Overexpression of Peroxiredoxin 3 in Cartilage Reduces the Severity of Age‐Related Osteoarthritis But Not Surgically Induced Osteoarthritis in Mice

Objective

The study objective was to determine whether overexpression of the mitochondrial antioxidant peroxidase, peroxiredoxin 3 (Prx3), reduces the severity of osteoarthritis (OA) in mice.

Methods

Age‐related OA (age 18 and 24 months) and OA induced by destabilization of the medial meniscus (DMM at age 6 months) were assessed in male mice that overexpress a human Prdx3 transgene encoding the Prx3 protein. Lox‐stop‐lox‐Prdx3 (iPrdx3) mice were crossed with aggrecan‐Cre^ERT2 mice to produce iPrdx3AgCre^ERT2 or with Col2Cre to produce iPrdx3Col2Cre mice. Germline transgenics (Prdx3Tg) were also evaluated. Prx3 protein level was assessed by immunoblotting and functionally after induction of elevated mitochondrial hydrogen peroxide (H₂O₂) using menadione. Histological sections of stifle joints were scored for cartilage damage (Articular Cartilage Structure score [ACS]), osteophytes, and synovial hyperplasia and were evaluated by histomorphometry.

Results

Overexpression of Prx3 maintained mitochondrial membrane integrity and inhibited p38 phosphorylation in the presence of elevated H₂O₂. ACS scores of 18‐month‐old iPrdx3AgCre^ERT2 mice (mean ± SD, 4.88 ± 5.05) were significantly lower than age‐matched iPrdx3 controls (11.75 ± 6.34, P = 0.002) and trended lower in the 18‐month Prdx3Tg group (P = 0.14), whereas no significant differences between experimental and control groups at 24 months of age or in OA induced by DMM surgery were noted. Osteophyte scores trended lower in the 18‐month‐old Prdx3Tg group (P = 0.09) and at 24 months in the iPrdx3Col2Cre mice (P = 0.05). There were no significant group differences in synovial hyperplasia or histomorphometric measures.

Conclusion

Overexpression of the mitochondrial peroxidase Prx3 reduced the severity of age‐related OA, but not at advanced ages and not in DMM‐induced OA in younger mice.

Hydrogen sulfide: Therapeutic or injurious in ischemic stroke?

Hydrogen sulfide (H2S) has been identified as a vasodilatory, neuromodulatory, and anti-inflammatory gasotransmitter with antioxidant properties. Studies focused in cardiac tissue suggest H2S functions as a protective agent; however in the central nervous system (CNS) the effects of H2S during states of stress or injury, such as stroke, remain controversial. Currently, the application of H2S donors and modulators in stroke depends on the type of H2S donor and the timing of the therapy.

Metabolic syndrome after laparoscopic bariatric surgery

BACKGROUND

Metabolic syndrome (MS) is common among morbidly obese patients undergoing bariatric surgery. The aim of this study was to assess the impact and predictors of bariatric surgery on the resolution of MS.

METHODS

Subjects included 286 patients [age 44.0 +/- 11.5, female 78.2%, BMI 48.7 +/- 9.4, waist circumference 139 +/- 20 cm, AST 23.5 +/- 14.9, ALT 30.0 +/- 20.1, type 2 diabetes mellitus (DM) 30.1% and MS 39.2%] who underwent bariatric surgery.

RESULTS

Of the entire cohort, 27.3% underwent malabsorptive surgery, 55.9% underwent restrictive surgery, and 16.8% had combination restrictive-malabsorptive surgery. Mean weight loss was 33.7 +/- 20.1 kg after restrictive surgery (follow up period 298 +/- 271 days), 39.4 +/- 22.9 kg after malabsorptive surgery (follow-up period 306 +/- 290 days), and 28.3 +/- 14.1 kg after combination surgery (follow-up period 281 +/- 239 days). Regardless of the type of bariatric surgery, significant improvements were noted in MS (p values from <0.0001-0.01) as well as its components such as DM (p values from <0.0001-0.0005), waist circumference (p values <0.0001), BMI (p values <0.0001), fasting serum triglycerides (p values <0.0001 to 0.001), and fasting serum glucose (p values <0.0001). Additionally, a significant improvement in AST/ALT ratio (p value = 0.0002) was noted in those undergoing restrictive surgery. Multivariate analysis showed that patients who underwent malabsorptive bariatric procedures experienced a significantly greater percent excess weight loss than patients who underwent restrictive procedures (p value = 0.0451). Percent excess weight loss increased with longer postoperative follow-up (p value <0.0001).

CONCLUSIONS

Weight loss after bariatric surgery is associated with a significant improvement in MS and other metabolic factors.

Tobacco use in Kerala: findings from three recent studies

BACKGROUND

We reviewed the literature on tobacco use in Kerala and present data from three recently conducted unpublished studies.

METHODS

Three cross-sectional studies were conducted; a community-based study of 1,298 individuals aged 15 years and above (mean age 37.4 years, men 630), a school-based study of 1,323 boys (mean age 14.7 years), and a college-based study of 1,254 male students (mean age 18.2 years). Information on tobacco use and sociodemographic variables was collected using pre-tested, structured interview schedules and questionnaires.

RESULTS

In the community study, 72% of men and 6% of women had ever used tobacco. Compared to men with > 12 years of schooling, those with < 5 years of schooling were 7 times more likely to smoke (OR 7, CI 3.2-15.6). The age at initiation of smoking was 19 years among those < 25 years of age compared to 25.5 years among ever smokers > 44 years. In the school study, the age at initiation among boys aged < or = 1 3 years was 10.7 years compared with 13.2 years among > or = 16-year-old boys. Boys whose fathers and friends used tobacco were 2 times and 2.9 times more likely to use tobacco (OR 2.0, CI 1.3-3.1 and OR 2.9, CI 1.6-5.1), respectively, compared with their counterparts. In the college study, 29% of the commerce students used tobacco compared with 5.3% of polytechnic students (p < 0.001).

CONCLUSION

Survey data suggest that the age at initiation of tobacco use appears to be falling. A series of cross-sectional studies with larger sample sizes of the youth is required to confirm this impression. Tobacco use habits of fathers and peers are significant influences on youth smoking. There is a need to focus on particular types of colleges as these appear to have high-risk tobacco use environments.

Prevalence of dental fluorosis and associated risk factors in Alappuzha district, Kerala

BACKGROUND

Fluorosis is considered endemic in 15 states of India. Dental fluorosis is the most convenient biomarker of exposure to fluoride. In Kerala, although the condition is reported to be endemic in the districts of Alappuzha and Palakkad, there are no systematic epidemiological studies evaluating dental fluorosis. We studied the prevalence of dental fluorosis among school children in Ambalappuzha taluk, Alappuzha district, Kerala and evaluated the contribution of potential risk factors.

METHODS

We conducted a community-based, cross-sectional survey of 1142 school children (630 girls, 512 boys) in the age group of 10-17 years, using a multistage random cluster sampling technique. A pre-tested structured questionnaire was used to assess exposure to various sources of fluoride. A dental specialist examined all the children to determine the presence or absence of dental fluorosis and graded the degree of dental fluorosis using Dean's Index. The water fluoride content in the study area was obtained from the district water authority department. Bivariate associations were examined using the Chi-square and Chi-square trend tests, while multiple logistic regression was used to evaluate the association of select risk factors with the presence or absence of dental fluorosis.

RESULTS

The overall prevalence of dental fluorosis in our study sample was 35.6% and the community fluorosis index was 0.69. The prevalence of dental fluorosis was higher in the urban compared to the rural areas (55.3% v. 16.8%; p < 0.001), and in girls compared to boys (39.2% v. 31.3%; p < 0.01). The prevalence of dental fluorosis was higher among children who consumed pipe water as compared to children who consumed well water (44.8% v. 12.7%; p < 0.001). We noted a step-wise increase in the prevalence of dental fluorosis with a corresponding increase in water fluoride content in different panchayats (p = 0.024). The principal factor associated with the presence of dental fluorosis was a high fluoride content of drinking water (OR 1.85, 95% Cl: 1.17-2.92). We did not observe any significant association between dental fluorosis and the intake of brick-tea, consumption of fish or the use of toothpaste.

CONCLUSION

Dental fluorosis is a public health problem in the Ambalappuzha taluk. Active steps must be taken to partially defluoridate the water before distribution to reduce the morbidity associated with dental fluorosis in this area. Similar surveys are required in other parts of India to identify areas with high water fluoride content and determine the extent and manner in which defluoridation can be carried out.

Pulmonary tuberculosis and coexisting carcinoma: a 10-year experience and review of the literature

Of 7,986 patients admitted to Mount Wilson State Hospital for Pulmonary Diseases between 1960 and 1970, 72 were proven to have coexisting pulmonary tuberculosis and bronchogenic carcinoma. The patients usually were in the older age group, and usually smoked. There was a high predilection for the tumor to occur in the upper lobes. Active tuberculosis was present in 50 per cent of the patients and tumor and tuberculosis was present in the same area 80 per cent of the time. Cell diagnosis was possible in 60 per cent of the patients without thoracotomy. Diagnosis was usually made late in the course of the disease and therapeutic results were poor. Only 13 patients were operable and only four are presently alive. Earlier recognition is vital to adequate treatment. A plan for earlier recognition based on a high degree of suspicion is presented.