Evidence for diversity within Propionibacterium acnes: a comparison of the T-cell stimulatory activity of isolates from inflammatory acne, endocarditis and the laboratory

BACKGROUND: Propionibacterium acnes is primarily associated with the pathogenesis of acne vulgaris but reports are increasing in number implicating P. acnes in other diseases such as abscess formation, meningitis and endocarditis. The pathogenicity of P. acnes is thought to be partly due to the interaction of the bacterium with the immune system. Historically, investigations have focused on humoral and cell-mediated immune responses to P. acnes antigens without attention to the possibility that different antigens may be expressed by different isolates. OBJECTIVE: Investigations were performed to determine whether there were differences between a laboratory strain of P. acnes (P-37) and fresh clinical isolates in their ability to stimulate naive and adult lymphocytes. MATERIAL AND METHODS: The fresh isolates were collected from a patient with inflammatory acne and a patient with P. acnes-induced prosthetic valve endocarditis. The lymphocyte transformation assay was used to detect responses to whole-cell suspensions of stationary phase P. acnes isolates during 7 days of incubation. RESULTS: The acne isolate was significantly more stimulatory for cord blood mononuclear cells (CBMNCs) than the laboratory isolate (P. acnes P-37) at day 4 of incubation. There were no significant differences between the three strains at any other time points. However, the isolate cultivated from inflammatory acne was significantly more stimulatory for peripheral blood mononuclear cells (PBMNCs) from acne donors than the endocarditis isolate or the laboratory strain at most time points. There were no significant differences between the endocarditis strain and the laboratory strain. CONCLUSION: It can be hypothesized that in case of P. acnes-induced endocarditis lymphocyte stimulation is a disadvantage for the microorganism and therefore a lack of lymphocyte stimulation may be relevant to the pathogenesis of endocarditis.     

Population-based study of glutathione S-transferase mu gene deletion in adult glioma cases and controls

Gene deletion at the glutathione S-transferase mu locus (GSTM1) has previously been associated with increased risk for environmentally- induced cancers (e.g. smoking-related lung cancer). In the present study we examined the hypothesis that GSTM1 deletion is a risk factor for malignant brain tumors in adults. We compared the prevalence of the GSTM1 homozygous deletion polymorphism in 158 Caucasian adults with gliomas with 157 controls. Cases and controls were drawn from a large population-based case-control study of brain cancers in six San Francisco Bay area counties. Overall, the prevalence of the GSTM1 deletion was similar in cases (83/158; 53%) and controls (78/157; 50%). Among brain tumor cases, analysis of variance modeling indicated a significant interaction of GSTM1 genotype and gender associated with age at diagnosis (P = 0.02). This effect was due to the fact that women with GSTM1 deletion were younger on average at diagnosis than women who were GSTM1 positive (43.9 years versus 52.4 years, respectively). Age at diagnosis among men was similar for those who were GSTM1 deleted and GSTM1 positive (49.4 years and 47.2 years, respectively). The younger age at diagnosis of GSTM1 null female cases compared with GSTM1 positive cases was observed in astrocytoma as well as the higher grade tumors (e.g. glioblastoma multiforme). There was no association of GSTM1 deletion with age or gender in controls. These studies suggest that among female cases, GSTM1 deletion may be associated with earlier age at onset. Confirmation of these findings could provide important clues to gene-environment interactions in the etiology of malignant brain tumors.      

Visibility of dental pulp spaces in dental ultrasound

The purpose of this study was to assess the feasibility of dental ultrasound with conventional sonographic equipment. The teeth of three adult volunteers who had cone beam CT examinations performed previously with clinical indications and one extracted tooth were examined using linear and compact (hockey stick) sonographic probes. The sonographic images were compared with cone beam CT images reconstructed accordingly. Dental pulp spaces were demonstrated in all teeth not covered with prosthetic crowns. The dentin and pulp were best visualized at the level of the neck of the teeth. The dentin was hypoechoic, and the superficial layer comprising the cementum and the pulp spaces were hyperechoic. Dental ultrasound is feasible with general purpose sonographic machines. The buccal surfaces of all teeth are accessible with a compact (hockey stick) probe. Visualization and differentiation of dental pulp spaces, dentin and the superficial layer comprising cementum is possible in the portions of teeth not covered by the alveolar bone or prosthetic crowns. The dental pulp spaces are best seen at the level of the tooth neck. Pulp and endodontic fillings can be distinguished on ultrasound.     

Posttransplant T-cell lymphoproliferative disorders--an aggressive, late complication of solid-organ transplantation

T-cell non-Hodgkin's lymphomas are an uncommon occurrence after solid- organ transplantation. We describe a morphologically and immunophenotypically distinct group of T-cell lymphoproliferative disorders that occurred late in the course of six patients with solid- organ transplants. The patients ranged in age from 31 to 56 years (median, 43). Three were male; all were splenectomized. The interval from transplant to the diagnosis of lymphoma ranged from 4 to 26 years (median, 15). Symptoms at presentation were related to sites of involvement. Pulmonary, marrow, and CNS involvement were present in five, four, and one case, respectively. No patient had lymphadenopathy. Five patients had an elevated lactate dehydrogenase level (range, 226 to 4,880 IU/L; median, 1,220 IU/L). Five of six patients had a leukoerythroblastic reaction. All cases had large-cell histology and frequently contained cytoplasmic granules. Those cases tested expressed CD2, CD3, and CD8 and were negative for B-cell antigens. T-cell receptor beta- and gamma-chain genes were clonally rearranged in three of three and one of three cases, respectively. All T-cell posttransplant lymphoproliferative disorders (T-PTLDs) studied were negative for Epstein-Barr virus (EBV), human T-cell leukemia/lymphoma virus type 1 (HTLV-1), human T-cell leukemia/lymphoma virus type 2 (HTLV-2), and human herpes virus type 8 (HHV-8) genomes. Treatment with acyclovir (three patients) or chemotherapy (three patients) resulted in two responses. All patients had an aggressive course, with a median survival duration of 5 weeks. In conclusion, a clinically aggressive T- PTLD may be a late complication of solid-organ transplantation and does not appear to be related to EBV, HTLV-1, HTLV-2, or HHV-8 infection.     

Relation of psychological distress to the international normalized ratio in patients with venous thromboembolism with and without oral anticoagulant therapy

Summary. Background: Psychological distress might affect the international normalized ratio (INR), but effects might vary depending on oral anticoagulant (OAC) therapy. Objectives: To investigate the association of psychological distress with INR and clotting factors of the extrinsic pathway in patients with and without OAC therapy. Patients and methods: We studied 190 patients with a previous venous thromboembolism (VTE); 148 had discontinued OAC therapy and 42 had ongoing OAC therapy. To assess psychological distress, all patients completed validated questionnaires to measure symptoms of depression, anxiety, worrying, anger and hostility. INR, fibrinogen, factor (F)II:C, FV:C, FVII:C and FX:C were measured as part of outpatient thrombophilia work‐up. Results: In VTE patients without OAC therapy, the odds of a reduced INR (< 1.00) were significantly increased from 1.5 to 1.8 times for an increase of 1 standard deviation (SD) in symptoms of depression, anxiety, worrying and anger, respectively, after adjusting for gender, age, body mass index, socioeconomic status, hematocrit and C‐reactive protein. Worrying, anger and hostility also showed significant direct associations with FVII:C. In patients with OAC therapy, INR was unrelated to a negative affect; however, lower FVII:C related to anxiety and worrying as well as lower FX:C related to anger and hostility were observed in patients with OAC therapy compared with those without OAC therapy. Conclusions: Psychological distress was associated with a reduced INR in VTE patients without OAC therapy. The direction of the association between psychological distress and activity in some clotting factors of the extrinsic coagulation pathway might differ depending on whether VTE patients are under OAC therapy or not.