Complementary DNA sequence encoding the major neural cell adhesion molecule isoform in a human small cell lung cancer cell line

The neural cell adhesion molecule (N-CAM), a member of the immunoglobulin gene super-family mediating homophilic cell-cell adhesion in a neuroendocrine system, is preferentially expressed in human small cell lung cancer (SCLC). Immunoprecipitation of a panel of SCLC cell lines by monoclonal antibodies (mAbs) specific for N-CAM detects mainly the 145-kDa isoform. This result was correlated with Northern blotting where a single 6.2-kb mRNA was detected in nine SCLC cell lines. To determine cDNA sequence encoding the N-CAM isoform, we selected several cDNA clones encoding N-CAM isolated from OS2-R, a SCLC cell line established in our laboratory. Based on the analysis of the full-length cDNA obtained from two clones, the sequence of this 145-kDa isoform was shown to be essentially identical to that of the 140-kDa N-CAM isoform of neuroblastoma except for a single base pair changed at position 1620 without changing amino acid encoded.

What effect can rhythmic finger tapping have on the phonological similarity effect?

The effects of rhythmic finger tapping on the phonological similarity effect were investigated in two experiments. In both, subjects were tested for serial recall of visually presented letter sequences that were either phonologically similar or dissimilar. The letter sequences had to be remembered under three tapping conditions: right-hand tapping, left-hand tapping, and a no-tapping control. Experiment 1 showed clear phonological similarity effect in both the control and the left-hand tapping conditions, but not in the right-hand tapping condition, when recall responses were written with the right hand. When the number of tapping practice trials was fixed at two and recall was vocal in Experiment 2, the phonological similarity effect was eliminated in both the right-hand and the left-hand tapping conditions. These results suggest that some form of speech motor programs played an important role in serial recall.

Microwave ablation of the atrioventricular junction in vivo and ventricular myocardium in vitro and in vivo. Effects of varying power and duration on lesion volume

Catheter ablation in ventricular tachycardia has achieved only limited success using direct current (DC) and radiofrequency (RF) energy, due to either high complication rates or a limited lesion size. Microwave energy represents a possible alternative source of energy for percutaneous ablation of the ventricular myocardium. However, an optimal method for titration of the dose of microwave energy to achieve the desired lesion volume has not yet been established. The safety and efficacy of microwave ablation of the atrioventricular (AV) junction were studied in 11 dogs in vivo. The relationship between lesion size following microwave ablation and the power output of or exposure duration to microwave energy was also examined at disparate sites in each superfused left ventricular epicardium in vitro. To observe the pathologic changes in the myocardium after microwave ablation, microwave ablation of the endocardium of the left ventricle was carried out in 9 dogs in vivo. Complete AV block was achieved in 10 of the above 11 dogs with a mean of 5 applications of microwave energy. The lesion volume in vitro demonstrated a parallel increase with power (r = 0.76) and duration (r = 0.81). The mean lesion volume at 30 sec was: at 10W, 0.8 +/- 1.6; 20 W, 34.7 +/- 10.3; 30 W, 34.7 +/- 22.4: 40 W, 64.7 +/- 64.4; 50 W, 87.2 +/- 42.3; 60 W, 85.8 +/- 38.1; 70 W, 124.7 +/- 36.5; 80 W, 134.2 +/- 49.0 mm3. The mean lesion volume at 80 W was: at 15 sec, 32.6 +/- 37.8; 30 sec, 101.2 +/- 46.4; 60 sec, 180.6 +/- 80.1; 120 sec, 291.8 +/- 122.7; and 180 sec, 459.3 +/- 204.6 mm3. The ablated lesions showed discrete, homogeneous coagulation necrosis with sharp margins from the adjacent normal myocardium. Microwave energy may thus be more effective than RF energy, and have a lower risk of complications and arrhythmogenesis than DC energy when used for ablation in ventricular tachycardia.

Molecular cloning and sequencing of porcine somatostatin receptor 2

The porcine somatostatin receptor gene was isolated from a porcine genomic library. Based on the deduced amino acid sequence, this gene encodes a 369 amino acid protein with seven hydrophobic segments, a characteristic of G-protein coupled receptors, and shows only 13 amino acid difference (identity 96.5%, similarity 99.2%) in amino acid sequence from human somatostatin receptor 2. The data indicate that the amino acid sequence is highly conserved in pig, human, rat and mouse somatostatin receptor 2.

Common tetrasaccharide epitope NeuAc alpha 2-->3Gal beta 1-->3(Neu-Ac alpha 2-->6)GalNAc, presented by different carrier glycosylceramides or O-linked peptides, is recognized by different antibodies and ligands having distinct specificities

A novel globo-series disialoganglioside, disialosyl galactosyl globoside (Structure 1 below), defined by new monoclonal antibody (mAb) RM2, was isolated and characterized as having terminal structure identical to that of ganglio-series ganglioside GD1 alpha (Structure 2) and a common mucin-type epitope (Structure 3) widely distributed in glycoproteins such as glycophorin A. While these three structures share a common nonreducing tetrasaccharide terminus, mAb RM2 showed strong specific reactivity only with Structure 1, not with Structures 2 or 3. Another mAb, QSH2, reacted strongly with Structure 3 but did not cross-react with Structures 1 or 2. Conformational molecular models based on minimum energy hard sphere exoanomeric calculations suggest that Structure 1 presents a unique surface topology distinct from that of Structures 2 or 3. Our findings suggest the novel concept that reactivity of a common carbohydrate epitope with different antibodies or ligands is highly dependent on the type of carrier glycosylceramide or carrier O-linked peptide. [formula: see text]

Spinal epidural hematoma with spontaneous recovery demonstrated by magnetic resonance imaging

The authors report the sixth case of spinal epidural hematoma with spontaneous recovery, which was demonstrated on serial magnetic resonance images. These images showed the course and plausible mechanism of disappearance of the hematoma.

Ultrastructural localization of myoglobin mRNA in human skeletal muscle

The intracellular localization of myoglobin mRNA in the skeletal muscles of normal subjects was examined by in situ hybridization using a biotin-labeled cDNA probe. By phase-contrast microscopy, myoglobin mRNA signals were demonstrated to be located preferentially on the A-band. Two different methods of tissue preparation, i.e., pre-embedding method and post-embedding method, were used for the electron microscopic study. With the pre-embedding method, only a few gold particles were found to be associated with cytoskeletal filaments in the intermyofibrillar space. With the post-embedding method, superior preservation of sections and higher signal intensities were obtained. Although most of the gold particles were localized on the A-band, some were seen in other regions; i.e., in the intermyofibrillar space, perinuclear space, or the I-band, where myoglobin is localized. These findings suggest that myoglobin is primarily synthesized on the A-band, where ribosomes predominantly exist, although myoglobin is also localized on the I-band. The predominant localization of myoglobin mRNA on the A-band may aid in the mRNA transcription and may be related to the regulation of myoglobin synthesis in skeletal muscle cells.

[Microvascular mechanisms of change in tumor blood flow elicited by vasopressors]

To elucidate the microvascular mechanisms of change in tumor blood flow due to vasopressors (angiotensin II, epinephrine, methoxamine), we analyzed the site of vascular resistance (VR) increased by each vasopressor. Arteriolar vessels within a transparent rat chamber were classified centripetally (a2-a5) according to Strahler's nomenclature. Vessels that feed into the tumor microcirculation were a2 modified by the tumor (starting vessels). Under angiotensin II (A II)-induced hypertension, the pressure of all arteriolar vessels increased roughly in proportion to the increase in mean arterial blood pressure. The greatest pressure drop and hence the most resistance due to A II occurred across the a2. During epinephrine-induced hypertension, there were major pressure drops between a4 and a3, and between a3 and a2. The amount of contraction of arteriolar vessels due to methoxamine was much smaller than that due to epinephrine, and the pressure increase in a4 and a3 was also small. From the facts described above, we may conclude as follows: A II creates greater vascular resistance of a2 vessels to blood flow and also greater perfusion pressure of a5-a3 vessels, resulting in increased blood inflow into a starting vessel which then becomes a passive vessel. Epinephrine causes an increase in the resistance of a3, a4 and probably upstream from a4 arterioles to blood flow. Thus, tissue blood flow in subcutis and tumor almost always decreases together. The fact that tissue blood flow in normal subcutis and tumor did not change significantly under methoxamine-induced hypertension is probably due to the results that methoxamine had little effects on the vascular resistance of smaller arterioles to blood flow.

Protein S Tokushima: abnormal molecule with a substitution of Glu for Lys-155 in the second epidermal growth factor-like domain of protein S

A 29-year-old female patient with heterozygous congenital protein S deficiency suffering from thrombotic disease had normal levels of both total and free protein S antigen (70% and 65%, respectively), but low cofactor activity (31%) for activated protein C, indicating that she had a variant of protein S, protein S Tokushima. Western blotting using the polyclonal anti-protein S antibody showed that approximately half of the patient's protein S appeared to be the variant with a higher molecular weight than normal protein S. The partially purified variant protein S bound neither to the monoclonal antibody recognizing calcium-dependent conformation of protein S nor to the antibody recognizing the thrombin-sensitive domain of protein S. Among the exons from II to XV of the patient's protein S gene encoding from the NH2-terminal end to the COOH-terminal end of protein S, only one missense mutation (A to G) was found in exon VI of the protein S alpha-gene, which results in amino acid substitution of Glu(GAG) for Lys-155(AAG) in the second epidermal growth factor-like domain of protein S. The recombinant protein S Tokushima expressed in BHK cells had a slightly higher molecular weight than the recombinant normal one, did not bind to the antibody specific for the thrombin-sensitive domain, and did not show the cofactor activity. These findings suggest that the protein S Tokushima molecule is structurally and functionally a variant of protein S, and that this variant protein S is the cause of severe thrombosis in this patient.

Unresponsiveness of antidonor cytotoxic T cells in a long-term stable renal transplant recipient

The antidonor immune response was examined in a one haplotype-mismatched renal transplant recipient with an allograft that had been well-functioning for more than 10 years. Although the relative response of the mixed lymphocyte reaction (MLR) was (45.8)% and the MLR responder cells stimulated by donor cells produced measurable amounts of interleukin-2 (IL-2) (11.6 U/ml), the cytotoxic T lymphocytes (CTL) could not be generated against donor cells, even with exogenous IL-2. These results indicate that antidonor CTL precursors were either deleted or inactivated in this recipient.

Immunohistochemical study of graft-versus-host reaction (GVHR)-type drug eruptions

Skin biopsies of graft-versus-host reaction (GVHR)-type drug eruptions in the acute phase were compared immunohistochemically with those in the chronic phase and also with non-GVHR type drug eruptions in the acute phase. Predominance of CD8+ T cells in the epidermal infiltrates, reduction in the number of epidermal OKT6+ dendritic cells (Langerhans cells), and increased expression of HLA-DR and ICAM-1 on keratinocytes were observed in the acute phase of GVHR-type, but not in either the chronic phase of GVHR-type or the acute non-GVHR type. These findings were similar to those of previous reports on skin lesions of acute GVH disease (GVHD) seen after bone marrow transplantation. Therefore, immunohistochemistry is not useful for differential diagnosis between acute GVHR-type drug eruptions and acute cutaneous GVHD. These findings also indicate that similar immunomechanisms may be involved in the pathogenesis of both GVHR-type drug eruptions and cutaneous GVHD.

[Rescue effect of 15-deoxyspergualin for acute rejection on heart transplantation--using a rat model]

15-Deoxyspergualin (DSG) attracts a lot of attention as an immunosuppressive drug which has less side effects these days. In the present study, we researched the rescue effect of DSG for acute rejection on heart transplantation (HTX) by using rat models. We performed 40 heterotopic heart transplantation models. We injected them DSG (group A: 5 mg/kg/day, group B: 10 mg/kg/day) intravenously through 3 days, starting from the 3rd day the 4th day, and the 5th day after HTX. Our previous study showed the pathology on the 3rd day after HTX corresponded to mild rejection, the 4th day to moderate rejection, and the 5th day to severe rejection. One day after the injection was completed, the recipients were sacrificed. The rescue effect was histopathologically assessed by H-E stain, and the action mechanism of DSG was considered by immunohistochemical stain using monoclonal antibodies, which were against CD4 positive cells, CD8 positive cells, and macrophages. In result, the rescue effect of DSG was significant in all groups, in comparison with controls, which had no immunosuppression. And the rescue effect of group B was superior to group A. We also found using a immunohistochemical technique, that DSG inhibited the accumulation of CD4 and CD8 positive cells. We concluded the rescue effect of DSG for acute rejection on HTX was significant, especially in 10 mg/kg/day even in the severe rejection. And the suppression of helper and cytotoxic T cells accumulation might be one of the action mechanisms of DSG.

Physiological indices of visual fatigue due to VDT operation: pupillary reflexes and accommodative responses

In spite of the clarification of some significant physiological factors of visual fatigue caused by VDT work, pupillary reflexes have not been studied as to how they are affected after prolonged visual work. This study examined visual function changes objectively in terms of pupillary reflexes and lens accommodative responses after a 4-hr VDT operation task. The relationship between the two functions was also examined. Two measurements in this paper revealed the physiological function changes due to VDT operation. The subjects involved were five students with an average age of 22.6 years. First, near-reflex measurement ascertained decreases in amplitude and the velocity of accommodation function after the visual task. Second, light-reflex measurement revealed a delay of the reflex, an increase in the amplitude of the reflex, and a decrease in pupil size after the visual task. A weak correlation between the decrease in pupil size and accommodation function was found. The occurrence of visual fatigue due to 4-hr VDT operation was also confirmed by CFF measurements and reported subjective visual symptoms in this experiment.

Preferential induction of IL-4 is determined by the type and duration of antigenic stimulation

The transition of lymphokine production from IL-2 to IL-4 was investigated with antigen-primed lymph node cells (LNC) by observing cytokine release following sequential cycles of antigen exposure in vitro. LNC from mice infected with Nippostrongylus brasiliensis (Nb), Trichinella spiralis, or primed with giant ragweed pollen demonstrated a pattern of dominant IL-2 production at 24 hr; however, there was a switch to predominantly IL-4 production within 72 hr following the first cycle of in vitro antigenic stimulation. In addition, repeated antigenic stimulation with these antigens shifted the pattern to IL-4 production. In contrast, only IL-2 production was observed after a single cycle of in vitro antigenic challenge with haptens (e.g., NP-O-succinimide or trimethylammonium hapten) or the naive allogenic spleen cells. Thereafter, the lymphokine production pattern gradually changed from IL-2 alone to mixtures of IL-2 and IL-4, and finally to predominant IL-4 secretion. In contrast, following priming with purified protein derivatives (PPD), it was difficult to detect IL-4 release even after nine successive weekly stimulations. However, activation of PPD-primed cells with anti-CD3 antibody resulted in IL-4 secretion. Furthermore, Nb-primed T cells, which produced IL-4 alone after repeated antigenic stimulation, produced IL-2 when stimulated in the presence of cycloheximide. These results suggest that (1) immune populations regulate cytokine production, (2) the IL-2/IL-4 profile is dependent on the type and duration of antigenic stimulation, and (3) production or accumulation of cycloheximide-sensitive proteins is critical for the switch from IL-2 to IL-4 secretion.

Enhanced secretion and impaired natriuretic action of atrial natriuretic peptide in response to hypertonic saline infusion in patients with essential hypertension

To clarify the natriuretic action of endogenous atrial natriuretic peptide (ANP) in patients with essential hypertension (EHT), we examined the relationship between ANP release and urinary sodium excretion in response to hypertonic saline infusion. Plasma ANP levels increased from 13.3 +/- 2.0 pg/ml to 37.0 +/- 3.0 pg/ml in patients with EHT and from 9.2 +/- 1.5 pg/ml to 21.1 +/- 4.0 pg/ml in normal subjects after the infusion. The area under the curve (AUC) of plasma ANP response was significantly higher in patients with EHT than in normal subjects (P < 0.05). There was a significant positive correlation between AUC and urinary sodium excretion in both groups (P < 0.01). However, the ratio of urinary sodium excretion to AUC was significantly lower in patients with EHT than in normal subjects (P < 0.01). These results suggest that impaired natriuretic response to endogenous ANP is one of the factors responsible for the development of EHT and that enhanced secretion of ANP in response to hypertonic saline infusion is a compensatory mechanism to the impaired natriuretic action of ANP in patients with EHT.

The influence of intravenous immunoglobulin treatment on maternal immunity in women with unexplained recurrent miscarriage

PROBLEM

Recently the protective value of high-dose intravenous immunoglobulin (IVIG) in the treatment of unexplained recurrent miscarriage has been reported to be similar to that of conventional immunotherapy with paternal leukocytes. We examined the effect of IVIG treatment on the cellular and humoral level of maternal immunity to demonstrate the possible mechanism by which IVIG might act to prevent recurrence of pregnancy loss.

METHOD

Eight patients were treated with a 20- to 25-g dose of IVIG every 2 to 3 wk during their first-trimester pregnancies. The development of anti-idiotypic autoantibodies against maternal T-cell receptors, maternal anti-paternal lymphocyte antibodies detected by flow cytometric crossmatch, and changes of maternal lymphocyte subpopulations were monitored before pregnancy and then weekly during IVIG treatment.

RESULTS

Five of eight patients gave birth successfully after IVIG treatment given during the first trimester of pregnancy (success rate: 62.5%). Although we could not demonstrate a general immunological effect of IVIG on maternal immunity in vivo, a few significant changes of immunological parameters were found in some patients.

CONCLUSION

Our results suggest that the effect of IVIG on maternal immunity is not a passive increase of blocking antibody including anti-HLA antibody or modification of maternal T-cell subsets but, more likely, a passive increase of anti-idiotypic antibody against anti-HLA antibody or soluble HLA antigens. However, whether the immunomodulating effect of IVIG is related to its possible mechanism to prevent abortion remains unestablished.

Expression of granulocyte colony-stimulating factor and its receptor at the fetomaternal interface in murine and human pregnancy

Granulocyte colony-stimulating factor (G-CSF) is a cytokine which regulates proliferation and differentiation of neutrophilic granulocytes, and its receptor (G-CSF-R) is a member of the hemopoietic growth factor receptor family. We studied the expression of G-CSF and G-CSF-R at the fetomaternal interface in murine and human pregnancy. Immunohistochemical analysis and in situ hybridization indicated that both G-CSF and G-CSF-R are expressed in mouse spongiotrophoblasts and placental labyrinths, and human placental cytotrophoblasts and syncytiotrophoblasts. They were also detected in mouse decidual basalis cells and endometrial epithelial cells, and human decidual stromal cells and endometrial gland cells. These results suggest that G-CSF plays a role in decidual and placental functions by autocrine and paracrine mechanisms.

Identification of causative chemicals of allergic contact dermatitis using a combination of patch testing in patients and chemical analysis. Application to cases from rubber footwear

5 cases of allergic contact dermatitis from rubber footwear were investigated by a combination of patch testing in patients and chemical analysis of causative rubber products. Our studies revealed 2-mercaptobenzothiazole (MBT) and benzothiazyl disulfide (MBTS) (typical allergenic accelerators) as causative chemicals in 3 cases from children's rubber shoes, ladies' rubber boots and ladies' canvas shoes. These 3 patients reacted to mercaptobenzothiazole-type accelerators including MBT and MBTS. MBT and MBTS were determined in each item of causative footwear by chemical analysis, including extraction by shaking with acetone-chloroform (1:1) mixture at room temperature and determination using reversed-phase high-performance liquid chromatography (RP-HPLC). Subsequently, we identified styrenated phenol (SP), a newly found allergenic antioxidant, as a causative chemical in a case from ladies' canvas shoes. The patient reacted to SP but not to MBT and MBTS, though SP, MBT and MBTS were determined in the causative shoes by gas chromatography (GC), GC-mass spectrometry (GC-MS) and HPLC. We also identified p-tert-butylphenol-formaldehyde resin (PTBP-F-R), (a known allergenic adhesive ingredient) as a causative chemical in a case from ladies' sneakers. The patient reacted to PTBP-F-R but not to p-tert-butylphenol (PTBP), MBT and MBTS. These 4 compounds were determined in the causative sneakers by GC, GC-MS and HPLC. Thus, our studies revealed that not only known allergens, such as MBT, MBTS and PTBP-F-R, but also a newly found one, such as SP, were important causes of allergic contact dermatitis from rubber footwear.

[Discriminative analysis of dependent elderly between home care and institutionalized groups in Sendai]

Public health and welfare services were examined in 125 dependent elderly aged 70 to 89 years old from a randomly selected population of 1,249 from 3 different areas (central, residential and suburban) in Wakabayashi-ku, Sendai. Of the 125 dependent elderly, 91 (72.8%) were being cared for at home (the home group), and 34 (27.2%) were in hospitals or nursing homes (the resident group). Multivariate analyses using Hayashi's quantification method II were conducted for a comparison between the home group and the resident group. For the resident group relationships were found to "not having any family members to live with", and to "severe disability in ADL". Of the 91 subjects in the home group, 27 (29.7%) were visited by public health nurses (the visited group), and 64 (70.3%) were not (the not-visited group). Multivariate analyses using Hayashi's quantification method II were conducted for a comparison between the visited group and the not-visited group. For the visited group relation to husbands or wives being caregivers and to severe disability in ADL was found. Of the 91 in the home group, 15 (16.5%) received welfare services (the recipient group), and 76 (83.5%) did not (the non-recipient group). Again, multivariate analyses using Hayashi's quantification method II were conducted for a comparison between the recipient group and the non-recipient group. In the non-recipient group a relationship to not having caregivers or to caregivers being persons other than husbands, wives, children or grandchildren was seen.

Purification of Gnathostoma spinigerum larval antigens by monoclonal antibody affinity chromatography

An immunoaffinity column was prepared by coupling a partially purified Gnathostoma spinigerum-specific IgG1, MAb SK-6C4 (5 mg/ml) to CNBr-activated Sepharose 4B. Ten milliliters of approximately 0.3 mg/ml of crude soluble G. spinigerum larval antigens (GsAL3) were loaded onto the affinity column at a flow rate of about 5 ml/hour. Elution of the bound antigens was accomplished using 50 mM diethylamine-HCI containing 0.15 M NaCL, pH 11.5. The average amount of eluted antigens obtained by one passage of crude GsAL3 (1-4 mg) through 4 to 8 ml of column matrix was 143 micrograms (range, 67 - 414 micrograms). The minimal amount of purified GsAL3 detectable by ELISA using MAb SK - 6C4 (100 micrograms/ml) was 50 ng/ml. The SK - 6C4 affinity-purified GsAL3 was found to be relatively pure and immunologically specific as determined by SDS-PAGE and Western blotting, respectively.

Effects of inhalational anesthetics on biochemical events in growing neuronal tips

BACKGROUND

The influence of general anesthetics on developing organs has been a source of concern for many years. The central nervous system, which is developing rapidly at the time of birth, is of special interest in this regard. In this study, the biochemical characteristics of developing neural tips (growth cones) were examined after exposure to anesthetics to elucidate the molecular mechanism by which long-lasting alterations in the nervous system, including neuroteratogenicity, as previously described, were evoked.

METHODS

Neonatal rats were exposed to an atmosphere containing inhalational anesthetics (1% halothane or 75% nitrous oxide) or a control atmosphere (25% O2 and 75% N2) for 6 h at postnatal day 1. After this exposure, growth cone particles were isolated from the forebrain using a recently devised cell fractionation method at postnatal days 2, 3, 4, and 5. Protein composition, phosphoprotein patterns, and protein kinase C (PKC) activities of the isolated growth cones were compared between each group exposed to anesthetics and the control group. The dose-response relationship of the action of anesthetics on PKC activity was also examined (at 0.5 and 0.75% halothane and 25 and 50% N2O).

RESULTS

The increase in body weight and brain wet weight were not significantly affected by exposure to either anesthetic. No apparent influence on protein composition was observed by sodiumdodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). However, calcium-dependent protein phosphorylation of the 46 kDa protein and of the 80 kDa protein, which is reported to be mediated by PKC, were significantly reduced after exposure to the anesthetics. A direct assay of PKC activity in growth cone particles indicated that PKC activity in the growth cone was 70.6 +/- 9.6% of the control value at 24 h after exposure to 1% halothane, and 63.2 +/- 4.9% after exposure to 75% nitrous oxide. Exposure to 0.75% halothane or 50% nitrous oxide had a similar, but lesser, effect on this parameter. In contrast, exposure to 0.5% halothane or 25% nitrous oxide evoked no apparent effect. Thus the PKC activity in growth cone particles, which is thought to play an important role in signal transduction in the developing brain, was shown to be affected by exposure to inhalational anesthetics over a range of concentrations.

CONCLUSIONS

Considering the crucial role of growth cones in the establishment of the neuronal network, the interruption of signal transduction in the growth cone at a time that is critical in directing the neurite extension may evoke a long-lasting alteration in the neural network. Therefore, the effect of inhalational anesthetics on the growth cone enzyme observed in this study may have a major role in the mechanism that induces morphologic or behavioral neuroabnormalities in later life.

[Helicobacter pylori and the development of atrophic gastritis]

A close relationship between H. pylori infection and atrophic gastritis has been reported, and atrophic gastritis has been thought of as one of the precursors of gastric carcinoma. It was reported that there was a significant positive correlation between the reduction of serum pepsinogen (PG) I/II ratio and the progression of atrophic gastritis. The ratio of PG I/II was significantly decreased in H. pylori positive patients when compared to H. pylori negative patients with chronic gastritis. The PG I/II ratio in gastric cancer was significantly lower than that of chronic gastritis, while the prevalence of H. pylori was not significant difference between gastric carcinoma and chronic gastritis. It is suggested that there is strong correlation between H. pylori infection and the development of atrophic gastritis, and that eradication of H. pylori from gastric mucosa might reduce the risk of developing gastric carcinoma.

[Helicobacter pylori and urease activity--comparative study between urease positive and negative mutant strains]

The ammonia concentration in the gastric juice from H. pylori positive cases was significantly higher than that from negative cases, and there was positive correlation between number of H. pylori, gastritis score and ammonia concentration in gastric juice. It is suggested that ammonia in gastric juice which is produced by powerful urease activity of H. pylori is one of the pathogenic factors in gastritis. We succeeded in producing a urease-negative mutant strain of H. pylori. This strain did not colonize gastric mucosa of Cynomolgus monkeys. H. pylori survival time in vitro was increased at pH 2.0 in the presence of urea. These results suggest that urease facilitates colonization of gastric mucosa by H. pylori, and prolongs the survival of H. pylori in an acidic environment.

The effect of interleukin 2 and transforming growth factor-beta 2 (TGF-beta 2) on the proliferation and natural killer activity of decidual CD16- CD56bright natural killer cells

The present study, using flow cytometry, demonstrated that CD16- CD56bright natural killer (NK) cells, which are abundant in the decidua, have both interleukin-2 receptor alpha (IL-2R alpha) and interleukin-2 receptor beta (IL-2R beta). The NK activity and DNA synthesis of CD16- CD56bright NK cells were markedly elevated even by treatment with small amounts of IL-2. These results indicate that decidual CD16- CD56bright NK cells possess a high-affinity receptor for IL-2. Transforming growth factor-beta 2 (TGF-beta 2), which is contained in the decidua and is thought to serve as a major immunosuppressive factor, reduced the NK activity of decidual CD16- CD56bright NK cells, but it hardly affected the IL-2-induced augmentation of the NK activity or DNA synthesis of decidual CD16- CD56bright NK cells. The conclusion has therefore been reached that once IL-2 is produced in the decidua, the IL-2-induced potentiation of the NK activity of decidual CD16- CD56bright NK cells cannot be suppressed by TGF-beta 2.