Standardized through-and-through critical size defects were created in rat mandibles. After 12 weeks, the sites revealed a massive ingrowth of soft connective tissue, forming a transosseous core filling the defects. Upon reentry, the soft tissue inside the remaining bone defects was removed. On one side of the jaw, the defect was covered both buccally and lingually with an expanded polytetrafluoroethylene (e-PTFE) membrane, but on the other side no membrane was placed. Histologic analysis after 6 weeks revealed an essentially complete healing with bone of the membrane-covered defects. No cartilage was present in any of the specimens. At the control sites (no membrane), the amount of newly produced bone showed variations, most through defects revealing the presence of a remaining central portion of connective tissue. This investigation thus showed that predictable and successful bone regeneration can be achieved by the osteopromotive membrane method in treatment of nonunion defects filled with mature connective tissue.

Animals↗

PubMed1994

Presence of autologous neutralizing antibodies against cytomegalovirus (CMV) in serum of human immunodeficiency virus type 1-infected patients shedding CMV in saliva.

This study evaluated whether cytomegalovirus (CMV) neutralizing capacity affected shedding of CMV in saliva in human immunodeficiency virus type 1 (HIV-1)-infected patients and mapped specific epitope reactivity of CMV IgG antibodies. Total CMV IgG titers were significantly higher in symptomatic than in asymptomatic HIV-1-infected patients or controls. All CMV-seropositive patients had neutralizing antibodies to CMV. Shedding of CMV in the saliva of AIDS patients occurs despite the presence of serum antibodies with a high capacity to neutralize autologous CMV isolates. The highest IgG reactivity against a CMV envelope protein (gp116), represented by a peptide, was found in patients with advanced HIV disease. In contrast, identical IgG reactivities against a peptide representing the CMV matrix protein were observed in healthy controls and HIV-1-infected persons.

Adult↗

PubMed1994

The use of the stable isotope 44Ca in studies of calcium incorporation into dentin.

The incorporation into rat incisor dentin of two calcium isotopes, the stable 44Ca and the radioactive 45Ca, was studied using secondary ion mass spectrometry (SIMS) step-scanning and imaging, and autoradiography, respectively. The results demonstrated a time-dependent incorporation of the calcium isotopes into the mineral phase of dentin. With the SIMS step-scanning, detecting 44Ca, the ion yield was high in the odontoblasts 2 min after intravenous injection. After 10 min a marked increase in signal intensity was found at the dentin mineralization front. This result was consistent with those obtained by 45Ca autoradiography; a peak of incorporation occurred 10 min after injection of the isotope. Likewise, localization of 44Ca to the mineralization front could be demonstrated 10 min after injection by SIMS imaging. In images obtained at earlier intervals, no such increase in ion yield could be detected. The results show that the nonradioactive, stable isotope 44Ca can be used as a marker for biomineralization in a similar way to radioactive 45Ca.

Animals↗

PubMed1994

Comparative evaluation of nine kits for rapid diagnosis of infectious mononucleosis and Epstein-Barr virus-specific serology.

Rapid diagnosis of Epstein-Barr virus (EBV)-associated infectious mononucleosis was compared by using nine kits and EBV-specific serology. Specific antibodies indicative of primary EBV infection were detected in 46 of 108 (43%) serum samples of infectious mononucleosis patients. The sensitivities and specificities of the rapid kits varied from 63 to 84% and 84 to 100%, respectively.

Adolescent↗

PubMed1994

Localization of ornithine decarboxylase in mouse teeth. An in vitro and in vivo study.

Ornithine decarboxylase (ODC), a key enzyme in polyamine biosynthesis, and thus in tissue growth and development, has been localized in mouse dental tissues, in vivo as well as in vitro by light and electron microscopic autoradiography with radiolabeled alpha-difluoromethylornithine ([3H]DFMO). Mandibular first molar germs from day-18 fetuses were incubated in vitro in the presence of [3H]DFMO and processed for autoradiography. For ODC localization in vivo, 3-day old puppies received [3H]DFMO by injection. As controls, puppies were injected either with unlabeled DFMO, or with cycloheximide before administration of isotope. Kidneys and mandibles were excised and processed for autoradiography. In vitro, labeling was found in all cell types of the tooth germ, but with a more intense labeling in ameloblasts and odontoblasts. In both these, radioactivity decreased from the tip of the cusps to the cervical loop. In vivo the binding of [3H]DFMO in cells of the ameloblast and odontoblast lineages, respectively, showed a gradual increase form the posterior end of the incisor to its anterior end. The distribution of radioactivity in the kidney was in accordance with findings by others. Both the kidney and tooth cell labeling decreased strongly after cycloheximide treatment. The results show that ODC is expressed in tooth-forming cells, and that ODC is not only present in differentiating cells but occurs at higher amounts in mature, secreting cells. The findings suggest that polyamines have a central role in tooth development.

Aging↗

PubMed1993

[Influenza A Beijing is approaching. 2 new strains in this season's vaccine].

Explore the source record for details and available documents.

Humans↗

PubMed1993

Epstein-Barr virus DNA in cerebrospinal fluid from patients with AIDS-related primary lymphoma of the central nervous system.

Epstein-Barr virus (EBV) is constantly associated with AIDS-related primary lymphomas of the central nervous system (CNS). To assess whether EBV DNA in cerebrospinal fluid (CSF) could be used as a tumour marker, CSF samples that had been taken within 180 days before death from 85 patients with HIV infection and neurological disorders at necropsy were examined retrospectively by nested polymerase chain reaction (PCR) for EBV. Histologically evident primary CNS lymphomas were found in 17 patients, and EBV was shown in tissue by in-situ hybridisation in 16 of the 16 cases examined. All 17 patients with primary CNS lymphoma had EBV DNA in CSF. EBV DNA was found in CSF from 1 of 68 HIV-infected patients without histologically detectable lymphoma at necropsy. PCR for EBV DNA in CSF was 100% sensitive and 98.5% specific for AIDS-associated primary CNS lymphoma, and may be useful as a diagnostic tumour marker.

Base Sequence↗

PubMed1993

Human immunodeficiency virus type 1 and cytomegalovirus in saliva.

The aim of this study was to evaluate whether HIV-1 or cytomegalovirus (CMV) may contribute to oral lesions frequently found in patients with the acquired immunodeficiency syndrome (AIDS). Saliva samples from 63 HIV-1 positive patients and 21 healthy controls were tested for the presence of HIV-1 and CMV using the polymerase chain reaction (PCR) and virus isolation. CMV IgG titres in serum were also compared in the different groups. HIV-1 RNA, but not DNA, was detected in saliva from 15% (9 out of 59) of the HIV-infected patients. There was no correlation between the presence of HIV-1 RNA and oral symptoms in the patients. CMV DNA was detected significantly more frequently in samples from HIV-1 seropositive than from seronegative patients. CMV was detected in saliva from AIDS patients more often than in saliva from patients with mild or no symptoms. CMV IgG titres were also significantly higher in symptomatic than in asymptomatic patients. There was a significant correlation between the presence of CMV DNA and necrotizing gingivitis, and oral Kaposi's sarcoma in the patients, and also between these lesions and the stage of disease. This does not prove that CMV causes these oral lesions, but a direct or indirect role for CMV cannot be excluded.

Acquired Immunodeficiency Syndrome↗

PubMed1993

Multiple viral infections in HIV-infected children with chronically-evolving hepatitis.

Hepatic involvement was investigated in 31 children with perinatal HIV-1 infection, who were followed for 2-82 months (mean 30.5). Liver disease, as revealed by increased aminotransferase levels, liver biopsy or necroscopy, was diagnosed in 18 children (58%), of which 7 (22.5%) had acute hepatitis and 11 (35.5%) showed chronic liver disease. Overall, 40 persistently active or recurrent viral infections, as demonstrated by positive culture and/or detection of serum DNA, specific IgM, IgA and high levels of IgG, were revealed in the children with liver disease, while 12 similar infections were detected in 13 children without liver disease (p < 0.001). In particular, the children with liver disease showed a significantly (p < 0.002) higher incidence of cytomegalovirus (CMV) infections than children without liver disease (13 versus 3). Moreover, hepatitis C and B virus infections were revealed only in children with liver disease (5 and 1 patients, respectively). Clinical outcome showed a significantly (p < 0.001) higher mean survival in the children without liver disease than those with liver disease (47.5 versus 18.2 months). In fact, nine of the children with liver disease (50%) died, as opposed to only one of the children without liver disease (7.7%; p = 0.01). Based on these findings, liver disease is indicative of a poor prognosis in children with HIV infection, being related to the presence of multiple active viral infections.

AIDS-Related Opportunistic Infections↗

PubMed1993

Creation of new bone by an osteopromotive membrane technique: an experimental study in rats.

Domes, 5 and 8 mm in diameter, were made of expanded polytetrafluorethylene membrane with different degrees of stiffness and internodal distance. The domes were placed on denuded calvarial bones of rats and covered by the skin and periosteal flaps. Histologic evaluation 9 to 16 weeks after surgery showed the formation of various amounts of new bone on the calvarial bone surface inside the domes. The amount of bone neogenesis was dependent on membrane qualities, such as stiffness and porosity, and the length of the healing period. In the most successful experiments, about 80% of the dome volume was filled with newly formed bone, whereas in other experiments considerable amounts of connective tissue were present. Using bioabsorbable membrane domes proved less successful in that they did not maintain their shape and thus did not provide space for bone formation. This study showed that it is possible to obtain bone neogenesis by an osteopromotive membrane technique. This possibility may eventually be of great significance for reconstructive surgery.

Animals↗

PubMed1993

Bone regeneration by the osteopromotion technique using bioabsorbable membranes: an experimental study in rats.

An osteopromotive technique has been developed that allows improved bone regeneration as well as bone neogenesis using porous, inert, nondegradable membranes made of expanded polytetrafluoroethylene (e-PTFE). For certain applications, however, it would be advantageous to use bioabsorbable membranes (BAMs), thus avoiding a surgical reentry for membrane removal. In this randomized comparison study the osteopromotive potential of BAMs was investigated in standardized "critical size defects" (5 mm in diameter) in the rat mandible. Three membrane types were tested and comparisons were made with e-PTFE membrane. The BAMs consisted of polylactic/polyglycolic acid copolymers designed to give the membranes different absorption times when implanted in the tissue. Histologic analysis after healing periods of 1 to 12 weeks demonstrated the BAMs to be well tolerated by the tissue, causing just a mild inflammatory reaction along the membrane surfaces as long as the material remained in the tissue. The BAMs were found to be as efficient as e-PTFE membranes in that the bone repair was not significantly different with any of the four membrane types. However, healing in conjunction with one type of BAM seemed to occur somewhat more rapidly. Some cartilage was present at the early healing stages in the defects treated with BAMs, but disappeared at later stages. The results of this study show that BAMs are a valid alternative to e-PTFE membranes to improve bone regeneration, but indicate that further technical development of the membrane material is necessary.

Absorption↗

PubMed1993

Cytomegalovirus viraemia and specific T-helper cell responses as predictors of disease after allogeneic marrow transplantation.

Risk factors for cytomegalovirus viraemia and disease, the relation between viraemia and disease, effect of antiviral treatment, and T-helper cell response to cytomegalovirus antigen were analysed retrospectively among 279 patients who underwent bone marrow transplantation at Huddinge Hospital. Ninety-one of 279 (32.6%) patients developed viraemia. Donor and recipient pre-transplant serologic status and degree of acute graft-versus-host disease were independent risk factors for viraemia. Forty-nine patients (17.6%) developed cytomegalovirus disease and 44 of these patients had viraemia. Seventeen patients (6%) developed cytomegalovirus pneumonia and 14 of these patients had preceding viraemia. Among patients with viraemia, acute graft-versus-host disease and total body irradiation were risk factors for pneumonia. Antiviral treatment initiated within 7 d of development of viraemia was associated with lower risk for development of pneumonia (P < 0.05). Sixty-seven patients with viraemia were repeatedly tested by lymphocyte stimulation with cytomegalovirus antigen. No patient who developed cytomegalovirus pneumonia had measurable specific helper T-cell response at the time of viraemia detection compared to 42% of patients with other concurrent or subsequent cytomegalovirus disease, and 75% of patients without subsequent disease. We conclude that viraemia is a major risk factor for development of cytomegalovirus disease. Furthermore, early antiviral treatment based on detection of viraemia can be effective in preventing cytomegalovirus disease. The length of antiviral treatment might be decided through measurements of the helper T-cell response to cytomegalovirus antigen.

Adolescent↗

PubMed1993

T and B cell responses to cytomegalovirus antigens in healthy blood donors and bone marrow transplant recipients.

We measured the production of interferon-gamma (IFN-gamma) from single T cells and the T cell proliferative response to different cytomegalovirus (CMV) antigens in healthy blood donors and bone marrow transplant recipients. The antigens consisted of a CMV nuclear antigen (CMV na) containing the pp65-kDa matrix protein and the immediate early antigens but lacking CMV glycoproteins, and an antigen comprising native CMV glycoproteins (CMV gp). We also measured the IgG antibodies to CMV na and CMV gp. The T cells reacted to CMV na in CMV seropositive blood donors both with the production of IFN-gamma and with proliferation, while bone marrow transplant recipients had a deficient T cell response. After stimulation with CMV gp, no T cell response could be observed in CMV seropositive subjects. IgG antibodies to CMV na coexisted in plasma with similar levels of antibodies to CMV gp.

Adolescent↗

PubMed1993

Mineral induction in vivo by dentine proteins.

The mineral-inductive capacity of polyanionic noncollagenous proteins, isolated from calcified tissues, has earlier been demonstrated in vitro. These macromolecules possess this capacity, provided that they are immobilized on a solid support, whereas in solution they inhibit crystal mineral induction and growth. The present study demonstrates this capacity also in vivo. Phosphoprotein, proteoglycan and gamma-carboxyglutamate-containing protein (Gla-protein) of the osteocalcin type were covalently coupled to AH-Sepharose beads, and these were implanted subcutaneously in minipigs for periods between 3 and 24 weeks. Similarly, demineralized rat incisor dentine was implanted for 3 weeks, as was predentine dissected from dentinogenically active bovine incisors. The results were analyzed by scanning electron microscopy and energy dispersive X-ray analysis. Dentine proteoglycan and phosphoprotein coupled to beads were found to be inducers of calcium/phosphate-containing mineral, whereas the efficacy of Gla-protein was negligible. Dissected predentine did not induce any mineral, but demineralized dentine preparations, still containing some noncollagenous anionic components, were found to induce mineral. The results indicate that macromolecules such as proteoglycan and phosphoprotein may be responsible for mineral induction during mineralization of calcified tissues. The results further imply that such molecules may be of importance for the remineralization of dentine in conjunction with the caries process.

Animals↗