[Familial brain abscess as a complication of hereditary hemorrhagic telangiectasia]

The hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease) is an inherited autosomal dominant disease with angiodysplasia of the skin, mucosa, parenchymal organs, and it can affect the central nervous system. In 40% of the cases neurological complications, most frequently intracerebral abscesses occur. In this study, the case history of a patient with central nervous system manifestation of hereditary hemorrhagic telangiectasia showing familiar aggregation of brain abscess will be presented. A young male patient was admitted to Neurological Department because of his first epileptic seizure and progressive right hemispheric symptoms. His examinations showed frontal abscess, which was surgically removed. The frequent nose-bleeding of the patient and recurrent brain abscess in his brother's history provided the possibility of hereditary hemorrhagic telangiectasia. The background of brain abscess were multiple pulmonary arteriovenous malformation, which were embolized by repeated angiography. Familiar brain abscess is very rare. However, in the case of brain abscess especially with familiarity diagnosis of the Rendu-Osler-Weber disease should be considered.

Sustained L-type calcium currents in dissociated deep dorsal horn neurons of the rat: characteristics and modulation

Deep dorsal horn neurons present plateau properties involved in non-linear integration of nociceptive inputs, in the windup of the discharge, and in the expression of long-lasting afterdischarges. In vitro experiments using intracellular recordings in a slice preparation of the rat spinal cord have established that they are supported in part by voltage-dependent calcium currents, and positively modulated by metabotropic glutamate receptor activation. In the present study, whole-cell patch-clamp recordings in acutely isolated soma of dorsal horn neurons (n=48) were used to analyse the voltage-dependent calcium currents involved.Deep dorsal horn neurons expressed both inactivating and non-inactivating calcium currents with Ca(2+) or Ba(2+) used as a charge carrier. The non-inactivating component activated at intermediate threshold (-55mV), and was blocked mostly by nifedipine (61+/-6%). Although voltage-dependent facilitation of whole-cell calcium currents could be obtained by prepulses to +100mV, repetitive depolarization at potentials compatible with the plateau (-45mV and -10mV) failed to induce facilitation of calcium currents. No direct modulation of somatic calcium currents by application of (S)-3,5-dihydroxyphenylglycine, a selective group I metabotropic glutamate receptor agonist and 1S,3R-1-amino-1,3-cyclopentanedicarboxylic acid, a group I and II metabotropic glutamate receptor agonist, was found, while application of the metabotropic GABA(B) receptor agonist baclofen induced a significant decrease in calcium currents.Thus, the present voltage-clamp study shows that rat deep dorsal horn neurons express a non-inactivating, nifedipine sensitive, intermediate threshold (-55mV) calcium current which could provide the depolarizing drive to generate plateau potentials near threshold. Our results also indicate that calcium currents are not sensitized following repetitive stimulation, and not modulated by metabotropic glutamate receptor activation. They provide, however, the first evidence for a direct modulation of voltage-gated calcium channels in dorsal horn neurons by GABA(B) receptor activation, which may contribute to the mechanism of baclofen's antinociceptive activity.

Clinical value of technetium-99m-HMPAO-labeled leukocyte scintigraphy and spiral computed tomography in active Crohn's disease

OBJECTIVES

The diagnostic accuracy of technetium-99m-HMPAO-labeled leukocyte scintigraphy (LS) and spiral CT for the detection of inflammatory activity was assessed; the extent of the inflammation and the complications were compared with the clinical and laboratory parameters and with the endoscopic and radiological findings in patients with clinically active Crohn's disease (CD).

METHODS

Twenty-eight patients (13 men, 15 women, average age 32.5 yr, range: 18-59 yr) with an acute exacerbation of CD were enrolled in the study. The disease behavior type and the maximum extent of inflammation were established by means of endoscopy (jejunoscopy and colonoscopy) and enteroclysis. Nine patients with severe complications (abscess and stenosis) underwent operation. The GI tract was divided into five segments (small bowel, ascending colon, transverse colon, descending colon, and rectosigmoid), the LS, CT, endoscopic, and radiological pictures of all segments were graded (range: 0-3) and the scores were summed and compared.

RESULTS

The investigations indicated that LS and CT had sensitivities of 76.1% and 71.8%, specificities of 91.0% and 83.5%, and accuracies of 82.6% and 77.5%, respectively, for detection of segmental inflammatory activity. With regard to the disease behavior type, the sensitivities of LS and CT were, respectively, 77% and 100% in the penetrating-fistulizing, 80% and 73% in the stricturing, and 68% and 64% in the inflammatory form of CD. CT detected all abdominal abscesses, whereas the diagnostic value of LS for the detection of the complications of CD was lower. The inflammatory activity scores measured by LS displayed a closer correlation than that of CT with the Best index (r = 0.71, p < 0.0005 vs r = 0.63, p < 0.001), the van Hees index (r = 0.61, p < 0.005 vs r = 0.59, p < 0.005), the serum fibrinogen level (r = 0.67, p < 0.005 vs r = 0.59, p < 0.005), or the C-reactive protein level (r = 0.64, p < 0.005 vs r = 0.51, p < 0.01).

CONCLUSIONS

Both LS and CT are valuable noninvasive diagnostic methods in cases involving severe, active CD. LS seemed better for the detection of segmental inflammatory activity, whereas CT displayed excellent suitability for the recognition of complications: abdominal abscesses were diagnosed with 100% efficiency.

[Multidisciplinary therapy of colorectal cancer]

A multidisciplinary program for the treatment of colorectal cancer is described. The main objective of the authors has been to define uniform up to date guidelines based on recent progress in the treatment of colorectal cancer. Preoperative diagnostic procedures are summarized which advance determination of clinical stage and prognosis. These information essentially determine care. Sequences of surgical methods, preoperative and postoperative radiotherapy and medical treatments are discussed according to tumor stages. Guidelines for surveillance following active treatment and recommendation for the screening of population at high risk for colorectal cancer are presented.

Intracellular trafficking of photoreceptors during light-induced signal transduction in plants

Plants monitor changes in the ambient light environment by highly specialised photoreceptors, which include the red/far-red photoreversible phytochromes, the blue-light-absorbing cryptochromes and phototropin and the so-far-unidentified UVB photoreceptor(s). Light easily penetrates plant organs/tissues and reaches even the subcellular compartments of various cell types. Therefore, it is not surprising that the determination of the intracellular localisation of photoreceptors has been, for many years, a major, and often controversial, subject of plant photobiology and cell biology research. Phototropin, one of the blue-light photoreceptors of higher plants, controls phototropism by monitoring the direction of light, and it is localised in or at the plasmalemma. In contrast, the subcellular localisation of phytochromes changes dynamically and exhibits a very complex pattern. These photoreceptors are localised in the cytosol in dark- grown tissues. Irradiation, however, induces import of phytochromes into the nucleus. The import occurs in a light-quality- and light-quantity-dependent fashion and, as such, seems to be unique to higher plants. Light-induced accumulation of phytochromes in the nuclei correlates well with various physiological responses mediated by these photoreceptors. These observations indicate that light-dependent intracellular redistribution of phytochrome photoreceptors is one of the major regulatory steps in photomorphogenesis.

Nucleo-cytoplasmic partitioning of the plant photoreceptors phytochromes

Phytochromes in harmony with blue light photoreceptors play a major role in controlling plant growth and development from germination to seed maturation. Light absorption by phytochromes triggers a signaling cascade, phototransduction, which culminates in regulated gene expression. A major regulatory step at the cellular level, which affects specificities of light-induced physiological responses, seems to be the light-quality and light-quantity dependent nuclear import of the phytochromes themselves. The correlations found between the nuclear import of phytochromes (phyA and phyB) and various physiological responses regulated by these photoreceptors provides strong support for this hypothesis.

Control of nuclear import and phytochromes

The past year has brought significant changes in our understanding of the molecular mechanism of photoreceptor-regulated gene expression in higher plants. The light-quantity- and light-quality-dependent nuclear import of phytochromes, followed by the conformation-dependent direct interaction of these phytochromes with transcription factors, seems to play a major role in light-modulated plant growth and development.

Water enema CT examination of rectum cancer by reduced amount of water

OBJECTIVE

To define whether volume of water, administered during water enema CT (WE-CT) for local staging of rectal cancer, may be reduced without compromising the diagnostic value of the examination.

MATERIALS AND METHODS

29 patients with rectum cancer underwent preoperative WE-CT. Contrast-enhanced CT (equilibrium phase) measurements were performed after i.v. injection of smooth muscle relaxant and rectal administration of 400-500 ml lukewarm tap water. Quality of the obtained scans was evaluated and the images were analyzed for depth of tumor invasion. Results of the CT examinations were compared to findings at surgery.

RESULTS

Despite reduced dose of water enema, 19/29 examinations were of excellent quality, 6/29 good, and 4/29 poor, but still diagnostic. We achieved sensitivity (90.1), specificity (70.1) and accuracy (86.2) in differentiating tumors confined to the bowel wall from those extending beyond it.

CONCLUSION

Large volume of water enema administered during CT examination of the rectum may cause complaints and increases the risk of complications. Our results prove that using lower amount of water does not impair the quality of examination and accuracy of local staging of rectum carcinomas.

Plateau potential-dependent windup of the response to primary afferent stimuli in rat dorsal horn neurons

In the spinal cord, repetitive stimulation of nociceptive afferent fibres induces a progressive build-up of dorsal horn neuron (DHN) responses. This 'action potential windup' is used as a cellular model of central sensitization to pain. It partly relies on synaptic plasticity, being reduced after blocking NMDA and neurokinin receptors. Using intracellular recordings in a slice preparation of the rat spinal cord, we have analysed the implication of an additional non-synaptic component of windup. Primary afferent fibres were electrically stimulated in the dorsal root. Of 47 responding deep DHNs, 17 (36%) produced action potential windup and afterdischarge during consecutive periods of repeated stimuli (0.4-1 Hz) activating high- (n = 13 neurons) and low-threshold (n = 6 neurons) afferent fibres. When the NMDA receptors were blocked, the rate of windup did not change. In all neurons, there was an absolute correlation between expression of windup and the production of calcium-dependent plateau potentials. Sensitization of the DHN response, similar to the synaptically induced windup, was obtained by repetitive intracellular injection of depolarizing current pulses. This intracellularly induced windup had the same pharmacology as the plateau potential. Synaptically induced windup was also abolished by nifedipine, an L-type calcium-channel blocker. Expression of plateau properties in DHNs is therefore a critical component of windup, operating downstream of synaptic processes. Being associated with calcium influx, generation of plateau potentials could be a link between short-term plasticity and the long-term modification of DHN excitability associated with central sensitization.

Receptor subtypes mediating depressor responses to microinjections of nicotine into medial NTS of the rat

Microinjections (50 nl) of nicotine (0.01-10 microM) into the nucleus of the solitary tract (NTS) of adult, urethan-anesthetized, artificially ventilated, male Wistar rats, elicited decreases in blood pressure and heart rate. Prior microinjections of alpha-bungarotoxin (alpha-BT) and alpha-conotoxin ImI (specific toxins for nicotinic receptors containing alpha7 subunits) elicited a 20-38% reduction in nicotine responses. Similarly, prior microinjections of hexamethonium, mecamylamine, and alpha-conotoxin AuIB (specific blockers or toxin for nicotinic receptors containing alpha3beta4 subunits) elicited a 47-79% reduction in nicotine responses. Nicotine responses were completely blocked by prior sequential microinjections of alpha-BT and mecamylamine into the NTS. Complete blockade of excitatory amino acid receptors (EAARs) in the NTS did not attenuate the responses to nicotine. It was concluded that 1) the predominant type of nicotinic receptor in the NTS contains alpha3beta4 subunits, 2) a smaller proportion contains alpha7 subunits, 3) the presynaptic nicotinic receptors in the NTS do not contribute to nicotine-induced responses, and 4) EAARs in the NTS are not involved in mediating responses to nicotine.

UV-B radiation induced exchange of the D1 reaction centre subunits produced from the psbA2 and psbA3 genes in the Cyanobacterium synechocystis sp. PCC 6803

UV-B irradiation of Synechocystis 6803 cells inhibits photosystem II activity, which can be restored via de novo synthesis of the D1 (and D2) reaction center subunits. Recently we have shown that of the two psbA genes that encode identical D1 proteins in Synechocystis 6803, UV-B preferentially enhances the transcription of psbA3 compared to that of psbA2 [Máté, Z., Sass, L., Szekeres, M., Vass, I. and Nagy, F. (1998) J. Biol. Chem. 273, 17439-17444]. Here we studied the effect of UV-B on the synthesis of the D1 protein from the psbA2 and psbA3 genes in the P7 mutant of Synechocystis 6803. In this mutant, psbA2 carries the Ala251-->Val point mutation, which confers resistance to the photosystem II electron transport inhibitor metribuzin, but psbA3 is the same as in the wild-type. By applying variable chlorophyll fluorescence measurements to distinguish between metribuzin-sensitive and metribuzin-resistant photosystem II centers we quantified the amount of the D1 protein produced from each of the psbA3 and psbA2 genes. When the cells were exposed to UV-B light, the fraction of D1 protein produced from the psbA3 gene was increased from 15-20 to 32-40% of the total D1. This effect was reversible by transferring the cells to visible light. The rate of D1 production from psbA3 increased with increasing UV-B intensities, and was a transient phenomenon at low UV-B levels (0.1 microE x m-2 x s-1). It is concluded that the enhancement of psbA3 gene transcription by UV-B light leads to enhanced D1 protein synthesis from this gene. Our findings demonstrate that the main role of psbA3 transcription activated by UV-B is to increase the size of the psbA mRNA pool available for translation when a rapid repair of the D1 protein is needed under UV-B stress.

Photocontrol of subcellular partitioning of phytochrome-B:GFP fusion protein in tobacco seedlings

Photomorphogenesis of higher plants is regulated by photoreceptors including the red/far-red light-absorbing phytochromes, blue-UV/A sensing cryptochromes and as yet uncharacterized UV/B receptors. Specific phototransduction pathways that are controlled by either individual or interacting photoreceptors mediate regulation. Phytochrome B (phyB) is the major red light-sensing photoreceptor. Phototransduction mediated by this light sensor has been shown to include light-dependent nuclear import and interaction of phyB with transcription factor-like proteins in the nucleus. Here we report that nuclear import of phyB and physiological responses regulated by this photoreceptor exhibit very similar wavelength- and fluence rate-dependence. Nuclear import of phyB is insensitive to single red, blue and far-red light pulses. It is induced by continuous red light and to a lesser extent by continuous blue light, whereas far-red light is completely ineffective. The data presented indicate that light-dependent partitioning of phyB exhibits features characteristic of blue light responsiveness amplification, a phenomenon that is thought to be mediated by interaction of phyB with CRY1.

Light-induced nuclear import of phytochrome-A:GFP fusion proteins is differentially regulated in transgenic tobacco and Arabidopsis

Phytochromes (phy) are a family of photoreceptors that control various aspects of light-dependent plant development. Phytochrome A (phyA) is responsible for the very low fluence response (VLFR) under inductive light conditions and for the high irradiance response (HIR) under continuous far-red light. We have recently shown that nuclear import of rice phyA:GFP is regulated by VLFR in transgenic tobacco. The import is preceded by very fast, light-induced formation of sequestered areas of phyA:GFP in the cytosol. Here we report that expression of the Arabidopsis phyA:GFP fusion protein in phyA-deficient Arabidopsis plants complements the mutant phenotype. In these transgenic Arabidopsis lines, both light-dependent cytosolic formation of sequestered areas of the phyA:GFP as well as VLFR or HIR-mediated nuclear import of the fusion protein was observed. By contrast, light-dependent nuclear import of the same fusion protein was induced only by continuous far-red light (HIR) but not by pulses of far-red light (VLFR) in transgenic tobacco. These results demonstrate that photoregulation of intracellular partitioning of the Arabidopsis phyA:GFP differs significantly in different genetic backgrounds.

[Total mesorectal excision with ultrasonic coagulation knife ("UltraCision") in surgery of rectal cancer]

The authors report a total of 62 middle and low third rectal cancer cases operated on by total mesorectal excision by the method of Heald. The oncological basis of this procedure is the horizontal regional metastatization of rectal cancer. The total mesorectal excision facilitates, the low anterior resections and preservation of sphincter with an ultra-low colorectal, or coloanal anastomosis using the double stapling technique. In the authors' experience, the "UltraCision" cutting-coagulating device permits an atraumatic, bloodless and oncologically correct dissection. Using the double stapling technique, we succeeded in 60% of our middle- and low-third rectal cancer patients to perform a sphincter preserving low anterior resection. In 9 (28%) of the low third rectal cancer patients, preservation of the sphincter was possible with oncologically correct anterior resection and an ultra-low colo-anal anastomosis. Three anastomotic insufficiencies occurred, two of them healed on lotion-suction drainage, and one on the application of transient protective ileostomy. The literature data suggest a lower local recurrency rate after radical rectal cancer surgery, if total mesorectal excision is performed.

Intracranial EEG versus flumazenil and glucose PET in children with extratemporal lobe epilepsy

OBJECTIVE

To compare abnormalities determined in 2-deoxy-2-[18F]fluoro-D-glucose (FDG) and [11C]flumazenil (FMZ) PET images with intracranial EEG data in patients with extratemporal lobe epilepsy.

BACKGROUND

Although PET studies with FDG and FMZ are being used clinically to localize epileptogenic regions in patients with refractory epilepsy, the electrophysiologic significance of the identified PET abnormalities remains poorly understood.

METHODS

We studied 10 patients, mostly children (4 boys, 6 girls, aged 2 to 19 years; mean age, 11 years), who underwent FDG and FMZ PET scans, intracranial EEG monitoring, and cortical resection for intractable epilepsy. EEG electrode positions relative to the brain surface were determined from MRI image volumes. Cortical areas of abnormal glucose metabolism or FMZ binding were determined objectively based on asymmetry measures derived from homotopic cortical areas at three asymmetry thresholds. PET data were then coregistered with the MRI and overlaid on the MRI surface. A receiver operating characteristics (ROC) analysis was performed to determine the specificity and sensitivity of PET-defined abnormalities against the gold standard of intracranial EEG data.

RESULTS

FMZ PET detected at least part of the seizure onset zone in all subjects, whereas FDG PET failed to detect the seizure onset region in two of 10 patients. The area under the ROC curves was higher for FMZ than FDG PET for both seizure onset (p = 0.01) and frequent interictal spiking (p = 0.04). Both FMZ and FDG PET showed poor performance for detection of rapid seizure spread (area under the ROC curve not significantly different from 0.5).

CONCLUSIONS

[11C]flumazenil (FMZ) PET is significantly more sensitive than 2-deoxy-2-[18F]fluoro-D-glucose (FDG) PET for the detection of cortical regions of seizure onset and frequent spiking in patients with extratemporal lobe epilepsy, whereas both FDG and FMZ PET show low sensitivity in the detection of cortical areas of rapid seizure spread. The application of PET, in particular FMZ PET, in guiding subdural electrode placement in refractory extratemporal lobe epilepsy will enhance coverage of the epileptogenic zone.

UV-B induced differential transcription of psbD genes encoding the D2 protein of Photosystem II in the cyanobacterium Synechocystis 6803

UV-B irradiation of intact Synechocystis sp. PCC 6803 cells results in the loss of Photosystem II activity, which can be repaired via de novo synthesis of the D1 and D2 reaction center subunits. A key step in the repair process is the differential transcription of the psbA2 and psbA3 genes, coding for identical D1 polypeptides [Máté et al. (1998) J Biol Chem 273: 17439-17444]. In the present work, we investigated for the first time the effect of UV-B irradiation on the transcription of the psbD1 and psbD2 genes encoding identical D2 polypeptides. By using gene-specific S1 nuclease protection assay we showed differential UV-B induced transcription of the two psbD genes: the level of psbD1 mRNA was increased 1.5-2 fold, whereas the accumulation of psbD2 mRNA was 5-7 fold. The induction of psbD2 transcript accumulation by low intensity light was specific for the UV-B range. UV-A emission from the applied UV source, as well as 100 muE m(-2) s(-1) white light had negligible effect. Increase in the psbD2 mRNA level was observed at very low UV-B intensities, which did not cause damage to the function and protein structure of PS II. Expression patterns of chimeric genes containing the promoter regions of the psbD1, psbD2 genes fused to the firefly luciferase (luc) reporter gene showed similar induction as observed for the endogenous psbD genes. Our findings demonstrate that UV-B radiation induces differential expression of the of the psbD1 and psbD2 genes. We propose that the primarily expressed psbD2 serves as a UV stress gene and participates in a rapid defense response against UV-B stress. This effect is regulated, at least partially, at the level of transcription.

Short- and long-term redox regulation of photosynthetic light energy distribution and photosystem stoichiometry by acetate metabolism in the green alga, Chlamydobotrys stellata

The effect of acetate metabolism on the light energy distribution between the two photosystems, on the PS II/PS I stoichiometry and on the expression of psbA and psbB and psaA genes was investigated in the green alga, Chlamydobotrys stellata during autotrophic (CO(2)), mixotrophic (CO(2) plus acetate) and photoheterotrophic (only acetate) cultivation. It was observed that acetate assimilation in the glyoxylate cycle resulted in a large drop in the ATP content and a concomitant increase in the NADPH content of the cells. The combined effect of high NADPH concentration and linear electron transport brought about an over-reduction of the inter-photosystem electron transport components. The reduced state of the inter-photosystem components initiated a state 1/state 2 transition of LHC II and a decrease in the PS II/PS I ratio. The PS II/ PS I ratio was reduced because the synthesis of PS II reaction centers was repressed and that of the PS I reaction centers was slightly enhanced by acetate cultivation. The amount of PsbA and PsbB proteins of PS II and the abundance of psbA mRNA decreased. The abundance of PS I PsaA protein and psaAmRNA were only slightly increased. All of the acetate-induced effects were reversible when the cells were transferred back to an acetate-free medium. Our observations demonstrate that the expression of the PS II psbA and psbB and PS I psaA genes is regulated by the redox state of the inter-photosystem components at the transcriptional level. Experiments carried out in the presence of DBMIB which facilitates the reduction of plastoquinone pool indicate that the expression of genes encoding the components of PS II and PS I are controlled by the redox state of a component (cytochrome b/f complex) located behind the plastoquinone pool.

Glucose and [11C]flumazenil positron emission tomography abnormalities of thalamic nuclei in temporal lobe epilepsy

OBJECTIVES

To analyze interictal patterns of thalamic nuclei glucose metabolism and benzodiazepine receptor binding in patients with medically intractable temporal lobe epilepsy (TLE) using high-resolution 2-deoxy-2-[18F]fluoro-D-glucose (FDG) and [11C]flumazenil (FMZ) PET.

BACKGROUND

Structural and glucose metabolic abnormalities of the thalamus are considered important in the pathophysiology of TLE. The differential involvement of various thalamic nuclei in humans is not known.

METHODS

Twelve patients with TLE underwent volumetric MRI, FDG and FMZ PET, and prolonged video-EEG monitoring. Normalized values and asymmetries of glucose metabolism and FMZ binding were obtained in three thalamic regions (dorsomedial nucleus [DMN], pulvinar, and lateral thalamus [LAT]) defined on MRI and copied to coregistered, partial-volume-corrected FDG and FMZ PET images. Hippocampal and amygdaloid FMZ binding asymmetries and thalamic volumes also were measured.

RESULTS

The DMN showed significantly lower glucose metabolism and FMZ binding on the side of the epileptic focus. The LAT showed bilateral hypermetabolism and increased FMZ binding. There was a significant correlation between the FMZ binding asymmetries of the DMN and amygdala. The PET abnormalities were associated with a significant volume loss of the thalamus ipsilateral to the seizure focus.

CONCLUSIONS

Decreased [11C]flumazenil (FMZ) binding and glucose metabolism of the dorsomedial nucleus (DMN) are common and have strong lateralization value for the seizure focus in human temporal lobe epilepsy. Decreased benzodiazepine receptor binding can be due to neuronal loss, as suggested by volume loss, but also may indicate impaired gamma-aminobutyric acid (GABA)ergic transmission in the DMN, which has strong reciprocal connections with other parts of the limbic system. Increased glucose metabolism and FMZ binding in the lateral thalamus could represent an upregulation of GABA-mediated inhibitory circuits.

The circadian clock controls the expression pattern of the circadian input photoreceptor, phytochrome B

Developmental and physiological responses are regulated by light throughout the entire life cycle of higher plants. To sense changes in the light environment, plants have developed various photoreceptors, including the red/far-red light-absorbing phytochromes and blue light-absorbing cryptochromes. A wide variety of physiological responses, including most light responses, also are modulated by circadian rhythms that are generated by an endogenous oscillator, the circadian clock. To provide information on local time, circadian clocks are synchronized and entrained by environmental time cues, of which light is among the most important. Light-driven entrainment of the Arabidopsis circadian clock has been shown to be mediated by phytochrome A (phyA), phytochrome B (phyB), and cryptochromes 1 and 2, thus affirming the roles of these photoreceptors as input regulators to the plant circadian clock. Here we show that the expression of PHYB::LUC reporter genes containing the promoter and 5' untranslated region of the tobacco NtPHYB1 or Arabidopsis AtPHYB genes fused to the luciferase (LUC) gene exhibit robust circadian oscillations in transgenic plants. We demonstrate that the abundance of PHYB RNA retains this circadian regulation and use a PHYB::Luc fusion protein to show that the rate of PHYB synthesis is also rhythmic. The abundance of bulk PHYB protein, however, exhibits only weak circadian rhythmicity, if any. These data suggest that photoreceptor gene expression patterns may be significant in the daily regulation of plant physiology and indicate an unexpectedly intimate relationship between the components of the input pathway and the putative circadian clock mechanism in higher plants.

Headache in intracranial tumors

The clinical data of 279 consecutive patients with brain tumors were analyzed pre- and postoperatively in the period of 1994-95. No headache had been recorded in the history of 115 patients, neither pre- nor postoperatively. Only in 139 of the remaining 164 headache patients was there a probable connection between headache and intracranial neoplasm. In the headache group the most frequent findings were metastatic brain tumors and different astrocytomas. Hypophysis adenomas and glioblastoma multiforme were frequent in the no-headache group. Progressive headache was found in 110 patients (67% of the headache group). The progressive character of the headache showed a close relationship with the prevailing edema, but not with the size of the tumor. Infratentorial and intraventricular tumors were more frequently accompanied by headache than those located supratentorially, probably due to the disturbance of CSF circulation and midline dislocation with increased intracranial pressure. Only in one-third of the patients did the site of the tumor coincide with the lateralization of headache. In half of the headache patients, pain was the first complaint. Headaches caused by tumor were characterized by pain lasting for hours, developing for weeks or months. The headache was never permanent and there was no regular daily recurrence.

[Abdominal actinomycosis presenting as a malignant tumor--report of a case and review of the literature]

Actinomyces israelii is a normal inhabitant in the gastrointestinal tract of humans, it rarely causes disease. Abdominal involvement occurs in only 20 percent of all cases and can mimic malignant diseases, tuberculosis and inflammatory bowel disease. A case of a 36 years old female patient with abdominal actinomycosis and review of the literature is reported. Symptoms was presented as an acute abdomen associated with painful epigastric and left subcostal mass. The pathologic process infiltrated the retroperitoneal space simulated sarcoma or lymphoma. Diagnosis was established only at the second laparotomy, when histologic examination of the removed lymph node disclosed actinomycosis. The patient is completely free of symptoms 6 month after the second operation.