Facultative and anaerobic consortia of haloalkaliphilic ureolytic micro-organisms capable of precipitating calcium carbonate.

AIMS: Development of biomineralization technologies has largely focused on microbially induced carbonate precipitation (MICP) via Sporosarcina pasteurii ureolysis; however, as an obligate aerobe, the general utility of this organism is limited. Here, facultative and anaerobic haloalkaliphiles capable of ureolysis were enriched, identified and then compared to S. pasteurii regarding biomineralization activities. METHODS AND RESULTS: Anaerobic and facultative enrichments for haloalkaliphilic and ureolytic micro-organisms were established from sediment slurries collected at Soap Lake (WA). Optimal pH, temperature and salinity were determined for highly ureolytic enrichments, with dominant populations identified via a combination of high-throughput SSU rRNA gene sequencing, clone libraries and Sanger sequencing of isolates. The enrichment cultures consisted primarily of Sporosarcina- and Clostridium-like organisms. Ureolysis rates and direct cell counts in the enrichment cultures were comparable to the S. pasteurii (strain ATCC 11859) type strain. CONCLUSIONS: Ureolysis rates from both facultatively and anaerobically enriched haloalkaliphiles were either not statistically significantly different to, or statistically significantly higher than, the S. pasteurii (strain ATCC 11859) rates. Work here concludes that extreme environments can harbour highly ureolytic active bacteria with potential advantages for large scale applications, such as environments devoid of oxygen. SIGNIFICANCE AND IMPACT OF THE STUDY: The bacterial consortia and isolates obtained add to the possible suite of organisms available for MICP implementation, therefore potentially improving the economics and efficiency of commercial biomineralization.

Cardiac structure and functions in patients with asymptomatic primary hyperparathyroidism.

BACKGROUND: The data about cardiovascular (CV) changes in patients with asymptomatic primary hyperparathyroidism (PHPT) are scarce. AIM: The aim of this study is to compare cardiac structure and functions in patients with asymptomatic PHPT and controls by using tissue Doppler echocardiography. SUBJECTS AND METHODS: Thirty-eight patients with asymptomatic PHPT and 31 sex- and age-matched controls with similar cardiac risk factors were evaluated. RESULTS: There was no significant difference in ejection fraction (EF) between the patients and the controls [64±5.95 vs 62±3.25% (p=0.094)]. Left ventricular mass index (LVMI) was significantly higher in patients than controls [105.96 (66.45-167.24) vs 93.79 (64.25- 139.25) g/m2, p=0.014]. There was a significant correlation between LVMI and serum calcium (Ca) (r=0.240, p<0.005). Myocardial performance index (MPI) was significantly higher in patients than controls [0.49 (0.35-0.60) vs 0.39 (0.33-0.62), p<0.001]. There was positive correlation between theMPI and serumCa levels (r=0.505, p<0.001), parathyroid hormone (PTH) levels (r=0.464, p<0.001) and LVMI (r=0.270, p<0.005). When the normotensive patients and controls were evaluated, the difference between the groups remained statistically significant considering LVMI and MPI [109 (66.45-167.24) g/m2 vs 94.17 (64.25-75.10) g/m2, p=0.03; and 0.49 (0.35-0.60) vs 0.39 (0.33-0.62), p<0.01, respectively]. There were significant correlations between MPI and Ca (r=0.566, p<0.001), and PTH (r=0.472, p<0.001). CONCLUSIONS: Our study results showed that cardiacmorphology and diastolic functions are altered in the patients with asymptomatic PHPT. High serum PTH and Ca levels may have an impact on these CV changes. Whether these subtle CV changes would affect cardiac systolic functions and mortality in patients with asymptomatic PHPT should be investigated in further prospective studies.

Endothelial dysfunction in primary Sjögren syndrome / Disfunción endotelial en el síndrome de Sjögren primario

OBJECTIVE: In this study, we aimed to investigate endothelial functions in primary Sjögren syndrome. METHODS: Thirty-five patients with primary Sjögren syndrome and 20 age and sexmatched healthy volunteers were recruited to the present study. Flow mediated dilatation of brachial artery and carotid intimamedia thickness were measured in the study population. RESULTS: Carotid intimamedia thickness values were similar between groups (0.50 ± 0.10, 0.53 ± 0.08, p > 0.05). Flow mediated dilatation of the brachial artery was disrupted in the primary Sjögren syndrome group (7% vs 12%, p = 0.002). CONCLUSION: There is endothelial dysfunction in patients with primary Sjögren syndrome, although they had comparable carotid intimamedia thickness with the healthy control group.

OBJETIVO: Este estudio se encaminó a investigar las funciones endoteliales en el síndrome de Sjögren primario. MÉTODOS: Para el presente estudio, se reclutaron treinta y cinco pacientes con síndrome de Sjögren primario y 20 voluntarios sanos apareados por edad y sexo. La dilatación mediada por flujo observada en la arteria braquial, y el espesor íntimamedia carotídeo fueron medidos en la población bajo estudio. RESULTADOS: Los valores del espesor íntimamedia carotídeo fueron similares entre los grupos (0.50 ± 0.10, 0.53 ± 0.08, p > 0.05). La dilatación mediada por flujo de la arteria braquial, estaba alterada en el grupo de síndrome del Sjögren primario (7% frente a 12%, p = 0.002). CONCLUSIÓN: Hay una disfunción endotelial en los pacientes con el síndrome de Sjögren primario, aunque estos tenían un espesor íntimamedia carotídeo comparable con el grupo de control saludable.

Endothelial dysfunction in primary Sjögren syndrome.

OBJECTIVE: In this study, we aimed to investigate endothelial functions in primary Sjögren syndrome. METHODS: Thirty-five patients with primary Sjögren syndrome and 20 age and sex-matched healthy volunteers were recruited to the present study. Flow mediated dilatation of brachial artery and carotid intima-media thickness were measured in the study population. RESULTS: Carotid intima-media thickness values were similar between groups (0.50 +/- 0.10, 0.53 +/- 0.08, p > 0.05). Flow mediated dilatation of the brachial artery was disrupted in the primary Sjögren syndrome group (7% vs 12%, p = 0.002). CONCLUSION: There is endothelial dysfunction in patients with primary Sjögren syndrome, although they had comparable carotid intima-media thickness with the healthy control group.