Direct in situ transcriptase polymerase chain reaction for the detection of Enterovirus genome in liver tissues

In vivo tracking of 111In-labeled bone marrow mesenchymal stem cells in acute brain trauma model

INTRODUCTION

This study was to evaluate the in vivo distribution of intravenously transplanted bone marrow-derived mesenchymal stem cells (BMSCs) in an acute brain trauma model by (111)In-tropolone labeling.

METHODS

Rat BMSCs were labeled with 37 MBq (111)In-tropolone. Their labeling efficiency and in vitro retention rate were measured. The viability and proliferation of labeled BMSCs were evaluated for 14 days after labeling. The biodistribution of (111)In-labeled BMSCs in trauma models was compared with those of sham-operated rats and normal rats on gamma camera images. The migration of (111)In-BMSCs to the traumatic brain was evaluated using confocal microscope.

RESULTS

The labeling efficiency of (111)In-BMSCs was 66+/-5%, and their retention rate was 85.3% at 1 h after labeling. There was no difference in the number of viable cells between (111)In-BMSCs and controls at 48 h after labeling. However, the proliferation of (111)In-BMSCs was inhibited after the third day of labeling, and it did not reach confluency. On gamma camera images, most of the (111)In-BMSCs uptake was observed in the liver and spleen at the second day of injection. The brain uptake of (111)In-BMSCs was detected prominently in trauma models (1.4%) than in sham-operated (0.5%) or normal rats (0.3%). Radiolabeled BMSCs were observed at the traumatic brain on the confocal microscope as they have a homing capacity, although its proliferation capacity was suppressed.

CONCLUSION

Although growth inhibition by (111)In-labeling need to be evaluated further prior to use in humans, (111)In-labeled BMSCs are useful for the tracking of intravenously transplanted mesenchymal stem cells in brain disease models.

The mechanism of chronic coxsackievirus B hepatitis in rabbits

The pathophysiology of chronic hepatitis in rabbits infected with coxsackievirus B5 (CVB5), (strain Mitchell) was investigated. Three-week-old male New Zealand White rabbits were inoculated intraperitoneally with 1 x 10(5) plaque forming units of virus. Every 3 months for 15 months postinoculation (p.i.) groups of animals were sacrificed for the following tests: interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-beta cytokine levels by enzyme-linked immunosorbent assay (ELISA); splenic natural killer (NK) cell function; sequence of a 154-bp section of the 5' noncoding region; antihepatocyte autoantibodies; histologic examination; in situ polymerase chain reaction (ISPCR) of the liver; neutralizing antibody response to CVB5; and viral cultures of liver, spleen, blood, brain, heart, skeletal muscle, and pancreas samples. Histologic evidence of hepatocyte necrosis was evident at each time point, although few inflammatory cells were seen. Liver samples were positive at each time by ISPCR, with viral nucleic acid localized to hepatocyte cytoplasm. Other cells in the liver did not stain. No hepatocyte autoantibodies were detected, and there was no elevation of intrahepatic cytokine levels compared to uninfected controls. There were no mutations in the virus over time. A vigorous neutralizing antibody response to CVB5, Mitchell was generated, but splenic natural killer (NK) function and numbers of splenic NK cells were significantly decreased. Virus culture was positive at 3 months, but negative at further time points. Cultures were negative at 3 months for the other tissues tested. Thus, CVB5, Mitchell causes a chronic hepatitis in rabbits, with virus limited to hepatocyte cytoplasm and no evidence of autoimmunity.

Successful application of indirect in-situ polymerase chain reaction to tissues fixed in Bouin's solution

AIMS

To evaluate the value of polymerase chain reaction-in situ hybridization (PCR-ISH) for the detection of human papillomaviruses (HPV) in paraffin sections of cervical biopsies fixed either in 10% formalin or in Bouin's solution.

METHODS AND RESULTS

We analysed 40 biopsies from Italian women infected with the human immunodeficiency virus type 1 (HIV 1). In-situ hybridization techniques were performed with commercial biotinylated probes. The PCR-ISH was carried out by the 'hot start modification'. Cervical intraepithelial neoplasia (CIN) was found in 23 of 40 patients (57. 5%); eight cases showed condylomatous features. Human papillomavirus was detected in 42.5% by ISH and in 65% by PCR-ISH. Sixty-nine per cent of positive biopsies contained HPV 16, 18, 31 and 33. HPV 6 and 11 were found only in condylomata acuminata samples.

CONCLUSIONS

The results point to a high incidence of HPV infection as well as of CIN in HIV-positive patients. Human papillomavirus type 16 appears to be most frequently associated with CIN. Polymerase chain reaction-ISH is more sensitive than ISH in the detection and typing of HPV DNA both in clinical and in 'latent' infections. The two techniques yielded the same results with either formalin- or Bouin's-fixed material.

Demonstration of persistent enterovirus in the pancreas of diabetic mice by in situ polymerase chain reaction

BACKGROUND

Although Enterovirus (EV) do not persist in the tissue, which is essential to maintain autoimmunity, they have been associated as the cause of chronic autoimmunity in some cases of insulin dependent diabetes mellitus (IDDM). Convincing reports, demonstrating persistent EV infections in the pancreases, are rare.

OBJECTIVES

To determine the role of EV in IDDM, a mouse model was tested and i situ polymerase chain reaction (ISPCR) developed. The major problem of ISPCR are the high amounts of non-specific staining. In the current study we developed an ISPCR protocol which minimised non-specific staining and allowed the accurate localisation of the viral RNA in the tissue.

STUDY DESIGN

Five mice were infected with coxsackievirus group B4, sacrificed 7 weeks later and the pancreases were harvested. The EV nucleic acid were localised and detected in the pancreases by ISPCR.

RESULTS

In the current study non-specific staining of ISPCR, due to DNA repair and diffuse artefacts, were minimised and the EV nucleic acids were localised in the beta cells of the endocrine pancreases in all five diabetogenic mice.

CONCLUSION

This study demonstrates an association of viral RNA with the development of diabetes in mice and the usefulness of ISPCR to determine the role of EV in IDDM.

Comparison of procedures for the detection of enteroviruses in murine heart samples by in situ polymerase chain reaction

A protocol for the in situ polymerase chain reaction (IS-PCR) detection of viral nucleic acid in the heart tissue of four-to-five-week-old CD1 mice infected with coxsackievirus B3 (CBV3) Nancy strain is described. To compare the effects of formalin concentration on the IS-PCR process, two different concentrations (10 and 37%) were employed. Using 37% formalin, 25 PCR cycles were sufficient and a permeabilization step could be omitted. However, postfixation of tissues with 4% paraformaldehyde and 100% ethanol after the deparaffinization, reverse transcriptase and amplification steps was required in order to minimize artefacts. When the tissues were fixed in 10% formalin, postfixation with 4% paraformaldehyde was not required, but a permeabilization step had to be employed and 40 cycles of PCR amplification were needed. To detect the PCR product in the 10% formalin-fixed samples, incubation with 0.3 U/ml of an anti-digoxigenin antibody conjugated to alkaline phosphatase was performed for 90 min. When 37% formalin-fixed samples were used, the concentration of the antibody conjugate had to be increased to 3 U/ml and the exposure time was decreased to 30 min. Enterovirus (EV) nucleic acid was detected in the cytoplasm of myocytes. Thus, IS-PCR was successful in localizing EV nucleic acid in the cytoplasm of myocytes in mice infected with a cardiotropic strain of CBV3. Using this technique, 10% formalin-fixed tissues gave better results than 37% formalin-fixed tissues.