Subepicardial burn injuries in bullfrog heart induce electrocardiogram changes mimicking inferior wall myocardial infarction

Using bullfrog hearts, we previously reproduced a ST segment elevation in electrocardiogram (ECG), mimicking human ischemic heart disease. In the present study, by inducing subepicardial burn injuries on the inferior part of the frog heart ventricle, we could reproduce typical ECG changes observed in human inferior wall myocardial infarction, such as the marked elevation of the ST segments in inferior limb leads (II, III, aVF) and their reciprocal depression in the opposite limb leads (I, aVL). Due to the decrease in Na⁺/K⁺-ATPase protein expression, the resting membrane potential of injured cardiomyocytes shifted toward depolarization. Such induced electrical difference between the injured and intact cardiomyocytes was thought to be responsible for the creation of “currents of injury” and the subsequent ST segment changes.

Maladjustment of programmable ventricular shunt valves by inadvertent exposure to a common hospital device

Background:

Programmable ventricular shunt valves are commonly used to treat hydrocephalus. They can be adjusted to allow for varying amounts of cerebrospinal fluid (CSF) flow using an external magnetic programming device, and are susceptible to maladjustment from inadvertent exposure to magnetic fields.

Case Description:

We describe the case of a 3-month-old girl treated for hydrocephalus with a programmable Strata^TM II valve found at the incorrect setting on multiple occasions during her hospitalization despite frequent reprogramming and surveillance. We found that the Vocera badge, a common hands-free wireless communication system worn by our nursing staff, had a strong enough magnetic field to unintentionally change the shunt setting. The device is worn on the chest bringing it into close proximity to the shunt valve when care providers hold the baby, resulting in the maladjustment.

Conclusion:

Some commonly used medical devices have a magnetic field strong enough to alter programmable shunt valve settings. Here, we report that the magnetic field from the Vocera hands-free wireless communication system, combined with the worn position, results in shunt maladjustment for the Strata^TM II valve. Healthcare facilities using the Vocera badges need to put protocols in place and properly educate staff members to ensure the safety of patients with Strata^TM II valves.

Multiplexing capability in polychromatic reconstruction with selective detection method

Holographic reconstruction with polychromatic light was investigated in terms of the multiplexing capability in a volume holographic memory. The broadband spectrum of the probe beam considerably degrades the angular selectivity and causes a serious deterioration of the multiplexing capability, but this can be overcome if an additional suitable optical component is used in the imaging system. We could selectively detect the signal image alone even though the angular separation between holograms was insufficient to suppress the diffraction from other holograms. We theoretically derived the minimum angular separation for multiplexing and experimentally demonstrated the effectiveness of this selective detection method.

Inhibitory effects of bovine lactoferrin on the adherence of enterotoxigenic Escherichia coli to host cells

Adherence is an essential and prerequisite step for the colonization of mucosal surfaces by enterotoxigenic Escherichia coli (ETEC). We studied the effect of bovine lactoferrin (BLF) on the adherence of ETEC to human epithelial cells in vitro, and to intestinal mucosa of ICR germfree mice in vivo. In the in vitro study, BLF was found to inhibit the adherence of ETEC. This adhesion-inhibiting activity of BLF was found to lessen with decreasing BLF concentration, but the data obtained suggest a positive inhibitory effect of BLF against the adhesion of ETEC cells. In the in vivo study, the counts of adherent bacteria in various sections of the intestinal tract (duodenum, jejunoileum, and large intestine) were lower in the BLF group than in the control group, suggesting the possible action of BLF as an intestinal tract adherence-blocking agent with regards to ETEC.

Normalization of reproductive function in germfree mice following bacterial contamination

The capacity for reproduction in germfree mice remain inferior to their conventional counterparts even after improvement of feed and other such rearing conditions. The authors provide evidence of increased reproductive capacity in germfree mice following association with bacteria. Estrous cycles were normalized in female mice accidentally contaminated with bacteria, and in mice given fecal suspensions of the accidentally contaminated mice per os. Significant rises were seen in their copulation and implantation rates, reaching levels comparable to values in conventional mice. In male mice, bacterial contamination induced significant increase in sperm motility. Bacteria were identified in the feces of the contaminated mice, and reproductive capacity was examined in mice associated with the identified bacteria. As a result, normalization of the estrous cycle, and rises in copulation and implantation rates were noted in B. distasonis and C. perfringens di-associated mice. Values from B. subtilis mono-associated mice were comparable to those in germfree mice. These results from our accidental contamination indicate that B. distasonis and C. perfringens are capable of normalizing estrous cycles in female germfree mice, and in increasing their reproductive capacity by raising their rates of copulation and implantation.

Effects of a single bout of resistance exercise on calcium and bone metabolism in untrained young males

Although resistance exercise training appears to increase bone mineral density in the long term, a single bout of resistance exercise could paradoxically induce bone homeostasis disturbance, secondary to metabolic acidosis. To examine this, we obtained fasting blood and 24-hour urine samples from untrained male subjects for 5 subsequent days (control day, exercise day, and three post-exercise days), and investigated the effects of a single bout of resistance exercise on urinary calcium excretion and bone metabolism as indicated by sensitive biomarkers of bone formation and resorption. After an intense bout of resistance exercise, blood and urine became more acidic and renal net acid excretion significantly increased by 44% on the exercise day. Urinary calcium excretion significantly increased by 48% on the exercise day. Plasma procollagen type-I C-terminal concentration significantly decreased by 12% on the next day of the exercise and serum bone-specific alkaline phosphatase activity also significantly decreased by 13% and 9% on days 2 and 3, respectively, after the exercise. There was no significant change in serum osteocalcin concentration. Serum tartrate-resistant acid phosphatase activity significantly decreased by 15% on the day after the exercise and urinary deoxypyridinoline excretion decreased by 22% and 27% on days 1 and 3, respectively, after the exercise. These results suggest that the early response of bone to a bout of resistance exercise in untrained individuals was transient decreases in bone formation and resorption, whereas urinary calcium excretion increased.

A bout of resistance exercise increases urinary calcium independently of osteoclastic activation in men

Metabolic acidosis increases urinary calcium excretion in humans as a result of administration of ammonium chloride, an increase in dietary protein intake, and fasting-induced ketoacidosis. An intense bout of exercise, exceeding aerobic capacity, also causes significant decrease in blood pH as a result of increase in blood lactate concentration. In this study we investigated changes in renal calcium handling, plasma parathyroid hormone concentration, and osteoclastic bone resorption after a single bout of resistance exercise. Ten male subjects completed a bout of resistance exercise with an intensity of 60% of one repetition maximum for the first set and 80% of one repetition maximum for the second and third sets. After exercise, blood and urine pH shifted toward acidity and urinary calcium excretion increased. Hypercalciuria was observed in the presence of an increased fractional calcium excretion and an unchanged filtered load of calcium. Therefore, the observed increase in urinary calcium excretion was due primarily to decrease in renal tubular reabsorption of calcium. Likely causes of the increase in renal excretion of calcium are metabolic acidosis itself and decreased parathyroid hormone. When urinary calcium excretion increased, urinary deoxypyridinoline, a marker of osteoclastic bone resorption, decreased. These results suggest that 1) strenuous resistance exercise increased urinary calcium excretion by decreasing renal tubular calcium reabsorption, 2) urinary calcium excretion increased independently of osteoclast activation, and 3) the mechanism resulting in postexercise hypercalciuria might involve non-cell-mediated physicochemical bone dissolution.

Effect of resistance exercise training on bone formation and resorption in young male subjects assessed by biomarkers of bone metabolism

We studied the effects of high intensity resistance exercise training on bone metabolism in 17 young adult Oriental males (23-31 years) by measuring sensitive biomarkers of bone formation and resorption. The subjects were assigned to a training group and a sedentary group. The training group followed a weight training program three times per week for 4 months. In the training group, serum osteocalcin concentration and serum bone-specific alkaline phosphatase activity were significantly increased within the first month after the beginning of resistance exercise training, and the elevated levels remained throughout the training period, while there was no significant change in plasma procollagen type-I C-terminal concentration. Urinary deoxypyridinoline excretion was transiently suppressed and returned to the initial value but was never stimulated during the 4 months. These results suggest that the resistance exercise training enhanced bone formation without prior bone resorption. In the sedentary group, there was no significant difference in bone metabolic markers except plasma procollagen type-I C-terminal, which continuously decreased during the experimental period. There were no significant changes in total and regional bone mineral density in either group. In conclusion, (1) resistance exercise training increased markers of bone formation, while it transiently suppressed a marker of bone resorption, and (2) such adaptive changes of bone metabolism to resistance exercise training occurred during the early period of the training, before changes in bone density were observable through densitometry.

Development of a CAI program entitled 'Introduction to Nursing Process'. Requirement for nursing education in Japan

A new teaching strategy is required in nursing education in Japan. A multimedia CAI (Computer Assisted Instruction) program entitled "Introduction to Nursing Process." was developed. The aim of this study was to examine whether CAI could assist students' knowledge acquisition, and increase their motivation and readiness to learn clinical nursing practice. This study involved the process of developing CAI and a pilot study for measuring and evaluating the CAI program. Results demonstrate that CAI can increase students' understanding about the nursing process, enhance their motivation to learn, and provide realistic situations describing the concept of nursing the process.