Pituitary metastasis: From pathology to clinical and radiological considerations

PURPOSE

A review of the literature with respect to pituitary metastases (PM) with clinical and radiological considerations are summarized to facilitate clinical decision making in the management of PM METHODS: A review of literature associated with PM and tumour to tumour metastases in the English literature was reviewed and summarized RESULTS: Pituitary metastases account for 1.0-3.6% of all surgically treated pituitary lesions. Often identified in parallel with extensive disseminated disease, once diagnosed, the prognosis is generally poor, although survival is highly heterogeneous and dependent on the primary tumor histology. Within this anatomical region is also the observation of tumor-to-tumor metastases and collision tumours. Both the tumor macro- and microenvironment play central roles to the progression of disease with distinctive radiological features that may suggest a metastatic sellar lesion as opposed to a primary pituitary lesion. Surgical resection is the first line of therapy followed by adjuvant chemoradiotherapy and endocrinological evaluation for hormonal supplementation CONCLUSION: PMs are relatively rare but important oncological entities representing disseminated disease in the majority of cases. Careful consideration of the relevant clinical history and radiological features can aid the clinician differentiate between a metastatic lesion to the pituitary region and a primary pituitary tumor. While surgical resection is first line therapy, stereotactic radiosurgery in carefully selected patients is emerging as a viable alternative.

[Investigation and analysis of tinnitus in diabetic patients]

Objective:To analyze the influencing factors of tinnitus in diabetic patients and the correlation between hearing loss and tinnitus.Method:Participants were patients with diabetes. Subjects were tested for hearing function and tinnitus symptoms by questionnaire and pure tone audiometry.Result:①112 patients (55 were men and 57 were women) were affected by tinnitus symptoms in 255 patients with diabetes，there were no significant differences between the number of male patients and female patients(P=0.278).②The incidence of tinnitus increased with age (≤30 year: 40%, 31-40 year :25%, 41-50 year: 27%, 51-60 year: 43%, >60 year: 55%),and there was significant differences in the number of patients among different age (P=0.001).③The incidence of tinnitus was no significant difference in diabetes patients with different educational level (P=0.648).④Totally 83 subjects who complained hearing impairment were tested for hearing loss by pure tone audiometry, while 113 (66%) of 172 subjects who insisted their hearing were normal had hearing loss. Of the subjects with normal hearing but tinnitus, 72% had hearing loss and 62% of patients without tinnitus actually had hearing loss.⑤There were statistically significant in patients with diabetes between the incidence of tinnitus and low/intermediate frequency hearing loss or high frequency hearing loss.Conclusion:The incidence of tinnitus symptoms is increased in patients with diabetes mellitus, which may be related to the age, the incidence of hearing loss,however, may be irrelevant to gender and educational level. Diabetic patients with tinnitus symptoms should be tested as soon as possible to achieve early intervention.

Population pharmacokinetics and Bayesian estimation of tacrolimus exposure in Chinese liver transplant patients

WHAT IS KNOWN AND OBJECTIVES

Tacrolimus (TAC) is widely used as part of immunosuppressive regimens. There is great interindividual variation on the disposition of TAC. The aim of this study was to develop a population pharmacokinetic (PPK) model for Chinese liver transplant patients and evaluate genetic polymorphism and other possible factors on the PK parameters. The exposure of TAC is to be estimated through Bayesian modelling.

METHODS

A total of 47 sets of rich-time PK and 1234 conventional therapeutic drug monitoring (TDM) data were collected from 125 Chinese liver transplant patients. The pathophysiological data of these patients were recorded. CYP3A5*3 and ABCB1 genotypes were determined for each patient. The PPK model for TAC was established by nonlinear mixed-effects modelling (nonmem). The impact of pathophysiology and genotype on PPK parameters was evaluated. Bayesian estimators for the area under concentration-time curve (AUC) of TAC were validated.

RESULTS

A two-compartment model with lag time was found to be the most suitable model for the pooled full PK and TDM data for Chinese liver transplant patients. The CL/F, V₂ /F, Q/F, V₃ /F, K_a and lag time were 17.4±0.81 L/h, 165±44.1 L, 54.9±25.8L/h, 594±87.5 L, 0.51±0.095 L/h and 1.57±0.34 h. Post-operative day (POD), creatinine clearance (CLcr) and ABCB1 C3435T genotypes were found to have significant influences on CL/F (P<.01). ABCB1 C3435T genotypes showed a significant correlation with V₂ /F (P<.01). C₀ -C₂ and C₀ -C₂ -C₄ were shown to be suitable for the estimation of AUC in Chinese liver transplant patients.

WHAT IS NEW AND CONCLUSION

A PPK model for TAC was established successfully in Chinese liver transplant patients. POD, CLcr and ABCB1 C3435T genotypes were shown to have significant effects on CL/F. The AUC of TAC in Chinese liver transplant patients could be estimated through Bayesian modelling, based on which individualized immunosuppressive regimens can be designed.

Brain microbiota disruption within inflammatory demyelinating lesions in multiple sclerosis

Microbial communities reside in healthy tissues but are often disrupted during disease. Bacterial genomes and proteins are detected in brains from humans, nonhuman primates, rodents and other species in the absence of neurological disease. We investigated the composition and abundance of microbiota in frozen and fixed autopsied brain samples from patients with multiple sclerosis (MS) and age- and sex-matched nonMS patients as controls, using neuropathological, molecular and bioinformatics tools. 16s rRNA sequencing revealed Proteobacteria to be the dominant phylum with restricted diversity in cerebral white matter (WM) from MS compared to nonMS patients. Both clinical groups displayed 1,200–1,400 bacterial genomes/cm³ and low bacterial rRNA:rDNA ratios in WM. RNAseq analyses showed a predominance of Proteobacteria in progressive MS patients’ WM, associated with increased inflammatory gene expression, relative to a broader range of bacterial phyla in relapsing-remitting MS patients’ WM. Although bacterial peptidoglycan (PGN) and RNA polymerase beta subunit immunoreactivities were observed in all patients, PGN immunodetection was correlated with demyelination and neuroinflammation in MS brains. Principal component analysis revealed that demyelination, PGN and inflammatory gene expression accounted for 86% of the observed variance. Thus, inflammatory demyelination is linked to an organ-specific dysbiosis in MS that could contribute to underlying disease mechanisms.

GABA transport and neuroinflammation are coupled in multiple sclerosis: regulation of the GABA transporter-2 by ganaxolone

Interactions between neurotransmitters and the immune system represent new prospects for understanding neuroinflammation and associated neurological disease. GABA is the chief inhibitory neurotransmitter but its actions on immune pathways in the brain are unclear. In the present study, we investigated GABAergic transport in conjunction with neuroinflammation in models of multiple sclerosis (MS). Protein and mRNA levels of γ-amino butyric acid transporter 2 (GAT-2) were examined in cerebral white matter from MS and control (Non-MS) patients, in cultured human macrophages, microglia and astrocytes, and in spinal cords from mice with and without experimental autoimmune encephalomyelitis (EAE) using western blotting, immunocytochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). GABA levels were measured by HPLC. The GAT-2's expression was increased in MS patients' (n=6) white matter, particularly in macrophage lineage cells, compared to Non-MS patients (n=6) (p<0.05). Interferon-γ (IFN-γ) stimulation of human macrophage lineage cells induced GAT-2 expression and reduced extracellular GABA levels (p<0.05) but soluble GABA treatment suppressed HLA-DRα, GAT-2 and XBP-1/s expression in stimulated macrophage lineage cells (p<0.05). Similarly, the synthetic allopregnanolone analog, ganaxolone (GNX), repressed GAT-2, JAK-1 and STAT-1 expression in activated macrophage lineage cells (p<0.05). In vivo GNX treatment reduced Gat-2, Cd3ε, MhcII, and Xbp-1/s expression in spinal cords following EAE induction (p<0.05), which was correlated with improved neurobehavioral outcomes and reduced neuroinflammation, demyelination and axonal injury. These findings highlight altered GABAergic transport through GAT-2 induction during neuroinflammation. GABA transport and neuroinflammation are closely coupled but regulated by GNX, pointing to GABAergic pathways as therapeutic targets in neuroinflammatory diseases.

Electrical performances and structural designs of copper bonding in wafer-level three-dimensional integration

The integrity of bonded Cu interconnects in wafer-level three-dimensional integration has been investigated as the function of pattern size and density, as well as bonding process parameter. The desired pattern density coupled with the application of bonding process profile we developed gives optimal yield and alignment accuracy, and provides excellent electrical connectivity and contact resistance through the entire wafer. This result is a key milestone in establishing the manufacturability of Cu-based interconnections for 3D integration technology.

Fabrication of nano-scale Cu bond pads with seal design in 3D integration applications

A method to fabricate nano-scale Cu bond pads for improving bonding quality in 3D integration applications is reported. The effect of Cu bonding quality on inter-level via structural reliability for 3D integration applications is investigated. We developed a Cu nano-scale-height bond pad structure and fabrication process for improved bonding quality by recessing oxides using a combination of SiO2 CMP process and dilute HF wet etching. In addition, in order to achieve improved wafer-level bonding, we introduced a seal design concept that prevents corrosion and provides extra mechanical support. Demonstrations of these concepts and processes provide the feasibility of reliable nano-scale 3D integration applications.

Observation of fluorescence emissions from single-bubble sonoluminescence in water doped with quinine

Sonoluminescence is a phenomenon involving the transduction of sound into light. The detailed mechanism as well as the energy-focusing potentials are not yet fully explored and understood. So far only optical photons are observed, while emissions in the ultra-violet range are only inferred. By doping the fluorescent dye quinine into water with dilute sulphuric acid, the high energy photons can be converted into the optical photons with slower decay constants. These sonoluminescence and fluorescent emissions were observed in coincidence, and the emitted signals of the two modes can be differentiated by their respective timing profiles. Plans for using this technique as a diagnostic tool to quantitatively study ultra-violet and other high energy emissions in sonoluminescence are discussed.

Radiation dosimetry estimates for the PET serotonin transporter probe 11C-DASB determined from whole-body imaging in non-human primates

The radiotracer 3-amino-4-(2-dimethylaminomethyl-phenylsulfanyl)-benzonitrile labelled in the N-methyl position (11C-DASB) is a selective radioligand for the in vivo quantification of serotonin transporters (SERTs) using positron emission tomography (PET). The current study quantified the distribution of activity in two rhesus monkeys after the injection of approximately 333 MBq (9 mCi) 11C-DASB. Whole-body images were acquired at 22 time points for a total of 120 min following injection of the radioligand. Source organs were identified at each time point from both tomographic images (using multiple regions of interest on each tomograph for each organ) and a single planar image (using a single region of interest for each organ). The peak activities in planar images in the five identified source organs (expressed as per cent injected dose (ID)) were lungs (24% ID at 1.5 min), kidneys (6.5% ID at 4 min), liver (8% ID at 3 min), brain (4% ID at 5 min) and spleen (0.42% ID at 3 min). Mono-exponential fitting of activity overlying the bladder suggested that approximately 14% of activity was excreted via the urine. The radiation burden to the body was calculated from residence times of these source organs and then scaled to corresponding human values. The calculated effective dose from tomographic and planar images was 6.0 and 6.4 microGy x MBq(-1) (22.3 and 23.7 mrad x mCi(-1)), respectively. The planar analysis was much easier to perform, and generally yielded slightly higher (i.e., more conservative) estimates of radiation burden than the tomographic analysis. The estimated radiation burden of 11C-DASB is relatively modest and would allow multiple scans per research subject per year.

The pharmacokinetics of lignocaine in humans during a computer-controlled infusion

Several types of chronic pain syndromes are effectively treated with sodium channel blockers such as lignocaine. Further investigation of this therapeutic modality would be facilitated by refinement of the parameters describing lignocaine distribution and elimination. This would allow precise lignocaine infusion by a computer-controlled infusion to attain and maintain stable target lignocaine concentrations. Arterial blood samples were obtained at frequent intervals during a computer-controlled infusion of lignocaine in 12 adult human volunteers. Plasma lignocaine concentrations of 1, 2, 3, 4 and 5 microg/ml were targeted for 15 min at each concentration. A three-compartment mammillary pharmacokinetic model best described the resulting concentration vs time profile. A population pharmacokinetic analysis was performed using three different techniques; the two-stage, pooled and mixed effects modelling. There was marked overshoot of the plasma concentration above the target prior to refinement of the pharmacokinetic parameters. The best parameters of a three-compartment mammillary model fit to the measured concentration using the pooled data approach were: V(1) = 7.44, V(2) =11.5 and V(3) = 97.71; Cl(1) = 0.585, Cl(2) = 2.23 and Cl(3) =1.64 l/min. Similarly calculated parameters using NONMEM were V(1) = 6.99, V(2) =12.2 and V(3) =1341; Cl(1) = 0.703, Cl(2) =1.24 and Cl(3) =1.49 l/min. The addition of age as a covariate of the pharmacokinetic parameters improved the model in both cases. Height, lean body mass and body surface area as covariates of the pharmacokinetic parameters did not improve the predicted value of the model. Prospective testing of the pharmacokinetic parameters will be required to define whether they function well. The refinement of pharmacokinetic parameters for the computer-controlled intravenous infusion of lignocaine will facilitate further research in pain therapy. Published lignocaine pharmacokinetic values have a relatively large central volume of distribution, and hence, when implemented as a computer-controlled infusion, result in dramatic overshoot shortly after targeting a higher plasma concentration. In light of the long-lasting pain relief provided by sodium channel blockade in neuropathic pain states, overshoot of plasma concentrations must be avoided if the concentration vs effect relationship is to be defined.

Somatostatin modulates the behavioral effects of dopamine receptor activation in parkinsonian rats

Somatostatin may play a role in several neuropsychiatric disorders, including Parkinson's disease. Although functional interactions between somatostatinergic and dopaminergic transmitter systems have been well documented, no study has been conducted in animals with experimental Parkinsonism to explore the effects of somatostatin on dopamine receptor-mediated behavior. In the present study, rats with unilateral 6-hydroxydopamine-induced destruction of the medial forebrain bundle were assessed following administration of the dopamine(1/2) receptor agonist apomorphine. Ipsilateral intrastriatal infusion of somatostatin produced a dose-related inhibition of apomorphine-induced rotations with maximal effect at a dose of 7.5 microg in 2 microl. This inhibitory effect of somatostatin was antagonized by the somatostatin antagonist cyclo-somatostatin (0.1 microg in 2 microl, intrastriatally). Neither somatostatin (up to 15 microg in 2 microl) nor cyclo-somatostatin on its own induced rotations; similarly, this dose of cyclo-somatostatin did not affect apomorphine-induced rotations. From these results we suggest that exogenous somatostatin, by directly acting on its specific receptors in the striatum, inhibits the effects of dopamine receptor activation in parkinsonian rats. We conclude that therapies based on modulation of somatostatin may be worth exploring in the management of Parkinson's disease and other disorders of the basal ganglia.

Biochemical variations in the synaptic level of dopamine precede motor fluctuations in Parkinson's disease: PET evidence of increased dopamine turnover

Motor fluctuations are a major disabling complication in the treatment of Parkinson's disease. To investigate whether such oscillations in mobility can be attributed to changes in the synaptic levels of dopamine, we studied prospectively patients in the early stages of Parkinson's disease with a follow-up after at least 3 years of levodopa treatment. At baseline, 3 positron emission tomography (PET) scans using [11C]raclopride before and after (1 hour and 4 hours) orally administered levodopa were performed on the same day for each patient. Patients who developed "wearing-off" fluctuations during the follow-up period had a different pattern of levodopa-induced changes in [11C]raclopride binding potential (BP) from that observed in patients who were still stable by the end of the follow-up. Thus, 1 hour post-levodopa the estimated increase in the synaptic level of dopamine was 3 times higher in fluctuators than in stable responders. By contrast, only stable responders maintained increased levels of synaptic dopamine in the PET scan performed after 4 hours. These results indicate that fluctuations in the synaptic concentration of dopamine precede clinically apparent "wearing-off" phenomena. The rapid increase in synaptic levels of dopamine observed in fluctuators suggests that increased dopamine turnover might play a relevant role in levodopa-related motor complications.

Biochemical variations in the synaptic level of dopamine precede motor fluctuations in Parkinson's disease: PET evidence of increased dopamine turnover

Motor fluctuations are a major disabling complication in the treatment of Parkinson's disease. To investigate whether such oscillations in mobility can be attributed to changes in the synaptic levels of dopamine, we studied prospectively patients in the early stages of Parkinson's disease with a follow-up after at least 3 years of levodopa treatment. At baseline, 3 positron emission tomography (PET) scans using [11C]raclopride before and after (1 hour and 4 hours) orally administered levodopa were performed on the same day for each patient. Patients who developed "wearing-off" fluctuations during the follow-up period had a different pattern of levodopa-induced changes in [11C]raclopride binding potential (BP) from that observed in patients who were still stable by the end of the follow-up. Thus, 1 hour post-levodopa the estimated increase in the synaptic level of dopamine was 3 times higher in fluctuators than in stable responders. By contrast, only stable responders maintained increased levels of synaptic dopamine in the PET scan performed after 4 hours. These results indicate that fluctuations in the synaptic concentration of dopamine precede clinically apparent "wearing-off" phenomena. The rapid increase in synaptic levels of dopamine observed in fluctuators suggests that increased dopamine turnover might play a relevant role in levodopa-related motor complications.

Optical properties of porcine skin dermis between 900 nm and 1500 nm

The weak absorption of shortwave infrared light by skin tissues between 700 and 1500 nm offers an important window for diagnosis by optical means. The strong scattering of shortwave infrared light by the skin, however, presents a challenge to the modelling of light propagation through the skin and the understanding of skin optics. We have measured the collimated and diffuse transmittance and diffuse reflectance of porcine skin dermis samples within 30 h post-mortem. Monte Carlo simulations have been performed to inversely determine the absorption coefficient, scattering coefficient and anisotropy factor of the dermis samples in the spectral range from 900 to 1500 nm. We further analyse the sensitivity of the values of the parameters to the experimental errors and inverse calculation procedures. The state of the cellular integrity of the skin samples following optical measurements was verified using transmission electron microscopy. These results were correlated to study post-mortem effects on the in vitro optical properties of porcine dermis. We concluded that for samples stored within crushed ice for up to 30 h post-mortem the wavelength dependence of optical properties of the dermis remains unchanged while the values of the parameters vary moderately due to modification of the water content of the tissue.

Modeling of the rough-interface effect on a converging light beam propagating in a skin tissue phantom

Light distribution in a strong turbid medium such as skin tissue depends on both the bulk optical properties and the profiles of the interfaces where mismatch in the refractive index occurs. We present recent results of a numerical investigation on the light distribution inside a human skin tissue phantom for a converging laser beam with a wavelength near 1 mum and its dependence on the roughness of the interfaces and index mismatch. The skin tissue is modeled by a two-layer structure, and within each layer the tissue is considered macroscopically homogeneous. The two interfaces that separate the epidermis from the ambient medium and the dermis are considered randomly rough. With a recently developed method of Monte Carlo simulation capable of treating inhomogeneous boundary conditions, light distributions in various cases of interface roughness and index mismatch are obtained, and their relevance to the measurements of optical parameters of the skin tissue and laser surgery under the skin surface are discussed.

HPV6b virus like particles are potent immunogens without adjuvant in man

Subjects with genital warts were immunized three times or more with HPV6b VLPs without adjuvant. All immunized subjects had DTH to HPV6b L1 protein. Of 32 subjects, nine had HPV6b specific antibody prior to immunization and 22 acquired antibody with immunization. VLP specific antibody increased following a single immunization in 6 of 8 subjects with low level antibody at recruitment. Complete regression of genital warts was observed in 25 of 33 evaluable subjects over the 20-week observation period. We conclude that immunization with HPV6b L1 VLPs without adjuvant induces immunity to the L1 protein epitopes recognised during natural infection, and may accelerate regression of warts.

Monte carlo simulation of converging laser beams propagating in biological materials

A new method of Monte Carlo simulation has been developed to simulate the spatial distribution of photon density of converging laser beams propagating in a turbid medium such as the phantom of biological tissue. This method can be used to obtain steady-state light distribution in the tissue phantom for a continuous-wave laser beam. We have calculated the steady-state distribution of the photon density and found important features that are uniquely related to the propagation of the converging beams in the tissue phantom.

Alterations of T-lymphocyte subsets, soluble IL-2 receptor, and IgE in peripheral blood of children with acute asthma attacks

BACKGROUND

T-cell activation and alteration of cytokines are involved in the pathogenesis of atopic asthma. However, the profile of circulating T-lymphocyte subsets, related cytokines, and plasma IgE during acute asthma attacks is still unclear.

OBJECTIVE

In an attempt to illustrate the dynamics of these parameters in asthma attacks, we investigated the changes of T-cell subsets, lymphocyte activation, soluble IL-2R, and IgE in peripheral blood in children during and after acute asthma attacks.

METHODS

This study was carried out in a cohort of Chinese children (n = 59) with acute asthma attacks. Immunoassays were performed when the patients had acute attacks before treatment, and the patients were reexamined in the 4 weeks after the resolution of acute attacks with therapy. Paired t tests were used for the statistical analysis of these patients to compare the data obtained during and after the acute attacks. Twenty healthy, age-matched subjects were used as normal control subjects. Nine children with long-term stable asthma were used as control subjects with stable asthma.

RESULTS

CD3+, CD4+, CD8+, and IL-2R+ (CD25+) cells; plasma soluble IL-2 receptor; and IgE were significantly higher in patients with acute attacks than in control subjects. (P <.05, P <.05, P <.001, P <.05, P <.0001, and P <.0001, respectively). Immunoelectron microscopy exhibited an increased expression of IL-2R on lymphocytes in acute attacks as compared to control subjects. The abnormalities returned to normal, with the exception of IgE, when clinical remission was achieved after treatment. Correlation analyses revealed a positive relationship between plasma IgE and soluble IL-2R in asthma attacks (r = 0.83, P =.0001). Plasma IgE and soluble IL-2R of those who were in remission positively correlated with their production in acute attacks (r = 0.58, P =.001 and r = 0.71, P =.0001, respectively).

CONCLUSION

This study suggests that (1) the percentage of CD4+, CD8+, or IL-2R+ lymphocytes in peripheral blood was significantly elevated during acute attacks and returned to normal ranges after complete remission was achieved; (2) plasma soluble IL-2R is a sensitive marker for asthma activity; and (3) atopic asthmatic children seem to have a hereditary predisposition of having higher levels of soluble IL-2R in asthma attacks, coinherited with the trait of IgE.

[Repair of vagina with segment of vascularized ileal graft following pelvic exenteration for carcinoma of rectum]

OBJECTIVE

To introduce a method to repair the vagina following pelvic exenteration for carcinoma of rectum in which the posterior wall of the vagina and cervix of the uterus were often involved.

METHODS

From 1990 to 1997 segment of the vascularized ileum was used to repair the vagina in 5 cases, and in 2 of which the whole vagina was repaired while in the other 3 cases only the posterior wall of the vagina was repaired.

RESULTS

All of the patients had successful results after operation repair.

CONCLUSION

Vascularized graft was an ideal material for the repair of vagina defect following pelvic exenteration for carcinoma of rectum, because this material was easily accessible, and its vascular pedicle was long enough for its transferring to the perineal region and the ileum had good blood supply which made healing easy. The vagina following repair had a thick posterior wall, good elasticity and very little scar tissue surrounded.

Circadian and circannual rhythms in the function of central 5-HT1A receptors in laboratory rats

In order to elucidate whether a circannual rhythm exists in the function of the central serotonin (5-HT) system, we examined the responsiveness of rats to a selective 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), at different hours of the day in different seasons. The results indicate that both a circadian rhythm and a circannual rhythm exist in the responsiveness. The phases of the circadian rhythm exhibit 1-year period variations, while those of the circannual rhythm exhibit 1-day period variations. These results will help to clarify the disparities among the reports on circadian and circannual rhythms in the phenomenon related to the central 5-HT system.

Angular correlation function of speckle patterns scattered from a one-dimensional rough dielectric film on a glass substrate

We present the experimental results of the angular correlation function of far-field speckle patterns scattered by a one-dimensionally random rough surface of a thin dielectric film on a glass substrate when a polarized beam of light is incident upon the rough surface from vacuum. This surface, which separates the vacuum and the dielectric, is rough enough that only diffused speckles are observed. The experiment for the correlation measurement was set up to make use of a CCD camera to obtain the image of the speckle pattern in the specular direction for each given angle of incidence; the cross-correlation function is then calculated from the digitized images. It is found that the intensity correlation functions exhibit two distinct maxima: one arises from the autocorrelation and the other from the reciprocity condition. It is also found that different scattering processes give rise to quite different correlation functions: multiple-scattering processes produce narrow peaks with secondary maxima and single-scattering processes produce relatively broad peaks.

Circadian rhythm in the response to intracerebroventricular administration of 8-OH-DPAT

In a recent study, we observed circadian rhythms in the response to subcutaneous (s.c.) administration of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a serotonin (5-HT)1A receptor agonist, in rats. Although these results suggested a circadian rhythm in the function of the central 5-HT1A receptor, it was not possible to completely exclude drug disposition as the generating factor. The present study investigated circadian rhythms in the behavioral responses to intracerebroventricular administration of 8-OH-DPAT in rats. The results indicated the existence of circadian rhythms of a similar pattern to those observed in the forepaw treading and head weaving responses to s.c. administration of the drug. The flat body posture response observed following s.c. drug administration was not evident in the present study. These observations suggest that the central postsynaptic 5-HT1A receptor exhibits a circadian rhythm in its function.

Circadian rhythm in the hypothermic response to serotonin1A receptor agonist 8-OH-DPAT in rats

In a recent study, we found a circadian rhythm in the serotonin (5-HT) syndrome (forepaw treading, head weaving, and flat body posture) in the response to the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). The present study examined the rhythm in the responsiveness to 8-OH-DPAT by observing hypothermia, another index of the 5-HT1A receptor function. Rats standardized to L(1800-0600) : D(0600-1800) were subcutaneously administered with 0.16 mg/kg 8-OH-DPAT at one of the following times of day: 00:00, 04:00, 08:00, 12:00, 16:00, 20:00 h. Two parameters of assessing the hypothermic response, the maximum decrease in temperature after the administration (MAXDT) and the area under the curve of the decrease in temperature (AUCDT), displayed significant circadian rhythms with the peaks in the middark phase (12:00 h). The waveform of the rhythms observed was similar to that of the rhythms that we observed previously in the 5-HT syndrome. The evidence presented here further supports that the central postsynaptic 5-HT1A receptor function exhibits a circadian rhythm.

Circadian rhythm in the function of central 5-HT1A receptors is endogenous in nature

In a recent study, we found a circadian rhythm in the response of central serotonin (5-HT)1A receptors to 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). In the present study, the 8-OH-DPAT-induced 5-HT behavioural syndrome was examined in rats kept under continuous dark (DD) conditions for 6 days. The results revealed a circadian rhythm in the behavioural response to 8-OH-DPAT under DD conditions. The pattern of this rhythm was similar to that observed under the light-dark conditions, except for the phase delay that corresponds to the period of free-running rhythm. These results strongly suggest that the rhythm in the function of central 5-HT1A receptors is driven by the endogenous oscillator.

Multiple-scattering effects in the second-harmonic generation of light in reflection from a randomly rough metal surface

We present a rigorous numerical simulation analysis of the second-harmonic generation of p-polarized light in reflection from a one-dimensional, randomly rough, metal surface when the plane of incidence is perpendicular to the generators of the surface. When the incident light cannot couple to surface electromagnetic waves supported by the metal surface at the fundamental frequency, the angular distribution of the intensity of the incoherent component of the scattered light at the harmonic frequency displays either well-defined peaks or dips in the retroreflection direction and in the direction normal to the mean plane of the surface. These effects are suppressed by the direct excitation of surface polaritons at the fundamental frequency.

Circadian rhythm in the responsiveness of central 5-HT2A receptor to DOI in rats

The present study investigated the circadian variation in the behavioral response to the selective 5-HT2A/2C receptor agonist (+/-)-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI). Rats were subcutaneously injected with DOI at 0000, 0400, 0800, 1200, 1600, or 2000 hours. The wet-dog shake (WDS) response was counted following administration of DOI. A circadian rhythm that peaked during the late light period (0400 hours) and reached the lowest point during the late dark period (1600 hours), was observed in the DOI-induced WDS response. In a separate experiment, DOI was administered intra-cerebroventricularly at either 0400 or 1600 hours. The WDS response to the drug at 0400 hours was significantly higher than the response at 1600 hours. These results suggest that the function of the central 5-HT2A receptor exhibits a circadian rhythm.

Circadian rhythm in the response of central 5-HT1A receptors to 8-OH-DPAT in rats

Circadian rhythm in the behavioral responsiveness to the selective 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) was studied in rats. Rats were subcutaneously injected with 8-OH-DPAT at one of the following times of day: 0000, 0400, 0800, 1200, 1600, 2000 hours. The post-synaptic 5-HT1A receptor behavioral syndrome, that is, forepaw treading, head weaving, and flat body posture, were measured after the administration of 8-OH-DPAT. Circadian rhythms were found in each of the behavioral responses to 8-OH-DPAT. Peak responses were observed in the mid-dark phase (1200 hours) while the weakest responses were observed in the mid-light phase (0000 hours). In a subsequent experiment, 8-OH-DPAT was administered intracerebroventricularly during the mid-dark phase and the mid-light phase. The behavioral responses to the drug in the mid-dark phase were significantly higher than those in the mid-light phase. These results suggest that the function of central postsynaptic 5-HT1A receptor exhibits circadian rhythm.

Enhanced backscattering from a free-standing dielectric film

It has been known theoretically for a few years that not only a rough metallic surface but also a rough dielectric surface can produce an enhanced backscattering peak. Because of difficulty in the fabrication of one- or two-dimensional rough dielectric surfaces with a high index of refraction, no experiments to date have been able to reveal such a peak in scattering from a rough dielectric surface. We present experimental results showing enhanced backscattering from a free-standing dielectric film and compare them with the results of numerical simulations of such scattering. The vacuum-dielectric interface is a one-dimensional, randomly rough surface, and the dielectric-vacuum interface is approximately planar.The results of the numerical simulations of scattering from a one-dimensional, randomly rough free-standing dielectric film are in qualitative agreement with the experimental data, and it is believed that the main mechanism responsible for the enhanced backscattering peak is the reflection from the flat dielectric-vacuum interface. The coherent addition of a given light path that interacts with the rough dielectric surface at two different points because of its partial reflection from the back surface and its time-reversed partner leads to an enhancement of the intensity of scattering in the retroreflection direction with respect to the intensity of scattering in other directions.

Enhanced backscattering from a one-dimensional rough dielectric film on a glass substrate

We have observed the enhanced backscattering of light from a characterized dielectric film deposited upon a glass substrate when the light illuminates the rough surface from the vacuum. The vacuum-dielectric interface is one dimensional, randomly rough, while the dielectric-glass interface is approximately planar. Numerical and experimental studies reveal that the main mechanism responsible for the enhanced backscattering is the constructive interference between two waves that follow reciprocal scattering paths through the dielectric film, which is also strengthened by the multiple scattering from the rough vacuum-dielectric interface.

Coherence in the single and multiple scattering of light from randomly rough surfaces

One of the most interesting phenomena associated with the scattering of light from a randomly rough surface is that of enhanced backscattering. This is the presence of a well-defined peak in the retroreflection direction in the angular distribution of an incoherent component of mean scattered intensity of the light scattered from such a surface that is primarily due to the coherent interference of each multiply reflected optical path with its time-reversed partner. It is an example of a broader class of multiple-scattering phenomena that goes under the name of weak localization. Not all manifestations of weak localization in the interaction of light with a randomly rough surface are in backscattering. It was recently shown that the average diffuse intensity from randomly rough surfaces with even symmetry can be enhanced or reduced in the specular direction because of the constructive interference between correlated pairs of scatters. We present a recent theoretical analysis and experimental results that cover four kinds of enhancement: enhanced backscattering, enhanced transmission, enhanced specular, and enhanced refraction for one-dimensional and two-dimensional surfaces. These are manifestations of coherent effects that remain after ensemble averaging.

Interaction of two optical beams at a symmetric random surface

<p>Recently it was shown that the incoherent part of light scattered from random surfaces with even profiles displays a well-defined peak in the specular direction. This effect has been termed specular enhancement.</p><p>Here we present an experimental and theoretical study of the scattering of two coherent optical beams from a symmetric random surface. It is found that, in addition to the two sharp peaks corresponding to the enhancements in the specular directions, there is a third peak that is due to the interaction of the two optical beams at the surface.</p>

[Establishment of the human stomach poorly-differentiated adenocarcinoma (PdGC-81) cell line and its biological character]

The gastric cancer specimen was obtained from a female patient, 65 years old. The metastatic node in the greater omentum, demonstrated by pathology as a poorly-differentiated adenocarcinoma, was cut into small cubes (1 mm3) and cultured. The human stomach poorly-differentiated adenocarcinoma cell line (PdGC-81) was thus established. It had been transferred for 83 generations during 13 months. This cell line showed the following characters: 1. The pathological features of the tumor transplanted in mice was similar to that of the original inoculated lesion. 2. Microscopically, the majority of the cells were elliptical and polygonal epithelial cells with abnormal mitotic figures and 2-4 nucleoli. 3. Electronmicroscopically, there were rich microvilli on the surface of the cells. Desmosomes and abundant ribosomes were also observed. 4. The growth curves of the 33rd and 65th passages were determined. They multiplied 23 and 21 times within 8 days, the doubling times were 41.4 and 43.4 hours. The mitotic indexes attained their peak on day 3 in 33rd passage (80.5%) and on day 4 in 65th passage (72%). 5. The numbers of the chromosomes ranged from 56 to 60. This cell line may be considered as the subtriploid.