 69 years with senile aortic valve calcification. The patients were divided into three groups; group 1: 46 male and 40 female patients with calcification of one cusp and almost normal pliability of three cusps, group 2: 48 males and 55 female patients with calcification of two or three cusps, mildly reduced pliability of calcified cusps, and aortic valve area (AVA) > or = 2.0 cm2, group 3: 26 male and 31 female patients with calcification of two or three cusps, significantly reduced pliability of calcified cusps, and AVA < or = 1.5 cm2. There were no significant differences in age, weight, height, left ventricular dimension, or left ventricular wall thickness between these three groups. For male patients, the end-diastolic maximum left ventricular outflow tract dimensions (LVOT) in groups 1, 2, and 3 were 20 +/- 2 mm, 19 +/- 2 mm (p < 0.01 vs group 1), and 17 +/- 3 mm (p < 0.001 vs group 1, p < 0.01 vs group 2), respectively. For female patients, the LVOTs of groups 1, 2, and 3 were 18 +/- 2 mm, 16 +/- 2 mm (p < 0.001 vs group 1), and 16 +/- 2 mm (p < 0.001 vs group 1), respectively. Reduction in LVOT was not associated with left ventricular hypertrophy or decrease in dimension of aortic annulus. In female patients, the frequency of mitral annular calcification of group 3 was 61% [p < 0.05 vs group 1 (35%), p < 0.01 vs group 2 (25%)].(ABSTRACT TRUNCATED AT 250 WORDS)

[Inhibition of induced contraction in the isolated rat mesenteric vascular bed by Ro 40-5967, a novel calcium antagonist]

We designed a study to investigate the effect of the non-dihydropyridine calcium antagonist Ro 40-5967 in the isolated rat mesenteric vascular bed and compared it with that of nifedipine. Ro 40-5967 (10(-6) M) suppressed the KCl-induced contractions, with a potency similar to that of nifedipine (10(-7) M). A bolus injection of norepinephrine and a periarterial nerve stimulation associated with the mesenteric artery increased the perfusion pressure. Ro 40-5967 (10(-6) M) significantly inhibited the contractions induced by norepinephrine and the contractions of the stimulated periarterial nerve in the rat mesenteric arterial bed. In contrast, nifedipine (10(-7) M) did not affect these contractile responses. A subthreshold concentration of endothelin-1 potentiated the contractile responses to norepinephrine and the periarterial nerve stimulation. Ro 40-5967 (10(-6) M) prevented the potentiation of the responses to norepinephrine and the periarterial nerve stimulation evoked by endothelin-1, whereas nifedipine (10(-7) M) did not affect this augmentation. Compared to the effects of nifedipine (10(-7) M), we conclude that Ro 40-5967 (10(-6) M) more effectively prevents the contractions induced by norepinephrine and stimulation of the periarterial nerve and furthermore prevents the amplification of these contractions by endothelin-1. Ro 40-5967 does not seem to block the L-type calcium channel and exerts its effect via some other mechanism.

Noradrenergic denervation attenuates desipramine enhancement of aggressive behavior in isolated mice

The effects of denervation of central noradrenergic system on the desipramine-induced enhancement of aggressive behavior were examined in long-term isolated mice. Consistent with previous reports, desipramine (10 mg/kg, IP) significantly increased the duration of aggressive behavior in isolated mice. Pretreatment of isolated mice with DSP-4, a selective noradrenaline neurotoxin, significantly attenuated the enhancing effect of desipramine on aggressive behavior without affecting the basal aggressive responses. This effect appeared concomitant with decrease of noradrenaline levels in the cortex, hippocampus, cerebellum and hypothalamus (78%, 75%, 57%, and 17%, respectively). DSP-4 did not significantly affect dopamine or 5-HT levels in these regions. These results suggest that noradrenergic terminals originating mainly from the locus coeruleus play an important role in the desipramine enhancement of aggressive behavior, but not in the basal aggressive behavior of isolated mice.