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We present a robust method for computing the reflection of arbitrarily shaped and sized beams from finite thickness photonic crystals. The method is based on dividing the incident beam into plane waves, each of which can be solved individually using Bloch periodic boundary conditions. This procedure allows us to take a full advantage of the crystal symmetry and also leads to a linear scaling of the computation time with respect to the number of plane waves needed to expand the incident beam. The algorithm for computing the reflection of an individual plane wave is also reviewed. Finally, we find an excellent agreement between the computational results and measurement data obtained from opals that are synthesized using polystyrene and poly(methyl methacrylate) microspheres.

We present a robust and accuracy enhanced method for analyzing the propagation behavior of EM waves in z-periodic structures in (r, ö, z)-cylindrical co-ordinates. A cylindrical disk, characterized by the radius a and the periodicity length Lz, defines the fundamental cell in our problem. The permittivity of the dielectric inside this cell is characterized by an arbitrary, single-valued function å(r, ö, z) of all three spatial co-ordinates. We consider both open and closed boundary problems. Irrespective of the type of the boundary conditions on the surface r = a, our method requires the discretization of the fields in the interior of the disk only. Inside the disk volume, we expand the fields in terms of planewaves on discrete cylindrical surfaces ri = i, with being the discretization step length. The fields on the nested surfaces ri = i in the interior of the simulation domain are interrelated by the application of a simple, yet, powerful finite difference scheme. In free space outside the disk, the fields are xpanded in terms of the closed-form eigensolutions of the Maxwell's equations in cylindrical co-ordinates. In order to uniquely determine the involved unknown coefficients, the solutions in the interior- and exterior domains are matched on the disk's bounding surface. Our formulation utilizes a radially-diagonalized form of Maxwell's equations, and merely involves four (out of the six) field components. It is demonstrated that our formulation is perfectly suited, but by no means limited, to cylindrical symmetric problems.

Background/aims: To evaluate the usefulness of the endoscopic Congo red test (ECRT), and to compare sensitivity and specificity of different tests in the discrimination of cases with high risk for postvagotomy recurrent ulcer (RU)., Methodology: In 271 consecutive postvagotomy duodenal ulcer patients the endoscopic Congo red test (ECRT) was used 5-12 years after vagotomy. Further, 39 patients out of 271 were selected and classified into two groups: A--13 ECRT positive cases with RU, B--26 controls without RU (13 ECRT positive and 13 ECRT negative cases). Basal acid output (BAO), maximal acid output (MAO), and nocturnal acid output (NAO) were determined pre- and postoperatively, the serum pepsinogen I (S-PGI) and insulin test were estimated postoperatively., Results: Positive ECRT had 95% sensitivity and 53% specificity for RU. S-PGI > 150 microg/l had 54% sensitivity and 92% specificity (in ECRT positive cases 100% specificity). The insulin test showed 83% sensitivity and 78% specificity. The respective data for the combination of BAO > 1.5 mmol/h + NAO > 30 mmol/12 h were 80% and 81%., Conclusion: ECRT should be a primary step in estimating postvagotomy ulcer risk. In negative ECRT cases, the development of recurrent ulcer is unlikely. Additional gastric secretion studies as S-PGI or BAO+NAO or insulin test are needed only in ECRT positive cases.

Objectives: To evaluate the role of gastrointestinal and psychiatric etiology in globus sensation., Methods: The study population consisted of 32 consecutive patients with globus sensation without dysphagia referred to the Department of Otorhinolaryngology in Helsinki University Hospital. Eleven patients were excluded from the study: two because of advanced age, one prisoner, and six patients refused further studies. Only two patients (6%) were found to have abnormal otorhinolaryngological status. These patients were also excluded from the study. Esophagogastroduodenoscopy, 24-h pH recording, esophageal manometry, and Bernstein acid perfusion test were carried out in 21 patients (13 females, eight males, mean age 49 yr). Psychiatric evaluation was done in 20 patients; one patient refused the psychiatric consultation., Results: Abnormal endoscopy was found in 12/21 (57%) of the patients, with antral gastritis and hiatal hernia being the most common findings. Two patients had esophagitis. Sixty-seven percent demonstrated abnormalities in esophageal manometry, the most frequent finding being a nonspecific esophageal motility disorder (29%). pH monitoring was normal in 16/21 of patients (76%), whereas the Bernstein test showed positive results in 13/21 (62%). With DSM IIIR as the diagnostic tool, five of 20 patients (25%) received a psychiatric diagnosis., Conclusions: Globus sensation has a multiple etiology, and local reasons are rare but should first be ruled out. Abnormalities in esophageal motility are commonly found, and these patients seem to be sensitive to esophageal acidity. Esophageal manometry and ambulatory 24-h pH recording should be included in the evaluation of a globus patient. The number of psychiatric disorders does not differ from that in the general population. Treatment of globus sensation should be directed toward the abnormality found behind the symptom.

Immunocytochemical studies have demonstrated the existence of five different types of peptic cells in man. These are chief and mucus neck cells in fundic gland mucosa, the pyloric glands in antral mucosa, and the cardiac and Brunner's glands. There are two immunochemically distinct groups of pepsinogens, pepsinogen group I (PG I) and pepsinogen group II (PG II). Chief cells and mucous neck cells in fundic gland mucosa contain both PG I and PG II. Cardiac gland cells, pyloric gland cells and cells in Brunner's glands are clear staining (with hematoxylin and eosin) and usually contain only PG II. On occasion, faint positivity with PGI antiserum may be found in clear staining pyloric gland cells. Gastric gland heterotopia and metaplasia of fundic or pyloric type may be found anywhere in the gastrointestinal tract, but most often in the distal esophagus and duodenal bulb. Heterotopic and metaplastic gastric cells contain pepsinogens similar to the normal peptic cells in the stomach: chief-type cells contain both PG I and PG II, and clear staining cells only PG II. In the presence of hydrochloric acid, the production of pepsinogens may cause local peptic digestion outside of the stomach.

Relative chief and parietal cell volume densities were estimated morphometrically in the remnant mucosa of 98 male patients ("series"), operated on for duodenal ulcer by the Billroth II, and in the body mucosa of 55 subjects, age and sex matched, from a random series of a Finnish population ("controls"). The relative volumes of chief and parietal cells were significantly lower in the series than in the controls. The mean chief cell: parietal cell ratio was significantly higher in the series than in the controls. In the controls the ratio decreased with increasing loss of normal tubules. However, no such decrease was discernable in the series, owing to wide scatter of the individual ratios. High ratios (greater than or equal 2.0) were found in 17 cases of the series and in one of the controls. These 17 patients with high ratios had a significantly higher mean length of the foveoles and a significantly lower mean score of the round cell infiltration than the operated patients with lower ratios.

Gastritis is an inflammation in the gastric mucosa. The definition, classification and diagnosis of gastritis is based on morphological changes. The term 'gastritis' is widely used as a catchbag for upper abdominal complaints. Although acute or specific forms of gastritis may present upper abdominal symptoms, chronic gastritis is asymptomatic, and is not the cause of long standing upper abdominal complaints. Chronic gastritis is a very common condition in the general population. Hence the probability of finding chronic gastritis in endoscopic biopsies of patients with upper abdominal complaints is high for statistical reasons, and this does not prove any causal relation between chronic gastritis and subjective complaints. Campylobacter pylori is associated with chronic gastritis. It may activate the inflammatory process in the gastric mucosa, or it may just be an innocent bystander, which subsists within a diseased mucosa. The role of campylobacter pylory in the etiology of non-ulcer dyspepsia or peptic ulcer is questionable.

The annual number of hospital discharges for peptic ulcer decreased in Finland from 1969 to 1974, mainly because of a smaller number of men with uncomplicated peptic ulcer disease. After the mid-1970s the number of hospital admissions remained stable, whereas the number of elderly patients increased. From 1979 to 1984 the number of hospitalizations for perforated ulcers remained stable, whereas those for ulcer haemorrhages increased, the increase being most marked in the older age groups. The age-specific mortality from peptic ulcer remained stable from 1969 to 1984 and rose thereafter among old patients. The risk of death from peptic ulcer was about 10-fold higher in patients over 75 years old than in younger age groups, and about half of the deaths caused by peptic ulcer occurred in patients over 75 years old. The men to women ratio among hospitalized patients decreased from 3.5 in the late 1960s to 2.1 in the 1980s, and the gastric ulcer to duodenal ulcer ratio was about 1.1 throughout the observation period.

Gastrointestinal functions such as food intake, propulsive peristalsis, inhibition of reflux, secretion, digestion and defecation are controlled by a complex autonomous neurohumoral system, which is influenced by higher cortical impulses. Life stress may modulate these impulses and in this way cause two types of gastrointestinal reactions. Psychophysiological reactions involve accentuations, inhibition or distortion of the pattern of function of gastrointestinal organs without changes in their structure. Examples of this type of reaction are often painful accentuation of bowel movements in patients with the irritable bowel syndrome, and increased gastric secretion elicited by emotional stress. Psychosomatic reactions lead to morphological changes in the end organ, e.g. activation of peptic ulcer or ulcerative colitis. Psychophysiological reactions may be important in the onset of symptoms in some functional diseases, e.g. in the irritable bowel syndrome. These patients need support from the physician, but specific psychiatric therapy is required only in cases with severe psychopathology, e.g. in patients with anorexia nervosa. The role of psychosomatic reactions in the development of organic gastrointestinal diseases is still unclear, as is the value of specific psychiatric therapy in the treatment of diseases such as peptic ulcer or ulcerative colitis. If this kind of therapy has some effect, it may be directed mainly towards subjective symptoms.

Two family samples, (i) a sample considered to represent the population at large (431 subjects) and (ii) a sample of first-degree relatives of index subjects (IS) with overt pernicious anaemia (183 subjects) were analyzed in order to evaluate the onset and course of chronic gastritis (CG) and the pathogenetic factors involved with special reference to the effects of genetic variation. The analysis was based on data obtained from two generations: first generation (sibs of the IS) and second (children of the IS). Formulae derived from Poisson process were used for age-correction of the gastritic changes. Otherwise, conventional statistical methods were used in the genetic analysis and the calculation of prevalences of CG. This approach enabled us to achieve a classification of gastritis into more specific subgroups and to evaluate the natural course of the disease. The progression of gastritis in the second generation (children; mean age 35 years) was roughly similar in antrum and body, indicating that gastritis starts as a diffuse process affecting both areas of the stomach to a rather similar degree. The start of CG and its progression is at least to some degree influenced by genetic factors and probably regulated by the male sex. Thus nearly all children of male IS's with a non-atrophic mucosa (normal mucosa or superficial gastritis) showed a normal mucosa suggesting the existence of a particular sex-bound, genetic mechanisms. These mechanisms may prevent or delay the progression of gastritis up to middle age, when a change in dynamics occurs leading to formation of more specific subtypes of CG. In the first generation (mean age 60 years) CG dispersed into more specific subtypes (corresponding to types A and B of Strickland and McKay and type AB of Glass) and to more advanced stages, which were connected with a higher than expected prevalence of advanced stages also in the relatives. The families of IS's with type A atrophic gastritis (AG) (severe AG in the body but no AG in antrum), type B (AG in antrum but no AG in body) and type AB AG (AG in both antrum and body) showed typical dynamic patterns of the age-specific prevalences of AG. Genetic calculations showed that the type A of AG found in pernicious anaemia patients and their relatives is inherited by a simple dominant gene, while this type of inheritance is statistically unlikely in the type B of AG. The type B, on the other hand, exhibited characteristics that indicate a recessive Mendelian inheritance.(ABSTRACT TRUNCATED AT 400 WORDS)

Campylobacter pylori is supposed to be involved in the pathogenesis of gastroduodenal peptic ulcer diseases and chronic gastritis. In order to study whether the Campylobacter pylori in the stomach of peptic ulcer patients is related to ulcer itself or to a co-existing chronic gastritis, we examined the frequency of the bacteria in Giemsa stained histological sections of biopsy specimens from a series of patients with active peptic ulcer and from series of non-ulcer control subjects. We found no difference in the frequency of Campylobacter- positive cases between ulcer patients and non-ulcer controls when the comparison was done within the same category of chronic gastritis; e.g., within the category of chronic superficial gastritis 74% and 78% of cases showed the bacteria in antral biopsies from ulcer patients and from non-ulcer controls, respectively. In both ulcer patients and control subjects, in similar way in both antral and body mucosa, the Campylobacter pylori was strongly associated with chronic superficial gastritis but was more weakly associated with chronic atrophic gastritis, and the bacteria were only occasionally seen in normal mucosa. We conclude that Campylobacter pylori is associated with chronic gastritis in peptic ulcer patients but is not related to active ulcer.

34 subjects including 5 probands with pernicious anemia, 3 probands with severe atriphic body gastritis and 26 of their first-degree relatives were studied gastroscopically, bioptically, functionally and immunologically. In general, members of the same family revealed a trend to behave similarly with respect to the parameters studied. Signs of A-gastritis (severe atrophy of gastric body glands with a normal or almost normal antrum, achlorhydria, hypergastrinemia and parietal cell antibodies), with intrinsic factor antibodies in the gastric juice and diminished intrinsic factor secretion without anemia were found both in families of probands with atrophic gastritis and pernicious anemia. This suggests a close etiopathogenetic relation of this type of mucosal lesion to overt pernicious anemia. Determination of HCl output and serum gastrin level enabled us to distinguish two differently behaving subgroups in the series, one of them with characteristics of overt adult pernicious anemia. Very low intrinsic factor secretion was found almost exclusively in connection with the presence of intrinsic factor antibodies in the gastric juice and always with severe atrophy of gastric body glands.

311 first-degree relatives of 78 consecutive patients with gastric carcinoma and 386 first-degree relative of control probands computer matched from a large Finnish population were studied by means of biopsies from antrum and the fundus and by functional and immunological methods. Both the A and B type of Strickland the McKay as well as the AB types of Pitchumoni and Glass were discernable in the present series and often accumulated in the same families. Particularly the A type associated with high serum gastrin values and parietal cell antibodies revealed a family accumulation. In general members of the same family tended to behave similarly with regard to morhology, function and immunology of the antro-fundal mucosa. The 386 computer matched controls from the general population were treated by means of mathematical methods derived from stochastic theory. It appeared that on a family level there was clearly discernable a line representin families with predominance of fundal gastritis (A type?) which significantly deviated from the main population. However, no such behavior was found as to the families with predominantly antral gastritis (B type?) which behaved like the population at large.

The course of antrum and body gastritis was studied using an essentially linear multicompartmental model in pernicious anemia probands, their first-degree relatives, and controls consisting of a representative family sample of a large Finnish population. Our earlier dynamic approach showed that progression of body gastritis was virtually identical in a series followed up with biopsies and in cross-comparison analyses, indicating that cross-sectional data can be used for dynamic analyses at a population level. The collected data fitted a model which consisted of stepwise progression of body gastritis to severe atrophy, of corresponding progressive steps for antral gastritis, and of regression of the antral changes after the end-stage of the body process had been reached. In addition, acceleration of the progression of gastritis in older subjects had to be taken into account in the model construction. The main findings which characterized pernicious anemia probands and their close relatives were: (1) a rapid overall progression of body gastritis particularly after 50 years of age; (2) a very rapid progression of body atrophy in its final stages, which was unrelated to age; (3) the occurrence of juvenile severe body atrophy; and (4) the healing of antral gastritis which was most marked at the stage of superficial gastritis. These results may offer a dynamic explantation for the occurrence of severe body atrophy in association with a normal or slightly altered antral mucosa in pernicious anemia and the prepernicious anemia state.

We report here a variance component analysis of the distribution of serum pepsinogen I levels in normal individuals, using a maximum-likelihood method on entire pedigrees. The results indicate a broad heritability of 91%, with some 74% being attributed to a dominance component. This is consistent with the hypothesis that the pepsinogen I level in normals is principally determined by the action of major genes, as also seems to be the case for duodenal ulcer patients and families.