Isolation and characterization of restriction endonuclease in Plesiomonas shigelloides and Aeromonas species

Five restriction endonucleases (ENases) and one ENase were found in a screen of 196 strains of Plesiomonas shigelloides and 147 strains of Aeromonas species. Plesiomonas and Aeromonas species are classified as Vibrionaceae, identified as food-poisoning bacteria, are closely genetically related to each other, and their ENases producing abilities have not bee reported. ENases were detected at relatively low frequencies in these species as compared to those in other species, such as Salmonella species and Vibrio parahaemolyticus. All Enases were shown to be isoschizomers of already known ENases. One of the Plesiomonas ENases, designated PshBI, recognizing the sequence 5'-AT/TAAT-3' should be useful, since PshBI ENase is produced at a high yield of 7000 units/g of wet cells. The specificities of other ENases are also described in this paper.

HLA class I antigens in Japanese patients with melanoma

In this study, we analyzed the frequencies of human leukocyte antigen (HLA) class I alleles in 110 Japanese patients with melanoma using serological methods, and compared such frequencies with clinical parameters. As expected, frequencies of HLA allele distribution in patients with melanoma reflected the frequencies observed in the normal Japanese population. Because these are different from populations belonging to other races (e.g., white), it followed that the HLA allele distribution in melanoma patients varies among different races. This differences may have significant implications for T-cell-mediated, HLA-restricted therapeutic modalities. No significant associations between HLA and clinical parameters were noted in this study. This report may help design future clinical trials involving therapeutic approaches based on HLA-restricted mechanisms.

Enhanced expression of tissue inhibitors of metalloproteinases in human colorectal tumors

Matrix metalloproteinases (MMP), such as 72 kDa type IV collagenase (MMP-2) and 92 kDa type IV collagenase (MMP-9), play an important role in tumor invasion and metastasis. Tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) are specific inhibitors of MMP. To evaluate the expression of TIMP-1, TIMP-2, MMP-2, and MMP-9 in human colorectal cancer, surgical specimens of primary colorectal cancer (66 cases) and liver metastases (10 cases) were examined by Northern and dot-blot hybridization. The levels of TIMP-1, MMP-2 and MMP-9 mRNA were significantly higher in primary colorectal cancers than in their adjacent normal tissues, and those of the mRNAs for all four genes were significantly higher in liver metastases than in normal colorectal tissues. Higher levels of TIMP-1 mRNA were positively correlated with lymph node metastasis and the five-year survival, and higher levels of TIMP-1 and TIMP-2 mRNA were positively correlated with the Dukes classification. Our findings suggest that the expression of TIMP-1 and TIMP-2 is closely correlated with the progression of human colorectal cancer.

Cutaneous metastases from pancreatic cancer

Cutaneous metastases originating from pancreatic cancer are relatively rare. Five cases of metastatic pancreatic cancer to the skin are presented and discussed with a review of 17 previous case reports. In 20 cases, the cutaneous metastases were present prior to the diagnosis of pancreatic cancer. The most common site of cutaneous metastases originating from pancreatic cancer was the umbilicus. Although such cases are rare, it is important to note that metastatic lesions in the skin may be the first sign and one type of distant metastases originating from pancreatic cancer.

Translocation of PKN from the cytosol to the nucleus induced by stresses

Effects of environmental stresses on the subcellular localization of PKN were investigated in NIH 3T3, BALB/c 3T3, and Rat-1 cells. The immunofluorescence of PKN resided prominently in the cytoplasmic region in nonstressed cells. When these cells were treated at 42 degrees C, there was a time-dependent decrease of the immunofluorescence of PKN in the cytoplasmic region that correlated with an increase within the nucleus as observed by confocal microscope. After incubation at 37 degrees C following beat shock, the immunofluorescence of PKN returned to the perinuclear and cytoplasmic regions from the nucleus. The nuclear translocation of PKN by heat shock was supported by the biochemical subcellular fractionation and immunoblotting. The nuclear localization of PKN was also observed when the cells were exposed to other stresses such as sodium arsenite and serum starvation. These results raise the possibility that there is a pathway mediating stress signals from the cytosol to the nucleus through PKN.

The differential diagnosis of pancreatic cysts by MR imaging

BACKGROUND/AIM

The usefulness of magnetic resonance imaging (MR imaging) in the differential diagnosis of cystic lesions of the pancreas was assessed.

METHODS AND MATERIALS

Pseudocyst was present in 9 patients, retention cyst in 4, simple cyst in 2, serous cystadenoma in 1, mucinous cystadenoma in 6, mucinous cystadenocarcinoma in 6. The relative signal intensity (SI) of each cystic lesion on MR imaging was assessed in comparison with that of the liver.

RESULTS

It was difficult to distinguish the cystic types from each other based on the SI on MR images. Insofar as mucinous cystic tumors, those containing gelatinous mucin showed higher SI on T1-weighted images than those containing mucinous but watery fluid. five of the 6 mucinous cystic tumors containing gelatinous mucin were histologically malignant, whereas all except one those containing watery fluid were benign.

CONCLUSIONS

Our results suggest that the SI on T1-weighted images may be useful in distinguishing malignant from benign mucinous cystic tumors.

PKN associates and phosphorylates the head-rod domain of neurofilament protein

PKN is a fatty acid-activated serine/threonine kinase that has a catalytic domain highly homologous to that of protein kinase C in the carboxyl terminus and a unique regulatory region in the amino terminus. Recently, we reported that the small GTP-binding protein Rho binds to the amino-terminal region of PKN and activates PKN in a GTP-dependent manner, and we suggested that PKN is located on the downstream of Rho in the signal transduction pathway (Amano, M., Mukai, H., Ono, Y., Chihara, K., Matsui, T., Hamajima, Y., Okawa, K., Iwamatsu, A., and Kaibuchi, K. (1996) Science 271, 648-650; Watanabe, G., Saito, Y., Madaule, P., Ishizaki, T., Fujisawa, K., Morii, N., Mukai, H., Ono, Y. Kakizuka, A., and Narumiya, S. (1996) Science 271, 645-648). To identify other components of the PKN pathway such as substrates and regulatory proteins of PKN, the yeast two-hybrid strategy was employed. By this screening, a clone encoding the neurofilament L protein, a subunit of neuron-specific intermediate filament, was isolated. The amino-terminal regulatory region of PKN was shown to associate with the head-rod domains of other subunits of neurofilament (neurofilament proteins M and H) as well as neurofilament L protein in yeast cells. The direct binding between PKN and each subunit of neurofilament was confirmed by using the in vitro translated amino-terminal region of PKN and glutathione S-transferase fusion protein containing the head-rod domain of each subunit of neurofilament. PKN purified from rat testis phosphorylated each subunit of the native neurofilament purified from bovine spinal cord and the bacterially synthesized head-rod domain of each subunit of neurofilament. Polymerization of neurofilament L protein in vitro was inhibited by phosphorylation of neurofilament L protein by PKN. The identification and characterization of the novel interaction with PKN may contribute toward the elucidation of mechanisms regulating the function of neurofilament.

Adult T-cell leukaemia/lymphoma with multiple integrations of human T-cell lymphotropic virus type I proviral DNA: differing clinical features are linked to varied proviral integration

Multiple integrations of human T-cell lymphotropic virus type I (HTLV-I) proviral DNA are occasionally found in tumor cells from patients with adult T-cell leukaemia/lymphoma (ATL). However, the clinical implications of multiple integrations of HTLV-I in ATL have not been well established. We studied 95 patients with ATL to elucidate the relationship between the multiple integrations of HTLV-I and the clinical characteristics. The proviral DNA of HTLV-I was examined by standard Southern blot analysis using the probe of an entire HTLV-I genome and the endonucleases with or without cleavage sites within the provirus. Multiple integrations of HTLV-I were detected in eight patients as extraordinary multiple bands; five patients showed multiple bands of the same intensity, and the remaining three showed multiple bands of differing intensities. The patients were divided into two groups based on these band patterns. One group was considered to exhibit one tumour cell clone carrying multiple copies of the provirus, whereas the other was considered to exhibit multiple tumour cell clones, each carrying one copy of the provirus. The former group of patients manifested a highly aggressive clinical course with frequent peculiar organ infiltrations, including the retina, uvea and muscle, along with the presence of large peripheral leukaemic T cells having flower-like nuclei. The latter group demonstrated an indolent clinical course with skin lesions or small leukaemic T cells having cleaved or lobulated nuclei. These findings suggest that the pattern of multiple HTLV-integrations into the tumor cell(s) has clinical implications in ATL. This may help to explain the heterogeneity of this disease.

Laparoscopic repair of a colonic perforation sustained during colonoscopy

A patient who sustained a colonic perforation during therapeutic colonoscopy was treated successfully by laparoscopic repair. Laparoscopy was performed 5 h after polypectomy. Fecal matter was not identified in the peritoneal cavity. Local peritonitis was mild. The laceration was oversewn with five sutures using the extracorporeal endoscopic knot technique. The appendix epiploica was then anchored over the lesion. The postoperative recovery was rapid and uneventful. Laparoscopic surgery may become a useful tool for the safe, effective, and minimally invasive management of iatrogenic colonic perforation.

Detection by polymerase chain reaction of wild-type measles virus genome in the cerebrospinal fluid of a patient with SSPE who had received measles vaccine

BACKGROUND

Previous studies have reported that approximately 4-5% of patients with subacute sclerosing panencephalitis (SSPE) were given measles vaccination but had no history of natural measles. However, in the case who received measles vaccine, it has been extremely difficult to determine whether the actual cause of SSPE is the inoculated vaccine virus or not.

OBJECTIVES

To detect the measles virus genome in a patient with SSPE and to analyze its nucleotide and deduced amino acid sequence.

STUDY DESIGN

We applied the polymerase chain reaction (PCR) to detect the measles virus genome in specimens from a 12-year-old boy with SSPE who had received measles vaccine 10 years before and had no history of apparent natural measles. The oligonucleotide primers for PCR were prepared based on the nucleotide sequence of the F and NP genes of the measles virus Edmonston strain.

RESULTS

F and NP genes were detected in both the cerebrospinal fluid and peripheral blood lymphocytes. Nucleotide and deduced amino acid sequence analysis of the F gene showed that the patient's virus was different from that of the vaccine strain. Judging from these results, it was likely that the SSPE-associated strain in this case was derived from the wild-type rather than the vaccine strain.

CONCLUSIONS

PCR is a useful method to establish a definitive diagnosis of SSPE and to study the nature of the SSPE-associated virus.

Immunoglobulin gene rearrangement in T-cell-rich reactive pleural effusion of a patient with B-cell chronic lymphocytic leukemia

Pleural effusion in chronic lymphocytic leukemia (CLL) is a relatively rare phenomenon. We report a case of a pleural effusion associated with B-cell CLL but with predominantly reactive T lymphocytes in the effusion. A cell surface phenotype study showed that T lymphocytes predominated in the pleural effusion, although B lymphocytes were predominant in the peripheral blood. Genotypic analysis of the cells in the peripheral blood, bone marrow, lymph node, and pleural effusion showed the same rearrangement pattern of the immunoglobulin heavy chain genes consistent with a B-lymphocytic neoplasm (CLL). A pleural biopsy demonstrated diffuse infiltration of lymphoid cells. Most of the cells demonstrated T cell markers, although some cells revealed B cell markers by immunologic staining. These results suggested that the pleural involvement by B-CLL may have caused a reactive T-lymphocyte proliferation in the pleura and pleural effusion. To our knowledge, this is the first published case indicating that genotypic analysis of immunoglobulin heavy chain gene rearrangement may be useful in the diagnosis of a pleural effusion associated with B-cell CLL.

[Purification of EcoO44I restriction endonuclease in Escherichia coli O44 isolated from an affected human]

A restriction endonuclases (ENase) designated EcoO44I was purified without non specific nucleases from enteropathogenic Escherichia coli O44 Hiromi strain of affected human origin. The yield was 1, 100 units/g of wet cells. The EcoO44I ENase recognized and cleaved the specific sequence of 5'-GGTCTC-3' (1/5) as was the case with Eco31I or BsaI ENase. Because of the stability and high yield, EcoO44I would be useful for recombinant DNA technology after isolation of EcoO44-positive, avirulent mutant strains of E. coli O44 Hiromi.

Identification of Schizosaccharomyces pombe gene psk1+, encoding a novel putative serine/threonine protein kinase, whose mutation conferred resistance to phenylarsine oxide

We have identified a novel putative protein kinase-encoding gene from Schizosaccharomyces pombe (Sp), designated psk1+, by using a highly conserved amino acid (aa) sequence motif to design amplification of DNA fragments using PCR. The putative translation product of psk1+ contains 436 aa, with a molecular mass of 49,317 Da. A single psk1+ was identified by genomic Southern blot analysis, and the genomic mapping indicated that psk1+ was localized in Sp chromosome III. Growth of wild-type Sp cells was inhibited by 0.5 microM phenylarsine oxide, a protein tyrosine phosphatase inhibitor, but psk1- cells were relatively resistant to this drug.

Developmental dyspraxia and developmental coordination disorder

This article discusses the role developmental dyspraxia plays in developmental coordination disorder (DCD), based upon a review of literature on apraxia, developmental dyspraxia, and DCD. Apraxia and dyspraxia have often been equated with DCD. However, it is argued that apraxia and dyspraxia primarily refer to the problems of motor sequencing and selection, which not all children with DCD exhibit. The author proposes to distinguish developmental dyspraxia from DCD. Other issues discussed include the assessment, etiology, and treatment of developmental dyspraxia and DCD, and the relationship between DCD and learning disabilities. A research agenda is offered regarding future directions to overcome current limitation.

Correlation between immunophenotypic diversity and clinical features in B-cell lymphoblastic lymphoma

Lymphoblastic lymphoma (LBL) is a highly malignant subtype of non-Hodgkin's lymphoma (NHL) and generally carries a T-cell phenotype with mediastinum or central nervous system (CNS) involvement. However, only a small proportion of LBL exhibit a B-cell phenotype (B-LBL), and these frequently present at the head and neck without mediastinum or CNS involvement. Three immunological subgroups may exist. The most predominant CD10-positive pre-B-cell type, corresponding to a precursor B-cell neoplasm, frequently involves the head and neck. The second, CD10-negative or mature B-cell type, defined by the absence of CD10 or presence of surface membrane immunoglobulins combined with expression of CD19 or CD20, often involves the mediastinum. The final group is a CD5-positive B-cell type corresponding to a blastic variant of mantle cell lymphoma (MCL). Its clinical course is less aggressive, patients are often older, and nodal lesions are more frequent than extranodal involvement. Thus, B-LBL is immunologically diverse, but its biological behavior correlates with the immunophenotype.

Laparoscopic approaches in the management of patients with early gastric carcinomas

In eight Japanese patients, three different laparoscopic procedures were used to excise an early gastric carcinoma; partial resection in four, intragastric resection of the gastric mucosa in two, and laparoscopic-assisted distal partial gastrectomy with the abdominal wall-elevating method in two patients. Histological examinations revealed that the lesions were completely resected, and there was no evidence of lymphatic metastasis. The operation time ranged from 2 to 4 h. These forms of laparoscopic gastric surgery for patients with early gastric carcinomas may be useful from the standpoint of minimal access, rapid recovery, less pain, and good cosmesis.

Isoenzymes of cyclic nucleotide phosphodiesterase in the human aorta: characterization and the effects of E4021

In extracts of the human aorta, five isoenzymes of cyclic nucleotide phosphodiesterase, namely, phosphodiesterase I, phosphodiesterase II, phosphodiesterase III, phosphodiesterase IV and phosphodiesterase V, were identified exclusively in the cytosolic fraction, and no phosphodiesterase activity was detected in the particulate fraction. Phosphodiesterase V and phosphodiesterase I were the major cGMP-hydrolyzing enzymes in the human aorta. A novel vasorelaxant, sodium 1-[6-chloro-4-(3,4-methylenedioxybenzyl)aminoquinazolin-2-yl ]piperidine-4- carboxylate sesquihydrate (E4021), relaxed prostaglandin F2 alpha-precontracted strips of human pulmonary artery with an ED50 value of 0.5 microM. E4021 potently and highly selectively inhibited the activity of phosphodiesterase V from human aorta with a Ki value of 2.4 nM. These results suggest that there is a unique distribution of phosphodiesterase isoenzymes in the human aorta and that inhibitors of phosphodiesterase V might be useful as a new type of vasodilator in the treatment of clinical disorders.

Appendiceal intussusception due to an appendiceal malignant polyp--an association in a patient with Peutz-Jeghers syndrome: report of a case

A 40-year-old woman with Peutz-Jeghers syndrome and an appendiceal intussusception is reported. In this patient, the lead point was a large sessile, appendiceal polyp. The invaginated and inverted portion of the appendix resembled the long stalk of a pedunculated polyp on roentgenography and endoscopic examination. Histologically, the appendiceal polyp was a villous adenoma with mild to severe atypia and focal carcinoma in situ. In patients with Peutz-Jeghers syndrome, hamartomatous polyps and colorectal adenomatous polyps with highly malignant potential can coexist and must be managed appropriately. Therefore, when evaluating a polypoid or a pedunculated lesion in the cecal lumen, the possibility of an appendiceal intussusception should also be investigated.

Xenopus PKN: cloning and sequencing of the cDNA and identification of conserved domains

cDNA clone encoding Xenopus laevis PKN has been isolated from Xenopus kidney library. Sequencing of this clone has revealed a single open reading frame encoding a protein of 901 amino acids. Immunoprecipitate from cytoplasmic fraction of COS7 cells transfected with this cDNA construct using antiserum against bacterially expressed Xenopus PKN revealed arachidonic acid-dependent autophosphorylation activity. Comparison of the closely related sequences of human and rat PKN with a protein from evolutionarily distant Xenopus, revealed several highly invariant domains in the NH2-terminal regulatory regions, suggesting that they participate in binding interaction with arachidonic acid.

Detection of reverse transcriptase activity by enzyme-linked immunosorbent assay in human immunodeficiency virus type 1

An enzyme-linked immunosorbent assay (ELISA) using biotin-labelled oligo-dT primer and digoxigenin (Dig)-dUTP was designed to measure the reverse transcriptase (RT) activity of human immunodeficiency virus type 1 (HIV-1). The ELISA system involves the selective detection step of a newly synthesized cDNA by two specific bindings, biotin-streptavidin binding and alkaline phosphatase (AP)-conjugated anti-Dig-Dig binding, and the enzymatic amplification step to increase coloring generated by AP. This method was used to measure the activity of RT in the culture supernatants of peripheral leukocytes obtained from four anti-HIV-1-positive persons cocultivated with those from four anti-HIV-1-negative persons. RT activity was detected in all of four anti-HIV-1-positive culture supernatants but not in those cultivated with anti-HIV-1-negative supernatants alone. Thus, our improved ELISA for detection of HIV-1 appears to be sensitive enough and useful for routine laboratory work. This non-radioactive method will also be useful for detecting other retroviruses and for screening of RT inhibitors.

High amplification of the hst-1 gene correlates with haematogenous recurrence after curative resection of oesophageal carcinoma

Amplification of the hst-1 gene was examined in 82 patients with oesophageal carcinoma by dot blot hybridization to assess the potential of haematogenous recurrence after curative resection. Intensity of amplification was considered negative (one- to twofold increase) in 45 patients, low (three-sixfold increase) in 19 and high (greater than sevenfold) in 18. Haematogenous recurrence after curative resection was found in seven of eight patients with high amplification and was significantly higher in such patients than in those without amplification (P < 0.05). The finding that sevenfold or greater amplification of the hst-1 gene seems to be associated with haematogenous recurrence of oesophageal cancer after resection may serve to assess the clinical outcome.

Mantle cell lymphoma with the features of mucosa-associated lymphoid tissue (MALT) lymphoma in an HTLV-I-seropositive patient

A case of small lymphocytic B-cell lymphoma with seropositivity for human T-cell leukemia virus type I (HTLV-I), whose clinical features were closely related to those of mucosa-associated lymphoid tissue (MALT) lymphoma, is presented. The neoplastic cells of the lymph node were immunologically positive for CD5, in addition to several B-cell markers, but negative for CD10, and cytogenetically carried a t(11;14)(q13;q32). These findings were fully consistent with so-called mantle cell lymphoma (MCL). In addition to the lymph nodes and bone marrow, multiple extranodal sites including lacrimal and salivary glands, lung and stomach (where MALT is present) were occupied by lymphoma cells. These extranodal lesions were immunologically identical to the lymph nodes (CD5(+), CD10(-)), but histologically showed lymphoepithelial lesions (LEL) characteristic of MALT lymphoma. These findings suggest a possible relationship between MCL and MALT lymphoma, and the neoplastic cells are thought to originate from the CD5-positive B cells, which are present near the areas across the mantle and marginal zones. Furthermore, HTLV-I-infection, which appears to create an immunodeficient state or modulate the B-cell response, is thought to play a role in B-cell lymphomagenesis.

Laparoscopically assisted distal partial gastrectomy for early-stage gastric carcinomas

Endoscopic mucosal resection (EMR) is now in clinical use for the management of small, early-stage gastric, carcinomas, although some patients are treated via laparotomy when the lesions are not suitable for, EMR due to their size, depth, and location. In many cases of invasive mucosal carcinoma with submucosal involvement, the regional lymph nodes along with the distal portion of the stomach must also be resected. In order to remove the whole resected specimen, a mini-laparotomy of appropriate length (5 cm) is performed which can be located at the optical port site after removing the laparoscope. By applying an abdominal wall elevator through the mini-laparotomy, direct vision is possible which facilitates resection of the regional lymph nodes and intestinal anastomosis. We describe our technique for laparoscopically assisted distal gastrectomy and present our early clinical results.

Characterization of the myosin-binding subunit of smooth muscle myosin phosphatase

A myosin phosphatase was purified from chicken gizzard smooth muscle. The holoenzyme is a trimer and consists of 130,000-, 38,000-, and 20,000-Da subunits (in agreement with the results of Alessi et al.: Alessi, D., MacDougall, L. K., Sola, M. M., Ikebe, M., and Cohen, P. (1992) Eur. J. Biochem. 210, 1023-1035). The catalytic subunit, 38,000 Da, is the type 1 delta isoform, and its derived amino acid sequence is identical to the rat isoform. The larger subunit bound to myosin and also interacted with the catalytic subunit. cDNA clones encoding the large subunit were isolated from chicken gizzard cDNA libraries. Overlapping clones indicated the presence of two isoforms, and open reading frames of 2889 and 3012 bases were obtained. These encoded proteins of 963 and 1004 amino acids, with masses of 106,700 and 111,600 Da, respectively. The insert in the larger isoform is in the center of the molecule, at residues 512-552. The N-terminal third of the molecule is composed of eight repeat sequences, similar to the cdc10/SWI6 or ankyrin repeat. Myosin binding and binding to the catalytic subunit are properties of a 58,000-Da fragment that represents the N-terminal part of the molecule.

Activation of PKN, a novel 120-kDa protein kinase with leucine zipper-like sequences, by unsaturated fatty acids and by limited proteolysis

PKN, a novel protein kinase with catalytic domain homologous to PKC family and unique amino terminal leucine zipper-like sequences, was purified partially from COS7 cells transfected with the cDNA construct encoding human PKN for enzymatic characterization of the enzyme. Using serine containing synthetic peptides based on PKC pseudosubstrate sites as the phosphate acceptors, kinase activities estimated from partially purified PKN were not stimulated by Ca2+/phosphatidylserine/diolein but were activated several-fold to several tens-fold by 40 microM unsaturated fatty acids, such as arachidonic acid, linoleic acid, and oleic acid. Autophosphorylation of the immunoprecipitates using anti-PKN antiserum was also stimulated by various unsaturated fatty acids. Limited proteolysis of PKN with trypsin induced an enhancement of the peptide kinase activity that was almost independent of arachidonic acid.