N-Linked glycosylation is essential for the yellow head virus replication cycle

Yellow head virus (YHV) particles contain a nucleocapsid protein (p20) and two envelope glycoproteins (gp116 and gp64). The glycans attached to the two glycoproteins are N-linked and are complex and high mannose types, respectively. Here, we show that treatment with the N-linked glycosylation inhibitor tunicamycin in YHV-infected black tiger shrimp (Penaeus monodon) resulted in less severe yellow head disease and reduced mortality when compared with untreated control shrimp. Quantitative real-time reverse transcription PCR analysis also revealed lower YHV copy numbers in the haemolymph of treated than control shrimp. This was concurrent with less intense immuno-reactions in tissues of treated versus untreated shrimp using mAbs against all three YHV structural proteins. In addition, transmission electron microscopy of lymphoid organ tissue of the treated and untreated shrimp [eight collected at 36 h and eight at 48 h post-infection (p.i.)] revealed only unenveloped nucleocapsids in all but one of the treated shrimp (collected at 48 h p.i.). By contrast, all the untreated shrimp showed a mixture of many unenveloped and enveloped virions. These results were supported by purification of YHV from the cell-free haemolymph of treated and untreated shrimp followed by YHV structural protein analysis by SDS-PAGE. It revealed three expected structural protein bands (116, 64 and 20 kDa) from the untreated shrimp but no structural protein bands from the tunicamycin-treated shrimp (confirmed by Western blot analysis). Overall, the results indicated that blocking glycosylation with tunicamycin inhibited the formation of mature YHV virions and their subsequent release into shrimp haemolymph, reducing the severity of disease.

Changes in oviduct structure in the black tiger shrimp, Penaeus monodon, during ovarian maturation

OBJECTIVE

To examine the structure of the oviduct of the shrimp Penaeus monodon.

METHODS

The oviducts of P. monodon with three different major groups of ovarian development (Group (Gr.) 1: Stages I & V; Gr. 2: Stages II & III; and Gr. 3: Stage IV) were examined by light, transmission electron, and scanning electron microscopies, respectively.

RESULTS

The epithelium of the oviduct in Gr. 1 was composed of tall simple columnar cells with their basal nuclei located on the basement membrane and its thick collagen fibers. In Gr. 2, the oviduct seemed to produce some substances and their epithelial cells became transitional with centrally located nuclei and formed some vacuoles. Obviously, the epithelial cells in Gr. 3 (at Stage IV) were disorganized, disrupted, and shed accumulated spherical secretory substances including some cellular contents into the lumen.

CONCLUSIONS

The structural changes of the P. monodon oviduct were related to ovarian maturation stages (Grs. 1-3). Prior to spawning, only the oviduct epithelium at ovary Stage IV produced and secreted a number of spherical secretion substances into the lumen. These substances may act as the oviductal lubricants to facilitate the spawning process.

Visual detection of white spot syndrome virus using DNA-functionalized gold nanoparticles as probes combined with loop-mediated isothermal amplification

The integration of loop-mediated isothermal amplification (LAMP) and DNA-functionalized AuNPs as visual detection probes (LAMP-AuNPs) was developed and applied for the detection of white spot syndrome virus (WSSV) from Penaeid shrimp in this study. The principle of this combination assay relies on the basis of stability characteristics of the DNA-functionalized AuNPs upon hybridization with the complementary target DNA toward salt-induced aggregation. If the detected target DNA is not complementary to the ssDNA probes, the DNA-functionalized AuNPs will be aggregated due to the screening effect of salt, resulting in the change of solution color from red to blue/gray and shift of the surface plasmon peak to longer wavelength. While the DNA-functionalized AuNPs are perfectly matched to the detected target DNA, the color of solution still remains red in color and no surface plasmon spectral shift. This assay provides simply technique, time-saving and its detection results could be achieved qualitatively and quantitatively by visualization using the naked eye due to the colorimetric change and by measurement using the UV-vis spectroscopy due to the surface plasmon spectral shift, respectively. In this study, LAMP-AuNPs assay was successfully developed with the detection of WSSV-LAMP generated product at 0.03 μg/reaction, and showed the sensitivity of 2 × 10(2) copies WSSV plasmid DNA, that is comparable to the most sensitive method reported to date. The LAMP-AuNPs assay described in this study revealed a highly sensitive, rapid and reliable diagnostic protocol for detection of WSSV. This technique has a potential as a routine method for assessing the infectious diseases in Penaeid shrimp not only for WSSV, but also for other shrimp pathogens, and can be useful tool in field conditions for the diagnosis or surveillance programs.

A novel integrase-containing element may interact with Laem-Singh virus (LSNV) to cause slow growth in giant tiger shrimp

Background

From 2001-2003 monodon slow growth syndrome (MSGS) caused severe economic losses for Thai shrimp farmers who cultivated the native, giant tiger shrimp, and this led them to adopt exotic stocks of the domesticated whiteleg shrimp as the species of cultivation choice, despite the higher value of giant tiger shrimp. In 2008, newly discovered Laem-Singh virus (LSNV) was proposed as a necessary but insufficient cause of MSGS, and this stimulated the search for the additional component cause(s) of MSGS in the hope that discovery would lead to preventative measures that could revive cultivation of the higher value native shrimp species.

Results

Using a universal shotgun cloning protocol, a novel RNA, integrase-containing element (ICE) was found in giant tiger shrimp from MSGS ponds (GenBank accession number FJ498866). In situ hybridization probes and RT-PCR tests revealed that ICE and Laem-Singh virus (LSNV) occurred together in lymphoid organs (LO) of shrimp from MSGS ponds but not in shrimp from normal ponds. Tissue homogenates of shrimp from MSGS ponds yielded a fraction that gave positive RT-PCR reactions for both ICE and LSNV and showed viral-like particles by transmission electron microscopy (TEM). Bioassays of this fraction with juvenile giant tiger shrimp resulted in retarded growth with gross signs of MSGS, and in situ hybridization assays revealed ICE and LSNV together in LO, eyes and gills. Viral-like particles similar to those seen in tissue extracts from natural infections were also seen by TEM.

Conclusions

ICE and LSNV were found together only in shrimp from MSGS ponds and only in shrimp showing gross signs of MSGS after injection with a preparation containing ICE and LSNV. ICE was never found in the absence of LSNV although LSNV was sometimes found in normal shrimp in the absence of ICE. The results suggest that ICE and LSNV may act together as component causes of MSGS, but this cannot be proven conclusively without single and combined bioassays using purified preparations of both ICE and LSNV. Despite this ambiguity, it is recommended in the interim that ICE be added to the agents such as LSNV already listed for exclusion from domesticated stocks of the black tiger shrimp.

Impact of yellow head virus outbreaks in the whiteleg shrimp, Penaeus vannamei (Boone), in Thailand

Yellow head virus (YHV) is known as a major pathogen in the black tiger shrimp, Penaeus (Penaeus) monodon. It can also cause serious mortality in farmed whiteleg shrimp, Penaeus (Litopenaeus) vannamei. However, there is no published information on the economic and/or production impact of the disease in P. vannamei. Shrimp with gross signs of YHV disease (faded body colour and 60-70% mortality) were observed in 20 study farms rearing P. vannamei in the central part of Thailand from the end of 2007 through early 2008. The estimated economic loss for these farms according to the Thai Animal Aquaculture Association was approximately US$3 million. Detailed sequence analysis of RT-PCR amplicons from shrimp in all the study ponds revealed the presence of YHV Type 1b (YHV-1b) alone (characterized by a 162-bp deletion in the ORF3 region encoding the structural gene for gp116) and the absence of YHV Type 1a (YHV-1a), the original YHV type reported from Thailand. Despite the large 162-bp deletion (= 54 deduced amino acids) in the gp116 structural gene, histopathology of YHV-1b infections was identical to that of YHV-1a infections, and electron microscopy revealed that YHV-1b virions were morphologically indistinguishable from those previously reported for YHV-1a. In addition, an existing commercial RT-PCR detection kit and an immunochromatographic test strip for the detection of YHV were proven to have been valid tests for both YHV-1b and YHV-1a. The source of the virus for these outbreaks was unlikely to have been the post-larvae used to stock the ponds, as they were derived from domesticated specific pathogen-free stocks free of YHV. Thus, it is possible that they originated from an unknown, natural reservoir.

Parvo-like virus in the hepatopancreas of freshwater prawns Macrobrachium rosenbergii cultivated in Thailand

A survey of cultivated giant freshwater prawns Macrobrachium rosenbergii from Thailand revealed the presence of unusual spherical to ovoid inclusions in nuclei of hepatopancreas tubule epithelial cells. These began as small eosinophilic inclusions that became more basophilic as they increased in size. They were present in both R-cells and E-cells but were largest and deeply basophilic only in the E-cells. Confocal laser microscopy revealed that stained nucleic acid fluorescence from the inclusions was lost by treatment with DNase I specific for double- and single-stranded DNA and also lost or reduced by treatment with mungbean nuclease specific for single-stranded nucleic acids. Transmission electron microscopy (TEM) revealed that the inclusions contained tightly packed, unenveloped, viral-like particles of approximately 25 to 30 nm diameter, resembling those produced by shrimp parvoviruses. However, PCR, in situ hybridization and immunohistochemical tests for shrimp parvoviruses previously reported from Thailand were all negative. These results suggested that the inclusions contained a parvo-like virus, not previously reported from M. rosenbergii in Thailand.

Mosquito cells accommodate balanced, persistent co-infections with a densovirus and Dengue virus

To study persistent viral co-infections in arthropods, we first produced stable, persistently infected C6/36 mosquito cell cultures by serial passage of exponentially growing whole cells infected with either a densovirus (AalDNV) or Dengue virus (DEN-2). We then obtained stable, persistent co-infections by reciprocal super-challenge and similar passaging. Persistently infected cultures did not differ from naïve-cell cultures in growth rate and cell morphology. Nor did they differ in high production of both viruses with high infection rates for naïve C6/36 cells. Immunocytochemistry revealed that 99-100% of the cells were coinfected but that super-infection order had some effect on antigen distribution for the two viruses. Our results combined with existing field information and previously published experimental work suggest that the capacity to support stable, viral co-infections may be a general phenomenon for arthropod cells, and that they may be achieved easily and rapidly by serial passaging of whole cultured cells. Such persistent infections would facilitate studies on interactions between co-infecting viruses.

Unstable lysogeny and pseudolysogeny in Vibrio harveyi siphovirus-like phage 1

Exposure of Vibrio harveyi (strain VH1114) to V. harveyi siphovirus-like phage 1 (VHS1) resulted in the production of a low percentage of lysogenized clones of variable stability. These were retrieved most easily as small colonies within dot plaques. Analysis revealed that VHS1 prophage was most likely carried by VH1114 as an episome rather than integrated into the host chromosome. In the late exponential growth phase, lysogenized VH1114 continuously produced VHS1 but also gave rise to a large number of cured progeny. The absence of phage DNA in the cured progeny was confirmed by the absence of VHS1 DNA in Southern blot and PCR assays. Curiously, these very stable, cured subclones did not show the parental phenotype of clear plaques with VHS1 but instead showed turbid plaques, both in overlaid lawns and in dot plaque assays. This phenotypic difference from the original parental isolate suggested that transient lysogeny by VHS1 had resulted in a stable genetic change in the cured clones. Such clones may be called pseudolysogens (i.e., false lysogens), since they have undergone transient lysogeny and have retained some resistance to full lytic phage development, despite the loss of viable or detectable prophage.

Partial characterization of a novel bacteriophage of Vibrio harveyi isolated from shrimp culture ponds in Thailand

A bacteriophage was isolated together with Vibrio harveyi (VH) 1114 a from a black tiger shrimp-rearing pond in Thailand. By negative staining transmission electron microscopy (TEM), the phage had an icosahedral head (diameter 60-62 nm), a rigid, non-contractile tail (9-10 nm x 100-120 nm) without a collar or terminal fibers and a genome of double stranded DNA of approximately 80 kb as determined by analysis of restriction enzyme digestion fragments. Since these features would place it in the family Siphoviridae, it was tentatively named V. harveyi siphoviridae-like phage or VHS1. VHS1 could also infect two VH reference strains LMD 22.30 and LMD 80.33 (=ATCC 14126) but yielded smaller plaques than with VH1114. The phage tolerated temperatures as high as 60 degrees C for up to 2h and overnight exposure to a broad range of pH. VHS1 lysogens of VH1114 were unstable, contained unaltered VHS1 DNA, were immune to VHS1 lysis and spontaneously released VHS1 in liquid cultures. Approximately 20 kb of the genome has been sequenced and deposited at GenBank but it mostly showed no significant homology with existing sequences in the database.

Synthethic peptide used to develop antibodies for detection of polyhedrin from monodon baculovirus (MBV)

The use of previously published primers to amplify the monodon baculovirus (MBV) polyhedrin gene sequence by polymerase chain reaction (PCR) from post larvae (PL) of Thai Penaeus monodon resulted in failure. As a result, the putative polyhedrin protein of MBV was isolated from infected PL by homogenization, differential centrifugation and density gradient centrifugation with verification by transmission electron microscopy (TEM). By SDS-PAGE, a single major protein band at 58 kDa was obtained from the putative polyhedrin fraction and this corresponded to a previous report of the molecular weight of polyhedrin from MBV. When used for N-terminal sequence analysis, the putative polyhedrin protein yielded a sequence of 25 amino acids (M F D D S M M M E N M D D L S G D Q K M V L T L A) that did not correspond to the deduced amino acid sequence derived from a previous report of a putative MBV polyhedrin gene amplicon. Despite this, a synthetic peptide of our 25 amino acid sequence (25Pmbv) was conjugated with bovine serum albumin and used as an antigen for antiserum production in mice. Using immunohistochemistry with tissue sections of PL infected with MBV or other viruses, the mouse anti-25Pmbv antiserum showed strong immunoreactivity to occlusion bodies of MBV only. It also showed strong reactivity to the 58 kDa putative polyhedrin protein in Western blots. Altogether, the results suggest that the 58 kDa protein is Thai MBV polyhedrin and that a previously reported MBV polyhedrin gene sequence may represent another protein or polyhedrin from a different variety of MBV.

Multiple pathogens found in growth-retarded black tiger shrimp Penaeus monodon cultivated in Thailand

In 2001-2002 throughout Thailand, black tiger shrimp Penaeus monodon farmers reported very unusual retarded growth. We have called this problem monodon slow growth syndrome (MSGS). Based on decreased national production, estimated losses due to this phenomenon were in the range of 13 000 million baht (approximately 300 million US dollars) in 2002. Since rearing practices had not changed, it was considered possible that the MSGS problem may have arisen from a new or existing pathogen. To examine this possibility, cultivated shrimp were sampled from 32 commercial rearing ponds that reported abnormally slow growth from eastern, central and southern regions of Thailand. Shrimp were randomly sampled from each pond and grouped into normal and small shrimp. Normal shrimp were defined as those with body weights (BW) of 24 g or more while small shrimp were defined as those that weighed 16.8 g or less. Pleopods were used for detection of monodon baculovirus (MBV), heptopancreatic parvovirus (HPV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) using specific polymerase chain reaction (PCR) assays. In addition, some shrimp were processed for normal histopathology and transmission electron microscopy (TEM). Most of the shrimp specimens were infected by at least 1 of these viruses but many had dual or multiple infections. Prevalence of HPV and combined HPV/MBV infections in the small shrimp was significantly higher than in the normal shrimp. In addition to the viruses, a new microsporidian species, gregarines and bacteria were also observed but were not significantly associated with the MSGS problem. Some of the small shrimp gave negative results for all these pathogens by PCR and histology and no new and unique histopathology was recognized in any of the samples. The findings suggested that HPV infection was a contributing factor but not the overriding factor responsible for MSGS. It is possible that MSGS is caused by an unknown pathogen or by some other presently unknown, non-pathogenic factor.

Parvovirus B19 caused fetal death: a case report in Thailand

This was a case of an intrauterine parvoviral B19 infection resulting in hydrops fetalis and enlarged placenta. Histologically, the virus was found to be in nucleated red cells of the fetus which was confirmed by electron microscopy. Careful placental examination at the gross and microscopic levels yielded the correct diagnosis.

Mycetoma and phaeohyphomycosis caused by Phialophora parasitica in Thailand

Phaeohyphomycosis caused by Phialophora parasitica is rare and it has never been documented in Thailand. The first two Thai cases of phaeohyphomycosis caused by P. parasitica were recognized in early 1990 at Ramathibodi Hospital, Bangkok, Thailand. Both patients had underlying diseases. The fungus developed in abscesses with pigmented mycelium at the lower extremity. Cultures from pus and tissue biopsies were positive for dematiaceous fungi. Light microscopic features suggested P. parasitica and which was illustrated by both scanning and transmission electron microscope. The first case was treated with itraconazole with a satisfactory initial response. The second case was successfully treated by surgical removal of the entire lesion.

Characterization and PCR detection of hepatopancreatic parvovirus (HPV) from Penaeus monodon in Thailand

Hepatopancreatic parvovirus (HPV) causes disease in several species of penaeid shrimp. Heavy infections may result in poor growth and reduced production for shrimp farmers. From one southern Thai shrimp pond with a high prevalence of HPV infection, 790 shrimp were sampled randomly and the hepatopancreas (HP) removed. Most HP were preserved in liquid nitrogen. However, every 10th HP (79 total) was divided into 2 parts appropriately fixed for examination by transmission electron microscopy (TEM) and light microscopy. Based on light microscopy, the prevalence of HPV infection in the pond was approximately 30% and its presence was confirmed by TEM of parallel samples. The virus was subsequently purified from hepatopancreatic homogenates of the samples preserved in liquid nitrogen. Negative staining of the purified viral preparation revealed unenveloped, icosahedral viral particles 22 to 24 nm in diameter. Agarose gel electrophoresis of nucleic acid extracts revealed the presence of 2 fragments, one very intense (5.8 kb) and the other weak (4.2 kb). The larger fragment was degraded by DNase I and S1 nuclease, indicating single-stranded DNA (ssDNA) characteristic of the viral family Parvoviridae. The smaller fragment was degraded by DNase I but not by S1 nuclease, indicating that it comprised double-stranded DNA. A genomic DNA library of the 5.8 kb ssDNA was constructed in pUC18 and a clone containing a 659 bp fragment specific and sensitive for HPV was selected for sequencing. Based on this sequence, an HPV-specific primer set was designed to yield a 156 bp amplicon by polymerase chain reaction (PCR) amplification. The expected 156 bp amplicon was obtained only in the presence of HPV DNA template (at as little as 1 fg purified DNA) and not with nucleic acid templates extracted from healthy shrimp tissue or other shrimp pathogens. It is hoped that this PCR assay will be useful to shrimp aquaculturists for early detection and screening of shrimp larvae, parental broodstock or other possible carriers of HPV in the shrimp cultivation system.

Localization and characterization of inclusion bodies in recombinant Escherichia coli cells overproducing penicillin G acylase

Various concentrations of isopropyl beta-D-thiogalactopyranoside (IPTG) were used to induce production of the enzyme penicillin G acylase by recombinant Escherichia coli harboring plasmid pQEA11. The plasmid pQEA11 carries a wild-type pga gene, which is under the control of the tac promoter and lacIq. At low IPTG concentrations (0.025-0.1 mM), enzyme activity increased with increasing IPTG concentrations. At higher IPTG concentrations (0.2 and 0.5 mM), enzyme activity declined progressively. Examination of induced recombinant E. coli cells by transmission electron microscopy showed the presence of only periplasmic inclusion bodies at low IPTG concentrations (up to 0.1 mM) and both periplasmic and cytoplasmic inclusion bodies at high IPTG concentrations (0.2 mM and 0.5 mM). Results from sodium dodecyl sulfate/polyacrylamide gel electrophoresis and immunoblots of whole-cell proteins, membrane proteins and inclusion body proteins in these cells indicated that cytoplasmic inclusion bodies constituted an accumulation of preproenzyme (i.e., precursor polypeptide containing a signal peptide) and that periplasmic inclusion bodies constituted an accumulation of proenzyme (i.e., precursor polypeptide lacking a signal peptide).

In vivo and in vitro studies on the morphological change in the monkey epidermal Langerhans cells following exposure to dengue 2 (16681) virus

A direct comparison of skin Langerhans cell (LC) morphologic change following in vivo and in vitro exposure to dengue-2 (DEN-2) virus (16681) was performed in the monkey to investigate any differences in functional activity profiles. Time-lapse study of skin biopsy at the intradermal (id) virus injection sites, and thin skin sheets removed from the monkey with exposure to virus in culture medium, revealed a highly active migration of epidermal LCs in both sets of experimental specimens. The migration led to a relatively higher number of dendritic cells (DC) which appeared in active migrational profiles, in the superficial dermis. Moreover, obvious cytoplasmic structural changes, corresponding to their immunologic function, were observed in these superficial dermal DCs 2 hours after exposure. Despite their similar changes, early and late endosomes with degraded virus-like particles could be seen in the skin sheets owing to lagging in cellular physiological process in vitro, but none in the skin biopsies. Existence of these endosomes, which was extremely difficult to visualize in vivo, highlighted the mode of antigen processing by the endocytic pathway. The present study showed that the epidermal LC was a potent antigen-presenting cell for eliciting the success of id immunization and carried out the immunological activity in vivo or in vitro in the like manner, in respect to the physiological conditions.

Cytochemical and immunological phenotying of acute nonlymphoblastic leukemia in Thai patients

Using morphology and cytochemical reaction, we could subclassify-according to FAB classification, 51 of our 56 cases of acute nonlymphoblastic leukemia (ANLL) as M1-M5. Five cases were undifferentiated. Using the immunophenotypic method, we could subclassify 51 of these patients as M1-M4. In addition, 3 cases of undifferentiated leukemia by the prior method were each classified as M1, M3, and myelo-megakaryoblastic leukemia. Correlation of ANLL subtype classification according to each method was not good. However, combination of both methods, using immunophenotypic analysis as a supplement would better subclassify the disease. One of the remaining 2 cases of undifferentiated leukemia was also shown to be myelo-megakaryoblastic leukemia by a positive platelet peroxidase reaction by ultrastructural cytochemistry. Thus, combination of these 3 methods could diagnose and subclassify 55 of the 56 cases (98%) of our ANLL patients.

Langerhans cell density and serological changes following intradermal immunisation of mice with dengue 2 virus

After the introduction of the dengue-2 (16681) virus by intradermal (i.d.) injection into the footpads of mice, Langerhans cells (LCs) increased in numbers within 24 h at the site of injection and neutralising antibody developed. On comparing the i.d. and intramuscular (i.m.) routes, antibody was produced more rapidly and at higher levels when the virus was injected by the i.d. route. Subsequent re-challenge by the i.d. route produced an even more rapid serological response with all mice producing significant neutralising titres within 12 h. Numbers of ATPase-positive LCs varied with time. A significant sharp drop in LC densities in the early post-injection phase directly correlated with the increased numbers of dendritic cells in the superficial dermis and interfollicular sinuses of draining lymph nodes (LN). Immunofluorescence showed the presence of viral antigen in the footpad epidermis and draining LN within minutes or within 2 h of challenge, respectively.

Ultrastructural characteristics of liver fluke associated human cholangiocarcinoma cell lines

The ultrastructure of a cholangiocarcinoma cell line (HuCCA-l) originally established from an intrahepatic bile duct tumor of a patient seropositive for a liver fluke infection was studied by scanning (SEM) and transmission (TEM) electron miscroscopy. With the SEM, the surface of HuCCA-1 cells were found to be covered with microvilli. The size of these microvilli varied from cell to cell and they were irregularly distributed. The TEM clearly revealed the presence of cytokeratin filaments, an intracytoplasmic lumen, tight junctions at the apices and desmosomes at the lateral surfaces of neighboring cells, all of which are characteristics of adenocarcinoma cell origin. However, the tumor mass that developed in a nude mouse following subcutaneous injection of these cells was found to exhibit some morphological changes. Specifically, about 20-30% of the tumor cells, particularly those lining the base of the tumor tubules, exhibited electron dense tonofilaments typical of squamous cells. However, this alteration was reversible as the cell line (HuCCA-1Nu) derived from this nude mouse-passage did not exhibit any characteristics reminiscent of squamous cells. These observations are consistent with those occasionally found in human cases reported previously by other investigators. Altogether, the data showed that squamous transformation of adenocarcinoma cells can occur under appropriate conditions. It further showed that reversion to adenocarcinoma cells can occur when the microenvironment is changed.

Effect of aloe vera gel to healing of burn wound a clinical and histologic study

In a study of twenty-seven patients with partial thickness burn wound, they were treated with aloe vera gel compared with vaseline gauze. It revealed the aloe vera gel treated lesion healed faster than the vaseline gauze area. The average time of healing in the aloe gel area was 11.89 days and 18.19 days for the vaseline gauze treated wound. Statistical analysis by using t-test and the value of P < 0.002 was statistically significant. In histologic study, it showed early epithelialization in the treated aloe vera gel area. Only some minor adverse effects, such as discomfort and pain were encountered in the 27 cases. This study showed the effectiveness of aloe vera gel on a partial thickness burn wound, and it might be beneficial to do further trials on burn wounds.

Establishment and characterization of cell lines from liver fluke-associated cholangiocarcinoma induced in a hamster model

Cholangiocarcinoma (CCA) is a relatively rare tumor that occurs primarily in tropical countries and particularly in those with a high incidence of liver fluke infection. A hamster model for a liver fluke-associated CCA has been described previously. In the present study, hamster cholangiocarcinoma cell lines were established and characterized in order to obtain information regarding diagnostically useful tumor marker which could shed light for a future investigation for human cholangiocarcinoma. Two related cell lines, one from the original intrahepatic bile duct tumor and one from an allotransplanted tumor, were established. The established cell lines were found to have population doubling times of 31 and 26 hours respectively, and were maintained in Ham's F12 medium supplemented with 10% fetal bovine serum for over 80 passages. The cell monolayers were subjected to scanning and transmission electron microscopic study and found to have ultrastructural characteristics, including cytoplasmic lumens, consistent with those of adenocarcinoma cells of epithelial origin. An immunoperoxidase study using monoclonal antibodies (MAbs) specific for tumor antigens showed the cytoplasm and membrane of both cell lines to be positive. These antigens were also secreted in soluble form into the culture medium, judging from polyacrylamide gel electrophoresis in the presence of SDS and from immunoblot analyses. Different lines of evidence presented suggested that a 200 kDa glycoprotein produced and secreted by the tumor cell lines could be considered a cholangiocarcinoma-associated marker which has diagnostic potential.

Silicosis in ceramic-industry workers with particular reference to the diagnostic value of bronchoalveolar lavage

We could identify, via bronchoalveolar lavage, crystals in the lavage fluid and in the alveolar macrophages. Thus, BAL could be another method for diagnosing silicosis patients.

Ultrastructural changes in mouse dermal capillaries induced by cytochalasin E

Cytochalasin E increased the vascular permeability in the dermis of one-day-old mouse. It simultaneously induced edema and erythema as resulted from the leakage of plasma and red blood cells through the intercellular gaps of endothelial cells in both capillaries and venules. Meanwhile, there was a markedly decrease in plasma protein transport via pinocytotic vesicles.