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Biomedical subjects

F Arnold

Publications and source records attributed to F Arnold.

At least 19 recordsLinked to original sources
PubMed2006

Epidemiology of obesity and hypertension and related risk factors in Uzbekistan.

OBJECTIVE: This study examined the prevalence of obesity and hypertension and associated behavioral risk factors in adult men and women in Uzbekistan. The study also examined the association between obesity and hypertension. METHOD: The analysis used data from the 2002 Uzbekistan Health Examination Survey, which included a nationally representative sample of 2333 men aged 15-59 years and 5463 women aged 15-49 years. The survey measured height, weight and blood pressure and included questions on physical activity, dietary habits, tobacco smoking, alcohol use and other characteristics. The analysis was conducted using binary and multinomial logistic regression methods, separately for men and women. RESULTS: Eating animal source protein and tobacco smoking in the past were positively associated with obesity, but there were no consistent associations with other dietary indicators, physical activity level or alcohol use. Obese men and women were about three times as likely to suffer from hypertension as those with a normal BMI (odds ratio (OR)=3.01; 95% confidence interval (CI): 1.67-5.44; P<0.001 for men and OR=2.82; 95% CI: 2.05-3.86; P<0.001 for women), independent of physical activity level, dietary habits, tobacco smoking and other factors. For men, the risk of hypertension was strongly positively associated with BMI only at BMI levels above 25 kg/m(2), but for women a positive relationship was observed at all BMI levels. CONCLUSION: The study found a strong positive association between obesity and hypertension in adult men and women in Uzbekistan. The shape of the relationship between BMI and hypertension is different for women than for men, requiring further research to explore this relationship.

Adolescent↗
PubMed2006

The pneumonia severity index predicts time to clinical stability in patients with community-acquired pneumonia.

SETTING: A total of 33 hospitals in 13 countries in North America, Europe, Africa, Asia and Latin America. OBJECTIVE: To investigate the relationship between the pneumonia severity index (PSI) and the time to clinical stability from intravenous to oral antibiotic therapy in hospitalized adult patients with community-acquired pneumonia (CAP). DESIGN: An international, retrospective, observational study of random adult patients meeting the definition of CAP between June 2001 and May 2004. RESULTS: The risk class (RC) according to the PSI was calculated for all patients. The criteria to define when a patient is clinically stable were evaluated daily during the first 7 days of hospitalization in all patients. The mean time to clinical stability for 254 patients in RC I was 4.2 days, for 233 patients in RC II it was 3.9 days, for 395 patients in RC III it was 4.6 days, for 644 patients in RC IV it was 5.0 days and for 296 patients in RC V it was 6.0 days. Significant positive correlations were observed between RC and time to clinical stability (P < 0.0001). CONCLUSION: The PSI is a tool that can be used to predict time to clinical stability (i.e., time to antimicrobial switch therapy) in hospitalized patients with CAP.

Anti-Bacterial Agents↗
PubMed2005

[Band migration. A late complication of gastric banding].

BACKGROUND: Adjustable silicone gastric banding is an effective and safe treatment for morbid obesity. Migration of the band through the stomach wall is a long-term complication. The causes, clinical symptoms, timing, and incidence of band migration have not yet been investigated. METHODS: We report our experience over 9 years. Between February 1995 and February 2004, we performed adjustable silicone gastric banding in 161 patients, with follow-up of about 90.5% of cases. Mean follow-up time was 60.4 months. Cases of erosion were studied retrospectively. RESULTS: Eight patients (4.9%) developed band migration. In seven, the migration occurred between 30 and 86 months after band implantation. In one case, the migration occurred 10 months after laparoscopic repositioning of the band to avoid pouch dilatation. In all cases, the bands were removed. CONCLUSION: Band migration is a late complication after gastric banding that requires band removal. Various symptoms and complications of band migration influence the kind of band removal. The causes of band migration and its treatment are discussed.

Female↗
PubMed2005

Myelotoxicity of trichothecenes and apoptosis: an in vitro study on human cord blood CD34+ hematopoietic progenitor.

Previous studies have revealed that hematological disorders associated with trichothecenes intoxication in humans could result from hematopoiesis inhibition. The most frequent and potent trichothecene mycotoxins are T-2 toxin and deoxynivalenol (DON), respectively. Apoptosis induction by these two toxins was investigated in vitro on human hematopoietic progenitors (CD34+ cells). Hoechst coloration, DNA fragmentation and annexin-V/PI labeling in flow cytometry showed that T-2 toxin, in contrast to DON, induced apoptosis in CD34+ cells. T-2 toxin effect was dose- and time-dependent with a significant increase of apoptotic cells as early as 3h after incubation at 10(-7) M and a maximum reached at 12 h. This observation evidenced the high sensitivity of hematopoietic progenitors to T-2 toxin. The inhibition of T-2 toxin-induced apoptosis by a pan-caspase inhibitor (Z-VAD-fmk) suggested the involvement of caspases. The proportional increase of caspase-3 specific activity (DEVDase) with T-2 toxin concentration confirmed its role in the process. After incubation of CD34+ cells with T-2 toxin, in conditions that induced apoptosis, clonal expansion of granulo-monocytes, erythrocytes and megakaryocytes precursors was dose-dependently inhibited. The hematological effects observed in T-2 toxin mycotoxicosis could then be assigned to hematopoiesis inhibition by apoptosis. Different mechanisms that need to be further elucidated are involved in DON myelotoxicity.

Antigens, CD34↗
PubMed2004

Monitoring trends in under-5 mortality rates through national birth history surveys.

BACKGROUND: We assessed whether Demographic and Health Surveys (DHS), a large and high-quality source of under-5 mortality estimates in developing countries, would be able to detect reductions in under-5 mortality as established in global child health goals. METHODS AND RESULTS: Mortality estimates from 41 DHS conducted in African countries between 1986 and 2002, for the interval of 0-4 years preceding each survey (with a mean time lag of 2.5 years), were reviewed. The median relative error on national mortality rates was 4.4%. In multivariate regression, the relative error decreased with increasing sample size, increasing fertility rates, and increasing mortality rates. The error increased with the magnitude of the survey design effect, which resulted from cluster sampling. With levels of precision observed in previous surveys, reductions in all-cause under-5 mortality rates between two subsequent surveys of 15% or more would be detectable. The detection of smaller mortality reductions would require increases in sample size, from a current median of 7060 to over 20,000 women. Across the actual surveys conducted between 1986 and 2002, varying mortality trends were apparent at a national scale, but only around half of these were statistically significant. CONCLUSIONS: The interpretation of changes in under-5 mortality rates between subsequent surveys needs to take into account statistical significance. DHS birth history surveys with their present sampling design would be able to statistically confirm under-5 mortality reductions in African countries if true reductions were 15% or larger, and are highly relevant to tracking progress towards existing international child health targets.

Africa↗
PubMed2003

Do trichothecenes reduce viability of circulating blood cells and modify haemostasis parameters?

This manuscript describes the results of experiments conducted using human blood cells to determine the ability of T-2 toxin and DON to cause changes in clotting time, platelet aggregation, red blood cell haemolysis, RBC glucose content, lactate release, glutathione depletion, as well as white blood cell viability. In vitro results showed that haemostasis parameters and erythrocytes were not affected at concentrations able to induce inhibition of haematopoietic progenitor proliferation. In the presence of 10(-8) M and 10(-6) M T-2, the leucocyte number decreased at 24 h by 30% and 50% respectively. A 50% decrease in leucocyte number was observed for 10(-5) M DON. Results were compared with haematopoietic progenitor sensitivities. Due to the differences in sensitivities between mature blood cells and haematopoietic progenitors, haematological problems associated with trichothecene intoxication could be attributed to haematopoiesis inhibition.

Blood Glucose↗
PubMed2003

[Intrasurgical diagnostics in the case of suspected pancreatic cancer--the cytology].

A differentiated therapy of chronic pancreatitis and pancreatic carcinoma calls for evaluation of the validity of findings. Excisional biopsies, punch biopsies, and fine-needle aspiration cytology (FNAC) are the options available for intrasurgical confirmation. In 606 prospective cases intrasurgical fine-needle aspiration biopsy and cytological assessment were carried out. There were 330 cases of pancreatic carcinoma and 276 cases of benign diseases of pancreas included. The level of sensitivity is 92.4 %, specificity is 99.3 %, predictive value of positive results is 99.3 % and of negative results is 91.6 %. FNAC is a suitable method for confirmation of pancreatic carcinoma.

Biopsy, Needle↗
PubMed2003

[Late results after operative treatment of biliopancreatic cancer].

In this paper the late results after operative therapy of biliopancreatic carcinomas will be presented. Tumors of this region have many things in common. That's why we investigated the 4 tumor entities together. We studied the case histories of 434 patients treated between 1981 and 1997. We analysed the in- and outpatient data of the "Klinikum der Stadt Gera", documents of the tumor board and informations that were obtained from the ambulatory treating physicians. 283 patients suffered from pancreatic carcinoma, 50 from bile duct carcinoma, 60 from gallbladder carcinoma and 41 from carcinoma of the papilla Vateri. The survival rates after curative or palliative operative therapy of the 4 tumor entities were calculated according to Kaplan-Meier. The rate of curative operations and the 5-year-survival-rate after curative resection were 32.8% and 19.0%, resp. in pancreatic carcinoma, 28.0% and 49.0% in bile duct carcinoma, 26.7% and 50.0% in gallbladder carcinoma and 71.0% and 44.0% in carcinoma of the papilla Vateri. Due to the higher resection rate the overall results in patients with carcinoma of the papilla Vateri were much better than the results in the other analysed cancers. Up to now resection is the only way to cure the 4 entities of malignant tumors of the biliopancreatic region.

Age Factors↗
PubMed2002

Investigating a simple model of cutaneous wound healing angiogenesis.

A simple model of wound healing angiogenesis is presented, and investigated using numerical and asymptotic techniques. The model captures many key qualitative features of the wound healing angiogenic response, such as the propagation of a structural unit into the wound centre. A detailed perturbative study is pursued, and is shown to capture all features of the model. This enables one to show that the level of the angiogenic response predicted by the model is governed to a good approximation by a small number of parameter groupings. Further investigation leads to predictions concerning how one should select between potential optimal means of stimulating cell proliferation in order to increase the level of the angiogenic response.

Capillaries↗
PubMed1999

Chemical analysis of polar stratospheric cloud particles

A balloon-borne gondola carrying a particle analysis system, a backscatter sonde, and pressure and temperature sensors was launched from Kiruna, Sweden, on 25 January 1998. Measurements within polar stratospheric cloud layers inside the Arctic polar vortex show a close correlation between large backscatter ratios and enhanced particle-related water and nitric acid signals at low temperatures. Periodic structures in the data indicate the presence of lee waves. The H2O/HNO3 molar ratios are consistently found to be above 10 at atmospheric temperatures between 189 and 192 kelvin. Such high ratios indicate ternary solution particles of H2O, HNO3, and H2SO4 rather than the presence of solid hydrates.

Journal Article↗
PubMed1999

Cloning and sequencing of the central region of the flagellin gene from the Gram-positive bacterium Clostridium tyrobutyricum ATCC 25755.

The purpose of this study was to sequence the central part of the coding region of the Clostridium tyrobutyricum fiagellin gene to improve the immunoenzymatic counting of cells after milk filtration. The coding region was amplified by PCR, and the amplified products were cloned. A DNA sequence analysis of positive clones gave us 1,131 nucleotides with a partial calculated flagellin molecular mass of 40,143 Da. The flagellar filament protein sequence exhibited high levels of homology to sequences of flagellin protein from other bacteria in both N- and C-terminal parts, but little homology in the central domain. A PCR-restriction fragment length polymorphism analysis of amplified C. tyrobutyricum flagellin gene products confirmed the variability of the central domain. The flagellin mRNA was determined to be 1.1 kb in size, which suggests a monocistronic mRNA. Furthermore, the deduced protein flagellin contains eleven potential N-glycosylation sites and one sequence rich in serine, which could be modified by O-glycosylation.

Amino Acid Sequence↗
PubMed1998

Biodegradable positively charged ion exchange beads: a novel biomaterial for enhancing soft tissue repair.

Previous work in the area of vulnerary agents is extensive. One material of focus has been positively charged ion exchange beads, which have been shown to promote a variety of wound-healing responses in several models. The goal of this work was to improve upon the clinical utility of positively charged dextran beads by creating a biodegradable version that maintains the material's inherent efficacy. A chemical method consisting of a sodium periodate oxidation was used to create a degradable diethylaminoethanol crosslinked dextran bead. The ability of this process to create a degradable bead was verified in vitro and in vivo. Furthermore, efficacy was shown in a rat linear incision model for a variety of beads exhibiting different degradation rates. The results show that efficacy is maintained by a degradable bead, but there is a diminution of the magnitude of the response as the mass loss rate is increased. Efficacy also was investigated for a moderate but completely degrading bead material over time and dose. Wound breaking strength was evaluated at days 7, 10, 14, 21, and 28 for degradable beads at doses of 10 mg/mL and 50 mg/mL. Although little difference in efficacy was noted for the increased dose, statistically significant increases over control were seen at days 7, 10, and 14 for the 10 mg/mL dose and at days 10 and 14 for the 50 mg/mL dose. At days 21 and 28 there were no differences between treated and control wounds.

Animals↗
PubMed1998

Health risks.

The health risks associated with ozone depletion will principally be those due to increased ultraviolet B (UV-B) radiation in the environment, i.e., increased damage to the eyes, the immune system, and the skin. Some new risks may also be introduced with the increased use of alternatives to the ozone-depleting substances (ODSs). Quantitative risk estimates are available for some of the UV-B-associated effects, e.g., cataract and skin cancer; however, the data are insufficient to develop similar estimates for effects such as immunosuppression and the toxicity of alternatives. Ocular damage from UV exposures includes effects on the cornea, lens, iris, and associated epithelial and conjunctival tissues. The most common acute ocular effect of environmental ultraviolet radiation (UVR) is photokeratitis. Also known as snowblindness in skiers, this condition also occurs in other outdoor recreationists. Chronic eye conditions likely to increase with ozone depletion include cataract, squamous cell carcinoma, ocular melanoma, and a variety of corneal/conjunctival effects, e.g., pterygium and pinguecula. Suppression of local (at the site of UV exposure) and systemic (at a distant, unexposed site) immune responses to a variety of antigens has been demonstrated in both humans and animals exposed to UV-B. In experiments with animals these effects have been shown to worsen the course/outcome of some infectious diseases and cancers. There is reasonably good evidence that such immunosuppression plays a role in human carcinogenesis; however, the implications of such immunosuppression for human infectious diseases are still unknown. In light-skinned populations, exposure to solar UVR appears to be the most important environmental risk factor for basal and squamous cell carcinomas and cutaneous melanoma. Originally it was believed that total accumulated exposure to UVR was the most important environmental factor in determining risk for these tumors. Recent information now suggests that only squamous cell carcinoma risk is related to total exposure. In the cases of both basal cell carcinoma and melanoma, new information suggests that increases in risk are tied to early exposures (before about age 15), particularly those leading to severe sunburns. Testing of a number of the chlorofluorocarbon (CFC) alternatives indicates that most of these chemicals have low acute toxicity, and low to moderate chronic toxicity. Some chemicals that were originally proposed as alternatives have been dropped from consideration because these tests raised concerns about toxicity and/or manufacturing difficulties. In one instance, high accidental occupational exposure was associated with liver damage, underlining the need for care in the use of these substitutes. Recent quantitative risk estimates have been developed for cataract, melanoma, and all skin cancers combined. These estimates indicate that under the Montreal Adjustments, cataract and skin-cancer incidence will peak mid-century at additional incidences of just under 3 per 100,000 and about 7 per 100,000, respectively.

Animals↗
PubMed1998

Biochemical and immunological analyses of the flagellin of Clostridium tyrobutyricum ATCC 25755.

The monoclonal antibody 21E7-B12 (IgG3) can be used in a direct method of Clostridium tyrobutyricum detection based on an immunoenzymatic assay. Immunoelectron microscopy demonstrated that the 21E7-B12 antibody recognized the surface-exposed epitopes on the flagellar filaments of C. tyrobutyricum. After flagellar extraction, the purified flagellin showed an apparent molecular mass of 46 kDa with an isoelectric point of 3.6. Sugar staining, mild periodate oxidation and beta-elimination experiments showed that the flagellin was glycosylated and that the 21E7-B12 epitope was located in the sugar moiety. Amino acid composition showed that the flagellar filament protein contained a high percentage of serine and threonine, while proline was absent. The first 23 residues of the N-terminal were determined and sequence homology with other flagellins was found.

Amino Acid Sequence↗
PubMed1998

Partial analysis of the flagellar antigenic determinant recognized by a monoclonal antibody to Clostridium tyrobutyricum.

In order to count Clostridium tyrobutyricum spores in milk after membrane filtration, murine 21E7-B12 monoclonal antibody was produced. Elution of the monoclonal antibody from this antigen, the flagellar filament protein, by carbohydrate ligands was used to study the epitope structure. A competitive elution of an anti-dextran monoclonal antibody by carbohydrate ligands served as a control in order to validate the immunological tool applied to flagellin epitope study. The carbohydrate moiety of flagellin contained D-glucose and N-acetyl-glucosamine in a molar ration of 11:1 as determined by gas-liquid chromatography and 2 low-abundancy unidentified compounds. In ELISA, D-glucose and N-acetyl-glucosamine did not dissociate the antibody-flagellin complex contrary to maltose, maltotriose, maltotetraose and maltopentaose. The efficiency of elution increased from the dimer to the pentamer and became nil for maltohexaose and maltoheptaose. The fact that the hexamer and heptamer could not react with the 21E7-B12 monoclonal antibody could be explained by a drastic conformational change. The over-all stretched maltopentaose switch to a helical-shaped maltoheptaose which could not fit the 21E7-B12 monoclonal antibody antigen-combining site. Thus, flagellin epitope may contain alpha (1-->4) linked glucose residues plus either N-actyl-glucosamine or an unidentified compound that maintain it in an extended shape.

Antibodies, Monoclonal↗
PubMed1998

[The effect of ultrapure hyaluronic acid with different molecular weights on the healing of porcine full thickness skin wound].

Hyaluronic acid (HA) is an extracellular matrix having a high molecular weight. This study is to investigate (1) whether the ultrapure HA had effect on the healing of full thickness skin wounds in animals, and (2) the relation between the effect of HA and the size of the molecular weight of HA. The ultrapure HA with different molecular weights and HA with intermediate molecular weight were applied topically to the wounds from removal of full thickness of skin and topical application of normal saline was used as control. At 21st, day after the topical application, the tensile strength was reduced in wounds of groups of HA with high and intermediate molecular weights, but not in the group of low molecular weight. Using laser-Doppler scanning of the dynamic changes of the wound perfusion, in the 3rd day the blood supply to the wound was reduced in HA groups of high and intermediate molecular weights, but at the 7th day, the blood supply of all wounds in the two groups was increased. The study revealed that HA with different molecular weights had different actions on the contraction of wounds, the angiogenesis of the granulation tissues and the healing strength of the wounds. It was indicated that hyaluronan could be used for wound treatment or as a carrier, but its accurate composition must be carefully noted.

Animals↗