A study of vertebrobasilar artery dissection with subarachnoid hemorrhage

We retrospectively studied clinical characteristics of 368 patients with cerebral artery dissections who were diagnosed in 172 Japanese hospitals. Of these patients, 130 (35%) presented with subarachnoid hemorrhage, 217 (59%) with cerebral infarctions, and 21 (6%) with transient ischemic attacks. We analyzed 109 (84%) subarachnoid hemorrhage cases caused by vertebrobasilar artery dissection to evaluate conservative and surgical treatment from the viewpoint of postoperative rerupture and infarction.Subsequent ruptures were observed in 14% of the 21 cases with nonsurgical treatment. For the preventive purpose of rerupture, 88 patients received surgical interventions: 68 trappings, 13 proximal occlusions, 6 aneurysmal sac occlusions and 1 stenting. Rerupture was experienced in 33% of the aneurysmal sac occlusion patients while not occurring in the other three surgical interventions. In the group without vascular anastomosis, postoperative cerebral infarction was observed in 25% of the trapping, none of the proximal occlusion and 33% of the aneurysmal sac occlusion cases.In this study, aneurysmal sac occlusion treatments were more frequently complicated by rerupture or cerebral infarction postoperatively than the other treatment methods. It was difficult to determine which surgical treatment can achieve better surgical outcome among the proximal occlusion and trapping with or without vascular anastomosis.

[Pulmonary pleomorphic carcinoma; an investigation of thirteen cases]

Pleomorphic carcinoma is a rare pulmonary epithelial malignant tumor defined in the World Health Organization classification updated in 1999. We investigated the clinical findings and prognosis associated with this tumor since to our knowledge they have yet to be well-understood. Between 2000 and 2006, in our hospital 387 patients underwent surgical resection for primary nonsmall cell lung carcinoma (NSCLC). Of these, 13 (3.4%) were diagnosed as pleomorphic carcinoma. We compared the clinical and pathological data between the patients with pleomorphic carcinoma (n = 13) and patients with other NSCLC (n = 374). Twelve (92.3%) of our patients were men and 9 (69.2%) were symptomatic. These tumors were located predominantly in an upper lobe and were associated more often with adjacent bullae than were other NSCLC. Surgical resection in 4 of the cases was incomplete due to tumor invasion into mediastinum, aortic arch, pleurae and/or chest wall. None of the diagnoses could be confirmed preoperatively. Thus, invasion of surrounding tissue occurred frequently and early. Although there are no defined management strategies for pleomorphic carcinoma, it is important to make the diagnosis early and perform complete resection if possible.

Comparison of pre- vs. postmeal administration of miglitol for 3 months in type 2 diabetic patients

AIM

alpha-Glucosidase inhibitors (alphaGIs) primarily modify postprandial plasma glucose levels and should be taken just before meals. We previously demonstrated that a single administration of miglitol within 30 min after the start of a meal was equally effective as when administered just before a meal. We here compared pre- vs. postmeal administration of miglitol for 3 months in type 2 diabetic patients.

METHODS

Thirty-one type 2 diabetic outpatients who had never been treated with insulin injections or alphaGIs were randomized to two groups: patients in group A were asked to take miglitol just before meals, while patients in group B were asked to take miglitol after meals. We measured 1,5-anhydroglucitol (1,5-AG) and HbA(1C) levels in these patients.

RESULTS

The administration of miglitol after meals for a 3-month period decreased HbA(1C) and increased 1,5-AG levels to the same extent as when administered just before meals. The incidence of adverse effects seemed to be unrelated to the timing of the miglitol administration.

CONCLUSIONS

Our results suggest that if patients have difficulty remembering to take miglitol just before meal, they should be instructed to take the medicine together with other medicine(s) after the meal; this instruction may improve the treatment compliance of diabetic patients.

OLGA staging for gastritis: a tutorial

Atrophic gastritis (resulting mainly from long-standing Helicobacter pylori infection) is a major risk factor for (intestinal-type) gastric cancer development and the extent/topography of the atrophic changes significantly correlates with the degree of cancer risk. The current format for histology reporting in cases of gastritis fails to establish an immediate link between gastritis phenotype and risk of malignancy. The histology report consequently does not give clinical practitioners and gastroenterologists an explicit message of use in orienting an individual patient's clinical management. Building on current knowledge of the biology of gastritis and incorporating experience gained worldwide by applying the Sydney System for more than 15 years, an international group of pathologists (Operative Link for Gastritis Assessment) has proposed a system for reporting gastritis in terms of stage (the OLGA staging system). Gastritis staging arranges the histological phenotypes of gastritis along a scale of progressively increasing gastric cancer risk, from the lowest (stage 0) to the highest (stage IV). This tutorial aims to provide unequivocal information on how to consistently apply the OLGA staging system in routine diagnostic histology practice.

A cytogenetic survey of 449 patients in a Japanese institution for the mentally retarded

A cytogenetic survey was carried out on 449 patients (261 males and 188 females) in an institution for the mentally retarded in Japan. A total of 37 patients (8.1%) were shown to have chromosome abnormalities. There were 33 individuals (7.3%) with 21 trisomy. In addition, we found one patient with 46,XY/47,XY,+12p, one with 46,XY,r(22), and one with 45,XY,-13,-14,+t(13q14q). Only one female was found to have an abnormal sex chromosome constitution, 47,XXX. The significant contribution of chromosome abnormalities in the etiology of mental retardation is also shown in the present survey. The most common chromosome abnormality was 21 trisomy, as seen in other similar surveys.

Severe mandibuloacral dysplasia caused by novel compound heterozygous ZMPSTE24 mutations in two Japanese siblings

Mandibuloacral dysplasia (MAD) is a rare autosomal recessive progeroid syndrome, characterized by mandibular hypoplasia, acroosteolysis affecting distal phalanges and clavicles, delayed closure of the cranial sutures, atrophic skin, and lipodystrophy. Recently, mutations in lamin A/C (LMNA) and zinc metalloprotease (ZMPSTE24), involved in post-translational processing of prelamin A to mature lamin A, have been identified in MAD kindreds. We now report novel compound heterozygous mutations in exon 1 (c.121C>T; p.Q41X) and exon 6 (c.743C>T; p.P248L) in ZMPSTE24 in two Japanese sisters, 7- and 3-year old, with severe MAD and characteristic facies and atrophic skin. The older sister had lipodystrophy affecting the chest and thighs but sparing abdomen. Their parents and a brother, who were healthy, had heterozygous mutations. The missense mutation, P248L, was not found in 100 normal subjects of Japanese origin. The mutant Q41X was inactive in a yeast halo assay; however, the mutant P248L retained near normal ZMPSTE24 activity. Immunoblots demonstrated accumulation of prelamin A in the patients' cell lysates from lymphoblasts. The lymphoblasts from the patients also revealed less intense staining for lamin A/C on immunofluorescence. We conclude that ZMPSTE24 deficiency results in accumulation of farnesylated prelamin A, which may be responsible for cellular toxicity and the MAD phenotype.

A shear-induced in vitro platelet function test can assess clinically relevant anti-thrombotic effects

Morphological features of haemostatic plugs formed in vitro under high shear forces were investigated. Electron microscopy confirmed the relevance of such haemostatic plug to a platelet-rich arterial thrombus, which is formed in vivo . In rat blood samples, the effects of anticoagulants and various antiplatelet agents on platelet reactivity (rate of haemostatic plug formation) and subsequent coagulation of the flowing blood were investigated. Haemostasis did not occur in citrated blood, and heparin greatly inhibited the shear-induced platelet reaction. Aspirin (1 mM), a thromboxane A(2) receptor antagonist (5 microM), a stable prostacyclin (0.55 nM), a stable prostaglandin E(1) (141 nM) and a phosphodiesterase inhibitor (100 microM) were tested. All these agents exerted significant inhibitory effect on shear-induced platelet reaction, including the inhibition of the very first phase of platelet plug formation, due to aggregation of shear-activated platelets. Except for the phosphodiesterase inhibitor, which prolonged clotting time, none of the above agents affected dynamic coagulation. These results suggest that the employed in vitro shear-induced thrombosis/haemostasis test can reveal in vivo the antithrombotic effect of various agents independently of their mechanism of action.

Mental health service requirements in a Japanese medical centre emergency department

BACKGROUND

A significant number of emergency department (ED) patients in Japan may be affected by mental health problems leading to attempted suicide. This retrospective descriptive study aimed to explore mental health service needs in a Japanese medical centre ED.

METHODS

Data on all inpatients were collected within 24 h of admission to the ED of a medical centre in Tokyo from 1st February 2004 to the 31st of January 2005.

RESULTS

A total of 14.4% (95% CI 13.0 to 16.0) of ED visits required psychiatric services and 23.4% (95% CI 21.7 to 25.3) of inpatients had experienced psychologically traumatic events.

CONCLUSIONS

Approximately 38% (95% CI 35.8 to 39.9) of patients presenting to an ED could be affected by mental health problems.

Maternal smoking during pregnancy and genetic polymorphisms in the Ah receptor, CYP1A1 and GSTM1 affect infant birth size in Japanese subjects

Genetic susceptibility to tobacco smoke might have relation to adverse pregnancy outcomes. To estimate the effects of maternal smoking and genetic polymorphisms on infant birth weight and length, we conducted a prospective cohort study of 293 women who delivered singleton live births in Sapporo, Japan. Birth weight and length were significantly lower among infants born to continuously smoking women having the aryl hydrocarbon receptor (AhR) wild type genotype (Arg/Arg; 211 g +/- 76 g; 1.2 cm +/- 0.4 cm, p < 0.01 and p < 0.01, respectively), the CYP1A1 variant genotype (m1/m2 + m2/m2; 170 g +/- 64 g, 0.8 cm +/- 0.3 cm, p < 0.01 and p < 0.05, respectively), or the GSTM1 null genotype (171 g +/- 58 g, 0.6 cm +/- 0.3 cm, p < 0.01 and p < 0.05, respectively). When combinations of these genotypes were considered, birth weight and length were significantly lower for infants of continuously smoking women in the AhR wild type + CYP1A1 variant group (315 g +/- 116 g; 1.7 cm +/- 0.6 cm, p < 0.01 and p < 0.01, respectively) and in the CYP1A1 variant + GSTM1 null group (237 g +/- 92 g; 1.3 cm +/- 0.5 cm, p < 0.05 and p < 0.01, respectively). These genotypes did not confer adverse effects among women who had never smoked; therefore, maternal smoking in combination with maternal AhR, CYP1A1 and GSTM1 genetic polymorphisms may adversely affect infant birth size.

ATX-S10(Na)-photodynamic therapy is less carcinogenic for mouse skin compared with ultraviolet B irradiation

BACKGROUND

Photodynamic therapy (PDT) is available for the treatment of various skin tumours and other skin diseases. Ultraviolet (UV) irradiation induces DNA damage, cyclobutane pyrimidine dimers (CPD) (6-4) photoproducts (6-4PP) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), all of which are carcinogenic for the skin. However, effects of PDT on DNA damage and carcinogenesis are unclear.

OBJECTIVES

To compare the production of photoproducts and the induction of skin tumours in mouse epidermis treated with UVB or PDT.

METHODS

We performed UVB irradiation or ATX-S10(Na)-PDT on the skin of 20 hairless mice, in each case, and analysed DNA damage and tumour induction.

RESULTS

After a single irradiation of UVB on mouse skin, CPD, 6-4PP and 8-OHdG were detected in the nuclei of keratinocytes. In contrast, PDT-treated mouse keratinocytes showed induction of 8-OHdG, but not of CPD or 6-4PP. Skin tumours induced by UVB irradiation (3 kJ m(-2) three times weekly) were observed following 15 weeks of irradiation (mean +/- SEM tumour incidence 3.2 +/- 1.8%; tumour number 3.2 +/- 1.6 per mouse) and increased depending on irradiation times and doses. Following 30 weeks of UVB irradiation (3 kJ m(-2) three times weekly), mean +/- SEM tumour incidence and tumour number were 28.7 +/- 4.8% and 14.2 +/- 2.8% per mouse, respectively. Although skin tumours were also detected in PDT-treated mouse skin following 80 weeks of treatment (mean +/- SEM tumour incidence 9.1 +/- 1.8%; tumour number 12.2 +/- 2.3 per mouse), the number of tumours was not statistically different from untreated mouse skin (mean +/- SEM tumour incidence 4.1 +/- 3.8%; tumour number 5.2 +/- 3.3 per mouse).

CONCLUSIONS

PDT induced 8-OHDG but not CPD or 6-4PP, and was shown to be a relatively safe modality following multiple applications to mouse skin.

[Pulmonary metastasis from colorectal cancer with hepatic metastasis]

We have investigated cases where pulmonary metastasis from colorectal cancer was resected during the last 15 years, comparing a group with liver metastasis [LM (+)] to a group without liver metastasis [LM (-)]. The following are the characteristics of the LM (+) versus LM (-) groups. Gender: male 6, female 5 versus male 9, female 11, age: 61.4+/-11.4 versus 63.9+/-9.4 years, number of lung metastasis: 1.42 versus 1.29, duration of primary-lung metastasis: 1.59+/-1.02 versus 2.55+/-1.46 years, preoperative CEA: 69.3+/-71.1 versus 8.64+/-5.63 ng/ml, ratio of bilateral lung metastasis: 23.0 versus 4.8%, more than 1 ratio of pulmonary metastasis: 38 versus 19%, complete resection ratio of pulmonary metastasis: 84.6 versus 100%, ratio of thoracoscopic surgery: 69.2 versus 66.7%, and 2-year survival ratio: 63 versus 78%. There were no statistically significant differences in these values between the LM (+) and LM (-) group. A larger number of cases and follow-up duration will be required in the future; we think that the resection of pulmonary metastasis from colorectal cancer with liver metastasis can be supported for the present.

Comparison of nonmetal and metal hydrophilic photosensitizer, ATX-S10 (Na) and ATN-2, binding with human serum proteins using spectrophotometry

Intermolecular interactions of human serum proteins with a hydrophilic nonmetalloporphyrin, 13,17-bis(1-carboxypropionyl)carbomoylethyl-8-ethenyl-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetramethylporphyrin sodium salt (ATX-S10 (Na)), or a hydrophilic gallium-metalloporphyrin, diethylenetriamine pentaacetic acid ester of 2-[1-(2-hydroxy-ethoxy)ethyl]-4-vinyl-deuteroporphyrin (IX) Ga complex (ATN-2), were investigated using spectrophotometry. ATX-S10 (Na) caused a bathochromic shift with albumin, high-density lipoprotein and low-density lipoprotein, but little or no shift was observed with hemopexin, transferrin and immunoglobulin G. In contrast, ATN-2 displayed a bathochromic shift only with hemopexin. These results suggest that the association energy of ATX-S10 (Na) with albumin might be slightly greater than that with lipoproteins and that of ATN-2 with hemopexin might be greater than that with other serum proteins.

Orexin (hypocretin) effects on constitutively active inward rectifier K+ channels in cultured nucleus basalis neurons

Orexins are excitatory transmitters implicated in sleep disorders. Because orexins were discovered only recently, their ionic and signal transduction mechanisms have not been well clarified. We recently reported that orexin A (OXA) inhibits G protein-coupled inward rectifier K+ (GIRK) channels in cultured locus coeruleus and nucleus tuberomammillaris neurons. Other work in our laboratory revealed the existence of a novel inward rectifier K+ channel (KirNB), which is located in cholinergic neurons of the nucleus basalis (NB) and possesses unique single-channel characteristics. The mean open time is considerably shorter in KirNB than in Kir2.0 channels. Constitutive activity and a smaller unitary conductance set KirNB apart from cloned Kir3.0 channels. Previously, we found that substance P excites NB neurons by inhibiting KirNB channels. Here we show that orexins suppress KirNB channel activity, likely leading to neuronal excitation. Electrophysiological studies were performed on cultured NB neurons from the basal forebrain. OXA application decreased whole cell conductance through a pertussis toxin (PTX)-insensitive G protein. The OXA-suppressed current was inwardly rectifying with a reversal potential around E(K). Single-channel recordings of NB neurons revealed that constitutively active KirNB channels were transiently inhibited by OXA. Okadaic acid pretreatment abolished the recovery. The results suggest that OXA inhibition of KirNB is mediated by a PTX-insensitive G protein (i.e., G(q/11)), which eventually results in channel phosphorylation. Recovery from this inhibition is by dephosphorylation. These results, taken together with our previous study, suggest that orexin receptors can elicit neuronal excitation through at least two families of inward rectifier K+ channels: GIRK and KirNB channels.

Histological aspects and role of mast cells in Helicobacter pylori-infected gastritis

BACKGROUND

Mast cells are one of the main pro-inflammatory cells, while their knowledge in Helicobacter pylori infection has not been summarized.

METHODS

We reviewed studies on mast cells in H. pylori infection, and summarized the histological aspects and roles.

RESULTS

The density of mast cells is greater in H. pylori-infected than in non-infected subjects. Increased mast cell density in infected gastritis significantly decreases after eradication. On electron microscopy, mast cells in infected gastric mucosa show degranulation. Some experimental studies demonstrate that mast cells are degranulated with H. pylori-derived products.

CONCLUSIONS

Mast cells are actively involved in the pathogenesis of H. pylori-infected gastritis. The possible roles are to initiate and promote the formation of oedema through degranulated and secreted mediators, and to release multiple chemotactic factors, which induce inflammatory cells to infiltrate to the site of oedema, showing acute inflammatory changes. Mast cells also stimulate the degradation of pericellular matrices and the growth of cells in their vicinity, and thereby promote tissue turnover. In chronic H. pylori infection, these reactions continue until the bacteria are eradicated. Mast cells may act both to maintain gastritis and to repair tissue damage in H. pylori-infected chronic gastritis.

Oesophageal adenocarcinoma or gastric cancer with or without eradication of Helicobacter pylori infection in chronic atrophic gastritis patients: a hypothetical opinion from a systematic review

BACKGROUND

As chronic atrophic gastritis is a precancerous condition for gastric cancer and the eradication of Helicobacter pylori infection halts chronic gastritis, eradication of infection may prevent gastric cancer. However, as chronic atrophic gastritis is a risk factor for reflux oesophagitis after eradication of infection, the risk of oesophageal adenocarcinoma may also increase.

METHODS

We systematically reviewed papers and estimated the expected annual incidence of oesophageal or gastric cancer with and without eradication of H. pylori infection in patients with chronic atrophic gastritis.

RESULTS

The expected annual incidence of gastric cancer in patients with corpus atrophy with persistent infection was at least 5.8-fold higher than that for oesophageal adenocarcinoma after the eradication of infection at all ages. Even for patients with accompanying reflux oesophagitis or Barrett's oesophagus, the expected incidence of either gastric or oesophageal adenocarcinoma with persistent infection was higher than that of oesophageal adenocarcinoma after eradication of infection.

CONCLUSION

If eradication of infection lowers the incidence of gastric cancer, it should be recommended for patients with corpus atrophy at all ages irrespective of the presence of reflux oesophagitis or Barrett's oesophagus, especially in populations having a high prevalence of gastric cancer.

Amino-acid change on the antigenic region B1 of H3 haemagglutinin may be a trigger for the emergence of drift strain of influenza A virus

Sera from 27 children and eight older persons, which had been collected in 1998 and 1999 and showed haemagglutination-inhibition (HI) activity against influenza A/Sydney/5/97 (H3N2) strain, were characterized with a binding assay using chimeric haemagglutinin (HA) proteins between A/Aichi/2/68 (A/AI/68) and A/Sydney/5/97 (A/SD/97) strains. Sera from the young children had a tendency to recognize only the antigenic site B1 of the HA1 region. On the other hand, sera of the older individuals were fully reactive to all antigenic sites of HA1 except antigenic site D. Recent epidemic strains, A/Panama/2007/99 (A/PM/99)-like viruses have differences in amino acids in antigenic sites A, C, and B2 but not B1. However, human antisera obtained even from young children had HI activity to Panama-like viruses. The limited epidemic of A/PM/99-like viruses may have been due to the existence of antibody against B1, which had been produced in response to infection by the A/SD/97-like viruses.

Intraoperative three-dimensional reconstruction of power Doppler vascular images

We have developed a simple method for reconstructing a three-dimensional (3D) image in the operating room from sequentially scanned intraoperative two-dimensional (2D) power Doppler images using a personal computer and commercially available software. During three operations, 2 for cerebral aneurysm and 1 for cerebral tumor, intracranial vessel images were digitally transferred to a personal computer by freehand scanning over the dura mater or surface of the brain with a 7.5-MHz linear probe. A series of 2D images were converted to a smaller file, and 3D image was reconstructed with volume-rendering software. It took about 15 minutes to reconstruct of the initial 3D image. In the cases of cerebral aneurysm, the vessels connected to the lesion or running nearby were easily identified on the image. In the tumor case, the anatomical relation between the vascular structures and the tumor was clear. This simple 3D reconstruction method provides spatial information about intracranial vascular structures that is useful in intraoperative surgical planning.

Fluorescence detection of a new photosensitizer, PAD-S31, in tumour tissues and its use as a photodynamic treatment for skin tumours in dogs and a cat: a preliminary report

We describe here the detection by fluorescence of a new photosensitizer, PAD-S31, in tumours in dogs and cats and the effect of photodynamic therapy (PDT) by using PAD-S31 for skin tumours in two dogs and one cat. PAD-S31 is a hydrophilic photosensitizer that has two peaks at absorption wavelengths 406 and 665 nm in distilled water. In a preliminary experiment in mice transplanted with SCCVII and colon 26, PAD-S31 was retained in tumour tissues rather than in other organs. The tumours resected from dogs and cats after intravenous administration of PAD-S31 at a dose of 15 mg/kg emitted strong red fluorescence under light illumination of 402 nm wavelength. Animals given PAD-S31 showed no cutaneous photosensitivity under room light illumination. Irradiation at laser light 670 nm wavelength (fluence rate 150 mW/cm2 and total light dosage 150 J/cm2) on cutaneous mast cell tumours in dogs ( n=2 ) and a cutaneous basal cell tumour in a cat induced complete remission. These results suggest PAD-S31 could be a promising photosensitizer for use in a small animal veterinary practice.

Immunocytochemical localization of monoamine oxidase type B in enterochromaffin-like cells of rat oxyntic mucosa

We used immunohistochemistry to identify the localization of monoamine oxidase type B (MAOB) in the rat oxyntic mucosa. At light microscopic levels, MAOB-immunopositive cells were mostly located in the basal half of the oxyntic mucosa. By a double-labeling immunofluorescence method, it was shown that MAOB immunoreactivity was localized in almost all of histidine decarboxylase (HDC)-positive cells. Only a few MAOB-positive cells were negative for HDC. At electron microscopic levels, immunohistochemical reaction products of MAOB were detected on the mitochondrial outer membranes in cells that showed morphological characteristics of enterochromaffin-like (ECL) cells. These findings indicate that ECL cells contain MAOB in the rat. We provide a hypothesis that MAOB is involved in the inactivation mechanism of histamine that is released from ECL cells and activates parietal cells to secrete gastric acid.

Effects of orexin (hypocretin) on GIRK channels

Orexins (hypocretins) are recently discovered excitatory transmitters implicated in arousal and sleep. Yet, their ionic and signal transduction mechanisms have not been fully clarified. Here we show that orexins suppress G-protein-coupled inward rectifier (GIRK) channel activity, and this suppression is likely to lead to neuronal excitation. Cultured neurons from the locus coeruleus (LC) and the nucleus tuberomammillaris (TM) were used, as well as HEK293A cells transfected with GIRK1 and 2, either human orexin receptor type 1 (OX1R) or type 2 (OX2R), mu opioid receptor and GFP cDNAs. In GTPgammaS-loaded cells, orexin A (OXA, 3 microM) inhibited GIRK currents that had previously been activated by somatostatin (in LC cells), nociceptin (TM cells), or the mu opioid agonist DAMGO (HEK cells). In guanosine triphosphate (GTP)-loaded HEK cells, in which GIRK currents were not preactivated, OXA induced a biphasic response through both types of orexin receptors: an initial current increase and a subsequent decrease to below resting levels. Current-voltage (I-V) relationships revealed that both the OXA-induced and suppressed currents are inwardly rectifying with reversal potentials around EK. The OXA-induced initial current was partially pertussis toxin (PTX) sensitive and partially PTX insensitive, whereas the OXA-suppressed current was PTX insensitive. These data suggest that orexin receptors couple with more than one type of G-protein, including PTX-sensitive (such as Gi/o) and PTX-insensitive (such as Gq/11) G-proteins. The modulation of GIRK channels by orexins may be one of the cellular mechanisms for the regulation of brain nuclei (e.g., LC and TM) that are crucial for arousal, sleep, and appetite.

A gene for a Class II DNA photolyase from Oryza sativa: cloning of the cDNA by dilution-amplification

Ultraviolet radiation induces the formation of two classes of photoproducts in DNA-the cyclobutane pyrimidine dimer (CPD) and the pyrimidine [6-4] pyrimidone photoproduct (6-4 product). Many organisms produce enzymes, termed photolyases, which specifically bind to these lesions and split them via a UV-A/blue light-dependent mechanism, thereby reversing the damage. These photolyases are specific for either CPDs or 6-4 products. Two classes of photolyases (class I and class II) repair CPDs. A gene that encodes a protein with class II CPD photolyase activity in vitro has been cloned from several plants including Arabidopsis thaliana, Cucumis sativus and Chlamydomonas reinhardtii. We report here the isolation of a homolog of this gene from rice (Oryza sativa), which was cloned on the basis of sequence similarity and PCR-based dilution-amplification. The cDNA comprises a very GC-rich (75%) 5; region, while the 3; portion has a GC content of 50%. This gene encodes a protein with CPD photolyase activity when expressed in E. coli. The CPD photolyase gene encodes at least two types of mRNA, formed by alternative splicing of exon 5. One of the mRNAs encodes an ORF for 506 amino acid residues, while the other is predicted to code for 364 amino acid residues. The two RNAs occur in about equal amounts in O. sativa cells.

Two different inward rectifier K+ channels are effectors for transmitter-induced slow excitation in brain neurons

Substance P (SP) excites large neurons of the nucleus basalis (NB) by inhibiting an inward rectifier K(+) channel (Kir). The properties of the Kir in NB (KirNB) in comparison with the G protein-coupled Kir (GIRK) were investigated. Single-channel recordings with the cell-attached mode showed constitutively active KirNB channels, which were inhibited by SP. When the recording method was changed from the on-cell to the inside-out mode, the channel activity of KirNB remained intact with its constitutive activity unaltered. Application of Gbeta(1gamma2) to inside-out patches induced activity of a second type of Kir (GIRK). Application of Gbeta(1gamma2), however, did not change the KirNB activity. Sequestering Gbeta(1gamma2) with Galpha(i2) abolished the GIRK activity, whereas the KirNB activity was not affected. The mean open time of KirNB channels (1.1 ms) was almost the same as that of GIRKs. The unitary conductance of KirNB was 23 pS (155 mM [K(+)](o)), whereas that of the GIRK was larger (32-39 pS). The results indicate that KirNB is different from GIRKs and from any of the classical Kirs (IRKs). Whole-cell current recordings revealed that application of muscarine to NB neurons induced a GIRK current, and this GIRK current was also inhibited by SP. Thus, SP inhibits both KirNB and GIRKs. We conclude that the excitatory transmitter SP has two types of Kirs as its effectors: the constitutively active, Gbetagamma-independent KirNB channel and the Gbetagamma-dependent GIRK.

Semiquantitative analysis of corpus callosum injury using magnetic resonance imaging indicates clinical severity in patients with diffuse axonal injury

OBJECTIVE

To evaluate the hypothesis that the extent of corpus callosum injury indicates the depth of shearing lesions in the central brain structure and therefore relates to the clinical severity of diffuse axonal injury.

METHODS

A simple and objective procedure for semiquantitative analysis of magnetic resonance images (MRI)-the maximum signal intensity ratio (MSIR)-was employed prospectively in 21 patients with diffuse axonal injury but without apparent injury to the ventral pons. All were diagnosed using serial combination MRI scans of fluid attenuated inversion recovery (FLAIR) and T2* weighted gradient echo imaging during the initial two weeks after the injury. The signal intensity ratio between the two regions of interest-the corpus callosum and the normal appearing ventral pons-was calculated serially in mid-sagittal and parasagittal FLAIR image sections in each patient. The MSIR during the study period was determined as a semiquantitative index of corpus callosum injury in each patient. The correlations between MSIR and the duration of unconsciousness, Glasgow outcome scale at six months, and the presence of apparent midbrain injury were investigated.

RESULTS

The mean (SD) MSIR value was 1.12 (0.18) at 7.4 (3.1) days after the injury (n = 21). MSIR correlated strongly with the duration of unconsciousness (n = 19, R(2) = 0.74, p < 0.0001), and was higher in patients with both an unfavourable GOS outcome (p = 0.020) and apparent midbrain injury (p < 0.001).

CONCLUSIONS

MSIR, which is a simple and objective procedure for semiquantitative analysis of corpus callosum damage in diffuse axonal injury, correlated with clinical severity. A high MSIR value may indicate the presence of concomitant midbrain injury.

Leukotriene receptor antagonist, montelukast, can reduce the need for inhaled steroid while maintaining the clinical stability of asthmatic patients

BACKGROUND

Oral leukotriene receptor antagonists have been shown to have efficacy in chronic asthma.

OBJECTIVE

To determine whether the addition of montelukast could lead to a reduction in inhaled corticosteroid dose without a significant decrease in peak expiratory flow rate (PEFR).

METHODS

After a 4-week run-in period, 191 moderate-to-severe asthmatic patients whose asthma had been well controlled with daily inhaled corticosteroid therapy (beclometasone dipropionate 800 to 1600 micro g/day), were randomly assigned to one of two treatments - placebo (n = 98) or montelukast 10 mg once daily (n = 93) - for a 24-week, multicentre, double-blind, treatment period. At the beginning of the active treatment period, the daily dose of inhaled corticosteroid was halved in all of the patients. In addition, the inhaled corticosteroid dose was subsequently titrated every 8 weeks, based on PEFR, asthma symptoms and beta-agonist use.

RESULTS

After 8 weeks of a 50% reduction in inhaled corticosteroid use, morning PEFR increased by 5.3 +/- 32.3 L/min from baseline in patients receiving montelukast and significantly decreased by 6.9 +/- 29.0 L/min in those receiving placebo (P = 0.035). In addition, evening PEFR significantly decreased by 9.8 +/- 28.5 L/min (P = 0.003) in the placebo group, but was maintained in the montelukast group. In spite of a subsequent 50% reduction in the inhaled corticosteroid dose every 8 weeks, morning and evening PEFRs were maintained over the 24-week treatment period in the montelukast group; PEFR significantly decreased in the placebo group. There was a significant difference between the two groups with regard to morning PEFR, therapy score and asthmatic score at weeks 8, 16 and 24, as well as evening PEFR at week 8. However, the symptom scores were not significantly different between the two groups or within each group.

CONCLUSION

These data suggest that montelukast reduces the need for inhaled corticosteroids while maintaining asthma control over a 24-week period. Therefore, montelukast may be useful for long-term treatment in patients with asthma who require high doses of inhaled corticosteroids.

Antiproliferative activity induced by the somatostatin analogue, TT-232, in human pancreatic cancer cells

Somatostatin analogues have been developed as antiproliferative agents, but their administration as general antitumour agents is limited, mainly because of the wide distribution of somatostatin receptors throughout the human body. TT-232, a new somatostatin structural analogue, was reported to have tumour-selective antiproliferative activity without an antisecretory action. We examined whether TT-232 had antiproliferative activity in human pancreatic cancer cell lines, and compared its antiproliferative activity with that of RC-160 and other TT-232 derivatives. TT-232 inhibited the growth of all of the cell lines used in this study and induced apoptotic cell death. RC-160 showed no such growth inhibition. TT-232 also inhibited tumour formation in a xenograft model. A competitive binding assay was performed using the cell membrane fraction and 111In-DTPA-TT-232 in order to show the existence of a specific binding site on the cells. A specific binding site was detected in MIAPaCa-2 cells. It has been shown that the activation of protein tyrosine phosphatase (PTPase) is one of the main intracellular pathways responsible for somatostatinergic inhibition of cell growth. We found a significant PTPase stimulation after TT-232 administration using an immunoblot analysis assessing the level of protein tyrosine phosphorylation, and also a direct measurement of the PTPase activity. We also demonstrated that PTPase stimulation by TT-232 was involved in its antiproliferative activity as this activity was reversed by the addition of sodium orthovanadate, a PTPase inhibitor. Our results indicate that TT-232 could be a potentially useful therapeutic agent if these data are translated into clinical practice.

Contextual control of Pavlovian bidirectional occasion setting

Three pigeons were trained in a lighted context on a bidirectional occasion-setting task in which a tone feature (F) signaled food after the green keylight (L:G-, L:FG+) and no food after the red keylight (L:R+, L:FR-). They acquired the former feature-positive (F-P) discrimination and the latter feature-negative (F-N) discrimination at almost equal speed. Another three birds were trained with a F-P discrimination task in a light context (L:G-, L:FG+) and with a F-N discrimination task in a dark context (D:G+, D:FG-). The keylight was always green and two contextual conditions were changed randomly trial by trial. In this training, the F-P discrimination was acquired faster than the F-N discrimination. Then, all birds received a more complex amalgam contingency in which all eight types of trials were presented in the session (D:R-, D:G+, D:FR+, D:FG-, L:R+, L:G-, L:FR-, L:FG+). After they learned the amalgam training, the outcomes of two trial types were changed (D:R+, D:G-), but this treatment failed to reverse the pattern of responding in the remaining trial types.

Cyclobutane pyrimidine dimers are responsible for the vast majority of mutations induced by UVB irradiation in mammalian cells

The most prevalent DNA lesions induced by UVB are the cyclobutane pyrimidine dimers (CPDs) and the pyrimidine (6-4) pyrimidone photoproducts ((6-4)PPs). It has been a long standing controversy as to which of these photoproduct is responsible for mutations in mammalian cells. Here we have introduced photoproduct-specific DNA photolyases into a mouse cell line carrying the transgenic mutation reporter genes lacI and cII. Exposure of the photolyase-expressing cell lines to photoreactivating light resulted in almost complete repair of either CPDs or (6-4)PPs within less than 3 h. The mutations produced by the remaining, nonrepaired photoproducts were scored. The mutant frequency in the cII gene after photoreactivation by CPD photolyase was reduced from 127 x 10(-5) to 34 x 10(-5) (background, 8-10 x 10(-5)). Photoreactivation with (6-4) photolyase did not lower the mutant frequency appreciably. In the lacI gene the mutant frequency after photoreactivation repair of CPDs was reduced from 148 x 10(-5) to 28 x 10(-5) (background, 6-10 x 10(-5)). Mutation spectra obtained with and without photoreactivation by CPD photolyase indicated that the remaining mutations were derived from background mutations, unrepaired CPDs, and other DNA photopoducts including perhaps a small contribution from (6-4)PPs. We conclude that CPDs are responsible for at least 80% of the UVB-induced mutations in this mammalian cell model.

A novel synthetic Arg-Gly-Asp-containing peptide cyclo(-RGDf==V-) is the potent inhibitor of angiogenesis

Arg-Gly-Asp (RGD)-containing peptide is a ligand for integrin alpha(V)beta3 and acts as an angiogenic inhibitor. A novel cyclic RGD peptide, cyclo(-RGDf==V-) (f==V), was synthesized and its biological activities were characterized and compared with its analogs, cyclo(-RGDfV-) (fV) and cyclo(-RGDf-MeV-) (fMeV). It bound to integrin alpha(V)beta3 with almost the same affinity as the fV and fMeV analogs. All three compounds inhibited the adhesion and growth of HUVEC cells in a dose-dependent manner in vitro. Out of three, fMeV had the strongest effect, f==V was almost as strong as fMeV, and fV had the least effect. However, in vivo, f==V significantly decreased the intratumoral microvessel density (MVD) in the DLD-1 (human colon cancer cell) inoculated mice, while fMeV had little effect. These results suggest the potential usefulness of the cyclo(-RGDf==V-) as an antiangiogenic agent for clinical use in the future.

Magnetic compression anastomosis for benign obstruction of the common bile duct

Advances in interventional radiology have made possible magnetic compression anastomosis between the bile duct and the small intestine as a novel treatment. A 70-year-old man who had undergone subtotal gastrectomy for gastric cancer 2 years previously experienced recurring cholangitis with high fever and jaundice. Diagnostic evaluation subsequently demonstrated complete obstruction of the common bile duct which was attributed to recurrent cholangitis. A parent magnet was placed endoscopically into the afferent loop of the duodenum through the gastrojejunostomy with Billroth II reconstruction. The daughter magnet attached to a guide wire was placed in the obstructed common bile duct through a percutaneous transhepatic cholangiographic drainage tube. Two magnets were immediately attracted towards each other transmurally, and anastomosis was established on day 32 after the procedure. This novel method of magnetic compression anastomosis has the advantages of noninvasiveness and simplicity, as well as being a well-tolerated procedure for indications such as biliary obstruction.

Expression of METH-1 and METH-2 in pancreatic cancer

PURPOSE

METH-1/hADAMTS-1 and METH-2/hADAMTS-8 are recently identified genes that inhibit angiogenesis, and the murine homologue, ADAMTS-1, shows metalloproteinase function. Because the significance of METH-1 and METH-2 has not been determined in solid tumors, we examined the mRNA expressions of these molecules in pancreatic cancer and hepatocellular carcinoma (HCC).

EXPERIMENTAL DESIGN

METH-1 and METH-2 mRNA expressions were identified in six pancreatic cancer cell lines and were quantified by TaqMan reverse transcription-PCR in 18 paired samples of pancreatic cancer and surrounding noncancerous pancreas, and in 14 samples of pancreatic cancer. METH-1 mRNA expression was also examined in 16 pairs of HCC and cirrhotic liver. Vascularity was estimated by CD34 staining. The correlation between clinicopathological factors and METH-1 expression was additionally analyzed.

RESULTS

Four of six pancreatic cancer cell lines expressed METH-1, and 1/6 expressed METH-2. METH-1 was substantially expressed in both pancreatic cancer and noncancerous pancreas, but METH-2 was not. METH-1 expression in pancreatic cancer tissue was significantly lower than that in noncancerous pancreas (P = 0.002), and a similar result was obtained between HCC and cirrhotic liver (P = 0.003). METH-1 expression did not show a significant correlation with vascularity in pancreatic cancer or in HCC. However, pancreatic cancer with higher expression of METH-1 showed significantly severe lymph node metastasis or retroperitoneal invasion (P = 0.033 and P = 0.018, respectively) and worse prognosis (P = 0.038).

CONCLUSIONS

METH-1, which was initially reported to have a potent antiangiogenic effect, does not seem to be a predominant determinant of tumor vascularity in pancreatic cancer. Rather, METH-1 seems to be involved in progression of pancreatic cancer through local invasion and lymph node metastasis.

Influence of theophylline on activated lymphocytes and eosinophils in peripheral blood and sputum

The influence of a once-a-day sustained-release theophylline (Uniphyl) on lymphocytes and eosinophils in the peripheral blood and sputum of patients with bronchial asthma was investigated. The peripheral blood lymphocytes included CD4, CD8, CD25 and HLA-DR. The sputum lymphocytes and eosinophils included CD4, CD8, CD25 and HLA-DR, and EG2, respectively. The results revealed that theophylline administration did not affect the numbers of activated CD4 and CD8 T lymphocytes in peripheral blood. No significant change in the lymphocyte count was observed in sputum, but the eosinophil count in the sputum decreased significantly after theophylline administration. EG2-positive eosinophils also decreased in number. CD4+HLA-DR+ and CD4+CD25+ T lymphocytes were significantly decreased, whereas CD8+ T lymphocytes in the sputum were not significantly reduced in number. Respiratory function test showed that forced expiratory volume in 1 s was significantly increased after theophylline administration. The results suggest that a new once-a-day sustained-release theophylline formulation would be useful in the treatment of chronic respiratory tract inflammation.

PDT to monkey CNV with ATX-S10(Na): inappropriateness of early laser irradiation for selective occlusion

PURPOSE

There is controversy about which mode of laser irradiation, early irradiation with low-dose photosensitizer or late irradiation with high-dose, benefits the selective occlusion of choroidal neovascularization (CNV) in photodynamic therapy (PDT). In this study, using an amphiphilic photosensitizer, 13,17-bis (1-carboxypropionyl) carbamoylethyl-8-etheny-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetraethyl porphyrin sodium (ATX-S10(Na); Photochemical Inc., Okayama, Japan), photodynamic and adverse effects of early irradiation on CNV-bearing monkey eyes were investigated.

METHODS

Experimentally induced CNV lesions and normal retina were irradiated with a diode laser (670-nm wavelength) at a dose of 1 to 90 J/cm(2) at 1 to 19 minutes after intravenous injection of 2 mg/kg body weight of ATX-S10(Na). Vascular occlusion and CNV recurrence were evaluated by fluorescein and indocyanine green angiography and histologic analysis, until 4 weeks after irradiation.

RESULTS

Of 45 different conditions, 23 did not induce CNV closure, 20 provided both CNV occlusion and retinal vessel damage, and 2 achieved selective CNV occlusion without retinal vascular injury. Recurrence of CNV was induced in 19 of 22 CNV-occluding conditions. ATX-S10(Na) angiography showed that dyes were similarly distributed between normal vessels and CNV at early time periods after injection, whereas they were preferentially accumulated in CNV after 30 minutes.

CONCLUSIONS

In PDT with ATX-S10(Na), irradiation within 20 minutes of dye injection failed to induce selective CNV occlusion, probably because there is no significant difference in the biodistribution of dye between CNV and retinal vessels. It also caused frequent CNV recurrence after extensive inflammation in the irradiated retina.

Trehalose sensitivity in Drosophila correlates with mutations in and expression of the gustatory receptor gene Gr5a

Drosophila taste gene Tre is located on the distal X chromosome and controls gustatory sensitivity to a subset of sugars [1, 2]. Two adjacent, seven-transmembrane domain genes near the Tre locus are candidate genes for Tre. One (CG3171) encodes a rhodopsin family G protein receptor [3, 4], and the other (Gr5a) is a member of a chemosensory gene family encoding a putative gustatory receptor [5-7]. We carried out molecular analyses of mutations in Tre to elucidate their involvement in the gustatory phenotype. Here, we show that Tre mutations induced by P element-mediated genomic deletions disrupt Gr5a gene organization and the expression of Gr5a mRNA, while disruption of the CG3171 gene or its expression was not always associated with mutations in Tre. In flies with the spontaneous mutation Tre(01), both CG3171 and Gr5a mRNAs are transcribed. Coding sequences of these two candidate genes were compared among various strains. A total of three polymorphic sites leading to amino acid changes in CG3171 were not correlated with the gustatory phenotype. Among four nonsynonymous sites in Gr5a, a single nucleotide polymorphism leading to an Ala218Thr substitution in the predicted second intracellular loop cosegregated with Tre(01). Taken together, the mutation analyses support that Gr5a is allelic to Tre.