Sympatric divergence and clinal variation in multiple coloration traits of Ficedula flycatchers.

Geographic variation in phenotypes plays a key role in fundamental evolutionary processes such as local adaptation, population differentiation and speciation, but the selective forces behind it are rarely known. We found support for the hypothesis that geographic variation in plumage traits of the pied flycatcher Ficedula hypoleuca is explained by character displacement with the collared flycatcher Ficedula albicollis in the contact zone. The plumage traits of the pied flycatcher differed strongly from the more conspicuous collared flycatcher in a sympatric area but increased in conspicuousness with increasing distance to there. Phenotypic differentiation (PST ) was higher than that in neutral genetic markers (FST ), and the effect of geographic distance remained when statistically controlling for neutral genetic differentiation. This suggests that a cline created by character displacement and gene flow explains phenotypic variation across the distribution of this species. The different plumage traits of the pied flycatcher are strongly to moderately correlated, indicating that they evolve non-independently from each other. The flycatchers provide an example of plumage patterns diverging in two species that differ in several aspects of appearance. The divergence in sympatry and convergence in allopatry in these birds provide a possibility to study the evolutionary mechanisms behind the highly divergent avian plumage patterns.

Molecular-beam epitaxy-grown Si whisker structures: morphological, optical and electrical properties.

Scanning electron microscopy, spectroscopic ellipsometry, and current-voltage and current-temperature measurements were employed to characterize nanowhisker structures grown by molecular-beam epitaxy on Si(111) substrates. Small clusters of gold deposited on the Si surface were used as the seeds for nanowhisker growth. The diameter of grown nanowhiskers and their length ranged from 70 to 200 nm and from 580 to 890 nm, respectively. The whiskers were found to inherit the (111) orientation of the Si substrate. By means of spectroscopic ellipsometry in the range 1.5-4.77 eV, lateral optical inhomogeneity of the nanowhisker layer was revealed, with optical properties of the layer substantially differing from those of single-crystal Si. Electrical measurements point to the presence of a Schottky barrier with height 0.70 eV in the structure and to the presence of electrically active centers non-uniformly distributed over the nanowhisker length.

Nucleic Acid Structure Investigated by UV Resonance Raman Spectroscopy: Protonation Effects and A-Tract Structure.

Abstract UV resonance Raman (UVRR) spectroscopy has been used to investigate the three purine bases, adenine, guanine and inosine, as a function of pH. Excitation wavelengths of 260 and 210 nm were used to probe the in-plane ring stretching frequencies and the exocyclic functional groups, respectively. These studies are suggestive that tautomeric forms can be stabilized at low and high pH values and these forms can be identified using UVRR spectroscopy. At pH values ≤5.0, a band at 1693 cm (-1) is observed in the UVRR spectra of dAMP, which is suggestive of the imino protonated tautomer. At pH values of 10.0 and above both dGMP and IMP show evidence for forming the enolate tautomer, by the loss in intensity of the C=O stretching mode at 1686 cm(-1). The protonated forms of dGMP and dAMP exhibit distinct Raman bands at approximately 1460 and 1561 cm(-1) and we suggest that these protonated states can be identified using UVRR spectroscopy. Most distinctively, the -NH(2) scissors mode of dGMP and dAMP shifts up in frequency and increases in intensity as the pH is decreased. Interestingly, these features are also observed in a comparison of an A-tract containing dodecamer with a non A-tract dodecamer. In particular, a frequency upshift of the -NH(2) scissors mode and a mode at 1466 cm(-1) is observed. Because of the resonance enhancement and the similarities to the protonated dAMP spectrum, these features are attributed to the dA residues in the A-tract. It is suggested that these spectral features may be characteristic of 'bent' DNA.

Sugar/osmoticum levels modulate differential abscisic acid-independent expression of two stress-responsive sucrose synthase genes in Arabidopsis.

Sucrose synthase (Sus) is a key enzyme of sucrose metabolism. Two Sus-encoding genes (Sus1 and Sus2) from Arabidopsis thaliana were found to be profoundly and differentially regulated in leaves exposed to environmental stresses (cold stress, drought or O(2) deficiency). Transcript levels of Sus1 increased on exposure to cold and drought, whereas Sus2 mRNA was induced specifically by O(2) deficiency. Both cold and drought exposures induced the accumulation of soluble sugars and caused a decrease in leaf osmotic potential, whereas O(2) deficiency was characterized by a nearly complete depletion in sugars. Feeding abscisic acid (ABA) to detached leaves or subjecting Arabidopsis ABA-deficient mutants to cold stress conditions had no effect on the expression profiles of Sus1 or Sus2, whereas feeding metabolizable sugars (sucrose or glucose) or non-metabolizable osmotica [poly(ethylene glycol), sorbitol or mannitol] mimicked the effects of osmotic stress on Sus1 expression in detached leaves. By using various sucrose/mannitol solutions, we demonstrated that Sus1 was up-regulated by a decrease in leaf osmotic potential rather than an increase in sucrose concentration itself. We suggest that Sus1 expression is regulated via an ABA-independent signal transduction pathway that is related to the perception of a decrease in leaf osmotic potential during stresses. In contrast, the expression of Sus2 was independent of sugar/osmoticum effects, suggesting the involvement of a signal transduction mechanism distinct from that regulating Sus1 expression. The differential stress-responsive regulation of Sus genes in leaves might represent part of a general cellular response to the allocation of carbohydrates during acclimation processes.

Molecular cloning and spatial expression of an ApL1 cDNA for the large subunit of ADP-glucose pyrophosphorylase from Arabidopsis thaliana.

A cDNA, ApL1a, corresponding to a homologue of the large subunit of ADP-glucose pyrophosphorylase (AGPase), has been isolated/characterised by screening a cDNA library prepared from leaves of Arabidopsis thaliana, followed by rapid amplification of cDNA 3'-ends (3'-RACE). Within the 1685 nucleotide-long sequence (excluding polyA tail), an open reading frame encodes a protein of 522 amino acids (aa), with a calculated molecular weight of 57.7 kDa. The derived aa sequence does not contain any discernible transit peptide cleavage site motif, similarly to two other recently sequenced full-length Arabidopsis homologues for AGPase, and shows ca. 58-78% identity to homologous proteins from other plants/tissues. The corresponding gene was found to be expressed in all tissues examined (rosette and stem leaves, stems, flowers and fruits). The ubiquitous expression of the gene is consistent with its critical role in starch synthesis in Arabidopsis.

Sugars and light/dark exposure trigger differential regulation of ADP-glucose pyrophosphorylase genes in Arabidopsis thaliana (thale cress).

Expression of four Arabidopsis (thale cress) genes corresponding to the small (ApS) and large subunits (ApL1, ApL2, ApL3) of ADP-glucose pyrophosphorylase (AGPase), a key enzyme of starch biosynthesis, was found to be profoundly and differentially regulated by sugar and light/dark exposures. Transcript levels of both ApL2 and ApL3, and to a lesser extent ApS, increased severalfold upon feeding sucrose or glucose to the detached leaves in the dark, whereas the mRNA content for ApL1 decreased under the same conditions. Glucose was, in general, less effective than sucrose in inducing regulation of AGPase genes, possibly due to observed limitations in its uptake when compared with sucrose uptake by detached leaves. Osmotic agents [sorbitol, poly(ethylene glycol)] had no effect on ApS, ApL2 and ApL3 transcript level, but they did mimic the effect of sucrose on ApL1 gene, suggesting that the latter is regulated by osmotic pressure rather than any particular sugar. For all the genes the sugar effect was closely mimicked by an exposure of the dark-pre-adapted leaves to the light. Under both dark and light conditions, sucrose fed to the detached leaves was found to be rapidly metabolized to hexoses and, to some extent, starch. Starch production reflected most probably an increase in substrate availability for AGPase reaction rather than being due to changes in AGPase protein content, since both the sugar feeding and light exposure had little or no effect on the activity of AGPase or on the levels of its small and large subunit proteins in leaf extracts. The data suggest tight translational or post-translational control, but they may also reflect spatial control of AGPase gene expression within a leaf. The sugar/light-dependent regulation of AGPase gene expression may represent a part of a general cellular response to the availability/allocation of carbohydrates during photosynthesis.

[Immediate, early and late results of endoscopic papillosphincterotomy]. / Neposredstvennye, blizhaisie i otdalennye rezul'taty éndoskopicheskoi papillosfinkterotomii.

Clinico-instrumental examination of 226 patients showed that there were no fatal outcomes directly after endoscopic papillosphincterotomy, the number of complications was approximately the same as after transduodenal operations on the major duodenal papilla but they took a much easier course. The high effectiveness of an endoscopic operation was confirmed in the immediate postoperative period (absence of biliary hypertension, jaundice, pancreatitis, cholangitis). In the late-term periods after EPST restenosis was rarely encountered (3.9%); duodeno-biliary reflux caused no serious disorders, while the functional activity of the sphincter Oddi which had been operated on was partly maintained in 84.2% of patients.

[Levels of gastrin and somatostatin in blood and gastroduodenal gastrin and somatostatin cells in the differentiation of treatment of patients with duodenal ulcer]. / Urovni gastrina i somatostatina v krovi, gastroduodenal'nye gastrinovye i somatostatinovye kletki pri differentsirovannom lechenii bol'nykh iazvennoi bolezn'iu dvenadtsatiperstnoi kishki.

Radioimmunoassay and immunomorphological methods were used in the study of pepsinogen 1, basal and food-stimulated gastrin and somatostatin blood levels, the number of gastroduodenal G- and D-cells as well as gastric secretion during routine-dose treatment with gastrozepin and ranisan of 45 gastroduodenal ulcer patients versus 15 controls. The patients were divided into 2 types according to blood gastrin levels and the number of pyloric G-cells: with hypergastrinemia and/or hyperplasia of the G-cells, with normogastrinemia and normal number of G-cells. A course treatment with gastrozepin of type 1 patients brought about normalization of serum gastrin and the number of the G-cells with elevation of blood somatostatin levels. In patients of type 2 the above parameters did not change. The same picture in them remained after ranisan treatment, though they developed hypergastrinemia. In patients of type 1 after ranisan treatment the above parameters did not change. The data obtained demonstrate once more heterogeneity of duodenal ulcer.

[Tactics of management of patients with stomach deformities]. / Taktika vedeniia bol'nykh s deformatsiiami zheludka.

Analysis of gastroscopy in 8781 patients revealed the deformities of the stomach in 1249 (14.2%) patients. Patients younger than 30 had a kink of the stomach and exogastric deformity in 75.5 and 17.7%, respectively. In patients who were older than 70 the respective values were 52.2 and 46.4%. The cause of gastric deformities was stated in 65% of cases (the diseases and specific forms of the adjacent organs). Computed tomography helped to reveal the cause of the deformity in 54% of the cases and ultrasonic investigation in 26% of the cases. The informative value of the used combination of computed tomography and esophagogastroduodenoscopy comprised 75%.

[The diagnosis of cancer of the stomach and large intestine under active dispensary observation]. / Diagnostika raka zheludka i tolstoi kishki v usloviiakh aktivnogo dispansernogo nabliudeniia.

Among patients placed under permanent medical observation carried out for 6-8 years, gastric carcinoma (GC) was revealed in 288 and colonic carcinoma (CC) in 377 cases. In 67 and 60% of the patients, respectively, the diagnosis was established as a result of systematic dispensary examinations. The first and second stage disease was identified in 50 and 43% of the cases, including 67% of GC and 62% of CC patients undergoing active examinations. In 40% of the cases on the average, the disease may run an asymptomatic course, including the late stages of the disease. In half the patients, the clinical manifestations did not last more than 3 months, with their duration being independent of the disease stage. It is assumed that at the initial stage the tumor may, during a short period of time, reach the size corresponding to both early and late stages of the disease, after which the rate of tumor growth is likely to be slower. The authors document the necessity of a comprehensive approach to the diagnosis of GC and CC, using the whole armamentarium of classical and up-to-date methods.

[Possibilities of laparoscopic decompression of the gallbladder in middle-aged and elderly patients with diseases of the biliary tract]. / Vozmozhnosti laparoskopicheskoi dekompressii zhelchnogo puzyria u bol'nykh pozhilogo i starcheskogo vozrasta s zabolevaniiami biliarnogo trakta.

It is established that laparoscopic cholecystostomy presents the most acceptable method of gall bladder decompression in acute cholecystitis patients of advanced age comprising a high-risk group for surgery. Cholecystostomy efficiency reaches 97.2%. In case the procedure is not feasible in acute cholecystitis patients with intrahepatic position of the gall bladder or perivesicular adhesions the preference should be given to transhepatic drainage of the gall bladder whose effectiveness is 88.5%. An expedient method of laparoscopic decompression of the biliary tracts in mechanical jaundice due to tumor obstruction of the terminal part of the common bile duct is the formation of an external biliary fistula and "continuous" direct drainage of the gall bladder warranting satisfactory results in 93.3 and 100% of cases, respectively. Patients with a 1.5-week history of mechanical jaundice are not recommended transhepatic drainage, in longer duration of the jaundice (more than 1 month) it becomes contraindicated.

[The treatment of erosive-ulcerative lesions of the upper gastrointestinal tract at a polyclinic]. / Lechenie érozivno-iazvennykh porazhenii verkhnikh otdelov zheludochno-kishechnogo trakta v usloviiakh polikliniki.

The data obtained demonstrate the efficacy of the local and oral use of antioxidant dibunol in the treatment of ulcerous lesions of the upper alimentary tract. Besides, dibunol can be used for preventing disease exacerbations. Unlike dibunol, low-energy laser radiation makes it possible to shorten the time of ulcer healing which is particularly manifest in ulcers of the body of the stomach and duodenal ulcers 0.5--0.6 cm in diameter. The times of counteracting the painful and dyspeptic syndromes using dibunol and laser radiation did not differ appreciably. Both the treatment modalities can successfully be applied under outpatient conditions.

Misoprostol and dalargin for the inpatient treatment of duodenal ulcer in the USSR.

In the USSR, uncomplicated duodenal ulcer is usually managed in an inpatient setting. A double-blind, randomized, double-dummy, multiclinic, comparative trial examined the safety and efficacy of oral misoprostol (200 micrograms qid) and intramuscular dalargin (1 mg bid) in duodenal ulcer healing. Dalargin, an enkephalin peptide with gastric antisecretory and cytoprotective properties, is commonly used in the USSR for treating peptic ulcer. The trial characteristics and monitoring were performed in accordance with US standards. Consenting patients of either sex, aged 18 to 70 years, who had a duodenal ulcer of 0.3 to 2.5 cm in diameter were enrolled. Endoscopy, physical examination, and laboratory assessments were performed on entry and after 4 weeks of treatment. The effects of the treatments on complete ulcer healing, dyspeptic symptoms, antacid consumption, adverse drug reactions, and safety were determined. Both treatment groups were well matched for demographic characteristics. The majority of patients were smokers and alcohol users and had a history of recurrent peptic ulcers. Misoprostol was significantly more effective than dalargin in inducing duodenal ulcer healing, both in the intent-to-treat cohort (P = .001) and in the evaluable cohort (P = .0001). Both regimens were well tolerated, and no patients were withdrawn from the study because of adverse reactions. Mild, self-limiting diarrhea was reported more frequently in patients receiving misoprotol (9.4% incidence) than those receiving dalargin (1.9%). The disparity in ulcer healing between the two groups suggests that hospitalization alone is not an optimum treatment in this high-risk patient population.

[The dynamics of the focal changes in the gastric mucosa of patients with chronic gastritis based on the data from a multiyear endoscopic observation in a polyclinic]. / Dinamika ochagovykh izmenenii slizistoi obolochki zheludka u bol'nykh khronicheskim gastritom po dannym mnogoletnego éndoskopicheskogo nabliudeniia v poliklinike.

Out of 1700 patients suffering from chronic gastritis, a group of 221 patients followed up for 6 to 14 years at an outpatient clinic was distinguished. Endoscopy and biopsy of gastric mucosa areas with focal lesions were carried out annually. 140 patients were discovered to have atrophic hyperplastic gastritis, 81 "complete" erosions". The lesions were of solitary or multiple character and were coupled with the other manifestations of chronic gastritis. Histology revealed different manifestations of chronic atrophic gastritis. 7.2% of the patients showed moderate dysplasia of the epithelium. The follow-up of focal hyperplasias established invariability of those formations or occurrence of the new ones in 89% of cases. In patients with "complete" erosions, such a course was recorded in 47% of cases whereas in the remainder, there was a decrease or complete disappearance of the sign. Dynamics of the histological appearance available in 28% of the patients, lay in atrophy enhancement and in the appearance of foci of intestinal metaplasia. In an equal number of cases, dysplasia of the epithelium was invariable; in some cases, it disappeared or else its intensity changed (within the framework of mild and medium degree).

[Gastroscopy in follow-up studies of patients with chronic atrophic gastritis and diagnosis of early gastric cancer]. / Gastroskopiia v dispansernom nabliudenii za bol'nymi khronicheskim atroficheskim gastritom i diagnostike rannego raka zheludka.

Visual assessment of gastric mucosa and histological findings in biopsies from the lesions were compared for 1806 patients with chronic atrophic gastritis. The spectrum of the focal lesions appeared wide. Morphological examinations determined basic comparable structural elements typical for atrophic gastritis. 85 patients were diagnosed to have early gastric cancer. All the cancer patients suffered from chronic atrophic gastritis and developed in 88% of cases intestinal metaplasia, in 32% severe epithelial dysplasia. Focal changes in the mucosa characteristic for early gastric cancer in 64% of cases could be considered as variants of chronic atrophic gastritis. In 52 patients cancer was identified during the follow-up, new-onset macroscopic alterations emerging in the last year in 62% cancer subjects. The rest of them had long-lasting macroscopic lesions, among them severe dysplasia of the epithelium in 65% of cases, believed to be histological variants of atrophic gastritis. Early cancer is suggested to develop in the presence of previous lesions rapidly and discretely.