Prediction and management of strangulated bowel obstruction: a multi-dimensional model analysis

BACKGROUND

Distinguishing strangulated bowel obstruction (StBO) from simple bowel obstruction (SiBO) still poses a challenge for emergency surgeons. We aimed to construct a predictive model that could distinctly discriminate StBO from SiBO based on the degree of bowel ischemia.

METHODS

The patients diagnosed with intestinal obstruction were enrolled and divided into SiBO group and StBO group. Binary logistic regression was applied to identify independent risk factors, and then predictive models based on radiological and multi-dimensional models were constructed. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were calculated to assess the accuracy of the predicted models. Via stratification analysis, we validated the multi-dimensional model in the prediction of transmural necrosis both in the training set and validation set.

RESULTS

Of the 281 patients with SBO, 45 (16.0%) were found to have StBO, while 236(84.0%) with SiBO. The AUC of the radiological model was 0.706 (95%CI, 0.617-0.795). In the multivariate analysis, seven risk factors including pain duration ≤ 3 days (OR = 3.775), rebound tenderness (OR = 5.201), low-to-absent bowel sounds (OR = 5.006), low levels of potassium (OR = 3.696) and sodium (OR = 3.753), high levels of BUN (OR = 4.349), high radiological score (OR = 11.264) were identified. The AUC of the multi-dimensional model was 0.857(95%CI, 0.793-0.920). In the stratification analysis, the proportion of patients with transmural necrosis was significantly greater in the high-risk group (24%) than in the medium-risk group (3%). No transmural necrosis was found in the low-risk group. The AUC of the validation set was 0.910 (95%CI, 0.843-0.976). None of patients in the low-risk and medium-risk score group suffered with StBO. However, all patients with bowel ischemia (12%) and necrosis (24%) were resorted into high-risk score group.

CONCLUSION

The novel multi-dimensional model offers a useful tool for predicting StBO. Clinical management could be performed according to the multivariate score.

Magnetic resonance imaging of cerebellar liponeurocytoma. A case report and review of the literature

Cerebellar liponeurocytoma is a rare benign neuroepithelial tumour. We describe the case of a 50-year-old man presenting with signs of increased intracranial pressure and cerebellar dysfunction. Magnetic resonance imaging showed a heterogeneous, well-circumscribed cerebellar mass with a predominant adipose content. Diffusion-weighted imaging showed an isointense mass with a hyperintense rim. Craniotomy demonstrated a soft grey mass with intratumoral bright patchy yellow areas. Histological and immunohistochemical findings indicated an advanced neuronal, glial and focal lipomatous differentiation with a low level of mitotic activity.

Inhibitors from natural products to HIV-1 reverse transcriptase, protease and integrase

Acquired immunodeficiency syndrome (AIDS), caused by human immunodeficiency virus type 1 (HIV-1) infection, is still one of the most challenging diseases of the early 21st century. Reverse transcriptase (RT), protease (PR) and integrase (IN) are three key enzymes of HIV-1. Despite the shortcomings of chemical drugs such as toxicity, lack of curative and multiple effects, the search for more and better anti-HIV agents has been focused on natural products. Many natural products have been shown to possess promising activities that could assist in the prevention and amelioration of the disease. Most of these natural anti-HIV agents have other medicinal values as well, which afford them further prospective as novel lead compounds for the development of new drugs. These natural products can deal with both the virus and the various disorders that are caused by HIV. In this review, natural inhibitors of RT, PR and IN have been found to be classified and the relationship between structure and inhibitory activity is discussed.

Behavioral study of calorie-restricted rats from early old age

PURPOSE

To investigate the effect of Calorie Restriction (CR) on learning and memory ability of early aged rats.

METHODS

18-month rats were subjected to restricted intake by 60% comparing with that of rats fed ad libitum (AL) for 6 months. We compared the overall health status, including survival rate and locomotor activity by open-field test. We examined the spatial cognition ability of the rats by Morris Water Maze.

RESULTS

Our results showed that CR rats had higher survival rate and spontaneous locomotor activity compared with AL rats. CR rats slowed the inability of spatial learning and reference memory.

CONCLUSION

These findings demonstrated that CR in early old rats delayed the declination of spatial cognition.

The requirements and mechanism for capsid assembly and budding of bovine foamy virus

Little is known about assembly of non-primate foamy virus (FV) such as bovine foamy virus (BFV). To help determine the requirements for assembly of BFV, we constructed BFV-Gag expression plasmids containing all or part of the gag gene, with or without modification by addition of myristate (Myr). Each construct was transfected alone, and with pFenv, into Sf-9 insect cells. The results showed that only the entire Gag could transit through nucleus, which is required for BFV viral assembly in the cytoplasm. Unlike other retroviruses (but like primate foamy viruses), BFV requires the coexpression of the Env protein for viral particle budding. In the case of BFV, this occurs at the plasma membrane rather than the endoplasmic reticulum (ER), due to lack of a functional ER retrieval signal (ERRS). The results also showed that addition of a Myr-membrane targeting signal to the C-terminus of Gag could restore the budding from plasma membrane, implying that Myr-membrane targeting signal could substitute for Env protein in budding.

[Construction of B. thuringiensis shuttle vector and expression of the cry1C gene]

We have constructed the E. coli-Bt shuttle vector pHV-1 by cloning the replicon (approximately 1.6 kb) of Bt ken-Ag and the aphI gene of pUC4K into pUC19. The rate of plasmid maintenance is more than 80% after 100 generations in E. coli, whereas 80% after 40 generations in Bti 4Q8. We have also constructed pHV-cry1C through cloning the alpha-amylase promoter from B. licheniformis and the cry1C gene from Bt 9510 into pHV-1 and introduced it into Bti 4Q8 by means of electroporation. Under the microscope, we can see that there is no crystal in Bti 4Q8, however, there are many rhomboid crystals in Bti 4Q8 (pHV-cry1C), which are smaller than those of Bt 9510. The bioassay result of Bti 4Q8 (pHV-cry1C) demonstrates that the expressed crystal protein is insecticidally active against Spodoptera exigue.

Expression of membrane-associated macrophage colony-stimulating factor (M-CSF) in Hodgkin's disease and other hematologic malignancies

We have identified a membrane-bound form of M-CSF (m-M-CSF) from an established human leukemic J6-1 cell line. To further understand its biological significance, we studied the expression of this membrane-associated growth factor in the lymph nodes of lymphoma patients and bone marrow smears from patients with hematologic diseases by immunohistochemical staining using anti-M-CSF MAb. We detected a high incidence of m-M-CSF expression in 75% (9/12) of the lymph node sections from patients with Hodgkin's Disease (HD). The antigens were detected primarily in large clusters of mononuclear Hodgkin's cells and the extracellular matrix (EM) surrounding them. In one HD patient with abundant multinucleated Reed-Sternberg (R-S) cells, all of them were intensely stained with anti-M-CSF MAb. In non-Hodgkin's lymphomas (NHL), the incidence (17.6 %) of m-M-CSF expression was lower (3/17). Yet, no m-M-CSF antigens were detected in the lymph nodes from six cases of non-hematologic malignancies and other diseases. A high response also was detected in bone marrow smears obtained from patients with hematologic malignancies, which include myeloid leukemias (32.5%), lymphomas with bone marrow metastasis (50%) and myelodysplastic syndromes (MDS) (37.5 %). By comparison, only 6.8 % of bone marrow smears from non-malignant hematologic diseases and 2.7% of lymphoid leukemias showed positive staining with anti-M-CSF MAb. Our results showed that high expression of m-M-CSF antigens is linked to some types of lymphomas, especially HD. and myeloid leukemias, and may play a role in the development of these hematologic malignancies.

[Effect of changes of amino acids of N-terminal region of the mature protein on secretion of alpha-amylase in B. subtilis]

The mutant plasmid pAmy413C, in which G takes the place of A at the 271 position of alpha-amylase gene on the pAmy413 from B. licheniformis, was constructed by site-direct mutagenesis. At the N-terminus of the mature alpha-amylase, amino acid +2Asn was substituted by +3Asp in the wild type protein. Then, the alpha-amylase output of the mutant plasmid pAmy413C in B. subtilis was 2.02-2.57 times higher than that of the wild type pAmy413C in the same strain. The amino acid sequencing at the N-terminus of the matural alpha-amylase revealsed that the recognition site of signal peptidase I moved one amino acid upstream, from Ala-(+2)Asn to AlaAla-(+3) Asp. That is, the +2Asn of the wild type was changed to the +3Asp of the mutant. The secondary structural analysis showed that a 14-cycle structure formed in the alpha-amylase mRNA when the free energy was -51.7 kcal. In this case, the mutant is identical with the wild type. The difference between them is that G at 271 position is no longer paired with U at 211 position, hence, a G-overhang is formed. The secondary structural analysis of protein showed that one amino acid diminished in the turn structure of amino acid at 33-37 position, and this very amino acid is involed in an alpha-helix structure. In short, all the changes mentioned above in conformation and charged amino acids contribute to the increase in the protein secretion in B. subtilis.

Enhancement of J6-1 human leukemic cell proliferation by cell-cell contact: role of an M-CSF-like membrane-associated growth factor MAF-J6-1

Density-dependent cell proliferation and cluster formation are growth phenotypes frequently associated with leukemia cells. The secretion of autocrine growth factor, such as granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 1 (IL-1), has been implicated as one possible mechanism in leukemogenesis. In many cases, however, leukemia cells do not appear to produce autocrine growth stimulators. J6-1 is an established human myeloid leukemia cell line that exhibits both density-dependent and cluster-forming growth characteristics. The effect of direct cell-cell contact on J6-1 cell proliferation was investigated. We have isolated from J6-1 cells a membrane-bound factor (designated as MAF-J6-1) that promoted the colony formation by both J6-1 cells and mouse bone marrow CFU-GM. The growth-promoting activity of MAF-J6-1 can be neutralized by either anti-macrophage-CSF (M-CSF or CSF-1) or anti-MAF-J6-1 monoclonal antibodies (MAb), suggesting that MAF-J6-1 is related to M-CSF. Using an immunoblot analysis with anti-MAF-J6-1 MAb, the MW of this membrane-associated factor was estimated to be 80 kDa. Both antibodies also induced a modest growth inhibition on J6-1 cells in vitro. Similarly, addition of exogenous recombinant human M-CSF augmented the colony formation by J6-1 cells, an effect also neutralized by both antibodies. Using an in situ hybridization technique, J6-1 cells were found to express a high level of c-fms proto-oncogene, which encodes the receptor for the M-CSF. Taken together, our results suggest that the membrane-bound MAF-J6-1 promote J6-1 cell proliferation and cluster formation through a 'juxtacrine' mechanism.

Identification and characterization of a human herpesvirus 6 gene segment that trans activates the human immunodeficiency virus type 1 promoter

Human herpesvirus 6 (HHV-6) is a lymphotropic herpesvirus, and in vitro, HHV-6 can productively infect many of the same cell types as can human immunodeficiency virus (HIV). Coinfection by both viruses in vitro can lead to both activation of the HIV promoter and acceleration of cytopathic effects. We have previously demonstrated that a large, 22.25-kb cloned HHV-6 fragment, pZVB70, can trans activate HIV promoter expression in vitro. In this study, we show that the pZVB70 fragment can trans activate the HIV promoter in human T-cell lines as well as in the monkey kidney cell line CV-1. The pZVB70 insert was digested with various restriction enzymes, and individual fragments were transfected into cells to test for their ability to trans activate the HIV promoter. By this method, we have identified a 1.8-kb subfragment, B701, that is involved in trans activation. Sequence analyses show that B701 potentially encodes a 143-amino-acid protein. This protein shares no homology with other herpesvirus proteins, such as ICP0 and ICP4, that have been shown to trans activate the HIV promoter. However, it shows weak sequence homology with the gene products encoded by the cytomegalovirus early US22 gene family, suggesting that the putative B701 protein may be an HHV-6 early regulatory protein. The 143-amino-acid coding sequence of B701 was cloned by polymerase chain reaction, and transfection of this construct into cells activated HIV promoter expression. The target site on the HIV promoter for the putative B701 protein is mapped to the NF-kappa B binding site. Our results suggest that the putative B701 protein may function by directly binding to the NF-kappa B site or may involve cellular factors, such as NF-kappa B, either directly or indirectly.