Zeta potential and vancomycin-red blood cell interactions

Vancomycin hydrochloride is a polycationic antibiotic that we have previously reported to cause spontaneous aggregation of red blood cells (RBCs) in vitro at concentrations of more than 3.0 mg/mL, and false-positive direct antiglobulin tests at concentrations of 2.0 and 2.5 mg/mL. These latter reactions were abolished when the RBCs were pretreated with the proteolytic enzyme ficin suggesting an interaction with sialoglycoproteins. In this study we show that prior addition of vancomycin did not block binding of antibodies to several blood group antigens, nor does vancomycin precipitate in an Ouchterlony assay with any of several sialic acid moieties. Finally, we show that vancomycin possesses fluorescent properties but fails to be detected on the RBC surface by flow cytometry. These data indicate that vancomycin may be acting through its polycationic properties. Our findings do not support protein binding of vancomycin to the RBC surface, but underline the importance of the zeta potential in RBC serologic reactions.     

Cigarette Smoking does not Induce Plasma or Pulmonary Oxidative Stress after Moderate-intensity Exercise

[Purpose] Cigarette smoking increases oxidative stress, which is a risk factor for several diseases. Moreover, strenuous exercise has been shown to induce plasma and pulmonary oxidative stress in young cigarette smokers. However, no previous reports have demonstrated whether plasma and pulmonary oxidative stress occur after moderate-intensity exercise. Therefore, the aim of this study was to clarify whether moderate-intensity exercise induces pulmonary and plasma oxidative stress in smokers. [Subjects] Ten young male smokers and 10 young male nonsmokers participated in this study. [Methods] Plasma hydroperoxide concentrations were measured at baseline and then immediately and 15 min after moderate-intensity exercise. Hydrogen peroxide concentrations in exhaled breath condensate were measured at baseline and after exercise. [Results] No significant interactions were found between smokers and nonsmokers in terms of hydroperoxide or hydrogen peroxide concentrations following moderate-intensity exercise at any time point. [Conclusion] These findings suggested that moderate-intensity exercise did not induce plasma or pulmonary oxidative stress in young cigarette smokers.Key words: Oxidative stress, Cigarette smoker, Moderate-intensity exercise     

Automated detection of gait initiation and termination using wearable sensors

This paper presents algorithms for detection of gait initiation and termination using wearable inertial measurement units and pressure-sensitive insoles. Body joint angles, joint angular velocities, ground reaction force and center of plantar pressure of each foot are obtained from these sensors and input into supervised machine learning algorithms. The proposed initiation detection method recognizes two events: gait onset (an anticipatory movement preceding foot lifting) and toe-off. The termination detection algorithm segments gait into steps, measures the signals over a buffer at the beginning of each step, and determines whether this measurement belongs to the final step. The approach is validated with 10 subjects at two gait speeds, using within-subject and subject-independent cross-validation. Results show that gait initiation can be detected timely and accurately, with few errors in the case of within-subject cross-validation and overall good performance in subject-independent cross-validation. Gait termination can be predicted in over 80% of trials well before the subject comes to a complete stop. Results also show that the two sensor types are equivalent in predicting gait initiation while inertial measurement units are generally superior in predicting gait termination. Potential use of the algorithms is foreseen primarily with assistive devices such as prostheses and exoskeletons.     

Expression of Human Telomerase RNA Is an Early Event of Stomach Carcinogenesis

Expression of human telomerase RNA (hTR) and telomerase activity in gastric cancer and corresponding non-cancerous mucosa were studied. Telomerase activity was detected in 23 (88%) of 26 carcinoma tissues. Although all tumor specimens and non-cancerous mucosa expressed various levels of hTR, 21 (81%) of 26 cases expressed hTR at a higher level in the tumor than that in the corresponding mucosa. All 8 gastric carcinoma cell lines also expressed hTR at high levels. Nine (35%) of 26 non-cancerous mucosa showed telomerase activity and all of them contained intestinal metaplasia. The incidence of telomerase-positive mucosa in grade 2 intestinal metaplasia was significantly higher than that in grade 0 or grade 1 intestinal metaplasia, whereas hTR overexpression was found in grade 0 or grade 1 intestinal metaplasia as well as grade 2 intestinal metaplasia. The degree of Heticobacter pylori infection increased in parallel with the level of hTR expression and telomerase positivity. These results overall suggest that Helicobacter pylori infection may he a strong trigger for hTR overexpression in intestinal metaplasia, and this may lead to telomerase reactivation.     

Postoperative Mycoplasma hominis infection after robot‐assisted laparoscopic radical prostatectomy: A case report

A 59‐year‐old man developed a high fever, elevated white blood cell count, elevated C‐reactive protein level, and perineal pain 5 days after robot‐assisted laparoscopic radical prostatectomy. Treatment with cefmetazole was ineffective. A urine specimen was submitted for culture on postoperative day 7, and Mycoplasma hominis (M. hominis) was detected 1 week later. Cefmetazole was therefore switched to quinolone. The clinical symptoms and laboratory data immediately showed marked improvement. M. hominis has been shown to inhabit the genitourinary tract. Although it is considered to induce urethritis, its pathogenicity in healthy male subjects has not been investigated. M. hominis is difficult to detect and is resistant to β‐lactams because it lacks a cell wall. Urine culture sometimes results in false‐negative results. In cases where empirical therapy for postoperative infection is ineffective, surgeons should recognize the possibility of M. hominis involvement and consider changing the antibiotic used.