Midday exposure to bright light changes the circadian organization of plasma melatonin rhythm in humans

Effects of bright light exposure at midday were examined on plasma melatonin rhythm in humans under controlled living conditions. Bright light of 5000 1x was provided from the ceiling at midday (1100-1700 h) for 3 consecutive days and the circadian rhythm in plasma melatonin was determined from the fourth to fifth day. The control study was performed in the same subjects who spend four days under dim light conditions (less than 200 1x). The subjects were allowed to sleep from 2400 to 0800 h. The onset phase, but not the end phase, of plasma melatonin rhythm was significantly phase-advanced by bright light exposure. Furthermore, the area under the curve of nocturnal melatonin rise was significantly larger under bright light exposure than under dim light. These findings indicate that midday exposure to bright light for 3 consecutive days changes the circadian organization of plasma melatonin rhythm in humans.

Vitamin B12 enhances the phase-response of circadian melatonin rhythm to a single bright light exposure in humans

Eight young males were subjected to a single blind cross-over test to see the effects of vitamin B12 (methylcobalamin; VB12) on the phase-response of the circadian melatonin rhythm to a single bright light exposure. VB12 (0.5 mg/day) or vehicle was injected intravenously at 1230 h for 11 days, which was followed by oral administration (2 mg x 3/day) for 7 days. A serial blood sampling was performed under dim light condition (less than 200 lx) and plasma melatonin rhythm was determined before and after a single bright light exposure (2500 lx for 3 h) at 0700 h. The melatonin rhythm before the light exposure showed a smaller amplitude in the VB12 trial than in the placebo. The light exposure phase-advanced the melatonin rhythm significantly in the VB12 trail, but not in the placebo. These findings indicate that VB12 enhances the light-induced phase-shift in the human circadian rhythm.

Aging affects development and persistence of feeding-associated circadian rhythm in rat plasma corticosterone

Effects of aging on development and persistence of feeding-associated circadian rhythm were examined with respect to the prefeeding plasma corticosterone peak under restricted feeding. Old (20 mo), middle-aged (12 mo), and young (2.5 mo) male rats were subjected to a restricted feeding schedule for 21 days in which free access to food was limited to 2 h/day in the light phase. Prefeeding corticosterone peak was detected 1 wk after the start of the schedule in the young and 3 wk after in the old and middle-aged rats. After the restricted feeding, a feeding/ fasting cycle composed of 7 days of ad libitum feeding and 3 days of fasting was imposed four times. The persistence of feeding-associated rhythm was evaluated by examining the reappearance of the corticosterone peak at the previous meal time during each fasting period of the feeding/fasting cycle. The corticosterone peak was not detected in the old and middle-aged rats even at the first cycle, but it was still distinct at the third cycle in the young rats. In conclusion, aging impaired the development and persistence of feeding-associated circadian rhythm in rats.

Diminished interferon-gamma (IFN-gamma) production by bacterial antigen-specific T cells in atopic patients

In this study, we established and studied cytokine production of T cell lines (TCL) specific to either a purified protein derivative of Mycobacterium tuberculosis (PPD) or Dermatophagoides farinae (Df) from atopic patients and non-atopic healthy subjects. IFN-gamma was detected in the culture supernatants of all of 36 PPD-specific TCL established from healthy controls, whereas only 24 of 38 PPD-specific TCL from patients produced IFN-gamma. Furthermore, the amounts of IFN-gamma produced by PPD-specific TCL from patients were significantly lower than those from healthy controls. No IL-4 was detected in any PPD-specific TCL from either healthy controls or atopic patients. The amounts of IL-4 production from Df-specific TCL from atopic patients were much higher than from healthy controls, while few TCL produced IFN-gamma. These results suggest that the skewing to the Th2-type T cell response in atopic patients is a response not only to allergens, but also to bacterial antigens, compared with non-atopic subjects. Activation of PPD-specific TCL from patients with calcium ionophore A23187 plus phorbol myristate acetate resulted in much higher IFN-gamma production than in TCL established from healthy controls, indicating that the low production of IFN-gamma by PPD-specific T cells from atopic patients is not due to an intrinsic T cell defect but to some regulatory mechanisms.

Intertrabecular pattern of tumors metastatic to bone

BACKGROUND

The prevalence of radiologically invisible metastatic tumors to bone is not known. To clarify this, the authors examined histologic sections, radiographs, bone scans, and magnetic resonance (MR) images of autopsied patients with bone metastases.

METHODS

Complete slices of the vertebral column, including C3-S1, were obtained from 52 cadavers with metastatic tumors to the spine. Macroscopic and histologic features were compared with postmortem roentgenographs (52 patients), bone scans with 99mTc-labelled methylene diphosphonate (17 patients), and MR images (4 patients). Morphologic patterns were classified into intertrabecular, osteoblastic, osteolytic, mixed, small lesion, and compression fracture.

RESULTS

Metastatic lesions were found in 734 of the 1194 vertebral bodies. The lesions were intertrabecular in 255 vertebrae, osteoblastic in 185, osteolytic in 114, mixed in 70, small lesion in 83, and compression fracture in 27. Postmortem radiographs demonstrated lesions in 367 (50%) of the 734 vertebrae, bone scans in 103 (34.7%) of the 297 vertebrae examined, and MR images in all 42 (100%) vertebral bodies imaged. Lesions showing an intertrabecular pattern were detected in only 7.1% of the radiographs and 4.5% of the bone scans.

CONCLUSIONS

Radiographs and bone scans often fail to show metastatic lesions, especially those with an intertrabecular pattern. The intertrabecular pattern is a unique histologic form that is difficult to detect on radiographs and bone scans.

Persistence of circadian oscillation while locomotor activity and plasma melatonin levels became aperiodic under prolonged continuous light in the rat

In order to examine the mechanism for a loss of circadian rhythms in several functions under prolonged continuous light (LL), rats were blinded following LL over 5 months, and the mode of reappearance of circadian rhythms were analyzed in locomotor activity and plasma melatonin levels. Locomotor activity and plasma melatonin levels in individual rats became aperiodic after the exposure to LL. On the day of blinding, plasma melatonin levels showed circadian rhythms having a peak coincided with the activity time of locomotor rhythm which was restored after blinding. The time of melatonin peak was not related to the time of blinding (onset of darkness) nor to the initial time of blood sampling. Circadian rhythm in plasma melatonin levels reappeared faster than those in locomotor activity. The findings suggest that aperiodism developed in these functions under prolonged LL is not due to disruption of the circadian oscillation but to uncoupling of overt functions from the circadian pacemaker.

Circadian rhythm and response to light of extracellular glutamate and aspartate in rat suprachiasmatic nucleus

Extracellular concentrations of glutamate and aspartate were measured in the vicinity of rat suprachiasmatic nucleus (SCN) by means of in vivo microdialysis. The concentrations of both excitatory amino acids (EAAs) were higher during the dark phase than during the light under the light-dark cycle, showing pulsatile fluctuations throughout the day. When rats were released into the complete darkness, the 24-h pattern in the aspartate continued for at least one cycle, whereas that in the glutamate disappeared. The nocturnal increases in the EAA levels were not due to the increase of locomotor activity during the nighttime, because the 24-h rhythms were also detected in animals under urethan anesthesia. The patterns of extracellular EAA levels were changed when rats were released into the continuous light. Circadian rhythm was not detected in the glutamate, whereas the 24-h pattern was maintained in the aspartate with the levels increased to various extents. A 30-min light pulse given either at zeitgber time (ZT) 1 or ZT 13 elevated the EAA levels during the latter half of the light pulse, except glutamate by a pulse at ZT 1. The extracellular EAA levels in the vicinity of the rat SCN showed the circadian rhythm with a nocturnal peak and increased in response to the continuous light and a brief light pulse. The aspartate level is considered to be regulated by the endogenous circadian rhythm, but the glutamate levels seems to be modified by the light-dark cycle.

Dissociation of paraventricular NPY release and plasma corticosterone levels in rats under food deprivation

Extracellular neuropeptide Y (NPY) in the vicinity of the paraventricular nucleus (PVN) as well as NPY concentrations in the PVN were measured in rats under ad libitum feeding and 2-day and 10-day food deprivation. Plasma corticosterone levels were not changed by 2-day food deprivation but were increased by subsequent refeeding. In contrast, the extracellular NPY levels were increased by 2-day food deprivation and were decreased rapidly by refeeding. The NPY concentrations were also increased and increased further by refeeding. On the other hand, plasma corticosterone levels were elevated by 10-day food deprivation and were decreased by subsequent refeeding. The extracellular NPY levels were also increased by food deprivation and decreased gradually after refeeding. However, the postprandial levels were still elevated when plasma corticosterone levels were returned to the basal levels. The NPY concentrations were also increased and increased further by refeeding. The amount of food intake after refeeding was positively correlated with the extracellular NPY levels. It is concluded that extracellular NPY levels in the PVN do not necessarily covariate with plasma corticosterone levels in rats under food deprivation.

Methicillin-resistant Staphylococcus aureus and Candida albicans on denture surfaces

Infectious diseases caused by methicillin-resistant Staphylococcus aureus, MRSA, and Candida albicans are often serious in compromised hosts. We enumerated MRSA and C. albicans on denture surfaces and in saliva samples from 29 adults. Staphylococcus species, MRSA, and methicillin-resistant Staphylococcus epidermidis, MRSE, were detected on 17, 3, and 1 of the 29 denture surfaces, respectively. C. albicans were detected on 22 denture surfaces. All saliva samples from patients whose dentures carried Staphylococcus species and C. albicans were also found to contain both microorganisms. Adherence of isolated 3H labeled cells of MRSA and C. albicans to resin beads and saliva-coated resin beads was examined. Cells of both microorganisms adhered in significantly higher numbers to saliva-coated resin beads than to resin beads. The hydrophobicity of the MRSA isolated from denture surfaces varied from strain to strain; that of C. albicans strains was moderately high. The zeta potentials of MRSA isolates and of C. albicans isolates determined in KCI buffer were significantly low. The potential of the resin beads decreased after treatment with saliva. Two out of 5 MRSA strains were found to be inhibited in growth by oral Streptococcus, Actinomyces, and gram-negative bacterial strains, suggesting that some oral bacterial species play a role in inhibiting the colonization of Staphylococcus species. No isolates of C. albicans were inhibited in their growth by any of the oral bacteria tested. Isolates of MRSA and C. albicans coaggregated with Porphyromonas gingivalis and Fusobacterium nucleatum strains. Using denture cleaners every night for 2 weeks did not reduce numbers of Staphylococcus species or C. albicans organisms in saliva.

Melatonin rhythm is not shifted by lights that suppress nocturnal melatonin in humans under entrainment

Effects of a single light exposure on the circadian rhythm in plasma melatonin were, examined in young males to obtain the threshold of light intensity for suppressing the nocturnal melatonin level on the one hand and to understand the relationship between the light-induced phase shift of melatonin rhythm and the melatonin suppression on the other hand. Eight subjects spent 3 days in an experimental living facility where light intensity was set below 200 lx and were exposed to light for 3 h in the early morning on the 2nd day. The same procedure was repeated five times in each subject with an interval of at least 3 wk, and one of five light intensities was tested in each trial. As a result, nocturnal melatonin level was not suppressed by light of 200 lx but significantly suppressed by light of intensity > or + 500 lx. On the other hand, the circadian melatonin rhythm was not shifted by any light intensity up to 10,000 lx. It is concluded that the threshold of light intensity for suppressing the melatonin level is located between 200 and 500 lx in young Japanese males, and the threshold for phase shifting the circadian melatonin rhythm was much greater than that for suppressing the nocturnal melatonin level in humans under entrained conditions.

Radiologic and pathologic characteristics of mixed dust pneumoconiosis

Modern radiologic technology has to led to increased diagnostic efficacy and accuracy in demonstrating pulmonary changes secondary to occupational dust exposure. This article presents three cases of typical and two cases of atypical silicosis with rounded atelectasis as seen in computed radiographic (CR), computed tomographic (CT), and scintigraphic images and autopsied lung specimens. Chest radiographs revealed both small rounded and small irregular opacities. Small irregular opacities on chest radiographs often proved to be reticular or honeycomb patterns on CT scans. Irregular opacities seen on CR and CT images represented interstitial fibrotic or mixed dust fibrotic changes associated with the accumulation of birefringent particles and emphysematous change, as noted at histologic analysis. CT scans and scintigrams were useful for visualizing parenchymal abnormalities, especially fibrotic change, emphysematous change, and pleural abnormalities.

Prefeeding release of paraventricular neuropeptide Y is mediated by ascending noradrenergic neurons in rats

The neuronal system responsible for the release of neuropeptide Y (NPY) in the paraventricular nucleus (PVN) was examined in rats under food deprivation and restricted daily feeding (RF). The ascending noradrenergic bundle (NAB) of neurons from the brain stem were destructed by microinjection of 6-hydroxydopamine (6-OHDA), and the extracellular NPY level in the PVN was measured by push-pull perfusion. 6-OHDA significantly reduced the extracellular norepinephrine level in the PVN to 15% of the control value when injected into the PVN and to 40% when injected into the midbrain ventral NAB. 6-OHDA administration into the NAB affected neither the deprivation-induced increase nor the feeding-induced decrease in the extracellular NPY. The amount of food intake after refeeding was not changed by the 6-OHDA treatment. On the other hand, 6-OHDA injection into the PVN or NAB not only decreased the extracellular NPY level, the amount of food intake was not change by the 6-OHDA treatment. It is concluded that the NAB is involved in the prefeeding NPY release in rats under RF but not in the deprivation-induced NPY release.

Establishment and characterization of ovalbumin-specific T cell lines from patients with egg allergy

In order to investigate T cell recognition of allergens in hen egg allergy, we have established 30 ovalbumin (OVA)-specific T cell lines (TCLs) from peripheral blood mononuclear cells of 6 patients with atopic dermatitis, who are positive for IgE antibodies to OVA and clinically allergic to hen egg, and characterized them for their cytokine production pattern. All TCLs we could study were mainly composed of CD4+ T cells. Most TCLs produced significant amounts of interleukin 4 (IL-4) and IL-5 but no or very little interferon gamma on antigen stimulation, suggesting that these TCLs belong to TH2-type T cells. Restriction elements and epitope specificities were further studied on some TCLs. Antibody blocking of the proliferative responses of the TCLs to OVA indicated that HLA-DR are acting as the dominant restriction elements for these TCLs with minor contribution of HLA-DQ. By use of 187 overlapping synthetic peptides covering the whole sequence of OVA, at least 3 different T cell epitopes were identified.

Effects of restricted daily feeding on neuropeptide Y release in the rat paraventricular nucleus

Extracellular neuropeptide Y (NPY) in the vicinity of the paraventricular nucleus (PVN) and the NPY concentrations in the PVN, arcuate nucleus of the hypothalamus (ARC), and the nucleus tractus solitarius (NTS) were measured in rats under ad libitum and restricted daily feeding (RF) where meal was supplied at a fixed time of day. The extracellular NPY levels did not vary significantly between 0600 and 2200 in rats under ad libitum feeding but were increased before meal and decreased immediately after mean supply under the RF regimen. Similarly, the NPY concentrations in the PVN, ARC, and NTS were increased immediately before meal. When meal was omitted at the regular mealtime, the extracellular NPY levels were not decreased rapidly, and the NPY concentration in the PVN remained at a low level. Rats were subjected to the feeding-fasting paradigm after the termination of RF. The extracellular NPY levels were returned to basal levels during the feeding period but were elevated during the fasting period at almost the same time as that for meal supply under the RF regimen. It is concluded that the prefeeding enhancement of the NPY release in the PVN under the RF regimen is regulated by the feeding-associated circadian rhythm.

Allergenic epitopes of ovalbumin (OVA) in patients with hen's egg allergy: inhibition of basophil histamine release by haptenic ovalbumin peptide

We studied allergenic determinants that induce hypersensitivity to OVA, the major allergen in egg allergy, using immunoblot and histamine release assays. Immunoblot analysis demonstrated a part of the OVA epitope was in the C-terminal region comprising residues 347-385 (OVA347-385). Histamine was released from basophils of a patient with egg allergy upon stimulation with the OVA fragment corresponding to OVA347-385. Furthermore, detailed epitope mapping using overlapping peptides (residues 347-366, OVA-A; residues 357-376, OVA-B; and residues 367-385, OVA-C) in the OVA 347-385 region was carried out using the histamine release assay. In order for histamine release from basophils to occur, the allergen must possess two or more allergenic determinants located on the protein molecule at distances that would be equivalent to the distances between IgE molecules on the membrane surface. these results suggest that there are at least two epitopes that bind IgE antibodies on each OVA peptide. In addition, one epitope that binds IgE antibodies in two patients appears to reside in the haptenic peptide OVA357-366 (OVA-B1). The histamine release from basophils stimulated by OVA-B was completely inhibited by OVA-B1 in one of these patients. Similarly, OVA-B1 inhibited the histamine release produced by OVA-A in the other by more than 40%. These results suggest that haptenic synthetic peptides could regulate the allergic reaction in the effector phase if common epitope(s) recognized by IgE antibodies in the patients with egg allergy can be found. These are the first studies that provide an antigen-specific approach to inhibiting histamine release from basophils by a haptenic peptide recognized by IgE antibodies in an allergic disorder.

Indications of breast preserving surgery without radiation

Breast preserving surgery has become a standard therapy for early breast cancer. Breast conserving therapy with radiation has been recognized as a standard strategy, because of the low incidence of local failure and minimal postoperative deformity compared with that of quadrantectomy without radiation. Among cases treated with breast preserving surgery, surgical resection alone may be sufficient for local control. We have experienced 11 cases of local failure from 108 cases who were treated with quadrantectomy. The ability of local control with quadrantectomy was analized. Among 11 cases with local failure, 3 cases had an apparently small resection area, and 3 cases had multiple tumors. In the other five cases, intraductal component was observed in primary tumor, 2 out of the five cases had EIC, and 3 of the five cases relapsed around the areola. After close analysis and modification of indication criteria, we could reduce the recurrence rate of late 66 cases to less than 2%. For local failure cases, seven cases were treated with total mastectomy, 4 with partial mastectomy, and no further relapse resulted. Our data indicated that quadrantectomy is effective and safe for local control if its indication is carefully determined.

Substance P receptor regulates the photic induction of Fos-like protein in the suprachiasmatic nucleus of Syrian hamsters

Substance P (SP) is a candidate neurotransmitter or neuromodulator for conveying light information from the retina to the hypothalamic suprachiasmatic nucleus (SCN) where a circadian oscillator(s) is located in mammals. Immediate early gene c-fos has been demonstrated to be induced in the SCN with a brief light exposure at the subjective night, and suggested to play an important role in the photic entrainment of the oscillator. To clarify the possibility of an involvement of the SP receptor in the photic-induction of c-fos in the SCN, we examined effects of a SP receptor antagonist, spantide, on the light-induced Fos-like protein immunoreactivity (Fos-lir) in the SCN of Syrian hamster. The light-induced Fos-lir was inhibited with the pretreatment of spantide in a dose-related manner and in an anatomically distinctive way. The higher dose of spantide (8 nmol) blocked light-induced Fos-lir substantially in the rostral and central areas of the SCN, and in the dorsal portion of the caudal SCN. However, it blocked Fos-lir only slightly in the ventral portion of the caudal SCN. These results suggest that the SP is involved in conveying light information to induce Fos protein in the hamster SCN, and that different neurotransmitter systems are involved in the light-induced Fos-lir in the different portions of hamster SCN.

[Comparison between retrograde cerebral perfusion and selective cerebral perfusion by intraoperative electroencepharogram]

We used retrograde cerebral perfusion (RCP) to protect the brain in patients undergoing aortic arch replacement from May 1991 to July 1992. Subsequently, we have been using selective cerebral perfusion (SCP). In this study, a group of six patients undergoing RPC were compared with 5 patients undergoing SCP with regard to the intraoperative electroencepharogram (EEG) and post operative clinical course. There were no deaths in either group, but transient palsy of the right arm developed in one patient in the RCP group. The amplitude of intraoperative EEG was examined at four points: before cardiopulmonary bypass, during RCP or SCP, at 30 degrees C and at 35 degrees C during rewarming. The EEG amplitude at these four points was expressed as a ratio to the value before cardiopulmonary bypass. The ratios at these four points were 1, 0, 0.08, and 0.19 in the RCP group and 1, 0, 0.70, and 0.90 in the SCP group, respectively. In the SCP group, EEG recovered rapidly, whereas in the RCP group EEG did not recover until the completion of cardiopulmonary bypass in all but one patient. These results indicated that RCP does not provide reliable protection of the brain.

Methamphetamine stimulates the release of neuropeptide Y and noradrenaline from the paraventricular nucleus in rats

Effects of methamphetamine (MAP) on the extracellular neuropeptide Y (NPY) and noradrenaline (NA) levels were examined in the vicinity of the paraventricular nucleus (PVN) of freely moving rats by means of push-pull perfusion. The NA and NPY levels increased significantly in 30-60 min and reached the maximum level in 90-120 min after intraperitoneal administration of MAP. The effects were dose-dependent. The maximum levels were 1.6-fold of the pretreatment level for NPY and 7-fold for NA, respectively, when 5.0 mg/kg b.w. of methamphetamine was administered. It is concluded that MAP stimulates the releases of paraventricular NPY and NA, but the effect is more strong for NA than for NPY.

A variant alkaline phosphatase detected in a patient with lung cancer

A variant alkaline phosphatase (ALP), with heat-sensitivity characteristics similar to that of the bone type, was found in the serum of a patient suffering from lung cancer. In disc polyacrylamide gel electrophoretic studies most of this enzyme had migrated to the region corresponding to liver ALP, with the remainder affecting bone ALP. Like kidney ALP, this ALP was markedly inhibited by 0.5 mmol/l L-cysteine. The K(m) of this ALP for p-nitrophenylphosphate was 0.39 mmol/l, similar to that of kidney ALP. The sugar moiety of this enzyme bore greater resemblance to that of kidney ALP than liver or bone ALP. However, immunoprecipitation of this particular ALP was strong with a monoclonal antibody against liver ALP and moderate with an antibody against bone ALP.

Two distinct oscillators in the rat suprachiasmatic nucleus in vitro

In the rat suprachiasmatic nucleus slice culture, circadian rhythms in the release of arginine vasopressin and vasoactive intestinal polypeptide were measured simultaneously and longitudinally. The phase relationship between the two peptide rhythms was relatively constant in the culture without a treatment of antimitotic drugs but became diverse by an introduction of antimitotics, which is generally used to reduce the number of glial cells. By monitoring the two rhythms continuously for 6 days, different periods were detected in culture with the antimitotic treatment. Furthermore, N-methyl-D-aspartate shifted the phase of the two peptide rhythms in the same culture differently. These results indicate that the arginine vasopressin and vasoactive intestinal polypeptide release are under control of different circadian oscillators.

Methylmalonic acidemia: brain lesions in a case of vitamin B12 non-responsive (mut0) type

Neuropathological findings were described in a 9-day-old female infant who died of the vitamin B12 non-responsive (mut0) type of methylmalonic acidemia (MMA). Widespread karyorhectic fragments of varying size and shape were noted throughout the brain, in particular densely accumulated in the cerebellar granular layers and the layer IV of the striate cortex. Bilateral or symmetrical necrotic foci were observed in various regions of the grey matter: Sommer's sector of the hippocampus, basal ganglia, thalamus, hypothalamus and brainstem. In the cerebral cortex small spongy necrotic foci were scattered mainly in the depths of gyri. Alzheimer type II astrocytes appeared in the preserved zone of the caudate nucleus. Myelinated nerve fibers in the brainstem were spongy or vacuolated, whereas peripheral myelin sheaths of cranial nerves were intact. Multiple hemorrhagic foci were noted in the cerebellum, predominantly the granular layers. The lymphoid tissue in the spleen and the thymus was hypoplastic. It may be difficult to explain exactly the mechanisms of the pathological changes observed here on routine light microscopy; the outcome of systemic ischemia/hypoxia before death cannot be completely ignored. But, it is suggested that widespread karyorhexis may occur selectively in specific cells (or cell groups), including immature neurons and other cellular components (glial and/or mesenchymal cells) among the patients with the mut0 type of MMA.