Intravascular treatment of spinal arteriovenous malformations using a microcatheter--with special reference to serial xylocaine tests and intravascular pressure monitoring

Spinal arteriovenous malformations (spinal AVMs) are now treated using microcatheters and various embolic materials. Interventional techniques of this type are thought to be the first choice for treatment of spinal AVMs. In this study, we used the Tracker vascular access system and MAGIC catheter for intravascular treatment of spinal AVMs in order to avoid proximal occlusion. Notably, serial provocation tests using xylocaine (20 mg in bolus) and intermittent intravascular pressure monitoring in the anterior spinal artery were conducted during embolizations of five intramedullary AVMs. We used 150-350 microns polyvinyl alcohol particles (Ivalon) and/or polyvinyl alcohol (PVA) solutions as embolic materials for occlusion of these AVMs. Vital signs and neurologic functions were carefully monitored during and after the procedure. We were able totally to obliterate the nidus or markedly to reduce its size while preserving the anterior spinal artery in each of the patients. The xylocaine test was conducted an average of 2.6 times (2-4 times) during embolization. For the two patients who were treated with Ivalon and PVA solutions, the final provocation test became positive, and the embolization procedure was terminated. On the other hand, the remaining patients had a positive result on first xylocaine test and were treated with Ivalon alone. At the same time, intravascular pressure monitoring was performed via the microcatheter, which was located in the anterior spinal artery. The value of the intravascular systolic pressure prior to embolization was 71.6 +/- 14.1 mm Hg and it gradually increased during the procedure, and reached 99.6 +/- 12.6 mm Hg (90% of the systemic systolic blood pressure) by the conclusion of embolization. Serial xylocaine tests and intravascular pressure monitoring may be useful for the treatment of spinal AVMs fed mainly by the anterior spinal artery, and embolization with liquid embolic material should be terminated when the provocation test becomes positive and intravascular pressure increased to 90% of the systemic blood pressure.

Urinary kallikrein activity is increased during the first few weeks of exercise training in essential hypertension

OBJECTIVE

To determine whether the renal kallikrein-kinin and dopamine systems participate in lowering blood pressure during mild exercise in hypertensives.

DESIGN

After a general clinical observation period of 4 weeks, 27 essential hypertensives were divided into two groups. The exercise group underwent blood lactate threshold exercise, using a cycle ergometer for 60 min three times a week for 10 weeks. The non-exercise group was observed at the outpatient clinic. Blood pressure and humoral parameters were measured at weeks 0, 1, 2, 4 and 10 in both groups.

METHODS

Blood pressure was measured indirectly with an automatic blood pressure recorder. Twenty-four-hour urinary kallikrein activity (by kininogenase assay), total or free dopamine and total noradrenaline (by high-performance liquid chromatography) were also measured.

RESULTS

In the non-exercise group blood pressure and humoral parameters did not change. In the exercise group the change in resting blood pressure between weeks 0 and 10 was statistically significant. The change in 24-h urinary kallikrein activity of the exercise group was significantly greater than that of the non-exercise group between weeks 0 and 1 and weeks 0 and 2. Moreover, the change in systolic blood pressure (SBP) between weeks 0 and 2 was negatively correlated with the change in urinary kallikrein activity between weeks 0 and 2, the change in total dopamine between weeks 0 and 2 was negatively correlated with the change in diastolic blood pressure in the same period, and the change in SBP between weeks 0 and 10 was positively correlated with the change in total noradrenaline in the same period in the exercise group. Subjects with a relatively high baseline urinary kallikrein activity had a significantly greater change in SBP between weeks 0 and 10 than subjects with a relatively low baseline activity.

CONCLUSIONS

The renal kallikrein-kinin and dopamine systems may participate in lowering blood pressure during the first few weeks of exercise training. The subsequent reduction of sympathetic activity may be involved in maintaining the lowered blood pressure. Mild exercise is more effective in reducing blood pressure in hypertensives who have a relatively high basal renal kallikrein-kinin system activity.

Analysis of cytoplasmic and surface antigens in childhood T-cell acute lymphoblastic leukaemias: clinical relevance of cytoplasmic TCR beta chain expression

Expression of surface and cytoplasmic antigens on the blasts from 42 cases of childhood T-cell acute lymphoblastic leukaemia (T-ALL) were analysed. All with childhood T-ALL, except for one case expressing cytoplasmic TCR delta chain, were classified on the basis of differential expression of cytoplasmic CD3 (cCD3), TCR beta chain (cTCR beta) and surface CD3 (sCD3) into the following three groups: group I (cCD3+, cTCR beta-, sCD3-), eight cases (19.5%); group II (cCD3+, cTCR beta +, sCD3-), 23 cases (56.1%); group III (cCD3+, cTCR beta +/-, sCD3+), 10 cases (24.4%). Each group defines the stepwise maturational stage of the CD3/TCR complex along the intrathymic T-cell differentiation. Group I had the lowest initial WBC count among the three groups (P < 0.05) and showed significantly (P < 0.05) a higher event-free survival (0.75) than those of group II (0.33). There was no significant difference in both the initial WBC count and the event-free survival between groups II and III. Thus, the absence of cTCR beta in sCD3-negative T-ALL appears to be a good prognostic factor, suggesting that this classification provides a useful tool to predict the prognosis of childhood T-ALL. This is the first report, to our knowledge, studying the relationship between the expression of cytoplasmic CD3/TCR antigens and the clinical features in T-ALL.

[MRI imaging of purulent cerebral ventriculitis]

This report concerns a 68-year-old male who was diagnosed as having purulent ventriculitis based on CT and MRI findings. He was first admitted to a nearby hospital with fever and impaired consciousness and thought to be suffering from herpes simplex encephalitis based on laboratory findings. In spite of treatment with acyclovir and antibiotics, his symptoms persisted for one and a half months. Because of gradual deterioration of his neurological status, he was transferred to our hospital. On admission he was stuporous with nuchal rigidity and a fever of 38.5 degrees C. The CSF leukocyte count was elevated (217/mm3) with predominantly polymorphonuclear cells (mononuclear 20, polymorphonuclear 197). Gd-DTPA MRI (T1-weighted) showed marked enhancement of the ependyma of the fourth ventricle and both lateral ventricles. A diagnosis of purulent ventriculitis was made and high-dose antibiotics (ABPC 12g, CTX 9g) were started intravenously. Gradual improvement in the clinical signs was observed with rapid normalization of the CSF cell-count. The patient had completely recovered one month after the start of treatment and this was associated with disappearance of abnormal enhancement on the MRI images. Although cerebral ventriculitis occasionally occurs as a complication of neonatal meningitis, it is rare in adult purulent meningitis. In our patient, persistent meningitis combined with impaired drainage of CSF from the ventricles are presumed to have caused ventriculitis. Serial enhanced MRI is particularly helpful in diagnosing ventriculitis, and can serve as a good index for monitoring the effects of treatment.

Ethylene vinylacetate copolymer particles dissolved in polyvinyl alcohol (2,000-mer) solution as an embolic material for vascular anomalies. A preliminary study

We have prepared a new material for embolisation: ethylene vinylacetate copolymer dissolved in polyvinyl alcohol. When in contact with blood, polyvinyl alcohol rapidly becomes a soft gel, which is accompanied by wedging of the ethylene vinylacetate copolymer. We analysed the histopathology of intra-arterial microemboli in rats, after intracarotid injection of this material. We confirmed that it was applicable to embolisation for neurosurgical treatment.

Percutaneous transluminal angioplasty of internal carotid artery: a preliminary report of seesaw balloon technique

Percutaneous transluminal angioplasty (PTA) has become a common neurosurgical procedure. This technique, however, has been rarely used for stenosis of the internal carotid artery because of the resultant embolization with debris following balloon manipulation. We present a case of internal carotid artery stenosis with a complaint of transient mono-ocular blindedness, whose ischaemic attack was relieved by PTA operation. In this case, we applied endovascular treatment for carotid stenosis, known as 'seesaw balloon technique', which prevented cerebral embolization with debris from the lesion. This technique may simplify the endovascular treatment for distally located carotid stenosis and shorten the operation time.

Epstein-Barr virus-infected T lymphocytes in Epstein-Barr virus-associated hemophagocytic syndrome

The clonal composition of EBV-infected cells was examined in three cases of EBV-associated hemophagocytic syndrome by analysis of the heterogeneity of terminal repetitive sequences in the EBV genome, indicating monoclonal expansion of EBV-infected cells in all cases. Involvement of T lymphoid cells was determined by in situ hybridization using 35S-labeled RNA probes specific for the small EBV-encoded nuclear RNAs, EBER1 and EBER2, in combination with immunostaining for the TCR-beta chain, CD45RO, CD20, CD30 and CD68 antigens in these three cases. The majority of lymphoid cells showing EBER transcripts were stained by antibodies against CD45RO and T cell receptor-beta. In contrast, EBER-specific signals were not detectable on B cells or hemophagocytic cells. These data support the concept that EBV-associated T cell proliferation is a primary feature of EBV-AHS.

[A case of bronchial lipoma treated by Nd-YAG laser surgery]

A 59-year-old man was referred to our hospital with complaint of cough. On physical examination the patient was 159 cm tall and weighted 68 kg. Chest X-ray showed an infiltrative shadow in the left lower lung field. Bronchoscopic findings revealed a polypoid tumor with smooth surface, located at the lower part of the left main bronchus and occupying over two-thirds of the left basal bronchus. A hamartoma was suspected as the result of bronchial biopsy. Endoscopic Nd-YAG laser surgery was performed. The left basal bronchus was opened. Histologically the tumor consisted mainly of mature fat tissue with collagen fibers and was diagnosed as a bronchial lipoma. Bronchial lipoma arising from the submucosal tissue of a large bronchus, occurs mainly in obese and middle-aged men. It is a rare benign tumor of the lung and only 38 cases have been reported in Japan.

Analysis of the target cell for Epstein-Barr virus infection in Epstein-Barr virus associated hemophagocytic syndrome (EBV-AHS)

Epstein-Barr virus (EBV) infected cells were examined in three cases of EBV-associated hemophagocytic syndrome (EBV-AHS) by analysis of the heterogeneity of terminal repetitive sequences in the EBV genome, indicating monoclonal expansion of EBV-infected cells in all cases. Involvement of T lymphoid cells was determined by the finding of in situ hybridization using [35S]-labeled RNA probes specific for the small EBV-encoded nuclear RNAs, EBER1 and EBER2, in combination with immunostaining for the TCR-beta chain, CD45RO, CD20, CD30 and CD68 antigens in these three cases. The majority of lymphoid cells showing EBER transcripts were stained by antibodies against CD45RO and TCR-beta. In contrast, EBER-specific signals were not detectable on B cells or hemophagocytic cells. These data support the concept that subclinical EBV-associated T cell proliferation is the primary characteristic of EBV-AHS, rather than proliferations of hemophagocytosing histiocytes.

Measurement of angiotensin I converting enzyme inhibition in the heart

Angiotensin (Ang) I converting enzyme (ACE) inhibitors represent a major advance in the treatment of congestive heart failure, and tissue, rather than circulating ACE, may be their major site of action. However, assessments of tissue ACE inhibition in treated patients has not always supported this contention. In these studies, ACE activity was measured in homogenates of sampled tissue by biochemical methods. In the present study, using a model system, we have examined the validity of these tissue-sampling methods. Functional ACE activity was determined by comparing positive inotropic responses to [Pro10]Ang I in either vehicle-pretreated or ACE inhibitor-pretreated papillary muscles. [Pro10]Ang I elicits a response, which is entirely dependent on ACE-mediated conversion to Ang II. The ACE inhibitors studied were captopril, enalaprilat, lisinopril, and quinaprilat. In a parallel study, papillary muscle ACE activity was also measured in homogenates using [125I]MK-351A (a radiolabeled ACE inhibitor) binding. The studies indicate that the tissue-sampling method significantly underestimated functional ACE inhibition in hamster papillary muscles (p < 0.001). Kinetic studies indicated that the half-time for the dissociation of [3H]enalaprilat and [3H]lisinopril from hamster ventricular ACE was 4.5 and 6.2 minutes, respectively. The dissociation of [3H]quinaprilat was biphasic (half-time, 47 and 90 minutes), indicating that the two active sites of somatic ACE differ in their ability to bind to this inhibitor. The rapid rate of ACE inhibitor dissociation suggests that, during the time taken to assay ACE activity biochemically, the enzyme becomes "disinhibited," leading to an underestimation of functional ACE inhibition. ACE inhibitor dissociation rates were partially predictive of the duration of functional ACE inhibition in papillary muscles; other factors that appeared to contribute were "tissue trapping" of the inhibitor and de novo synthesis of ACE in papillary muscles. Quantification of tissue ACE inhibition and its relation to drug efficacy must, therefore, involve a careful consideration of these factors to avoid artifacts in clinical decision making and in assessments of pathogenic mechanisms involved in congestive heart failure.

[Sequential studies of motor nerve conduction in relation to the disease stages of Guillain-Barré syndrome]

We retrospectively studied sequential changes in motor nerve conduction in forearm segments of 17 median nerves in 9 consecutive patients with Guillain-Barré syndrome (GBS). The disease course was divided into 6 stages: progressing, nadir, early-, mid- and late-convalescent, and cured stages. All patients were tested on at least 3 occasions in each different stage. Low amplitude compound muscle action potentials (CMAP) were noted in the progressing and nadir stages, suggesting the presence of conduction block. In the early- and mid-convalescent stages, on the other hand, the delays in distal motor latencies and conduction velocities as well as temporal dispersions of CMAPs were more prominent than in the progressing or nadir stage. These findings suggest that pathophysiological processes are different in the two stages of GBS: demyelination with conduction block predominated in the earlier stage and demyelination without conduction block predominated in the later stage. The former is considered to involve predominantly the relatively smaller motor nerves during the progressing and nadir stages, producing muscle weakness but not causing marked slowing of the motor nerve conduction. The latter is considered to involve predominantly the fastest motor fibers in the later days lasting into the early- and even mid-convalescent stages. This process seems to produce marked conduction slowing, but does not cause prominent muscle weakness. In addition, recovery from the conduction block during the convalescent stages produces temporal dispersions of CMAPs because of the variably slowed conduction velocities.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellular localization and regional distribution of an angiotensin II-forming chymase in the heart

The human heart is a target organ for the octapeptide hormone, angiotensin II (Ang II). Recent studies suggest that the human heart contains a dual pathway of Ang II formation in which the major Ang II-forming enzymes are angiotensin I-converting enzyme (ACE) and chymase. Human heart chymase has recently been purified and its cDNA and gene cloned. This cardiac serine proteinase is the most efficient and specific Ang II-forming enzyme described. To obtain insights into the cardiac sites of chymase-dependent Ang II formation, we examined the cellular localization and regional distribution of chymase in the human heart. Electron microscope immunocytochemistry using an anti-human chymase antibody showed the presence of chymase-like immunoreactivity in the cardiac interstitium and in cytosolic granules of mast cells, endothelial cells, and some mesenchymal interstitial cells. In the cardiac interstitium, chymase-like immunoreactivity is associated with the extracellular matrix. In situ hybridization studies further indicated that chymase mRNA is expressed in endothelial cells and in interstitial cells, including mast cells. Tissue chymase levels were determined by activity assays and by Western blot analyses. Chymase levels were approximately twofold higher in ventricles than in atria. There were no significant differences in chymase levels in ventricular tissues obtained from non-failing donor hearts, failing ischemic hearts, or hearts from patients with ischemic cardiomyopathy. These findings suggest that a major site of chymase-dependent Ang II formation in the heart is the interstitium and that cardiac mast cells, mesenchymal interstitial cells, and endothelial cells are the cellular sites of synthesis and storage of chymase. In the human heart, because ACE levels are highest in the atria and chymase levels are highest in ventricles, it is likely that the relative contribution of ACE and chymase to cardiac Ang II formation varies with the cardiac chamber. Such differences may lead to differential suppression of cardiac Ang II levels during chronic ACE inhibitor therapy in patients with congestive heart failure.

Body sway response to experimental unbalance in normal subjects and patients with unilateral vestibular disorders

The function of maintaining posture during temporary unbalance caused by experimental vestibular asymmetry was studied. Galvanic stimulation to the vestibular nerve causing body deviation to the stimulated ear was given to 31 normal subjects and 16 patients with peripheral vestibular disorders. The velocity of spontaneous body sway and that during body deviation caused by the galvanic stimulation were compared. The spontaneous body sway velocity was significantly higher than that of normal subjects. In normal subjects, the body sway velocity during body deviation remarkably increased, while that in patients did not. It is considered that large body sway in patients might conceal the fine compensatory body sway during the body deviation and that patients with unilateral vestibular dysfunction who have large body sway are always in a dysfunction state similar to that which normal subjects experience during body deviation caused by galvanic stimulation.

[Acute lymphoblastic leukemia with extensive demyelinated lesion of the brain stem during complete remission]

A case of acute lymphoblastic leukemia (ALL) which showed extensive demyelinated lesion of the brain stem during complete remission is presented. A 13 year-old girl who was diagnosed as ALL in February, 1987 was treated according to the TCCSG L84-11 protocol, which induced complete remission in June, 1987. Her condition had been stable until April, 1988 when she abruptly complained of gait disturbance, vertigo and anorexia. She was subsequently admitted to our hospital. At the time of admission, she had ataxic gait, horizontal nystagmus towards right at dextroversion, bilateral exaggerated patellar tendon reflex, emotional incontinence, urinary incontinence and left 6th and 7th nerve palsy. In the middle of May, right spastic hemipalesia and hypesthesia became apparent. Left caudal pontine-basal lesion was suspected and was confirmed by MRI. Her synptoms progressed. Five months after admission, suffered repeated central apnea and died. Autopsy disclosed extensive cervical spinal cord. Cerebrum and cerebellum were intact. No evident findings suggesting the etiology were obtained. Whole skull radiation, intrathecal methotrexate, cytosine arabinoside and hydrocortisone might have contributed to the development of the demyelinated lesion.

Transient myoclonic state with asterixis in elderly patients: a new syndrome?

We report 7 patients who developed acute co-occurrences of fragmentary generalized myoclonus and asterixis. All patients were elderly and had other chronic diseases. This condition appeared acutely, progressed over several hours and then disappeared in 2-3 days with diazepam administration. No sequelae were noted, although most cases developed recurrences. The myoclonus occurred spontaneously and was slightly enhanced by action. The myoclonus was widely distributed but predominated in the neck, shoulder girdle, and upper extremities. Opsoclonus was not noted. Clinically apparent myoclonus was not evoked by sensory stimuli. Asterixis was observed in the upper extremities in all cases. Asterixis-like movements of the protruded tongue were also observed. Neurological findings other than the myoclonus and asterixis were unremarkable. Neither metabolic nor organic abnormalities clearly responsible for this condition were identified. Cerebral potentials preceding the myoclonic jerks recorded in one case suggested that the myoclonus may have been a spontaneous cortical myoclonus. We named this condition a transient myoclonic state with asterixis (TMA). Awareness of this syndrome is clinically important because of its benign nature, although it can recur.

Rounded atelectasis with pleuritis: diagnosis and surgical treatment

A 73-year-old male was admitted with a large rounded atelectasis with pleural effusion. The involved lung was refilled with air as soon as surgical decortication of the thickened visceral pleura covering it was performed. Surgical treatment is believed to be necessary when a large rounded atelectasis with pleural effusion persists for a long time, or when malignancy is not completely excluded.

[Clinical and cytological features of CD7 positive biphenotypic leukemias]

Clinical and cytological features of CD7 positive acute leukemias with biphenotypic characteristics in childhood were documented. From 87 patients with CD7+ acute leukemias, nine patients were selected on the basis of the biphenotypic expression of T-lymphoid and myelomonocytic antigens. The blasts of these patients expressed cell surface CD7, cytoplasmic CD3 and cytoplasmic CD13. In addition to these antigens, surface CD13 was also expressed after short term culture without any mitogens or stimulators. The double PAP method for detecting cytoplasmic antigens (CD3, CD13, beta F1, delta TCS1) was employed in this study. The average age of these patients was higher (10.2 y/o) than patients with common ALL. Mediastinal masses were observed in 4 of 9 patients. They were treated according to the diagnoses based on conventional hematological methods and surface antigen expression. In all 9 patients, complete remission was achieved, however, early relapse was noticed in 7. This study suggests that the leukemia cells of these patients may be derived at an early stage during the differentiation of multipotential hematopoietic stem cells. New therapeutic approaches are necessary to improve the outcome of such T/M biphenotypic leukemias.

Demonstration of receptors for epidermal growth factor on cultured rabbit chondrocytes and regulation of their expression by various growth and differentiation factors

Epidermal growth factor (EGF) receptors were demonstrated on cultured rabbit costal chondrocytes. After crosslinking, the receptors on the cells with 125I-EGF, one major band of 170 KDa was separated by SDS-PAGE. Scatchard analysis demonstrated two classes of EGF receptors with Kd values of 0.3 nM and 1.6 nM. The numbers of high and low affinity receptors were 3,000 and 10,000 per cell, respectively. EGF receptors on chondrocytes were increased by treatment with retinoic acid and interleukin-1 beta, which inhibited proteoglycan synthesis. On the other hand, parathyroid hormone and dibutyryl cyclic AMP, which stimulated proteoglycan synthesis, decreased the number of EGF receptors. Treatments with these agents did not change the affinity of the receptors. These findings suggest that the number of EGF receptors is a negative marker of chondrocyte differentiation.

Oral administration of a streptococcal agent OK-432 activates alveolar macrophages in mice

The effect of orally administered OK-432, a streptococcal preparation, on the functions of alveolar macrophages in mice was examined. The oral administration of OK-432 (1, 2 or 4 KE, four times every 3 days) augmented phagocytic activity, lysosomal enzyme activity and interleukin 1 (IL-1) production of murine alveolar macrophages recovered 5 days after the final administration while it did not augment H2O2 production. The number of alveolar macrophages was not affected by the same treatment. These results suggested that oral administration of OK-432 activates alveolar macrophages qualitatively to protect the lung from the metastasis of cancer cells and infectious diseases by pathogenic micro-organisms.

Mild exercise decreases plasma endogenous digitalislike substance in hypertensive individuals

Changes in a plasma endogenous digitalislike substance were investigated in relation to the antihypertensive mechanism of mild exercise. Fifteen women with mild essential hypertension and seven normotensive female volunteers were divided into exercised hypertensive (n = 10), nonexercised hypertensive (n = 5), and nonexercised normotensive (n = 7) groups. A 4-week general clinical observation period preceded the study period of 10 weeks. The exercised hypertensive individuals were treated with a lactate threshold exercise that corresponded to approximately 50% of the maximum oxygen consumption three times a week, whereas the nonexercised groups were observed at the outpatient clinic as control groups. In the exercised group, systolic blood pressure fell by 7 mm Hg (p = 0.05), diastolic by 6 mm Hg (p less than 0.01), and mean blood pressure by 7 mm Hg (p less than 0.01) after 10 weeks. The reduction in the plasma endogenous digitalislike substance was significant after 7 (-1.02 ng/ml, p less than 0.05) and 10 (-1.04 ng/ml, p less than 0.05) weeks in this group. It positively correlated with the reduction in diastolic (r = 0.70, p less than 0.05) or mean (r = 0.66, p less than 0.05) blood pressure and with changes in plasma norepinephrine (r = 0.76, p less than 0.05). The mean corpuscular volume of erythrocytes decreased (-1.7 fl, p less than 0.01) after 10 weeks of exercise, and the plasma volume index tended to decrease (-108 ml/m2, p = 0.28). In the control groups, significant changes in blood pressure and plasma endogenous digitalislike substance were not observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Active and inactive renin after exercise

The effects of graded exercise on plasma concentrations of active and inactive renin were studied in seven healthy men. Exercise was performed on a cycle ergometer at four different exercise intensities (corresponding to 30%, 50%, 80% and 87% of VO2max) for 10 min each. Concentrations of active renin and total renin after activation by trypsin were measured by direct immunoradiometric assay. Non-trypsin-activated renin concentration (inactive) was obtained by subtraction. Active renin concentrations at 30%, 50%, 80% and 87% of VO2max were 1.2, 1.9, 3.1 and 4.6 times higher than the control concentration, respectively. Similar increases in plasma renin concentration, determined by conventional enzymatic assay, were observed at every stage. In contrast, changes in inactive renin concentration were not significant at any stage. Significant increases in noradrenaline concentration were found at every exercise stage, but adrenaline, aldosterone and lactate concentrations were significantly elevated only after exercise at 50%, 80% and 87% of VO2max. The similarity between the changes in concentration of active renin and noradrenaline would suggest that sympathetic nerve activity may have been responsible either for the release of active renin or for the conversion of inactive renin to its active form in the kidney.

Multiple determinants for the high substrate specificity of an angiotensin II-forming chymase from the human heart

Human heart chymase, a chymotrypsin-like serine proteinase that hydrolyzes the Phe8-His9 bond in angiotensin I (Ang I) to yield the octapeptide hormone angiotensin II (Ang II) and His-Leu, is the most specific, efficient Ang II-forming enzyme described. Other mammalian chymases display a much broader substrate specificity. To better define its substrate specificity, we have mapped the extended substrate-binding site of human heart chymase using Ang I analogs. The enzyme has a preference for aromatic amino acids phenylalanine, tyrosine, and tryptophan at the P1 site. At the S2 subsite there is a significant preference for proline over hydrophobic or hydrophilic amino acids. There is no clear preference for hydrophobic or hydrophilic amino acids at the S'1 and S'2 subsites, but an Ang I analog containing a P'1 proline is not hydrolyzed and one with a P'2 proline is hydrolyzed poorly. An increasing reduction in reactivity occurs when the P position amino acids in Ang I are deleted sequentially from the N terminus. An increase or decrease in the length of the His-Leu leaving group also produces a marked decrease in reactivity. No single determinant in Ang I is preeminently required for efficient catalysis, but several factors acting synergistically appear to be important. Thus, we propose that ideal substrates for human heart chymase should contain the structure nXaa-Pro-[Phe, Tyr, or Trp]-Yaa-Yaa, where n greater than or equal to 6; Xaa = any amino acid; Yaa = any amino acid except proline. This structure exists in Ang I and neurotensin, both of which are good substrates for human heart chymase. These findings indicate that the selection of the scissile bond by the extended substrate-binding site of human heart chymase is more restricted than that in other chymases.

Cloning of the gene and cDNA for human heart chymase

We have recently identified and characterized a chymotrypsin-like serine proteinase in human heart (human heart chymase) that is the most catalytically efficient enzyme described, thus far, for the cleavage of angiotensin I to yield angiotensin II and the dipeptide His-Leu. Compared to other chymases, this enzyme also has an unusually high degree of specificity for the substrate angiotensin I. We report here the molecular cloning and nucleotide sequence of the gene and cDNA encoding human heart chymase, and determination of its entire deduced amino acid sequence. These data indicate that human heart chymase is highly homologous to other members of the chymase subfamily of chymotrypsin-like proteinases and, most likely, all evolved from a common ancestral gene. Potential regulatory elements found in the 5'-untranslated region of other chymases are also found in the human heart chymase gene. However, this gene lacks mast cell-specific sequences found in the 5'- and 3'-untranslated regions of the rat chymase II gene. In addition, human heart chymase contains clusters of unique amino acid sequences located at key positions likely involved in substrate binding, which may contribute to its high substrate specificity. These contrasting features of the human heart chymase gene and cDNA, and the potential determinants of its primary structure that underlie its unique functional characteristics are considered.

Wound healing following stab injury on rat cerebral cortex

We examined how wound healing was initiated and completed. Stab injury was made over the right parietal cortex with 2.5 mm depth and 4 mm length. Either 3 days, 7 days or 1 month after this operation, operated rats were perfused and fixed with 4% paraformaldehyde. The brains were removed, embedded in paraffin, cut coronally at a level of caudate-putamen complex and thin-sliced into 6 microns thick sections with a microtome. The sections were stained immunohistochemically for detection of glial fibrillary acidic protein (GFAP), and co-stained for myelination with Woelcke's staining method. Sections were also stained immunohistochemically for Laminin after pretreatment by pepsin. Furthermore, the sections were stained either haematoxylin-eosin staining, Laidlaw's Reticulum staining for evaluation of reticulin and phosphotungusten acid haematoxylin (PTAH) staining for delination of collagen. We, first, confirmed astrocytic proliferation induced by the stab injury. Then, astrocytes can be seen crowded around the injured site 7 days after injury. Both Laminin and Reticulum stain show the so-called neovascularization around the stab wound 7 days after injury when astrocytes proliferated most vigorously as mentioned above. PTAH stain showed collagenous fibre 1 month after injury when astrocytes congregated along the wound site, and Laminin fibres were localized to the injury site. Reticulin fibres disappeared. In conclusion, it takes more than a month for the wound site to regain the steady state.

Immunological classification of childhood acute lymphoblastic leukemia

Seven hundred and forty-four newly diagnosed patients with acute leukemias between 1978 and 1990 were classified on the basis of immunological phenotypes. The majority of the patients were enrolled in the Tokyo Children's Cancer Study Group (TCCSG) studies. The incidence of subclassification of acute leukemias in this study was as follows: 522 patients with ALL (70%), 139 patients with ANLL (18%), 29 patients with biphenotypic leukemia, 8 patients with Ph1-positive acute leukemia (Ph1-AL), and 45 patients with infant leukemia. ALLs were classified into common ALL (cALL, 77%), T-ALL (15%), B-ALL (4%), and unclassified ALL (3%). The incidence of ALL subtypes in this study reflected those of TCCSG. Biphenotypic leukemias were categorized into 4 groups as follows; 1) cALL with positive myelomonocytic antigen(s) (N = 11), 2) unclassified ALL with positive myelomonocytic antigen(s) (N = 5), 3) ANLL with positive B-lymphoid antigen(s) (N = 4), and 4) acute leukemia with positive T-lymphoid and myeloid antigen(s). Infant leukemias were classified into ALL type (N = 27) and ANLL type (N = 18). In this present study, clinical features and immunological phenotypes of the acute leukemias with a poor prognosis, i.e. biphenotypic leukemia, Ph1-AL, and infant leukemia are analyzed and discussed.

Effects of various growth and differentiation factors on expression of parathyroid hormone receptors on rabbit costal chondrocytes in culture

In our preliminary report we demonstrated PTH receptors on rabbit costal chondrocytes in culture. In the present study regulation of expression of PTH receptors of the chondrocytes by various growth and differentiation factors and its relation to the synthesis of glycosaminoglycan (GAG), a differentiated phenotype of chondrocytes, were investigated. Treatment with retinoic acid decreased GAG synthesis in cultured chondrocytes and the number of PTH receptors, measured by binding of [125I]-[Nle8,18,Tyr34]bovine PTH-(1-34) amide to the cells. However, the affinity of the receptors did not change. The decrease in the number of PTH receptors was dose and time dependent and parallel to the decrease in GAG synthesis. When chondrocytes that had been treated with retinoic acid were cultured in the absence of retinoic acid for 3 days, both their GAG synthesis and their number of PTH receptors were restored. Epidermal growth factor and fibroblast growth factor also decreased both the number of PTH receptors and GAG synthesis in the cells. However, these treatments did not change their affinity. Treatment with insulin-like growth factor-I, (Bu)2cAMP, and transforming growth factor-beta resulted in increases in GAG synthesis as well as in the number of PTH receptors without any change in their affinity. In addition, the PTH-stimulated cAMP level in chondrocytes pretreated with retinoic acid, epidermal growth factor, and fibroblast growth factor was lower than that in control cells. On the other hand, the PTH-stimulated cAMP level in chondrocytes pretreated with insulin-like growth factor-I and transforming growth factor-beta was higher than that in control cells. These observations suggest that the increase in the number of PTH receptors on chondrocytes is closely related to expression of the differentiated phenotype of chondrocytes and that the number of the receptors is a good marker of the differentiated phenotype of chondrocytes.

Establishment from a human chondrosarcoma of a new immortal cell line with high tumorigenicity in vivo, which is able to form proteoglycan-rich cartilage-like nodules and to respond to insulin in vitro

The human chondrosarcoma cell line (HCS-2/8) established by our group expresses cartilage phenotypes such as production of cartilage-type proteoglycans and collagen type II, but its tumorigenicity is low. To develop an in vitro experimental system for studies of human chondrosarcomas, a new immortal cell line of human chondrosarcoma, named HCS-2/A, was established from the same tumor. HCS-2/A cells proliferated with a doubling time of 3 1/2 days in a medium containing 20% fetal bovine serum (FBS). This growth rate was comparable to that of HCS-2/8 cells. However, HCS-2/A cells proliferated more rapidly than HCS-2/8 cells in the presence of 2-10% FBS. Like HCS-2/8 cells, HCS-2/A cells had a polygonal shape in sparse cultures and became spherical as they reached confluence, after which they formed nodules composed of multilayered cells and a large quantity of extracellular matrix showing strong metachromasia. The nodules formed by HCS-2/A cells were thicker and also larger in diameter than those formed by HCS-2/8 cells. Electron microscopically, the cells in the nodules resembled chondrocytes in vivo, but each cell had an irregular-shaped nucleus which is a characteristics of tumor cells. The cells actively synthesized "cartilage-specific" large proteoglycans and their level of proteoglycan synthesis was comparable to that of HCS-2/8 cells. Insulin, which stimulates proteoglycan and DNA syntheses in cultured chondrocytes, markedly increased proteoglycan synthesis in HCS-2/A cells. On the other hand, the hormone only slightly increased proteoglycan synthesis in HCS-2/8 cells. Insulin also stimulated DNA synthesis in cultured HCS-2/A cells, but not in HCS-2/8 cells. Immunostaining revealed that HCS-2/A cells produced type-II collagen but not type-I collagen. However, the level of collagen synthesis of HCS-2/A cells was lower than that of HCS-2/8 cells. Inoculation of HCS-2/A cells into athymic mice resulted in the formation of chondrosarcomas that grew faster than those arising from HCS-2/8 cells.

[Studies on the structure of the matrix in cementum regenerated in healing process of periodontal tissues]

The purpose of this study was to investigate the structure of the matrix in regenerated cementum on surgically denuded root dentin and on acid-demineralized root dentin in dogs. Non-decalcified specimens were examined two to 16 weeks after surgery. The arrangement of the matrix fiber, the fiber component and the crystal deposition of the cementum were studied by light microscopy and electron microscopy. The results were as follows: 1. There were many differences in the structures of regenerated cementum. The differences were dependent on the presence of resorption of the root dentin, existence of lamellar structure, and density of Sharpey's fibers. 2. Regions without surface resorption of dentin exhibited a dense deposition of crystallites and a rare arrangement of collagen fibrils at the cementodentinal junction. 3. Regions of surface resorption of dentin exhibited a layer where dentinal and cemental crystallites were amalgamated, and/or dentinal and cemental matrix fibers were interdigitated at the cementodentinal junction. 4. Regions subjected to artificial demineralization by citric acid exhibited similar structure to that where surface resorption of dentin was observed. 5. It is suggested that the resorption of dentinal surface during the healing process of a surgically created wound in periodontal tissue occurred as an intermediate stage followed by the establishment of a stronger bind by the increase of superficial contact area at the cementodentinal junction.

Basic fibroblast growth factor prevents thalamic degeneration after cortical infarction

In the focal infarction model of the rat middle cerebral artery (MCA), the thalamus of the occluded side becomes gradually atrophic, mainly because of retrograde degeneration. We determined whether basic fibroblast growth factor (bFGF) administered intracisternally could prevent this thalamic atrophy. We occluded the left MCA through a small cranial opening, and animals were then divided into two groups. One group received intracisternal injections of recombinant bFGF (1 microgram dissolved in 0.1 ml of saline with 2% rat serum) starting 1 day after occlusion and repeated once a week to a total dose of 4 micrograms by four injections. The other group received vehicle solution by the same schedule. The animals were perfused and fixed at 28 days after occlusion, and histological examination was made at the level of the caudoputamen and thalamus. In the bFGF-treated rats, the area of the posterior ventral thalamus of the occluded side was 93% of that of the contralateral side, i.e., significantly larger than in the normal saline-treated rats (75%, p less than 0.01). The infarction size was not statistically different in the two groups. Microscopic observation indicated that normal-saline-treated animals showed shrinkage and disappearance of thalamic neurons, whereas bFGF-treated groups showed preservation of thalamic neurons. Computerized analysis of the cell size substantiated this observation. To assess the effect of bFGF on astrocytes, bFGF or vehicle solution was injected into normal rats, and their histology was evaluated at 1, 2, and 4 weeks after injection. The bFGF-injected group showed a significant increase in glial fibrillary acidic protein-positive astrocytes in the brain tissue facing the ventriculocisternal system.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional p75 interleukin-2 receptor expression on the fresh blast cells in childhood acute lymphoblastic leukemia with natural killer cell properties

Neoplastic cells of childhood acute lymphoblastic leukemia (ALL) with natural killer (NK) cell properties were studied for the expression of p75 interleukin-2 receptors (IL-2R) and the receptor functions. Freshly prepared blast cells from a patient with ALL had NK cell properties: (1) the phenotype such as CD56+, CD2+, E-rosette+, CD3-, and CD19-; and (2) the presence of spontaneous cytotoxicity against NK-sensitive K562 target cells. Although p55 Tac antigen was not detectable, there was the expression of p75 IL-2R on the freshly prepared blast cells: 70% of the cells reacted with Mik-beta 1 monoclonal antibody against p75 IL-2R as determined by flow cytometry. Two-color flow cytometry revealed that the blast cells expressed both p75 IL-2R and NKH-1. NK activity of the blast cells was augmented by their treatment with 1,000 U/ml recombinant IL-2 (rIL-2): the cytotoxicity level as percentage lysis increased to 38.7% from 22.0% when the normal lymphocyte value increased to 62.1% from 46.2%. Although the blast cells possessed no apparent level of proliferative capacity, the addition of 1,000 U/ml rIL-2 yielded a 2.7-fold increase in their thymidine uptake. These results demonstrate the expression of functional p75 IL-2R on the patient's blast cells with NK cell properties.

Neurotoxicity caused by glutamate after subcritical hypoxia is prevented by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX): an in vitro study using rat hippocampal neurons

Neurotoxicity of glutamate in conjunction with subcritical hypoxia was determined in vitro using hippocampal neurons obtained from 18-day-old rat fetuses. Neurons were plated at a low density and maintained for 3 days in a chemically defined medium without glutamate. When glutamate + was added after subcritical hypoxic stress, a low dose of glutamate, even at 10 microM, could cause significant neuronal loss in the following 24 h. The observed neurotoxicity to low glutamate dose (10-100 microM) could completely be prevented by 5 microM of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). This protective effect of CNQX was more potent than that of MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate). The mechanism by which glutamate is transformed from a neurotransmitter to a neurotoxin is discussed.

Effect of intraperitoneally administered beta-1,3-glucan, SSG, obtained from Sclerotinia sclerotiorum IFO 9395 on the functions of murine alveolar macrophages

The effect of intraperitoneally (i.p.) administered SSG, a beta-1,3-glucan obtained from the culture filtrate of the fungus Sclerotinia sclerotiorum IFO 9395, on the functions of alveolar macrophages (AM) in CDF1 mice was examined. SSG administered i.p. increased the number of AM and enhanced several functions of murine AM (lysosomal enzyme activity, phagocytic activity, candidacidal activity, H2O2 production and interleukin 1 (IL-1) production) at a dose of 250 micrograms/mouse on days 1 and 8, especially on day 8. Furthermore, SSG (250 micrograms/mouse) administered i.p. for 10 consecutive days significantly inhibited the experimental pulmonary metastasis of Lewis Lung Carcinoma (3LL) on BDF1 mice.

Changes of dopamine and atrial natriuretic factor by mild exercise for hypertensives

Changes of humoral factors related to the regulation of fluid volume were investigated in exercise training for hypertensives. Twelve patients with essential hypertension were treated with an aerobic exercise for 10 weeks. A significant reduction in blood pressure from 161 +/- 3/100 +/- 2 mmHg at week 0 to 142 +/- 5/94 +/- 3 mmHg at week 4 was observed which continued until week 10. Urine dopamine was increased significantly at the 4th week from 386 +/- 29.4 micrograms/day at week 0 to 524 +/- 46.3 micrograms/day and plasma atrial natriuretic factor (ANF) was significantly reduced at the 4th week, from 41.5 +/- 2.7 pg/ml at week 0 to 32.6 +/- 3.7 pg/ml. Plasma volume was found reduced significantly from 2,531 +/- 166 ml/m2 at week 0 to 2,221 +/- 165 ml/m2 at week 10. These results suggest that the increase of dopamine and reduction of plasma ANF which took place at the early stage might be related to, at least in part, the depletion of plasma volume and the reduction of blood pressure in mild exercise for hypertensives.

Human recombinant superoxide dismutase protects primary cultured neurons against hypoxic injury

Induction of free radicals and succeeding cascade reactions of lipid peroxidation are known to cause neuronal damage in cases of cerebral ischemia. We studied whether hypoxic stress in vitro induces the formation of these cytotoxic materials, and whether superoxide dismutase (SOD) protects cultured neurons from hypoxic stress. We used human recombinant SOD (rSOD), which is structurally homologous to native human SOD, the only exception being that the N terminus is not acetylated. First, we detected free radicals by means of nitroblue tetrazolium (NBT) and assured that hypoxic stress to the cultured neurons induced the formation of peroxidation materials. Immediately after the hypoxic stress, the neurons showed no reduction from NBT to formazan. Striking NBT coloration of the somata, however, started to appear 30 min after reoxygenation, and the percentage of formazan-positive neurons increased during up to 32 h of the experimental period. About 50% of the neurons stained positively 24 h after hypoxia. This shows that rSOD is needed immediately after reoxygenation. Secondly, we examined whether rSOD exerts a cytoprotective activity against hypoxia. rSOD, with the application of proper treatment which incorporates rSOD into the target neuron, prevents the neuronal damage induced by oxide anions, which plays an important role in acute neuronal death accompanied by hypoxia. It can be concluded that, when intracellularly present in sufficient amounts, rSOD is useful for the treatment of hypoxic damage.

Oral administration of a streptococcal agent OK-432 activates peritoneal macrophages in mice

The effect of orally administered OK-432, a streptococcal preparation, on the function of peritoneal macrophages in mice was examined. The administration of OK-432 orally (1 KE or 2 KE, four times every three days) did not affect the numbers of both total peritoneal cells and macrophages recovered five days after the final administration. However, the macrophages exhibited an increase in their spreading ability. Other functions of the peritoneal macrophages including lysosomal enzyme activity, phagocytic activity and interleukin 1 (IL-1) production were also enhanced significantly by the oral administration of OK-432 (1 KE or 2 KE). The production of H2O2, however, was not affected by the same treatment with OK-432. The activation of peritoneal macrophages by orally administered OK-432 reported here may contribute to expansion of the clinical application of this drug.

Identification of a highly specific chymase as the major angiotensin II-forming enzyme in the human heart

Although angiotensin II (Ang II)-forming enzymatic activity in the human left cardiac ventricle is minimally inhibited by angiotensin I (Ang I) converting enzyme inhibitors, over 75% of this activity is inhibited by serine proteinase inhibitors (Urata, H., Healy, B., Stewart, R. W., Bumpus, F. M., and Husain, A. (1990) Circ. Res. 66, 883-890). We now report the identification and characterization of the major Ang II-forming, neutral serine proteinase, from left ventricular tissues of the human heart. A 115,150-fold purification from human cardiac membranes yielded a purified protein with an Mr of 30,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Based upon its amino-terminal sequence, the major human cardiac Ang II-forming proteinase appears to be a novel member of the chymase subfamily of chymotrypsin-like serine proteinases. Human heart chymase was completely inhibited by the serine proteinase inhibitors, soybean trypsin inhibitor, phenylmethylsulfonyl fluoride, and chymostatin. It was partially inhibited by p-tosyl-L-phenylalanine chloromethyl ketone, but was not inhibited by p-tosyl-L-lysine chloromethyl ketone, and aprotinin. Also, human heart chymase was not inhibited by inhibitors of the other three classes of proteinases. Human heart chymase has a high specificity for the conversion of Ang I to Ang II and the Ang I-carboxyl-terminal dipeptide His-Leu (Km = 60 microM; Kcat = 11,900 min-1; Kcat/Km = 198 min-1 microM-1). Human heart chymase did not degrade several peptide hormones, including Ang II, bradykinin, and vasoactive intestinal peptide, nor did it form Ang II from angiotensinogen. The high substrate specificity of human heart chymase for Ang I distinguishes it from other Ang II-forming enzymes including Ang I converting enzyme, tonin, kallikrein, cathepsin G, and other known chymases.

Oxygen protects rat brain from ischaemic injury

Interruption of the oxygen supply to the brain promotes functional and structural damage of the brain, such as oedema and swelling. The most prominent cellular reaction to this type of damage has been found to be trophic or proliferative changes in glial cells. We examined dynamic changes in glial cells adjacent to the infarcted tissue in response to oxygenation. Results showed that astrocyte proliferation was seen more at 3 than at 7 days after middle cerebral artery occlusion, while their numbers with and without oxygenation were almost the same. The proliferation of microglia, however, was seen more with than without oxygenation. However, microglia seem to be able to secrete an angiogenetic factor under hypoxic conditions, and are active in terms of superoxide dismutase (SOD). Cerebral blood flow is directly related to tissue oxygen content and its autoregulatory capacity has been found to be greater as the volume contracts. As a result, we suggest that the application of oxygen-treated microglia to ischaemic tissue could diminish tissue damage, and that the most effective oxygenation can be achieved by the withdrawal of blood and reduction of the intracranial pressure.

Fertilisation of bovine oocytes by the injection of immobilised, killed spermatozoa

Immobilised (killed) bovine spermatozoa were microinjected into bovine oocytes matured in vitro and cultured for six to nine days in vitro. A co-culture system with cumulus cells was used for the embryonic development. After one to two, three to four, five to six and seven to eight days the proportions of the oocytes which had developed to the two to four-cell, six to 12-cell, morula and blastocyst stages were 12.0 per cent (61 of 507), 9.3 per cent (47 of 507), 5.9 per cent (30 of 507) and 7.8 per cent (nine of 115), respectively. In contrast, none of the sham-operated group developed beyond the six-cell stage. This is the first report to show that bovine oocytes matured in vitro can undergo cleavage to the blastocyst stage after the injection of sperm in vitro. In addition, normal calves were obtained from the transfers of some of the embryos to recipient cows.

Hippocampal neurons become more vulnerable to glutamate after subcritical hypoxia: an in vitro study

The neurotoxicity of glutamate and hypoxia was investigated in vitro on hippocampal neurons, which were obtained from 18-day-old rat fetuses and were maintained for 3 days in culture. Chemically defined medium without glutamate was used and the plating density was low enough that the effect of exogenously added glutamate could be directly evaluated. In the normal culture condition 1 mM glutamate was necessary to cause significant neuronal loss in the following 24 h. In marked contrast, when glutamate was added after subcritical hypoxic stress, a dose of glutamate as low as 10 microM could exhibit neurotoxicity. Administration of MK-801, a selective noncompetitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, could in part reverse this increased susceptibility to low-dose glutamate after hypoxia, although MK-801 could not protect hippocampal neurons from high-dose glutamate. Therefore, both the NMDA receptor and other subclasses of the glutamate receptor may be involved in this neurotoxicity of glutamate. Different mechanisms of glutamate neurotoxicity with high and low doses are discussed. Our results showed that hippocampal neurons exposed to subcritical hypoxia become more vulnerable to glutamate than those without hypoxia. This increased susceptibility is of great interest to understanding the mechanism of slowly ongoing neuronal loss caused by ischemia or epilepsy.

Effects of tumor necrosis factor alpha on proliferation and expression of differentiated phenotypes in rabbit costal chondrocytes in culture

Tumor necrosis factor alpha (TNF alpha) decreased the synthesis of glycosaminoglycan (GAG) in rabbit costal chondrocytes in culture, but did not stimulate the release of GAG from cell layers. Like chondrocytes cultured in control medium, chondrocytes cultured in the presence of TNF alpha produced putative "cartilage-specific" proteoglycans identified by density gradient centrifugation under dissociative conditions. Although TNF alpha decreased the synthesis of the proteoglycans, it did not change their monomeric size, which is a marker of cartilage phenotypes. Moreover, TNF alpha did not affect the responsiveness to parathyroid hormone, insulin-like growth factor I, or transforming growth factor beta, which is known to stimulate GAG synthesis in cultured chondrocytes. TNF alpha decreased the alkaline phosphatase activity in the chondrocytes dose dependently. On the other hand, it stimulated their DNA synthesis slightly, but significantly. The stimulatory effect of TNF alpha on DNA synthesis was potentiated by fibroblast growth factor, epidermal growth factor, and fetal bovine serum. These findings suggest that in the presence of hormones and growth factors, TNF alpha promotes the proliferation of chondrocytes while suppressing their further differentiation at the stage of synthesis of cartilage-specific proteoglycans.

Effect of astrocyte-derived factors on ischemic brain edema induced by rat MCA occlusion

To clarify whether astrocyte-derived factors may protect cerebral tissue from ischemia, we examined brain edema, demyelination and astrocyte proliferation in brains with focal ischemia and treated with astrocyte-cultured medium. We occluded the left middle cerebral artery of rats and implanted the Osmotic Minipump, which continuously infused the glial-cultured medium or control medium into the left lateral ventricle. Animals were sacrificed at 3 days or 7 days after occlusion. Brains of both groups were compared by several markers, i.e. extravasation of Evans blue, demyelination by Woelcke's staining and glial proliferation by GFAP staining. We found the astrocyte-cultured medium reduced leakage of Evans blue-plasma protein complex from ischemic lesions and reduced the size of demyelinated lesions. However, the degree of astrocyte proliferation was similar in both groups. From these data, we speculate that humoral factors derived from cultured astrocytes lessened the brain edema by modifying the blood-brain barrier. These factors might also induce proliferation of the microglia, and may protect the neurons from secondary injury by oxygen-free radicals.

[Atypical computed tomographic appearance of herpes simplex encephalitis]

In cases of herpes simplex encephalitis, a low density lesion in the temporal lobe is a common CT finding, whereas hemorrhagic lesion is rarely observed on CT in this disorder despite the frequent occurrence on pathologic studies. Two cases of hemorrhagic lesion observed on CT in herpes simplex encephalitis are reported, and atypical CT findings of herpes simplex encephalitis is discussed.

Tumor angiogenesis and polyamines: alpha-difluoromethylornithine, an irreversible inhibitor of ornithine decarboxylase, inhibits B16 melanoma-induced angiogenesis in ovo and the proliferation of vascular endothelial cells in vitro

alpha-Difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, inhibited B16 melanoma-induced angiogenesis in chick embryo chorioallantoic membrane and subsequently the growth of the tumor on the chorioallantoic membrane. These inhibitions were reversed by exogenous putrescine and spermidine. DFMO also inhibited rapid neovascularization in yolk sac membrane of 4-day-old chick embryos and the inhibition was reversed by exogenous putrescine and spermidine. DFMO strongly inhibited DNA synthesis and proliferation of bovine pulmonary artery endothelial (BPAE) cells in culture and decreased their ornithine decarboxylase activity and intracellular polyamine concentrations. Addition of putrescine to the culture medium of DFMO-treated BPAE cells restored their intracellular putrescine and spermidine concentrations and their DNA synthesis and proliferation. Addition of spermidine to cultures of DFMO-treated BPAE cells restored their intracellular spermidine concentration and their DNA synthesis and proliferation. DFMO inhibited the proliferation of B16 melanoma cells in culture but the inhibitory effect was much less than that on BPAE cells. When one-half the monolayer of confluent cultures of BPAE cells had been peeled off, addition of DFMO to the cultures inhibited the proliferation and extension of the BPAE cells into the vacant area but had no effect on stationary cells in the remaining half of the monolayer, suggesting that it inhibited induction of proliferation of endothelial cells. These findings suggest that the antitumor activity of DFMO against solid tumors is probably due more to its inhibition of tumor-induced angiogenesis by inhibition of proliferation of endothelial cells induced by polyamine depletion than to a direct effect on tumor cell proliferation.