Infection mechanism of biofilm‐forming Staphylococcus aureus on indwelling foreign materials in mice

Indwelling foreign‐body infections are a critical medical problem, especially in immunocompromised patients. To examine the pathogenicity of biofilm‐forming bacteria settling on foreign materials, mice implanted with plastic discs were infected with Staphylococcus aureus. After opening a wide subcutaneous pocket on the dorsal side of mice with or without temporal leukocytopenia, a plastic sheet was placed in the left subcutaneous space; subsequently, bacteria in a planktonic state were dispersed over the subcutaneous space. Bacterial numbers were examined 7 days after inoculation. In subcutaneous tissue on the right, S. aureus was found only in leukocytopenic mice. Meanwhile, bacteria were detected on the plastic and neighbouring tissue in both leukocytopenic and normal mice; however, colony‐forming analysis indicated that leukocytopenic mice possessed significantly more bacteria. Tissue reaction against bacteria was pathologically examined. Invading S. aureus induced severe inflammation. In transient leukocytopenic mice, bacterial microcolonies formed on the plastic as well as in the developed necrotic tissue – both of which were shielded from inflammatory cell infiltration – result in bacteraemia. These results indicate that biofilm‐forming S. aureus settling on indwelling foreign material are tolerant against host immunity and assault neighbouring tissue, which may lead to chronic wound infection.     

Maternal overweight/obesity characteristics and child anthropometric status in Jos,Nigeria

Objective:

This study is to determine the pattern of overweight and obesity and its relationship with childhood anthropometric status in Nigeria.

Materials and Methods:

This cross-sectional study was conducted in Jos, Nigeria. Interviewer administered questionnaire was used in data collection. Maternal and child anthropometric measurements were obtained using standard WHO methods. Child anthropometric Z scores were obtained from WHO Anthroplus while BMI of mothers were also determined. Totally, 262 mother-child pairs were recruited.

Results:

Mean maternal age and mean child age were 30.8 ± 6.3 yrs (15-47 yrs) and 22.3 ± 18.7 months (3-72 months). Prevalence of maternal underweight, overweight and obesity was 4.2% (11/262), 29.4% (77/262) and 25.9% (68/262), respectively. Child overweight/obesity was 5.4% (14/262), severe under-nutrition 5.7% (15/262). Mean maternal BMI was higher in the older, more educated and higher socioeconomic status (SES). Child mean birth-weight, weight-for-age Z-score and BMI-for-age Z-score (BAZ) were higher among mothers with BMI ≥ 25 kg/m². All large-for-age babies were in mothers with maternal BMI ≥ 25 kg/m². Childhood over-nutrition was more common in maternal BMI of ≥25 kg/m². Overall, BAZ was directly related with maternal BMI, maternal age and birth-weight, although it was inversely related with maternal BM I ≥ 25 kg/m².

Conclusion:

Higher BMI is seen in educated and higher SES mothers and this impact on childhood anthropometry.     

Lidocaine‐Propitocain Cream,a Eutectic Mixture of Local Anesthetics,Effectively Relieves Pain Associated With Vascular Access Intervention Therapy in Patients Undergoing Hemodialysis: A Placebo‐Controlled,Double‐Blind,Crossover Study

Vascular access intervention therapy (VAIVT) is necessary to maintain vascular access in patients undergoing hemodialysis. VAIVT‐associated vasodilatation is painful. However, few reports have focused on effective pain relief at the time of VAIVT. The present study was performed to determine whether lidocaine‐propitocain cream, a eutectic mixture of local anesthetics (EMLA), effectively reduces VAIVT‐associated pain in patients undergoing hemodialysis. This placebo‐controlled, double‐blind, crossover study was conducted in a single center. Among 210 patients who underwent a total of 437 VAIVT procedures from August 2017 to June 2018, 30 patients were randomly allocated to either the EMLA–placebo arm or placebo–EMLA arm at the time of VAIVT. EMLA application significantly reduced the visual analog scale score compared with placebo (47.0 ± 21.1 vs. 68.6 ± 20.7 mm, respectively; P < 0.05). EMLA is a safe and effective treatment for relief of VAIVT‐associated pain in patients undergoing hemodialysis.     

A Paced Auditory Serial Addition Task evokes stress and differential effects on masseter-muscle activity and haemodynamics

This study aimed to determine autonomic and jaw-muscle activities, and haemodynamic responses, to acute experimental mental stress in humans. Eleven healthy men (25.2 ± 3.0 years of age) and five healthy women (23.0 ± 3.7 years of age) performed a standardized mental stress task, the Paced Auditory Serial Addition Task (PASAT). Autonomic function, such as heart rate variability (HRV), and haemodynamic changes were recorded simultaneously. The success rate of the PASAT decreased with increased pace and duration. Low-frequency (5.8 ± 1.1 ms(2)) and high-frequency (5.3 ± 0.6 ms(2)) components of HRV decreased during the PASAT (to 5.0 ± 0.9 ms(2) and 4.6 ± 1.1 ms(2), respectively) as an indication of acute stress. Oxygenated haemoglobin in the masseter muscle (14.6 ± 2.2 10(4) units mm(-3)) remained at an elevated level during the PASAT (15.5 ± 2.5 10(4) units mm(-3)), whereas deoxygenated haemoglobin (7.8 ± 2.3 10(4) units mm(-3)) showed a consistent decrease (to 6.8 ± 2.1 10(4) units mm(-3)). Total haemoglobin and jaw-muscle electromyographic (EMG) activity did not change during the PASAT. Thus, PASAT-induced mental stress changed the parasympathetic/sympathetic balance of the heart and had an acute influence on jaw-muscle haemodynamics, but not on jaw-muscle EMG activity. This non-invasive experimental set-up can be applied to study the effects of repeated or longer-lasting mental stress in order to further the understanding of pathophysiological mechanisms in craniofacial pain conditions.     

Prevalence of Porphyromonas gingivalis fimA genotypes in Japanese children

Porphyromonas gingivalis FimA fimbriae have been classified into 6 genotypes (types I-V and Ib) based on the diversity of the fimA genes encoding the fimbrial subunits. We investigated the prevalence of fimA genotype in Japanese children. Dental plaque specimens were obtained from 400 subjects (age; 2 to 15 years), including 134 with healthy gingiva, 239 with gingivitis and 27 with periodontitis, and then analyzed by polymerase chain reaction. P. gingivalis was detected in 1.5%, 10.0% and 29.6% of these subjects, respectively. Significant differences were observed with regard to P. gingivalis infection among the groups [chi-squared analysis: gingivitis vs. healthy, P < 0.01, odds ratio (OR) = 7.4; periodontitis vs. healthy, P < 0.001, OR = 27.8]. In P. gingivalis-positive subjects with periodontitis, the most prevalent fimA types were type Ib/type II combination (37.5%) and type IV (37.5%), followed by type II (25.0%), while type IV (33.3%) and type II (29.2%) were most often detected in those with gingivitis. Our results suggest that the presence of P. gingivalis is associated with periodontal diseases, and that the type II, IV and Ib/II combination are the most common among fimA genotypes.