A case of duodenal papillary carcinoma complicated by repeated acute pancreatitis

We present a patient with duodenal papillary carcinoma who repeatedly developed acute pancreatitis preoperatively. The patient was a 65-year-old male. In February 1997, the patient consulted a local hospital due to vomiting, high fever, and jaundice. With the diagnosis of obstructive jaundice, percutaneous transhepatic biliary drainage (PTBD) was performed, revealing a distal bile duct obstruction. Because duodenal papillary carcinoma was diagnosed based on endoscopic findings, the patient was admitted to Kurume University Hospital. Hypotonic duodenography (HDG) disclosed a protruding lesion with an irregular surface in the descending part of the duodenum, resulting in a diagnosis of positive duodenal invasion (du1). Because computed tomography (CT) demonstrated a protruding lesion on the medial side of the second portion of the duodenum, positive pancreatic invasion (panc2) was diagnosed. On March 18 and April 22, sudden abdominal pain, leukocytosis, and an increase in serum amylase were noted. CT revealed that the pancreas was diffusely enlarged, showing an ill-defined boundary between the pancreas and adipose tissue and fluid collection. On CT, the lesion was evaluated as Grade 3 and moderate. For treatment, pancreatic enzyme inhibitors and antibiotics were intravenously injected. Peritoneal perfusion was concomitantly performed during the second treatment. Because symptoms remitted thereafter, a pylorus preserving pancreatoduodenectomy (PpPD) was carried out. The postoperative histologic examination revealed negative pancreatic invasion. Concerning the etiology of acute pancreatitis, not pancreatic invasion, but impaction of the liberated tumor mass in the common canal was considered responsible for the repeated pancreatitis because the tumor showed a cauliflower-like shape.

Increased angiotensin-converting enzyme activity in coronary artery specimens from patients with acute coronary syndrome

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors are effective in the secondary prevention of ischemic heart disease, but they do not reduce the rate of restenosis. Vascular ACE activity in the culprit coronary lesions of these patients, however, has never been quantified.

METHODS AND RESULTS

We measured the ACE activity of vascular tissue obtained by directional coronary atherectomy in patients with acute coronary syndrome (n=17) and in patients with stable ischemic heart disease (n=36), with and without restenosis. The ACE activity of the culprit coronary lesions was significantly increased in patients with acute coronary syndrome (0.87+/-0.12 nmol. min(-1). mg protein(-1); P:<0.01) but not in patients with ischemic heart disease with restenosis (n=11, 0.19+/-0.05 nmol. min(-1). mg protein(-1)) when compared with those patients with ischemic heart disease without restenosis (n=25, 0.20+/-0.05 nmol. min(-1). mg protein(-1)). There was no difference between the ACE activity of the coronary tissue of the in-stent (n=5) and stent-unrelated (n=6) restenosis patients (0.24+/-0.10 versus 0.15+/-0.04 nmol. min(-1). mg protein(-1)). Serum ACE activity did not differ significantly among the patients.

CONCLUSIONS

The present study demonstrates increased ACE activity in culprit lesions in acute coronary syndrome, indicating that enhanced ACE activity is related to the causative mechanism of active coronary lesions.

Transforming growth factor-beta/Smads signaling induces transcription of the cell type-restricted ankyrin repeat protein CARP gene through CAGA motif in vascular smooth muscle cells

Transforming growth factor (TGF)-beta plays a major role in the development of vascular diseases. Despite the pleiotropic effects of TGF-ss on vascular smooth muscle cells (VSMCs), only a few genes have been characterized as direct targets of TGF-beta in VSMCs. Cardiac ankyrin repeat protein (CARP) has been thought to be expressed exclusively in the heart. In the present study, we showed that CARP is expressed in the vasculature after balloon injury and in cultured VSMCs in response to TGF-beta. Analysis of a half-life of the cytoplasmic CARP mRNA levels and the transient transfection of the CARP promoter/luciferase gene indicates that the regulation of CARP expression is increased by TGF-beta at the transcriptional level. Transfection of expression vectors encoding Smads significantly activated the CARP promoter/luciferase activity. Deletion analysis and site-specific mutagenesis of the CARP promoter indicate that TGF-beta response element is localized to CAGA motif at -108 bp relative to the transcription start site. Electrophoretic mobility shift assays showed that the binding activity to the CAGA motif was increased in nuclear extracts of cultured VSMCs by TGF-beta. Cells transfected with adenovirus vector expressing CARP showed a significant decrease in DNA synthesis. Overexpression of CARP enhanced the TGF-beta-mediated inhibition of the DNA synthesis. These data indicate that CARP is a downstream target of TGF-beta/Smad signaling in VSMCs and suggest a role of CARP in mediation of the inhibitory effects of TGF-beta on the proliferation of VSMCs.

Clinicopathological evaluation of surgical treatment for early gallbladder cancer

We evaluated the therapeutic principles for early gallbladder cancer based on clinicopathological characteristics and outcomes in 27 patients encountered at the Kurume University Hospital between January, 1975 and December, 1999. Concerning the depth of wall penetration, 15 patients had mucosal cancers (m-cancers), and 12 patients muscularis propria cancers(mp-cancers). The gross patterns were lp (pedunculated) in 16 patients, ls (sessile) in 3 patients, IIa (flat elevated) in 4 patients, and IIb (flat) in 4 patients. The operative procedure used was cholecystectomy (C) in 12 patients, 4 of whom underwent lymph node dissection. Full-thickness cholecystectomy (FTC) was carried out in 3 patients, one of whom had lymph node dissection. Combination of C and gallbladder bed resection (GbBR) was performed in 7 patients, 6 of whom had lymph node dissection. Combination of C and bile duct resection (BDR), and lymph node dissection was performed in 1 patient. Combination of C and GbBR and BDR, and lymph node dissection was performed in 6 patients. All the patients who underwent lymph node dissection were negative for metastasis. Of the 27 patients, 2 underwent laparoscopic operation: one with m-cancer was 79 years old, and the other with mp-cancer 86 years old. In the m-cancers, no lymphatic, venous or perineural infiltration was observed. In contrast, in the mp-cancers, lymphatic and venous infiltration each were observed in 4 patients (33.3%), although no perineural infiltration was observed. A diagnosis of gallbladder cancer was made postoperatively in 6 patients, of whom 4 had the IIb pattern and all were complicated by gallstone, indicating the difficulty of diagnosing the IIb pattern. The 5-year survival rates for the m- and mp-cancers were as high as 90.9% and 80.8%, respectively. As a curative surgical technique for m- and mp-cancers, lymph node dissection should be performed in addition to FTC, GbBR, and BDR, in combination. When a postoperative histopathologic diagnosis of gallbladder cancer has been made, no second-look operation should be performed for m-cancers, but lymph node dissection of up to the second group should be performed for mp-cancers in a second-look operation.

Syncope in patients with atrial flutter during treatment with class Ic antiarrhythmic drugs

We describe 2 atrial flutter (AFL) patients with syncope during treatment with class Ic antiarrhythmic drugs. During the syncope, 1:1 atrioventricular (AV) conduction during AFL preceded a wide QRS tachycardia. The class Ic drugs, flecainide and pilsicainide, slowed the atrial rate, resulting in AFL with 1:1 AV conduction, and the width of the QRS complexes became wider during the tachycardia. Syncope was abolished after successful radiofrequency catheter ablation of the AFL. These potential proarrhythmic effects of the class Ic drugs should be taken into account in AFL patients, and concomitant use of beta-blocking agents would be critical to prevent proarrhythmias.

Effect of intestinal helminthiasis on nutritional status of schoolchildren

This study was conducted in a rural agricultural area in Siniloan, Republic of the Philippines. The subjects were the school children. The nutritional status of 58 children infected with helminthiasis (Ascaris lumbricoides and Trichuris trichiura) was compared with that of 19 uninfected controls. Prevalence of Ascaris and Trichuris was 40.3% and 71.4% respectively, and 36.4% of infected children had both Ascaris and Trichuris infections. Statistically significant evidence of an adverse effect of helminthiasis on serum albumin levels was found, but no child had inadequate levels of other nutrients. Although helminthic infections increase the level of immunoglobulin E (IgE) in children endemically exposed to these parasites, there was no significant difference in the serum IgE among Ascaris or Trichuris infected groups in this study.

VEGF is causative for pulmonary hypertension in a patient with Crow-Fukase (POEMS) syndrome

We report a case of Crow-Fukase (POEMS) syndrome associated with pulmonary hypertension (PH). In this case, the concentration of vascular endothelial growth factor (VEGF) was extremely high in the serum, and the levels of IL-1beta, IL-6, TNF-alpha, and thiamine, which were thought in past reports to be mediators of PH in Crow-Fukase syndrome, were normal. After prednisolone therapy, PH disappeared with a dramatic decrease in serum VEGF. Our results suggest that VEGF is closely correlated with PH in Crow-Fukase syndrome.

[Evaluation and improvement of medical and nursing service and caregiving for the elderly using MDS. 2. Diagnosis and symptoms, especially diseases causing care-requiring conditions]

Diagnoses recorded in the chapter E of Minimum Data Set (MDS) were analyzed in patients requiring care admitted in a geriatric hospital in Sapporo, Japan. They were classified as: A-diseases causing care-requiring conditions, B-their symptoms, and C-coexisting diseases requiring no care. Orthopedic diseases were not analyzed because they were not adequately recorded in MDS system. Class A diagnoses varied, but only five diagnoses were responsible for 3% or more of the total patients who required care. They were 1) Alzheimer's disease (AD), 2) Parkinson's disease, 3) dementia other than AD without neurological symptoms, 4) dementia other than AD with sequelae of stroke, and 5) sequelae of stroke without dementia. These diagnoses pooled represented over 90% of all patients. "Diagnoses and symptoms" in MDS were useful to 1) describe medical problems briefly in a predetermined format, 2) evaluate urgent or unstable conditions separately from stable diagnoses and symptoms, and 3) use common information by various professions, but have difficulties because 1) preselected diagnoses were few and unsuited to practices in Japan, 2) it is impossible to record a previous disease in the past that initiated the process leading to the present disabilities, and 3) it is also impossible to record the severities of the diseases and symptoms.

Analysis of relationship between Anopheles subpictus larval densities and environmental parameters using Remote Sensing (RS), a Global Positioning System (GPS) and a Geographic Information System (GIS)

Remote Sensing (RS), a Global Positioning System (GPS) and a Geographic Information System (GIS) were used to analyze relationship between Anopheles subpictus larval densities and environmental parameters in the Sekotong district on Lombok Island, Indonesia. Distance from the coast to larval habitats, season and surface water were considered as environmental parameters for determining An. subpictus larval densities. Japanese Earth Resources Satellite (JERS) Visible and Near Infrared Radiometer (VNIR) satellite imagery for the area acquired by National Space Development Agency of Japan (NASDA) were used to detect water, which could be used to characterize larval habitats. Data on larval sampling sites obtained from a GPS were entered into a GIS for mapping larval habitats to measure distance between the coast and the larval habitats. A GIS was used for overlaying of data coverages (i.e., water distribution from RS data and larval habitats coupled with data on larval densities) to identify factors that may explain the spatial distribution patterns of larval densities. An. subpictus larval densities were significantly associated with season and distance from the coast to larval habitats. The rainy season and the distance from the coast to larval habitats were critical environmental determinants for presence of An. subpictus larvae in the study. In this paper, we investigated relationship between An. subpictus larval densities and the environmental parameters using RS/GPS/GIS to determine if these tools could be used to predict larval densities.

Prevalence of antibodies to Toxoplasma gondii among urban and rural residents in the Philippines

A survey of antibodies to Toxoplasma gondii was carried out among residents in urban (Metro Manila) and rural (Mindoro and Leyte) areas in the Philippines. A total of 1,173 serum samples were examined for Toxoplasma antibody by an ELISA method. The overall seropositivity was 11.1% (n=904, 12.4% in males, 10.0% in females) in Metro Manila, 61.2% (n=152, 63.3% in males, 53.1% in females) in Mindoro, and 30.1% (n=113, 34.3% in males, 22.5% in females) in Leyte, indicating significantly higher (p<0.001) seropositivities in rural than urban settings. No significant differences in seropositivities were observed between males and females. In each group, seropositivity tended to increase with age of the subjects.

Serum levels of vascular endothelial growth factor dependent on the stage progression of lung cancer

STUDY OBJECTIVE

In lung cancer, vascular endothelial growth factor (VEGF) is an important cytokine and is correlated with tumor vessel density, malignant pleural effusions, and coagulation-fibrinolysis factors in vitro. We investigated the correlation between serum VEGF level and stage progression in lung cancer to study the predicted value of VEGF level. We also studied whether coagulation-fibrinolysis factors and PaO(2) levels, which are also important factors for the prediction of the clinical course, are correlated with VEGF.

METHODS

Forty-nine patients with lung cancer were investigated prospectively. VEGF levels of sera and malignant effusions, and plasma concentrations of coagulation-fibrinolysis factors were measured by enzyme-linked immunosorbent assay. We measured PaO(2) levels in all patients at rest.

RESULTS

Serum levels of VEGF were increased significantly according to stage progression. Additionally, plasma concentrations of D dimer, thrombin-antithrombin complex (TAT), and tissue plasminogen activator/plasminogen activator inhibitor type I complex were elevated significantly according to stage progression. The serum VEGF level had a significant positive correlation with the TAT and D dimer levels. Serum VEGF levels had a significant negative correlation with PaO(2) levels. The incidence of cerebral vascular disorder was significantly higher in the patients with systemic hypoxemia than in those without (p<0.05). Mean VEGF levels in malignant effusions in eight patients (five with pleural effusions, two with pericardial effusions, and one with both) were extremely high, especially in pericardial effusions ([mean +/- SD] pleural effusions, 531.9+/-285.4 pg/mL; pericardial effusion, 3,071.6+/-81.3 pg/mL).

CONCLUSION

We predict that in lung cancer, VEGF production and the abnormality of the coagulation-fibrinolysis system differ depending on the stage of progression of disease. Serum VEGF levels would be affected by PaO(2) levels in lung cancer.

[An autopsy case of neurogenic pulmonary edema due to suicide by hanging]

A 43-year-old man died of pulmonary edema after hanging himself. His cardiac function and renal function were normal. No aspiration, trauma, or overhydration was present, and high doses of catecholamine had not been administered. Autopsy findings revealed hypoxic brain damage, cerebral edema and pyknosis of nerve cells in the medulla oblongata. These findings resulted in a diagnosis of neurogenic pulmonary edema. To our knowledge, there have been no previous reports of neurogenic pulmonary edema due to airway obstruction.

Perinatal risk factors related to neurologic outcomes of term newborns with asphyxia at birth: a prospective study

OBJECTIVES

The incidence of poor neurologic outcomes was studied in term newborns who had suffered severe asphyxia at birth.

METHODS

Subjects were 152 newborns admitted to the NICU with a low Apgar score at 1 or 5 minutes. A 1-year prospective follow-up of neurological outcomes was carried out by a questionnaire survey concluded between April 1, 1996 and March 31, 1998.

RESULTS

1) The incidence of a poor neurologic outcome, including 15 neurologic sequelae and 6 deaths, was 13.8% among the subjects. 2) The risk of a poor outcome was increased by 13-fold in neonates with adverse neurological signs and 31-fold in those with hypoxic ischemic encephalopathy.

CONCLUSION

The incidence of poor neurologic outcome was very high among term infants with low Apgar scores. These infants were 10 times to 20 times more likely to die, or to survive with permanent disabilities, than were infants without low Apgar scores.

Increased serum level of vascular endothelial growth factor in pulmonary tuberculosis

Pulmonary tuberculosis, one of the granulomatous diseases, has few serological markers for its activity. Recently, an increased serum level of vascular endothelial growth factor (VEGF) was detected in patients with Crohn's disease, also a granulomatous disease. We hypothesized that VEGF might be associated with the pathogenesis of pulmonary tuberculosis. We investigated the serum level of VEGF in 43 patients with active pulmonary tuberculosis, 29 patients with old tuberculosis, and 25 patients with acute bronchitis. We were able to examine the serum VEGF levels every 3 mo for a period of 6 mo in seven patients with active pulmonary tuberculosis. We examined the presence of VEGF in the resected lungs of three patients with active pulmonary tuberculosis by immunohistochemistry. The serum levels of VEGF were significantly higher in patients with active pulmonary tuberculosis than in patients with old tuberculosis and acute bronchitis. The decrease in titer of serum VEGF paralleled the clinical improvement of patients with pulmonary tuberculosis. Immunohistochemical staining of the resected lungs demonstrated the presence of VEGF in alveolar macrophages surrounding the lesion. Therefore, VEGF may be associated with the pathogenesis of pulmonary tuberculosis.

Donor lymphocyte infusion for treatment of life-threatening respiratory syncytial virus infection following bone marrow transplantation

We describe two patients who developed respiratory syncytial virus (RSV) pneumonia after BMT. One died of RSV pneumonia after three courses of steroid pulse therapy. Surprisingly, RSV antigen was identified in the bronchoalveolar lavage fluid (BALF) obtained post mortem. Steroid pulse therapy might have suppressed anti-RSV immunity, leading to persistent RSV infection for more than 1 month. The other patient received donor lymphocyte infusions (DLI) for relapsed plasma cell leukemia, while having active RSV pneumonia. His respiratory condition improved after DLI, and RSV antigen disappeared in BALF and nasal swabs. DLI might be effective in cases of life-threatening RSV pneumonia.

[A clinicopathological study of pulmonary cryptococcosis--chest CT and pathologic correlation]

We reviewed the clinicopathological features in 12 patients (7 males and 5 females; mean age 54 yr) with pulmonary cryptococcosis. Eleven of the patients were asymptomatic and the disease was detected by chest radiograph abnormalities. The underlying systemic disease had been diagnosed as diabetes mellitus in two. Chest CT scans showed a solitary nodule in 9 of the 12 patients, multiple nodules in 2, and infiltration in 1. The nodular diameter was less than 2 cm in 10 of the 12. All nodules were located in the subpleural region. On the chest CT, cavitary nodules, scattered nodules, or both, and spiculated nodules were difficult to distinguish from pulmonary tuberculosis and primary lung cancer, respectively. According to McDonnell's pathological classification of pulmonary cryptococcosis, the resected 8 lungs revealed peripheral pulmonary granuloma in 5 and granulomatous pneumonia in 3. It is important to perform a pathological examination for the diagnosis of pulmonary cryptococcosis to avoid misdiagnosis as lung cancer or pulmonary tuberculosis.

Epitope-specific impairment of production of antibody against merozoite surface glycoprotein 1 of Plasmodium falciparum in symptomatic patients with malaria

We analyzed the relationships between levels of antibody specific for merozoite surface glycoprotein-1 (MSP1) of Plasmodium falciparum and clinical manifestations in humans. We prepared recombinant MSP1 proteins representing block 3 (M3), block 6 (M6), blocks 1-6 (M1/6), and block 17. When we divided the slide-positive individuals in Guadalcanal into symptomatic and asymptomatic groups, the former group showed lower IgG levels against M6 and block 17, but not against M3, than did the asymptomatic group (P < 0.01). The possibility of nonspecific suppression was unlikely, given that the levels of antibody against poliomyelitis virus observed in the two groups were almost the same. Among the IgG subclasses tested, production of cytophilic IgG3 seemed to be dominant. When we analyzed epitopes recognized by antibodies against block 17, a peptide (SSSNFLGIS) was preferentially recognized by sera from asymptomatic individuals. These results suggest that clinical symptoms occurring during falciparum malaria seem to be associated with the development of levels of antibody against particular epitopes on MSP1, which is under the control of an immunoregulatory mechanism.

Schnurri interacts with Mad in a Dpp-dependent manner

BACKGROUND

Decapentaplegic (Dpp) is a member of the transforming growth factor-beta superfamily. Dpp governs various developmental processes in Drosophila through the transcriptional regulation of a variety of genes. Signals of Dpp are transmitted from the cell membrane to the nucleus by Medea and Mad, both belonging to the Smad protein family. Mad was shown to bind to the Dpp-responsive element in genes such as vestigial, labial, and Ultrabithorax. The DNA binding affinity of Smad proteins is relatively low, and requires other nuclear factor(s) to form stable DNA binding complexes. schnurri (shn) was identified as a candidate gene acting downstream of Dpp receptors, but its relevance to Mad has remained unknown.

RESULTS

We characterized the biochemical functions of Shn. Shn forms homo-oligomers. Shn is localized in the nucleus, and is likely to have multiple nuclear localizing signals. Finally, we found that Shn interacts with Mad in a Dpp-dependent manner.

CONCLUSIONS

The present results argue that Shn may act as a nuclear component of the Dpp signalling pathway through direct interaction with Mad.

Clinical investigation of pulmonary Mycobacterium avium complex infection in human T lymphotrophic virus type I carriers

BACKGROUND

Little is known about pulmonary Mycobacterium avium complex (MAC) infection in human T lymphotrophic virus type I (HTLV-I) carriers. A study was undertaken to investigate and clarify the characteristics of pulmonary MAC infection in these subjects.

METHODS

Twenty nine patients with pulmonary MAC infection without any underlying pulmonary disorder were investigated. The clinical features and radiographic appearance of HTLV-I carriers and non-carriers were compared and the bronchoalveolar lavage (BAL) fluid of these 29 patients and eight normal female control subjects was analysed.

RESULTS

The prevalence of the HTLV-I carrier state in patients with pulmonary MAC infection was 34.5% (10/29) compared with 16.7% (529/3169) among all patients admitted to our department between 1994 and 1998 (odds ratio (OR) 2.63, 95% confidence interval (CI) 1.21 to 5.68). The HTLV-I carriers were all women and all had clinical symptoms, but they did not show systemic dissemination. Peripheral multifocal bronchiectasis with nodular shadowing was seen frequently on the chest computed tomographic (CT) scans of HTLV-I carriers. The area of the pulmonary lesions was more extensive than in non-carriers (p<0.05). White blood cell (WBC) counts and C reactive protein (CRP) levels on admission were significantly lower in HTLV-I carriers than in non-carriers (WBC: difference (D) = 1565/microl, 95% CI -68.9 to 3198.4/microl; CRP: D = 1.8 mg/dl, 95% CI -0.35 to 3.89 mg/dl). The concentrations of neutrophil elastase (NE) and interleukin (IL)-8 in BAL fluid were significantly higher in HTLV-I carriers than in non-carriers (NE: D = 1342 microg/l, 95% CI 704 to 1980.3 microg/l; IL-8: D = 304.5 pg/ml, 95% CI 89.7 to 519. 4 pg/ml).

CONCLUSIONS

Pulmonary MAC infection causes more diffuse and widespread lesions in HTLV-I carriers than in non-carriers.

BMP type II receptor is required for gastrulation and early development of mouse embryos

Bone morphogenetic proteins (BMPs), members of the transforming growth factor-beta superfamily, play a variety of roles during mouse development. BMP type II receptor (BMPR-II) is a type II serine/threonine kinase receptor, which transduces signals for BMPs through heteromeric complexes with type I receptors, including activin receptor-like kinase 2 (ALK2), ALK3/BMPR-IA, and ALK6/BMPR-IB. To elucidate the function of BMPR-II in mammalian development, we generated BMPR-II mutant mice by gene targeting. Homozygous mutant embryos were arrested at the egg cylinder stage and could not be recovered at 9.5 days postcoitum. Histological analysis revealed that homozygous mutant embryos failed to form organized structure and lacked mesoderm. The BMPR-II mutant embryos are morphologically very similar to the ALK3/BMPR-IA mutant embryos, suggesting that BMPR-II is important for transducing BMP signals during early mouse development. Moreover, the epiblast of the BMPR-II mutant embryo exhibited an undifferentiated character, although the expression of tissue-specific genes for the visceral endoderm was essentially normal. Our results suggest that the function of BMPR-II is essential for epiblast differentiation and mesoderm induction during early mouse development.

Intracellular signaling of the TGF-beta superfamily by Smad proteins

TGF-beta is a potent inhibitor of cell growth, and accumulating evidence suggests that perturbation of the TGF-beta signaling pathway leads to tumorigenesis. Smads are recently identified proteins that mediate intracellular signaling of the TGF-beta superfamily. Smads 2 and 3 are phosphorylated by the TGF-beta type I receptor. Smad4 was originally identified as a candidate tumor suppressor gene in pancreatic cancers. Smads 2 and 3 form complexes with Smad4 upon TGF-beta stimulation. The heteromeric Smad complexes translocate into the nucleus, where they activate expression of target genes. Our recent study demonstrated that Smads exist as monomers in the absence of TGF-beta. Smads 2 and 3 form homo- as well as hetero-oligomers with Smad4 upon ligand stimulation. Both homo-oligomers and hetero-oligomers directly bind to DNA, suggesting that the signaling pathway of Smads may be multiplex. Smads 2 and 3 associate with transcriptional coactivators such as p300 in a ligand-dependent manner, p300 enhances transactivation by TGF-beta, suggesting that coactivators link Smads to the basal transcriptional machinery. A missense mutation of Smad2 identified in colorectal and lung cancers was introduced to Smad3. The mutant, Smad3(DE), blocked the activation of wild-type Smad2 and Smad3. Thus, the missense mutation not only disrupts the function of the wild-type Smad but also creates a dominant-negative Smad, which could actively contribute to oncogenesis.

Smad6 is a Smad1/5-induced smad inhibitor. Characterization of bone morphogenetic protein-responsive element in the mouse Smad6 promoter

Smad6 is an inhibitory Smad that is induced by bone morphogenetic proteins (BMPs) and interferes with BMP signaling. We have isolated the mouse Smad6 promoter and identified the regions responsible for transcriptional activation by BMPs. The proximal BMP-responsive element (PBE) in the Smad6 promoter is important for the transcriptional activation by BMPs and contains a 28-base pair GC-rich sequence including four overlapping copies of the GCCGnCGC-like motif, which is a binding site for Drosophila Mad and Medea. We generated a luciferase reporter construct (3GC2-Lux) containing three repeats of the GC-rich sequence derived from the PBE. BMPs and BMP receptors induced transcriptional activation of 3GC2-Lux in various cell types, and this activation was enhanced by cotransfection of BMP-responsive Smads, i.e. Smad1 or Smad5. Moreover, direct DNA binding of BMP-responsive Smads and common-partner Smad4 to the GC-rich sequence of PBE was observed. These results indicate that the expression of Smad6 is regulated by the effects of BMP-activated Smad1/5 on the Smad6 promoter.

In-vitro and in-vivo antibiotic susceptibilities of Lyme disease Borrelia isolated in China

The antibiotic susceptibilities of seven Borrelia burgdorferi sensu lato isolates from Ixodes persulcatus in China were examined by in-vitro microdilution minimum inhibition concentration (MIC) and macrodilution minimum bactericidal concentration (MBC) methods. All isolates tested were susceptible to amoxicillin, erythromycin, and minocycline. The MICs of these drugs for the Chinese isolates were 0.025-0.1 microg/ml, <0.012-0.05 microg/ml, and <0.012-0.05 microg/ml, respectively. The MBCs were 0.1-0.39 microg/ml, <0.012-0.2 microg/ml, and 0.025-0.39 microg/ml, respectively. The in-vivo antimicrobial susceptibilities of the Chinese Borrelia isolates to two test drugs, amoxicillin and minocycline, were evaluated using ddY mice. Mice were infected by subcutaneous inoculation into the right hind footpad. When infection was confirmed, the mice were treated by subcutaneous injection of the test drugs into the back. Amoxicillin and minocycline, which possessed high in-vitro activities against Lyme disease Borrelia, provided good protection against borreliosis in this animal model. Higher doses of these drugs resulted in elimination of the Lyme disease spirochete from all animals receiving this course of treatment. The 50% curative doses (CD50) of amoxicillin and minocycline were 8.7 mg/kg and 3.1 mg/kg, respectively. This suggested that amoxicillin and minocycline could be useful for the treatment of Chinese Borrelia infection.

Competitive reverse transcription-polymerase chain reaction assay for quantification of human multidrug resistance 1 (MDR1) gene expression in fresh leukemic cells

We have analyzed MDR1 gene expression in 69 clinical samples obtained from 64 patients with leukemic hematologic malignancies by using a competitive reverse transcription-polymerase chain reaction assay with a heterologous competitor RNA. To exclude a false-positive result caused by concomitant normal lymphocytes that physiologically express MDR1, in samples we determined a cut-off value of 8 amol MDR1 transcript per microgram of RNA by simultaneous measurement of rhodamine 123 dye efflux either in lymphocyte or gated leukemic cell populations. Consequently, 23 of 69 samples were concluded to be MDR1-positive in leukemic cells per se. The MDR1 expression rate was significantly correlated with factors such as a history of preceding chemotherapy, elder age of the patient, and certain disease types (eg, leukemia progressed from myelodysplastic syndrome). Moreover, the complete response rate after chemotherapy was significantly higher in MDR1-negative patients than in MDR1-positive patients (52% vs 17%, respectively; P = .01). The assay established will enable the quantification of MDR1 gene expression in blood samples from patients with leukemic hematologic malignancies and will be applicable to clinical laboratories as a routine test.