Relative bioavailability and pharmacokinetic comparison of calcium glucoheptonate with calcium carbonate.

Adequate calcium intake is important for the prevention of bone loss and osteoporosis. For some populations such as those of Southeast Asia where calcium intake is very low, supplements represent a suitable dietary source of calcium. The objective of this study was to compare the relative oral bioavailability of calcium from calcium glucoheptonate, a highly soluble calcium salt containing 8.2% of elemental calcium, to that of calcium carbonate. A single-dose, randomized-sequence, open-label, two-period crossover study, with a 7-day washout period, was conducted in 24 Indonesian healthy adult volunteers. After a 12-hour (overnight) fast, subjects received either two oral ampoules of 250 mg/10 mL of calcium glucoheptonate each or one effervescent tablet of calcium carbonate containing 500 mg of elemental calcium. The relative oral bioavailability of calcium from calcium glucoheptonate as compared to calcium carbonate was 92% within 6 hours and 89% within 12 hours after study drug administration. The 90% confidence intervals for the mean test/reference ratios of the maximum plasma concentration and the area under the concentration-time curve at 12 hours post-administration were 77.09%-120.31% and 60.58%-122.30%, respectively. Five subjects experienced a total of eight adverse events which were all mild and transient; no serious adverse events or deaths were reported. These results indicate that calcium glucoheptonate is associated with a high relative bioavailability of calcium compared to calcium carbonate, and is well-tolerated. Calcium glucoheptonate might thus be a potential choice for calcium supplementation in Southeast Asian populations.

The Role of Genetic Testing in Patients With Breast Cancer: A Review.

Importance: In the United States from 2009 to 2013, the incidence of breast cancer was the highest of any cancer and the death rate was second to that of lung cancer. Approximately 5% to 10% of breast cancers are inheritable. Observations: BRCA1 and BRCA2 germline mutations account for up to 30% of inheritable breast cancers and are the most commonly assessed mutations in patients presenting with early-onset breast cancer, triple-negative breast cancer, bilateral breast cancer, and a family history of breast cancer. Less common non-BRCA mutations have also been identified and contribute to hereditary breast cancer syndromes. Although established in BRCA mutations, indications and interpretations of genetic testing in non-BRCA mutations are not well defined. Furthermore, costs associated with genetic testing are highly variable and dependent on laboratory pricing, insurance coverage, and individual risk factors. Conclusions and Relevance: Genetic testing is a powerful tool that allows for the detection of BRCA and non-BRCA germline mutations in individuals with high risks of breast cancer, which in turn aids in the individualization of treatment. Given the magnitude of this disease, it is of great benefit for physicians, including general surgeons, to understand the indications, interpretations, and costs associated with genetic testing in patients with breast cancer. Cost is an especially important part of the genetic testing process and point of discussion with patients.

Decreased snake venom metalloproteinase effects via inhibition of enzyme and modification of fibrinogen.

Since the introduction of antivenom administration 120 years ago to treat venomous snake bit, it has been the gold standard for saving life and limb. However, this therapeutic approach is not always effective and not without potential life-threatening side effects. We tested a new paradigm to abrogate the plasmatic anticoagulant effects of fibrinogenolytic snake venom metalloproteinases by modification of fibrinogen with iron and carbon monoxide and by inhibiting these Zn(2+) dependent metalloproteinases directly with carbon monoxide exposure. Assessment of the fibrinogenolytic effects of venoms collected from Puff adder, Gaboon viper and Indian cobra snakes on plasmatic coagulation kinetics was performed with thrombelastography. Pretreatment of plasma with iron and carbon monoxide exposure markedly attenuated the effects of all three venoms, and direct pretreatment of each venom with carbon monoxide also significantly decreased the ability to compromise coagulation. These results demonstrated that the introduction of a transition metal (e.g., modulation of the α-chain of fibrinogen with iron), modulation of transition metal in heme (e.g., carbon monoxide modulation of fibrinogen-bound heme iron), and direct inhibition of transition metal containing venom enzymes (e.g., CO binding to Zn(2+) or displacing Zn(2+) from the catalytic site) significantly decreased fibrinogenolytic activity. This biometal modulation strategy to attenuate the anticoagulant effects of snake venom metalloproteinases could potentially diminish hemostatic injury in envenomed patients until antivenom can be administered.