Polysynaptic neuronal pathways from group I and group II afferents innervating tail muscles to hindlimb motoneurons in the cat

Postsynaptic potentials evoked in motoneurons innervating m. posterior biceps and semitendinosus (PBSt) and m. triceps surae (GS) by low threshold afferents from various tail muscles located at the level of the second-third caudal vertebrae were investigated in the non-anesthetized and spinalized cat. Afferent inputs from tail muscles on both sides predominantly evoked depolarizing potential in PBSt motoneurons and hyperpolarizing potential in GS motoneurons. The findings suggest that in general, tail muscle afferents facilitate flexor and inhibit extensor hindlimb motoneurons through polysynaptic pathways, so that the pelvic girdle is kept in a low position to maintain the stability of the body irrespective of different movements or posture of the tail.

Effect of estrogen on the development of disuse atrophy of bone and muscle induced by tail-supension in rats

Rat tail-suspension induces disuse atrophy of muscles and bones in hindlimbs. In the present investigation we studied how ovariectomy and estrogen substitution affect the development of the disuse atrophy induced by suspension. Five-week old female Wistar rats were ovariectomized and divided into two groups. One group received intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received a vehicle injection (OVX group). After the third injection, each group was further divided into two groups, tail-suspended and non-suspended. After 7 days of tail-suspension, a significant decrease in the wet weight of femurs and their Ca and Pi content was observed in the OVX group. However, no significant change in those parameters was observed in the E2 group. In both E2 and OVX groups, a significant decrease in the wet weight of soleus and gastrocnemius muscles was demonstrated after the suspension. This demonstrated that estrogen administration to ovariectomized rats prevents the development of disuse bone atrophy but not that of muscle atrophy, suggesting that estrogen plays important roles in bone remodeling.

Administration of bisphosphonate prevents disuse bone atrophy induced by tail suspension

We recently demonstrated that osteopenia induced by rat tail-suspension was associated with an initial increase in bone resorption. To study the significance of the increase in early bone resorption for osteopenia, we investigated whether administration of YH529, a third-generation bisphosphonate, prevents the development of osteopenia as evidenced by increased wet weight of the femur, together with its calcium and phosphorus contents, when compared with those of tail-suspended rats treated with the vehicle alone. These results suggested that the initial increase in bone resorption plays an important role in the development of osteopenia induced by tail suspension.

A phase II study of high-dose epirubicin (EPI) plus cyclophosphamide (CPA) with G-CSF for breast cancer patients with visceral metastases or hormone-independent tumors: a trial of the Japan Clinical Oncology Group

To evaluate the efficacy and toxicity of high-dose epirubicin (EPI) plus cyclophosphamide (CPA) therapy, a phase II study of EPI, 130 mg/m2, plus CPA, 1000 mg/m2, with G-CSF every 3 weeks was carried out for 51 advanced or recurrent breast cancer patients by the Japan Clinical Oncology Group (JCOG). Fifty out of the 51 patients who were eligible for our criteria were treated with this regimen as first-line chemotherapy for visceral metastases or hormone-independent tumors. In this trial, 203 cycles were administered with an average of four cycles per patients. In 50 patients who were evaluable for response, there were 7 complete (CR) and 25 partial responses (PR) with an overall response rate of 64% (95% confidence interval, 50.1-75.9%). Symptomatic and hematological acute toxicity more than grade 3 occurred frequently; however, no treatment-related death occurred. The incidence of toxicities (> or = grade 3) was as follows: leukopenia 98%, thrombocytopenia 42%, nausea/vomiting 56% and hair loss 12%. In each cycle, daily administration of 2 micrograms/kg G-CSF (granulocyte-colony stimulating factor) was given on days 2-15 subcutaneously. The incidence of cardiotoxicity was low. Arrhythmia (< or = grade 2) was observed in 8% and a slight decrease of ejection fraction index (< or = grade 2) was observed in 2% in this trial. The median follow-up period for patients was 37.2 (24.6-51.5) months and the median survival period was 17.4 months. These data indicate that high-dose EPI + CPA combination chemotherapy was effective and well tolerated for breast cancer patients with visceral metastases or hormone-independent tumors. A randomized trial of high-dose EPI vs conventional chemotherapy is required to ascertain the usefulness of this regimen.

Effect of bisphosphonate administration on the excretion of stress hormones in tail-suspended rats

We demonstrated that administration of a bisphosphonate, YH529, prevents the development of disuse atrophy of the hind limbs induced by tail-suspension in rats. Since tail suspension is accompanied by an increase in the secretion of stress hormones, we studied whether administration of bisphosphonate affects the secretion of stress hormones during that procedure. Tail suspension was carried out in a metabolic cage by connecting a wire inserted through tail bone to the ceiling of the cage. The control rat received the same treatment but was not suspended. YH529 or a vehicle (PBS=phosphate buffered saline) was administered daily starting 3 days before the commencement of tail suspension. Urine samples were collected before the wire was inserted (day 0), on the day of insertion (day 1) and 3, 5 and 7 days after. In the control rats receiving PBS, urinary excretion of corticosterone and epinephrine did not change throughout the 7-day experimental period. In the control rats receiving YH529, urinary excretion of corticosterone increased significantly on the day of tail-piercing and wiring but then returned to the prior level. This increase was not observed in the control group receiving PBS. In the tail suspended rats, excretion of corticosterone and epinephrine increased significantly in both PBS and YH529 groups, the highest level being observed on the first day of tail suspension. Although statistically not significant, corticosterone excretion on day 1 of tail suspension was higher in the YH529 groups than that in the PBS group. It is thus suggested that administration of YH529 causes an augmented response to stress load.

A new double lumen balloon catheter for retrograde cerebral perfusion via jugular vein cannulation

A new catheter for retrograde cerebral perfusion (RCP) was developed that can be used to deliver blood directly into the internal jugular vein (IJV) beyond the venous valves at the jugular-subclavian junction and prevent blood from draining into the lower half of the body. This catheter can be inserted into the IJV via a standard puncture technique by use of a 14 Fr sheath. The catheter shaft has two channels for balloon inflation and blood perfusion, respectively. A balloon for occlusion of drainage veins (superior vena cava and azygos vein) is installed at the catheter tip. Side holes, through which oxygenated cold blood is delivered into the IJV, are located 95 mm from the catheter tip. In a mock circulatory study, the pressure at the perfusion line (16-118 mmHg) increased with the increasing flow rate (0-400 ml/min). In clinical application, under circulatory arrest with profound hypothermia, inflation of the balloon effectively reduced blood drainage into the lower half of the body and, consequently, RCP was successfully performed (flow rate, 300-350 ml/min; pressure at the IJV, 15 mmHg). Because all of these procedures were controlled from outside the operative field, RCP by use of this catheter could be useful in distal arch replacement via left lateral thoracotomy.

Experimental study of combination of extraaortic balloon counterpulsation and ventricular assist cup to acute heart failure in dogs

The goal of this study is to evaluate the applicability and effectiveness of combination support of the extraaortic balloon (EAB) and the ventricular assist cup (VAC) to the acute heart failure model. Under general anesthesia, 10 adult dogs were used. Through the median sternotomy, EAB was placed around the ascending aorta and VAC in the pericardial cavity. After heart failure was induced by administration of propranolol, the on-off tests of devices were done as follows. Only EAB was used, and only VAC was used and both devices were used. Regional blood flows (RBFs) of both ventricles, liver kidneys, and brain were measured by colored microsphere technique. Hemodynamic parameters were also measured. In heart failure model, cardiac output (CO) decreased to 66% of control value. In the group assisted by EAB, aortic peak-diastolic pressure and RBFs of both ventricle and brain increased significantly. In the group assisted by VAC, CO and RBFs of all but the left ventricle significantly increased. In the group assisted by EAB and VAC, aortic peak-diastolic pressure, CO, and all five RBFs significantly increased. These results suggest the combination of EAB and VAC is applicable and effective and would be a promising implantable device for the chronic heart failure.

[Effects of intermittent wakening on sleep pattern of nighttime caregiver: an EEG study with a single subject]

In order to investigate the effects of night wakening on sleep pattern of caregiver, a woman aged 45 years was studied using electroencephalogram (EEG). After two adaptation nights, her all-night EEG readings were recorded for six nights. During the first three consecutive nights, the subject slept by the side of a patient at a private ward of hospital and wakened by herself several times a night to provide care for the patient (care nights). Of the later three nights, her sleep EEGs were recorded at her home (free nights). The first free night was following three care nights and the other two free nights were after 2 weeks. The results were summarized as follows; 1) Sleep period time (SPT) of care nights differed in different nights. In contrast to the SPT range of 356-367 min during free nights, it was 271-391 min during the care nights. 2) The rhythm of sleep cycles of care nights was not stable, though the subject wakened by herself, not using an alarm clock. 3) Although there were few changes occurring in sleep efficiency (SE) and percent each stage for SPT (%SPT) between the first and second care night, SE of the third care night was more similar to SE of free nights than SE of the first two care nights, and so was %SPT of the third care night. 4) Sleep latency (SL) decreased during the four consecutive nights, i.e. the three care nights and the first free night, and SL of the third care night and the first free night were shorter than SL of the last two free nights. The accumulation of fatigue and stress of nighttime care was suggested.

[A study of nursing systems in transition in developed countries]

The present study was designed to investigate nursing systems in other countries in comparison with the current system in Japan, and thereby assess how nursing personnel should be in order to improve the quality of nursing. The study focused on the actual situation of the nursing system and licensed practical nurses (LPNs) or second-level nurses similar to LPNs in other countries. The survey was conducted in regard to six countries considered to be advanced in the development of nursing activities and likely to provide useful suggestions for the future direction of nursing in Japan: Australia, Canada, France, Sweden, the United Kingdom and the United States. Questionnaires were sent to the heads or staff of a total of 29 organizations, including WHO Collaborating Centers and professional organizations for nursing, in these countries. Nineteen organizations responded (response rate: 65.5%), and an effective response with completed questionnaire forms was obtained from 15 organizations. In addition, an interview survey was conducted on three nursing administration and education experts in the United States in order to acquire clear understanding of the actual state of nursing in health care practice. The results were as follows: 1. Six countries (Japan included) excluding France had LPNs. Educational preparation for LPNs has been discontinued in the United Kingdom. 2. The number of nurses per 1,000 population was lowest in Japan: the total number of registered nurses (RNs) and LPNs in Japan was less than the number of RNs in the United Kingdom. Only in Japan the proportions of LPNs and RNs were similar, while in other countries of number of LPNs was one-third to one-fourth of the number of RNs. 3. In the five other countries having LPNs, the nurse's competency or scope of practice was clearly defined for both LPNs and RNs. In contrast, no clear line was drawn between the two in Japan. 4. The length of education required for LPNs ranged from 11 to 14 years (including the period of compulsory education) and was shortest in Japan (11 years). The educational requirement for admission to LPN school in Japan was 9 years of compulsory education (graduation from junior high school), whereas in other countries it was at the level of senior high school graduation. 5. Four countries had conversion programs for LPNs to become RNs, and the conversion courses were positioned within the framework of higher education comparable to the university level. 6. In the United Kingdom, where the educational preparation for LPNs has been discontinued, nurses are included in a single higher level profession. At the same time there was found to be a need to train and educate auxiliary personnel in order to maintain multi-level care services. Because of the increasing tendency toward advanced medical technology and highly specialized medical care associated with the rapidly increasing care needs in the community, the current educational preparation for LPNs in Japan in unsatisfactory as a training and educational system for nursing manpower to cope with the current situation. The above findings suggest that the education system for LPNs be reviewed with a view to discontinuing it and consolidating nursing education in Japan.

Expression of neuronal nitric oxide synthase in spinal motoneurons in aged rats

We investigated the expression of nitric oxide synthase (NOS) in motoneurons of aged rats by the nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase (NADPH-d) reaction. The number of NADPH-d positive neurons (i.e. presumed motoneurons) in the motor nucleus at L4-L6 level of the spinal cord was 0.0 +/- 0.0 for 13- to 15-month-old rats, 2.2 +/- 0.8 for 24-month-old rats, and 7.9 +/- 5.4 for 29- to 32-month-old rats. These NADPH-d positive neurons were multipolar in shape and the soma cross-sectional area was 820 +/- 245 mu2 (n = 56; range, 359-1460 mu2) which was similar to the value for alpha-motoneurons. The results indicate that nitric oxide (NO) may be produced by a few motoneurons in the aged rat spinal cord and may lead these neurons to eventual death.

Changes in serum concentrations of calcium and its regulating hormones during tail suspension in rats

To study the effects of mechanical unloading on systemic calcium homeostasis, we determined the changes in serum concentration of calcium, 1,25-dihydroxyvitamin D3 and parathyroid hormone (PTH) during tail-suspension experiments in rats. The serum concentration of ionized calcium significantly increased during the 14 days of the suspension, reflecting increased bone resorption in the hind limbs. This hypercalcemic condition should cause suppression in PTH secretion. Indeed, serum PTH levels decreased on Day 3 of the suspension. This decrease was associated with lower serum levels of 1,25-dihydroxyvitamin [correction of dihyroxyvitamin] D3 probably due to a decrease in the activity of 1 alpha-hydroxylase in the kidneys resulting from a decrease in PTH secretion. Since it is known that 1,25-dihydroxyvitamin D3 stimulates osteoblastic function, it is suggested that endocrine responses evoked by tail suspension aggravate disuse atrophy of the hind limbs.

Effects of bisphosphonate on bone metabolism in tail-suspended rats

Our previous studies demonstrated that tail suspension causes early, transient increases in osteoclastic activity, followed by a decrease in osteoblastic activity in the hind limbs of rats. To assess whether this early increase in bone resorption is important in the development of disuse atrophy, the effect of YH529, a third generation bisphosphonate, was studied on hind limb atrophy in rats subjected to tail suspension. YH529 (YH group) or PBS (control group) were administered subcutaneously in 5-week-old male Wistar rats suspended for 7 days. In the control group, wet weight, calcium and phosphorus contents decreased significantly in the femur but they did not change in the humerus. In the YH group, however, these parameters did not change significantly in the femur, but both calcium and phosphorus increased significantly in the humerus. These results indicate that the inhibition of bone resorption by YH529 prevents the development of disuse atrophy induced by tail suspension. It is thus suggested that early increases in bone resorption are important for the development of disuse bone atrophy.

Human melanoma treated by boron neutron capture therapy: comparison of the clinical response with the predicted response

PURPOSE

A patient with malignant melanoma on the left foot was treated by thermal neutron capture therapy using 10B-paraboronophenylalanine. We compared the actual (clinical) response with the predicted response estimated using our past experimental and clinical data, and discussed some problems to be overcome in the future.

MATERIALS AND METHODS

We adopted an intravenous drip infusion of the compound whereby 170 mg/kg of the drug was administered over 4-5 hours before neutron irradiation. The patient was then irradiated with thermal neutrons from the Musashi Reactor at a reactor power of 100 kW and a neutron flux of 1.0 x 10(9) n/cm2/s at the collimator surface. The total absorbed dose to the melanoma and the surrounding skin was calculated by multiplying the thermal neutron fluences by the conversion factor.

RESULTS

The total absorbed doses to the melanoma and the surrounding normal skin were calculated as 19.0 and 9.4 Gy, respectively. These absorbed doses were estimated at 33.5 and 14.2 RBE-Gy, respectively, assuming that the relative biological effectiveness (RBE) of the high LET radiations was 2.0 and that each component of the mixed radiation was simply additive. The melanoma showed marked regression with mild skin reaction (dry desquamation) a month after therapy, and finally disappeared 10 months after therapy. There were no no substantial side effects.

CONCLUSION

We concluded that the outcome of our calculated dose values agreed well with the clinical response and that their compatibility indicated considerable validity for our approach. However, there are still some problems-uncertainty concerning the 10B concentration in tumor and skin, determination of the total absorbed dose, and a single curative dose for malignant melanoma-to be overcome with regard to clinical use of this therapy.

A compressive type skeletal muscle pump as a biomechanical energy source

The purpose of this study was to assess the applicability of the conditioned latissimus dorsi muscle as an energy source for circulatory assist devices. The authors developed a pneumatic chamber as a muscle actuator. The pneumatic chamber placed between latissimus dorsi muscle and chest wall was compressed by the burst stimulated muscle and, thereby, converted muscle contractile power into pneumatic pressure. The authors report the performance of the implanted pneumatic chamber at a chronic phase, and the capability of the conditioned muscle in situ as an energy source for circulatory assist devices. Six adult mongrel dogs were used. At the first operation, a pacemaker for muscle conditioning and the pneumatic chamber were implanted. After 12 weeks of muscle conditioning, the performance of the pneumatic chamber with conditioned muscle was evaluated. The pressure generating capability of a chamber buried in fibrous adhesions was reduced to approximately 65% of that of a chamber without adhesions. The stroke volume and stroke work of the assist device driven by the developed pneumatic pressure were measured. The maximum stroke work of the circulatory assist was greater than the stroke work of the right ventricle, but less than that of the left ventricle. In respect to stroke volume, the pneumatic chamber could drive the circulatory assist device against not only a pulmonary range of afterload, but also a systemic range of afterload, when high pre load was available. These results indicate that the compressive skeletal muscle pump with conditioned latissimus dorsi muscle generates acceptable hemodynamic work for right ventricular bypass or aortic counterpulsation. In the long-term, the interface between tissue and actuator is the major obstacle to developing a muscle powered assist device.

Purification and properties of tyrosinase isozymes from the gill of Lentinus edodes fruiting body

Six tyrosinase isozymes were purified from the browned gill of the fruiting body of Lentinus edodes by ammonium sulfate fractionation, DEAE-Sephacel and Q-Sepharose column chromatography, and partially denaturing SDS-PAGE. At the step of Q-Sepharose column chromatography, two active fractions (A and B) were obtained. Each fraction was separated to three further fractions, A1, A2, and A3, and B1, B2, and B3, respectively, by partially denaturing SDS-PAGE. All these isozymes consisted of two types of polypeptides: alpha polypeptide (A alpha or B alpha) and either beta (A beta or B beta) or gamma polypeptide (A gamma or B gamma). The alpha polypeptide contained the consensus amino acid sequence of the active site of known tyrosinases, which is considered to act as a catalytic subunit. From the results of peptide mapping and the amino acid composition, A alpha and B alpha polypeptides were considered to be different proteins. The kinetic properties of the purified tyrosinase isozymes differed greatly according to whether they contained beta or gamma polypeptide, indicating these polypeptides to be a possible regulatory subunit.

Overloading a muscle does not alter the rate of motoneuronal loss in aged rats

Effects of increased activity on neuronal cell death was investigated in the motor nuclei innervating normal and overloaded medial gastrocnemius (MG) muscles of Fischer 344 rats. The MG muscle was overloaded by the unilateral surgical ablation of synergists at the age of 17 months (group A) or 24 months (group B). When the rats reached the age of 24 and 28 months (group A) or 30 months (group B), motoneurons innervating the MG muscle were labeled bilaterally with horseradish peroxidase injected into the MG nerve. The wet weight of the muscle on the operated side was consistently heavier than that of the contralateral, intact side. The number of labeled neurons decreased with advancing age, and there was no difference in the magnitude of decline found between motor nuclei innervating intact and hypertrophied muscles. Thus, overloading the MG muscle did not retard or accelerate the age-related loss of motoneurons innervating this muscle. These findings indicate that the causal relationship between motoneuronal activity and death with advancing age needs to be studied further.

Constitutive STAT1 tyrosine phosphorylation in U937 monocytes overexpressing the TYK2 protein tyrosine kinase does not induce gene transcription

Janus kinase (JAK) family protein tyrosine kinases are constituents of a signaling path leading to tyrosine phosphorylation and activation of signal transducer and activator of transcription (STAT) family transcription factors. IFN-alpha activates two JAK family protein tyrosine kinases (TYK2 and JAK1) and two STAT family proteins (STAT1 and STAT2). We have generated a line of U937 promonocytes expressing a tyk2 transgene. 12-O-Tetradecanoylphorbol-13-acetate-mediated differentiation into monocytes resulted in transgene induction and both overexpression and constitutive activation of the kinase. TYK2 protein in the transgenic line was found predominantly in a membrane fraction. Coprecipitation experiments demonstrated an association of constitutively tyrosine-phosphorylated TYK2 with the IFN-alpha receptor 1 chain. TYK2 activity led to an IFN-alpha-independent appearance of tyrosine-phosphorylated STAT1 but not STAT2 or JAK1 proteins. Consistent with this, TYK2 activity also caused constitutive activation of the IFN-alpha-responsive transcription factor IFN-alpha activation factor, a dimer of tyrosine-phosphorylated STAT1, but not of the IFN-alpha-responsive transcription factor IFN-stimulated gene factor 3, a heterotrimer of tyrosine-phosphorylated STAT1 and STAT2 in association with a M(r) 48,000 DNA-binding subunit. Expression of STAT1 target genes was not observed in TYK2-overexpressing cells. Our results suggest that in addition to activated TYK2, there is a requirement for additional, IFN-alpha-dependent signals for the phosphorylation of STAT2 and the generation of IFN-stimulated gene factor 3 as well as for the conversion of tyrosine-phosphorylated STAT1 into transcriptionally active IFN-alpha activation factor.

Experimental study of extraaortic balloon counterpulsation as a bridge to other mechanical assists

A special extraaortic balloon was developed that can be placed around the ascending aorta. This balloon can easily support the heart temporarily in a median sternotomy field, especially in cases in which it is difficult to use intraaortic balloon pumping because of peripheral arterial disease. The goal of this study was to judge the applicability of this extraaortic balloon counterpulsation. An extraaortic balloon was placed around the ascending aorta of eight adult canines. Two heart failure models were used in this study: group A-moderate heart failure; group B-severe heart failure. In group A, the aortic systolic pressure was significantly reduced (9.3%, p < 0.01), but in group B, there was no significant change. In group A, there was a significant increase in cardiac output (12.0%, p < 0.01), but in group B, there was no significant change. The endocardial viability ratio in both groups significantly increased (group A: 11.3%, p < 0.01; group B: 11.9%, p < 0.05). An extraaortic balloon around the ascending aorta is easily applicable through a median sternotomy, and can be used as a bridge to more powerful mechanical assists when intraaortic balloon pumping cannot be used.

Developmental alterations in NMDA receptor-mediated currents in neonatal rat spinal motoneurons

Postnatal development of N-methyl-D-aspartate (NMDA) receptors expressed in motoneurons was studied by tight-seal whole-cell recordings from identified motoneurons in slices of neonatal rat spinal cord. The magnitude of NMDA-induced currents was large during the early postnatal period, and then it decreased gradually through postnatal day (PND) 15. The pharmacological properties of NMDA-induced currents altered during this period, suggesting that the combination of NMDA receptor subunits changes during development. The magnitude of the NMDA receptor-mediated component of excitatory postsynaptic current evoked by electrical stimulation of an adjacent neuron also decreased from PNDs 1-5 through PNDs 11-15. NMDA receptors appear to underlie the mechanisms of activity-dependent development of spinal motoneurons during early postnatal life.

A percutaneously accessible pulsatile left ventricular assist device: modified assist device type 5

To provide percutaneous access, a new circulatory assist system was developed. We call this newly developed system the modified assist device (MAD). The system is composed of a sac-type blood pump and cannula. Inflow and outflow valves are mounted in the apex and at the side wall 10 cm from the apex of the cannula, respectively. During systole, the blood is sucked from the left ventricle through the inflow valve of the cannula connected to the blood pump, and during diastole, the blood is ejected to the root of the aorta through the outflow valve. In vitro and in vivo evaluations of the pump performance were performed. The maximum flow rate of 1.9 L/min was obtained in the mock circulatory system. In our animal experiment, effective systolic unloading and diastolic augmentation were observed by activation of this system during regular sinus rhythm. In conclusion, the MAD-5 is thought to be percutaneously accessible and increases systemic and coronary flow.

Effects of the thermal conditions of the dressing room and bathroom on physiological responses during bathing

The effects of the thermal conditions of the dressing room and bathroom on the physiological responses during bathing were assessed. Six female students participated in this experiment. Three climate chambers were used as a living room, a dressing room and a bathroom. The living room was thermoneutral and maintained at 25 degrees C, while the thermal conditions of the dressing room and bathroom were as follows: (A) cold (10 degrees C), (B) cool (17.5 degrees C) thermoneutral (25 degrees C). The subjects wore standard clothing (0.65 clo). Heart rate (HR), blood pressure, rectal (Tre) and skin temperature, and subjective thermal sensation were recorded. 1) Marked increases in systolic blood pressure (SBP) after undressing and redressing in the dressing room and during washing were observed under the cold conditions. 2) A significant negative correlation was found between the dressing room temperature and increased SBP compared to before bathing (r = -0.684, p < 0.01, n = 18). 3) After exposure, mean skin temperature (Tsk) showed marked differences among the three conditions despite the rest taken under the same thermal conditions. 4) A significant negative correlation was found between Tsk and the increase in SBP of after undressing relative to that before bathing (r = -0.695 p < 0.01, n = 18). These findings suggested that 25 degrees C was the most appropriate temperature for the bathroom and dressing room, since the increase in blood pressure was minimum and subjective thermal sensation was neutral (neither cool nor warm) to warm under this thermal condition, and 17.5 degrees C at which the increase in blood pressure was within the physiological fluctuation range (+/- 10 mmHg) is the minimum tolerable temperature.

Dynamic and static sensitivities of muscle spindle primary endings in aged rats to ramp stretch

Responses of the presumed primary sensory endings of de-efferented muscle spindles to a ramp stretch were investigated in the medial gastrocnemius muscle of male Fischer 344 rats of two age groups (i.e. 10-14 and 28-30 months) anesthetized with urethane and chloralose. The static sensitivity was similar for both middle-aged and aged rats, although the discharge frequency was lower for aged rats when compared at the same muscle length. The value of the dynamic index was significantly lower in aged rats than in middle-aged rats, suggesting a decrease in the dynamic sensitivity of muscle spindle primary endings in aged rats.

Evolution of the response patterns to dietary carbohydrates and the developmental differentiation of gene expression of alpha-amylase in Drosophila

Intraspecific variation of alpha-amylase activity in D. melanogaster and D. immigrans, which is distantly related to D. melanogaster, and interspecific variation of alpha-amylase activity in 18 Drosophila species were examined. The amount of intraspecific variation of alpha-amylase activities measured in terms of coefficient of variation in D. melanogaster and D. immigrans was one-half and one-tenth or less, respectively, of the interspecific variation in 18 Drosophila species. We also surveyed the response patterns of alpha-amylase activity to dietary carbohydrates at the larval and adult stages. The levels of alpha-amylase activity depended on both repression by dietary glucose (glucose repression) and induction by dietary starch (starch induction). In general, our data suggest that glucose repression was conserved among species at both stages while starch induction was mainly observed in larvae, although the degree of the response depended on species. In D. lebanonensis lebanonensis and D. serrata, larvae expressed electrophoretically different alpha-amylase variants (isozymes) from those of adult flies. These results may suggest that the regulatory systems responsible both for the response to environment and developmental expression are different among species in Drosophila.

Effects of stress on Kv1.5 K+ channel gene expression in the left ventricle of rat hearts

Voltage-dependent K+ channels contribute to the repolarization phase of the cardiac action potential. An increase in Kv1.5 K+ channel gene expression by a pharmacological dose of glucocorticoid was reported recently in the heart of an adrenalectomized rat. In this study, we examined whether physiological elevations of glucocorticoid induced by tail suspension affects the K+ channel gene expression. Five-week-old male Wistar rats were subjected to tail suspension for three days. Total RNA was extracted from the ventricle, and the level of Kv1.5 mRNA was determined by Northern blot analysis. On the first day, the Kv1.5 mRNA had increased over the non-suspended rat. By the third day, mRNA had increased significantly by more than 3-fold. knowing that urinary excretions of glucocorticoid increase in tail-suspended rats, these findings suggest that physiologically elevated glucocorticoid may upregulate Kv1.5 K+ gene expression.

Catecholamine response to stress: age related modifications in tail-suspended rats

The catecholamine response to acute stress has been shown to change with age. However, alterations under chronic stress conditions have not been established. This study attempted to determine whether aging modifies the catecholamine response to chronic stress load in rats subjected to tail suspension. Urinary excretions of epinephrine (E) and norepinephrine (NE) were monitored before and during the tail suspension experiments in rats at two different ages: 5 weeks old (young) and 18 months old (aged). Basal excretions of E and NE before the suspension were higher in the aged rats, indicating that sympathetic-adrenal medullary activities increase with age under resting conditions. The chronic stress load elicited E responses in the aged rats similar to those in the young rats. The NE responses, however, were completely different in that tail suspension caused a greater increase in NE excretion in the young rats than in the aged rats. This finding suggests that the sympathetic response to chronic stress load changes with age.

Changes in the markers of bone metabolism following skeletal unloading

To elucidate the mechanism in disuse bone atrophy induced by skeletal unloading, we studied the indices of bone resorption and bone formation in the femur of tail-suspended rats. The duration of the suspension ranged from 1 to 14 days. Tartrate-resistant acid phosphatase mRNA, an index used to evaluate bone resorption, increased significantly more than the controls for the first 3 days of the tail-suspension experiments, compared those in controls. Osteocalcin and alkaline phosphatase, two common markers for bone formation, were also monitored. Osteocalcin mRNA started to decrease after 3 days of suspension. Five days later, alkaline phosphatase mRNA showed a decrease. Levels of both of these mRNAs remained low for the remaining suspension period. Sequential changes in the markers for bone metabolism indicate that the transient increase in bone resorption preceded the decrease in bone formation in the development of disuse bone atrophy induced by skeletal unloading.

Applicability of the latissimus dorsi muscle in situ as a biomechanical energy source

The purpose of this study was to assess the applicability of the latissimus dorsi muscle in situ as an energy source for a circulatory assist device. A pneumatic chamber, devised by the authors, was inserted beneath the muscle and compressed by contractions of the muscle so that muscle contractile power was converted into pneumatic pressure. The optimal insertion position of the chamber beneath the latissimus dorsi muscle, and the influence of chamber size on generated pneumatic pressure, were investigated. The pneumatic chamber functioned better when it was placed in a proximal position (third intercostal space) than in a middle or distal position. Using a mock circuit, the performance of the pneumatic chamber as an energy source for a circulatory assist device was evaluated. The pneumatic chamber was able to generate power sufficient to drive a right ventricular assist device as far as stroke work was involved. When the pneumatic chamber was operated with a high afterload, it could even be an energy source for aortic counterpulsation.

Thermal conditions in the bathroom in winter and summer, and physiological responses of the elderly during bathing

Thermal conditions in the bathroom and physiological responses were examined during winter and summer. The subjects were 22 male and 20 female elderly people, between 65 and 88 years old living in 25 houses in Gunma Prefecture, Japan. Heart rate, blood pressure, skin temperature and thermal sensation were measured during bathing. Changes in thermal sensation due to bathing were assessed in the living room and dressing room on a 9-point scale. Then they were asked about the purposes of bathing and the facilities of bathroom and dressing room. The results are summarized as follows: 1. The purpose of bathing in winter was to warm up for more than 80% of the subjects. In summer, all subjects felt refreshed by bathing. Eighty-five percent of the subjects took a bath every other day in both seasons. 2. Fifty-two percent of the bathrooms had no ventilating fans and 32% had no exclusive dressing rooms. 3. The average room temperature in the dressing rooms was 13-14 degrees C in winter. Thermal sensation was 'cool', 'slightly cold' or 'cold' for more than two-thirds of the subjects when they were partially nude, and there were no heaters in most dressing rooms. 4. The heart rate increased steadily, and reached a maximum value in a partially dressed condition in both seasons. 5. In winter, a marked increase of systolic blood pressure was observed in the partially nude condition. There was a significant difference between the before bathing condition and partially nude condition in winter.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential effects of aging on motoneurons and peripheral nerves innervating the hindlimb and forelimb muscles of rats

We examined the number and size of ulnar (forelimb) and medial gastrocnemius (MG, hindlimb) motoneurons in middle-aged (9 months of age) and aged (27 months of age) male Fischer 344 rats. Morphological properties of the ulnar and the MG nerves were also studied. No significant difference was found in the mean number of the ulnar motoneurons between the two age groups, while that of MG motoneurons was significantly less in aged animals. A decrease in the number of myelinated fibers (including both afferent and efferent fibers) in the ulnar nerves was less than that in the MG nerves, although the age difference was not significant in either of the nerves. Soma atrophy of aged motoneurons was found in both MG and ulnar motor nuclei. The mean fascicular areas and myelinated fiber diameters were significantly increased in both the MG and the ulnar nerves in aged rats, but these were less pronounced for the ulnar nerve. The results indicate that most ulnar motoneurons, unlike MG motoneurons, survive at least to the age of 27 months. Morphological changes in the peripheral nerves were also less for the ulnar nerve than for the MG nerve. Thus, we conclude that the effects of aging on motoneurons and peripheral nerves innervating MG muscle of the hindlimb are greater than those innervating forelimb muscles.

Fos induction in the medullary dorsal horn and C1 segment of the spinal cord by acute inflammation in aged rats

In order to elucidate the effect of aging on nociceptive neurons in the central nervous system, c-fos was used as a marker of excitability of neurons in the medullary dorsal horn (MDH) and the first spinal segment (C1) following noxious stimulation of the lateral face of young and aged rats. The distribution of c-fos-positive cells was dense in the superficial laminae and sparse in the deep laminae of the MDH and C1 in both young and aged animals following subcutaneous injection of formalin into the lateral face, whereas few c-fos-positive cells were labeled after saline injection. The distribution of c-fos-positive cells in the superficial laminae of the aged rats was found to be denser and more rostro-caudally expanded compared to that in the young rats. C-fos-positive cells were distributed more rostro-caudally in aged than in young rats. There was no difference between young and aged rats in the distribution of c-fos-positive cells in the deep laminae. Substance P (SP), 5-HT and calcitonin gene-related peptide-like immunoreactive (CGRP-LI) fibers and varicosities showed similar distribution density in the MDH and C1. Furthermore, many 5-HT-LI aberrant fibers and varicosities were observed in the MDH and C1 of the aged rats. The SP-LI and CGRP-LI cells in the trigeminal ganglion of aged rats were larger than those of young rats. These findings suggest that a deficit of the descending 5-HT inhibitory system produces the increment of c-fos-positive cells in the MDH and C1 of aged rats, resulting in the recruitment of a larger number of neurons in the superficial laminae of the MDH and C1 for conveying nociceptive sensory information to the central nervous system.

Body movements of the elderly during sleep and thermal conditions in bedrooms in summer

The frequency of body movement in the elderly and young people during sleep was measured in order to investigate the effect of hot thermal environments on sleep in summer. Simultaneously, room temperature and humidity were also measured. In the morning after measuring body movements, the subjects completed a questionnaire about their night's sleep. The results obtained were as follows: 1) The time of going to bed and rising in the elderly was significantly earlier than the young. 2) The elderly had a tendency to judge their sleep as "good", however, there were no significant differences between the two groups. 3) The room temperature for the elderly during sleep ranged from 25 to 28 degrees C (mean 26.5 degrees C). On the other hand, it was between 20 and 30 degrees C (mean 27.1 degrees C) in the young, which was significantly higher than that of the elderly. 4) Body movement in the elderly during sleep was significantly greater than those in the young. 5) A significant relation between body movement and room temperature was found within each group. Under conditions of less than 28 degrees C of room temperature, there were significantly higher rates of body movement in the elderly.

[Experimental study on organ perfusion by intraaortic balloon counterpulsation with double balloon catheter]

Newly-developed catheter for the intraaortic balloon counterpulsation with cardio-renal assist was examined on animal model. The catheter consists of two balloon segments between which the celiac trunk, the superior mesenteric artery and the renal artery are to be placed. Statistical comparison on each hemodynamic element was carried out between the catheter (DBC), conventional single balloon catheter (SBC) of the same balloon volume as DBC and no assist (None) groups. There were no significant changes between SBC and DBC in cardiac output, femoral arterial flow and central venous pressure. Renal arterial flow and urinary output were significantly increased in DBC (None 14.4 +/- 3.9, SBC 22.6 +/- 5.6, DBC 31.0 +/- 6.9 ml/min in renal arterial flow, None 33 +/- 9, SBC 64 +/- 14, DBC 78 +/- 20 ml/h in urinary output, p < or = 0.05). After the remodeling adjust to the human stature, a clinical application would be considered.

Clinical use of low porosity woven ultrafine polyester fiber grafts

A woven fabric graft made of ultrafine polyester fibers (UFPF) (Toray Graft, water porosity: 100 ml/min/cm2:120 mm Hg H2O) was clinically applied in 81 cases (28 thoracic aortic aneurysms, 6 thoracoabdominal aortic aneurysms, 42 abdominal aortic aneurysms, and 5 atherosclerotic obstructions of the peripheral arteries). Eight patients died after surgery due to causes unrelated to the graft. The other 73 patients were in good condition after surgery. For operations requiring extracorporeal circulation, the graft was presealed with human albumin. For the abdominal aortic aneurysms, the graft was preclotted in situ with nonheparinized autoblood after the completion of the proximal anastomosis. It took about 2 min to complete the preclotting. A nonsealed graft was used for the reconstruction of peripheral arteries for the intraaortic balloon pumping procedure. The graft was easy to handle. There was no cut edge fraying problem with the graft in any direction of cutting. Even after presealing, the graft was soft and pliable enough to enable easy adaptation and anastomosis. Just after implantation, bleeding was minimal from the graft wall, anastomotic sites, and suture pores, and it stopped spontaneously. These clinical data showed that the woven UFPF graft exhibited both easy handling despite in spite of low porosity and safe application in the reconstruction of arterial systems even under totally heparinized conditions during extracorporeal circulation.

Glucocorticoids potentiate the action of atrial natriuretic polypeptide in adrenalectomized rats

Adrenal insufficiency in human and rat is associated with an impairment of the diuretic response to water load, and only glucorticoids (GCs) restore this deficit. Our observation that GCs potentiate atrial natriuretic polypeptide (ANP)-stimulated cGMP production in cultured renal cells prompted us to examine the possibility that GCs may restore the diuretic response through the potentiation of ANP action. Initially, changes in urine volume and ANP levels were studied in adrenalectomized (Adx) and sham-operated intact rats after an oral water load of 5 ml/100 g BW. Urine volume after water load was 4.5 +/- 0.5 ml/30 min in the intact rats, whereas it was 0.8 +/- 0.2 ml/30 min in the Adx rats. In the intact rats, a significant increase in plasma ANP level was observed 30 min after the water load, whereas no increase was observed in Adx rats. This defective ANP response may be involved in the impairment of the diuretic response in Adx rats. Indeed, pretreatment of Adx rats with dexamethasone (Dex, 20 micrograms/100 g BW) increased plasma ANP levels even before water load and improved diuretic response. Subsequently, effect of iv administration of human or rat ANP at a pharmacological dose (2.5 micrograms/100 g BW) on urine volume, osmolarity, and urinary excretion of cGMP, and sodium was studied in Adx rats that received an oral water load 30 min before ANP. Dex treatment was achieved by per os administration 3 h before the ANP injection. In Adx rats, the urine volume after ANP administration was 1.2 +/- 0.1 ml/30 min, and pretreatment with Dex markedly increased the urine volume to 6.3 +/- 0.4 ml/30 min. Dex also increased ANP-induced osmolar and sodium excretion by 2.6- and 2.9-fold, respectively. Although urinary excretion of cGMP was increased in Adx rats by ANP administration, a further significant increase was observed by the pretreatment with Dex. Injection of (Bu)2cGMP to Adx rats pretreated with Dex resulted in a significant increase in urine volume and osmolar and sodium excretion. However, no significant increase in urine volume was observed in Adx rats not pretreated with Dex. The present study suggests that GCs restore the diuretic response to acute water load not only by increasing the secretion of ANP but also by potentiating ANP-stimulated cGMP production. Furthermore, GCs may augment ANP action at one or more steps other than cGMP formation because administration of (Bu)2cGMP to Adx rats did not correct the diuretic response to water load.

In vitro reconstruction of hybrid arterial media with molecular and cellular orientations

A hybrid medial tissue composed of a type I collagen gel, into which smooth muscle cells (SMCs) derived from bovine aortic media were 3-dimensionally (3D) embedded, was constructed around an elastomeric silicone tube (outer diameter: 8 mm). Subsequently, hybrid tissues thus prepared were subjected to three modes of mechanical stimulation in the medium: one was subjected to flotation with no disturbance (isotonic control), the second was kept isometrically (static stress) and the third was subjected to continuous periodic stretch by inflation of the embedded silicone tube which stimulated arterial pulsation (dynamic stress, amplitude: 5% in inner diameter; frequency: 60 RPM). After a 5-day culture period, hybrid tissues were morphologically investigated. In control gels, polygonal SMCs and extracellular collagen fiber bundles were randomly oriented. On the other hand, upon static or dynamic stress loading, bipolar spindle-shaped SMCs and dense collagen fiber bundles were aligned circumferentially around the silicone tube, which proceeded with time. The orientations of SMCs and collagen fibers were more prominent in dynamically stressed hybrid tissues than those in statistically stressed ones. The pulsatile stress-loaded hybrid medial tissue mimicked the media of native muscular arteries in terms of cellular and molecular orientations.

A targeting model of boron neutron-capture therapy to hepatoma cells in vivo with a boronated anti-(alpha-fetoprotein) monoclonal antibody

We described previously that 10B atoms delivered by monoclonal antibody (mAb) exerted a cytotoxic effect on AH66 cells in a dose-dependent manner upon thermal neutron irradiation in vitro. In the present study, the delivering capacity of boronated anti-(alpha-fetoprotein) (AFP) mAb to carry 10B atoms to AFP-producing tumor xenografts in nude mice was determined. Boronated mAb was prepared by conjugating 50 mM 10B compound to an anti-AFP mAb (2 mg/ml) using N-succinimidyl-3-) (2-pyridyldithio) propionate. The number of 10B atoms conjugated directly to the mAb was estimated to be 459/antibody by prompt gamma-ray spectrometry. Boron concentrations in tumor tissue obtained 12, 24, 72, and 120 h after injection of 3.0 mg 10B-conjugated anti-AFP mAb were 11.10 +/- 3.12 (SD, n = 6). 29.30 +/- 5.11, 33.02 +/- 11.8, and 12.91 +/- 5.62 ppm respectively. For control 10B-conjugated anti-dinitrophenol (DNP) mAb, the values were 9.59 +/- 0.99, 10.37 +/- 2.86, 10.00 +/- 2.95, and 8.83 +/- 4.71 ppm respectively. The concentrations in blood were less than 0.40 +/- 0.10 ppm with anti-AFP mAb and less than 0.51 +/- 0.15 ppm with anti-DNP mAb at each sampling time (12, 24, 72, and 120 h). The number of 10B atoms delivered to the tumor cells was calculated to be 0.62 x 10(9), 1.63 x 10(9), 1.84 x 10(9) and 0.72 x 10(9) at each sampling time after injection of 10B-anti-AFP mAb. The amount of 10B atoms necessary for effective boron neutron-capture therapy was estimated to be 10(9)/tumor cell. We were able to carry 1.84 x 10(9) 10B atoms to AH66 tumor cells by using 10B-anti-AFP mAb. The accumulation reached its peak 72 h after injection. These data indicated that the 10B-conjugated antitumor mAb could deliver a sufficient amount of 10B atoms to the tumor cells to induce cytotoxic effects 72 h after injection upon thermal neutron irradiation.

Mechanical stress-induced orientation and ultrastructural change of smooth muscle cells cultured in three-dimensional collagen lattices

The effect of tensile stress on the orientation and phenotype of arterial smooth muscle cells (SMCs) cultured in three-dimensional (3D) type I collagen gels was morphologically investigated. Ring-shaped hybrid tissues were prepared by thermal gelation of a cold mixed solution of type I collagen and SMCs derived from bovine aorta. The tissues were subjected to three different modes of tensile stress. They were floated (isotonic control), stretched isometrically (static stress) and periodically stretched and recoiled by 5% above and below the resting tissue length at 60 RPM frequency (dynamic stress). After incubation for up to four wk, the tissues were investigated under a light microscope (LM) and a transmission electron microscope (TEM). Hematoxylin and eosin-stained LM samples revealed that, irrespective of static or dynamic stress loading, SMCs in stress-loaded tissues exhibited elongated bipolar spindle shape and were regularly oriented parallel to the direction of the strain, whereas those in isotonic control tissues were polygonal or spherical and had no preferential orientation. In Azan-stained samples, collagen fiber bundles in isotonic control tissues were somewhat retracted around the polygonal SMCs to form a random network. On the other hand, those in statically and dynamically stressed tissues were accumulated and prominently oriented parallel to the stretch direction. Ultrastructural investigation using a TEM showed that SMCs in control and statically stressed tissues were almost totally filled with synthetic organelles such as rough endoplasmic reticulums, free ribosomes, Golgi complexes and mitochondria, indicating that the cells remained in the synthetic phenotype. On the other hand, SMCs in dynamically stressed tissues had increased fractions of contractile apparatus, such as myofilaments, dense bodies and extracellular filamentous materials equivalent to basement membranes, that progressed with incubation time. These results indicate that periodic stretch, in concert with 3-D extracellular collagen matrices, play a significant role in the phenotypic modulation of SMCs from the synthetic to the contractile state, as well as cellular and biomolecular orientation.

Cytologic evaluation of phyllodes tumors as compared to fibroadenomas of the breast

In an attempt to better understand the cytopathologic features of phyllodes tumors (PTs) and to differentiate PTs from fibroadenomas (FAs) of the breast, cytologic smears prepared from 17 and 19 histologically diagnosed cases of PT and FA, respectively, were reviewed. PT cases were histopathologically graded as benign, borderline and malignant. Cytologically, hypercellularity of stromal cells with recognizable cytoplasm was observed in 6 of 7 borderline and malignant PT cases, but none of the benign PT or FA cases revealed such hypercellular stroma. Between all PT and FA cases, no statistically significant differences could be obtained in the nuclear size of stromal cells, folding of epithelial cell sheets or number of foamy macrophages. The study revealed that the abundance of stromal cells with cytoplasm, not naked nuclei, was strongly suggestive of borderline and malignant PT, but the differentiation between benign PT and FA was difficult on the basis of the cytopathologic findings.

Recent advances in basic aging research on the nervous system in Japan

Recent studies on aging of the nervous system are reviewed with special reference to neuronal cell death, compensatory reaction, trophic factors, brain cholinergic systems and the autonomic nervous system. Studies on spinal motoneurons labeled with a tracer substance transported retrogradely demonstrated differential age effect on different types. Compensatory reactions were also seen among surviving motoneurons. Motoneuronal survival appears to be correlated with the amount of activity. However, the causal relationship between them is not yet conclusive. The effects of nerve growth factor on sympathetic and dorsal-root ganglion cells seem to be well preserved in the aged, although there are some controversial findings on the ratio of NGF-dependent neurons versus NGF-independent neurons. It has been shown that acidic fibroblast growth factor or other substances may prevent degeneration of the basal forebrain cholinergic neurons and improve memory and learning performance in aged animals. The cholinergic system also regulates the regional cerebral blood flow, and this function seems to be well maintained in aged rats. Microneurography techniques have revealed increased activity of postganglionic sympathetic nerves innervating muscles in aged human subjects. The activity of preganglionic sympathetic nerves innervating the adrenal gland and the section rate of noradrenaline have been shown to increase in the aged rat. These changes might cause high blood pressure in the aged, although some species differences have been noted between humans and rats.

Developmental alterations in NMDA receptor-mediated [Ca2+]i elevation in substantia gelatinosa neurons of neonatal rat spinal cord

Using spinal cord slices prepared from neonatal rats, the intracellular free Ca2+ concentration ([Ca2+]i) in neurons located in the dorsal horn substantia gelatinosa (SG) was measured with microscopic fluorometry by loading fura 2-AM into neurons. Developmental alterations in the elevation of [Ca2+]i elicited by the glutamate analogs, NMDA and AMPA, were investigated from postnatal day (PNDs) 1 to 17. During the 1st week of postnatal life, when neuronal maturation of the SG is known to take place, the NMDA response remained large or even slightly increased. It subsequently showed a gradual decline. This pattern of postnatal changes is consistent with previously reported autoradiographic studies on NMDA-binding sites. The affinity of receptors for NMDA was found to decrease constantly during the period examined. The AMPA response and resting [Ca2+]i showed no significant developmental changes. Neonatal treatment with capsaicin, which has been shown to degenerate fine primary afferent fibers terminating in the SG, delayed the developmental decline in the NMDA-induced [Ca2+]i response. It is suggested that the number and the molecular properties of NMDA receptors expressed in the SG change during early postnatal neuronal maturation. The temporal coincidence between postnatal alteration in NMDA-induced [Ca2+]i elevation and neuronal maturation of the SG may indicate that intracellular Ca2+ regulated by NMDA receptor activation is related to postnatal neuronal maturation. Activation of fine primary afferent fibers may contribute to the observed developmental alterations in the NMDA response of SG neurons.

Development of a vascular prosthesis for a growing child. A graft expandable in vivo

Specially designed vascular prostheses that can be dilated after implantation using a percutaneous transluminal angioplasty (PTA) balloon catheter have been developed. The grafts are made of woven polyester fiber fabrics, the circumferential yarns of which consist of two different types of polyester fiber bundles: One is a straight weak bundle, the other is a strong bundle wound around the former. The graft with an initial diameter of 6 mm could be dilated to 9 mm by luminal inflation of the balloon four to five times at 10 atmospheres (atm) in vitro. After disrupting the weak bundle by the dilatation procedure, the strong bundles were straightened, which maintained the enlarged diameter of the new caliber. Grafts of 6 mm in initial diameter implanted into the thoracic aortas of mongrel dogs for 3 months also could be dilated in vivo by inflating the PTA four to five times at 15 atm, as found in the vitro study. Macroscopic observation revealed that, around the dilated grafts, only a tiny hematoma was formed and nominal subsequent bleeding was observed, which indicated that the dilatation procedure was performed safely. The graft, which enables adaptation of the hydrodynamic property of the graft to the increased blood flow by PTA after implantation, is applicable in a growing child.

Highly oriented, tubular hybrid vascular tissue for a low pressure circulatory system

A hierarchically structured hybrid vascular tissue was prepared from vascular cells and collagen. First a hybrid medial tissue was prepared by pouring a cold mixed solution of bovine aortic smooth muscle cells (SMCs) and Type I collagen into a tubular glass mold composed of a mandrel and a sheath (inner diameter, 1.5 mm; outer diameter, 7 mm; length, 7 cm). An SMC incorporating collagenous gel was formed with incubation at 37 degrees C. After the sheath of the mold was removed, the resulting fragile tissue cultured in the medium shrank in a time dependent manner to form an opaque, dense tissue. Seeding at a higher cell density and a lower concentration of collagen resulted in rapid and prominent shrinkage. Morphologic investigation showed that with time, bipolarly elongated SMCs and collagen fiber bundles became positioned around the mandrel. When the mandrel was removed, a tubular hybrid medial tissue was formed. A hybrid vascular tissue with a hierarchical structure was constructed by seeding endothelial cells onto the inner surface of the hybrid medial tissue. Prepared tissues tolerated luminal pressures as great as 100 mmHg and mechanical stress applied during the anastomotic procedure. This method allowed the authors to prepare hybrid medial tissues of predetermined size (specifically inner diameter, wall thickness, and length) and mechanical property, which all depend on the mold design, SMC seeding density, initial collagen concentration, and incubation period. Hybrid vascular tissues may provide physiologic functions such as antithrombogenicity and regulation of vasomotor tone when implanted into a venous system.

Boron neutron capture therapy of malignant melanoma using 10B-paraboronophenylalanine with special reference to evaluation of radiation dose and damage to the normal skin

A treatment regimen for boron neutron capture therapy of malignant melanomas is described using 10B-paraboronophenylalanine as the tumor-targeting compound. As a therapeutic dose, we adopted the maximum tolerable dose for the skin regardless of tumor 10B concentration. In practice, the maximum neutron fluence should be decided prior to starting irradiation. For this purpose, the kinetics of the concentration of 10B in the blood and skin and the skin-to-blood ratios were analyzed in the six patients who received 170 mg/kg of the compound intravenously, and skin concentrations during irradiation were predicted using a standard skin factor curve. This yields a skin concentration at time T based on the blood concentration at time 0. We calculated the maximum tolerable fluence yielding but not exceeding 18 RBE-Gy by assuming that the RBE of 14N(n,p)14C and 10B(n, alpha)7Li reaction for skin damage is 2.5. Actual skin reactions in three of five patients treated with the therapy were, as predicted, within tolerable limits, and we were able to obtain complete tumor regression in four cases. The results indicate that application of our logical approach will be useful for subsequent cases and further development of this therapy.

[Manometric study of the biliary sphincter zone: a comparison between the length of phasic activity and the narrow distal segment]

Motor activity of the sphincter of Oddi has been evaluated in 26 patients who underwent ERCP examination. Manometric recordings from the common bile duct and the sphincter of Oddi were performed with a single end-lumen perfused catheter. The number of successive 3 mm spaced black marks, observed during the pull-through from the first appearance of the proximal sphincter activity to that of duodenal pressure, was used to measure the length of the sphincter zone. In 14 of 26 patients, the length of phasic activity zone of the sphincter of Oddi was 9 mm. However, the narrow distal segment of the common bile duct was 15.1 +/- 3.6 mm in length. In same patients, the length of phasic activity zone was shorter than the anatomical one. The mean sphincter of Oddi pressure (SOP) at the distance of 6 mm from the papillary pore (77.8 +/- 22.1 mmHg) was greater than that of 9 mm (58.4 +/- 27.0 mmHg) and 12 mm (51.0 +/- 16.9 mmHg). These results suggest that the location of the orifice of catheter should be taken into consideration when comparing the SOP.

Behavior of arterial wall cells cultured on periodically stretched substrates

Cells in vital tissues align to form the most efficient configuration for functioning. Vascular cells of arterial walls are constantly exposed to fluid shear stress and pressure-induced periodic strain component, both of which are induced by pulsatile flow. In the present study, the effect of cyclic strain on the cellular orientation response and morphological changes of bovine arterial wall cells such as endothelial cells (ECs), smooth muscle cells (SMCs) and fibroblasts (FCs) was studied. Cells seeded onto transparent elastomeric films were subjected to periodic stretch-relaxation under various amplitudes ranging from 5 to 20% and at frequencies ranging from 15 to 120 RPM for up to 24 h. Time-lapse video-recorded images of stress-loaded cells were analyzed by a computer-aided morphometric system to quantitatively evaluate the cellular orientation responses and morphological changes. The stress-loaded cells tended to align perpendicularly to the direction of stretch with time, regardless of cellular species. More pronounced orientation was attained under operating conditions with higher amplitude and frequency of stretching. The response of SMCs and FCs advanced more rapidly than that of ECs. Meanwhile, little morphological change was observed, irrespective of stress-loading or nonloading. Understanding of mechanically induced orientation response provides a fundamental basis on tissue engineering and biomechanics.

[Factors effecting medication errors]

The purpose of this paper is to reveal factors that may occur or that may prevent medication errors, and to consider some measures of patients' safety. For this aim, we explored the characteristics of each ward and the characteristics of each nurse as well as their experiences about medication errors. The investigation was conducted at a approximately 650-bed university hospital located in a large urban center in Tokyo, and at a approximately 150-bed private hospital located in a suburb of Tokyo. Questionnaires were distributed in October 1991 and asked nurses to identify medication errors in which they had been personally committed within the past one-month. A response rate was approximately 70%. We were informed other information of each unit from head nurses--such as the unit size, case mix, nurse staffing and working schedule of nurses. Results indicate that on the questionnaires the nurses reported 10 times medication errors than they reported to head nurses. 56 percent of 155 nurses (except nurses who were working at an ICU and a mental ward) stated they had made medication errors or near misses during the 1-month reporting period. 30 percent of 155 stated they actually dealt with medication errors occurred by others. Several factors that effect medication errors have been identified by a stepwise discriminant analysis. The proportion of serious patient and the bed occupancy rate influenced the occurrence of medication errors. The educational career of a nurse, especially whether the nurse had been offered an assistant nursing program or not, related to dealing with and/or preventing medication errors.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of rabbit VX-2 subcutaneous tumor growth by gadolinium neutron capture therapy

VX-2 tumors growing in hind legs of New Zealand White rabbits (n = 4) were exposed to thermal neutrons for 40 min (2.1 x 10(12) neutrons cm-2) while one of two hind leg tumors of each rabbit was infused continuously with meglumine gadopentetate through a branch of the left femoral artery. The contralateral (uninfused) tumors served as controls. Although no differential distribution of gadolinium was achieved between the tumor and its adjacent normal tissue, the gadolinium concentration in the infused tumor was approximately 5-6 fold higher than that in the contralateral tumor. Growth of gadolinium-infused tumors was significantly inhibited compared to that of control tumors (P < 0.05) between the 16th and 23rd days after treatment.

Phenotypic modulation of smooth muscle cells in intima-media incorporated hybrid vascular prostheses

Hierarchical hybrid vascular grafts were constructed with an endothelial cell (EC) monolayer and hybrid medial layer composed of smooth muscle cells (SMCs) and type I collagen gel. The grafts, implanted into canine carotid arteries for up to 12 weeks, were ultrastructurally examined with a transmission electron microscope. Before implantation, SMCs incorporated into hybrid media were round and intracellularly filled with synthetic organelles such as rough endoplasmic reticula, mitochondria, free ribosomes, and Golgi complexes. Two weeks after implantation, bipolar spindle shaped SMCs still remained in a synthetic phenotype. At 12 weeks, circumferentially aligned SMCs were abundant in contractile apparatus such as myofilaments, dense bodies, and basement membranes. In a morphometric evaluation, the populations of three phenotypic SMCs (synthetic, intermediate, and contractile SMCs) were quantified. At 2 weeks, the proportions were 50.5, 41.8, and 7.7% for synthetic, intermediate, and contractile phenotypes, respectively. At 12 weeks, they were 9.9, 26.2, and 63.8%. These findings indicated that SMCs incorporated into hybrid grafts were transformed from a synthetic to a contractile phenotype under pulsatile stressed conditions after 12 weeks in vivo. Thus, the intima/media incorporated hybrid graft reconstructed a vessel wall similar to a native one in terms of structure and function.