A new enzymatic method for the determination of inulin

A new enzymatic method for the determination of inulin in plasma and urine, using inulase (EC 3.2.1.7), fructokinase (EC 2.7.1.4), phosphoglucoisomerase (EC 5.3.1.9) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) is described. The assay is based on the hydrolysis of inulin or Inutest (INutest which is the injectable form of inulin), by inulase and the determination of fructose released. The assay was linear up to 2 g/L of Inutest. The within-batch and between batch coefficients of variation were 2.3% and 2.2%, respectively. Recovery of added Inutest from plasma and urine was 98-102%. There was no interference from glucose (27.7 mmol/L), fructose (1.7 mmol/L) or mannose (1.7 mmol/L). When inulin clearance (using this method) and thiosulphate clearance were compared in 37 patients the inulin clearance was 9.3 mL/min (12%) lower than the thiosulphate clearance. We conclude that this enzymatic method is a simple and specific method.

Long-term spatial cognitive impairment after middle cerebral artery occlusion in rats: no involvement of the hippocampus

The behavioral and neurochemical changes in the chronic phase of permanent occlusion of the right middle cerebral artery (MCA) in rats were investigated. One month after MCA occlusion, 23 rats were unable to solve a radial eight-arm maze task during an entire 1-month period, whereas seven rats were able to solve this task. Three months after occlusion, 19 MCA-occluded rats failed to solve the task successfully again for at least 1 month (the cognitively impaired rats), whereas 11 MCA-occluded rats were able to solve it (the cognitively unimpaired rats). The rats that underwent behavioral testing were examined for any changes in the acetylcholine (ACh) levels in the hippocampus using HPLC with electrochemical detection or the formation of long-term potentiation (LTP) in the population spike of the hippocampal CA1 field. The immunohistochemical distribution of either the microtubule-associated protein 2 (MAP2) or glial fibrillary acidic protein (GFAP) in the hippocampus of the cognitively impaired rats was also studied. In the cognitively impaired rats, neither the suppression of the induction of LTP, nor the degradation of MAP2, nor the increase in the GFAP immunoreactivity was observed in the hippocampus. The levels of ACh in the hippocampus did not change significantly among the cognitively impaired, unimpaired, and the sham-operated rats. These results suggest that MCA occlusion is capable of producing long-term spatial cognitive disturbance in rats without any evidence of neurobiological damage in the hippocampus.

Reduction of left ventricular hypertrophy with St. Jude Medical 19 mm valve prosthesis

To determine the permissible range of the St. Jude Medical 19 mm valve (SJM19) as an aortic prosthesis, transvalvular maximal pressure gradient (maxPG) and postoperative reduction of left ventricular (LV) hypertrophy were examined in 21 patients (body surface area [BSA] 1.28-1.56 m2, mean 1.42 m2). Doppler echocardiographically measured maxPG at rest was 31 +/- 16 mmHg, which showed no significant difference from the differences in patients' diseases (aortic regurgitation = AR or stenosis = AS), or BSA. The maxPG, also measured during dobutamine administration when they were less than 40 mmHg at rest, increased significantly from 21 +/- 11 mmHg to 32.1 +/- 15 mmHg, having no differences from the differences in diseases or BSA. Reduction of LV hypertrophy was achieved postoperatively (mean postoperative period of ten months), with the reduction rates of 26 +/- 19% in LV mass and 21 +/- 15% in LV cross-sectional area. No significant differences were found between the reduction rates and the differences in the patients' diseases or BSA. These results indicate that, following the implantation of SJM19, LV hypertrophy was reduced in patients with AR as well as with AS, when their BSA values were less than 1.6 m2. However, limited use is recommended because the increase in pressure gradient during exercise cannot be ignored.

Long-term follow-up study of Crohn's disease in Japan. The Research Committee of Inflammatory Bowel Disease in Japan

Two hundred and three patients with Crohn's disease seen at Kyushu University, Fukuoka University, and their affiliated centers from 1973 to 1988 were followed for 4.4 +/- 3.2 years (mean +/- SD), to evaluate the prognosis relative to life span and surgery. Cumulative survival rate and cumulative operation rate were calculated by the life table method. Cumulative survival rates 5 and 10 years after diagnosis were 98.9% and 98.9%, respectively; these figures were not different from the expected survival rates in the sex-and age-matched general population. Cumulative operation rates 5 and 10 years after the onset of symptoms were 16.2% and 39.1%, respectively, In a second study, we investigated 419 patients with Crohn's disease, diagnosed at nine institutions from 1975 to 1990. The follow-up period was 6.3 +/- 3.9 years and the information was obtained from mailed questionnaires. Cumulative survival rates 5 and 10 years after diagnosis were 99.2% and 96.9%, respectively. Cumulative operation rates 5 and 10 years after the onset of symptoms were 30.3% and 70.8%, respectively. These results indicate that the prognosis of Japanese patients with Crohn's disease may be superior to that reported in Western countries.

Mutations of the p53 gene in myelodysplastic syndrome and overt leukemia

We analysed p53 mutations in 24 patients with myelodysplastic syndrome (MDS) and overt acute myeloid leukaemia after a period of MDS, using polymerase chain reaction-single strand conformation polymorphism analysis. In exons 5 to 8, mobility shifts were detected in five of the 24 patients. Sequence analysis was subsequently performed, and four missense mutations (16.7%) and one silent nucleotide substitution were identified. Patients harbouring mutations were characterized as having advanced disease. Loss of the wild type allele was observed in three of the four patients with missense mutations. No mobility shifts of the N-ras or FMS gene were detected in these four patients. We next analysed the correlation of the p53 mutations with the progression of MDS in three patients. The mutation was accompanied by the progression in two of the three patients. These findings suggest that mutations of the p53 gene are associated with progression in some cases of MDS, while being compatible with stable disease or clonal evolution in others.

Reduced cell motility and enhanced focal adhesion contact formation in cells from FAK-deficient mice

The intracellular protein tyrosine kinase FAK (focal adhesion kinase) was originally identified gy its high level of tyrosine phosphorylation in v-src-transformed cells. FAK is also highly phosphorylated during early development. In cultured cells it is localized to focal adhesion contacts and becomes phosphorylated and activated in response to integrin-mediated binding of cells to the extracellular matrix, suggesting an important role in cell adhesion and/or migration. We have generated FAK-deficient mice by gene targeting to examine the role of FAK during development. Mutant embryos displayed a general defect of mesoderm development, and cells from these embryos had reduced mobility in vitro. Surprisingly, the number of focal adhesions was increased in FAK-deficient cells, suggesting that FAK may be involved in the turnover of focal adhesion contacts during cell migration.

Synthesis of 2(1H)-quinolinone derivatives and their inhibitory activity on the release of 12(S)-hydroxyeicosatetraenoic acid (12-HETE) from platelets

A search for potent inhibitors of release of 12(S)-hydroxyeicosatetraenoic acid (12-HETE), which plays an important role in the pathogenesis of various circulatory disorders and arteriosclerosis, led us to 6-[4-(1-cyclohexyl-5-tetrazolyl)butoxy]-3,4-dihydro-2(1H)-quinolinone (cilostazol) and 2(1H)-quinolinone derivatives having an azole group in the side chain. Many 2(1H)-quinolinone derivatives were synthesized and tested in vitro for the inhibitory activity in human platelets. 3,4-Dihydro-6-[3-(1-o-tolylimidazol-2-yl)sulfinylpropoxy]-2( 1H)-quinolinone (5k) was found to be one of the most potent inhibitors of 12-HETE release, being more potent than esculetin. In addition, the sulfoxide 5k showed in vivo inhibitory activity on platelet adhesion in rats. Since 5k is racemic, the enantiomers were prepared and their potencies were compared in vitro and in vivo. (S)-(+)-5k had the best pharmacological profile and was selected as a candidate drug for further development. The structure-activity relationships are discussed.

17 alpha-Hydroxyprogesterone suppresses neovascularization induced by HPLC-purified ovarian hyaluronic acid-like glycosaminoglycan in mice

HPLC-purified glycosaminoglycans (hpGAG) prepared from extracts of non-luteal mouse (JcL:ICR strain) ovaries were assayed for neovascularization by implanting Elvax films, containing test samples, on the lateral wall of the sheath of m. rectus abdominis in adult female mice of the same strain. Neovascularization occurred in a dose-dependent manner, and was characterized by capillary outgrowth extending into the tissue surrounding the implant. The single major peak of purified GAG on a column of TSK gel DEAE got out of order after treatment with streptococcal hyaluronidase or nitrous acid. The activity of this fraction was also greatly reduced when treated with streptococcal hyaluronidase or nitrous acid. When hpGAG was embedded in the implant with 17 alpha-hydroxyprogesterone at a dose of 20 micrograms/film, neovascularization induced by means of hpGAGs was suppressed. Progesterone at a dose of 50 micrograms/film did not suppress the neovascularization induced by ovarian hpGAG. These findings suggest that 17 alpha-hydroxyprogesterone suppresses the angiogenic activity of hyaluronic acid-like hpGAG in the ovary.

Evaluation of disease activity in patients with moderately active ulcerative colitis: comparisons between a new activity index and Truelove and Witts' classification

OBJECTIVES

We have recently proposed a new activity index (AI) for ulcerative colitis. The aim of this study was to examine how AI would reflect the effect of medical therapy in comparison with Truelove and Witts' criteria.

METHODS

In this trial, we studied 35 patients with extensive colitis who persisted with moderate disease for 2 wk. They showed no change in disease activity according to Truelove and Witts' classification despite 2 wk of corticosteroid therapy. Nine of the 35 patients underwent surgery (operated group), and 26 responded to the medical therapy and went into remission (nonoperated group).

RESULTS

In the nonoperated group, AI values significantly decreased at 1 and 2 wk after treatment compared with pretreatment values, whereas there was no significant change in AI in the operated group during the clinical course. Remission occurred in all patients indicating below 180 of AI values 2 wk after therapy, whereas approximately 65% of patients indicating above 180 of AI values subsequently needed colectomy.

CONCLUSIONS

This study suggests that AI will be useful in evaluation of response to medical therapy and prediction of remission and colectomy in patients with moderately active ulcerative colitis.

Effects of a selective endothelin A-receptor antagonist, BQ-123, in salt-loaded stroke-prone spontaneously hypertensive rats

1. We examined the effects of a selective endothelin A (ETA)-receptor antagonist, BQ-123, on the development of hypertension and organ damage in stroke-prone spontaneously hypertensive rats (SHRSP) given 1% NaCl for 6 weeks. 2. BQ-123 at doses of 0.7, 2.1 and 7.1 mg/day was continuously administered for 6 weeks to 8 week old salt-loaded SHRSP, who were given water containing 1% NaCl for the following 6 weeks, via a subcutaneous osmotic minipump. 3. Development of high blood pressure was accelerated in salt-loaded SHRSP compared with that in non-salt-loaded SHRSP. After 6 weeks of salt-loading, incidence of cerebral infarction, renal sclerosis and renal fibrosis were greater in salt-loaded than non-salt-loaded SHRSP. 4. BQ-123 attenuated the age-related rise in blood pressure in a dose-dependent manner. The effect coincided with reduction in the incidence of cerebral infarction and prevention of renal sclerosis and fibrosis. Kidney function was improved as observed by an increase in glomerular filtration rate and decreases in urinary protein excretion, blood urea nitrogen and fractional sodium excretion. Furthermore, BQ-123 prevented increases in the heart weight/bodyweight ratio and aortic wall thickness in salt-loaded SHRSP. 5. These results suggest that endogenous endothelin-1 (ET-1) and ETA-receptors may be, at least in part, involved in the pathogenesis of hypertension and organ damage in salt-loaded SHRSP.

Quantitative analysis of synaptogenesis in the inner plexiform layer of macaque monkey fovea

Synaptogenesis has been tracked by using quantitative electron microscopic methods in the inner plexiform layer (IPL) of the developing Macaca monkey fovea from fetal day (Fd) 55 to Fd132. Vesicle-containing profiles were classified according to whether (1) they contained a ribbon indicating that they originated from a bipolar cell, or (2) the profile formed a junction. Group 2 was further subdivided by morphological characteristics into (2a) amacrine, (2b) bipolar, or (2c) unknown profiles. Ribbon-containing bipolar profiles are clearly identifiable at Fd55 when they occur at a density of 0.9/100 microns2. Bipolar synapses increase rapidly to 4.7/100 microns2 by Fd88, similar to their density at Fd132. Identifiable amacrine profiles forming a junction are rare at Fd55-68. By Fd88, amacrine synaptic density has jumped to 6.7/100 microns2 and continues to increase to 9.5/100 microns2 at Fd132. These quantitative data strongly suggest that, at the Macaca fovea, bipolar synaptogenesis both begins and ends before amacrine synaptogenesis. The large number of immature amacrine synaptic profiles and densities at Fd132 suggests that amacrine synapses continue to form after Fd132. This study confirms that cone-dominated monkey fovea has a different sequence of synaptogenesis than the rod-dominated peripheral retina (Nishimura and Rakic, [1985] J. Comp. Neurol 241:420-434). The data support the concept that synaptic developmental sequence is determined by the type of photoreceptor which dominates a particular retinal region or species. Bipolar ribbon synapses are observed in the outer half of the IPL at Fd55, are present in the inner IPL at Fd60, and then, with increasing age, are found throughout the IPL. This pattern strongly suggests that vertical OFF bipolar pathways form earlier than ON pathways in the IPL. In contrast, amacrine profiles are found throughout the IPL at the youngest ages, with an adult-like banding pattern present by Fd132.

Sutureless anastomosis using a biofragmentable anastomosis ring

The biofragmentable anastomosis ring (BAR) is composed of polyglycolic acid and barium sulfate. When used for intestinal anastomosis, the BAR fragments after the anastomosis is established. We used this device in 43 patients. In three patients, the anastomosis with BAR was abandoned due to technical difficulties. A total of 43 anastomoses with BAR were performed in 40 patients. The operations in which BAR was used included right hemicolectomy in 12 patients, transverse colectomy in 7, sigmoidectomy in 11, small bowel resection in 5 and other bowel resections in 8. The time spent for the BAR anastomsis ranged from 7 to 30 min with a mean of 15.2 min, which was significantly shorter than that of conventional hand-sutured anastomosis in 23 cases. The fragmentation and excretion of the BAR occurred from 14 to 49 days later with a mean of 21.8 days. There was only one instance of anastomotic leakage (1/40, 2.5%), which occurred in a patient with a cytomegaloviral infection of the intestine. A postoperative barium enema study in 28 patients showed no passage disturbance through the anastomosis. In conclusion, the anastomosis using BAR is considered to be a simple, safe, and fast method for performing either colonic or small intestinal anastomosis.

Lithium addition to neuroleptic treatment in chronic schizophrenia: a randomized, double-blind, placebo-controlled, cross-over study

We studied the effect of lithium addition to neuroleptic treatment in chronic schizophrenia, for which contradictory results have been produced in previous studies. Twenty-one chronic schizophrenic inpatients received lithium in a study with randomized, double-blind, placebo-controlled, cross-over design consisting of 8 weeks each of treatment with lithium capsules and identical placebo capsules. The total Brief Psychiatric Rating Scale (BPRS) scores at week 8 of the lithium treatment were improved significantly compared with those at week 8 of the placebo treatment. Of the BPRS subscales, however, only anxiety-depression improved, whereas none of the subscales for anergia, thought disturbance, activation and hostile-suspiciousness improved. There was no significant difference between the total Scale for the Assessment of Negative Symptoms (SANS) scores at any time during lithium and placebo treatment. These results suggest that the addition of lithium to neuroleptic treatment improves anxiety-depression in chronic schizophrenia.

Contrasting baroreflex effects of muscimol versus bicuculline injected into the nucleus tractus solitarius in anesthetized rats

To examine how the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) affects baroreflex regulation, reflex heart rate and renal nerve responses were recorded in anesthetized rats after bilateral injections of muscimol or bicuculline into the nucleus tractus solitarius (NTS). Blood pressure, heart rate, and renal nerve activity were increased by the GABA agonist muscimol and decreased by the GABA antagonist bicuculline. Control injections of the vehicle alone were ineffective. More importantly, all reflex responses later induced by infusing phenylephrine or sodium nitroprusside intravenously were reduced by muscimol. The magnitude of the reflex bradycardia and sympathoinhibition caused by phenylephrine, as well as that of the reflex tachycardia and sympathoexcitation caused by sodium nitroprusside, diminished after NTS injections of muscimol. By contrast, the same reflex responses tended to be enhanced after NTS injections of bicuculline, but most changes were not significant. If GABA acts on receptors located on second-order neurons in the NTS, then muscimol would inhibit those neurons, whereas bicuculline would prevent endogenous GABA from reaching them. Thus muscimol would reduce reflex responsiveness by inhibiting all second-order neurons, whereas bicuculline would enhance it by protecting the same neurons from inhibition by endogenous GABA.

Nucleotide sequence of a principal sigma factor gene (hrdB) of Streptomyces griseus

The hrdB homologue was isolated from a streptomycin-producing Streptomyces griseus 2247 strain, which is independent of A-factor. The nucleotide sequence of the cloned DNA fragment revealed the presence of an open reading frame (ORF) of 1,542bp, which predicted a primary product of 514 amino acids and Mr 56,100. The N-terminal sequence of the purified HrdB protein of S. griseus was identical to the amino acid sequence deduced from the nucleotide sequence. The deduced amino acid sequence contains an "rpoD box" conserved in the principal sigma factors of eubacteria, and shows high similarity to the hrdB products of S. coelicolor A3(2)(89.9%) and S. aureofaciens (88.1%). The cloned gene encodes a principal sigma factor of S. griseus. The promoter region was identified by using a promoter-probe vector and by means of primer extensions experiments. The transcription start point is located 158-bp upstream of the initiation codon.

The potent and selective inhibition of estrogen production by non-steroidal aromatase inhibitor, YM511

YM511 inhibited aromatase activities in microsomes from rat ovary and human placenta competitively (IC50s: 0.4 and 0.12 nM, respectively). YM511 was about 3 times more potent than other aromatase inhibitors, such as CGS 16949A, CGS 20267 and R 76713. YM511 decreased the contents of estradiol stimulated by pregnant mare's serum gonadotropin in rat ovary with an ED50 of 0.002 mg/kg, indicating that YM511 was equipotent to CGS 20267 and 3 times more potent than the other two inhibitors. Serum estradiol levels in female rats were reduced by YM511 at 0.01 mg/kg into the ovariectomized range. YM511 at 1 mg/kg for 2 weeks decreased rat uterine weight to levels comparable to ovariectomy, showing it was 10 times more potent than other inhibitors. But the maximal inhibitory effect of tamoxifen failed to reach ovariectomized level. YM511 slightly inhibited production of other steroid hormones in vitro and in vivo. The IC50s of YM511 for aldosterone and cortisol production from adrenal cells were from 5500 to 9800 times higher than that for rat ovarian aromatase and 130,000 times higher for testosterone production, indicating that YM511 is a highly specific aromatase inhibitor. The data suggest that YM511 may be a potent and selective agent for suppressing estrogen-dependent action without affecting serum levels of other steroid hormones.

A human monoclonal antibody to a human self-antigen, CD2 derived from human peripheral blood lymphocytes engrafted in SCID mice

To establish human hybridoma lines, production of human immunoglobulin (Ig) and behavior of the implanted human peripheral blood lymphocytes (PBL) were characterized in severe combined immunodeficiency (SCID) mice. Human PBL from healthy donors were injected into the peritoneal cavity of SCID mice, and they were immunized with self-antigen, CD2. CD45+ cells (human PBL) migrated to lymphoid tissues in the mice as early as 4 days, accounting for more than half the lymph node cells and thymocytes. The number of cells releasing human IgG specific to the antigen increased 3.5 weeks after immunization without the usual constraint that production of the IgG, an autoantibody, is prohibited by immunological tolerance in humans. Therefore, we established several human hybridomas secreting human IgG to CD2, since splenocytes and lymph node cells from the implanted SCID mice at 3.5 weeks were fused with a human B lymphoblastoid cell line. A human anti-CD2 monoclonal antibody (MAb) was confirmed to bind to natural CD2 on human T cells by flow cytometric analysis. The epitope for the MAb was identical with a portion that the ligand LFA-3 binded, so that the MAb might reduce the inflammatory reaction caused by preventing activation of human T cells. Here, we report that the human immune system could be reconstituted in SCID mice to develop human hybridomas producing human MAb to a human self-antigen.

[A case of papillary muscle rupture associated with acute inferior myocardial infarction]

A sixty-year-old man was admitted to our hospital due to prolonged left anterior chest oppression and hypotention. The electrocardiogram revealed acute inferior myocardial infarction, confirmed by the coronary angiography which showed occluded right coronary artery (RCA) at the segment 4AV. The intra-coronary pro-urokinase infusion and coronary angioplasty successfully revascularized the occluded 4AV segment. Although the 4AV segment perfused small area, he developed severe pulmonary edema on the second hospital day. A transesophageal echocardiography revealed severe mitral regurgitation due to posterior mitral valve prolapse by the ruptured tendineae with a mobile mass. The damaged mitral valve was replaced by the prosthetic mechanical valve (SJM 25M), resulted in stable hemodynamic state. He discharged one month after the operation.

Dopaminergic system mediation of stimulatory effect of melatonin on secretion of prolactin

OBJECTIVE

The purpose of the present study was to clarify the mechanism of the stimulatory effect of melatonin on the secretion of prolactin.

METHODS

Determination was made of the levels of dopamine (DA), 3,4-dihydroxyphenlacetic acid (DOPAC), serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) in the median eminence of rats following intravenous melatonin (100 micrograms) administration.

RESULTS

Administration of 100 micrograms of melatonin to rats resulted in a significant increase in prolactin secretion (p < 0.01, analysis of variance). Administration of melatonin also resulted in significant decreases in the DOPAC content (p < 0.05) and in the DOPAC/DA ratio (p , 0.05) in the median eminence 1 hour after melatonin administration, at which time serum prolactin was maximal. However, no significant changes were detected in the content of 5-HT or 5-HIAA or in the 5-HIAA/5-HT ratio in the median eminence.

CONCLUSION

These results suggest that the stimulatory effect of melatonin on the secretion of prolactin might be mediated by dopaminergic mechanisms.

Genomic organization and isoforms of the mouse ELP gene

Analysis was made on the genomic structure, functions, and expression of the mouse ELP gene, which codes for the embryonal long terminal repeat binding protein. Extensive screening of the cDNA library of embryonal carcinoma cells (EC cells) identified four isoforms of ELP: ELP1 (the original ELP isolate), ELP2, ELP3, and Ad4BP/SF1. Analysis of the genomic sequences revealed that these ELP isoforms were generated by alternative promoter usage and differential splicing. The mRNAs of isoforms initiated at four transcription start sites distributed on three exons. Sequence analysis of the four isoforms identified three polypeptides. The N-terminal portion of ELP1 and ELP2 was longer than ELP3, and Ad4BP/SF1 by 77 aa. The DNA-binding domain and region II were shared by all four isoforms. The C-terminal portion shared by ELP2, ELP3, and Ad4BP/SF1 was 131 aa in length, and that specific to ELP1 was 57 aa in length. The ELP3 and Ad4BP/SF1 isoforms were identical for the coding sequence, but the two differed at the 5' noncoding region. Region II and III domains of nuclear receptors were thought to be involved in ligand-binding and transcriptional activation. ELP1, which lacked region III, functioned as a repressor. The isoforms carrying intact region II and region III functioned as transactivators. Expression of the four isoforms was studied in mouse tissues and in tissue culture cells by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Complex patterns of expression of these isoforms were observed in various tissues. All four ELP isoforms were expressed only in EC cells.

Establishment of canine pulmonary hypertension with dehydromonocrotaline. Importance of larger animal model for lung transplantation

Single lung isografting in rats with pulmonary hypertension has been reported. However, it is hard to evaluate cardiopulmonary hemodynamics accurately or to use circulatory assists during procedures using rats. Therefore, we tried to establish a model of pulmonary hypertension in the beagle. Twenty young beagles were randomized into 3 groups. An injection of dehydromonocrotaline of 1.5 mg/kg (group 1, n = 7), 3.0 mg/kg (group 2, n = 10), or 4.5 mg/kg (group 3, n = 3) was performed via the right atrium. Two dogs in group 2 and all the dogs in group 3 died of acute pulmonary edema. During the 8 weeks after injection, the systolic pulmonary arterial pressure and pulmonary vascular resistance index increased significantly in group 2 from 21 +/- 2 to 56 +/- 9 mmHg and from 106 +/- 39 to 826 +/- 176 dynes.sec.cm-5.m2, respectively (P < 0.01). The changes in group 1 were less pronounced. The dogs in group 2 also had a rise in their plasma endothelin-1. Pathologic analysis revealed thickening of the media in small pulmonary arteries and hypertrophy of the right ventricular myocardium. Our data indicate that beagles treated with 3.0 mg/kg dehydromonocrotaline produced a unique, relatively noninvasive model of pulmonary hypertension. In the model, right ventricular failure prevented us from clamping one pulmonary artery. These relatively large animals with pulmonary hypertension will be valuable for further studies of lung transplantation.

Acute left atrial thrombus causing cardiogenic shock following mitral valve replacement: report of a case

We report herein the rare case of a 53-year-old woman who developed cardiogenic shock due to an acute left atrial thrombus following replacement of the mitral valve. A definitive diagnosis was not able to be made using precordial echocardiography because of the broad, flat shape of the thrombus; however, transesophageal echocardiography imaged the thrombus in detail. The patient was initially stabilized by percutaneous cardiopulmonary support after which a thrombectomy was successfully performed.

Correlation between anti-ubiquitin immunoreactivity and region-specific neuronal death in N-methyl-D-aspartate-treated rat hippocampal organotypic cultures

Neuronal degeneration appears to be associated with changes in anti-ubiquitin immunoreactivity (UIR). To elucidate the relationship between the two events, we examined the time course of changes in UIR in pyramidal neurons of hippocampal organotypic cultures following exposure to an excitotoxin, N-methyl-D-aspartate (NMDA). In nontreated cultures, weak UIR was confined to the nucleus. Exposure to 100 microM NMDA for 15 min induced degeneration of pyramidal neurons, within 24 h, in the CA1 and CA3c regions. In these neurons, the nuclear UIR was reduced, and instead, UIR developed in the cytoplasm. In response to the same procedure, CA3a,b pyramidal neurons showed slight shrinkage but otherwise virtually normal morphological features. Little perikaryal (cytoplasmic) UIR developed in CA3a,b neurons. Both degeneration and perikaryal UIR were observed in CA3a,b neurons, however, when the culture was exposed to 300 microM NMDA. Immunoblot analysis showed that changes in the amount of a ubiquitin protein conjugate (24 kDa), presumably ubiquitinated histone, are similar to those of nuclear UIR in the same time course. We propose that the changes in the expression of nuclear and perikaryal ubiquitinated proteins represent some process closely related to neuronal death.