Mutation of a conserved amino acid residue (tryptophan 1173) in the tyrosine kinase domain of the IGF-I receptor abolishes autophosphorylation but does not eliminate biologic function

The amino acid sequence of the tyrosine kinase domain of the insulin-like growth factor-I (IGF-I) receptor is 84% identical to the sequence of the analogous region of the insulin receptor. A naturally occurring mutation of the tryptophan residue at position 1200 of the insulin receptor to serine results in impaired beta subunit autophosphorylation of wheat germ agglutinin-purified receptors, severely impaired thymidine incorporation and moderately reduced glycogen synthesis; however, glucose uptake was unaffected. To study the importance of this residue in IGF-I receptor function, we mutated the analogous tryptophan residue at position 1173 of the IGF-I receptor to serine and overexpressed the mutant receptor in NIH-3T3 cells. In cell lines overexpressing this mutant IGF-I receptor, beta subunit autophosphorylation was severely reduced. Additionally, the overexpressed mutant receptors exhibited a dominant-negative effect on IGF-I-stimulated autophosphorylation of endogenous mouse IGF-I receptors. Phosphorylation of insulin receptor substrate (IRS)-1 in intact cells by the mutant IGF-I receptors was similar to the level of IRS-1 phosphorylation seen in the parental NIH-3T3 cells, but there was no obvious dominant-negative effect on IRS-1 phosphorylation. Wheat germ agglutinin-purified mutant receptors were as active in phosphorylating poly-(Glu,Tyr) 4:1 as wild-type IGF-I receptors, suggesting that, in intact cells, additional factors are necessary in order for the IGF-I receptor to phosphorylate IRS-1. Thymidine incorporation was severely reduced in one clone overexpressing the mutant IGF-I receptor and abolished in a second clone. Glucose uptake in both clones was reduced to about half of that seen in a cell line over-expressing wild-type IGF-I receptors. Thus, we propose that the tryptophan residue at position 1173 of the IGF-I receptor is important in the regulation of autophosphorylation in vivo. This study again confirms that high levels of autophosphorylation are not required for mediation of all of the biologic activities of the IGF-I receptor.

Amphoteric drugs. 3. Synthesis and antiallergic activity of 3-[(5,11-dihydro[1]benzoxepino[4,3-b]pyridin-11- ylidene)piperidino]propionic acid derivatives and related compounds

An important approach to the design of antiallergic agents with reduced penetration into the central nervous system (CNS) is described. A series of 3-[(5,11- dihydro[1]benzoxepino[4,3-b]-pyridin-11-ylidene)piperidino]propion ic acid derivatives (31-47) and related compounds (48-54) were synthesized and evaluated for antiallergic activity and penetration of a compound into the CNS in comparison with the corresponding 6H-dibenz[b,e]oxepin derivative (3). Combination of zwitterionization and introduction of a pyridine component resulted in an increase in antiallergic activity and a great reduction of penetration into the CNS, which was evaluated by the selectivity (B/A) of antihistaminic activities in the central system [ID50 value (B) for ex vivo H1 binding to mouse brain membranes] and in the peripheral system [ED50 value (A) for inhibitory effect on histamine-induced increase in vascular permeability in mice]. This surprising reduction of penetration into the CNS could be considered on the basis of an increase in hydrophilicity caused by both of the zwitterionization and the introduction of a pyridine component. 3-[4-(8-Fluoro-5,11-dihydro[1]benzoxepino[4,3- b]pyridin-11-ylidene)piperidino]propionic acid (33) exhibited a strong antiallergic effect in various experimental models and very low penetration into the CNS. Compound 33 (HSR-609) is now under clinical trial as a promising antiallergic agent with greatly reduced penetration into the CNS.

Cerebral infarction in a young adult associated with protein C deficiency. A case report

Protein C deficiency is a cause of thromboembolic disease. Venous thrombosis is the most common clinical manifestation. Arterial thrombosis is unusual and involvement of the intracranial arteries is especially rare. Herein the authors describe a case of cerebral [correction of cerebellar] infarction associated with protein C deficiency and review the relevant medical literature. A thirty-year-old man was hospitalized because of dysarthria, right limb ataxia, and a gait disturbance. Cranial computed tomography disclosed an infarction in the right cerebellar hemisphere and brachium pontis. Three months earlier the patient had had a transient ischemic attack with truncal ataxia and gait disturbances. On admission, the protein C antigen was 57% and protein C activity was 45%. Investigation of family members revealed protein C deficiency in an uncle. Literature review of stroke cases associated with protein C deficiency revealed that most had had a previous vascular event and/or a positive family history or had used oral contraceptives chronically. Protein C deficiency should be considered in young stroke patients with a positive family history of vaso-occlusive disease, previous ischemic events, or chronic oral contraceptive use.

[Transendoscopic microvascular Doppler sonography for the assessment of hemodynamics of esophageal and gastric varices]

The importance of unravel hemodynamics at the stomach and esophagus in patients with portal hypertension has been described for understanding pathophysiology and treatment of varices associated with portal hypertension. Microvascular Doppler sonogrlaphy (MF20) is a pulse Doppler method with 20 MHz which is able to measure velocity and direction of blood flow in microvessel. We invented transendoscopic microvascular Doppler sonography (EMDS) by connecting a tiny probe of one mm in diameter with an endoscopy. We evaluated direction of blood flow in the esophageal and gastric varices by EMDS and angiography in 21 untreated and 26 shunt-operated patients with portal hypertension. In all of untreated patients direction of blood flow in the varices was toward the probe (forward). Results obtained with EMDS were consistent with angiographic results available in 13 patients. Direction of blood flow after shunt operation was away from the probe in 21 out of 26 patients. The comparison with angiography revealed that post-operative patients with "away" blood flow in varices had maintained satisfactory shunt selectivity without hepatofugal collateral and it proved that the direction of blood flow was toward the shunt at lower pressure. In conclusion EMDS is useful as an evaluation method for hemodynamics in varices of the esophagus and stomach.

The role of p53 inactivation in human cervical cell carcinoma development

We investigated the association between human papillomavirus (HPV) infection and p53 gene mutation in 47 primary uterine cervical cancers. HPV DNA sequences were present in 43 cancers (91.5%), and one of these cancers contained a p53 gene mutation. In addition, one of the remaining four HPV-negative cancers also contained a p53 gene mutation. As a result, p53 inactivation corresponded to the development of 44 of the primary uterine cervical cancers studied (93.6%). We obtained both primary and recurrent tumours from four cases. In two of these cases, the HPV genomes that were present in an episomal state in the primary tumours were observed to have disappeared in the recurrent tumours. One of these recurrent tumours also contained a p53 gene mutation, which suggested the possibility that p53 inactivation was required in order to maintain the aggressive behaviour in this cancer either by an HPV infection or by a p53 gene mutation. No MDM2 gene amplification was observed in the tumours that carried neither HPV DNAs nor p53 gene mutations.

Characterization of CD4+ T helper cells in patients with Kawasaki disease (KD): preferential production of tumour necrosis factor-alpha (TNF-alpha) by V beta 2- or V beta 8- CD4+ T helper cells

KD is an acute febrile illness in children characterized by coronary arteritis accompanied by aneurysm and thrombotic occlusion. The etiology of KD is unknown. It has been recently reported that KD is associated with the selective expansion of V beta 2+ and V beta 8.1+ T cells in peripheral blood lymphocytes (PBL), by studying the T cell receptor (TCR) repertoire of in vitro activated T cells. KD may therefore be caused by a superantigen [1-3]. To understand better the immunopathology of KD, we investigated TCR V beta 2 and V beta 8.1 expression on both the T cells of freshly isolated PBL and T cell clones (TCC) from patients with KD. Cytokine production by TCC was also studied. Blood samples were obtained from patients with acute (n = 20) and convalescent (n = 20) KD, age-matched children with non-infectious diseases (n = 18), and healthy adults (n = 20). Among these four groups, there were no significant differences in the percentages of either V beta 2+ or V beta 8.1+ T cells of freshly isolated PBL. The same was true for the CD4+ or CD8+ T cell subsets. One hundred and five TCC (98 CD3+ CD4+ CD8- and seven CD3+ CD4- CD8+) established from the affected skin, lymph node or PBL of six patients with KD were also negative for either V beta 2 or V beta 8.1 TCR. Sixty-eight of 105 TCC (65%) produced detectable levels (> 5 pg/ml) of TNF-alpha (6-1016 pg/ml), in the absence of any stimuli. In contrast, only 11 (10%) of 105 TCC or 7 (7%) of 97 TCC produced detectable levels of IL-2 or IL-6, respectively, in the absence of any stimuli. Stimulation with phytohaemagglutinin (PHA) and phorbol myristate acetate (PMA) induced most TCC to produce higher amounts of TNF-alpha, IL-2 and IL-6. These results suggest that CD4+ T helper cells expressing TCR-beta other than V beta 2 or V beta 8 receptor, primarily through TNF-alpha production, are involved in the immunopathology of KD.

[Pharmacokinetic, bacteriological and clinical studies of SY5555 in the pediatric field]

Pharmacokinetic, bacteriological and clinical studies on SY5555, a new oral penem, were carried out, and the following results were obtained. 1. MICs were determined for 6 drugs, SY5555, clavulanic acid/amoxicillin (CVA/AMPC), cefaclor (CCL), cefotiam (CTM), cefpodoxime (CPDX), cefdinir (CFDN) against 20 strains of bacteria isolated from patients who were subsequently treated with SY5555. MICs of SY5555 for Gram-positive cocci ranged from 0.05 to 0.10 microgram/ml against 10 strains of Staphylococcus aureus. The MIC was < or = 0.025 microgram/ml against one strain of Streptococcus pyogenes, and MICs were from < or = 0.025 to 0.39 microgram/ml against Streptococcus pneumoniae. These MIC values were equivalent or superior to those of the other 5 drugs. MICs of SY5555 for Gram-negative bacilli were 0.39 and 6.25 micrograms/ml against Haemophilus influenzae, and these values were equivalent to those of the other drugs, except CPDX. The MIC of SY5555 was 0.39 microgram/ml against 2 strains of Escherichia coli, and this value was equivalent or superior to those of CVA/AMPC and CCL, similar or inferior to those of CPDX and CFDN, and inferior to that of CTM. The MICs of several drugs were determined for 10 strains of Bordetella pertussis and 30 strains of Campylobacter jejuni isolated from patients before this clinical study. The MICs of SY5555 against the 10 strains of B. pertussis were compared with those of 7 drugs, CCL, CTM, CPDX, ampicillin (ABPC), piperacillin (PIPC), imipenem (IPM) and erythromycin (EM). The MIC of SY5555 was 0.78 microgram/ml against all of the strains. This value was superior to those of CCL, CTM and CPDX, similar or inferior to that of IPM and inferior to those of PIPC and EM. The MICs of SY5555 against the 30 strains of C. jejuni were compared with those of 7 drugs. CCL, CTM, CPDX, CFDN, ABPC, IPM and EM, and the MIC of SY5555 was < or = 0.025 microgram/ml or 0.05 microgram/ml and these values were equivalent or superior to those of the 7 reference drugs. 2. SY5555 dry syrup was administered orally at 30 min. after meals, to a total of 5 patients, at doses of 5.0 and 10.0 mg/kg to 2 patients each and at a dose of 15.0 mg/kg to one patient and the plasma concentrations were determined. Peak concentrations were detected 1 to 3 hours after administration in all patients and the peak concentrations were 0.93 and 1.21 micrograms/ml at the 5.0 mg/kg dose, 2.85 and 5.49 micrograms/ml at the 10.0 mg/kg dose and 5.79 micrograms/ml at the 15.0 mg/kg dose.(ABSTRACT TRUNCATED AT 400 WORDS)

Suppression of plasma-activated factor VII levels by warfarin therapy

To investigate the effect of warfarin treatment on the early phase of tissue factor-induced coagulation, we measured plasma-activated factor VII (factor VIIa) levels by a direct fluorogenic assay in 74 cardiovascular disease patients on long-term oral anticoagulation. We divided the patients into three groups based on the international normalized ratio (INR). In the patients with INR ranges of < 1.7 and 1.7 to 2.5, factor VIIa levels were 42% and 61% lower, respectively, than in age- and sex-matched controls. Factor VII coagulant activity (factor VIIc), factor VII antigen (factor VIIag), protein C, and factor X levels were also reduced to a similar extent in both groups. However, in patients with an INR > 2.5, the factor VIIa level was not decreased compared with that at an INR of 1.7 to 2.5, although the factor VIIc, factor VIIag, factor X, and protein C levels were all decreased further. Although the precise relation between the reduction of factor VIIa levels and the increase of INR requires appropriately designed long-term clinical trials, our data suggest that an INR range of 1.7 to 2.5 is sufficient for the suppression of factor VIIa. During the long-term follow-up of three patients with congenital antithrombin III or protein C deficiency, the factor VIIa level was more responsive to changes in the warfarin dose than the INR, and there were generally no corresponding changes of the thrombin-antithrombin III complex (TAT) level. However, one patient showed a transient marked increase of factor VIIa during the discontinuation of warfarin that was accompanied by an increase in TAT. Based on these findings, factor VIIa could be useful for monitoring both hypercoagulable and hypocoagulable states.

Establishment and characterization of an immature human megakaryoblastic cell line, MEG-A2

We have established a novel human megakaryoblastic cell line, designated as MEG-A2, from a patient with megakaryoblastic crisis of Philadelphia (Ph) chromosome positive chronic myelogenous leukemia. MEG-A2 cells showed positive phenotypes for periodic acid Schiff and alpha-naphthylbutyrate esterase reactions, but were negative for myeloperoxidase and naphthol ASD chloroacetate esterase reactions. Flow cytometric analyses of cell surface markers revealed that MEG-A2 cells had a low level of GP IIb/IIIa expression as well as apparent expressions of CD4, CD7, CD13, CD33 and CD34 antigens, but no expression of GP Ib nor glycophorin A. Stimulation with phorbol 12-myristate 13-acetate (PMA) dramatically increased the expression of megakaryocyte-related markers such as HPL-3, J15, Pit-1, Y2/51 and AN51 in MEG-A2 cells. The PMA-stimulation also induced expression of platelet peroxidase (PPO) in MEG-A2 cells on electromicroscopic observation. Proliferative responses to granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) or erythropoietin were observed, and the expression of GP IIb/IIIa was increased by stimulation with GM-CSF, IL-3, erythropoietin and interleukin-6 (IL-6). Protein S mRNA expression was seen in cultured cells on Northern blot analysis. Expression of platelet factor 4 mRNA was induced in PMA-stimulated cells, and a marked accumulation of protein was observed in the culture medium. In conclusion, a new cell line, MEG-A2, belongs to the relatively immature megakaryocytic lineage and has markedly increased megakaryocytic characteristics with PMA stimulation.

Structure and function of beta 2-glycoprotein I: with special reference to the interaction with phospholipid

beta 2-Glycoprotein I (beta 2-GPI) is a cofactor in the recognition of a phospholipid antigen, cardiolipin, by anticardiolipin antibodies in autoimmune diseases such as systemic lupus erythematosus. We examined the interaction of various forms of bovine beta 2-GPI, such as its intact form, desialylated form (Asialo beta 2-GPI), N-terminal domain (domain I) and the modified forms of beta 2-GPI and Asialo beta 2-GPI with nicks in their C-terminal domains (domain 5), with phospholipid liposomes under different conditions of pH and ionic strength. We found that at neutral pH and low ionic strength beta 2-GPI bound to liposome membranes containing cardiolipin with a dissociation constant (Kd) of 10(-8) M. Phosphatidylglycerol, phosphatidylserine, phosphatidic acid or phosphatidylinositol bound to beta 2-GPI, but phosphatidylcholine did not. We also found that domain I and Asialo beta 2-GPI bound to cardiolipin with Kd values of 10(-6) and 10(-8) M, respectively. At neutral pH and both low and high ionic strengths, the affinities of nicked forms of beta 2-GPI and Asialo beta 2-GPI for cardiolipin were lower than those of intact forms but similar to that of domain 1.

Characterization of an inducible P450 hydroxylase involved in the rice diterpene phytoalexin biosynthetic pathway

Ent-isopimara-8(14),15-dien-3 beta-ol (1) was isolated from uv-irradiated rice (Oryza sativa L.) leaves. Since 1 was converted to the rice diterpene phytoalexins and oryzalexins D (ent-isopimara-8(14),15-diene-3 beta,7 alpha-diol) and E (ent-isopimara-8(14),15-diene-3 beta,9 alpha-diol) in uv-irradiated rice leaf microsome fraction in the presence of oxygen and NADPH, it was concluded that 1 was the biosynthetic precursor of these oryzalexins. This enzyme reaction was inhibited by cytochrome P450 inhibitors such as piperonyl butoxide, SKF-525A, paclobutorazole, metyrapone, cytochrome c, and carbon monoxide. The lack of inhibitory activity of 1 for spore germination of Pyricularia oryzae indicates that the final cytochrome P450-dependent hydroxylation steps in converting 1 to oryzalexins D and E are essential for the production of rice phytoalexins with antifungal activities.

Clinical evaluation of pulmonary nodules with single-exposure dual-energy subtraction chest radiography with an iterative noise-reduction algorithm

PURPOSE

To compare the clinical usefulness of the single-exposure dual-energy subtraction method with an iterative noise-reduction algorithm.

MATERIALS AND METHODS

Fourteen radiologists read three sets of images from 44 patients: original computed radiographic images only, original computed radiographic images plus conventional bone-subtracted images, and original computed radiographic images plus iterative noise-reduced bone-subtracted images. Twenty-two patients had one or more (maximum, five) pulmonary nodules; 22 had no pulmonary nodules. Observer performance was evaluated by means of calculation of the average area under the alternative free-response receiver operating characteristic curves (A1).

RESULTS

Compared with the original computed radiographic image only, detection of nodules was significantly better with both the original computed radiographic image plus iterative bone-subtracted image (A1 = 0.72 +/- 0.02 and 0.66 +/- 0.02, respectively; P = .01) and the original computed radiographic image plus conventional bone-subtracted image (A1 = 0.66 +/- 0.02 and 0.61 +/- 0.01, respectively; P = .03).

CONCLUSION

The iterative noise-reduction algorithm is superior to conventional methods in detection of pulmonary nodules.

[Laser bronchoscopic therapy of lung cancer]

Laser endoscopic therapy has now achieved status as an effective treatment modality for lung cancer. The usefulness of Nd-YAG laser as palliative treatment for obstructive tracheobronchial tumors has been recognized. Our experience consisted in 205 YAG laser cases, including 184 obstructive tracheobronchial tumors, and the airway gauge was improved in 88.3%. On the other hand, the effectiveness of photodynamic therapy (PDT) using photofrin as a photosensitizer was demonstrated in our institution in 1979 for the treatment of lung cancers, and increasing attention has focused on this new treatment technique. Over the past decade, 211 patients with central lung cancers, including 66 cases of early-stage lesions, have been treated at Tokyo Medical College Hospital, and a complete remission rate of 65.2% was achieved. We gave an overview of laser endoscopic therapy, including Nd-YAG laser treatment and photodynamic therapy, for lung cancer as well as an evaluation of the effectiveness of these therapies.

Use of high-resolution cytometry in predicting the biologic behavior of T1 adenocarcinoma of the lung

Touch preparations from 60 cases of T1 adenocarcinoma were analyzed using a high-resolution, automated image cytometer. These cases were divided according to pathologic stage: stage I, 31; stage II, 3; stage III, 19; and stage IV, 7. For each nucleus 57 features were analyzed, and using a linear combination of three texture features describing the DNA distribution in the cell nucleus (TARL, ODMAX and FAREA1), aggressive cancer cells belonging to stage III/IV could be identified. The best discrimination between the stages was achieved when the frequency of aggressive cancer cells was 48%; the correct classification rate was 77%. Using this criterion, 22 of 27 patients (81%) who died of cancer within five years after surgery were correctly predicted. These results suggest that high-resolution cytometry may be of value in predicting the biologic behavior of adenocarcinoma cases, especially in stage I/II.

Anti-neutrophil cytoplasmic antibody for proteinase 3 in a child with polyarteritis nodosa

We report a case of a 15 year old boy with polyarteritis nodosa associated with antineutrophil cytoplasmic antibody (ANCA) against proteinase 3 (PR3). After months of steroid and immunosuppressant therapy, the symptoms subsided and the polyaneurysms almost disappeared. The levels of anti-PR3 antibody and of cytokines also decreased. The results indicate that ANCA is a good indicator of this disease activity, and may play some pathogenic role in the disease.

Expression of inhibin alpha, and beta A subunit and activin type II receptor mRNAs in various human pituitary adenomas

Inhibin and activin are known to be involved in the pituitary hormone secretion as well as proliferation of the pituitary. We studied the expression of inhibin alpha, and beta A subunit and activin type II receptor (ACTR 2) mRNAs in human pituitary adenomas to determine the significance of inhibin and activin in pituitary hormone secretion. Tumor tissues were homogenized immediately after resection in guanidinium thiocyanate to extract total RNA. PCR was performed with reversely transcripted cDNA and respective amplification primers. DNA bands obtained for inhibin alpha, beta A and ACTR 2 by agarose gel-electrophoresis were 367, 285, and 389 bp, respectively. Messenger RNAs for inhibin beta A were demonstrated in all of the pituitary tissues studied, namely in 3 GH, 2 ACTH, 6 PRL and 1 FSH producing adenomas and 17 non-functioning adenomas. Inhibin alpha mRNAs were detected in 10 of 12 functioning adenomas and 15 of 17 non-functioning adenomas. ACTR 2 mRNAs were found in 11 out of 17 non-functioning adenomas, but only found in 3 out of 12 functioning adenomas. These results suggested local production of activin, a homodimer of beta-subunits, and inhibin, a heterodimer of alpha and beta subunits, in most of the pituitary adenomas regardless of their hormone secretion. On the other hand, a significantly higher incidence of ACTR 2 in non-functioning adenomas than in functioning adenomas suggested that activin had its main site of action in non-functioning adenomas, which could be potential gonadotropinomas.

Effects of brain (B-type) natriuretic peptide on coronary artery diameter and coronary hemodynamic variables in humans: comparison with effects on systemic hemodynamic variables

OBJECTIVES

This study attempted to clarify the effects of human brain (B-type) natriuretic peptide on coronary artery diameter and coronary vascular resistance in humans.

BACKGROUND

Brain natriuretic peptide induces vasodilation in systemic circulation by activating particulate guanylate cyclase of the vascular smooth muscle.

METHODS

In 13 patients with normal coronary arteries and left ventricular function, brain natriuretic peptide was infused at 0.5 microgram/kg body weight per min for 4 min into the left main coronary artery (six patients, Group A) or into the pulmonary artery (seven patients, Group B). Systemic hemodynamic variables and coronary sinus blood flow were measured before and after the infusion. The lumen diameter of the left coronary artery was quantitatively measured.

RESULTS

In both groups, brain natriuretic peptide significantly increased heart rate and decreased mean arterial pressure. Rate-pressure product remained unchanged in both groups. Brain natriuretic peptide decreased systemic vascular resistance index significantly in both groups (both p < 0.01 vs. baseline), and there was no difference in the effect between the groups. Brain natriuretic peptide decreased coronary vascular resistance in Group A (p < 0.01 vs. baseline) but did not affect coronary vascular resistance in Group B (p < 0.01 vs. Group A). The lumen diameters of the proximal and distal segments of the left coronary artery were increased significantly after brain natriuretic peptide in both groups. After infusion of brain natriuretic peptide, mean plasma level of brain natriuretic peptide in the coronary sinus increased from 36 to 130,411 pg/ml in Group A and from 64 to 12,329 pg/ml in Group B.

CONCLUSIONS

Brain natriuretic peptide shows a vasodilator effect on the coronary artery system in humans. However, the effect does not appear uniformly but is seen preferentially in the epicardial coronary artery. The sensitivity of the coronary resistance vessels to brain natriuretic peptide is low compared with that of the resistance vessels of the systemic circulation.

Skeletal manifestations in Fryns syndrome

We report on a female baby with Fryns syndrome who died soon after birth. The patient had short limbs, coarse face, hypoplastic lungs, diaphragmatic hernia, and acral hypoplasia. Literature review disclosed varying degrees of skeletal manifestations in Fryns syndrome; short limbs may be a component of Fryns syndrome.

Rolipram, a cyclic AMP-selective phosphodiesterase inhibitor, reduces neuronal damage following cerebral ischemia in the gerbil

We examined the effects of rolipram, a cyclic AMP-selective phosphodiesterase inhibitor, on cerebral ischemia-induced neuronal damage in Mongolian gerbils. Transient forebrain ischemia was induced by 3-min occlusion of bilateral common carotid arteries. Rolipram, at a dose of 0.3 or 3 mg/kg, was injected i.p. 30 min before ischemia. Histopathological observations showed that neuronal damage to the hippocampal CA1 subfield, which was seen 7 days after ischemia in vehicle-treated animals, was reduced in animals treated with the higher dose of rolipram.

Voltage-gated Ca2+ channel blockers, omega-AgaIVA and Ni2+, suppress the induction of theta-burst induced long-term potentiation in guinea-pig hippocampal CA1 neurons

It is widely believed that a rise in post-synaptic calcium concentration ([Ca2+]i) is a necessary step in the induction of long-term potentiation (LTP) (Bliss and Collingridge, Nature, 361 (1993) 31-39). In this experiment, we examine the involvement of voltage-gated Ca2+ channels (VGCC) in the induction of AP5-sensitive LTP induced by theta-burst stimulation in guinea-pig hippocampal CA1 neurons. The VGCC blockers, Ni2+ (25 microM, T-channel blocker) or omega-AgaIVA (60 nM, P-channel blocker), which have no effect on synaptic transmission, suppress 60% or 78% of the theta-burst induced LTP, respectively. This implies that Ca2+ entry through VGCC is an important step in this form of LTP.

CD8+ T cells specific to the exogenous antigen. Mode of antigen recognition and possible implication in immunosuppression

This study demonstrates and characterizes CD8+ T cells specific to the exogenous Ag, bovine alpha s1-casein. Purified CD8+ T cells from alpha s1-casein-primed lymph node cells proliferated well in response to an alpha s1-casein derivative, trypsin-digested alpha s1-casein. CD8+ T cell repertoire for the exogenous Ag was directly demonstrated in the primary culture condition. The intact alpha s1-casein primed the responding CD8+ T cells in vivo more efficiently than the tryptic alpha s1-casein; however, the in vitro proliferative response by the intact alpha s1-casein was weaker than that of the tryptic alpha s1-casein. CD8+ T cells recognized the exogenous Ag in association with MHC class I molecules as revealed by an Ab-blocking study. The major immunodominant region for the CD8+ T cells was mapped to region 136-151 of alpha s1-casein, and peptide 136-151 primed the responding CD8+ T cells but not any CD4+ T cells. Peptide 136-151 is the CD8+ T cell-specific determinant. Upon antigenic stimulation, the exogenous Ag-specific CD8+ T cells produced a significant level of IFN-gamma, which has immune suppressive activity for IgE synthesis. Our study strongly implies that CD8+ T cells that proliferate and produce IFN-gamma in response to the exogenous Ag would play a vital role in Ag-specific immunosuppression.

A clinical and immunohistochemical study of papillary adenocarcinoma of the prostate

Clinical and immunohistochemical studies were conducted to evaluate prostatic papillary adenocarcinoma and prostatic papillary hyperplasia. Subjects consisted of 5 cases of papillary adenocarcinoma and 2 cases of papillary hyperplasia. There is no conclusive clinical factor for preoperative diagnosis, but we attach importance to endoscopic findings. PSA, PAP, high molecular weight cytokeratin, and PCNA were evaluated immunohistochemically. PSA became positive in every instance but one--a case of papillary adenocarcinoma which became +/-. PAP was + in all cases, except for 1 case of papillary adenocarcinoma. Basal cells were positive for high molecular weight cytokeratin in 2 cases of papillary hyperplasia but were missing in papillary adenocarcinoma. Although PCNA was free from positive nuclei in papillary hyperplasia, positive nuclei were found in all cases of papillary adenocarcinoma. Considering these immunohistochemical results, papillary adenocarcinoma can be said to originate in the glandular epithelium of the prostate, as does ordinary prostatic carcinoma.

Immunohistochemical localization of superoxide dismutase in the hippocampus following ischemia in a gerbil model of ischemic tolerance

Pretreatment of the gerbil brain with a 2-min period of sublethal ischemia protects against neuronal damage following a subsequent 3-min period of ischemia, which normally destroys pyramidal neurons in the CA1 region of the hippocampus. To clarify the role of superoxide dismutase (SOD) in this ischemic tolerance, we immunohistochemically investigated the alterations in copper-zinc SOD (CuZnSOD) and manganese SOD (Mn-SOD) in the gerbil hippocampus following 3-min ischemia with or without the first mild ischemia. Normal hippocampus showed an intense CuZnSOD immunostaining in pyramidal neurons but relatively less MnSOD immunostaining. MnSOD, but not CuZnSOD, immunoreactivity increased after the first ischemia. Both CuZnSOD and MnSOD immunoreactivities decreased throughout the hippocampus 4 h after 3 min of ischemia both with and without the first ischemia. The immunostaining recovered in resistant regions (CA3 and dentate gyrus) after 1 day in both groups and in the pretreated CA1 after 2 days. Without pretreatment, however, the immunostaining never recovered in the vulnerable CA1 region. The results suggest that ischemic tolerance is induced in part by enhanced synthesis of MnSOD in the tolerance-acquired hippocampus. Both CuZnSOD and MnSOD immunoreactivities decreased after the second ischemia even in the pretreated hippocampus in the early reperfusion periods, but ischemic tolerance facilitated the recovery from the postischemic reductions in SOD immunoreactivity.

Catheter-related infections by Hansenula anomala in children

During August and September, 1992, we experienced 4 cases of Hansenula anomala (H. anomala, synonym Pichia anomala) fungemia in immunocompromised patients. Two patients had been suffering from a malignant disease, 3 of them had received broad-spectrum antibiotics and a central venous catheter (CVC) had been inserted in all of them. H. anomala was isolated as the sole pathogen from all 4 patients. Three of them responded favorably to fluconazole after withdrawal of the catheter, but one failed. H. anomala should be considered as a possible cause of catheter-related infections.