Two cases of lichen planus pigmentosus presenting with a linear pattern

We report two cases of lichen planus pigmentosus (LPP) that developed in a unilateral linear pattern. The patients presented with unilateral linear brown macules on the extremities. Skin biopsy showed orthokeratosis, basal hydropic degeneration with scarce lymphohistiocytic infiltrates, and numerous melanophages in both patients. These patients, to the best of our knowledge, are the first cases of LPP presenting with a linear pattern. LPP should be considered in the differential diagnosis of linear hyperpigmented skin lesions.     

Altered expression of G1 regulatory proteins in human soft tissue sarcomas

CONTEXT: Soft tissue sarcomas constitute a heterogeneous group of tumors for which tumorigenesis is not fully understood. Altered cell-cycle regulation may underlie the development and/or progression of human malignancies. However, data concerning the occurrence of cell-cycle aberrations in soft tissue sarcomas are very limited. OBJECTIVES: To detect the abnormal features of cell-cycle regulatory proteins in soft tissue sarcomas and to determine the potential role of these proteins in clinical behavior. DESIGN: The p53 and Rb-cyclin D pathways were investigated by immunohistochemical studies of p53, mdm2, pRb, p16, cyclin D1, and cdk4 proteins, respectively. RESULTS: Of the 67 sarcomas analyzed, nuclear accumulation of p53 was detected in 25 samples (37%), and overexpression of mdm2 was found in 16 samples (24%). Both p53 and mdm2 expression correlated with tumor grade. Abnormalities involving the Rb-cyclin D pathway were identified in all of the tumors by the altered expression of either pRb (72%) or p16 (94%). Fourteen (21%) and 64 (96%) cases demonstrated cyclin D1 or cdk4 expression, respectively. Overexpression of cyclin D1 showed an association with pRb and p53. There was no correlation between pRb, p16, cyclin D1, or cdk4 and tumor grade or relapse. CONCLUSION: Disturbance in the cell-cycle regulatory system involving the p53 pathway and the Rb-cyclin D pathway is relatively frequent in soft tissue sarcomas and may be a contributing factor in the tumorigenesis of these tumors. The alterations in the Rb-cyclin D pathway probably constitute an early event, whereas the abnormalities in the p53 pathway seem to be involved in tumor progression. It is noteworthy that cyclin D1 may play a key role in linking both pathways.     

Organ distribution of severe acute respiratory syndrome (SARS) associated coronavirus (SARS-CoV) in SARS patients: implications for pathogenesis and virus transmission pathways

We previously identified the major pathological changes in the respiratory and immune systems of patients who died of severe acute respiratory syndrome (SARS) but gained little information on the organ distribution of SARS-associated coronavirus (SARS-CoV). In the present study, we used a murine monoclonal antibody specific for SARS-CoV nucleoprotein, and probes specific for a SARS-CoV RNA polymerase gene fragment, for immunohistochemistry and in situ hybridization, respectively, to detect SARS-CoV systematically in tissues from patients who died of SARS. SARS-CoV was found in lung, trachea/bronchus, stomach, small intestine, distal convoluted renal tubule, sweat gland, parathyroid, pituitary, pancreas, adrenal gland, liver and cerebrum, but was not detected in oesophagus, spleen, lymph node, bone marrow, heart, aorta, cerebellum, thyroid, testis, ovary, uterus or muscle. These results suggest that, in addition to the respiratory system, the gastrointestinal tract and other organs with detectable SARS-CoV may also be targets of SARS-CoV infection. The pathological changes in these organs may be caused directly by the cytopathic effect mediated by local replication of the SARS-CoV; or indirectly as a result of systemic responses to respiratory failure or the harmful immune response induced by viral infection. In addition to viral spread through a respiratory route, SARS-CoV in the intestinal tract, kidney and sweat glands may be excreted via faeces, urine and sweat, thereby leading to virus transmission. This study provides important information for understanding the pathogenesis of SARS-CoV infection and sheds light on possible virus transmission pathways. This data will be useful for designing new strategies for prevention and treatment of SARS.     

情境-达标式教学模式在胸心外科临床见习教学中的尝试

“情境-达标”式教学模式的核心是在教学过程中,只有创设更为适宜的教学情境,才能更加有效地达成教学目标[1]。胸心外科是一门涉及面广泛、较抽象、繁琐、难以理解的学科,如何使医学生在临床见习阶段很好地学会从理论到实际应用的转换,培养其分析问题、解决问题的能力,无疑是临     

An element downstream of the transcription start site is required for activation of Bombyx mori nucleopolyhedrovirus bro-c promoter

Bombyx mori nucleopolyhedrovirus (BmNPV) contains five baculovirus repeated ORF (bro) genes. We have previously reported that all of these genes (bro-a, b, c, d and e) are transcribed as early genes and require viral factor(s) for their expression. In this study, we investigated the mechanism of promoter activation of the bro-c gene. Transient expression assays using genomic libraries of BmNPV indicated that the baculoviral trans-regulator IE-1 is responsible for activating the bro-c promoter. To identify essential site(s) for promoter activation, mutations were introduced to the promoter region of bro-c. Interestingly, it was shown that the pentanucleotide sequence CACGC located 30 nucleotides downstream of the RNA start site was essential for bro-c promoter activation. In addition, the RNA start site and the spacing between the RNA start site and CACGC were also required for promoter activation. By introducing a CACGC sequence into the corresponding region of the bro-b promoter, which is not normally trans-activated by IE-1, we demonstrated that this pentanucleotide motif has the ability to confer trans-activation by IE-1 on a promoter. Gel retardation experiments also showed a sequence-specific DNA binding protein induced by baculovirus infection interacts with the CACGC motif.     

Defects in the differentiation and function of bone marrow-derived dendritic cells in non-obese diabetic mice

Due to their high immunostimulatory ability as well as the critical role they play in the maintenance of self-tolerance, dendritic cells have been implicated in the pathogenesis of autoimmune diseases. The non-obese diabetic (NOD) mouse is an animal model of autoimmune type 1 diabetes, in which pancreatic beta cells are selectively destroyed mainly by T cell-mediated immune responses. To elucidate initiation mechanisms of beta cell-specific autoimmunity, we attempted to generate bone marrow-derived dendritic cells from NOD mice. However, our results showed low proliferative response of NOD bone marrow cells and some defects in the differentiation into the myeloid dendritic cells. NOD dendritic cells showed lower expressions of MHC class II, B7-1, B7-2 and CD40, compared with C57BL/6 dendritic cells. In mixed lymphocyte reactions, stimulatory activities of NOD dendritic cells were also weak. Treatment with LPS, INF-gamma and anti-CD40 stimulated NOD dendritic cells to produce IL-12p70. The amount of IL-12, however, appeared to be lower than that of C57BL/6. Results of the present study indicated that there may be some defects in the development of NOD dendritic cells in the bone marrow, which might have an impact on the breakdown of self tolerance.     

Glycosylation is not required for the fusion activity of the G protein of vesicular stomatitis virus in insect cells

The gene encoding the complete glycoprotein of vesicular stomatitis virus (VSV, Indiana serotype G protein) with potential asparagine-linked glycans at amino acid residues 179 and 338 was inserted into a baculovirus transfer vector pAcYM1, derived from the nuclear polyhedrosis virus of Autographa californica (AcNPV). The gene was placed under the control of the AcNPV polyhedrin promotor and expressed by the derived recombinant viruses to high levels in Spodoptera frugiperda cell lines. The principal product was the glycosylated version of the G protein, although some alternative (including probable degradation) forms of the protein were also observed. Similar recombinant viruses were prepared with deletion of one, the other, or both glycosylation sites of the VSV G protein. All forms expressed VSV G protein derivatives and mediated cell fusion and the production of syncytia at low pH. The fusogenic properties of the VSV G protein expressed on the surface of insect cells was prevented using anti-VSV sera, or by elevating the pH above 6.2. A reduction of the pH to 5.5, or 5.0, accelerated the rate of syncytia formation.     

Secondary amenorrhea caused by hydrocephalus due to aqueductal stenosis : report of two cases

Amenorrhea is rarely presented as a manifestation of endocrinological disturbances in patients of chronic hydrocephalus. We describe two cases of secondary amenorrhea caused by hydrocephalus due to aqueductal stenosis. Two female patients of age 30 and 20 yr presented with amenorrhea and increasing headache. Magnetic resonance images revealed marked, noncommunicating hydrocephalus without any tumorous lesion. In one patient, emergent extraventricular drainage was necessary because of progressive neurological deterioration. Each patient underwent surgical intervention for the hydrocephalus-ventriculoperitoneal shunt and endoscopic third ventriculostomy. Both resumed normal menstruation continuing so far with further normal menstrual bleeding. These two cases and others reported in the literature indicated that the surgical intervention for hydrocephalus resolves amenorrhea in all the cases of amenorrhea due to hydrocephalus. The suspected role of the surgery is the correction of increased intracranial pressure, which is an important pathogenetic factor in the development of amenorrhea.     

A case of minute intraductal papillary mucinous tumor of the pancreas presenting with recurrent acute pancreatitis

Intraductal papillary mucinous tumor (IPMT) of the pancreas, a lesion consisting of mucin-producing cells with neoplastic potential, is characterized by duct ectasia, mucin hypersecretion, often extensive papillary intraductal growth, varying degrees of cytologic atypia, and relatively indolent growth. The clinical presentation of IPMT of the pancreas is characterized by chronic or recurrent attacks of abdominal discomfort often in association with low level pancreatic enzyme elevations. Less commonly these lesions may be detected as asymptomatic radiographic abnormalities. Interestingly, a case of a minute IPMT (2 mm in height and 7 mm in length, adenoma) in the main pancreatic duct presenting with acute pancreatitis in a 55 year-old man has been reported in the Japanese literature. Recently, we also experienced a case of a minute IPMT in a branch pancreatic duct causing repeated bouts of acute pancreatitis in a 75 year-old man. A filling defect at the neck of the main pancreatic duct seen on an endoscopic retrograde pancreatogram performed after recovery of the second attack of acute pancreatitis led the patient to undergo an exploratory laparotomy. After a near-total pancreatectomy was carried out, a minute (3 x 7 mm) IPMT of borderline malignancy was discovered in a branch duct at the head portion near the pancreatic neck without any lesions in the main pancreatic duct. Surprisingly, despite the resective surgery the patient died of carcinomatosis 8.5 months after the operation. We herein report a case of a minute but aggressive IPMT of the pancreas with a review of the literature.