Vesicle-associated protein 1: a novel ovarian immunocontraceptive target in the common brushtail possum, Trichosurus vulpecula

Ovarian-based immunological research is currently restricted to proteins of the zona pellucida. This study examined the immunocontraceptive potential of a novel vesicle-associated protein, VAP1, previously isolated from the vesicle-rich hemisphere of the brushtail possum oocyte. Seven female possums were immunized against recombinant glutathione S-transferase-VAP1 fusion protein. Control animals (n=3) received antigen-free vaccinations. Following immunization, regular blood sampling determined the level and duration of immune response. Animals were monitored daily, pre- and post-immunization, to determine estrous cycling activity and the percentage of reproductive cycles yielding viable young. The reproductive tracts and somatic organs of VAP1-immunized (n=7), control-immunized (n=3) and non-immunized (n=5) animals were collected and examined by histology and transmission electron microscopy. VAP1 immunization caused a strong and sustained immune response. Elevated levels of VAP1 antibody binding were detected in sera following initial injections, and immune titers rose as boosters were administered. Immunization had no adverse effect upon animal behavior or body condition. Immunized females demonstrated no major change in annual estrous cycling activity; however, the percentage of reproductive cycles resulting in pouch young decreased significantly (P<0.05) by 40%. Histological and ultrastructural analyses revealed an abundance of lipid-like degradation bodies within the ooplasm of developing oocytes and the cytoplasm of failing uterine zygotes. Active macrophage invasion of enlarged endometrial glands was observed in the uteri of two females. Reproductive tract changes are discussed in relation to observed fertility decline. The results of this study indicate that VAP1 has exciting potential as an immunocontraceptive target for possum control in New Zealand.

In vitro assessment of antimicrobial activity of carvacrol, thymol and cinnamaldehyde towards Salmonella serotype Typhimurium DT104: effects of pig diets and emulsification in hydrocolloids

AIMS

To determine the effect of pig diets in vitro on the antimicrobial activity of carvacrol, thymol and cinnamaldehyde, and to identify an emulsifier/stabilizer that can stabilize the essential oil (EO) components in aqueous solution and retain their antimicrobial activity in the presence of the diets.

METHODS AND RESULTS

Emulsification of essential oil components with hydrocolloid solution was achieved by blending with a Polytron. Antimicrobial activity was measured through in vitro assays to determine the inhibition of bacterial growth by measuring the optical density at 600 nm or plating on nutrition agar after incubation of the mixtures of an EO component with the culture of Salmonella serotype Typhimurium DT104 in the presence or absence of pig diets. The results generated through the in vitro assays indicated that pig diets were able to abolish the antimicrobial activity of EOs. Xanthan, fenugreek and yellow mustard gums were the best in forming stable emulsions of five different EO components among ten different plant polysaccharides and surfactants examined. Emulsification of all the EO components in the fenugreek gum solution did not alter their antimicrobial activity. However, the antimicrobial activity of geraniol was significantly reduced when emulsified with other polysaccharides and surfactants. Both fenugreek and xanthan gum solutions were unable to protect the antimicrobial activity of carvacrol and thymol when mixed with the diets. Although cinnamaldehyde required no emulsification, but a high concentration (equivalent to at least three times of minimum bactericidal concentration for cinnamon oil) to inhibit Salmonella growth significantly in the presence of the diets, emulsification in fenugreek gum appeared to be essential for cinnamaldehyde solution to retain its antimicrobial activity during storage.

CONCLUSIONS

The diets for newly weaned pigs were a significant factor limiting the antimicrobial activity of EOs and their components. Cinnamaldehyde required a high concentration to retain its antimicrobial activity in the diets, in addition to its requirement for emulsification to stabilize its activity during the storage.

SIGNIFICANCE AND IMPACT OF THE STUDY

The assay with the diets used in this study for measuring the antimicrobial activity can be used in vitro for rapid and effective screening of potential antimicrobials for swine production. This study has identified polysaccharides that are able to stabilize EO component solutions. It has also identified cinnamaldehyde for further in vivo studies that may have potential in future application in controlling Salmonella and possibly other enteric pathogens in swine production.

MicroRNAs that underlie response to salvage chemotherapy in ovarian cancer

10542

Background: MicroRNAs (miRNAs) are non-protein coding, endogenous, small RNAs that can bind complementary mRNA to modulate gene expression and protein translation. Recent studies indicate that miRNAs may be mechanistically involved in ovarian cancer chemosensitivity and may play an important role in the development of chemoresistance. The objective of the current study was to explore the role of miRNAs in the response of platinum-resistant recurrent or persistent ovarian cancer to salvage chemotherapy. Methods: MicroRNA was extracted from 16 ovarian cancer cell lines. All samples were hybridized to a miRNA array that contained Ambion and Invitrogen probe sets. In parallel, the 16 ovarian cancer cell lines were treated with Doxorubicin, Topotecan, Paclitaxel, Docetaxel, and Gemcitabine, and their response to treatment evaluated using proliferation assays. Logistic regression analysis was used to identify miRNAs associated with responsiveness to individual chemotherapeutic agents. Results: Linear regression analysis identified a total of 39 miRNAs significantly associated with salvage chemotherapy responsiveness. Sixteen miRNAs were associated with response to Doxorubicin, 18 associated with response to Topotecan, 2 associated with response to Docetaxel, 9 associated with response to Paclitaxel, and 11 associated with response to Gemcitabine (p<0.05). Ten miRNAs were associated with more than one chemotherapy (miR-126, miR-199a, miR-202 [Doxorubicin, Topotecan, Gemcitabine], miR-26a, miR-320 [Doxorubicin, Topotecan], miR-181b [Doxorubicin, Topotecan, Paclitaxel], 181a [Topotecan, Gemcitabine, Adriamycin, Paclitaxel], miR-99b [Doxorubicin, Paclitaxel, Docetaxel], miR-31 [Docetaxel, Paclitaxel], miR-339 [Doxorubicin, Gemcitabine]). Conclusion: We have identified miRNAs that may influence ovarian cancer responsiveness to salvage chemotherapy. Ten of the miRNAs were associated with chemosensitivity to more than one drug. These miRNAs may regulate common determinants of chemoresistance and may also serve as novel therapeutic targets for patients with chemoresistant ovarian cancer. Further studies are warranted to validate these results.

No significant financial relationships to disclose.

Hepatic pre-sinusoidal vessels contract in anaphylactic hypotension in rabbits

AIM

The purpose of this study was to determine whether anaphylactic hypotension in rabbits is accompanied by hepatic venoconstriction, and the effects of anaphylaxis on hepatic segmental vascular resistances and liver weight in isolated perfused rabbit livers.

METHODS

The rabbits were sensitized by subcutaneous injection of antigen of 2.5 mg ovalbumin with complete Freund's adjuvant three times at 1 week interval. One week after sensitization, anaphylaxis was induced by an injection of 2.5 mg ovalbumin into the jugular vein of pentobarbital anaesthetized rabbits or the perfusate of rabbit livers perfused via the portal vein at a constant flow. Using the double occlusion technique to estimate the hepatic sinusoidal pressure, pre- (R(pre)) and post-sinusoidal (R(post)) resistances were calculated for the isolated perfused livers.

RESULTS

An antigen injection into the sensitized rabbits caused not only a decrease in systemic arterial pressure from 79 +/- 2 to 40 +/- 4 mmHg, but also an increase in portal venous pressure (P(pv)) from 9.5 +/- 2.2 to 24.1 +/- 3.9 cmH(2)O. Portal hypertension persisted for 8 min after the antigen injection. An injection of antigen into the perfusate caused a marked increase in P(pv) from 5.4 +/- 0.1 to 28.6 +/- 2.4 cmH(2)O at 6 min, but only a slight increase in double occlusion pressure from 2.2 +/- 0.2 to 3.8 +/- 0.2 cmH(2)O, resulting in a selective increase in R(pret) rather than R(post). Concomitant with the hepatic pre-sinusoidal constriction, liver weight loss occurred.

CONCLUSION

Anaphylactic hypotension in rabbits is accompanied by hepatic venoconstriction which is characterized by pre-sinusoidal contraction.

Islet-1 expression and its colocalization with luteinising hormone, thyroid-stimulating hormone and oestrogen receptor alpha in the developing pituitary gland of the sheep foetus

Islet-1 has been reported to be involved in pituitary development in the early stages of mouse embryogenesis. Oestrogen receptor (ER) and its expression may be involved in regulating pituitary development and its hormone-secreting function. Islet-1 expression and its correlations to ER in the developing pituitary gland are unknown. We therefore determined the pituitary cell specific expression of Islet-1 and its colocalization with ER alpha (ERalpha) in sheep foetus by immunohistochemistry. The results demonstrated that Islet-1-immunoreactive (ir) cells were distributed throughout the pituitary gland from day 60 of gestation until birth. The Islet-1-ir cell number was significant higher at day 90 and 120 of gestation compared to that at day 60 and at birth. All of the ERalpha-ir cells were colocalized with Islet-1 at day 60 of gestation, although a few ERalpha-ir cells were negative for Islet-1 in the later stage of gestation. The dominant cell type expressing Islet-1 is the gonadotroph, although small proportions of thyrotrophs and lactotrophs also express Islet-1. The proportion of luteinising hormone-ir gonadotrophs possessing Islet-1 kept rising from day 60 to day 120 of gestation and persisted until birth. The proportion of thyroid-stimulating hormone-ir cells expressing Islet-1 was at a high level from day 60-120 of the gestation and significantly declined at birth. The percentage of prolactin (PRL)-ir cells expressing Islet-1 was about 20% at day 60 of gestation. Very few PRL-ir cells contained Islet-1 in later stages of gestation. These data suggest that the development and functional establishment of pituitary gonadotrophs, thyrotrophs and lactotrophs might be regulated by the expressions of Islet-1 and ERalpha and by their interactions, although any mechanisms need to be elucidated further.

Role of interfacial effects in carbon nanotube/epoxy nanocomposite behavior

The interfacial effects are critical to understand the nanocomposite behavior based on polymer matrices. These effects are dependent upon the morphology of carbon nanotubes, the type of used polymer and the processing technique. Indeed, we show that the different parameters, as the eventual surfactant use, the ultrasonic treatment and shear mixing have to be carefully examined, in particular, for nanotube dispersion and their possible alignment. A series of multiwalled nanotubes (MWNT) have been mixed with a regular epoxy resin under a controlled way to prepare nanocomposites. The influence of nanotube content is examined through helium bulk density, glass transition temperature of the matrix and direct current electrical conductivity measurements. These results, including the value of the percolation threshold, are analyzed in relationship with the mesostructural organization of these nanotubes, which is observed by standard and conductive probe atomic force microscopy (AFM) measurements. The wrapping effect of the organic matrix along the nanotubes is evidenced and analyzed to get a better understanding of the final composite characteristics, in particular, for eventually reinforcing the matrix without covalent bonding.

Rapid sample preparation method for PCR-based detection of Escherichia coli O157:H7 in ground beef

AIM

To develop an improved, rapid and sensitive sample preparation method for PCR-based detection of Escherichia coli O157:H7 in ground beef.

METHODS AND RESULTS

Fresh ground beef samples were experimentally inoculated with varying concentrations of E. coli O157:H7. PCR inhibitors were removed and bacterial cells were concentrated by filtration and centrifugation, and lysed using enzymatic digestion and successive freeze/thaw cycles. DNA was purified and concentrated via phenol/chloroform extraction and the Shiga toxin 1 gene (stx1) was amplified using PCR to evaluate the sample preparation method. Without prior enrichment of cells in broth media, the detection limit was 103 CFU g-1 beef. When a 6 h enrichment step was incorporated, the detection limit was 1 CFU g-1 beef. The total time required from beginning to end of the procedure was 12 h.

CONCLUSIONS

The sample preparation method developed here enabled substantially improved sensitivity in the PCR-based detection of E. coli O157:H7 in ground beef, as compared to previous reports.

SIGNIFICANCE AND IMPACT OF THE STUDY

Superb sensitivity, coupled with quick turn-around time, relative ease of use and cost-effectiveness, makes this a useful method for detecting E. coli O157:H7 in ground beef.

Sexual development and the effects of active immunization against GnRH in Chinese Tanyang ram lambs

Tanyang is one of the most important sheep breeds in the northwest of China. However, there is no detailed data on sexual development and timing of puberty/sexual maturity of this breed. This experiment was designed to study the relationships between growth rate and sexual development by measuring body weight, testis diameter, and plasma testosterone concentrations, and observing sexual behavior through puberty from 3 to 8 months old of entire Tanyang ram lambs. At same time, to assess the potential efficacy and welfare benefits of non-surgical castration, the effect of active immunization against gonadotrophin-releasing hormone (GnRH) on sexual development and growth rate on ram lambs was evaluated, and compared with surgically castrated and entire lambs. The results showed that body weight increased at a constant rate from 3 to 8 months old of age. Testis diameter increased rapidly between 3 and 5 months, followed by a period of slow growth. Plasma testosterone concentrations increased sharply from 3 to 6 months of age (P<0.05), after which there were no significant changes from 6 to 8 months of age. Sexual behavior started from 5 months of age. After ram lambs were immunized against GnRH at 3 months of age, there was no increase in testis diameter in the first 4 months after immunization. Plasma testosterone concentrations remained at similar levels to surgically castrated lambs until 6 months of age, and the onset of sexual behavior was delayed, compared with entire ram lambs. GnRH immunization and surgical castration had no significant effect on the body weight by the end of this experiment. These results suggest that 4-5 months of age is a critical period for pubertal changes and testosterone plays an important role in the initiation of puberty and sexual maturity of Tanyang ram lambs in China. In addition, a single shot GnRH immunization at 3 months, acting as an alternative to surgical castration, is a practical method for Chinese Tanyang ram lambs, and provides animal welfare benefits.

Predicting toxicity of benzene derivatives by molecular hologram derived quantitative structure-activity relationships (QSARS)

Holographic quantitative structure-activity relationship (HQSAR) is an emerging QSAR technique with the combined application of molecular hologram, which encodes the frequency of occurrence of various molecular fragment types, and the subsequent partial least squares (PLS) regression analysis. Based on molecular hologram, alignment-free QSAR models could be rapidly and easily developed with highly statistical significance and predictive ability. In this paper, the toxicity data for a series of 83 benzene derivatives to the autotrophic Chlorella vulgaris (IGC50, negative logarithmic form of 6-h 50% population growth inhibition concentration in mmol/l) were subjected to HQSAR analysis and this resulted in a model with a high predictive ability. The robustness and predictive ability of the model were validated by "leave-one-out" (LOO) cross-validation procedure and an external testing set. The influence of fragment distinction parameters and fragment size on the quality of the HQSAR model have been also discussed.

[External irradiation combined with intracavitary brachytherapy for esophageal cancer]

OBJECTIVE

To study the long-term treatment results and acute irradiation response as well as complications following external irradiation combined with intracavitary brachytherapy.

METHODS

After loading intracavitary brachytherapy was used for patients with esophageal cancer. In 92 patients with esophageal cancer, 47 (group A) were treated with external irradiation only, and 45 (group B) with external irradiation and brachytherapy. The doses were 60.0 Gy - 70.0 Gy per 6-7 week for external irradiation, using 8 or 10 MV liner accelerator, and 5.0-8.0 Gy per fraction for intracavitary therapy.

RESULTS

There was a significant difference in acute response and complications as well as local recurrence rate between the two groups (P < 0.05). The survival rates of groups A and B at 1,3 and 5 years were 59.6%, 25.6%, 10.6% and 80.0%, 46.7%, 26.7% respectively (P < 0.05 respectively, using chi2 test). The complications related to intracavitary irradiation were esophageal perforation, esophagorrhagia, esophagotracheal fistula and esophageal narrowing. 66 patients died and 9 lost follow-up, giving a follow up rate of 90.2%.

CONCLUSION

External irradiation combined with afterloading intracavitary brachytherapy for esophageal cancer can reduce the local recurrence and enhance the long-term survival but with an increase of complications compared with the patients treated with external irradiation alone.

[Clinical study of juvenile-onset recurrent respiratory papillomatosis]

OBJECTIVE

To study the clinical behavior of juvenile-onset recurrent respiratory papillomatosis in order to find some factors correlated to the development of this disease, and to sum up the significance and experience of CO2 laser surgery.

METHOD

Sixty patients with juvenile-onset recurrent respiratory papillomatosis from September 1995 to December 1998 were retrospectively analyzed.

RESULTS

The age of onset in 50 cases (83.3%) was below 4 years, and the peak-age was 2 years. The rates of recurrence were 72.0% and 45.7% (chi 2 = 4.71, P < 0.05) below and over 2 years, respectively. The rates of aggressive disease were 88.0% and 54.3% (chi 2 = 7.66, P < 0.01) below and over 2 years, respectively. The predominant sites of the disease were the vocal cords, the false vocal cords, the laryngeal ventricle, the laryngeal surface of the epiglottis and the subglottic region. Tracheostomy induced the development of tracheal papilloma, therefore should be avoided as possible. Laryngeal papilloma might be divided into four types on the basis of the growth manner and surface form corresponding to clinical behaviors. Five patients were followed-up for 1.5 years without recurrence, 18 patients had fewer recurrences following treatment, 33 patients were under treatment, and 3 patients died. Nineteen patients lost follow-up. The major complications included laryngeal and tracheal stenosis.

CONCLUSION

Clinical behaviors of juvenile-onset recurrent respiratory papillomatosis were relevant to the age, growth form and tracheotomy. CO2 laser was an ideal instrument for ablation of the laryngeal papillomas with the following advantages: simple management, less bleeding, preservation of laryngeal structure and avoidance of tracheostomy.

Availability of glutamate and arginine during acid challenge determines cell density-dependent survival phenotype of Escherichia coli strains

The cell density-dependent acid sensitivity phenotypes of Escherichia coli strains K-12 and O157:H7 were examined with reference to three possible mechanisms of acid resistance. There was no evidence of any diffusible substance released from dead cells which could influence the cell density-dependent acid survival phenotype. Instead, cell density-dependent acid survival phenotype was associated with induction of glutamate- and arginine-decarboxylase acid survival pathways and concomitant availability of glutamate and arginine during acid challenge.

Structure, sequence and function of a marsupial LIF gene: conservation of IL-6 family cytokines

Leukaemia Inhibitory Factor (LIF) is a multifunctional cytokine with an obligate role in the mouse in embryonic implantation. In this paper we demonstrate the existence of a functional LIF gene in the marsupial Sminthopsis crassicaudata, and the presence of LIF-related sequences in the monotreme Tachyglossus aculeatus (Australian echidna). Isolation of genomic and cDNA clones from S. crassicaudata, indicated that the LIF gene is highly conserved between marsupials and monotremes in terms of sequence and genomic organisation. Critical functional residues within the LIF sequence were also conserved including residues implicated in intracellular LIF activity, and in interaction with the receptor subunits LIFR and gp130. These findings suggest that the structure and biochemical function of the protein is likely to be conserved. Consistent with this, purified recombinant S. crassicaudata LIF interacted functionally with mouse receptor components and was sufficient for maintenance of mouse embryonic stem (ES) cells in the undifferentiated state. Conservation of LIF outside eutherians is intriguing given the markedly divergent reproductive strategies which include, for some marsupial species, embryonic diapause, and in monotremes, the absence of implantation. The availability of marsupial LIF probes provides an opportunity to investigate conservation of expression and function in these mammals.

[Study on diarrhea disease and Escherichia coli strains harboring HPI pathogenicity island of Yersinia enterolitica in Shandong province]

OBJECTIVE

It was found that some E. coli strains previously identified as entero SLTs-producing and invasive E. coli (ESIEC), harboring HPI pathogenicity island of Yersinia enterolitica. This research was designed to reveal prevalence, susceptible group and clinical features it caused.

METHODS

All of the diarrhea patients were from the out-patient units of four hospitals in Shandong province from June to November of 1997. Stool specimen were collected before administration of antibiotics for isolation of enteric bacterial pathogen. Clinical symptoms were recorded at the same time.

RESULTS

A total number of 449 enteric pathogenic bacteria strains were detected among stool samples from 671 patients, with isolation rates of Shigella species and diarrheagenic E. coli 25.48% and 15.05% respectively. When irp-2 and ipaB gene fragments were used as DNA probes, 42 of 176 un-identifiable strains were found irp-2(+) and ipaB(-), which were identified as HPI-harboring E. coli. Typical symptoms of the diarrhea caused by HPI-harboring E. coli were described as mild, including abdominal pain, shiver and vapidity. Temperature of the patients was usually normal. Over 6 times of bowel movements per day was frequently observed, of which most were unformed stools with mucous.

CONCLUSION

HIP-harboring E. coli was an important diarrheagenic pathogen identified from 671 patients with diarrhea. Shigella was found to be the majority strain.

[Analysis of the polymorphisms of the AACT, ERAB and NACP genes in 15 patients with Alzheimer's disease]

OBJECTIVE

To analyze the polymorphisms of the AACT, ERAB and NACP genes in Han Chinese Alzheimer's disease (AD) patients.

METHODS

Denaturant gradient gel electrophoresis (DGGE) was used to scan all DNA fragments of 3 genes mentioned above in AD group (15 cases) and elderly control group (241 cases).

RESULTS

A25G and G39A substitutions were found in the AACT gene. The gene frequency of A25G was 80% in the AD group and 47% in the control group (P < 0.05). The gene frequency of G39A genotype was 13% in the AD group and 0.4% in the control group (P < 0.01). The allele (39) frequencies were also significantly different between the two groups (P < 0.01). We did not find any points with polymorphism in the ERAB and NACP genes.

CONCLUSION

A25G and G39A substitutions in the AACT gene are probably one of the risk factors to AD in Han Chinese.

[Expression of vascular endothelial growth factor in placenta from pregnancy complicated with pregnancy induced hypertension]

OBJECTIVE

To study the expression of vascular endothelial growth factor (VEGF) in placenta from normal pregnancy and pregnancy complicated with pregnancy induced hypertension (PIH) and the effect of VEGF on the etiology of PIH.

METHOD

Use the immunohistochemistry to determine the location and intensity of VEGF staining in placenta from 21 cases of normal pregnancy and 62 cases of mild, moderate and severe group of pregnancies complicated with PIH.

RESULT

Immunolocalization of VEGF in all cases was observed mainly in syncytiotrophoblast. Intensity of VEGF immunostaining in syncytiotrophoblast was significantly reduced in the moderate PIH group (P < 0.05) and the severe PIH group (P < 0.01) compared with both the mild PIH group and the normal group, while there was no qualitative differences between the mild PIH group and the normal group. Intensity of staining in decidual cells was also similar in all the groups.

CONCLUSION

These results suggest that VEGF is secreted mainly by syncytiotrophoblast in human placenta and the reduced VEGF may be responsible, at least in part, for the impaired vascular development in PIH.

Identification and characterization of a glomerular-specific promoter from the human nephrin gene

Podocytes are highly specialized cells that make up a major portion of the glomerular filtration barrier in the kidney. They are also believed to play a pivotal role in the progression of chronic renal disease due to diverse causes that include diabetes (3, 20, 24) and aging (1, 7). Despite the importance of podocytes for kidney function and disease, studies of this cell type have been hindered due to a lack of model systems. Recently, the gene responsible for congenital Finnish nephropathy was identified and named nephrin (13). Nephrin expression is restricted to slit diaphragms of podocytes (11, 30). Infants with congenital Finnish nephropathy develop massive proteinuria and subsequent kidney failure due to podocyte injury. We have identified a 1.25-kb DNA fragment from the human nephrin promoter and 5'-flanking region that is capable of directing podocyte-specific expression in transgenic mice; this represents the first glomerular-specific promoter to be identified. Use of this transgene will facilitate studies of the podocyte in vivo and allow the identification of transacting factors that are required for podocyte-specific expression.

High-pathogenicity island of Yersinia spp. in Escherichia coli strains isolated from diarrhea patients in China

The high-pathogenicity island (HPI) of Yersinia has been observed in 93% of 60 enteroadhesive Escherichia coli strains and 80% of E. coli strains isolated from blood samples. In the present study we investigated 671 fecal samples from patients with diarrhea in Shandong Province, China, and isolated HPI-harboring E. coli from 6. 26% of the samples. The isolation rates for patients with diarrhea in three age groups, 10 to 20, 30 to 40, and 50 to 60 years, were 6. 70, 12.35, and 10.81%, respectively. Therefore, HPI-harboring E. coli is the third most frequently isolated enteric pathogen from patients with diarrhea. Vomiting and abdominal pain were recorded for 33.33 and 66.67% of the patients, respectively. Stools with blood were observed for 9.52% of the patients. Twenty-four of 42 (57%) patients experienced a temperature over 37.4 degrees C. These observations indicate that HPI-harboring E. coli is one of the major causes of diarrheal disease in China and that the clinical symptoms caused by HPI-harboring E. coli differ from those caused by enteroadhesive E. coli.

Expression of estrogen receptors in the dorsal root ganglia of the chick embryo

Estrogen receptors (ER) are widely distributed in the central nervous system (CNS). Recent studies, to date in rat only, have shown that ER are also expressed in neurons of the dorsal root ganglia (DRG) where they appear to have functional roles. However, no data yet exists about estrogen receptors in the embryonic DRG. In the present study, immunocytochemical staining for ER in the DRG of chick embryos from day 6.5 to 18.5 (Hamburger and Hamilton St. 30-45) of incubation was performed. ER+ cells were first consistently observed at day 8.5 (St. 34), more concentrated in the ventral-lateral portion of the DRG. From day 8.5 to 12.5 (St. 38), the density of ER+ cells and the staining intensity increased, with no obvious changes from day (E) 12.5 to 18.5. Although ER is detected mainly in the cytoplasm of embryonic DRG neurones, ER+ cells with nuclear staining are sometimes observed and gradually increase in number during development. ER-immunoreactivity in the DRG at cervical, thoracic and lumbo-sacral levels is similar and no obvious differences in staining were observed between male and female embryos. ER+ neurons are also present in the sympathetic ganglia from E8.5 and some primary spinal motoneurons are ER+ beginning at E14.5. The results suggest that estrogen may play a role in the embryonic development of the DRG.

[Development of a peristaltic inhibition model in mice]

Diphenoxylate was administered to mice at the dose of 5 mg/kg BW for the development of peristaltic inhibition model for formulating the examination procedure of health foods. An ink solution containing 5% charcoal was then administered 30 minutes later. The length of ink progradation of the small intestine of mice was calculated 25 minutes after the administration of ink. The results in this model was stable and reliable, and it was recommended to use this model to verify the function of health foods.

Petrochemical exposure and menstrual disturbances

BACKGROUND

An exploratory, cross-sectional retrospective study was conducted to examine the effects of benzene exposure on menstrual problems.

METHODS

The study was based on a survey administered to over 3,000 women who worked in a large petrochemical company in Beijing, China. An abnormal menstrual cycle length (AMCL), defined as an average menstrual cycle length of greater than 35 days or less than 21 days, is the major outcome of interest.

RESULTS

After 7 years of benzene exposure, the adjusted odds ratio of having AMCL for each additional 5 years of exposure was 1.71 (95% CI 1.27-2.31). Feeling stressed at work was also an important predictor.

CONCLUSIONS

This study suggests a significant association of benzene exposure and perceived stress with menstrual disturbance. A prospective study is needed to confirm this finding.

[Clinical significance of beta-hCG and human placental lactogen in serum of normal pregnancies and patients with pregnancy induced hypertension]

OBJECTIVE

To examine the level of beta-hCG and Human Placental Lactogen (HPL) in maternal serum of normal pregnancies and patients with pregnancy induced hypertension (PIH) and to study the clinical significance and effects of them on the pathogenesis of the disease.

METHODS

Serum levels of beta-hCG and HPL of 142 normal pregnant women and 43 patients with PIH (16 mild, 12 moderate and 15 severe) were determined by radioimmunossay.

RESULTS

(1) Serum levels of beta-hCG in all PIH subgroups [(25.33 +/- 17.80) micrograms/L in mild, (33.12 +/- 4.91) micrograms/L in moderate, (42.19 +/- 17.47) micrograms/L in severe] were significantly higher than the normal pregnant group [(12.33 +/- 7.92) micrograms/L; P < 0.001]. There is positive correlation between levels of beta-hCG and degrees of PIH (r = 0.677, P < 0.05). (2) Serum levels of HPL in all PIH subgroups [(14.73 +/- 3.26) mg/L in mild, (11.44 +/- 4.02) mg/L in moderate, (12.73 +/- 4.18) mg/L in severe] did not show significant difference when compared with that of normal pregnant group [(12.78 +/- 4.67) mg/L; P > 0.05]. Furthermore, there was no correlation between levels of HPL and degrees of PIH (r = -0.300, P > 0.05).

CONCLUSIONS

Serum beta-hCG could reflect the degree of functional imbalance of the placental trophoblasts on PIH and it may be used as a clinical detecting index of PIH. On the other hand, HPL is not such a useful factor.

[Radial artery for coronary artery bypass grafting: operative techniques and early results]

OBJECTIVE

To review the experience coronary artery bypass grafting (CABG) with the radial artery (RA) performed from June 1997 to December 1999.

METHODS

A total of 71 patients received CABG in whom the performance of the radial and ulnar arteries were checked preoperatively with the modified Allen's test. A curvilinear skin incision was made from 3 cm distal to the cubital fossa to 2 cm before the proximal crease at the wrist. The RA was mobilized together with its satellite veins and surrounding fat tissues. Small branches were divided between titanium clips. Direct touching on the RA trunk was totally avoided and use of diathermy was minimized. A 1% papaverine solution of heparinized Ringer's was applied intraluminally into the free RA graft before it was stored in the same solution for later use. Seventy-two RAs were harvested and 79 distal anastomoses were made mostly to the posterior descending branches and the circumflex marginal branches. All the proximal anastomoses were directed to the aorta. Calcium channel blockers were routinely used for a period of 6 months postoperatively.

RESULTS

There was 1 death for an operative mortality of 1.4%. The death was not caused by failure of RA graft. There was no compartment syndrome or hand ischemia. No perioperative myocardial infarction was observed.

CONCLUSIONS

It is easy and safe to use the RA for CABG by which good results can be achieved. A'no-touch' harvesting technique and use of calcium-channel blockers are essential to the functioning of this conduit.

An association study of polymorphisms in the alpha-antichymotrypsin gene for Alzheimer disease in Han-Chinese

Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and DNA sequencing were employed to screen the coding region of the alpha-antichymotrypsin (AACT) gene in Han-Chinese population for polymorphism possibly associated with Alzheimer's disease (AD). Consequently, seven polymorphic sites including 25A>G, 39G>A, 370C>T, 662T>G, 892C>T, 923T>C and 1332A>G were detected. Of them, the 25A>G was reported previously and the others are all novel. We subsequently focused on the 25A>G and the 39G>A polymorphism that were of interest to us and conducted an association study of them by another scanning of 246 controls that matched the AD patients. Statistic test showed that both genotype (p=0.0378, Fisher's exact, two tailed) and allele frequency (p=0.0382, Fisher's exact, two tailed) of 39G>A are different between AD patients and the controls. As for 25A>G, lain only the heterozygous genotype A/G associates with AD (p=0.0220, chi(2)), but not the A allele frequency (p=0.1141, chi(2)).

Early markers of neuronal differentiation in DRG: islet-1 expression precedes that of Hu

The Hu and Islet-1 proteins are early markers of neuronal differentiation in the avian embryo. We here examine which of these markers is expressed first in avian dorsal root ganglia (DRG). Recently we showed that neural tube and DRG cells express Islet-1 after leaving the cell cycle, while sympathetic ganglion cells express Islet-1 while still dividing. Others have shown that Hu is found in cells that take up BrDU in the DRG, suggesting that it is expressed even earlier in the differentiation process than Islet-1. In this study we double-label sections for Hu and Islet-1 at several stages of embryonic development, using a simple antigen retrieval method in paraffin sections. At early stages many more cells are Islet-1(+) than Hu(+). In addition, although many cells express both markers, some Islet-1(+)/Hu(-) cells are observed but the converse is never found. At later stages, almost all DRG neurons express both markers, although a few Islet-1(+)/Hu(-) cells are still observed. Staining for Hu and Islet-1 at a later stage than previously reported shows that neither marker is expressed in DRG satellite cells. Our results suggest that Islet-1 is a useful marker for DRG neurons at earliest embryonic stages, and is likely to be expressed in DRG neurons before the Hu antigen.

Analysis of a mathematical model of the effect of inhibitors on the growth of tumors

In this paper, we study a model of tumor growth in the presence of inhibitors. The tumor is assumed to be spherically symmetric and its boundary is an unknown function r=R(t). Within the tumor the concentration of nutrient and the concentration of inhibitor (drug) satisfy a system of reaction-diffusion equations. The important parameters are Lambda(0) (which depends on the tumor's parameters when no inhibitors are present), gamma which depends only on the specific properties of the inhibitor, and beta; which is the (normalized) external concentration of the inhibitor. In this paper, we give precise conditions under which there exist one dormant tumor, two dormant tumors, or none. We then prove that in the first case, the dormant tumor is globally asymptotically stable, and in the second case, if the radii of the dormant tumors are denoted by R(s)(-),R(s)(+) with R(s)(-)<R(s)(+), then the smaller one is asymptotically stable, so that lim(t-->infinity)R(t)=R(s)(-), provided the initial radius R(0) is smaller than R(s)(+); if however R(0)R(s)(+) then the initial tumor in general grows unboundedly in time. The above analysis suggests an effective strategy for treatment of tumors.

[Detection of Escherichia coli strains harboring pathogenicity island of Yersinia enterolitica in diarrheal patients and animals in China]

OBJECTIVE

To investigate the prevalence of Escherichia coil strains harboring high pathogenicity island of Yersinia enterocolitica in diarrhea patients, animals, food samples and resulted clinical symptoms.

METHODS

Colony hybridization, DNA dot hybridization and polymerase chain reaction (PCR) were used.

RESULTS

HPI - harboring E. coli were found in the strains isolated in various provinces of China. The isolation rates were 27.05% (436/1,612) in the strains isolated from diarrhea patients, 10.23% (9/88) in the strains isolated from food samples and 5.71% (16/280) in the strains isolated from feces of cattle and pigs. Typical clinical symptoms of diarrhea caused by HPI - harboring E, coli were inappetency, abdominal pain, shiver and vapidity. Patient's temperature was usually normal or low. Over six episodes of diarrhea was frequently observed, of which most were unformed stools with mucous.

CONCLUSION

E. coli strains harboring high - pathogenicity - island of Yersinia species were frequently isolated from diarrhea patients, animals and food samples as well, which might be one of the major causes of diarrhea in China.

[Effect of irradiation on the shelf-life of aquatic products]

The effect of irradiation at doses of 0-10 kGy on the shelf-life of aquatic products was determined. The results showed that irradiation could not prolong the shelf-life of aquatic products kept at 25 degrees C. While the aquatic products were kept at refrigerator (4 degrees C), the irradiation could prolong the shelf-life and effectively reduce the total aerobic plate count. Irradiation could effectively reduce the number of coliform to less than 300/kg and eliminate Shigella shigae, Salmonella and Vibrio parahaemolyticus inoculated on shrimp, needle fish and crucian. A dose of 2.5 kGy could delay the rising of total volatile basal nitrogen in samples.

cDNA cloning, characterization, expression and recombinant protein production of leukemia inhibitory factor (LIF) from the marsupial, the brushtail possum (Trichosurus vulpecula)

A reverse transcription technique using RNA templates combined with polymerase chain reaction (RT-PCR) was used to clone the cDNA fragment encoding the amino acid sequence of mature LIF protein of the marsupial, the brushtail possum, Trichosurus vulpecula. A PCR product with expected size, of 546bp, and termed tvLIF, was obtained using cDNA reverse-transcribed from total RNA isolated from possum uterus. A genomic DNA fragment (about 650bp) between the specified primers was also amplified, indicating the similarity in structure and organization of this gene and LIF genes from studied eutherian species, although the full-length of its cDNA and genomic DNA needs to be further clarified. The deduced amino acid sequence of tvLIF shows a high level of sequence identity and similar molecular characteristics to eutherian LIF, which suggests similar biological actions of this molecule in this marsupial. Because the expression of LIF gene in other mammalian species has been found to be at very low levels and its transcripts cannot be detected by Northern hybridization analysis, the expression pattern of tvLIF in adult tissues and reproductive tracts during early development was investigated using the RT-PCR technique. Resultant products of the RT-PCR were further analyzed by Southern hybridization using tvLIF as a probe. tvLIF transcripts were detected in most of the adult tissues and in the reproductive tracts of pregnant females. These results lend support to the idea that LIF contributes to the maintenance of pregnancy in this marsupial.

The basic-helix-loop-helix protein pod1 is critically important for kidney and lung organogenesis

Epithelial-mesenchymal interactions are required for the development of all solid organs but few molecular mechanisms that underlie these interactions have been identified. Pod1 is a basic-helix-loop-helix (bHLH) transcription factor that is highly expressed in the mesenchyme of developing organs that include the lung, kidney, gut and heart and in glomerular visceral epithelial cells (podocytes). To determine the function of Pod1 in vivo, we have generated a lacZ-expressing null Pod1 allele. Null mutant mice are born but die in the perinatal period with severely hypoplastic lungs and kidneys that lack alveoli and mature glomeruli. Although Pod1 is exclusively expressed in the mesenchyme and podocytes, major defects are observed in the adjacent epithelia and include abnormalities in epithelial differentiation and branching morphogenesis. Pod1 therefore appears to be essential for regulating properties of the mesenchyme that are critically important for lung and kidney morphogenesis. Defects specific to later specialized cell types where Pod1 is expressed, such as the podocytes, were also observed, suggesting that this transcription factor may play multiple roles in kidney morphogenesis.

The use of laser scanning cytometry to assess depth of penetration of adenovirus p53 gene therapy in human xenograft biopsies

SCH58500 is an agent for gene therapy of cancer, consisting of a replication-deficient type 5 adenovirus (Ad5) expressing the human p53 tumor suppressor gene (Ad5/p53). An important question about the use of Ad5/p53 gene therapy is how to achieve the therapeutically effective delivery of an Ad5/p53 vector to the tumor. We wanted to determine the effective depth of penetration of an Ad5/p53 vector by dosing the vector in an experimental human xenograft/SCID model. To assess depth of penetration, we developed a novel methodology for scanning tissue sections by laser scanning cytometry (LSC). SCID mice were given intraperitoneal injections of either p53(null) SK-OV-3 human ovarian tumor cells or p53(mut) DU-145 human prostate tumor cells to establish xenograft solid tumors. Mice were then dosed once or twice at 24-hour intervals by intraperitoneal injection with SCH58500 (Ad5/p53), an adenovirus construct expressing beta-galactosidase (Ad5/beta-gal), or a buffer control. Additional groups of mice received a single intraperitoneal dose of 10 mg/kg paclitaxel either alone or coadministered with Ad5/p53. Twenty-four hours after each last dose, the human solid tumor xenograft and relevant mouse tissue were removed from each mouse for the analysis of Ad5/p53 penetration. Immunohistochemistry (IHC) for beta-galactosidase protein revealed a depth of penetration of between 1 and 10 cells from the tumor surface. In some mice, hepatocytes in the periportal regions of liver lobules were also positive, indicating systemic absorption of adenovirus from the peritoneal cavity. IHC staining for p53 and p21 proteins in SK-OV-3 solid tumor xenografts revealed similar Ad/p53 penetration. LSC was used to map and quantitate apoptosis in both tumor and liver tissue biopsies, with over 450,000 nuclei from liver tissue and 150,000 nuclei from tumor tissue being evaluated. LSC analysis demonstrated a high level of apoptosis in the tumors that had been removed from Ad5/p53-dosed mice (12.7-19.7%). This level of apoptosis was significantly higher (P < 0.05) than was observed for liver tissues taken from Ad5/p53-dosed mice (2.7-8.0%) or tumor tissues taken from either Ad5/beta-gal-dosed mice (3.0-6.4%) or buffer control-dosed mice (3.0-5.3%). Scan bit maps from the extensive LSC analyses confirmed that apoptosis was present to about the same depth (1-10 cells) as had been identified by IHC for beta-galactosidase, p53, and p21 proteins. Paclitaxel coadministered with Ad5/p53 had no effect on Ad5 penetration into solid tumors in vivo as measured by IHC for p53 or p21 protein. However, the combination therapy did cause an elevation in the number of tumor cells undergoing apoptosis.

[A case-control study on Guillain-Barre syndrome in children of North China]

OBJECTIVE

This study aimed at exploring the risk factors for Guillain-Barre syndrome (GBS).

METHODS

A case-control study design was used with 51 cases of GBS, diagnosed based on their symptoms, signs and electrophysiological examinations and exclusion of poliomyelitis and other acute flaccid paralysis, and 51 controls matched on age, sex and resident village. Serum IgG antibodies specific for Campylobacter jejuni were determined for all the subjects by enzyme-linked immunosorbent assay (ELISA) with a preparation of surface antigen of C. jejuni C(1) strain isolated from the patients and prevalent in north China. Each case and control were interviewed with his/her parents or guardians by a trained interviewer using an ad hoc questionnaire, including his/her demographic information, socioeconomic status, onset of the illness, and potential risk factors in their environment and personal hygiene. Data were analyzed with SAS software release 6.04 in a microcomputer.

RESULTS

GBS was associated with a few factors, such as residential areas (45 of the 51 cases living in the rural areas, accounting for 88.2% of the total), polio and hepatitis B vaccine immunization before onset of the illness (with ORs of 7.27 and 3.14, respectively), no hand washing after defecation and before meals (with an OR of 6.15) and getting cold and going to the river or lake site before onset of the illness (with ORs of 13.75 and 12.20, respectively). Infection with Campylobacter jejuni associated strongly with the illness (with an OR of 9.5, P < 0.001). Thirty-five of the 51 cases had precursor symptoms before onset of the illness (68.6%).

CONCLUSION

It suggests that occurrence of GBS may correlate to infection with Campylobacter jejuni and poor personal hygiene in children.

The presence of a heterotrimeric G protein and its role in signal transduction of extracellular calmodulin in pollen germination and tube growth

The role of heterotrimeric G proteins in pollen germination, tube growth, and signal transduction of extracellular calmodulin (CaM) was examined in lily pollen. Two kinds of antibodies raised against animal Gzalpha, one against an internal sequence and the other against its N terminus, cross-reacted with the same 41-kD protein from lily pollen plasma membrane. This 41-kD protein was also specifically ADP ribosylated by pertussis toxin. Microinjection of the membrane-impermeable G protein agonist GTP-gamma-S into a pollen tube increased its growth rate, whereas microinjection of the membrane-impermeable G protein antagonist GDP-beta-S and the anti-Galpha antibody decreased pollen tube growth. The membrane-permeable G protein agonist cholera toxin stimulated pollen germination and tube growth. Anti-CaM antiserum inhibited pollen germination and tube growth, and this inhibitory effect was completely reversed by cholera toxin. The membrane-permeable heterotrimeric G protein antagonist pertussis toxin completely stopped pollen germination and tube growth. Purified CaM, when added directly to the medium of plasma membrane vesicles, significantly activated GTPase activity in plasma membrane vesicles, and this increase in GTPase activity was completely inhibited by pertussis toxin and the nonhydrolyzable GTP analogs GTP-gamma-S and guanylyl-5'-imidodiphosphate. The GTPase activity in plasma membrane vesicles was also stimulated by cholera toxin. These data suggest that heterotrimeric G proteins may be present in the pollen system where they may be involved in the signal transduction of extracellular CaM and in pollen germination and tube growth.

The intrinsic factor-vitamin B12 receptor, cubilin, is a high-affinity apolipoprotein A-I receptor facilitating endocytosis of high-density lipoprotein

Cubilin is the intestinal receptor for the endocytosis of intrinsic factor-vitamin B12. However, several lines of evidence, including a high expression in kidney and yolk sac, indicate it may have additional functions. We isolated apolipoprotein A-I (apoA-I), the main protein of high-density lipoprotein (HDL), using cubilin affinity chromatography. Surface plasmon resonance analysis demonstrated a high-affinity binding of apoA-I and HDL to cubilin, and cubilin-expressing yolk sac cells showed efficient 125I-HDL endocytosis that could be inhibited by IgG antibodies against apoA-I and cubilin. The physiological relevance of the cubilin-apoA-I interaction was further emphasized by urinary apoA-I loss in some known cases of functional cubilin deficiency. Therefore, cubilin is a receptor in epithelial apoA-I/HDL metabolism.

Evaluation of new monoclonal anti-MyoD1 and anti-myogenin antibodies for the diagnosis of rhabdomyosarcoma

New monoclonal anti-MyoD1 and anti-myogenin antibodies were evaluated immunohistochemically to determine whether they are useful in discriminating rhabdomyosarcoma (RMS) from other soft tissue tumors in routinely processed sections. Neither MyoD1 nor myogenin was expressed in normal, mature striated muscle. In RMS, nuclear expression of MyoD1 and myogenin was found in 82 and 80% of non-overlapping cases, respectively. MyoD1 was generally expressed in small, primitive tumor cells, and larger cells exhibiting morphological evidence of skeletal muscle differentiation failed to express positive nuclear immunostaining. Positive nuclear staining for myogenin was stronger than that for MyoD1 in cases with abundant differentiated tumor cells, but was less prominent in cases in which small, primitive tumor cells predominated. No leiomyosarcomas, Ewing's sarcomas/peripheral primitive neuroectodermal tumors or other soft tissue tumors exhibited nuclear expression of MyoD1 or myogenin. In conclusion, both anti-MyoD1 and anti-myogenin antibodies are useful for diagnosing RMS and for discriminating RMS from other soft tissue tumors.

[Influence of icariin on cell membrane of highly metastatic human lung tumor cell line]

In this study, flow cytometry (FCM) and fluorescent probe technique were used to explore the influence of icariin (ICA) on cell membrane of PG. The data suggested that ICA could inhance membrane fluidity of PG and increase the expression of membrane HLA-ABC antigen. This could be one of the anticancer mechanisms of ICA.

Comparison of flow cytometry and laser scanning cytometry for the intracellular evaluation of adenoviral infectivity and p53 protein expression in gene therapy

The determination of recombinant adenoviral (rAd) infectivity and p53 protein expression is important for the evaluation of rAd vectors containing the p53 gene (rAd-CMV-p53) for gene therapy. We have previously reported that rAd5-CMV-p53 vectors can be assessed for infectivity and concomitant p53 protein expression in single- and two-color assays using intracellular staining methodology and flow cytometric analysis. We have compared the flow cytometry-based assays for rAd infectivity (hexon protein) and p53 protein expression with the new slide-based laser scanning cytometry (LSC). We report that LSC analysis of rAd-CMV-p53-infected human 293 cells correlated very well with flow cytometric analysis across a wide range of viral infectivity for both infectivity assessment (r2 = 0.97) and p53 protein expression (r2 = 0.96). Absolute values for infective titer and p53 protein expression titer from an rAd5-CMV-p53 production batch were similar and within experimental error with the two different analytical methods. Finally, bivariate format analysis of rAd-CMV-p53-infected cells revealed comparable results between LSC and flow cytometric analysis. LSC is a reliable and useful tool for the intracellular staining for adenoviral hexon protein expression for determining infectivity and for p53 protein expression from an expressed p53 transgene.

Papillary adenocarcinoma arising in placentoid bullous lesion of the lung: report of a case with immunohistochemical study

We report the case of a 52-year-old man with papillary adenocarcinoma arising in placentoid bullous lesion of the lung, which is a rare cystic lung disease. Macroscopically, the cyst contained a soft villous tumor closely resembling the placental chorionic villi of early gestation. Histologic examination revealed the tumor to be papillary adenocarcinoma with an abundant stromal core, which comprised vascular and lymphatic vessels, lymphocytes, fat cells, and smooth muscle. Immunohistochemically, adenocarcinoma cells were positive for CAM 5.2, epithelial membrane antigen, and PE10 (antisurfactant apoprotein A antibody). These results indicate that the adenocarcinoma was derived from the component epithelial cells of the cyst. Based on the tumor's macroscopic and microscopic appearance and on the results of the immunohistochemical studies, we conclude that the cystic tumor in our case arose in a placentoid bullous lesion of the lung.

[Effects of Curcuma phaeocaulis on learning and memory and lipid peroxide in mice]

Nine months mice were inoculated and the method of water maze test and lipid peroxide determination to study the effects of extract of Curcuma phaeocaulis Valeton on learning and memory ability and retarding of senescence. Results showed that in water maze test the time for the group with Curcuma phaeocaulis Valeton needed from initial position to the end was significantly shortened compared with old control. The error numbers for the group of Curcuma phaeocaulis Valeton were significantly decreased compared with old control after starting experiment for 18 days and 24 days and for 35 days no significance difference was showed between groups. The levels of brain, liver and red blood cells lipid peroxide in the group with Curcuma phaeocaulis Valeton were considerably lower than old control, hemoglobin content was considerably increased than old control.

Ultrastructure of the vacuolar apparatus in the renal proximal tubule microinfused in vivo with the cytological stain light green

To obtain insight into the basic mechanisms controlling endocytosis, we tested the effects of different perfusates containing the cytological stain light green on endocytosis and ultrastructure of the vacuolar apparatus in renal proximal tubule cells. Rat proximal tubules were microinfused in vivo for 2 min in the presence or absence of light green with the following solutions: (A) perfusates containing inorganic salts and (B) perfusates with organic components or protein. In other experiments, the tubules were first microinfused for 2 min with 0.9% NaCl in the presence or absence of light green, then 15 min later further microinfused with or without light green using either group A or B solutions in order to either aggravate or reverse possible changes. All infused tubules were fixed after 5 min with 1% glutaraldehyde and examined by electron microscopy. In tubules microinfused without light green, the endocytic vacuolar apparatus in the apical cytoplasm showed a normal ultrastructure. However, microinfusion of solutions containing light green in either inorganic salts or a low concentration of protein caused significant changes in the apical endocytic apparatus. Large endocytic vacuoles were absent, and invaginations and small endocytic vacuoles were decreased in frequency. On the other hand, the amount of dense apical tubules was significantly increased, and in some cells dense apical tubules had transformed into a cisternalike network. These changes were aggravated in tubules which received a second microinfusion of NaCl and reversed in tubules that received a second infusion of protein. Furthermore, in the tubules microinfused with light green using perfusates containing organic components or protein, the apical cytoplasm of proximal tubule cells showed an essentially normal endocytic apparatus. The present study demonstrates that microinfusion of renal proximal tubules with light green disrupted normal endocytic membrane trafficking and recycling. These changes could be prevented or reversed by microinfusion of solutions containing protein or organic components.

[Experimental study on effect of altitude xishi capsule in treating oleic acid induced lung injury in acute hypoxia rats]

OBJECTIVE

To explore the effect and pathophysiological mechanism of Altitude Xishi Capsule (XSC) on lung injury during acute hypoxia.

METHODS

A new model of acute lung injury was established by administering oleic acid into superior vena cava in experimental rat during acute hypoxia, which was formed by putting the animal in a hypobaric room, and reduced the pressure gradually in uniform speed till a simulated environment of 6000 m above sea level was formed and lasted for 12 hours. XSC was given orally to the rat before oleic acid administration. The effect of XSC on the model was observed by determination of PaO2, wet/dry ratio of lung and pathologic examination at 1, 2, 3 and 4 hours separately.

RESULTS

The respiratory frequency of model animal increased markedly, with the water content of lung reduced and aggravated as the hypoxia prolonged. XSC could obviously improve the pulmonary edema and inflammatory cell infiltration in lung.

CONCLUSIONS

The aforesaid acute lung injury model with successful rate of 100%, it resembles the clinical acute lung injury and was useful for research on pathophysiology and treatment of ARDS or acute lung injury, XSC could improve the oleic acid induced lung injury in hypoxia rats by reducing the pulmonary edema and inflammatory cell infiltration.

[Myocardial ischemic reperfusion injury affected by the isozymes of nitric oxide synthase and their gene expression: experimental study]

OBJECTIVE

To study nitric oxide (NO), isozymes of NO synthase (NOS) and their gene expression in the isolated working rat heart after ischemia-reperfusion injury.

METHODS

We quantified the gene expression of the isozymes of NOS by reverse transcription-polymerase chain reaction (RT-PCR), analyzed the myocardial NOS, malondialdehyde (MDA) content, NO, creatine phosphokinase (CPK) in effluent samples from coronary sinus, and measured the heart function before and after ischemia reperfusion. We also studied the effects of dexamethasone(Dex) and bradykinin(BK) introduced into cardioplegia on myocardial ischemia reperfusion injury.

RESULTS

Our study demonstrated that the expression of constitutive NOS(cNOS) mRNA was downregulated and of inducible NOS(iNOS) mRNA upregulated with NO, cNOS decrease and iNOS increase during ischemia reperfusion injury. In Dex-treated group, compared with the control group of ischemia reperfusion, the expression of iNOS mRNA was downregulated, NO and iNOS were reduced, the recovery of myocardial dysfunction was ameliorated and MDA, CPK reduced. In BK-treated group, the expression of NOS mRNA showed no significant change, NO and cNOS were increased. The recovery of myocardial dysfunction was ameliorated. MDA, CPK were also reduced.

CONCLUSION

These results indicated that up- and down-regulation of expression of NOS isozymes could be one of the important mechanisms for myocardial ischemic reperfusion injury. Downregulating the expression of iNOS mRNA and activating cNOS could be helpful in myocardial protection.

Association of petrochemical exposure with spontaneous abortion

OBJECTIVES

To assess the association between petrochemical exposure and spontaneous abortion, a retrospective epidemiological study in a large petrochemical complex in Beijing, China was conducted.

METHODS

Plant employment records identified 3105 women who were married, were 20-44 years of age, and had never smoked. Of those, 3070 women (98.8%) reported at least one pregnancy. From this group, 2853 (93%) of the women participated in the study. According to their plant employment record, about 57% of these women workers reported occupational exposure to petrochemicals during the first trimester of their pregnancy. Trained interviewers administered a standardised questionnaire to this group of women and their husbands, collecting information on reproductive history, pregnancy outcomes, employment history, occupational exposure, smoking habits, alcohol consumption, indoor air pollution, and demographic variables. The results from the womens' first pregnancies were analysed.

RESULTS

There was a significantly increased risk of spontaneous abortion for women working in all of the production plants with frequent exposure to petrochemicals (8.8%; range of 5.8%-9.8%) compared with those working in nonchemical plants (2.2%; range of 0.0%-7.1%). Also, when a comparison was made between exposed and non-exposed groups within each plant, exposure to petrochemicals was consistently associated with an increased risk of spontaneous abortion. The overall odds ratio (OR) was 2.7 (95% confidence interval (95% CI) 1.8 to 3.9) after adjusting for potential confounders. When the analysis was performed with the exposure information obtained from the women' interview responses for (self reported) exposures, the estimated OR for spontaneous abortions was 2.9 (95% CI 2.0 to 4.0). The analysis was repeated by excluding those 452 women who provided inconsistent reports between recalled exposure and work history, and a comparable risk of spontaneous abortion (OR 2.9; 95% CI 2.0 to 4.4) was found. In analyses for exposure to specific chemicals, an increased risk of spontaneous abortion was found with exposure to most chemicals, and the results for benzene (OR 2.5; 95% CI 1.7 to 3.7), gasoline (OR 1.8; 95% CI 1.1 to 2.9), and hydrogen sulphide (OR 2.3; 95% CI 1.2 to 4.4) were significant.

CONCLUSION

An increased risk of spontaneous abortion was found associated with the exposure to petrochemicals, including benzene, gasoline, and hydrogen sulphide.

[The effect of cimeiguo on micronuclei in mice induced by cooking lampblack]

The effect of Cimeiguo on micronuclei in mice induced by cooking lampblack is studied. The results show that the number of micronulei induced by cooking lampblack are increased sighificantly (P > 0.01) with dose-response relationship and inhibited by Cimeiguo.