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Biomedical subjects

A Linde

Publications and source records attributed to A Linde.

At least 109 records · Page 6Linked to original sources
PubMed1997

Repeated bone repositioning in the growing rabbit calvarium hampers bone segment incorporation.

There has been concern among surgeons that multiple extended craniofacial procedures might be detrimental to the viability of the involved skeletal structures. This study aimed to explore the result of repeated bone repositionings in the growing rabbit calvaria. Seven immature rabbits were subjected to a three-stage surgical procedure, implying that four calvarial bone segments were originally harvested and repositioned according to a rotational scheme; after 6 weeks only three of the bone segments were harvested and repositioned and, finally, after an additional period of 6 weeks, two segments were repositioned. The results were evaluated by radiographic, histologic (with a special scoring system), and histomorphometric analysis. It was found that one or two cranioplasties did not markedly affect graft incorporation, but three procedures significantly reduced graft revascularization and integration. The findings are discussed with special reference to syndromic craniofacial disorders.

Animals↗
PubMed1997

Absence of seven human herpesviruses, including HHV-6, by polymerase chain reaction in CSF and blood from patients with multiple sclerosis and optic neuritis.

Several members of the herpesvirus family have been implicated in the pathogenesis of multiple sclerosis (MS). Recently, HHV-6 viral antigen has been demonstrated in association to MS plaques, as well as DNA from human herpesvirus 6 (HHV-6) in cerebrospinal fluid from a few MS patients by polymerase chain reaction (PCR). In the present study, CSF from patients with MS, optic neuritis and other neurological diseases, as well as consecutive CSF and serum samples from MS patients included in a clinical trial with acyclovir, were analysed by nested PCR for the presence of DNA from herpes simplex virus 1 and 2, Epstein-Barr virus, varicella zoster virus, cytomegalovirus, human herpesvirus 6 and 7. No virus DNA was found in any CSF (n = 115) or serum (n = 116) sample. These findings argue against a continuous disseminated herpesvirus infection in MS, but do not rule out a lesion-associated, low-grade herpesvirus infection within the MS brain.

Adolescent↗
PubMed1997

Guided bone regeneration in dental implant treatment using a bioabsorbable membrane.

The aim of this study was to evaluate an osteopromotive technique, using a bioabsorbable membrane, for its ability to restitute bone over buccal fenestration and dehiscence defects following fixture installation. 11 patients requiring dental implant treatment and exhibiting sufficient vertical height of the maxilla and compromised bucco-palatal dimensions, as determined clinically and radiographically, were included in the study. 17 Brånemark titanium fixtures were placed with buccal defects which were augmented by a bioabsorbable membrane, Resolut. No complications were observed post-operatively. At 6-8 months, abutment connection was performed, and clinical evaluation of the healed defect area was made. The number of exposed buccal threads at fixture installation (median 8; range 2-19), and abutment connection (median 0; range 0-5), respectively, was compared. Out of the 17 fixtures; 14 exhibited complete coverage with bone, whereas 3 showed some remaining threads. A small punch biopsy taken at abutment connection in an area where the membrane had been placed showed a combination of dense connective tissue and bone. Radiographic evaluation of the marginal periimplant bone level is in progress and results to date show a median bone loss of 1.2 mm after a loading period of 4-6 months. Results show that fixture dehiscence and fenestrations, augmented with this bioabsorbable membrane, demonstrate a highly significant amount of new bone formation.

Aged↗
PubMed1997

Evaluation of three commercial enzyme-linked immunosorbent assays and two latex agglutination assays for diagnosis of primary Epstein-Barr virus infection.

Three commercially available enzyme-linked immunosorbent assays (ELISAs) from Gull, Biotest, and Behring (Enzygnost) and two latex agglutination tests for heterophile antibodies (Monolatex [Biotest] and Mono-Lex [Trinity Laboratories]) were evaluated for the diagnosis of primary Epstein-Barr virus (EBV) infection and EBV seropositivity. Two hundred fourteen consecutive samples from 197 patients with symptoms of primary EBV infection were analyzed by the five assays at a clinical microbiology laboratory. The samples were also analyzed independently by immunofluorescence methods at a reference laboratory. According to the reference methods, 37 patients (40 serum samples) had primary EBV infections, 120 patients (127 serum samples) had had past EBV infections, 33 patients (36 serum samples) were seronegative, and 7 patients (11 serum samples) exhibited atypical reactions. The respective sensitivities and specificities for the diagnosis of primary EBV infection were 95 and 100% for the Gull assays, 100 and 94% for the Biotest assays, and 100 and 89%, for the Enzygnost assays. The Monolatex and Mono-Lex methods showed similar sensitivities and specificities (78 to 85% and 100 to 99%, respectively) for the diagnosis of primary EBV infection. This study demonstrates the usefulness of commercially available assays for the rapid diagnosis of primary EBV infection, but also the importance of large-scale testing of routine samples before choosing an assay.

Antibodies, Viral↗
PubMed1997

Antigen detection: the method of choice in comparison with virus isolation and serology for laboratory diagnosis of herpes zoster in human immunodeficiency virus-infected patients.

Ninety-two adult human immunodeficiency virus (HIV)-infected patients with suspected herpes zoster were included in a study. The clinical diagnosis of herpes zoster was verified by examination of blister cell and fluid material or serum samples. Antigen detection by a direct immunofluorescence assay with a fluorescein isothiocyanate-labelled monoclonal antibody, virus isolation, and serologic methods (in-house varicella-zoster virus [VZV] immunoglobulin G [IgG] and IgM enzyme-linked immunosorbent assays and the commercial Enzygnost assay) were compared. The direct immunofluorescence assay was found to be the most sensitive method, diagnosing 85 of 92 infections (92%), while the sensitivity of virus isolation was 65% (60 of 92 patients). Despite the use of two different serological methods, only 60 of 92 patients (65%) had significant VZV IgG titer rises, and only 26 of 92 patients (28%) had detectable VZV IgM. The lack of a VZV IgG antibody titer rise was found to correlate with low CD4 counts in peripheral blood and high VZV IgG titers in the acute-phase serum sample. The frequency of IgM-positive sera was lower than that expected from reports of studies with patients without AIDS. This may be related to early antiviral treatment or deficient antibody production due to the HIV-related immunosuppression. There was no significant difference in CD4 counts between VZV IgM-positive and -negative patients.

AIDS-Related Opportunistic Infections↗
PubMed1997

Pelvic floor findings in urinary incontinence--results of conditioning using vaginal cones.

BACKGROUND: Conservative treatment of urinary incontinence (UI) may be more reliable if it is associated with improved testing of pelvic floor function. The results of cone training in patients and healthy controls are compared. METHODS: Voluntary contractions of pelvic floor muscles in 16 women with genuine stress incontinence, 14 with mixed stress/urge incontinence, and eight healthy controls were assessed by digital transvaginal palpation, manometry, and inspection using the so-called speculum-lift test. In addition, the capability to hold vaginal cones was investigated. All examinations were done before and after four-week cone training (Femcon 20-70 g). RESULTS: Prior to cone training, no pelvic floor response was recordable from eight women (27%) by palpation and from seven women (23%) by inspection. After training, contractions were restored in all women. The best post-training results were obtained by palpation (27 positive responses), followed by manometry (25 women, 83%), and speculum-lift test (13 women, 43%). The capability to hold vaginal cones was also improved. Initial weights in 15 UI patients (50%) were lower (cone No. 1-2) than in eight healthy women (cone No. 5). Average contractility increased from 5 to 9.7 mmHg in patients and from 17.5 to 23.1 mmHg in healthy women. Twenty-four patients (80%) were cured (57%) or improved (23%). Twenty-six asked for continuation of cone training. CONCLUSIONS: Pelvic floor conditioning with vaginal cones is a good alternative to poor acceptance or insufficient availability of conventional exercises.

Adult↗
PubMed1997

Treatment of segmental defects in long bones using osteopromotive membranes and recombinant human bone morphogenetic protein-2. An experimental study in rabbits.

The purpose of this study was to investigate whether barrier membranes that were earlier shown to promote bone healing in the craniofacial skeleton are capable of producing bone healing in long bone. defects by themselves or in combination with recombinant human bone morphogenetic protein 2 (rhBMP-2). Segmental defects (10 mm long) in the rabbit radius, known to heal as pseudoarthrosis-like defects, were used as the experimental model. Treatment with expanded polytetrafluoroethylene membranes (GORE-TEX Membrane) (n = 10) resulted in only minor amounts of bone formation within the defect and collapse of the membranes was common. When placement of membranes was combined with implantation of rhBMP-2 in a beaded biodegradable copolymeric PLA/PGA carrier, total bony bridging of the defects was accomplished within 10 weeks (n = 5). Osteopromotive membranes combined with mBMP-2 can therefore bring about complete healing of long bones. The membranes exclude soft tissue from the defect and at the same time keep the growth-stimulatory implant in place and maintain the anatomical contour of the bone. The combination of osteopromotive membranes and rhBMP-2 may be of. value in reconstructive bone surgery.

Animals↗
PubMed1996

Lymphotropic herpesviruses in allogeneic bone marrow transplantation.

Human herpesvirus-6 (HHV-6), human herpesvirus-7 (HHV-7), Epstein-Barr virus (EBV), and human cytomegalovirus (CMV) DNA were repeatedly assayed in peripheral blood leukocytes from 37 allogeneic bone marrow transplant (BMT) patients by polymerase chain reaction. Before BMT, HHV-6 DNA was detected in 8 (22%) patients. HHV-7, EBV, and CMV DNA were detected in 21 (57%), 10 (27%), and 1 (3%) patient, respectively. After BMT, HHV-6 DNA was detected in 26 (70%), HHV-7 in 21 (57%), EBV in 28 (76%), and CMV in 21 (57%) patients. Thirty-two (87%) patients were positive with more than one virus. HHV-6, HHV-7, and EBV DNA were found earlier than CMV DNA in most patients after BMT. The proportions of HHV-6-positive samples during the first 3 months after BMT were higher in the patients with either delayed granulocyte engraftment (P = .04, Fisher's exact test) or delayed platelet engraftment (P = .001, Fisher's exact test). The HHV-6 DNA in samples from the patients with delayed engraftment was confirmed to be variant B. The detection of any lymphotropic herpesvirus was not related to the development of acute graft-versus-host disease (aGVHD). High-dose acyclovir (ACV) prophylaxis significantly (P < .01) reduced the proportion of HHV-6-positive samples and tended to lower HHV-6 DNA levels (P = .06). Our data indicate that HHV-6 variant B can inhibit marrow engraftment and that high-dose ACV may be beneficial to engraftment after BMT by preventing HHV-6 reactivation. No relation between the proportions of HHV-7-, EBV-, and CMV-positive samples in the first 3 months and engraftment or aGVHD was found.

Acyclovir↗
PubMed1996

Systemically and locally administered growth hormone stimulates bone healing in combination with osteopromotive membranes: an experimental study in rats.

Growth hormone (GH) is known to be of a major importance for longitudinal bone growth, but its local effects on osteogenesis and, thus, regeneration of bone defects are less known. The aim of this investigation was to study whether GH, systemically or locally administered, has any stimulatory effects on local osteogenesis, utilizing standardized, membrane-covered, transosseous defects (5 mm diameter) in mandibles of adult albino rats. The study also addressed the question of whether GH might be a feasible option to further promote bone regeneration and neogenesis in conjunction with expanded polytetrafluoroethylene (e-PTFE) "osteopromotive" membranes (GORE-TEX). Human GH (hGH; 0.2, 2, 20, 200 micrograms/day), bovine GH (bGH; 200 micrograms/day), prolactin (200 micrograms/day) or saline was administered systemically by means of mini-osmotic pumps, implanted subcutaneously at the back of the animal. Healing was analyzed after 2, 3, and 4 weeks. Healing was also studied after local administration, just outside the defects, of hGH (0.2, 2, 20 micrograms/day) via catheters connected to mini-osmotic pumps during 4 weeks. Human GH and bGH stimulated local bone formation compared to saline and prolactin. Bone formation was significantly promoted by systemically administrated hGH, after 3 weeks and at 2 micrograms/day or higher concentrations. Enhanced bone formation was also found after 4 weeks in animals given 0.2, 2 and 20 micrograms/day of hGH locally, compared to local administration of saline. The results show that GH exerts a direct, nonliver mediated effect on bone tissue. Moreover, the study suggests that hGH may be used to stimulate bone healing and formation in conjunction with osteopromotive membranes.

Animals↗
PubMed1996

Effects of different osteopromotive membrane porosities on experimental bone neogenesis in rats.

Biologically inert expanded polytetrafluorethylene (e-PTFE) membranes (GORE-TEX) have earlier been shown to improve healing of different types of bone defects, to be able to restore earlier existing bone, and to produce bone neogenesis. This study was performed to investigate the influence of membrane porosity on the osteopromotive efficacy and to determine bone neogenesis times in the rat. Three different e-PTFE membrane qualities with different porosities (internodal distances < 8, 20-25 and 100 microns) and four healing periods (6, 12, 18 weeks and 6 months) were studied. Dome-shaped e-PTFE membranes (5 mm inner diameter) were placed on denuded rat calvaria and covered with the periosteum and skin. After the respective time intervals, specimens were prepared for histology, and the bone obtained within the domes was quantified by an image analysis system. The results confirmed that it is possible to produce new bone by the use of the osteopromotion technique. The rate of bone neogenesis depended on the quality of membrane used; the membranes with the smallest internodal distance were less efficient than the others in that osteogenesis was somewhat delayed. The amount of new bone achievable was essentially already obtained after 6 weeks with the two most porous membranes, whereas the least porous one lagged behind. After 12 weeks there was no difference in the amount of newly formed bone. There was an obvious time sequence, in that the newly formed bone showed an increased maturity with longer observation periods. The material with the smallest internodal distance did not integrate well with the surrounding soft tissue, leading to a lack of stabilization of the membrane and more soft tissue ingrowth from the side. It is concluded that there is a porosity range within which osteogenesis beneath the membranes is optimal, tissue integration for stability is adequate enough, and soft connective tissue ingrowth is avoided.

Analysis of Variance↗