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PubMed1981

Some psychophysical determinants of discrete Moiré patterns.

In a series of experiments we have investigated the perception of Moiré patterns as a function of spatial density, rotation and temporal display parameters. Results indicate that the local correlation extraction processes involved in the perception of these patterns is not feature specific, yet is driven by excitatory (correlated) and inhibitory (uncorrelated) information under a form of spatial summation. These results are comparable with recent results on texture discrimination where texture interpoint distance distributions (dipole statistics) have also been discovered to have excitatory and inhibitory components.

Form Perception↗

PubMed1981

An advanced version of the dynamic receptor pattern generation model: the flux model.

In the recently described simple model of dynamic receptor pattern generation we used a two dimensional hexagonal area of a regular triangular network, formed by a statistically constant distribution of unit electostatic changes in a dynamic equilibrium. A set of 16 trnasition rules was applied to all units simultaneously; the next state of each unit depended only on the previous state of its six nearest neighbours, and the transition of the total pattern into the new one occurred in a single jump. Hence we designated the initial simple model as "jump model". In this paper we described an advanced version of the model, in which simplified rules are applied to one unit after the other in a sequential order, from left to right, starting with the top row of units. In the advanced version the state of a unit depends not only on that of its six nearest neighbours, but also on the state of all units preceding in sequence the one actually considered. This results in flux-like transitions. We therefore designated the advanced version as the "flux model". It is shown that the flux model represents a closer approximation of physical and biological realities than the original jump model.

Animals↗

PubMed1995

Prevalence of sexual abuse among patients with functional disorders of the lower gastrointestinal tract.

To evaluate the links between gastrointestinal disorders and sexual abuse, we asked 344 patients consulting in a specialized tertiary care university hospital or a gastroenterologist in private practice, if they had been sexually abused. Forty per cent of patients suffering from lower functional digestive disorder gave a history of having been victims of sexual abuse in contrast to only 10% of patients with organic diseases (P < 0.0003). The prevalence was similar in private practice and in the university hospital. Abused patients were more likely to complain of constipation (P < 0.03) and diarrhoea (P < 0.04). Anismus was more frequent in patients who had been sexually abused (P < 0.02). The prevalence of abuse was four times greater in patients with lower than with upper functional motor disorders of the gastrointestinal tract (P < 0.002). This study confirms the large prevalence of a past history of sexual abuse among patients consulting for gastrointestinal tract functional disorder, and this whatever the kind of recruitment may be. It shows the association to be much stronger in patients who have a lower rather than an upper gastrointestinal dysfunction, the major complaint of abused patients being constipation and diarrhoea.

Adolescent↗

PubMed1986

Overnight metabolic profiles in very young insulin-dependent diabetic children.

UNLABELLED: The magnitude of the disturbance of metabolic control in diabetes mellitus in very young children has been recognised, but seldom studied. Limitations to studies are set by the difficulty of obtaining control data and until recently the lack of alternative therapies. Recently "mini" pumps for continuous subcutaneous insulin delivery have become available and may offer an alternative therapeutic possibility. The present investigation has been undertaken to collect overnight metabolic data of very young diabetic children (less than 6 years) controlled by standard injection therapy. During one admission to hospital frequent blood samples were collected for free insulin, glucose, alanine, lactate, glycerol and 3-hydroxybutyrate determinations. In all children (n = 9) the profiles showed a steep rise in glucose from 04.30 h (6.2 +/- 1.3 mmol/l) to 09.30 h (17.8 +/- 2.4 mmol/l) (the so-called "dawn-phenomenon"). The nature of the changes in the intermediary metabolites suggested that rise in blood glucose was caused by insufficient insulin. We have attempted to explore the time relationship between the overnight drop in free insulin levels and the rises in blood glucose by a distribution-free statistical analysis, correlating successive changes in time between the two profiles. The analysis suggested a delay of 2-6 h between free insulin levels and their effects. IN CONCLUSION: a clear "dawn phenomenon" is seen in very young diabetic children, and contributes to their poor glycaemic control. More stable and higher insulin concentrations in the early morning, obtained perhaps by continuous subcutaneous insulin infusion, might ameliorate the overall glycaemic control in the very young diabetic child.

Age Factors↗

PubMed1982

Changes in [3H]galactose uptake in human colonic mucosa with carcinoma: an ultrastructural study.

As part of our investigation on glycoprotein synthesis in pre-malignant colonic epithelium, changes in the uptake of [3H]galactose were studied at the ultrastructural level. Normal control mucosa from rectal biopsies of patients with no known gastro-intestinal disease and mucosa adjacent to carcinoma ('transitional' mucosa) from specimens resected for colo-rectal cancel were compared. These tissues were incubated in TC 199 medium containing [3H]galactose for various intervals of time and for pulse labelling. Silver grain distribution was statistically analysed. The results showed a reduction in the incorporation of the galactose by 'transitional' mucosa. The uptake by this mucosa was less uniform than normal and showed considerable peaking in the endoplasmic reticulum of the goblet cells and in the Golgi of the absorptive cells, suggesting a blockage or alteration in glycoprotein synthesis. The differences were most marked in the middle crypt (the region of differentiation) and in the upper crypt (the region of maturation).

Colon↗

PubMed1989

Lymphocytic (microscopic) colitis. Clinicopathologic study of 18 patients and comparison to collagenous colitis.

Lymphocytic colitis, formerly called microscopic colitis, is a clinicopathologic syndrome with chronic watery diarrhea and diffuse mucosal inflammatory changes with prominent intraepithelial lymphocytes. The 18 lymphocytic colitis patients studied presented with chronic watery diarrhea at a mean age of 53.8 +/- 17 years (+/- 1 SD). Roentgenographic, endoscopic, and culture data were not diagnostic. In patients tested, there was a high prevalence of arthritis (82%) and autoantibodies (50%) but no increase in frequency of histocompatibility antigens associated with well-defined autoimmune disease (DR3, B8). Lymphocytic colitis patients were compared to 21 patients with collagenous colitis. Similarities included age, symptomatology, and nondiagnostic radiographic and endoscopic studies. However, the sex distribution was statistically different, with an equal male-to-female ratio in lymphocytic colitis and female predominance (80%) in collagenous colitis. Other differences included dissimilar histocompatibility phenotypes and collagen band on biopsies of collagenous but not lymphocytic colitis. These findings suggest that lymphocytic and collagenous colitis may be related yet distinct disorders.

Adult↗

PubMed1988

The use of a personal computer for trend data analysis with the Ohmeda 3700 pulse oximeter.

The Ohmeda 3700 pulse oximeter provides trend data storage of arterial oxygen saturation (SaO2) and pulse rate measurements for a maximum of 8 hours. This feature allows the oximeter to be used as a stand-alone unit for overnight studies of saturation during sleep. Subsequent transfer and processing of the stored SaO2 data requires additional software. We present a program for data processing that uses the Lotus 1-2-3 program on IBM and compatible microcomputers and that performs a data distribution and statistical analysis on these trend data and presents them in graphic form. Processing SaO2 trend data within the Lotus 1-2-3 worksheet format allows the user to easily add to or modify the program presented here, depending on individual needs.

Adult↗

PubMed1977

Precision of analysis for waterborne chrysotile asbestos by transmission electron microscopy.

Detailed examinations of water samples were carried out to determine the precision of analysis for chrysotile asbestos by transmission electron microscopy (TEM). Since the frequency distribution of counts fits a Poisson distribution, several statistical inferences were made, including (1) an estimate of precision, and (2) a model for determining the probability of observing chrysotile as a function of its concentration in water and magnitude of area scanned by TEM.

Asbestos↗

PubMed1986

Statistical properties of molecular tree construction methods under the neutral mutation model.

The statistical properties of three molecular tree construction methods--the unweighted pair-group arithmetic average clustering (UPG), Farris, and modified Farris methods--are examined under the neutral mutation model of evolution. The methods are compared for accuracy in construction of the topology and estimation of the branch lengths, using statistics of these two aspects. The distribution of the statistic concerning topological construction is shown to be as important as its mean and variance for the comparison. Of the three methods, the UPG method constructs the tree topology with the least variation. The modified Farris method, however, gives the best performance when the two aspects are considered simultaneously. It is also shown that a topology based on two genes is much more accurate than that based on one gene. There is a tendency to accept published molecular trees, but uncritical acceptance may lead one to spurious conclusions. It should always be kept in mind that a tree is a statistical result that is affected strongly by the stochastic error of nucleotide substitution and the error intrinsic to the tree construction method itself.

Biological Evolution↗

PubMed1997

Interindividual variations in cytokine levels following cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) is associated with an inflammatory response, mainly caused by the trauma of surgery, contact of blood with the artificial surface of the circuit, and reperfusion injury, resulting in increased capillary permeability, respiratory distress, low cardiac output, and multiorgan failure. The inflammatory reaction includes an activation of the humoral and cellular immune system with enhanced release of cytokines. The present study focused on the effect of CPB on the time course of pro- and anti-inflammatory cytokines. In 20 patients undergoing coronary artery bypass grafting, the plasma concentration of interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-2, IL-4, IL-6, IL-8, and IL-10 was investigated pre-, intra-, and postoperatively by enzyme-linked immunosorbent assay technique. With the exception of IFN-gamma, all the other cytokines could be detected in the patients plasma. However, neither TNF-alpha nor IL-1 beta and IL-2 revealed significant changes in concentration during the investigated time period. In contrast, IL-6 and IL-8 levels peaked early postoperatively, reaching median concentrations of 430 pg/ml (221 pg per ml/558 pg per ml; lower/upper quartiles, respectively) and approximately 12 pg/ml (0/17 pg/ml; lower/upper quartiles, respectively). IL-4 and IL-10, respectively, revealed maximal concentrations of approximately 2 pg/ml (0/39 pg/ml; lower/upper quartiles, respectively) and 208 pg/ml (76 pg per ml/380 pg per ml; lower/upper quartiles, respectively) immediately after protamine administration, preceding the maximal concentration of IL-6. The degree of the observed modulation of cytokine patterns during and after CPB seemed to be patient-dependent, since large interindividual variations in cytokine levels were observed, not only preoperatively, but especially during and following CPB. However, IL-6 and IL-10 showed the least interindividual variations, suggesting that these cytokines may give reliable information regarding modulation of the immune response following CPB and its consequences for the patient's outcome.

Adult↗

PubMedDate not supplied

Iodine deficiency disorders in Bangladesh.

An extensive iodine deficiency disorders survey was conducted in Bangladesh in 1993 to assess the latest iodine nutriture status of the country. The clinical variables of the survey were goitre and cretinism, and the biochemical variable was urinary iodine. The "EPI-30 cluster" sampling methodology was followed for selecting the survey sites. In each survey site, the study population consisted of boys and girls, aged 5-11 years, and men and women, aged 15-44 years, in about equal populations. The total number of survey sites was 78 and the total number of respondents was 30,072. The total number of urine samples was 4512 (15% sub-sample). The current total goitre rate (grade 1 + grade 2) in Bangladesh is 47.1% (hilly, 44.4%; flood-prone, 50.7%; and plains, 45.6%). The prevalence of cretinism in the country is 0.5% (hilly, 0.8%; flood-prone, 0.5%; and plains, 0.3%). Nearly 69% of Bangladeshi population have biochemical iodine deficiency (urinary iodine excretion [UIE] < 10 mg/dl) (hilly, 84.4; flood-prone, 67.1%; and plains 60.4%). Women and children are more affected that men, in terms of both goitre prevalence and UIE. The widespread severe iodine deficiency in all ecological zones indicates that the country as a whole is an iodine-deficient region. Important recommendations of global interest are made from the experience of the survey.

Adolescent↗

PubMedDate not supplied

Thyroid abnormalities in lithium-treated patients.

The purposes of this study were to evaluate possible effects of lithium on thyroid function, determine the relationship among thyroid function, antibody levels, and demographic/clinical variables, and establish the prevalence of lithium-related goiter, clinical hypothyroidism, and thyroid antibodies. Forty-nine patients who had taken lithium for a minimum of 6 months were enrolled, as were 46 age- and sex-matched controls naïve to lithium use. Blood was drawn to measure levels of total and free T3, T4, thyroid-stimulating hormone (TSH), and antimicrosomal and antithyroglobulin antibodies. Thyroid volume was quantified on ultrasonography. Twenty-nine patients in the study group (59%) and 7 in the control group (15%) had goiter. Free T4 levels were significantly lower in the study group, and TSH levels were higher. Among lithium-treated patients, 12% had clinical hypothyroidism and 2% had subclinical hypothyroidism. Thyroid antibodies were present in 23% of the lithium group and 15% of the control group. No significant relationship was apparent among thyroid antibodies, thyroid volume, and clinical hypothyroidism. Our findings suggested that along with its goitrogenic effects, lithium inhibited thyroid function and led to clinical hypothyroidism. Older age, family history of thyroid disorders, and the presence of thyroid antibodies significantly influenced thyroid function in the present study.

Adult↗

PubMed1999

Correlates of a perceived need for mental health assistance and differences between those who do and do not seek help.

BACKGROUND: This study examined prevalence of perceived need for mental health assistance, characteristics of people with a perceived need, and how persons with a need who sought help were different from those who did not. METHODS: A national random phone survey (n = 1,394) was conducted in Israel, which included questions about (1) perceived need for mental health assistance and (2) help seeking. RESULTS: Prevalence of life-time and recent perceived need for males was 21% and 10.7%, and for females 31% and 15.1%. Of those with a perceived need, 31.4% of males and 41.6% of females had gone for help. Based on logistic regression models, the variables associated with need were being female, divorced, having a chronic physical disease, and low income (for males only), while predictors of help seeking were living in a big city and not being a recent immigrant. The major sources of help in descending order were: mental health professionals (46%), family physician (25%), family or friends (19%), and other (10%). CONCLUSIONS: A majority of people who feel that they need help for mental health problems do not get help.

Adult↗

PubMed2004

Genetic polymorphism of NK receptors and their ligands in melanoma patients: prevalence of inhibitory over activating signals.

Antitumor cytotoxicity of NK cells and T cells expressing NK-associated receptors is regulated by interaction between their cell surface killer immunoglobulin-like receptors (KIRs) and CD94/NKG2 heterodimers with MHC class I ligands on target cells. To test the hypothesis that KIR and/or HLA polymorphisms, and KIR/HLA combinations could contribute to the tumorigenesis, association studies were performed in 50 patients with malignant melanoma (MM) in different stages of disease and 54 controls. Our data showed that the frequency of inhibitory and activating KIR genes and KIR genotypes did not differ significantly between healthy individuals and melanoma patients. HLA haplotype distribution showed statistically significant increased frequencies of A*01-B*35-Cw*04 (0.069 vs 0.000; pc < 0.05; OR = 19.9), A*01-B*08-DRB1*03 (0.079 vs 0.019; pc < 0.05; OR = 4.5), and A*24-B*40-DRB1*11 (0.026 vs 0.000; pc < 0.05; OR = 7.1) in melanoma patients compared with healthy controls. Individuals homozygous for group 2 HLA-C ligands were less frequent in the patient group compared with the control cohort (12% vs 31.5%; p < 0.017). In addition, we observed an increased frequency (88.0% vs 68.5%; p = 0.017; OR = 2.80) of KIR2DL2/2DL3 in combination with their group 1 HLA-C ligands, while the presence of these KIRs in the absence of the putative ligands was decreased (12.0% vs 31.5%; p = 0.017) in the patient group. Furthermore, an increased frequency of activating KIR2DS1 in the absence of the putative HLA-C(Lys80) ligands was found in melanoma patients (16.0% vs 9.2%). In contrast, KIR2DS2 was absent in patients more often (38.0% vs 25.9%) when the presumptive HLA-C(Asn80) ligands were present. A slightly higher incidence of KIR3DL1 in combination with the less effective Bw4(Thr80) ligands was seen in patients with primary (20.8%) compared with metastatic (4.2%) disease. The data obtained in this study imply that there may not be a direct association between KIR gene content in the genome and the presence of malignant melanoma, or melanoma progression. However, some HLA haplotypes could be predisposing to MM in the Bulgarian population. Furthermore, distinct KIR/HLA ligand combinations may be relevant to the development of malignancy whereby inhibition overrides activation of NK cells and T cells expressing NK-associated receptors, which in turn might facilitate tumor escape and progression.

Adult↗

PubMed2001

Body mass index as a predictor of outcome in total knee replacement.

The clinical and radiographic outcomes of 326 total knee replacements (TKR) in 285 osteoarthritic patients with body mass index (BMI) greater than 30 kg/m2 were compared with the results of a matched group of 425 TKR in 371 patients with BMI less than 30 kg/m2. At an average follow-up of 75.9 (48-144) months the Knee Society score (KSS) in the obese patients had increased by 41.9 points, and the joint score by 43.7. In the non-obese group the KSS rose by 40.2 points and the joint score by 42.6 points. Although patients with BMI greater than 40 kg/m2 achieved a lower final KSS the 'absolute improvement' appeared to be independent of BMI. Of the obese patient group 4.9% underwent a revision of their TKR, compared with 3.1% of the non-obese group. Although linear osteolysis (radiolucency) rates were comparable, focal osteolysis rates were 5 times those of control subjects when the BMI exceeded 40 kg/m2. Ten-year survivorship figures were similar for both obese and non-obese patients.

Adult↗

PubMed2002

Outcome of histologically node-negative esophageal squamous cell carcinoma.

The outcome of node-negative esophageal carcinoma and the prognostic significance of lymph node micrometastasis remain unknown. The aim of this retrospective study was to clarify these two points. A series of 98 patients who underwent curative operation for histologically node-negative (pN0 in TNM classification) esophageal carcinoma were enrolled in the study. We reviewed the cause of death of these patients. The survival curves were calculated and compared after stratifications according to clinicopathologic parameters. Lymph node micrometastasis in the patients with recurrences was examined using immunohistochemical staining of cytokeratin. Their ages ranged from 45 to 83 years (mean 64.3 years). There were 83 men and 15 women. Altogether, 54 patients were still alive, and 44 had died. A total of 9 patients died from recurrence of their esophageal carcinoma, 33 died from other causes (pneumonia 11, extraesophageal carcinoma 7, and so on), and 2 died from unknown causes. Eight patients had locoregional recurrences, and two patients had distant recurrences. The overall survival rate for the 98 patients was 58.2%. The survival for patients with pT2 or pT3 tumors was significantly worse than for those with pTis or pT1 tumors (p = 0.02, log-rank test). Other clinicopathologic factors did not affect the prognosis. Immunohistochemical study found no lymph node micrometastasis in 365 lymph nodes resected from the patients with recurrences. Only the depth of tumor invasion affected the outcome of patients with node-negative esophageal carcinoma. Altogether, 75% of patients died of other causes without recurrence, with the two main causes of death being pulmonary complications and extraesophageal carcinoma in these patients. Lymph node micrometastasis was not associated with recurrence in this series.

Adult↗

PubMed2002

Multifactorial risk profile for bone fractures in primary hyperparathyroidism.

Primary hyperparathyroidism (pHPT) is associated with an increased fracture risk, and decreased bone density thus has been considered an indication for surgery. However, many pHPT patients have a multifactorial risk profile for osteoporosis and bone fractures. The aim of the present study was to evaluate variables associated with fracture risk within the group of pHPT patients. A series of 203 consecutive patients operated for pHPT were investigated with bone mineral content and biochemical and clinical risk factors for bone fracture. Seventeen patients (8%) had a history of at least one bone fracture up to 5 years before pHPT surgery. Twenty-six patients (13%) had a history of at least one fracture during the 10-year period prior to surgery. In the univariate analyses corticosteroid treatment, serum levels of alkaline phosphatase, 25-hydroxyvitamin D3, type I collagen telopeptide, and bone mineral content were found to be associated with a history of bone fractures up to 10 years before surgery. Additionally, age and menopausal status were of importance for fractures during the 10-year-period, whereas a history of cardiovascular disease was important for fractures during the 5-year-period prior to surgery. Multivariate analyses showed that serum level of PTH was independently associated with bone fractures during the 5-year period prior to pHPT surgery and further that serum level of 25-hydroxyvitamin D3 was associated with fractures up to 10 years before surgery. In conclusion, serum levels of 25-hydroxyvitamin D3 and PTH were independently associated with a history of bone fractures in pHPT. These variables should be considered when evaluating patients for parathyroid surgery.

Absorptiometry, Photon↗

PubMed2004

Deterioration of hepatic functional reserve in patients with hepatocellular carcinoma after resection: incidence, risk factors, and association with intrahepatic tumor recurrence.

Hepatocellular carcinoma (HCC) is frequently associated with liver cirrhosis. Patients with HCCs undergoing surgical resection may have declining hepatic functional reserve over time. However, the incidence and risk factors of hepatic decompensation, and its relation to postoperative tumor recurrence are unknown. This study investigated 241 HCC patients (208 male; age 61 +/- 13 years) undergoing resection with a long-term follow-up. The Child-Pugh scoring system was used to evaluate the postoperative deterioration of liver reserve, defined as a sustained increment in the Child-Pugh score by 2 or more. The 1-, 3-, and 5-year cumulative probabilities of postoperative decompensation were 14%, 32%, and 56%, respectively, during a follow-up period of 27 +/- 18 months (range 3-75 months). The average increment in Child-Pugh score was 1.4 +/- 1.1 in 2.3 +/- 1.5 years, or 0.6 point per year. Altogether, 74 (31%) patients developed postoperative hepatic decompensation during the follow-up period, 43 (58%) of whom had decompensation within 2 years of resection. Large (> 3 cm) tumor size was the only independent predictor associated with hepatic decompensation (relative risk 1.7, 95% confidence interval 1.1-2.8, p = 0.041) and was a significant risk factor for intrahepatic tumor recurrence ( p = 0.018). Patients with tumor recurrence more frequently (40% of 109 patients vs. 23% of 132 patients, p = 0.005) and more rapidly (0.8 vs. 0.4 point per year) developed hepatic decompensation than those without recurrence. In conclusion, large HCCs are closely associated with hepatic decompensation in patients after resection. Tumor recurrence may predispose to the development of hepatic decompensation in these patients.

Age Distribution↗