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Biomedical subjects

H Takeda

Publications and source records attributed to H Takeda.

At least 73 records · Page 4Linked to original sources

Combined hepatocellular carcinoma and cholangiocarcinoma growing into the common bile duct.

We report a patient with combined hepatocellular carcinoma and cholangiocarcinoma (HCC-CC) growing into the common bile duct (CBD) and showing obstructive jaundice within 2 years of the onset of the disease. The patient was a 59-year-old Japanese man in whom, at the age of 57 years. a hepatic tumor was discovered by diagnostic imaging during follow-up of hepatitis B surface antigen (HBsAg)-positive liver cirrhosis. The tumor was diagnosed as HCC. Epirubicin was injected twice, intraarterially. The patient then received oral etoposide therapy for the next 14 months. The treatment was initially effective, but approximately 2 years after the hepatic tumor was discovered, local recurrence of the tumor and a tumor thrombus in the CBD were discovered. Although he was treated with percutaneous transhepatic biliary drainage (PTBD), to reduce obstructive jaundice, the jaundice was irreversible and he died of severe hepatic failure. The autopsy findings confirmed that the hepatic tumor was HCC-CC, in which the HCC and CC components expressed alpha-fetoprotein (AFP) and carbohydrate antigen 19-9 (CA19-9), respectively, which accurately reflected the disease process. The underlying mechanism of the growth of HCC-CC into the CBD may differ from the underlying mechanism of the development of icteric-type HCC.

Bile Ducts, Intrahepatic↗

Differences between squamous cell carcinoma and keratoacanthoma in angiotensin type-1 receptor expression.

Angiotensin II receptors are the specific receptors of angiotensin II of the renin-angiotensin system. The existence and role of the receptors in the skin have not been determined. We immunohistochemically studied the expression of angiotensin receptors in the human skin. The results demonstrated the expression of angiotensin type 1 receptor (AT1) in the normal human suprabasal epidermis. The expression pattern suggests the role of AT1 in association with differentiation. In addition, we studied the expression of AT1 in squamous cell carcinoma (SCC) of the skin, SCC of the lip, and keratoacanthoma (KA). Our experiments showed that high, intermediate, and low levels of AT1 were observed in 37 (74.0%), 7 (14.0%), and 2 (4.0%) of 50 cases of SCC of the skin, respectively, and the negative periphery pattern was observed in 17 (77.3%) of 22 cases of KA. These observations suggest that the immunohistochemical study of AT1 is useful to distinguish SCC from KA. Studying the role and distribution of AT1 may help in understanding the pathophysiology of the skin.

Adult↗

Status of PACS and technology assessment in Japan.

The situation of PACS installations in Japan from 1987 to 1999 has been investigated. By 1999, 751 PACS units have been installed. Of these, 613 are small-size PACS with less than four image display terminals, 96 are medium-size with 5-14 terminals and 42 are large-size with 15 up to 300 terminals. The 42 hospitals with large sized PACS have been retrospectively investigated from 1984 for PACS experiments and from 1989 for PACS operation. Most of these 42 hospitals have increased the number of PACS terminals by installing additional PACS units instead of reinforcing the existing single PACS. Some (23%) PACS installations have obviously not been successful because of low image transfer speed and inadequate image quality. The use of DICOMM interfaces has increased the number of modalities connected to PACS and influenced the spread of PACS installations in Japan. The status of HIS and RIS coupling to PACS and the use of PACS in primary diagnosis or in image referral are discussed. Assessment of PACS is now in a very early stage. Baseline studies of HIS/RIS/PACS effectiveness have been carried out to assess quantitatively the PACS merit. Radiologists' answers to the questionnaire on PACS usage do not fully support the finding that the number of PACS installations is growing in Japan.

Humans↗

Pharmacological characterization and visualization of the glial serotonin transporter.

Astrocytes contain transport systems that are capable of removing various neurotransmitters from the synaptic cleft by transporters present in the plasma membrane. Glial serotonin transporter (SERT) plays an important role in the re-uptake of 5-hydroxytryptamine (5-HT). We examined the pharmacological characterization of 5-HT uptake into rat cortical synaptosomes and cultured rat astrocytes, and the immunodetection of glial SERT proteins using specific site-directed monoclonal antibodies (MoAb). Furthermore, using a reverse transcriptase-polymerase chain reaction (RT-PCR) method, we addressed the expression of SERT mRNA in cultured rat astrocytes. We investigated the inhibitory effects of various monoamine uptake inhibitors on the uptake of [3H]5-HT into cultured astrocytes and cortical synaptosomes. Tricyclic antidepressants (clomipramine and imipramine) as well as selective serotonin re-uptake inhibitors (fluvoxamine, fluoxetine and zimelidine) were very potent inhibitors of [3H]5-HT uptake in both preparations. In contrast, the inhibitory effects of NE uptake inhibitors (nisoxetine and desipramine) and cocaine were weaker than those of 5-HT uptake inhibitors. In addition, dopamine (DA) uptake inhibitors (nomifensine and GBR-12935) exhibited a Ki value in the low micromolar range. The inhibitory potencies were in the order 5-HT uptake inhibitors (clomipramine, fluvoxamine, fluoxetine, imipramine and zimelidine) > NE uptake inhibitors (nisoxetine and desipramine) = cocaine > DA uptake inhibitors (nomifensine and GBR-12935). There was no difference in the order of the inhibitory effects of various monoamine uptake inhibitors between the two preparations. A correlation analysis of the potencies of various monoamine uptake inhibitors in the inhibition of [3H]5-HT into cultured astrocytes and cortical synaptosomes produced a highly significant correlation coefficient of 0.9893 (P < 0.0001). Immunocytochemical staining using anti-SERT MoAb in cultured astrocytes revealed that the plasma membrane, as well as intracellular, perinuclear compartments, presumably endoplasmic reticulum or golgi membranes, showed a considerable level of immunoreactivity. Extracts of astrocytes and synaptosomes from the cortex were immunoblotted with anti-SERT MoAb. SDS-PAGE/Western blots indicate that anti-SERT MoAb recognized two bands of 120 and 73 kDa in both preparations. RT-PCR demonstrated that astrocytes in cultured expressed mRNA for the cloned SERT protein, which has been characterized as the neuronal SERT. These pharmacological experiments indicate that this uptake process takes place through glial SERT that is very similar to neuronal SERT. Furthermore, the present data also indicate that the presence of the mRNA and protein for the neuronal SERT were established in cultured rat astrocytes, and the polypeptide portion of SERT in astrocytes and frontal cortex could be the same gene product.

Animals↗

Methyl-4-phenylpyridinium (MPP(+))-evoked dopamine release from rat striatal slices: possible roles of voltage-dependent calcium channels and reverse dopamine transport.

We examined the properties of voltage-dependent Ca(2+) channels (VDCCs) mediating 1-methyl-4-phenylpyridinium (MPP(+))-evoked [3H]DA release from rat striatal slices. In some cases, the Ca(2+)-independent efflux of neurotransmitters is mediated by the high-affinity neurotransmitter-uptake systems. To determine whether such a mechanism might be involved in MPP(+)-evoked [3H]DA release. MPP(+) (1,10 and 100 microM) evoked the release of [3H]DA from rat striatal slices in a concentration-dependent manner. In the absence of Ca(2+), MPP(+) (10 and 100 microM)-evoked [3H]DA release was significantly decreased to approximately 50% of control (a physiological concentration of Ca(2+)). In the presence of Ca(2+), nomifensine (0.1,1 and 10 microM) dose-dependently and significantly inhibited the MPP(+)-evoked release of [3H]DA. Nomifensine (1 and 10 microM) also dose-dependently and significantly inhibited the MPP(+)-evoked release of [3H]DA under Ca(2+)-free conditions. MPP(+)-evoked [3H]DA release was partly inhibited by nicardipine (1 and 10 microM), an L-type Ca(2+) channel blocker. On the other hand, the N-type Ca(2+) channel blocker omega-conotoxin-GVIA (omega-CTx-GVIA) (1 and 3 microM) did not affect this release. omega-agatoxin-IVA (omega-Aga-IVA) at low concentrations (0.1 microM), which are sufficient to block P-type Ca(2+) channels alone, also had no effect. On the other hand, MPP(+)-evoked [3H]DA release was significantly decreased by high concentrations of omega-Aga-IVA (0.3 microM) that would inhibit Q-type Ca(2+) channels. In addition, application of the Q-type Ca(2+) channel blocker omega-conotoxin-MVIIC (omega-CTx-MVIIC) (0.3 and 1 microM) also significantly inhibited MPP(+)-evoked [3H]DA release. These results suggest that MPP(+)-evoked [3H]DA release from rat striatal slices is largely mediated by Q-type Ca(2+) channels, and the Ca(2+)-independent component is mediated by reversal of the DA transport system.

1-Methyl-4-phenylpyridinium↗

Dynamic gadolinium-enhanced MR imaging of pituitary adenomas: usefulness of sequential sagittal and coronal plane images.

Dynamic magnetic resonance (MR) imaging for pituitary adenomas is usually performed in a coronal direction; however, small lesions between slices, or lesions located at the anterior or posterior aspect of the pituitary gland might be overlooked on MR images in only the coronal direction. The purpose of our study was to evaluate whether consecutive dynamic MR images in the coronal and sagittal planes improve detection of pituitary adenomas. Eighteen patients with pituitary microadenomas and nine with healthy pituitary glands were included in this study. MR images were performed with 1.5 T superconductive units and commercially-available head coils. After a 5 ml gadolinium contrast injection, eight serial dynamic sagittal images were obtained. Within 3 or 6 min, this was followed by a 10-15 ml gadolinium injection and acquisition of eight serial dynamic coronal images. Dynamic MR images and conventional noncontrast- and contrast-enhanced sagittal and coronal T1-weighted images were evaluated independently in a blind fashion by two neuroradiologists regarding the depiction of pituitary microadenomas. The sensitivities of dynamic enhanced MR imaging in the detection of microadenomas were 61.1% in sagittal direction, 72.2% in coronal direction respectively, and were superior to those of conventional noncontrast- and contrast-enhanced T1-weighted imaging (22.2-50%). The sensitivity of a combination of sagittal and coronal dynamic enhanced MR imaging for the detection of microadenomas was 88.9% and was superior to those of conventional noncontrast- and contrast-enhanced T1-weighted imaging combining sagittal and coronal directions (61.1%, 61.1%) (P<0.05, P<0.05, respectively). The specificity and accuracy of dynamic enhanced MR imaging with combination of sagittal and coronal images was 88.9% respectively. Dynamic gadolinium-enhanced MR imaging, especially using both sagittal and coronal planes, was concluded to be useful for the detection of pituitary microadenomas.

Adenoma↗

Renin angiotensin system-dependent hypertrophy as a contributor to heart failure in hypertensive rats: different characteristics from renin angiotensin system-independent hypertrophy.

OBJECTIVES: This study aimed to characterize the difference between renin angiotensin system (RAS)-dependent and RAS-independent hypertrophy and their differential contribution to the transition to heart failure. BACKGROUND: Hypertensive left ventricular (LV) hypertrophy develops with RAS activation in the heart; however, LV hypertrophy develops even without RAS activation. METHODS: Left ventricular geometry and function were assessed in Dahl salt-sensitive rats placed on an 8% NaCl diet from seven weeks old (hypertensive rats) and in those placed on an 0.3% NaCl diet (control rats, n = 8). The hypertensive rats were randomized to no treatment (n = 8) or treatment with the angiotensin type 1 receptor (AT1R) antagonist candesartan (1 mg/kg per day, n = 10) after the baseline echocardiography study. RESULTS: From 7 to 13 weeks, AT1R blockade at a subdepressor dose did not restrain the development of LV hypertrophy but prevented narrowing of LV diastolic dimension, leading to the normalization of abnormally decreased end-systolic wall stress in the untreated rats. Progressive development of LV hypertrophy in spite of lower than normal end-systolic wall stress (excessive hypertrophy) after 13 weeks was suppressed by the AT1R blockade. Elevation of LV end-diastolic pressure and prolongation of Tau were associated with histological evidence of myocyte hypertrophy and massive interstitial fibrosis in the untreated rats, and none of these was evident in the treated rats. CONCLUSIONS: Renin-angiotensin system activation and AT1R signaling may be dispensable for the development of early adaptive LV hypertrophy and closely linked to the transition to heart failure.

Animals↗

Expression of zebrafish btg-b, an anti-proliferative cofactor, during early embryogenesis.

BTG/tob family proteins are thought to be a potential tumor suppressor due to their anti-proliferative activity. We cloned zebrafish btg-b, a member of the BTG1/2 subfamily, using in situ hybridization screening. The tissue-specific expression of btg-b is first observed in the organizer region at the early gastrula stage. Later in development, the forebrain, the hindbrain, the polster and the paraxial mesoderm transiently express btg-b. Recently, mouse Btg1 and Btg2 have been shown to be a cofactor for Hoxb9. Double in situ hybridization with zebrafish btg-b and hoxb9a indicates that the expression domains of these two genes overlap in the posterior paraxial mesoderm.

Amino Acid Sequence↗

A novel sox gene, 226D7, acts downstream of Nodal signaling to specify endoderm precursors in zebrafish.

Vertebrate endoderm development has recently become the focus of intense investigation. We have identified a novel sox gene, 226D7, which is important in zebrafish endoderm development. 226D7 was isolated by an in situ hybridization screening for genes expressed in the yolk syncytial layer (YSL) at the blastula stage. 226D7 is expressed mainly in the YSL at this stage and, during gastrulation, its expression is also detected in the forerunner cells and endodermal precursor cells. The expression of 226D7 is positively regulated by Nodal signaling. The knockdown of 226D7 using morpholino antisense oligonucleotides results in a lack of sox17-expressing endodermal precursor cells during gastrulation, and, consequently, lacks endodermal derivatives such as gut tissue. The effect is strictly restricted to the endodermal lineage, while the mesoderm is normally formed, a phenotype that is nearly identical to that of the casanova mutant (Dev. Biol. 215 (1999) 343). We further demonstrate that overexpression of 226D7 increases the number of sox17-expressing endodermal progenitor cells without upregulating the expression of the Nodal genes, cyclops and squint. Region-specific knockdown and overexpression of 226D7 by injection into the YSL suggest that 226D7 in the YSL is not involved in endoderm formation and 226D7 in the endoderm progenitor cells is important for endoderm development. Taken together, our data demonstrate that 226D7 is a downstream target of Nodal signal and a critical transcriptional regulator of early endoderm formation.

Amino Acid Sequence↗

Transcriptional regulation of Mesp1 and Mesp2 genes: differential usage of enhancers during development.

Mesp1 and Mesp2 encode bHLH-type transcription factors, Mesp1 and Mesp2, respectively. The expression of both genes is observed in the nascent mesoderm, and subsequently in the rostral presomitic mesoderm. To determine the regulatory mechanism for gene expression, we attempted to identify enhancer elements by transient transgenic analysis. At least two enhancers, which are responsible for the expression of the two genes in the early mesoderm (early mesodermal enhancer, EME) and the presomitic mesoderm (PSM enhancer, PSME), and one suppressor, which is responsible for the rostrally restricted expression in the presomitic mesoderm, were identified. Deletion studies of these enhancer elements indicate that either gene may use the same enhancer for early mesoderm development, whereas both genes may utilize separate enhancers to regulate their expression in the presomitic mesoderm.

Animals↗

Waveform of sympathetic skin response in diabetic patients.

OBJECTIVE: The aim of this study was to investigate whether there were differences in amplitude and latency among the different waveform patterns of sympathetic skin response (SSR) in diabetic patients. The authors also investigated whether the proportion of the SSR waveform patterns was influenced by diabetic polyneuropathy (DP), symptoms of dysautonomia, and impaired R-R interval variation of the heart rate. DESIGN/METHODS: Twenty SSRs from palm skin were analyzed in 53 diabetic patients and 45 normal subjects. Waveforms were classified as either the P type, in which the positive component was larger than the negative one, or the N type, in which the negative component was larger than the positive one. The patterns of occurrence in these two waveform types were classified into 3 kinds, i.e. P, N, and M patterns. In the P and N patterns, all the SSRs were of the P and N types, respectively. The M pattern had both P and N types during consecutive recordings. RESULTS: The patients' age and glycosylated hemoglobin values did not differ among the 3 SSR patterns. The P pattern, however, had a larger amplitude and shorter latency than the N pattern, just as previously reported in a normal population. The distribution of the SSR patterns in diabetic patients was not statistically different from that in the normal controls, and it was not influenced by the DP, symptoms of dysautonomia, or impaired R-R interval variation of the heart rate. CONCLUSIONS: The distribution of the SSR waveform patterns was not influenced by the pathological conditions related to diabetes. It might be advised to confirm the balanced distribution of the SSR waveform patterns in patient and control groups before comparing the values of amplitude and latency between the two groups.

Adolescent↗

Attributable risk of H. pylori in peptic ulcer disease: does declining prevalence of infection in general population explain increasing frequency of non-H. pylori ulcers?

Recent reports in the United States have found that fewer peptic ulcers are due to Helicobacter pylori than previously believed. The aim of this study is to determine if the declining prevalence of H. pylori infection in the general population can account for the apparent increase in the frequency of non-H. pylori ulcers. A total of 396 patients with peptic ulcer or ulcer scar were enrolled in this study. The pre-1950 population consisted of 149 patients with gastric ulcers and with 44 duodenal ulcers. The post-1950 population consisted of 96 patients with gastric ulcers and 107 with duodenal ulcers. The frequency of H. pylori-negative gastric ulcers was 5.4% in patients born before 1950 and 4.2% in patients born after 1950, and the frequency of H. pylori-negative duodenal ulcers was 0% and 1.9%, respectively. There are no statistical differences between the two populations in gastric and duodenal ulcers. H. pylori seropositivity was 74.9% in asymptomatic volunteers born before 1950 and 20.7% in those born after 1950 (P < 0.01) in the general population. The attributable risk of H. pylori infection in peptic ulcer diseases was not affected by the prevalence of H. pylori infection in the general population in Japan. This suggests that the apparent increase in frequency of non-H. pylori ulcers in the United States is not simply due to the declining prevalence of infection. Other explanations for non-H. pylori ulcers should be sought.

Adult↗

Effects of sustained low-flow ischemia and reperfusion on Ca2+ transients and contractility in perfused rat hearts.

We investigated changes in cytoplasmic Ca2+ concentration ([Ca2+]i) and in left ventricular contractility during sustained ischemia and reperfusion in isolated beating rat hearts. Hearts from male Sprague-Dawley rats were perfused retrogradely and were loaded with 4 microM fura-2. Low-flow global ischemia was induced by reducing perfusion flow to 10% and by electric pacing. The hearts were exposed to ischemia for 10 min or 30 min and then reperfused. [Ca2+]i was measured by monitoring the ratio of 500 nm fluorescence excited at 340 and 380 nm while simultaneously measuring left ventricular pressure (LVP). To determine diastolic [Ca2+]i, background autofluorescence was subtracted. LVP rapidly decreased from 82.3+/-8.2 to 17.1+/-2.9 mmHg , whereas the amplitude of the Ca2+ transient did not change significantly during the first 1 min of ischemia. After 10 min of ischemia, the amplitude decreased to 60.8+/-10.6% (p < 0.05) and diastolic [Ca2+]i increased by 26.3+/-2.9% (p < 0.001) compared with the pre-ischemic value (n = 8). When the hearts were reperfused after 10 min of ischemia, the amplitude of the Ca2+ transient and LVP recovered to 79.0+/-7.2% and 73.2+/-7.5 mmHg, respectively. Whereas diastolic [Ca2+]i decreased to the preischemic value. In the hearts exposed to 30 min of ischemia (n = 10), diastolic [Ca2+]i increased even further by 32.7+/-5.3% at the end of ischemia and continued increasing during the 10 min of reperfusion by 42.6+/-15.6%. Six of 10 hearts developed ventricular fibrillation (VF) and intracellular Ca2+ overload after reperfusion. Recovery of LVP after reperfusion was significantly smaller in the hearts exposed to 30 min of ischemia than in the hearts exposed to 10 min of ischemia (58.9+/-11.7 vs. 97.2+/-3.0% of pre-ischemic value, p < 0.05). Diastolic [Ca2+]i also increased under hypoxic conditions (N2 bubbling) in this model. These results suggest that increases in diastolic [Ca2+]i might play an important role in myocardial contractile dysfunction and viability in ischemia-reperfusion injury.

Animals↗

The making of the somite: molecular events in vertebrate segmentation.

The reiterated structures of the vertebrate axial skeleton, spinal nervous system and body muscle are based on the metameric structure of somites, which are formed in a dynamic morphogenetic process. Somite segmentation requires the activity of a biochemical oscillator known as the somite-segmentation clock. Although the molecular identity of the clock remains unknown, genetic and experimental evidence has accumulated that indicates how the periodicity of somite formation is generated, how the positions of segment borders are determined, and how the rostrocaudal polarity within somite primordia is generated.

Animals↗

Protective effects of 5-HT1A receptor agonists against emotional changes produced by stress stimuli are related to their neuroendocrine effects.

1. The effects of the 11beta-hydroxylase inhibitor metyrapone on the protective effects of serotonin (5-hydroxytryptamine; 5-HT)(1A) receptor agonists against emotional changes produced by acute restraint stress were examined in mice. 2. Changes in the emotional state of mice were evaluated in terms of changes in exploratory activity, i.e. total locomotor activity, number and duration of rearing and head-dipping behaviours, and latency to the first head-dipping, using an automatic hole-board apparatus. 3. Treatment with the 5-HT(1A) receptor agonists flesinoxan (1 mg kg(-1), i.p.) and R(+)-2-di-n-propylamino-8-hydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide (8-OH-DPAT; 1 mg kg(-1), i.p.) 24 h prior to exposure to stress significantly suppressed the decrease in various exploratory behaviours that was observed immediately after the exposure to acute restraint stress (60 min). The effects of flesinoxan (1 mg kg(-1), i.p.) and 8-OH-DPAT (1 mg kg(-1), i.p.) were antagonized by co-injection with N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexanecarboxamide trihydrochloride (WAY100635; 1 mg kg(-1), i.p.), a selective 5-HT(1A) receptor antagonist. 4. Flesinoxan (1 mg kg(-1), i.p.) and 8-OH-DPAT (1 mg kg(-1) i.p.) significantly increased the plasma corticosterone level, and these effects of 5-HT(1A) receptor agonists were dose-dependently blocked by pretreatment with metyrapone (12.5 and 25 mg kg(-1), s.c.). 5. Metyrapone (25 mg kg(-1), s.c.) alone did not modify the stress-induced changes in exploratory behaviours. Pretreatment with metyrapone (12.5 and 25 mg kg(-1), s.c.) partly antagonized the protective effects of flesinoxan (1 mg kg(-1), i.p.) and 8-OH-DPAT (1 mg kg(-1), i.p.) with regard to only the number and duration of head-dipping behaviours. 6. These results suggest that activation of the adrenocortical system via 5-HT(1A) receptors may facilitate some adaptive mechanism(s) involved in the recognition of and/or ability to cope with stressful situations.

Animals↗

Efficacy of triple therapy with rabeprazole for Helicobacter pylori infection and CYP2C19 genetic polymorphism.

BACKGROUND: Rabeprazole is a new, potent, proton pump inhibitor. The metabolism of rabeprazole is less dependent on CYP2C19 genetic polymorphism. METHODS: A total of 102 Helicobacter pylori-positive patients with gastric ulcer were randomly allocated to three groups: rabeprazole 10 mg (RAC10), rabeprazole 20 mg (RAC20) or rabeprazole 40 mg (RAC40) plus amoxicillin 750 mg and clarithromycin 200 mg twice daily for 7 days. CYP2C19 genotype was determined by the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: All-patients-treated-based eradication rates in patients treated with RAC10, RAC20 and RAC40 were 83%, 77% and 90%, respectively, and per protocol-based eradication rates were 83%, 80% and 90%, respectively. The eradication rates in the three groups were not significantly different. There was also no significant difference between the all-patients-treated-based eradication rate in CYP2C19 extensive metabolizers and that in poor metabolizers (86% vs. 77%). Adverse events were 12% in extensive metabolizers and 23% in poor metabolizers, and the difference in these incidence rates was also not statistically significant. CONCLUSIONS: Triple therapy with 10 mg of rabeprazole combined with amoxicillin/clarithromycin is effective for Japanese patients with H. pylori infection, and the H. pylori eradication rate is not affected by CYP2C19 genetic polymorphism.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Immunohistochemical study of angiotensin receptors in normal human sweat glands and eccrine poroma.

BACKGROUND: Angiotensin II exerts its actions through its specific receptors. However, expression of these receptors has not been determined in sweat glands. OBJECTIVES: To clarify the expression and localization of the angiotensin receptors in normal human sweat glands and eccrine poroma. METHODS: Expression of angiotensin type 1 (AT1) and type 2 (AT2) receptors in normal human eccrine and apocrine sweat glands and 12 cases of eccrine poroma was studied using immunohistochemistry. RESULTS: In eccrine sweat glands, the acrosyringium and the inner surfaces and luminal cells of the intradermal duct showed positive staining with AT1. In apocrine sweat glands, the intraepithelial duct and luminal cells of the intradermal duct showed positive staining with AT1. In 12 cases of eccrine poroma, some of the tumour cells in the tumour strands and cells surrounding the luminal structures stained positively. There were no positive findings with AT2. CONCLUSIONS: Studying AT1 distribution may be useful in understanding the pathophysiology of sweat glands and sweat gland tumours.

Acrospiroma↗

Effect of vibration on auditory organ systems in low-birth weight infants treated with high-frequency oscillatory ventilation: 5 year outcome.

BACKGROUND: To determine the effects of vibration exposure caused by high-frequency oscillatory ventilation (HFOV) on the auditory organ systems in low-birth weight (LBW) infants. METHODS: Between 1989 and 1990, 30 LBW infants who received assisted ventilation with HFOV (n = 14) or conventional mechanical ventilation (CMV; n = 16) in the level III neonatal intensive care unit at Tokyo Metropolitan Ohtsuka Hospital were enrolled in this study. The effects of vibration exposure on the auditory system structures were investigated with auditory brainstem responses (ABR) at 37-41 weeks of postconceptional age and at 6, 12, 18 and 24 months of age until they passed and follow-up studies were performed at least until 5 years of age. RESULTS: All infants enrolled in the study survived at discharge and one (7.1%) infant in the HFOV group and two (12.5%) in the CMV group failed the initial ABR test, but there were no significant differences between the two groups. Auditory brainstem response abnormalities were still observed in one infant in the HFOV group at 6 months of age, but this child died at 9 months of age because of meningitis. In contrast, in the CMV group, one patient passed the ABR test at 6 months of age, but another remained abnormal at 5 years of age. One of three infants with ABR abnormalities at 6 months of age had neurologic sequelae at 5 years of age and one of 28 infants who passed the initial ABR test was detected with cerebral palsy. No patients with hearing loss were clinically detected at 5 years of age. CONCLUSIONS: The results of the serial ABR examinations and the 5 year follow-up studies suggest that vibration exposure caused by HFOV may not increase the adverse effects on the auditory system in LBW infants.

Audiometry, Evoked Response↗