How to diagnose chronic rejection. A study in porcine intestinal allografts

Porcine small bowel allografts were followed for 18 weeks during immunosuppression with cyclosporine-A (CyA), azatioprine and prednisone. The mucosal alterations noted at the 12th week were epithelial vacuolation and loss of Goblet cells. Moderate infiltration of inflammatory cells, mainly lymphocytes, was found in the lamina propria. In addition, a few grafts exhibited oedema and fibrosis. Vessels already showed endothelial swelling and intimal proliferation at the 12th week. In the submucosa, the infiltration of inflammatory cells was not present till the 18th week. Further changes in the mucosa at the 18th week were the blunting of villi, cuboidal epithelium, crypt abscesses and epithelial atrophy. The histological alterations of mucosa and lamina propria existing in the full thickness biopsies were mostly also detectable in mucosal biopsies, provided that multiple biopsies were taken. Thus these parameters analyzed from mucosal biopsy material are suitable for the diagnosis and monitoring of chronic small bowel rejection. In autopsy, the most prominent features were in the mesenterial arteries: intimal proliferation, vasculitis, proliferation of media and endothelial alterations. The activity of the mucosal disaccharidases maltase and sucrase remained near the initial level till the 12th week and had decreased markedly by the 18th week.

Guided tissue regeneration in conjunction with hydroxyapatite-collagen grafts for intrabony defects. A clinical and radiological evaluation

This clinical and radiological study evaluated the healing of 3 + 2 + 1 wall-combined intrabony defects treated using the guided tissue regeneration technique (GTR) with and without hydroxyapatite-collagen alloplastic graft materials (HAC), in comparison to that of HAC alone and conventional flap surgery (CF). 40 interproximal defects with probing depth > 6 mm were treated in 18 adult periodontitis patients of ages 35-60 years. After non-surgical therapy, the defects were randomly grouped into 4 groups of 10 defects each. These groups were designated: (1) expanded polytetrafluoroethylene membrane (e-PTFE), (2) e-PTFE + HAC, (3) HAC alone and (4) CF. At 6 months, the following changes in parameters were recorded. Mean PPD reduction for each group was 5.83, 5.85, 3.80 and 3.17 mm respectively. PPD reduced very significantly in all groups (p < 0.01), the highest and lowest reductions in PPD being for the e-PTFE + HAC and CF group respectively. Comparison between the 4 groups showed higher PPD reduction in both membrane groups than in either of the non membrane groups (p < 0.05) with the difference between the e-PTFE and CF groups being very highly significant (p < 0.001). Mean attachment gain for the 4 groups was 3.70, 3.80, 2.60 and 2.1 mm, respectively. Similarly attachment gain for all groups was very significant (p < 0.01) and the highest and lowest attachment gains were for the e-PTFE + HAC and CF group respectively. Both membrane groups showed significantly more attachment gain than the CF group (p < 0.05). Change in probing bone level (BL) for the 4 groups was 1.60, 1.90, 1.0 and 0.65 mm respectively. Again the highest changes in BL were recorded for the e-PTFE + HAC group. Significant differences were found between both membrane groups and the CF group (p < 0.05). Radiological evaluation using standardized radiographs and millimeter grids showed change in radiographic bone level at the deepest point of the defect on the radiograph to be 1.50, 1.55, 0.85 and 0.60 mm, respectively and this was significantly higher in both membrane groups than in the CF group (p < 0.05). This study therefore found e-PTFE membranes both alone and when combined with HAC to lead to more attachment gain and bone fill than did HAC alone or CF. It found HAC combined with e-PTFE to perform better although not significantly better than e-PTFE alone.

A clinical and microbiological evaluation of systemic and local metronidazole delivery in adult periodontitis patients

The present study describes results on selected clinical and microbiological parameters obtained by treatment with local (Elyzol) and systemic (Flagyl) use of metronidazole alone and/or mechanical subgingival debridement in adult periodontitis. Patients were randomly divided into local and systemic treatment groups each comprising 5 individuals in each of whom 4 sites (one site/ quadrant) with a probing depth of > or = 5 mm were selected and treated with separate treatment modalities. The overall treatment design provided 6 different test groups. Groups of quadrants received: (1) scaling and root planing; (2) local metronidazole treatment; (3) systemic metronidazole treatment; (4) local metronidazole combined with scaling and root planing; (5) systemic metronidazole combined with scaling and root planing; (6) no treatment. The microbiological and clinical effects of treatment modalities were monitored over a period of 42 days. All treatments resulted in clinical improvements (gingivitis, probing pocket depth, attachment level) except for the untreated group. Parallel to the clinical changes, all treatments reduced the number of total bacteria and proportions of obligately anaerobic microorganisms. Although both of the combined treatment groups responded to therapy with better resolution of infection that the pure mechanical and pure metronidazole treatments, local metronidazole in combination with scaling and root planing seems to be more effective in terms of producing both clinical and microbial improvements.

The kidney/pancreas transplant: an alternative for type I diabetics

Whole pancreas transplantation is becoming a real and safe option for treatment of type 1 diabetic patients. Several controversial issues are still waiting for answers. Portal drainage has been reported to be a possible alternative to systemic drainage, but no prospective data comparing the two techniques is available yet. Further data comparing enteric and bladder drainage is also overdue. With new immunosuppressive agents, isolated pancreas transplantation may also gain better survival and wider application.

Dynamic swan neck deformity in a patient with Ehlers-Danlos syndrome

A patient with type I Ehlers–Danlos syndrome with a congenital hand deformity described as a “dynamic swan neck deformity” is presented and causes of the deformity are discussed.

Medical education in Turkey 1996

Medical education in Turkey has certain similarities with systems in the West, and is struggling to train its doctors to the highest standard. However, as a country it remains very much in between the cultures of East and West. Although the overall organisation of medical training is continually changing, and individual medical schools have varying ideals, the aim of this article is to provide an overview of the current system for training student doctors in Turkey.

A new method for standardization of intraoral radiographs

Standardization of intraoral radiographs is necessary for longitudinal studies of alveolar bone changes. Several methods of standardizing have been developed. These all involve fixing the geometric relations between the object, the x-ray tube, and the film. This usually involves a film holder, mounted on an occlusal stent and connected to the x-ray tube via an adapter ring. There is, however, a problem of compatibility between various commercial adapter rings and film holder assemblies. In an attempt to overcome this problem, we developed a method of producing cast acrylic adapters by making a plaster cast from a silicon rubber impression of the x-ray tube. The adapter was devised so that radiographs could be taken of all four segments using the same standard commercially available film holder. A total of 128 radiographs were taken from 42 patients who underwent various types of periodontal surgery; 64 were taken preoperatively and 64 at 6 months postoperatively. These pairs were superposed and approximately 58% were found by qualitative inspection to show total matching of geometric outlines as well as maintenance of position on the film, and approximately 73% to show geometric matching. Changes in alveolar bone height were evaluated for 11 of these totally matching pairs by counting millimetric grids and by a computer-based indirect digital imaging system. These were found to correlate satisfactorily (r = .63).

The relation of microbiologic data to aspartate aminotransferase enzyme activity in gingival crevicular fluid

Gingival crevicular fluid (GCF), reflects the immune and inflammatory reactions and is itself a location for specific host-microbe interactions that lead to periodontal diseases. Aspartate aminotransferase (AST) is one of the components of GCF that is released as a result of cell death. In this study, 40 periodontal sites in 10 early onset periodontitis patients before and after nonsurgical periodontal therapy, with and without local metronidazole administration, were first examined for the AST enzyme levels in GCF and then evaluated for microbiological and clinical variables. In each patient, 4 sites (one site/quadrant) with a probing depth of > or = 5 mm were selected and treated with separate treatment protocols. Certain microbial species including Prevotella intermedia, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans(A. a.) were found more often and/or in higher levels in AST active sites (36/40 first measurement--9/36 second measurement), while other species (Streptococcus and Actinomyces) were found more often and/or in higher levels in AST inactive sites (4/40 first measurement--8/36 second measurement). Eight post-treatment AST active sites revealed 1.5 mm of attachment loss, whereas 8 post-treatment AST inactive sites showed 1.37 mm of attachment gain. AST activity and microbiological-clinical data presenting such an agreement suggests that, AST level assessment would be beneficial as an adjunctive method alongside other clinical criteria, in guiding the clinician in periodontal treatment.

A clinical and microbiological evaluation of systemic and local metronidazole delivery in early onset periodontitis patients

The present study describes selected clinical and microbiological results obtained by treatment with local (Elyzol) and systemic (Flagyl) use of metronidazole alone and/or mechanical subgingival debridement in early onset periodontitis (EOP). Twelve patients, with lesions not distributed as in classical localized juvenile periodontitis, were included. They were randomly divided into local and systemic treatment groups each comprising 6 individuals, in each of whom 4 sites (one site/quadrant) with a probing depth of > or = 5 mm were selected and treated with separate treatment modalities. The overall treatment design provided 6 different test groups. Groups of quadrants received 1) scaling and root planing 2) local metronidazole treatment 3) systemic metronidazole treatment 4) local metronidazole combined with scaling and root planing 5) systemic metronidazole combined with scaling and root planing 6) No treatment. The microbiological and clinical effects of treatment modalities were monitored over 42 days. The results demonstrated reductions in mean counts of obligate anaerobic and capnophilic microorganisms coupled with significant improvements in mean clinical measurements (gingivitis, probing depth, attachment level) in all groups, except the untreated. Scaling and root planing provided an initial clinical improvement with a selective reduction of periodontopathogens (92.6% obligate anaerobes, 42.9% capnophilic microorganisms), whereas the combination of local or systemic metronidazole with scaling and root planing were found superior in reducing capnophilic bacteria (93.7% and 93.4%, respectively). It is of critical importance to have a treatment rationale for EOP, since bacterial differences exist in the etiological subforms of periodontitis. Microbial testing may be justified before prescribing the adjunctive antibiotic and selecting the mode of delivery for the successful clinical management of EOP.

Stability under vacuum of silicon trap detectors and their use as transfer instruments in cryogenic radiometry

The stability of the responsivity of trap detectors under vacuum has been studied by means of a special chamber designed for the test of photodetectors at low pressure. The first experiments at a wavelength of 647 nm show that the responsivity variations are smaller than the uncertainties of the measurements, approximately 3 parts in 10(5), when the detector operates successively in air, under vacuum, and then again in air. Calculations based on experiments with single windowless photodiodes indicate that the change in trap responsivity that is due to vacuum effects should be smaller than 1 part in 10(5), at least in the visible part of the wavelength range. This stability makes trap detectors suitable for cryogenic radiometry when one uses transfer detectors under vacuum.

Cytomegalovirus infection-enhanced chronic kidney allograft rejection is linked with intercellular adhesion molecule-1 expression

In human kidney allografts, association of acute rejection and glomerulopathy with cytomegalovirus (CMV) infection has been demonstrated. To investigate the effect of CMV infection on the development of experimental chronic kidney allograft rejection, heterotopic kidney allografts from DA (Ag-B4, RT1a1) rat donors to WF (Ag-B2, RT1u) rat recipients were used. The animals received cyclosporine A (CsA) 5 mg/kg/day s.c. either for 1 or 12 weeks. Two groups of recipients were infected with 10(5) plaque-forming units of rat CMV (RCMV) and two other groups were left noninfected and used as controls. The grafts were removed 12 weeks after transplantation for histology and immunohistochemistry. RCMV infection significantly enhanced the development of chronic kidney allograft rejection in rats on continuous CsA the intensity of interstitial inflammation (P < 0.025), particularly the degree of pyroninophilic cells in the inflammatory infiltrate (P < 0.025), the glomerular mesangial matrix increase (P < 0.05) and capillary basement membrane thickening (P < 0.01), the extent of endothelial cell swelling (P < 0.025) and intimal proliferation (P < 0.025) in the graft vasculature, and the extent of tubular epithelial atrophy (P < 0.025). Chronic allograft damage index (CADI) was significantly increased to 4.3 +/- 0.8 in RCMV-infected allografts, compared to 0.8 +/- 0.4 in noninfected (P < 0.02). In addition, RCMV infection significantly increased the number of acute rejection episodes (serum creatinine > 200 mumol/liter, P < 0.05) and almost doubled the end-stage serum creatinine. RCMV infection significantly increased ICAM-1 expression on the vascular endothelium (P < 0.05) and tubular epithelial cells (P < 0.01), and was linked with enhanced interstitial, glomerular, and tubular inflammation. In 80% of allografts on continuous CsA, RCMV antigens could be observed in sporadic inflammatory cells one week after infection and in tubular epithelial cells at 12 weeks. In heavily inflamed allografts where the CsA treatment was discontinued at one week, enhancement of RCMV infection on the histological changes attributable to chronic kidney allograft rejection could not be demonstrated. Our results show that during CsA immunosuppression, RCMV infection enhances chronic kidney allograft rejection associated with increased interstitial inflammation as well as vascular endothelial and tubular epithelial ICAM-1 expression.

A regenerative approach to the treatment of severe osseous defects: report of an early onset periodontitis case

The biological principles of guided tissue regeneration (GTR) and graft materials have become widely used as methods for the treatment of severe osseous defects. An early-onset periodontitis case which includes a 3-year follow-up is presented in this case report, which demonstrates the successful use of an expanded polytetrafluoroethylene barrier membrane (ePTFE; Goretex Periodontal Material) in conjunction with natural coral bone graft (Biocoral 450). The results after 3 years illustrate the potential for regenerative periodontal therapy in combination with appropriate prosthetic procedures where limited success might have been expected.

Rat cytomegalovirus infection and chronic kidney allograft rejection

To investigate the effect of cytomegalovirus (CMV) infection on the development of experimental chronic kidney allograft rejection, orthotopic kidney allografts from DA donors (Ag-B4, RT1a1) to WF (Ag-B2, RT1u) recipients were used. The rats received cyclosporine A (CsA) for 12 weeks. A group of recipients was infected with 10(5) plaque-forming units of rat CMV (RCMV), and another group was left non-infected and used as controls. The grafts were removed 12 weeks after transplantation. RCMV infection significantly enhanced the development of chronic kidney allograft rejection as follows: the intensity of interstitial inflammation (P < 0.025), particularly the degree of pyroninophilic cells in the inflammatory infiltrate (P < 0.025); the glomeruli mesangial matrix increase (P < 0.05) and capillary basement membrane thickening (P < 0.01); the extent of endothelial cell swelling (P < 0.025) and intimal proliferation (P < 0.025) in the graft vasculature; and the extent of tubular epithelial atrophy (P < 0.025). The chronic allograft damage index (CADI) was significantly increased to 4.2 +/- 0.9 in RCMV-infected allografts, compared with 0.8 +/- 0.4 in non-infected (P < 0.02). At the molecular level, RCMV infection significantly increased vascular endothelial (P < 0.05) and tubular epithelial (P < 0.01) ICAM-1 expression. Viral antigens were detected in tubular epithelial cells and in some inflammatory cells.

Evolution of glomerular basement membrane changes in chronic rejection

We have investigated the evolution of chronic glomerular changes in the absence of the recurrence of original disease in an experimental rat model of chronic renal allograft rejection. Using serial graft needle biopsies and serum creatinine levels, we were able to focus on early glomerular changes that are associated with good graft function. The recipient rats were divided into 5 groups, 2 with allogeneic (DA to WF) transplants and 3 with syngeneic (DA to DA) transplants. In the first 2 allogeneic groups, one group received cyclosporine (CsA) for 2 weeks (n = 7) and the other received CsA for 12 weeks (n = 5). In the 2-week treatment group, all allografts developed chronic rejection, compared with none in the 12-week group. Syngeneic controls received CsA for 2 (n = 3) and 12 weeks (n = 3), or no immunosuppression (n = 2) in order to exclude the effects of CsA. The first detectable ultrastructural event was slight deposition of electron lucent material in the glomerular basement membrane. Contrary to previous morphological studies, the initial deposition was not subendothelial, but was within the lamina densa itself. Examination of allogeneic grafts with good graft function and syngeneic grafts showed glomerular alterations that were similar to the early changes preceding chronic rejection. The intensity of changes in optimally immunosuppressed allografts was mild, and they were arrested early in the evolving stage of glomerular basement membrane changes. In the suboptimally immunosuppressed allografts with chronic rejection, the glomerular basement membrane changes became more pronounced and extensive in subsequent biopsies. Thus, all recipients in different groups showed similar glomerular alterations, but to different intensities. These results suggest a common pathogenetic mechanism which might be endothelial damage. In chronic rejection, the endothelial damage might be immunologically mediated by rejection episodes and progressive, whereas in syngeneic grafts and in allografts without chronic rejection, perioperative trauma, ischemia, and graft reperfusion may be responsible for the self-limiting glomerular changes.

Mycophenolate mofetil (MMF, RS-61443) inhibits inflammation and smooth muscle cell proliferation in rat aortic allografts

To investigate the impact of mycophenolate mofetil (MMF) on allograft arteriosclerosis (chronic rejection) in rat aortic allograft model, we administrated MMF 20 mg/kg/day from the day of transplantation and sacrificed the rats at 1-12 months afterwards. MMF significantly suppressed all major histological manifestations of allograft arteriosclerosis, i.e. adventitial inflammation, media necrosis and intimal thickening and cellularity. There was a significant decrease in the replication rate (3H-thymidine incorporation) of inflammatory cells in the adventitia and of smooth muscle cells (SMC) in the media. MMF did not have any major effect on mRNA expression of several growth factors, (determined by polymerase chain reaction with inbuilt glyceraldehyde-3-phosphate dehydrogenase control), which have previously been demonstrated to be elevated in nonimmunosuppressed allografts. Immunoperoxidase staining showed a 40% reduction in the number of adventitial interleukin-2 receptors expressing lymphoid cells in MMF-treated allografts. The intensity of SMC alpha-actin staining was also significantly reduced. As the results suggested that MMF may have a direct antiproliferative effect on SMC, this possibility was investigated in primary SMC cultures in vitro and using the carotid denudation model in vivo. Both approaches showed inhibition of SMC proliferation by MMF. Our results indicate that MMF inhibits histopathological changes of chronic rejection by reducing the immune response and possible replication of SMC.

Generation of a Ni(II) binding site by introduction of a histidine cluster in the structure of human glutathione transferase A1-1

Two mutant forms of human glutathione transferase (GST) A1-1 with affinity for metal ions were constructed by introduction of His residues by site-directed mutagenesis. A mutant, 2-His, contained the mutations Lys84Gln, Asp85His and Glu88His, and another, 5-His, contained the mutations Tyr79His, Asn80His, Lys84His, Asp85His and Glu88His. The mutant proteins were obtained in good yields (40-150 mg per 3 l culture) by heterologous expression in Escherichia coli. The mutant enzymes possessed novel binding affinities for Ni(II) and Zn(II) ions, as demonstrated by immobilized metal ion affinity chromatography. The mutant with two novel His residues (2-His mutant) did not bind as tightly to immobilized Ni(II) as did the mutant with five novel His residues (5-His mutant). When tested for affinity to immobilized Zn(II), only the 5-His mutant remained bound to the column. The affinity of the 5-His mutant for Ni(II) ions in solution was determined by binding experiments in an aqueous polymeric two-phase system. Analysis of the binding curve showed two binding sites per enzyme subunit and a dissociation constant of 6.7 +/- 1.6 mu M. The kinetic constants kcat, Km and kcat/Km for the reaction with glutathione and 1-chloro-2,4-dinitrobenzene were determined by steady-state kinetic analysis and the parameter values for the mutant forms were found to be indistinguishable from those obtained for the wild-type GST A1-1. The differences in surface charge in the mutant proteins as compared with the wild-type enzyme did not alter the pH dependence of kcat. The results provide an alternative method for purification of fully active recombinant GST A1-1 by the introduction of novel metal binding sites. The data also showed that two His residues are sufficient for Ni(II) binding.

Stabile D-peptide analog of insulin-like growth factor-1 inhibits smooth muscle cell proliferation after carotid ballooning injury in the rat

Restenosis after angioplasty is believed to result from stimulation of smooth muscle cells (SMC) by various growth-promoting factors as a consequence of endothelial injury. In this study we have tested the hypothesis that insulin-like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) interaction is a rate-limiting step for SMC replication by blocking this interaction with a synthetic D-amino acid peptide structurally resembling the D-domain of IGF-1. After rat carotid artery denudation, semiquantitative PCR analysis demonstrated a significant elevation of IGF-1, platelet-derived growth factor B, transforming growth factor beta 1, and epidermal growth factor mRNAs 10 days after endothelial injury, concomitantly with the induction of intimal SMC proliferation and intimal thickening. Administration of 10-30 micrograms.kg-1.day-1 of D-analog of IGF-1, devoid of proteolytic degradation in body fluids, reduced intimal SMC replication by 60-70%. The peptide also inhibited [3H]TdR incorporation and [3H]glycine incorporation in cultured SMCs by 60-80%, whereas a "scrambled" control peptide consisting of the same amino acids had no effect. The results suggest that IGF-1/IGF-1R interaction is a rate-limiting step for SMC replication. Blocking of this interaction with stabile D-peptide analog of IGF-1 at the level of IGF-1R may offer an entirely new approach for the prophylaxis and treatment of restenosis after cardiac revascularization procedures.

Congenital ocular motor apraxia in two siblings

Two siblings whose features met Cogan's classic description of congenital ocular motor apraxia were examined. There was first-degree consanguinity in the family. Each had an absence of voluntary and optically-induced horizontal eye movements and demonstrated classic head thrusting.

Duodenal phytobezoar: a case report and review of the literature

Phytobezoars are an unusual cause of small bowel obstruction. We report a case of small bowel obstruction due to phytobezoar in a 63 year-old female patient who had undergone gastric surgery (truncal vagotomy with pyloroplasty) for duodenal ulcer disease complicated by gastric outlet obstruction 10 years ago. We diagnosed this bezoar case by radiologic methods and these methods keep their importance for the diagnosis of small bowel obstruction with phytobezoars.

Chronic renal allograft rejection can be predicted by area under the serum creatinine versus time curve (AUCCr)

Acute rejection is the most important single risk factor for chronic renal allograft rejection. Numerical quantitation of rejection episodes does not take into account the intensity and length of these episodes, both of which may contribute to the severity of chronic rejection. We propose a single numerical parameter for the frequency, intensity and length of acute rejections, the "Area Under the Serum Creatinine versus Time Curve" (AUCCr) using renal allografts between inbred rat strains. Twenty-seven renal transplantations were performed from the DA to WF rat strain. The rats were immunosuppressed with 5 mg/kg body weight of CyA injected s.c. for 1, 2, 3 and 12 weeks, resulting in differing numbers (0-4) of biopsy-confirmed acute rejections of varying intensity (s-cre: 100-448 mumol/L) and length (3-24 days), all of which were reversed with additional CyA treatment. The intensity of chronic changes in graft histology was quantitated using the "Chronic Allograft Damage Index" (CADI). End-point transplant function was quantitated as level of serum creatinine at sacrifice. The AUCCr from 0 to 3 weeks (AUCCr0-3), encompassing the recovery period after operation, free of rejections, did not correlate with the CADI (r = 0.230, P = 0.249). All AUCCr from 3 weeks onwards correlated with the CADI. The best correlation with the CADI was obtained with AUCCr from 3 to 12 weeks (AUCCr3-12) (r = 0.922, P = 0.0001). This interval coincides with the timing of all acute rejection episodes. AUCCr3-12 correlated equally well to end-point transplant function (r = 0.890, P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

A small supernumerary marker chromosome X identified by in situ hybridization

Cytogenetic analysis of a girl with moderate mental retardation and dysmorphic features revealed a 46,XX/47,XX,+mar karyotype. Fluorescence in situ hybridization using chromosome specific alpha satellite probes showed that the supernumerary marker originated from the X chromosome. To our knowledge, this is the first reported case of a female patient mosaic for a supernumerary small marker chromosome derived from X, and hence mosaic for trisomy of the pericentric region of the X chromosome.

Phase-shift interference microscope for the investigation of dipole-orientation distributions

A compact experimental setup for an electro-optical microscope is introduced. The microscope is based on phase-shift interferometry (a well-known tool for surface profilometry) that is modified for measuring electrooptic responses. Its feasibility is demonstrated with a two-dimensional map of the electro-optic activity of a periodically poled nonlinear-optical side-chain polymer.

Involvement of sulfhydryl groups in the stable fluorescent derivatization of proteins by o-phthalaldehyde

Treatment of human alpha-1-proteinase inhibitor (alpha-1-PI) with o-phthalaldehyde (OPA) at pH 8.0 and 25 degrees C, in the absence of added thiol resulted in the formation of a mixed population of fluorescent and non-fluorescent isoindoles. The stoichiometry of isoindole formation was tentatively calculated to be 6:1 for unreduced alpha-1-PI and 10:1 for inhibitor treated with dithioerythritol, implicating not only cysteine but also non-sulfur nucleophilic centres as reaction partners. Despite the apparent involvement of the single cysteine residue in alpha-1-PI in the over-all derivatization process, the extent of fluorescent derivatization was independent of the redox state of the inhibitor. Hence the fluorescing moiety was not a 1-alkylthio-2-alkyl-substituted isoindole, as generally observed. The finding that isoindole formation in proteins is not limited by sulfhydryl content and that fluorescent products may originate from amino acid(s) other than cysteine cautions against interpreting fluorescent derivatization by OPA as evidence for cross-linking of lysine to cysteine residues.

Pilomatrixoma of the earlobe

BACKGROUND

Pilomatrixoma most commonly occurs in the head and neck region, appearing primarily in the first two decades of life. The lesion is described as a tumor with differentiation toward hair cells and surgical excision is the treatment of choice.

OBJECTIVE

We report an uncommon localization of a perforating type pilomatrixoma of 5 x 4 x 4 cm in size that developed from the earlobe.

METHODS

Histopathological examination revealed pilomatrixoma. Total resection of the tumor was performed. The earlobe was reconstructed by forming a posterior-superior pedicled skin flap.

RESULTS

No recurrence was observed and a good cosmetic result was obtained.

CONCLUSION

Local recurrence does not generally occur if the tumor is completely removed. The case we present is of interest in having a history of trauma to the region and a relatively rapid growth with perforation of the overlying skin.

Chronic allograft rejection: an update

The aetiology of chronic rejection is most likely multifactorial. The common feature in all organ allografts undergoing chronic rejection is persistent perivascular inflammation and a concentric generalised arteriosclerosis affecting all first and second order intramural arteries. A hypothesis is presented that low-grade damage to the endothelium induces the secretion of growth factors which, in turn, are responsible for smooth muscle cell replication and their influx into intima.

Cytomegalovirus infection-enhanced allograft arteriosclerosis is prevented by DHPG prophylaxis in the rat

BACKGROUND

Major risk factors for accelerated allograft arteriosclerosis include humoral and cellular immune response, hyperlipidemia, and viral infections. We demonstrated earlier that rat cytomegalovirus (RCMV) infection doubles smooth muscle cell proliferation and intimal thickening of rat aortic allografts. In this study, the effects of 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG) on RCMV-enhanced rat allograft arteriosclerosis are investigated.

METHODS AND RESULTS

Aortic allografts from the DA to the WF rat strain were used. The recipients were inoculated with 10(5) plaque-forming units of RCMV 1 day after transplantation. Two groups of RCMV-infected rats were treated with DHPG with an initial dose of 20 mg/kg IP and a maintenance dose of 10 mg/kg IP twice a day for a period of 14 days. In the DHPG prophylaxis group (n = 22), the drug administration started 1 day before infection, and in the DHPG treatment group (n = 17), 7 days after infection. One group of infected rats was left untreated (n = 21). The grafts were removed 7 and 14 days and 1, 3, and 6 months after transplantation. In the DHPG prophylaxis group, no virus could be recovered by plaque assays. In the treatment group, 50% of rats were virus-positive at 1 month and 40% at 3 months. DHPG prophylaxis prevented the infiltration of inflammatory cells and their proliferation in the adventitia of RCMV-infected recipients (P < .01), with a 60% reduction in the interleukin-2 receptor expression (P < .05) and a 30% decrease in major histocompatibility complex class II expression (P = NS). DHPG prophylaxis did not significantly alter the levels of insulin-like growth factor-1, epidermal growth factor, platelet-derived growth factor-BB, transforming growth factor-beta 1, acidic fibroblast growth factor, and basic fibroblast growth factor messages in the allograft vascular wall. Early media necrosis was reduced. Arteriosclerotic alterations and proliferation of smooth muscle cells were both reduced 50% to 70% by DHPG prophylaxis (P < .05 at 3 months). The responses in the DHPG treatment group were quite similar but less impressive and statistically nonsignificant.

CONCLUSIONS

We consider it likely that DHPG inhibits arteriosclerotic alterations primarily by reducing the infectious virus and thereby the inflammatory response in the allograft vascular wall; another possibility is a direct antiproliferative effect on smooth muscle cell replication. A dose-dependent inhibitory effect of DHPG on smooth muscle cell replication was recorded in an in vitro study.

The evolution of clinical periodontal therapy

Periodontal diseases are considered as old as the history of mankind, Magical, religious and herbal treatments were demonstrated in almost all of the early writings. However, methodical, carefully reasoned therapeutic approaches did not exist until the middle-ages and modern treatment with a scientific base and sophisticated instrumentation did not develop until the 18th century. Prior to the 1950s, diseases were mostly treated by root debridement and the extraction of the affected teeth. Until the 1970s, it was primarily the symptoms of periodontal diseases that were treated. The goal was radical elimination of the periodontal pocket (resective therapy). The means were gingivectomy, flap procedures and osseous surgery. The disadvantages were the massive sacrifice of periodontal tissues, lack of regeneration and clinically elongated teeth. These disadvantages, along with the realization of the importance of aetiologic agents, raised questions about the necessity of total pocket elimination, and the control of subgingival infection by a thorough scaling and root planing (nonsurgical therapy), with and without antibiotics, became a commonly used treatment during the 1980s. Comparative longitudinal studies, surgical versus nonsurgical, demonstrated that both surgical and nonsurgical therapy result in limited regeneration and healing with a long junctional epithelium. The most important aspects of today's modern concept of periodontal therapy are causal, regenerative, and specific for disease type and severity. Although the regeneration of the periodontium can be accomplished with the biological principles of guided tissue regeneration and graft materials, compared to conventional methods, the restoration of a completely normal periodontal status has not yet been achieved. We are about to reach our ultimate goals and presently, the more promising research directions for a substantial regeneration seems to lie in biological mediators. Although the future of periodontal therapy is bright, it is still of critical importance to have a preventive strategy to keep individuals healthy beforehand.

The ultrastructural examination of gingival fibromatosis

Hereditary gingival fibromatosis (GF) is a special type of fibrous overgrowth classified as non-inflammatory gingival enlargement. Microscopically, the connective tissue consists of coarse collagen bundles and fibroblasts. The ultrastructural examination of fibrous gingival hyperplasia reveals that fibroblasts phagocyte the mast cell granules and mast cells stimulate collagen synthesis which results in hyperplasia. In the ultrastructural examination of phenytoin-induced hyperplasia, fibroblasts, phagocytosing mast cell granules were also found. Based on these findings, the purpose of this study is to establish whether there is a relationship between fibroblasts and mast cells in GF. The gingival tissues of 5 patients with GF were examined ultrastructurally. In the connective tissue, well-defined bundles of collagen fibres were found together with fibroblasts and capillaries. There were mast cells around these capillaries which had collapsed lumens. The proximity of the mast cells and fibroblasts may indicate that mast cells play some role on collagen synthesis of fibroblasts.

Widening the zone of peri-implant attached gingiva

The use of implant systems is a focus of interest nowadays, as an alternative method to classical dental prostheses used in partially or completely edentulous patients. Such an interest of both the patients and the clinicians seemed likely to be due to the opportunity of using fixed prostheses on these implants. However, besides its advantages, problems exist regarding the zone of attached gingiva around implants, for the vestibular depth has generally been decreased because of the excessive amount of alveolar bone resorption. The problem from the periodontal point of view is that the periodontal pockets around implants used as abutments may turn out to be pathologic pockets and an inadequate and nonfunctional vestibular depth will result. In this study, the conventional free soft tissue autograft technique was performed around 34 implants in 9 patients in whom 40 Brånemark implants in total were placed. The postoperative evaluations indicated that the decrease in the vestibular depth, due to the shrinkage of the keratinized tissue had a negative effect on this surgical procedure. The use of acrylic stents after surgery seemed to be a better solution and would give good clinical results.

Partial inhibition of allograft arteriosclerosis (chronic rejection) by 15-deoxyspergualin

15-deoxyspergualin (DSG) is an immunosuppressive drug that suppresses monocyte/macrophage function and/or T cell induction and early differentiation of B lymphocytes. It is as effective as cyclosporine in the prevention of acute rejection. We have investigated the effects of DSG on rat aortic allograft arteriosclerosis (chronic rejection). DSG was administered to the recipient rat at a dose of 0.3-10 mg/kg/day i.p. for 1-3 months, after which recipients were sacrificed. Histological changes were quantitated from paraffin sections. DSG is effective in chronic rejection in rat aortic allografts and reduces all three manifestations in the vascular wall--adventitial inflammation, media necrosis, and intimal thickening. At the dose of 1.0 mg/kg/day we demonstrated significant inhibition of adventitial inflammation from 10.6 point score units (psu) to 4.7 psu (P < 0.05), of media necrosis (P = 0.004) and of intimal thickening from 2.9 psu to 0.8 psu (P = 0.008). The therapeutic window was small in the long-term experiment. Doses of 3-10 mg/kg/day were toxic and 0.3 mg/kg/day was ineffective. In vitro smooth muscle cell proliferation was not inhibited by DSG and in the in vivo carotic denudation model DSG had no inhibitory effects either. These results suggest that DSG works via suppression of the immune/inflammatory response rather than via a direct antiproliferative effect on smooth muscle cells.

The impact of acute episodes of rejection on the generation of chronic rejection in rat renal allografts

We have investigated the impact of the frequency of acute rejection episodes on the generation of chronic rejection in long-surviving rat renal allografts. A total of 33 renal transplantations was performed from DA to WF rats, receiving different cyclosporine-based immunosuppressive regimens. As a consequence, different numbers of acute rejection episodes were recorded in the recipients, all of which were successfully treated with cyclosporine. Upon sacrifice at 12 weeks posttransplantation, the frequency of acute rejection episodes was correlated with the major histological parameters of chronic rejection and with graft function. The intensity of the major histological parameters of chronic rejection, exemplified by vascular intimal proliferation and glomerular mesangial matrix increase, and the decline in graft function between the no-rejection vs. rejection groups, were directly proportional to the number of acute rejection episodes. Vascular intimal proliferation increased from 0.5 +/- 0.4 (arbitrary units) in the no-rejection group to 1.7 +/- 0.9 (P = 0.0093) after one rejection episode, to 2.2 +/- 0.3 (P = 0.0001) after two, and to 2.2 +/- 0.5 (P = 0.0014) after three or four rejection episodes. Glomerular mesangial matrix increased from 1.2 +/- 0.3 (arbitrary units) in the no-rejection group to 1.9 +/- 0.6 (P = 0.017) after one, to 2.2 +/- 0.5 (P = 0.0005) after two, and to 2.1 +/- 0.4 (P = 0.003) after three or four rejection episodes. Serum creatinine increased from 93 +/- 24 mumol/L in the no-rejection group to 196 +/- 92 mumol/L (P = 0.016) after one, to 238 +/- 38 mumol/L (P = 0.0001) after two, and to 308 +/- 85 mumol/L (P = 0.0016) after three or four rejection episodes. Prolongation of the preoperative ischemia time from 30-60 min correlated with an increase in the number of acute rejection episodes as well as an increase in chronic changes. To conclude, in the rat renal allograft model, acute allograft rejection carries a highly significant correlation with the development of chronic rejection.

The effect of cyclosporin-A on the ultrastructure of gingival tissue in Behçet's disease

Autoimmune processes are said to play an active role in aetiology of Behçet's disease (BD), which is also known as a multisystem disease. In the treatment of this autoimmune disease, cyclosporin A (CyA) is used. Gingival hyperplasia (GH) is one of the important side effects that have been observed in some of the patients. We aimed to evaluate the CyA-induced gingival hyperplasia in BD patients. There were 3 study groups, each having 5 patients. In the first group displaying GH, mast cells were located between epithelial cells and in the connective tissue. Mast cell granules were in crystalline form and electron-dense cored form. Fibroblasts and plasma cells were present in the connective tissue. The second group did not display GH and the mast cells were similar to those in the first group. The third group, was the control group, in which the mast cells were located between the epithelial cells and connective tissue. Mast cell granules were in electron-dense cored form. We concluded that the development of CyA-induced gingival hyperplasia is determined mainly by individual sensitivity to CyA, because although both test groups which received CyA showed an increased number and activity of fibroblasts, only one group of patients developed GH.

A genetic and dermatoglyphic study on periodontitis

Periodontal diseases encompass a wide range of disease manifestations and processes from the mildest inflammation of gingiva to the most advanced destructive periodontitis with loss of attachment, bone tissue and teeth. No entirely satisfactory identification and classification exist in periodontitis especially for high risk early onset periodontitis (EOP) cases, because of insufficient knowledge about the aetiological and host factors and their overlapping clinical and laboratory features. In this study, the dermatoglyphics, which is a genetic test method, suggesting the modes of inheritances of hereditary diseases, was performed on 36 EOP and 20 adult periodontitis (AP) patients and 20 periodontally healthy individuals. The diagnostic value of this genetic test method, which is the study of the quantitative and qualitative characteristics of patterns of ridged skin, and the role of heredity on periodontal diseases are discussed.

Clinical studies on juvenile, rapidly progressive and adult periodontitis before and after periodontal therapy (I)

The sample in the present study comprised 36 patients who were referred for treatment of periodontal disease. Twenty-four of them were early onset periodontitis (EOP) patients and 12 were adult periodontitis (AP) patients. Based upon the age, number of involved teeth and the location of diseased sites, the EOP patients were divided into two groups as juvenile periodontitis (JP) and rapidly progressive periodontitis (RPP). All the patients were individually examined both clinically and radiographically. At a baseline examination and 3 months after active therapy, the patients were evaluated for plaque, gingivitis, probing depths and probing attachment levels. Following instruction in proper oral hygiene measures, all of the patients were subjected to periodontal treatment. Treatment comprised scaling and root-planing, occlusal adjustment, tetracycline administration and periodontal surgery with osteoplasty. Results showed that age limits between JP and RPP cannot be drawn with certainty. The mean age for the JP group was 21.83 years and was 30.58 years for the RPP group. The number of involved teeth was found to increase with age. The first molars were the most frequently affected teeth followed by the incisors. Three months after active treatment, the response of periodontal tissues to therapy both in EOP and AP groups was almost identical.

Towards understanding the pathophysiology of chronic rejection

Chronic allograft rejection is the major reason why allografts are lost. While only 2%-3% of all allografts are lost during the first year to irreversible acute rejection, approximately 6%-7% are lost during each subsequent year to chronic rejection. The major manifestation of chronic rejection in all organs is persistent perivascular inflammation and allograft arteriosclerosis. Bearing this in mind, we have developed a model to investigate the pathophysiology of allograft arteriosclerosis using aortic transplantations between inbred rat strains. The results obtained thus far indicate that several different inflammatory cascades are operative within the vascular wall during allograft arteriosclerosis. The relative importance of these different cascades, and particularly the role of growth factors as final effectors, has not yet been defined. Attempts to suppress allograft arteriosclerosis under experimental conditions have already met with some success: under conditions where no immunosuppression is provided we have been able to delay the process by at least 3 months, though we have not been able to block it indefinitely. It may be expected, however, that once the inflammatory cascades leading to smooth muscle cell replication in the allograft media and their influx into the intima are better defined, more specific approaches to the inhibition of allograft arteriosclerosis will be developed.

Diagnostic studies on juvenile, rapidly progressive and adult periodontitis before and after periodontal therapy (II)

The use of antibody levels may identify subjects developing destructive periodontitis or provide markers of disease type. Clinical parameters can be used to group cases but they are incapable of detecting differences in host-susceptibility and host immune response. The validity of radial immunodiffusion (RID) as a laboratory screening method in diagnosis based on antibody quantitation has been evaluated in 36 patients before and after periodontal therapy. It was concluded that the serum IgA, IgG, IgM and parotid IgA concentration profiles, measured with RID have little value in determining the subgroups of early onset periodontitis patients but they can be used to differentiate these groups from slowly progressing adult periodontitis patients.