Osteopenia: a bone disorder associated with diabetes mellitus

Although osteopenia has been associated with human diabetes mellitus, the pathogenesis of diabetic osteopenia is unclear. In the present study, we evaluated the effect of diabetes on histomorphometry, bone mineral density (BMD)—measured by dual-energy X-ray absorptiometry (DXA)—and biomarkers of bone metabolism in rats up to 120 days after the onset of experimental diabetes. Female Wistar rats with a regular estrous cycle were randomly divided into two groups: control rats (n = 15) and diabetic rats without insulin treatment (n = 25). Diabetes was induced by injection of alloxan and was confirmed by the determination of blood glucose concentration (>250mg/dl). The results revealed an approximate threefold increase of femoral trabecular distance in diabetic rats compared to controls. Conversely, trabecular thickness and bone trabecular volume were reduced twofold and 77%, respectively. BMD in both the metadiaphyseal region and total area of the femur was found to be clearly reduced in diabetic animals, with no significant differences between the groups. Serum alkaline phosphatase (ALP) and tartarate-resistant acid phosphatase (TRAP) activities showed significant six- and twofold increases, respectively, in diabetic rats. There were significant decreases in serum calcium and albumin concentrations in diabetic rats, but no difference was observed in serum magnesium, phosphorus, or creatinine concentrations between the groups. Overall, our findings support the conclusion that the diabetic state is associated with alterations in bone turnover, resulting in the development of osteopenia, which is related to the time of evolution of the disorder.     

Immunological and echocardiographic evaluation of decellularized versus cryopreserved allografts during the Ross operation.

OBJECTIVE: Compare the immunological and echocardiographic data of decellularized versus cryopreserved allografts used for RVOT reconstruction during Ross operation. METHODS: From 16/01/03 thru 07/10/03, 20 Ross operations were performed using decellularized (n=11) or cryopreserved (n=9) allografts. Echocardiography was done at discharge, 1, 3, 6 and 12 months and annually thereafter. Samples for determination of antibodies against HLA class I and II were obtained preoperatively and at days 5, 10, 30, 90 and 180 postoperatively. These samples were tested by the ELISA method in LAT-M dishes (unspecific) for identification of circulating antibodies and the results expressed as mean sample values (Is=DO/cutoff). If positive, LAT-E (specific) was performed and PRA levels determined. RESULTS: There was no mortality. Cryopreserved allografts showed marked Is values elevations for class I and II antibodies which started at the first month and remained elevated up to 6 months. In contrast, of the patients receiving decellularized allografts, seven remained negative, two patients had only marginal elevation of class I antibodies and two patients showed abnormal elevations of PRA levels. This response happened earlier than in the cryopreserved group, starting on the 5th postoperative day and has returned to baseline levels in one case. Echocardiography showed mild, but significant, elevation of gradients in cryopreserved valves but none in the decellularized. CONCLUSIONS: Decellularized allografts had normal function up to 18 months and showed important reduction of the immunogenic response when compared to cryopreserved valves.     

BMP binding peptide: a BMP-2 enhancing factor deduced from the sequence of native bovine bone morphogenetic protein/non-collagenous protein.

Forty years ago, Marshall Urist described a partially purified extract of demineralized bone matrix which induced the formation of ectopic bone. This substance, bone morphogenetic protein/non-collagenous protein (BMP/NCP), was never purified to homogeneity but other investigators used similar starting materials to clone a number of recombinant BMPs. Urist recognized that his material probably contained the BMPs which had been cloned by others but always contended that it contained another, more potent, bone inducing material which differed significantly in its physical and chemical properties from the known BMPs. We have used Urist's protocol to isolate a protein that has the chemical and physical properties of Urist's "BMP". It is an 18.5 kD fragment of the bone matrix protein, SPP-24. This fragment contains the cystatin-like domain of SPP-24. We have located a 19 amino acid region which is similar to the TGF-beta/BMP-binding region of fetuin, a member of the cystatin family of protease inhibitors. A cyclic peptide, which we call BMP binding peptide (BBP) was generated using this sequence. The peptide avidly bound rhBMP-2 with a KD of 3 x 10(-5) M. When implanted alone in mouse muscle, the peptide frequently induced dystrophic calcification. When implanted with rhBMP-2, the peptide enhanced the osteogenic activity of the recombinant molecule. We hypothesize that Urist's "BMP" was a fragment of SPP-24 which influenced bone induction by binding to bone morphogenetic proteins. BBP may be clinically useful because of its effects on other bone-inducing substances.     

An evaluation of the treatment of parapsoriasis with phototherapy

Whether parapsoriasis represents an early stage of T-cell cutaneous lymphoma is stillthe subject of controversy. We evaluated the efficacy of phototherapy in thetreatment of parapsoriasis and its relation with TCCL. Patients diagnosed withparapsoriasis and treated with phototherapy PUVA or UVB-NB were selected. Between 1to 8 years following treatment the evolution of their disease was evaluated. In 62patients the cure rate was 79.3% and 17.2% showed improvement of the lesions. Onlytwo patients developed full blown T-cell cutaneous lymphoma. Phototherapy is anexcellent treatment for parapsoriasis, with high cure rates, regardless of the typeof phototherapy employed. Of the 62 patients under study, parapsoriasis showed nogeneral tendency to progress to T-cell cutaneous lymphoma.     

The regenerative potential of fibroblasts in a new diabetes‐induced delayed humanised wound healing model

Cutaneous diabetic wounds greatly affect the quality of life of patients, causing a substantial economic impact on the healthcare system. The limited clinical success of conventional treatments is mainly attributed to the lack of knowledge of the pathogenic mechanisms related to chronic ulceration. Therefore, management of diabetic ulcers remains a challenging clinical issue. Within this context, reliable animal models that recapitulate situations of impaired wound healing have become essential. In this study, we established a new in vivo humanised model of delayed wound healing in a diabetic context that reproduces the main features of the human disease. Diabetes was induced by multiple low doses of streptozotocin in bioengineered human‐skin‐engrafted immunodeficient mice. The significant delay in wound closure exhibited in diabetic wounds was mainly attributed to alterations in the granulation tissue formation and resolution, involving defects in wound bed maturation, vascularisation, inflammatory response and collagen deposition. In the new model, a cell‐based wound therapy consisting of the application of plasma‐derived fibrin dermal scaffolds containing fibroblasts consistently improved the healing response by triggering granulation tissue maturation and further providing a suitable matrix for migrating keratinocytes during wound re‐epithelialisation. The present preclinical wound healing model was able to shed light on the biological processes responsible for the improvement achieved, and these findings can be extended for designing new therapeutic approaches with clinical relevance.     

Correlates of change in self-perceived oral health among older adults in Brazil: findings from the Health, Well-Being and Aging Study

BackgroundIdentifying changes in the oral health status of older populations, and their predictors and explanations, is necessary for public health planning. The authors assessed patterns of change in oral health–related quality of life in a large cohort of older adults in Brazil during a five-year period and evaluated associations between baseline characteristics and those changes.MethodsThe sample consisted of 747 older people enrolled in a Brazilian cohort study called the Health, Well-Being and Aging (Saúde, Bem-estar e Envelhecimento [SABE]) Study. Trained examiners measured participants' self-perceived oral health by using the General Oral Health Assessment Index (GOHAI). The authors calculated changes in the overall GOHAI score and in the scores for each of the GOHAI's three dimensions individually by subtracting the baseline score from the score at follow-up. A positive difference indicated improvement in oral health, a negative difference indicated a decline and a difference of zero indicated no change.ResultsThe authors found that 48.56 percent of the participants experienced a decline in oral health and 33.48 percent experienced an improvement. Participants with 16 or more missing teeth and eight or more years of education were more likely to have an improvement in total GOHAI score. Deterioration was more likely to occur among those with two or more diseases. Improvement and decline in GOHAI functional scores were related to the number of missing teeth. The authors found no significant model for the change in the psychosocial score, and self-rated general health was the only variable related to both improvement and decline in pain or discomfort scores.ConclusionsThe authors observed a bidirectional change in self-perceived oral health, with deterioration predominating. The strongest predictor of improvement in the total GOHAI score was the number of missing teeth, whereas the number of diseases was the strongest predictor of deterioration.Clinical ImplicationsDental professionals and policymakers need to know the directions of change in older adults' oral health to establish treatment priorities and evaluate the impact of services directed at this population.     

In vitro susceptibility of oral Candida albicans strains to different pH levels and calcium hydroxide saturated aqueous solution

Candida albicans is present in the oral cavity and in the whole digestive tract of humans and other animals, being frequently related to endodontic treatment failure. The present study determined the incidence of C. albicans in the oral cavity and the susceptibility of isolates to different pH values and saturated calcium hydroxide aqueous solution at pH 12.5. Sixty-five patients attending the Endodontic Clinic at the Sagrado Cora??o University participated in the study. The collected samples were cultivated in selective media for C. albicans and the isolates were tested in terms of resistance to both alkaline pH and saturated aqueous solution of calcium hydroxide. In relation to time variables, yeast viability was assessed by the Sabouraud's agar culture and fluorescein diacetate and ethidium bromide fluorescent staining method. Results from the different pHs and experimental times, including those from different techniques measuring fungal viability, were compared using the chi-square and Fisher's exact tests (α=0.05). The yeasts became completely inviable after 48 h of contact with the calcium hydroxide solution. On the other hand, when exposed to the alkaline culture broth, the yeasts were found to be viable at pHs 9.5 and 10.5 for up to 7 days. In conclusion, C. albicans can only be completely inhibited by direct contact with saturated calcium hydroxide aqueous solution after 48 h of exposure.     

Immunohistochemistry and polymerase chain reaction on paraffin-embedded material improve the diagnosis of cutaneous leishmaniasis in the Amazon region

Background  Recently, there has been an increase in the incidence of cutaneous leishmaniasis (CL), which represents an important health problem. This increase may be related to the epidemiologic expansion of the infective agent and the increase in tourism in tropical areas. The difficulty in clinical diagnosis, mainly in areas in which CL is not the first consideration of local physicians, has intensified efforts to describe diagnostic tests, which should be specific, sensitive, and practical. Amongst the new tests described are those including nucleic acid amplification (polymerase chain reaction, PCR) and immunohistochemistry (IHC).
Methods  In this study, we evaluated the sensitivity of a PCR based on small subunit (SSU) ribosomal DNA, in comparison with IHC using Leishmania spp. antibodies, in biopsies embedded in paraffin.
Result  The results indicated a total sensitivity of 96% (90.9% with PCR and 68.8% with IHC), showing the possibility of using paraffin-embedded biopsies to diagnose CL.
Conclusion  We propose the use of the two tests together as a routine protocol for diagnosis. This would require the provision of local medical services to perform molecular biology techniques and adequate Leishmania antibodies.