Work engagement influencing factors of Japanese midwives working in prenatal medical centers

INTRODUCTION

There have been significant changes in the work environment of midwives, such as the establishment of prenatal medical centers and shared wards for obstetrics and other departments. These changes in the work environment pose a psychological burden on midwives. Under these circumstances, the concept of work engagement is essential for overcoming the ensuing difficulties. However, no studies have yet investigated midwives working in prenatal medical centers in Japan. This study examined the factors affecting work engagement among midwives working in prenatal medical centers in Japan.

METHODS

A cross-sectional survey of 498 midwives working at prenatal medical centers nationwide was conducted. Data were analyzed using the Mann-Whitney U test or Kruskal-Wallis test, correlation analysis using Spearman's rank correlation coefficient, and multiple regression analysis as linear regression.

RESULTS

The median of work engagement score was 3.00 (IQR: 2.40-3.60). The multiple linear regression analysis showed that professional identity (β=0.494, p<0.001), resilience (β=0.243, p<0.001), presence of in-hospital midwifery in the facility (β=0.138, p<0.011), and age (β=0.085, p=0.021) were significant. The adjusted R2 value was 0.490 (p<0.001).

CONCLUSIONS

These results offer management insights into improving work engagement among midwives working in prenatal medical centers in Japan. The proposed measures include hospital/ward administrators establishing the professional identity of midwives and providing them with opportunities to demonstrate their expertise, for instance, within in-hospital midwifery systems at perinatal medical centers.

Preterm toddlers have low nighttime sleep quality and high daytime activity

A number of studies have been made on the sleep characteristics of children born preterm in an attempt to develop methods to address the sleep problems commonly observed among such children. However, the reported sleep characteristics from these studies vary depending on the observation methods used, i.e., actigraphy, polysomnography and questionnaire. In the current study, to obtain reliable data on the sleep characteristics of preterm-born children, we investigated the difference in sleep properties between 97 preterm and 97 term toddlers of approximately 1.5 years of age using actigraphy. Actigraphy units were attached to the toddlers' waists with an adjustable elastic belt for 7 consecutive days, and a child sleep diary was completed by their parents. In the study, we found that preterm toddlers had more nocturnal awakenings and more daytime activity, suggesting that preterm-born children may have a different process of sleep development in their early development.

An Evaluation of the Signs of Nipple Trauma Associated With Breastfeeding: A Delphi Study

BACKGROUND

No consensus on the definitions of nipple trauma has been reported. Thus, different individuals assess identical events inconsistently.

RESEARCH AIMS

To establish clear definitions for the seven signs of nipple trauma related to breastfeeding-erythema, swelling, scabbing, blistering, fissure, purpura, and peeling-and to reach consensus among multiple specialists.

METHODS

We implemented a longitudinal, prospective survey design using a 3-step Delphi method. In the first survey we targeted specialists in breastfeeding, dermatology, and cosmetics, and we presented images as representative cases during a set of semi-structured interviews. In the second and third surveys, we questioned midwives who were certified as "advanced midwives" through mail, using a questionnaire prepared based on the results of the first survey. The agreement criteria of this study were as follows: (1) a median of 2.0 or below; (2) an interquartile range of 1.0 or below; and (3) at least 51% showing responses of either "strongly agree" or "agree."

RESULTS

Based on the responses of the 42 experts, we reached a consensus on 48 items: eight related to erythema, 10 to swelling, nine to scabbing, seven to blistering, seven to fissure, four to purpura, and three to peeling. We then classified these items based on the condition or possible mechanism of the wound. Finally, we developed an observation tool: "seven signs of nipple trauma associated with breastfeeding," along with images.

CONCLUSIONS

Application of this tool for breastfeeding support could improve objectivity in observing and evaluating nipple trauma.

Sleep maturation influences cognitive development of preterm toddlers

Our recent study on full-term toddlers demonstrated that daytime nap properties affect the distribution ratio between nap and nighttime sleep duration in total sleep time but does not affect the overall total amount of daily sleep time. However, there is still no clear scientific consensus as to whether the ratio between naps and nighttime sleep or just daily total sleep duration itself is more important for healthy child development. In the current study, to gain an answer to this question, we examined the relationship between the sleep properties and the cognitive development of toddlers born prematurely using actigraphy and the Kyoto scale of psychological development (KSPD) test. 101 premature toddlers of approximately 1.5 years of age were recruited for the study. Actigraphy units were attached to their waist with an adjustable elastic belt for 7 consecutive days and a child sleep diary was completed by their parents. In the study, we found no significant correlation between either nap or nighttime sleep duration and cognitive development of the preterm toddlers. In contrast, we found that stable daily wake time was significantly associated with better cognitive development, suggesting that sleep regulation may contribute to the brain maturation of preterm toddlers.

Daytime nap and nighttime breastfeeding are associated with toddlers' nighttime sleep

The purpose of the present study is to examine the association between toddlers' sleep arrangements and their nighttime sleep duration and other sleep variables. For this investigation, we performed a study in which child activity and sleep levels were recorded using actigraphy. The parents of 1.5-year-old toddlers (n = 106) were asked to attach an actigraphy unit to their child’s waist with an adjustable elastic belt and complete a sleep diary for 7 consecutive days. Questionnaires were used to assess the sleep arrangements of the toddlers. There was a significant negative correlation between nap duration and nighttime sleep duration, suggesting that longer nap sleep induces shorter nighttime sleep duration. Among the sleep arrangements, such as nighttime breastfeeding or co-sleeping, only nighttime breastfeeding predicted shorter nighttime sleep duration. Our findings indicate that shorter naps induce a longer nighttime sleep in 1.5-year-old toddlers while nighttime breastfeeding decreases their nighttime sleep duration.

Tension pneumoperitoneum caused by intestinal perforation from underlying colon cancer: a case report

Background

Tension pneumoperitoneum, a form of abdominal compartment syndrome, is an important clinical condition. Increased pressure in the intraperitoneal cavity leads to respiratory and circulatory instability. Most of the reported cases include complications due to active air infusion into the peritoneal cavity or trauma; however, few reports are available on tension pneumoperitoneum caused by perforation from colon cancer. We present a case of a patient with tension pneumoperitoneum caused by gastrointestinal perforation owing to colon cancer.

Case presentation

A 63-year-old Japanese man with altered mental state was brought to our emergency department. He was in shock, and an abdominal radiograph suggested gastrointestinal perforation. Despite rapid fluid infusion and inotropic support, his condition deteriorated. His abdomen was tensely distended; abdominal computed tomography showed significant intra-abdominal gas. Following immediate needle decompression, his circulatory status improved. Emergent laparotomy revealed an approximately 10-cm tumor (adenocarcinoma) in the colon, which caused the perforation.

Conclusions

A perforated wall or the surrounding omental fat that acts as a one-way valve could lead to tension pneumoperitoneum without active air infusion. Although tension pneumoperitoneum is a life-threatening condition, it is reversible if prompt diagnosis and immediate decompression are performed. Physicians should always consider this condition as one of the causes of shock or cardiopulmonary arrest, even without an apparent medical history of active air infusion or trauma.

Nipple Skin Trauma in Breastfeeding Women During Postpartum Week One

OBJECTIVE

To objectively describe changes to nipple skin and classify signs of nipple trauma in breastfeeding women during postpartum week 1.

METHODS

This study was conducted in two phases. Phase 1 was an observational prospective study of breastfeeding mothers in which data were obtained from photographs and digital images of nipple skin and analyzed to anatomically classify signs of nipple trauma. In Phase 2, the reliability of signs identified in Phase 1 was verified with the cooperation of eight clinical midwives.

RESULTS

A total of 776 images of 50 breastfeeding mothers were obtained daily. The signs of nipple trauma included erythema, swelling, blistering, fissure, and scabbing. Purpura and peeling were identified only with photographic image analysis. Scabbing and blistering were classified as damage to the dermis, and erythema and swelling as damage to the epidermis, based on anatomical evidence and the mothers' subjective experiences of pain intensity. Erythema and swelling were observed from day 0, with erythema most frequently observed. For inter-rater reliability of the five signs of nipple trauma, Kendall's coefficient of concordance ranged from 0.46 (moderate) to 0.85 (almost perfect). Reliability was high for fissure, substantial for blistering and scabbing, and moderate for erythema and swelling.

CONCLUSIONS

Image analysis revealed five signs of nipple trauma. Erythema and swelling were the most frequently observed signs during postpartum week 1. However, the agreement rate was lower than that for other signs, suggesting the possibility of conflicting interpretations in clinical evaluation.

Daytime nap controls toddlers' nighttime sleep

Previous studies have demonstrated that afternoon naps can have a negative effect on subsequent nighttime sleep in children. These studies have mainly been based on sleep questionnaires completed by parents. To investigate the effect of napping on such aspects of sleep quality, we performed a study in which child activity and sleep levels were recorded using actigraphy. The parents were asked to attach actigraphy units to their child’s waist by an adjustable elastic belt and complete a sleep diary for 7 consecutive days. 50 healthy young toddlers of approximately 1.5 years of age were recruited. There was a significant negative correlation between nap duration and both nighttime sleep duration and sleep onset time, suggesting that long nap sleep induces short nighttime sleep duration and late sleep onset time. We also found a significant negative correlation between nap timing and nighttime sleep duration and also a significant positive correlation between nap timing and sleep onset time, suggesting that naps in the late afternoon also lead to short nighttime sleep duration and late sleep onset. Our findings suggest that duration-controlled naps starting early in the afternoon can induce a longer nighttime sleep in full-term infants of approximately 1.5 years of age.

Relation between sleep status of preterm infants aged 1-2 years and mothers' parenting stress

BACKGROUND

The aim of this study was to compare infants' sleep measures through an actigraph and maternal parenting stress among preterm and full-term mothers, and to explore the factors affecting maternal parenting stress in relation to infants' sleep.

METHODS

The subjects were 44 pairs of mothers and children. Twenty-one were in the preterm group, and 23 were in the full-term group. Inclusion criteria for preterm infants were born at less than 36 weeks and birthweight of less than 2500 g. The Parenting Stress Index (PSI) Short Form assesses maternal perception of the degree of parenting stress: the children's domain, and the parent's domain. An actigraph was applied to assess the infants' sleep measures.

RESULTS

The PSI showed significant differences, with high scores in parenting stress in the preterm group. Also, the number of mothers who complained about their infant's sleep issues was significantly higher in the preterm group. Most of the sleep measures showed improvement by their age in both preterm and full-term infants. Multiple linear regression analysis showed that sleep efficiency, longest sleep duration at nighttime accounted for 71% of stress in the children's domain of the PSI of the preterm group.

CONCLUSION

The parenting stress among mothers of preterm infants was significantly higher than that of mothers of full-term infants. The mothers of preterm infants were concerned about their infant's nocturnal sleep quality.

[Development of nocturnal sleep behaviors in very low birth infants]

The objective of this study is to identify the developmental changes in nocturnal sleep behaviors among preterm infants in comparison with full-term infants (control group). The subjects were 18 preterm infants and 23 full-term infants with mean gestational weeks of 26.5 +/- 2.3 and 39.1 +/- 1.3, and average weights of 879 +/- 188 g and 2,940 +/- 352 g, respectively. Sleep measures were obtained through Actigraph (Micro-mini RC, Ambulatory Monitoring Inc., Ardsley, NY) over a week-long period. Results showed that the sleep duration was significantly different depending on the corrected age of months in only the preterm group (Preterm group: 504 +/- 55 min in under 12 months group, 543 +/- 68 min in over 13 months group. Full-term group: 548 +/- 68 min in under 12 months group, 544 +/- 79 min in over 13 months group). ACTX (percentage of minutes with higher than 0 activity score) was significantly higher for the preterm infants at both age groups in months. In conclusion, the nocturnal sleep duration of preterm infants reached the same level as those of full-term infants after the age of 13 corrected months. Also preterm infants were found to have a higher percentage of less restful sleep during nighttime. Further research is needed to understand the developmental course of physical activity during night time of preterm infants.

Comparing sleep measures of infants derived from parental reports in sleep diaries and acceleration sensors

AIM

Comparing sleep measures of infants derived from two data collection methods, acceleration sensors and sleep diaries, and identify the clinical application for each data collection method.

METHODS

The participants were 52 pairs of infants and mothers. Infant sleep measures were obtained through the actigraphs (Micro-mini RC, Ambulatory Monitoring Inc., Ardsley, NY, USA) and sleep diaries for over a period of 7 days.

RESULTS

The results showed that the concordance in sleep measures derived from two methods showed decreases in the following order: sleep offset time [r=0.91 (p=0.00)], sleep onset time r=0.89 (p=0.00), nocturnal sleep duration [r=0.75 (p=0.00)], the number of night wakings [r=0.46 (p<0.01)] and WASO [r=0.34 (p<0.05)]. It was revealed that the accuracy of sleep diary records was affected by the sleeping place and varied throughout the study period.

CONCLUSION

It was confirmed that the sleep measures indicating sleep schedule reported from the sleep diaries had high concordances compared with the data from the actigraphs. Using the sleep diary was recommended to understand behaviours when focusing on infant's daily rhythms. In terms of accuracy and stability of recording throughout the study period, understanding sleep quality and independence of sleeping places, the choice of actigraph was recommended.

Activity-based assessment of the sleep behaviors of VLBW preterm infants and full-term infants at around 12 months of age

PURPOSE

The aim of this study is to identify the characteristics of sleep behaviors assessed from activity data among very low-birth weight (VLBW) preterm infants in comparison to full-term infants at the age of around 12 corrected months, due to the possibility that sleep behaviors of preterm infants may be different from those of full-term infants.

METHOD

Cross-sectional study. Infant sleep measures were obtained through actigraphs (Micro-mini RC, Ambulatory Monitoring Inc., Ardsley, NY), which were attached to the infants' ankles during a week-long period. The subjects were 14 preterm infants and 14 full-term infants in which the mean ages were 13.3+/-2.1 corrected months and 12.3+/-2.4 month, respectively.

RESULTS

Preterm infants showed significantly less sleep duration during nighttime than full-term infants. The mean activity score and ACTX (Activity Index: percentage minutes with more than 0 activity score) of preterm infants during nighttime were significantly higher than those of full-term infants. No significant differences in total sleep duration, daytime sleep duration, the number of night-wakings, and sleep efficiency were found between the two groups.

CONCLUSION

Preterm infants slept less and had a larger percentage of less restful sleep during nighttime. The results indicated that prematurity at the time of birth remained throughout the developmental course of sleep behaviors among preterm infants at around the age of 12 corrected months.

Ischemia-reperfusion injury of the cochlea: effects of an iron chelator and nitric oxide synthase inhibitors

Release of free iron from cellular stores and activation of nitric oxide synthase (NOS) has been implicated in a wide variety of cochlear injuries. In order to evaluate the effects of deferoxamine (a iron chelator), 3-bromo-7-nitroindazole (a relatively selective neuronal NOS (nNOS) inhibitor) or aminoguanidine (a relatively selective inducible NOS (iNOS) inhibitor) on the post-ischemic cochlear dysfunction, albino guinea pigs were subjected to 30 min ischemia, and the threshold shifts of the compound action potential (CAP) from pre-ischemic values were compared with those of control animals 4 h after the onset of reperfusion. A statistically significant reduction in the post-ischemic CAP threshold shift was observed in the animals treated with deferoxamine or 3-bromo-7-nitroindazole. However, aminoguanidine did not affect the post-ischemic CAP threshold shift. These results suggest that free iron and nNOS play deleterious roles in the cochlear injury induced by transient ischemia.

Effect of three flavonoids, 5,7,3',4'-tetrahydroxy-3-methoxy flavone, luteolin, and quercetin, on the stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophil

The effect of three flavonoids, 5,7,3',4'-tetrahydoxy-3-methoxy flavone (THMF), luteolin, and quercetin, on the stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophils were investigated. When the cells were preincubated with these flavonoids, the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was significantly suppressed, showing a dependence on amounts of the flavonoid. The suppressing effect of the flavonoid was THMF > luteolin > quercetin. These flavonoids also suppressed the superoxide generation induced by phorbol 12-myristate 13-acetate. In this case also, THMF was more effective than luteolin and quercetin. On the other hand, the superoxide generation induced by arachidonic acid was markedly suppressed by quercetin. The suppressing effect was quercetin >> THMF > luteolin. THMF, luteolin, and quercetin significantly suppressed tyrosyl phosphorylation of 80.1-, 58.0-, and 45.0-kDa proteins in fMLP-treated human neutrophils. The suppression depended on the concentration of the flavonoids, and the inhibition of tyrosyl phosphorylation was in parallel to that of the fMLP-induced superoxide generation, respectively. While luteolin and quercetin showed a weak hemolytic activity at 2.5 mM, THMF showed almost no hemolytic activity even at 5 mM, suggesting an advantage of THMF for its clinical use.

Medial septal microinfusion of scopolamine disrupts hippocampal activity and trace jaw movement conditioning

This study investigated the effects of microinfusion of scopolamine into the medial septum (MS Scp) on hippocampal neurophysiology and learning of the rabbit's classically conditioned jaw movement response. The percentage of hippocampal theta slow waves (2-8 Hz) decreased after drug infusion in the MS Scp group but did not change in control groups that received infusion of saline into the MS or scopolamine into the cortex. Unit recordings from the MS Scp group showed significantly smaller conditioning-related hippocampal neural responses than seen in controls, and during conditioning, rabbits in the MS Scp group took significantly longer to reach learning criterion than either control group. Thus, the neural and behavioral impairments previously reported for systemic muscarinic blockade were reproduced by microinfusions restricted to the medial septal nucleus.

Medial septal microinfusion of scopolamine disrupts hippocampal activity and trace jaw movement conditioning

This study investigated the effects of microinfusion of scopolamine into the medial septum (MS Scp) on hippocampal neurophysiology and learning of the rabbit's classically conditioned jaw movement response. The percentage of hippocampal theta slow waves (2-8 Hz) decreased after drug infusion in the MS Scp group but did not change in control groups that received infusion of saline into the MS or scopolamine into the cortex. Unit recordings from the MS Scp group showed significantly smaller conditioning-related hippocampal neural responses than seen in controls, and during conditioning, rabbits in the MS Scp group took significantly longer to reach learning criterion than either control group. Thus, the neural and behavioral impairments previously reported for systemic muscarinic blockade were reproduced by microinfusions restricted to the medial septal nucleus.

Scopolamine disruption of behavioral and hippocampal responses in appetitive trace classical conditioning

Twelve young rabbits (3-6 months; Oryctolagus cuniculus) were classically conditioned in a trace jaw movement paradigm (300 ms tone, 450 ms trace, 200 ms intraoral water) after implantation of electrodes into area CA1 of dorsal hippocampus. Rabbits were divided into two groups and administered either 0.5 mg/kg scopolamine hydrobromide (HBr) or 0.5 mg/kg scopolamine methylbromide (MBr) subcutaneously before daily training sessions. Rabbits given HBr took significantly more trials to reach a behavioral criterion of eight conditioned responses in any nine consecutive trials than rabbits given MBr (P = 0.03). Conditioned, but not unconditioned, rhythmic jaw movement responses of the HBr group were of a lower frequency (Hz) than those of MBr rabbits (P = 0.02). The magnitude of hippocampal conditioning-related responses across the first 3 days of training was significantly smaller for HBr rabbits than for MBr rabbits (P = 0.02). These effects of central cholinergic blockade are similar to those reported for undrugged aging rabbits trained in the same paradigm (Seager MA, Borgnis RL, Berry SD. Neurobiol. Aging 1997;18(6):631 639).

Localization of xenobiotic-responsive element binding protein in rat hepatocyte nuclei after methylcholanthrene administration as revealed by in situ Southwestern hybridization

Xenobiotic-responsive element binding protein (XRE-BP), a heterodimer of aryl hydrocarbon receptor (AhR) and its nuclear translocator (Arnt), regulates the transcription of cytochrome P-450 1A1 gene (CYP1A1) through XRE in response to xenobiotic inducers. For a better understanding of the regulatory mechanism of CYP1A1 through XRE, localization of XRE-BP was examined in liver sections or isolated hepatocyte nuclei from control and 3-methylcholanthrene (MC)-treated rats by in situ Southwestern hybridization, using synthetic XRE as a probe, and was observed by confocal laser scanning microscopy and electron microscopy. Gel mobility shift assay and competitive binding assay showed specificity of the synthetic XRE probe. XRE-BP was exclusively localized in hepatocyte nuclei in liver sections from animals 3 hr after MC injection, whereas the protein was absent in hepatocyte cytoplasm in MC-treated animals and in hepatocyte nuclei and cytoplasm in control animals. In isolated hepatocyte nuclei, XRE-BP began to accumulate in the central region between 0.5 and 3 hr, showed a peak between 3 and 6 hr, decreased gradually between 6 and 72 hr, and disappeared at 72 hr after MC injection. The protein was scarce in peripheral and nucleolar regions of the nucleus. Therefore, XRE-BP is formed in the nuclei of hepatocytes after MC stimulation. In addition, XRE-BP was found in isolated hepatocyte nuclei from control animals after preincubation with cytoplasmic lysate from MC-treated animals, although the protein was absent in the nuclei before the preincubation. These findings strongly suggest that AhR translocates from hepatocyte cytoplasm to the nucleus and forms XRE-BP in the nucleus after MC stimulation.

Quantitative analysis of endoplasmic reticulum and cytochrome P-450 in hepatocytes from rats injected with methylcholanthrene

To examine whether the smooth endoplasmic reticulum (SER) proliferates in hepatocytes from animals treated with methylcholanthrene (MC) frequently used as an inducer for the enzymes of the microsomal mono-oxygenase system, we estimated the area of (smooth and rough) ER per unit cytoplasmic volume by morphometry in periportal, midzonal and perivenular hepatocytes from rats injected with 25 mg/kg MC once a day for 3 days. In addition, immunostaining intensity of major MC-inducible cytochrome P-450 (P-450) forms (1A1/1A2) and total P-450 content in the cytoplasm of hepatocytes in the three zones were measured by microphotometry to ascertain whether P-450 is sufficiently induced in each sublobular zone by the administration. In spite of significant increase in the staining intensity of P-450 1A1/1A2 and amount of total P-450, the proliferation of SER (and RER) did not occur in the three-zone hepatocytes from rats injected with MC. In perivenular hepatocytes, constitutive forms of P-450 other than 1A1/1A2 decreased (to 10%) instead of marked increase in P-450 1A1/1A2 (about 20 times), while the constitutive forms decreased to 50% in midzonal hepatocytes and remained unchanged in periportal hepatocytes after MC administration. In addition, the present results show divergence between biochemical and immumohistochemical results previously reported on MC-inducible P-450 after MC administration to be due primarily to a curvilinear relationship between content and intensity.

Emerin, deficiency of which causes Emery-Dreifuss muscular dystrophy, is localized at the inner nuclear membrane

X-linked recessive Emery-Dreifuss muscular dystrophy (EDMD) is an inherited muscle disorder characterized by the clinical triad of progressive wasting of humero-peroneal muscles, early contractures of the elbows, Achilles tendons and postcervical muscles, and cardiac conduction block with a high risk of sudden death. The gene for EDMD on Xq28 encodes a novel protein named emerin that localizes at the nuclear membrane of skeletal, cardiac and smooth muscles and some other non-muscle tissues. To investigate a possible physiological role for emerin, we examined the ultrastructural localization of the protein in human skeletal muscle and HeLa cells, using ultrathin cryosections. We found that the immune-labeled colloidal gold particles were localized on the nucleoplasmic surface of the inner nuclear membrane, but not on the nuclear pore. Emerin stayed on the cytoplasmic surface of the nuclear lamina, even after detergent treatment that solubilizes membrane lipids and washes out membrane proteins. These results suggest that emerin anchors at the inner nuclear membrane through the hydrophobic stretch, and protrudes from the hydrophilic region to the nucleoplasm where it interacts with the nuclear lamina. We speculate that emerin contributes to maintain the nuclear structure and stability, as well as nuclear functions, particularly in muscle tissues that have severe stress with rigorous contraction-relaxation movements and calcium flux.

Relationship between immunostaining intensity and antigen content in sections

We studied the relationship between staining intensity of immunohistochemical reaction and antigen content in sections. Alpha-fetoprotein (AFP) and albumin in sections cut from livers of newborn, 5-, 10-, 20-, and 60-day-old rats were examined as examples. First, we compared average immunostaining intensity (sum of specific absorbance in pixel/number of pixels) measured by image processing (IP), with antigen content measured by immunochemical assay to determine whether the intensity is proportional to antigen content. The intensity of AFP was proportional to the antigen content, whereas that of albumin was not. Subsequently, the antigen preservation test was carried out to determine whether the intensity was decreased by fixation and, if so, which type of decrease (proportional or disproportionate) occurred. Thereafter, antigen content in the same portion in the same immunostained section was measured by the microphotometric (MP) method followed by the IP method, because the MP method gives a low average antigen content when a decrease in antibody binding occurs in sections, whereas the average antigen content measured by the IP method is unchanged. The intensity of AFP decreased primarily by a proportional decrease in antigenicity during fixation. However, the intensity of albumin decreased not only by a proportional decrease during fixation but also by a disproportionate reduction in antibody binding during immunostaining or before fixation. The results indicate that AFP content in sections is measurable by quantitative immunohistochemical methods, whereas albumin content is not.

Peri- and postnatal changes in reduced nicotinamide adenine dinucleotide phosphate-cytochrome P-450 reductase content in hepatocytes of rats

To study the process of the expression of reduced nicotinamide adenine dinucleotide phosphate-cytochrome P-450 reductase (EC 1.6.2.4) in the liver during development, the amount of enzyme in the cytoplasm of periportal and perivenular hepatocytes in sections cut from livers of male rats was measured during peri- and postnatal growth by quantitative immunohistochemistry with a video image processor. In livers of 19-day-old foetuses, the reductase content in the cytoplasm of periportal and perivenular hepatocytes was 0.16 microM and 0.20 microM, respectively. From the 19th day of gestation to 5 days after birth, the enzyme content increased markedly in the cytoplasm of periportal (288%) and perivenular hepatocytes (301%). Subsequently, the content in the cytoplasm of periportal hepatocytes increased slightly (46%) from 5 to 20 days of age, remained unchanged from 20 to 45 days of age, and increased slightly (15%) from 45 to 90 days of age. However, the content in the cytoplasm of perivenular hepatocytes increased progressively (125%) between 5 and 90 days of age. Thus, the amount of cytochrome P-450 reductase increases markedly in periportal and perivenular hepatocytes during the perinatal period, and subsequently the enzyme content increases gradually in periportal hepatocytes and progressively in perivenular hepatocytes. The present results also suggest that the divergence between cytochrome P-450 expression and the cytochrome P-450-dependent drug metabolic activity in hepatocytes during the perinatal period, found in previous studies, can be attributed to a low cytochrome P-450 reductase density in the membrane of endoplasmic reticulum of periportal and perivenular hepatocytes.

Preparation of liposomes that mimic the membrane of endoplasmic reticulum of rat hepatocytes

To examine the interaction between biomembranes and membrane-bound proteins, large unilamellar liposomes have been required. In the present study, we prepared liposomes from a mixture of phospholipids having a phospholipid composition similar to that in the endoplasmic reticula (microsomes) of rat hepatocytes by eight different methods. The resulting liposomes were examined by a combination of the freeze-fracture-replica procedure with biochemical methods. The freeze-thawing method of Pick (1981) gave the best results; large unilamellar liposomes that mimic the membrane of endoplasmic reticulum were obtained. Liposomes made by this method are thus suitable for analysis of the interaction between the endoplasmic reticulum membrane and membrane-bound proteins.

Endoplasmic reticulum proliferates without an increase in cytochrome P-450 in hepatocytes of mice treated with phenobarbital and cobalt chloride

To determine whether endoplasmic reticulum (ER) proliferation in hepatocytes after phenobarbital (PB) administration relates closely to cytochrome P-450 (P-450) increase, we have measured the amount of total P-450 per unit cytoplasmic volume (P-450 content) by microphotometry and estimated the area of ER per unit cytoplasmic volume (ER area) by morphometry in periportal, midzonal, and perivenular hepatocytes of mice injected daily with PB (100 mg/kg), or with PB (100 mg/kg) plus cobalt chloride (50 mg/kg) for three days. After injection of PB, the P-450 content and ER area increased in hepatocytes of the three sublobular zones. In mice treated with PB plus cobalt chloride, however, the ER area increased, but the P-450 content decreased or remained unchanged in hepatocytes of the three zones. We conclude that cobalt chloride inhibits the increase in total P-450 but has no effect on the proliferation of ER of hepatocytes in mice treated with PB, indicating a dissociation of ER proliferation and P-450 increase after administration of PB.

Location of light-repressible, small GTP-binding protein of the YPT/rab family in the growing zone of etiolated pea stems

YPT/rab proteins are ras-like small GTP-binding proteins that serve as key regulators of vesicular transport. The mRNA levels of two YPT/rab genes in pea plants are repressed by light, with the process mediated by phytochrome. Here, we examined the mRNA expression and the location of the two proteins, pra2- and pra3-encoded proteins, using monoclonal antibodies. The pra2 and pra3 mRNA levels were highest in the stems of dark-grown seedlings. The corresponding proteins were found in the cytosol and the membranes of the stems. Most of the pra2 protein was in the growing internodes, especially in the growing region, but the pra3 protein was widespread. These results suggest that the pra2 protein is important for vesicular transport in stems, possibly contributing to stem growth in the dark, and that the pra3 protein is important for general vesicular transport. The amounts of pra2 and pra3 proteins decreased with illumination. The decrease in these proteins may be related to the phytochrome-dependent inhibition of stem growth that occurs in etiolated pea seedlings.

Isolation, characterization and expression of cationic peroxidase isozymes released into the medium of cultured tobacco cells

Three glycoproteins of 34, 38 and 40 kDa were isolated from the spent medium of suspension-cultured tobacco cells. The 38-kDa and 40-kDa proteins were highly cationic peroxidases with indistinguishable enzymic properties but their structural difference was confirmed by sequence analysis of the amino-terminal regions and the recognition specificity of monoclonal antibodies. The 34-kDa protein was a moderately cationic peroxidase with enzymic properties quite different from those of the 38-kDa and 40-kDa enzymes. They were undetectable in the spent medium during the cell-proliferation phase but became abundant in the medium during the cell-expansion phase. This was confirmed quantitatively with the 40-kDa protein using the 40-kDa-specific monoclonal antibody. The mRNA expression for 40-kDa protein was at a constant basal level in the cell-proliferation phase but increased in the cell-expansion phase.

Measurement of NADPH-cytochrome P-450 reductase content in rat liver sections by quantitative immunohistochemistry with a video image processor

We have a quantitative light microscopic immunohistochemical method using video image processing. First, an antigen (NADPH-cytochrome P-450 reductase) content in homogenates of livers of rats was measured by enzyme immunoassay. Then frozen sections from rat livers were incubated with the anti-NADPH-cytochrome P-450 reductase antibody under saturation conditions by the indirect immunoperoxidase method. Subsequently, relative staining intensities in small portions and those in wide areas in the sections were measured with a video image processor. Finally, the resulting relative values obtained from the small portions were converted into absolute NADPH-cytochrome P-450 reductase contents using the results of enzyme immunoassay and the average relative staining intensity obtained from the wide areas in the sections. The reductase content in sections from rat livers measured by the image processing method coincided with the content measured by the microphotometric method using a nitrocellulose model system. The present image processing method is applicable to measurement of contents of antigens that can not be immobilized in model systems.

Significance of high glucose-6-phosphatase activity in rat oviduct epithelium

To study the origin of glucose in the oviduct fluid, we cytochemically examined glucose-6-phosphatase (G6Pase) activity in rat oviduct. The activity in the whole oviduct was also assayed biochemically. During proestrous, estrous, and metestrous phases, staining reaction for the activity was moderate in the epithelium of the caudal isthmus (CaI) and uterotubal junction (UJ), whereas it was weak in that of the ampulla (A) and cephalic isthmus (CeI). In the diestrous phase, staining reaction in the epithelium of CaI and UJ became strong although it remained weak in that of A and CeI. Reaction product for the activity was localized in the endoplasmic reticulum and nuclear envelope of all cell types in the epithelium. The amount of reaction product in secretory cells was small to moderate in CaI and UJ, and small in A and CeI during proestrus, estrus, and metestrus. In diestrous the amount became abundant in CaI and UJ and moderate in A and CeI. However, the amount in ciliated cells remained small in the four segments during the four phases. The biochemical activity in diestrous was greater than that in proestrus, estrus, or metestrus. This shows that the activity is high in secretory cells in the epithelium of CaI and UJ in the diestrous phase and suggests that the role of the high activity is to release glucose into the oviduct fluid for use by the embryo passing down the CaI and UJ to the uterus.

Waldenström's macroglobulinemia associated with amyloidosis and membranous nephropathy

A 61-year-old man with massive proteinuria and hyper gamma-globulinemia was admitted to hospital because of massive edema and pulmonary infection. He showed significantly high level of serum IgM (3244 mg/dl) with lambda-type M-protein and Bence Jones protein detected by immunoelectrophoresis. Renal biopsy specimen showed not only the diffuse amorphous amyloid deposition in mesangial area but global thickening of capillary wall with spike formation by silver staining which was similar to the spicular formation. Immunofluorescence disclosed find granular deposition of IgG and C3 along the capillary wall and the electromicroscopic findings clearly showed both massive amyloid fibril at mesangial area and diffuse epimembranous electron dense deposits. lambda-type Bence Jones protein in macroglobulinemia was suggested not only the cause of renal amyloidosis but also the antigenic origin of membranous nephropathy in this case.

Postnatal development and sublobular distribution of cytochrome P-450 in rat liver: a microphotometric study

To study the process of expression of cytochrome P-450 (P-450) in hepatocytes during development, we measured microphotometrically the P-450 content in periportal and perivenular hepatocytes of male rats during peri- and postnatal growth. From Day 19 of gestation to Day 5 after birth, P-450 content in both periportal and perivenular hepatocytes increased markedly (periportal 1046%; perivenular 819%). The content in periportal hepatocytes remained unchanged from 5 to 20 days of age, and increased slightly (24%) from 20 to 45 days of age. However, the content in perivenular hepatocytes increased progressively (105%) between 5 and 45 days of age. The difference in P-450 content became apparent between periportal and perivenular hepatocytes after 7 days of age. The content in periportal or perivenular hepatocytes reached the adult level at 45 days of age. Therefore, the perinatal period is the time at which a marked increase in P-450 occurs in hepatocytes throughout the liver lobule. The subsequent period before weaning is the time at which the sublobular heterogeneous distribution of P-450 appears. The period after weaning is the time at which a slight increase in P-450 content in periportal hepatocytes and a marked increase in the enzyme in perivenular hepatocytes takes place.

Densities of NADPH-ferrihemoprotein reductase and cytochrome P-450 molecules in the endoplasmic reticulum membrane of rat hepatocytes

In hepatocytes, NADPH-ferrihemoprotein reductase (reductase) has been hypothesized to exist as aggregates or micelles in endoplasmic reticulum (ER) membrane. However, if the number of reductase molecules per unit area of ER is low, this hypothesis cannot explain how a few reductase molecules efficiently reduce many P-450 molecules. To test this hypothesis, we estimated the numbers of reductase and P-450 molecules per unit ER area (reductase and P-450 densities) by microphotometry of the two enzymes in conjunction with morphometry of ER in periportal, midzonal, and perivenular rat hepatocytes. The reductase density in periportal, midzonal, and perivenular hepatocytes (107-179 molecules/microns 2 of ER) was high enough to efficiently reduce all P-450 molecules in the ER, although the value in perivenular hepatocytes was lowest owing to the relatively greater amount of ER in this region. The pattern of sublobular gradient in the reductase density was similar to that in the P-450 density. Consequently, the molar ratio of P-450 to reductase in ER was similar (about 40:1) in hepatocytes regardless of their positions within the liver lobule.

Postnatal changes in sublobular distribution of NADPH-cytochrome P-450 reductase in rat liver

Immunohistochemical distribution of NADPH-cytochrome P-450 reductase (NADPH-ferrihaemoprotein reductase; EC 1.6.2.4.) in the liver lobule was examined during development of the rat. From the 19th day of gestation to 4 days after birth, the enzyme was distributed uniformly throughout the lobule. The immunostaining for the enzyme was weak before birth, and became slightly stronger after birth. A slightly uneven distribution of immunoreactivity, stronger in perivenular zones, appeared at 5 days after birth. Then, the staining intensity in perivenular zones became progressively stronger with age, except for a slight increase between 10 and 20 days of age. The intensity in periportal zones also increased gradually, although it remained weaker than that in perivenular zones. Around 30 days of age, the distribution of the immunostaining, stronger in perivenular than in periportal zones, was similar to that seen in the lobules of adult animals. Thus, heterogeneity among hepatocytes with respect to the enzyme content is not present in fetal and newborn rats but develops gradually during postnatal development; the postnatal growth of the liver is accompanied by a change in the pattern of the distribution of this enzyme within the lobule.

Relation between cytochrome P-450 increase and endoplasmic reticulum proliferation in hepatocytes of mice treated with phenobarbital: a microphotometric and morphometric study

To obtain detailed information on phenobarbital (PB)-induced cytochrome P-450 (P-450) increase and endoplasmic reticulum (ER) proliferation in hepatocytes, we estimated microphotometrically the amount of P-450 per unit cytoplasmic volume and morphometrically the area of ER per unit cytoplasmic volume in hepatocytes adjacent to the portal area or central venule (1 periportal or 1 perivenular cells) and in the second and third layers from the portal area or central venule (2, 3 periportal or 2, 3 perivenular cells) from mice injected with 35, 50, 100, or 150 mg/kg PB once a day for 3 days. By dividing the P-450 amount by the ER area, the number of P-450 molecules per unit ER area was also calculated. In 1 and 2, 3 perivenular cells, except for 2, 3 perivenular cells after injection of 150 mg/kg PB, the amount of P-450 increased with ER proliferation and the number of P-450 molecules in ER remained unchanged after injection of 50, 100, or 150 mg/kg PB. In 2, 3 periportal cells, however, the P-450 amount and the number of P-450 molecules in ER increased markedly without or with some ER proliferation after injection of 50, 100, or 150 mg/kg PB; the P-450 increase appears to be generally independent of ER proliferation. The 1 periportal cells are probably exceptional hepatocytes that usually did not respond to PB stimulation.

High glucose-6-phosphatase activity in non-pigmented epithelial cells of rabbit ciliary body

For study of the origin of glucose in the aqueous humor, glucose-6-phosphatase (G6Pase) and hexokinase activities, and glycogen, were cytochemically examined in the ciliary body (CB) of rabbit. G6Pase activity was also assayed biochemically. The staining reaction for G6Pase activity was strong in the non-pigmented epithelium (NPE) in the pars plana and tips of ciliary processes in the region containing large ciliary pockets within the pars plicata. NPE cells contained abundant reaction product for G6Pase activity in the endoplasmic reticulum (ER) and nuclear envelope. However, NPE in other regions of the CB and pigmented epithelium (PE) of CB, and other areas surrounding the anterior and (PE) of CB, and other areas surrounding the anterior and posterior chambers, showed weak or no G6Pase staining reaction. Biochemical G6Pase activity in the whole ciliary body was relatively high. Both NPE and PE in the pars plana and the tips showed strong staining reaction for hexokinase activity but no staining for glycogen. Furthermore, NPE cells in the tips bore large aggregates of smooth ER and many Golgi apparati. These suggest that the high G6Pase activity in NPE cells in the pars plana and the tips is related to glucose release into the aqueous humor.

Prediction of curve progression in idiopathic scoliosis based on initial roentgenograms. A proposal of an equation

A retrospective study was conducted in 122 patients with idiopathic scoliosis who were followed for more than 2 years. There were 58 patients who showed 5 degrees (Cobb) or more progression, and 41 patients who showed no progression. Only those who did not receive any treatment or who failed to comply with brace treatment were selected, to eliminate the effect of treatment. In the early phase of the study, 12 parameters were put into a multivariate analysis to observe the relative weight of each of them, which led the authors to eliminate the following five parameters: 1) Cobb angle, 2) rotation of the apical vertebra, 3) deviation of the apical vertebra, 4) Risser's expected correction: (standing angle--supine angle) X 3, and 5) maturation index of the iliac apophysis. Through a multiple regression analysis, an equation was obtained to correlate the predictive and the real progression within 10 degrees deviation.

Inhibitory effect of phenobarbital on peroxisome biogenesis in mouse hepatocytes

Peroxisomes in hepatocytes from mice administered 35, 50, or 100 mg/kg of phenobarbital (PB) were analyzed by quantitative electron microscopy. In perivenular hepatocytes, the volume of peroxisomes per unit cytoplasmic volume decreased to 78 or 57% of that of control animals by administration of 50 or 100 mg/kg. Their average volume also decreased to 78 or 64% of that in control animals in animals injected with 35 or 50 mg/kg. Further, cytochemical catalase activity appeared decreased in peroxisomes of hepatocytes of this zone after administration of 50 or 100 mg/kg. These suggest an inhibitory action of PB administration of biogenesis of peroxisomes in perivenular hepatocytes. In periportal hepatocytes, however, the volume density, average volume, and cytochemical catalase activity of peroxisomes did not change by administration of any doses of PB. Thus, PB administration appears to produce no inhibitory effect on the peroxisome biogenesis in periportal hepatocytes. On the other hand, the number of peroxisomes per unit cytoplasmic volume increased in both periportal and perivenular hepatocytes in animals injected with 50 mg/kg, although it returned to the level of control animals by injection of 100 mg/kg. The inhibitory effect of PB on the peroxisome neogenesis in perivenular hepatocytes may be related to the marked smooth endoplasmic reticulum proliferation by administration of this drug.

[Follow-up results of brace treatment of adolescent idiopathic scoliosis]

Assessment of brace treatment for idiopathic scoliosis should be based on long-term follow-up results compared with those in untreated cases. Such comparison, however, is extremely difficult from an ethical standpoint. Therefore, we conducted a comparable follow-up study on three groups of patients divided according to how well the brace had been worn during the period of treatment. Two hundred and twenty-six adolescent idiopathic cases in which brace treatment had been initiated before skeletal maturity were studied, 170 of which were followed up after the termination of the treatment. In 131 single curve cases, those who had worn the brace well showed significantly less progression than those who had worn it poorly, while 38 double curve cases failed to show significant difference between the two groups. Approximately two thirds of the cases demonstrated no major progression whether the brace had been worn well or not. Development of a method to select cases based on prediction of curve progression is an important project in the near future.

[Idiopathic scoliosis and equilibrium disturbance (author's transl)]

The body balance is maintained by the complexed nervous system in the brain stem and the cerebellum. However, the amount of neurological information obtained from this area is relatively small, so that a fine abnormality is easily overlooked or could not be definitely elicited. Examination of the ocular movement becomes often a powerful tool to detect an indiscrete lesion in the brain stem and the cerebellum which otherwise fails to be demonstrated neurologically.

METHOD

With a hypothesis that equilibrium disturbance might be playing a role in the development of idiopathic scoliosis, extensive neuro-otological studies were carried out in three groups of individuals: 169 cases of idiopathic scoliosis, 19 cases of congenital scoliosis and 488 young girls with no scoliosis. The examination included Mann's test, deviation tests and other neuro-otological tests with the special reference to the observation of the ocular movement.

RESULTS

1. There was no case in the entire groups which presented positive Mann's test or deviation abnormality. 2. With the aid of electronystagmography (ENG), the presence of nystagmus was detected in 71 out of 169 cases (42.0%) with idiopathic scoliosis, 9 out of 19 cases (46.7%) with congenital scoliosis and 5 out of 488 girls (1.0%) with no scoliosis. This fact was highly suggestive of the possibility of equilibrium disturbance in the background of scoliosis. 3. However, even with positive ENG findings, few cases showed abnormality on optokinetic nystagmus (OKN) test or eye tracking test, so that definite localization of the lesion was impossible in the majority of the cases with the abnormal ocular movement. 4. There was no significant correlation between the rate of the abnormal ocular movement and the age of the patient, the magnitude of the spinal curve or the curve pattern.

CONCLUSION

The co-existence of abnormal ocular movement and scoliosis was proved to be statistically significant, suggesting that equilibrium disturbance might be playing a role in the multifactorial etiology of idiopathic scoliosis, although the real pathomechanism still remains to be studied.