Oral application of a periodontal pathogen impacts SerpinE1 expression and pancreatic islet architecture in prediabetes.

BACKGROUND AND OBJECTIVES: Epidemiological studies suggest a close association between periodontitis and prediabetes/insulin resistance (IR) but whether periodontitis causes prediabetes in humans is not known. Using various animal models, we have recently established that periodontitis can be an initiator of prediabetes, which is characterized by glucose intolerance, hyperinsulinemia and IR. In addition, our in vitro studies indicated that Porphyromonas gingivalis (Pg) induced insulin secretion in MIN6 ß cells and this induction was in part SerpinE1 (plasminogen activator inhibitor 1, PAI1) dependent. However, the mechanism(s) by which periodontitis induces prediabetes is not known. As α and ß cells in pancreatic islets are the major modulators of glucose levels, we investigated whether experimental periodontitis by oral application of a periodontal pathogen caused molecular and/or cellular alterations in pancreatic islets and whether SerpinE1 was involved in this process. MATERIAL AND METHODS: We induced periodontitis in C57BL/6 mice by oral application of a periodontal pathogen, Pg, and determined changes that occurred in islets following 22 weeks of Pg application. Pancreatic islet architecture was determined by 2-D and 3-D immunofluorescence microscopy and SerpinE1 and its target, urokinase plasminogen activator (uPA), as well as insulin, glucagon and Pg/gingipain in islets were detected by immunofluorescence. The presence of apoptotic islet cells was determined by both histochemical and immunofluorescence TUNEL assays. To investigate further the direct effect of Pg on apoptosis and the involvement of SerpinE1 in this process, we used SerpinE1 knockdown and scrambled control clones of the MIN6 pancreatic ß-cell line. RESULTS: Pg/gingipain was detected in both the periodontium and pancreas in the experimental group. Islets from animals that were administered Pg orally (experimental group) developed significant changes in islet architecture, upregulation of SerpinE1, and increased ß-cell apoptosis compared with the control group. We also observed that exposure of MIN6 cells to Pg in vitro resulted in apoptosis. However, apoptosis was significantly reduced when SerpinE1 expression by MIN6 cells was knocked down. CONCLUSION: Oral application of the periodontal pathogen Pg to C57BL/6 mice induces periodontitis, translocation of Pg/gingipain to the pancreas and results in complex alterations in pancreatic islet morphology. SerpinE1 appears to be involved in this process.

Transforming growth factor beta1 gene expression during vaginal wound healing in a rabbit menopause model.

OBJECTIVE: Surgical outcome following reconstructive pelvic surgery is largely dependent on the vaginal wound healing process. As peri- and post-menopausal women are the most likely candidates to undergo these surgeries, it is important to understand the effect of estrogen deficiency on this process. Transforming growth factor beta (TGFß) is an important mediator of wound healing. We sought to assess TGFß1 gene expression during the vaginal incisional wound healing process in a rabbit menopause model. DESIGN: Animal study. SETTING: Animal laboratory. SAMPLE: Sixty-three rabbits were used for this study. METHODS: Twenty-one underwent bilateral oophorectomy, 21 underwent a sham surgery, and 21 served as controls. Eight weeks later, standardised full-thickness 6-mm diameter circular segments were excised from the vagina of all rabbits. Animals were killed sequentially, before wounding, and at 0, 4, 7, 14, 21 and 35 days after wounding, and the wounds were harvested. MAIN OUTCOME MEASURES: Wound closure and TGFß1 gene transcription, as measured by real-time polymerase chain reaction (PCR). RESULTS: Wound closure was significantly protracted (P < 0.02), whereas TGFß1 gene expression was significantly increased (P < 0.0001) during the wound healing process in oophorectomised rabbits, as compared with both control and sham groups. CONCLUSION: Oophorectomised rabbits show protracted incisional vaginal wound healing associated with increased TGFß1 gene transcription.

Secretion of bromide by the canine prostate.

Four dogs with surgically produced prostatic fistulas were given single oral doses of 1.13 gm of sodium bromide daily for five consecutive days. Two days later the mean (+/- SE) serum level of bromide was 28.0 +/- 4.0 meq/L and the serum chloride level had decreased from a pretreatment value of 112.5 +/- 1.0 meq/L to 86.5 +/- 3.7 meq/L; in the basal prostatic secretion, the mean prostatic fluid to serum (PF/S) ratios for bromide and chloride were 0.56 +/- 0.15 and 0.53 +/- 0.11, respectively, and were not different (P greater than 0.05, paired t-test); at higher rates of secretion provoked by intravenous pilocarpine the corresponding PF/S ratios of 1.48 +/- 0.04 and 1.32 +/- 0.01 were significantly different (P less than 0.05, paired t-test). It is concluded that the processes involved in forming the basal and pilocarpine-induced prostatic secretions must differ and that the ability of the chloride-transporting system to transport bromide is slightly greater than that for chloride. Because it may impair sperm motility, bromide secreted in prostatic fluid potentially could adversely affect reproduction.

Nontuberculous mycobacterial infection attributable to Mycobacterium intracellulare serotype 10 in two rhesus monkeys.

Infection with Mycobacterium intracellulare serotype 10 was diagnosed in 2 rhesus monkeys (Macaca mulatta) in a closed colony of 90 animals. The clinicopathologic presentation in 1 animal with advanced disease was characterized by a precipitous weight loss, therapeutically unresponsive diarrhea, anemia, weakness, prostration, refractory tuberculin tests (using mammalian old tuberculin and M bovis purified protein derivative tuberculin), and disseminated granulomas in the lungs, spleen, liver, kidneys, lymph nodes, salivary glands, and intestines. The lamina propria throughout the large and small intestines was infiltrated with mycobacteria-laden macrophages. Severe hypoproteinemia, hypoalbuminemia, hypoglobulinemia, mild hypocalcemia, and edema were compatible with a malabsorption-like syndrome. The 2nd animal was clinically normal, but a weak positive tuberculin reaction to M bovis purified protein derivative at 72 hours necessitated euthanasia. This animal's disease was characterized by microgranulomas in the lungs, bronchial lymph nodes, liver, and pancreas, without involvement of the gastrointestinal tract. There was no evidence of M intracellulare infection in the remaining 88 animals in the colony, as determined by mycobacterial cultures of tracheobronchial washings, additional tuberculin testing, thoracic radiography, and mycobacterial culture of the drinking water. Tuberculin testing and thoracic radiographs of personnel working with the nonhuman primates were also negative. These cases were considered to be important because both animals were infected with the same serotype and because there has been an increasing number of isolations of this organism in human infections throughout Massachusetts. Drug-sensitivity testing revealed the organism to be sensitive to cycloserine and resistant to isoniazid, rifampin, ethambutol, streptomycin, kanamycin, and pyrazinamide.