Content of Asthmagen Natural Rubber Latex Allergens in Commercial Disposable Gloves.

The use of natural rubber latex (NRL) gloves in many occupations may lead to latex sensitization, allergic asthma, and skin reactions. Due to their good properties and environmental safety NRL gloves are still being used in the healthcare setting, but also in the food industry, by hairdressers, cleaners, etc. The aim of our study was to assess the protein and NRL allergen content in commercial gloves by different methods, including a new assay. Twenty commercially available NRL gloves were analyzed. Protein extraction was performed according to the international standard ASTM D-5712. Total protein content was measured with a modified Lowry method, NRL content with the CAP Inhibition Assay, the Beezhold ELISA Inhibition Assay, and an innovative ELISA with IgY-antibodies extracted from eggs of NRL-immunized hens (IgY Inhibition Assay). We found a high protein content in a range of 215.0-1304.7 µg/g in 8 out of the 20 NRL gloves. Seven of the 20 gloves were powdered, four of them with a high protein content. In gloves with high protein content, the immunological tests detected congruently high levels of NRL allergen. We conclude that a high percentage of commercially available NRL gloves still represent a risk for NRL allergy, including asthma. The modified Lowry Method allows to infer on the latex allergen content.

IgE Reactivity, Work Related Allergic Symptoms, Asthma Severity, and Quality of Life in Bakers with Occupational Asthma.

In Germany, bakers with occupational asthma willing to stay in their job are included in an interdisciplinary program of the Social Accident Insurance for Foodstuff and Catering Industry (BGN). The primary aim is to reduce flour dust exposure, and to provide adequate medical treatment. Our aim was to evaluate the program's effect on the disease's course using routinely collected data. Forty three bakers with allergic occupational asthma and with the available baseline level of IgE (f4, f5) were investigated. Changes in IgE related to wheat and rye flour exposure were measured by ImmunoCAP test during follow-up visits. A questionnaire on work-related allergic complaints (WRAC), the Asthma Control Test (ACT), a 10-point scale of asthma severity grade, and quality of life instruments (EQ-5D-5L, Mini-AQLQ) were administered. We found an improvement of asthma severity in 88.4 % of the bakers. WRAC were reported by 65 %; 77 % had good asthma control (ACT ≥ 20); and 81 % had regular asthma medication. A relevant reduction of ≥2 CAP-classes for both allergens was seen in 12 % of the subjects. Health-related and asthma-specific quality of life was high. We conclude that satisfactory asthma control is probably the result of adequate medical management. In a subgroup of bakers with decreased specific IgE, it may also be attributed to reduced allergen exposure.

Content of Asthmagen Natural Rubber Latex Allergens in Commercial Disposable Gloves.

The use of natural rubber latex (NRL) gloves in many occupations may lead to latex sensitization, allergic asthma, and skin reactions. Due to their good properties and environmental safety NRL gloves are still being used in the healthcare setting, but also in the food industry, by hairdressers, cleaners, etc. The aim of our study was to assess the protein and NRL allergen content in commercial gloves by different methods, including a new assay. Twenty commercially available NRL gloves were analyzed. Protein extraction was performed according to the international standard ASTM D-5712. Total protein content was measured with a modified Lowry method, NRL content with the CAP Inhibition Assay, the Beezhold ELISA Inhibition Assay, and an innovative ELISA with IgY-antibodies extracted from eggs of NRL-immunized hens (IgY Inhibition Assay). We found a high protein content in a range of 215.0-1304.7 µg/g in 8 out of the 20 NRL gloves. Seven of the 20 gloves were powdered, four of them with a high protein content. In gloves with high protein content, the immunological tests detected congruently high levels of NRL allergen. We conclude that a high percentage of commercially available NRL gloves still represent a risk for NRL allergy, including asthma. The modified Lowry Method allows to infer on the latex allergen content.

Gradual versus continuous increase of load in ergometric tests: are the results comparable?

Standard exercise testing (ET) comprises progressive exercise provocation with cardiovascular monitoring. Exercise tolerance is estimated by workload. Cardiopulmonary exercise testing (CPX) is a non-invasive measurement of ventilatory gas exchange which provides more accurate quantifications of cardiorespiratory fitness (CRF). Workload is usually increased stepwise in ET and continuously (ramp) in CPX. Our aim was to examine the comparability of the results. Thirty two healthy volunteers (17 females/15 males, age 26.8±6.1 years, BMI 24.5±3.0) underwent exercise testing on a bicycle ergometer up to maximum physical exhaustion; under ramp protocol (CPX) and 2-7 days later with a stepwise increase of workload (ET). We compared the physical work capacity under both methods at maximum workload, at heart rate of 150 and 170 beats/min (PWC150 and PWC170), and the exercise duration. We found that there were no statistically significant differences in the maximum heart rate (CPX: 177.1±11.7/min vs. ET: 178.5±11.2/min) or maximal workload (CPX: 219.8±50.6 vs. ET: 209.4±42.5). PWC150 and PWC150/kg were higher with CPX than those with ET (156.6±51 vs. 146.4±42.3, p<0.001 and 2.1±0.5 vs. 1.9±0.4, respectively, p<0.001). Exercise duration was almost equal (12.1 vs. 11.3 min). We conclude that overall physical performance was higher with CPX. Since the results are similar, we recommend the CPX: wattage and other parameters in performance assessment are to be determined directly, interpolations are obsolete.

Occupational obstructive airway diseases caused by the natural gas odorant tetrahydrothiophene--two case reports.

BACKGROUND: Tetrahydrothiophene (THT) is frequently used to odorize natural (city) gas. Only sparse data on adverse health effects of THT on humans are available. METHODS: We performed a literature search and clinical investigations including case history and cardiopulmonary diagnostic tests in two symptomatic THT-exposed outpatients. RESULTS: The two THT-exposed city workers developed transient neurologic symptoms such as nausea, vomiting, headaches, as well as skin and mucosa irritation, chronic rhinitis, chronic obstructive pulmonary disease, arterial hypertension, and cardiac arrhythmia. The neurological symptoms and respiratory disorders were found to be caused by intermittently high THT exposures. In favor of a causal relationship were severe work-related neurological and respiratory symptoms in previously healthy workers, results of animal experiments, and another report with very similar findings in the literature. The etiology of arterial hypertension and cardiac arrhythmia, however, remains unclear. CONCLUSIONS: Our two case reports demonstrate that repeated high THT-exposures can--in addition to neurotoxic symptoms--elicit chronic obstructive pulmonary disease. We recommend improved primary and secondary preventive measures, including the establishment of a TLV.

Evaluation of ractopamine hydrochloride (Optaflexx) on growth performance and carcass characteristics of finishing steers across different feeding durations.

Two experiments were conducted to evaluate the effects of ractopamine hydrochloride (RAC) dose and duration on growth performance and carcass characteristics of finishing steers. In Exp. 1, 336 crossbred steers (initial BW of RAC feeding = 539 kg [SD 22]) were used in a 2 × 2 factorial arrangement of treatments with one factor being RAC dose (0 or 200 mg/steer daily) and the other factor being RAC duration (28 or 42 d prior to harvest). There were no RAC dose × duration interactions ( ≥ 0.08) for growth performance or carcass characteristics. Feeding 200 mg RAC/steer daily increased ( < 0.01) live final BW by 9.0 kg compared with steers not fed RAC. Carcass-adjusted final BW, ADG, and G:F were greater ( < 0.01) for steers fed 200 mg RAC/d compared with steers not fed RAC. Hot carcass weight was 4.7 kg heavier ( < 0.01) for steers fed 200 mg RAC/d compared with steers not fed RAC. In Exp. 2, crossbred steers ( = 576; experiment initial BW = 408 kg [SD 29]) were used in a randomized block design with a 3 × 3 factorial arrangement of treatments. Factors included RAC dose (0, 300, and 400 mg/steer daily) and RAC duration (14, 28, or 42 d prior to harvest). There was a tendency ( ≤ 0.08) for an interaction of RAC dose × duration for final live BW, DMI, and live G:F; therefore, simple effects are presented. At 28 d, live final BW for steers fed 400 mg RAC/d were heavier ( < 0.01) than for steers fed 0 mg RAC/d. There was a tendency at 28 d for increased live final BW for steers fed RAC at 300 mg/d ( = 0.08) compared with steers fed RAC at 0 mg and for steers fed 400 mg RAC/d compared with steers fed 300 mg RAC/d ( = 0.06). Live final BW was greater ( < 0.01) for steers fed RAC for 42 d at 300 and 400 mg/d compared with steers fed 0 mg; however, live final BW was similar ( = 0.48) between steers fed 300 and 400 mg RAC/d. Despite no RAC dose × duration interaction ( = 0.30) for HCW, simple effects will be presented for consistency. Hot carcass weight was greater for steers fed 300 and 400 mg RAC/d for 28 and 42 d compared with steers fed 0 mg at 28 ( ≤ 0.02) and 42 d ( < 0.01). Feeding 300 mg RAC/d for 28 or 42 d increased HCW by 5.1 and 7.6 kg, respectively, compared with steers fed 0 mg RAC. Additionally, feeding 400 mg RAC/d for 28 or 42 d resulted in increases of 8.9 and 9.4 kg, respectively, in HCW compared with steers fed 0 mg RAC. In conclusion, our results confirm that feeding RAC improves growth performance and carcass weight, with an optimal duration of feeding RAC being 28 d.

Cytogenetic characteristics of a murine in vitro model for the human anaplastic large cell lymphoma (ALCL).

Anaplastic large cell lymphoma (ALCL) is an entity of non-Hodgkin lymphomas (NHL) that often occurs in young children and adolescents. In the majority of cases, ALCL are of T-cell origin and contain the t(2;5)(p23;q35) leading to an NPM-ALK fusion or variant ALK translocations. In addition, there is an ALK-negative subtype of ALCL. The anaplastic lymphoid cell line TS1G6 established by interleukin (IL)-9 transfection of T-helper cells represents a murine model of this subtype. Here, we describe the cytogenetic features of this cell line using spectral karyotyping (SKY) and single-color fluorescence in situ hybridization (FISH). We show that TS1G6 cells exhibit a hypotetraploid karyotype with complex structural alterations. Several unbalanced translocations involved the chromosomal region 14E5, and different translocation partners, i.e. X?A6, 3A3 and 8A1. FISH analysis using a BAC clone containing c-myc confirmed the presence of six copies, but also demonstrated that two loci were irregularly located, indicating that additional intrachromosomal rearrangements had occurred. Moreover, a duplication of the region XF2 approximately 3 was identified. Furthermore, six chromosomes 15 were found, representing a trisomy 15 in a tetraploid chromosome complement, indicating an altered gene dosage of the oncogene c-myc located in region 15D3.

Effects of processing treated corn stover and distillers' grains on performance and total tract digestion of finishing cattle.

Two studies evaluated effects of replacing corn with a pellet containing alkaline treated corn stover, dried distillers' grains plus solubles (DDGS), and distillers' solubles on total tract digestion and performance of finishing cattle. Experiment 1 used 4 ruminally fistulated steers in a 4 × 6 Latin rectangle to evaluate total tract digestion. Treatments consisted of a control (CON) containing 50.3% dry-rolled corn (DRC), 40% modified distillers' grains plus solubles (MDGS), and 5% untreated corn stover. The next 2 treatments replaced 25% DRC (DM basis) with either a CaO-treated stover pellet (STOVPEL) or a pellet consisting of 64% CaO-treated corn stover, 18% DDGS, and 18% corn distillers' solubles (COMBPEL). The last treatment replaced 25% DRC with a mixture of feeds: 10% treated stover pellet, 10% DDGS, and 5% distillers' solubles (COMB). Experiment 2 used 336 crossbred steer calves (301 ± 25 kg initial BW) in a 2 × 3 + 1 factorial to evaluate effects of replacing corn with a pellet containing 64% CaO-treated corn stover, 18% DDGS, and 18% corn distillers' solubles on finishing performance. Factors included level of MDGS (20 or 40%) and pellet inclusion (10, 20, or 30%). The CON diet contained a 50:50 blend of DRC and high-moisture corn and 40% MDGS. All diets contained 5% wheat straw and 4% dry meal supplement. In Exp. 1, no differences ( ≥ 0.50) were observed between the CON, STOVPEL, COMB, or COMBPEL treatments for DM (76.5, 75.4, 72.5, and 78.0%, respectively; SEM 2.5) or OM (79.1, 79.7, 75.7, and 80.5%, respectively; SEM 2.4) digestibility. In Exp. 2, a linear increase ( = 0.03) in DMI was observed as pellet inclusion increased from 0% in the CON (10.6 kg/d [SE 0.13]) to 30% (11.0 kg/d [SE 0.13]) in treatments containing 40% MDGS. A quadratic response ( = 0.03) in DMI was observed as pellet inclusion increased in diets containing 20% MDGS due to greater DMI of the 20% pellet treatment. A linear decrease ( = 0.03) in G:F was observed as the level of pellet inclusion increased from 0 (0.182 [SE 0.02]) to 30% (0.175 [SE 0.02]) in diets containing 40% MDGS. In diets containing 20% MDGS, no differences ( ≥ 0.22) in G:F were observed as pellet inclusion increased from 10 to 30%. In conclusion, replacing up to 20% of corn (DM basis) in diets containing 20% MDGS had minimal impact on performance. Conversely, up to 30% of corn could be replaced in diets containing 40% MDGS with little impact on performance.

Effect of ractopamine hydrochloride (Optaflexx) dose and duration on growth performance and carcass characteristics of finishing steers.

Three experiments evaluated the effects of ractopamine hydrochloride (RAC) dose and duration on growth performance and carcass characteristics of feedlot steers. In total, 1,509 crossbred steers (530 kg initial BW [SD 22]) were used in a randomized complete block design using a 3 × 3 factorial treatment structure. Treatments consisted of RAC dose (0, 100, or 200 mg/steer daily) and duration (28, 35, or 42 d) of RAC feeding prior to harvest. Initiation of RAC dose was staggered (7 d apart) based on RAC duration, which resulted in common days on feed among treatments. Data from the 3 experiments were combined for statistical analyses. There were no RAC dose × duration interactions ( ≥ 0.85) for growth performance. Live final BW was not different ( ≥ 0.24) as RAC dose increased. Dry matter intake linearly decreased ( < 0.01) as RAC dose increased. Live ADG and G:F linearly increased ( ≤ 0.01) as RAC dose increased. Carcass-adjusted ADG and G:F linearly increased ( ≤ 0.02) as RAC dose increased. Compared with steers fed 0 mg RAC/steer daily, G:F was improved by 5.0 and 13.0% when steers were fed 100 ( = 0.31) and 200 ( = 0.01) mg RAC/steer daily, respectively. Hot carcass weight tended ( = 0.10) to linearly increase as RAC dose increased, with carcasses from steers fed 100 ( = 0.38) and 200 ( = 0.10) mg RAC/steer daily being 2.2 and 4.1 kg heavier, respectively, than carcasses from steers fed 0 mg RAC/steer daily. Increasing RAC dose linearly ( < 0.01) increased LM area and linearly ( = 0.02) decreased marbling score. Live final BW was not different ( ≥ 0.60) among RAC durations. Carcass-adjusted final BW, ADG, and G:F were not different ( ≥ 0.41) as RAC duration increased. Carcass traits did not differ ( ≥ 0.18) among RAC duration. Feeding 200 mg RAC/steer daily improved ADG, feed efficiency, and HCW. Increasing the feeding duration of RAC had no effect of growth performance or carcass characteristics. These data indicate that feeding 200 mg RAC/steer daily for 28 d improves steer growth performance.

A cytosolic source of calcium unveiled by hydrogen peroxide with relevance for epithelial cell death.

Oxidative stress releases intracellular calcium, which plays a pathogenic role in mammalian cell death. Here we report a search for the source of oxidative calcium in HeLa cells based on confocal epifluorescence microscopy. H(2)O(2) caused a rapid increase in cytosolic calcium, which was followed by mitochondrial Ca(2+) loading. Combined mitochondrial uncoupling with full depletion of thapsigargin-sensitive stores abrogated inositol 1,4,5-trisphosphate-mediated calcium release but failed to inhibit H(2)O(2)-induced calcium release, observation that was confirmed in MDCK cells. Prevention of peroxide-induced acidification with a pH clamp was also ineffective, discarding a role for endosomal/lysosomal Ca(2+)/H(+) exchange. Lysosomal integrity was not affected by H(2)O(2). Mature human erythrocytes also reacted to peroxide by releasing intracellular calcium, thus directly demonstrating the cytosolic source. Glutathione depletion markedly sensitized cells to H(2)O(2), an effect opposite to that achieved by DTT. Iron chelation was ineffective. In summary, our results show the existence of a previously unrecognized sulfhydryl-sensitive source of pathogenic calcium in the cytosol of mammalian cells.

Apoptotic and necrotic blebs in epithelial cells display similar neck diameters but different kinase dependency.

Apoptotic and necrotic blebs elicited by H(2)O(2) were compared in terms of dynamics, structure and underlying biochemistry in HeLa cells and Clone 9 cells. Apoptotic blebs appeared in a few minutes and required micromolar peroxide concentrations. Necrotic blebs appeared much later, prior to cell permeabilization, and required millimolar peroxide concentrations. Strikingly, necrotic blebs grew at a constant rate, which was unaffected throughout successive cycles of budding and detachment. At 1 microm diameter, the necks of necrotic and apoptotic blebs were almost identical. ATP depletion was discarded as a major factor for both types of bleb. Inhibition of ROCK-I, MLCK and p38MAPK strongly decreased apoptotic blebbing but had no effect on necrotic blebbing. Taken together, these data suggest the existence of a novel structure of fixed dimensions at the neck of both types of plasma membrane blebs in epithelial cells. However, necrotic blebs can be distinguished from apoptotic blebs in their susceptibility to actomyosin kinase inhibition.

Antagonism of platelet activating factor-induced chemiluminescence in guinea-pig peritoneal macrophages in differing states of activation.

1. The effects of the platelet activating factor (Paf) antagonists alprazolam, BN 52021, kadsurenone, L 652,731 and SRI 63119 have been studied on Paf-induced chemiluminescence (CL) of guinea-pig, C. parvum-activated peritoneal macrophages in vitro. 2. All antagonists produced a shift to the right in the dose-response curve to Paf (0.001-10 mumol l-1). Schild plots for BN 52021, L 652,731, kadsurenone and SRI 63119 were linear, but only for BN 52021 and kadsurenone did the mean slope not differ significantly from unity. Mean pA2 values for BN 52021 and kadsurenone were 6.60 +/- 0.05 and 6.41 +/- 0.14 (mean + s.e.mean) respectively. Calculation of IC50 values for all antagonists (at 0.1 mumol l-1 Paf) gave an order of potency: L 652731 greater than kadsurenone greater than or equal to BN 52021 greater than alprazolam greater than SRI 63119. 3. When individual pA2 values for BN 52021 and kadsurenone were plotted against the maximal CL response to Paf of cell suspensions in the absence of antagonist (reflecting the degree of activation of the macrophages by the C. parvum), it was found that the affinity of both antagonists for macrophage Paf receptors remained relatively constant irrespective of the activation state of the cells. 4. We conclude that activation of guinea-pig peritoneal macrophages does not account for the increased affinity for macrophage Paf receptors previously observed for kadsurenone. Kadsurenone and BN 52021 presumably bind to a site on Paf receptors which is not affected by the activation process, while alprazolam and SRI 63119 are non-specific antagonists. The reason for the difference between the competitive nature of kadsurenone and its structural analogue L 652,731 is unclear.

A preclinical model for experimental chemotherapy of human head and neck cancer.

We developed a mouse model in a representative human derived head and neck cancer cell line for preclinical studies to evaluate antitumor response, tumor-free survival and host toxicity of alkylating agents, antimetabolites, platinum analogs and taxanes alone or in combination. Ninety athymic NMRI mice were inoculated with human derived oral squamous cell carcinoma cells growing on the hind paw to an average volume of 180 +/- 80 mm3. Animals were stratified according to tumor volume into 10 groups (n=6-10) and treated with ifosfamide (65 mg/kg b.w.), docetaxel (24 mg/kg b.w.), cisplatin (2 mg/kg b.w.), carboplatin (6 or 10 mg/kg b.w.), methotrexate (1 mg/kg b.w.), and fluorouracil (15 mg/kg b.w.) intravenously in single agent or combination (ifosfamide plus docetaxel or ifosfamide plus carboplatin) treatment schedules or controls. Tumor volume was measured 3 times per week for 60 days. The average tumor volume, the overall survival time and the response rates (CR, PR) of the treated animals were compared with the data obtained from untreated controls and statistically evaluated. Untreated tumors showed rapid and exponential tumor growth. Single agent therapies with ifosfamide, cisplatinum, and docetaxel lead to significant tumor regression and improved overall survival. Low dose carboplatin monotherapy induced significant tumor growth delay, but not significant tumor regression. Most impressive tumor-free survival was achieved by combination treatment with ifosfamide and docetaxel. This preclinical study demonstrates an animal model capable of differentiating various chemotherapy regimens.

Single-dose toxicity study of hepatic intra-arterial infusion of doxorubicin coupled to a novel magnetically targeted drug carrier.

The toxicity of a single hepatic intra-arterial administration of doxorubicin (DOX) coupled to a magnetically targeted drug carrier (MTC) was evaluated in a swine model. MTC is a microparticle composite of elemental iron and activated carbon. MTC-DOX is a new formulation of doxorubicin absorbed to the MTC and is designed for site-specific delivery to a solid tumor in the presence of an externally applied magnetic field. The magnetic field induces extravasation of MTCs through the vascular wall, leading to localization and retention in the tissue at the targeted site. Eighteen swine were assigned to 6 treatment groups, including 3 control groups (vehicle control, doxorubicin, MTC), and 3 experimental groups that received the MTC-DOX preparation. Animals were given a single administration of test article, evaluated over 28 days, and then sacrificed. Signs of toxicity were monitored via clinical status, total body weight, gross and microscopic pathology, and serum chemistries. Angiography was used to determine the extent of any embolization present. There were no adverse effects observed in the DOX-alone group. Biologically significant, treatment-related gross and microscopic lesions were limited to the targeted area of the liver only in groups receiving > or =75 mg of MTC (with or without doxorubicin). The severity of liver necrosis correlated to the severity of embolization following treatment. Doxorubicin was not freely circulating in any of the MTC-DOX groups, suggesting successful localization to the targeted site. The no-adverse-effect level (NOAEL) was determined to be the MTC-DOX low-dose group.

Fine needle aspiration cytology of the pancreas. A retrospective study of 73 cases.

Retrospective review of pancreatic fine needle aspiration (FNA) biopsy specimens collected with computed tomographic guidance from 73 patients between 1980 and 1985 at the Medical Center of Delaware was performed to determine the accuracy of the procedure in our hands and to identify possible problem areas for cytologic diagnosis. When compared with clinical data or tissue diagnosis, FNA had a sensitivity for the detection of pancreatic carcinoma of 67.7%. The predictive value of a negative result was only 23.1%. When compared to the cytologic diagnosis made at the time of review, FNA had a sensitivity of 100%, but a single false-positive case was identified. In addition to the majority of probable pancreatic ductal carcinomas, a hepatoma and a lymphoma were detected. Cases of primary pancreatic carcinoma were classified by cytologic features, but all groups had dismal three-to-six-month median survivals, regardless of the degree of tumor differentiation. Survival times were similarly low for patients with negative pancreatic FNAs. The low patient survival times, regardless of FNA diagnosis, support the value of avoiding laparotomy in these patients and confirm the high false-negative rate of the procedure.

[Coping strategies of adolescents and their significance for counseling]. / Bewältigungsstrategien von Jugendlichen und ihre Bedeutung für die Beratung.

This study investigated the problem solving strategies in adolescents. An anonymous, open questionnaire was employed. The descriptive analysis of the results show that personal discussion on the pertinent problems is the most common strategy, whereas other methods for overcoming problems (groups, institutions, financial and social aid etc.) are underrepresented. Approximately 1/6 of the adolescents are unable to comment on ways of solving problems specific to their age-group. Moreover, it is striking that only ca. 20% of the adolescents have realistic knowledge about the working methods of the respective institutions. The statistical analysis differentiates these effects according to the variables sex, age, and education. In the concluding section the consequences for institutional youth counselling are discussed. It is emphasized that ideas about counselling possibilities should become more realistic. In addition, the combination of social and psychotherapeutic interventions is suggested.

Facial morphology and malocclusions.

The aim of this study was to determine whether sagittal and vertical aberrations in intermaxillary incisal tooth and jaw relationships were reflected in facial morphology. One hundred seventy-two children (79 girls and 93 boys), 12 to 14 years of age, were selected from the Orthodontic Department, University of Giessen. Pretreatment profile and frontal facial photographs as well as profile roentgenograms in centric occlusion for each child were made. The method consisted of (1) a personal appraisal of the existing incisal tooth and jaw relationship by visual inspection of facial photographs, (2) a validity assessment of these personal appraisals, and (3) a comparison of linear and angular measurements made from facial photographs and from lateral headfilms. The result of this investigation revealed that a large overjet and a Class II, Division 2 incisal tooth relationship were most often reflected in the face. A Class III incisal tooth relationship and an open bite, however, were difficult to detect. Sagittal maxillary and mandibular positions could only occasionally be determined on the basis of facial appearance, while a Class II jaw base relationship (large ANB angle) could easily be seen. The vertical jaw relationship (mandibular plane angle and anterior facial height index) could be determined with relatively high precision. When the measurements from the facial photographs were compared with those from the lateral headfilms, moderate to high correlations were found between skeletal and soft tissue readings: ANB angle (r = +0.63), mandibular plane angle (r = +0.93), and anterior facial height index (r = +0.86). It was concluded that sagittal and vertical dental and skeletal intermaxillary malrelationships were only partly reflected in the face.

In situ microscopy for on-line determination of biomass.

A sensor is presented, which allows on-line microscopic observation of microorganisms during fermentations in bioreactors. This sensor, an In Situ Microscope (ISM) consists of a direct-light microscope with a measuring chamber, integrated in a 25 mm stainless steel tube, two CCD-cameras, and two frame-grabbers. The data obtained are processed by an automatic image analysis system. The ISM is connected with the bioreactor via a standard port, and it is immersed directly in the culture liquid-in our case Saccharomyces cerevisiae in a synthetic medium. The microscopic examination of the liquid is performed in the measuring chamber, which is situated near the front end of the sensor head. The measuring chamber is opened and closed periodically. In the open state, the liquid in the bioreactor flows unrestricted through the chamber. In closing, a defined volume of 2,2. 10(-8) mL of the liquid becomes enclosed. After a few seconds, when the movement of the cells in the enclosed culture has stopped, they are examined with the microscope. The microscopic images of the cells are registered with the CCD-cameras and are visualized on a monitor, allowing a direct view of the cell population. After detection, the measuring chamber reopens, and the enclosed liquid is released. The images obtained are evaluated as to cell concentration, cell size, cell volume, biomass, and other relevant parameters simultaneously by automatic image analysis. With a PC (486/33 MHz), image processing takes about 15 s per image. The detection range tested when measuring cells of S. cerevisiae is about 10(6) to 10(9) cells/mL (equivalent to a biomass of 0.01 g/L to 12 g/L). The calculated biomass values correlate very well with those obtained using dry weight analysis. Furthermore, histograms can be calculated, which are comparable to those obtained by flow cytometry.