Chemosensory control of pollen ingestion in the hoverfly Eristalis tenax by labellar taste hairs

The labellar gustatory system of the dronefly Eristalis tenax L. (Syrphidae; Diptera) that enables the fly to discriminate between pollen and nectar is investigated, and the triggering of pollen ingestion is examined. In behavioural preference tests, exhaustively extracted pollen of the sunflower Helianthus annuus is consumed in smaller amounts than untreated pollen, indicating that water-soluble substances are important for acceptance. Dry pollen is preferred over moist pollen in which the grains stick together, suggesting that mechanical properties of the pollen also play a role in its sensory assessment. Electrophysiological studies of the labellar taste hairs reveal that aqueous extracts of pollen (2% w/v) stimulate the salt receptor cell, but not the sugar receptor cell. The response of the water receptor cell remains the same as to pure water (or standard electrolyte, 10 mmol.l-1 KCl). Of the 20 amino acids tested, the salt cell is sensitive only to proline in a submillimolar range. Behavioural experiments support the electrophysiological findings. When KCl is applied at concentrations eliciting salt-cell spike frequencies equal to those produced by pollen extract (which is often accepted), the water receptor cell is inhibited and a pronounced rejection behaviour occurs. This rejection of concentrated salt solution in Eristalis is therefore mainly mediated by the inhibition of the water cell.

Effect of branch frequency in Aspergillus oryzae on protein secretion and culture viscosity

Highly branched mutants of two strains of Aspergillus oryzae (IFO4177, which produces alpha-amylase, and a transformant of IFO4177 [AMG#13], which produces heterologous glucoamylase in addition to alpha-amylase) were generated by UV or nitrous acid mutagenesis. Four mutants of the parental strain (IFO4177), which were 10 to 50% more branched than the parental strain, were studied in stirred batch culture and no differences were observed in either the amount or the rate of enzyme production. Five mutants of the transformed parental strain (AMG#13), which were 20 to 58% more branched than the parental strain, were studied in either batch, fed-batch or continuous culture. In batch culture, three of the mutants produced more glucoamylase than the transformed parental strain, although only two mutants produced more glucoamylase and alpha-amylase combined. No increase in enzyme production was observed in either chemostat or fed-batch culture. Cultures of highly branched mutants were less viscous than those of the parental and transformed parental strains. A linear relationship was found between the degree of branching (measured as hyphal growth unit length) and culture viscosity (measured as the torque exerted on the rheometer impeller) for these strains. DOT-controlled fed-batch cultures (in which the medium feed rate was determined by the DOT) were thus inoculated with either the transformed parent or highly branched mutants of the transformed parent to determine whether the reduced viscosity would improve aeration and give higher enzyme yields. The average rate of medium addition was higher for the two highly branched mutants (ca. 8.3 g medium h(-1)) than for the parental strain (5.7 g medium h(-1)). Specific enzyme production in the DOT controlled fed-batch cultures was similar for all three strains (approx. 0.24 g alpha-amylase and glucoamylase [g of biomass](-1)), but one of the highly branched mutants made more total enzyme (24.3 +/- 0.2 g alpha-amylase and glucoamylase) than the parental strain (21.7 +/- 0.4 g alpha-amylase and glucoamylase).

Inhibitors present in blood do not inhibit PCR from buccal cell preparations: case report

BACKGROUND

Hemochromatosis is a common disease that is characterized by high ferritin levels and/or high iron saturation and mutations in two alleles.

MATERIAL AND METHODS

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) is often performed on DNA extracted from blood since blood yields high concentrations of DNA. However, inhibitors can cause PCR failure in DNA extracted from blood thus preventing a molecular diagnosis.

RESULTS

This report describes a case where multiple blood draws resulted in unamplifiable DNA. Subsequently, a buccal cell sample was collected and extracted. DNA extracted from the buccal cells yielded amplifiable DNA in contrast to DNA extracted from the patient's blood. In addition, the patient was identified as having a homozygous mutation for one allele of the hemochromatosis gene.

CONCLUSION

These results suggests that a buccal cell DNA extraction may be useful in cases where blood samples contain inhibitory substances for PCR.

Upper trapezius muscle activity patterns during repetitive manual material handling and work with with a computer mouse

Firstly, upper trapezius EMG activity patterns were recorded on the dominant side of 6 industrial production workers and on the side operating a computer mouse of 14 computer-aided design (CAD) operators to study differences in acute muscular response related to the repetitiveness of the exposure. The work tasks were performed with median arm movement frequencies ranging from 5 min(-1) to 13 min(-1) and were characterized by work cycle times ranging from less than 30 sec to several days. However, the static and median EMG levels and EMG gap frequencies were similar for all work tasks indicating that shoulder muscle loads may be unaffected by large variations in arm movement frequencies and work cycle times. An exposure variation analyses (EVA) showed that the EMG activity patterns recorded during production work were more repetitive than during CAD work, whereas CAD work was associated with more static muscle activity patterns, both may be associated with a risk of developing musculoskeletal symptoms. Secondly, upper trapezius EMG activity patterns recorded on the mouse side of the CAD operators were compared with those recorded on the non-mouse side to study differences in muscular responses potentially related to the risk of developing shoulder symptoms which were more prevalent on the mouse side. The number of EMG gaps on the mouse side were significantly lower than the values for the upper trapezius on the non-mouse side indicating that more continuous activity was present in the upper trapezius muscle on the mouse side and EVA analyses showed a more repetitive muscle activity pattern on the mouse side. These findings may be of importance to explain differences in the prevalence of shoulder symptoms.

The safety and effectiveness of esmolol in the perioperative period in patients undergoing abdominal aortic surgery

OBJECTIVES

To determine (1) if perioperative use of esmolol in major vascular surgery patients provides strict heart rate (HR) control, (2) what doses of esmolol are required to do this, and (3) does this control influence myocardial ischemia or result in adverse consequences.

DESIGN

Prospective study of 40 patients randomized to two groups: The HR was controlled to either less than 80 beats/min (group 80) or less than 110 beats/min (group 110) using esmolol. Patients were monitored continuously for electrocardiographic changes perioperatively. HR control began after induction of anesthesia and continued for 48 hours thereafter.

SETTING

Operating room and intensive care unit.

PATIENTS

Patients undergoing abdominal vascular surgery involving aortic cross-clamping.

INTERVENTIONS

Esmolol was titrated until the target HR was met.

MEASUREMENTS AND RESULTS

Only one patient demonstrated an adverse effect. The median infusion rates were 100 and 12.5 microg/kg/min for groups 80 and 110. Target HR was met less in group 80 than in group 110, primarily in the postoperative period. Ischemia patterns were not significantly different between groups.

CONCLUSION

Using esmolol for HR control in the intraoperative period for abdominal vascular surgery patients is effective and safe. HR control was much less effective in the postoperative period, but esmolol is safe when used at recommended doses. Further study with a larger number of patients is necessary to determine whether strict HR control with esmolol affects the incidence of myocardial ischemia or infarction in this patient population.

Flavin-containing monooxygenase-mediated N-oxidation of the M(1)-muscarinic agonist xanomeline

The involvement of flavin-containing monooxygenases (FMOs) in the formation of xanomeline N-oxide was examined in various human and rat tissues. Expressed FMOs formed xanomeline N-oxide at a significantly greater rate than did expressed cytochromes P-450. Consistent with the involvement of FMO in the formation of xanomeline N-oxide in human liver, human kidney, rat liver, and rat kidney microsomes, this biotransformation was sensitive to heat treatment, increased at pH 8.3, and inhibited by methimazole. The latter two characteristics were effected to a lesser extent in human kidney, rat liver, and rat kidney microsomes than were observed in human liver microsomes, suggesting the involvement of a different FMO family member in this reaction in these tissues. As additional proof of the involvement of FMO in the formation of xanomeline N-oxide, the formation of this metabolite by a characterized human liver microsomal bank correlated with FMO activity. The FMO forming xanomeline N-oxide by human kidney microsomes exhibited a 20-fold lower K(M) (average K(M) = 5.5 microM) than that observed by the FMO present in human liver microsomes (average K(M) of 107 microM). The involvement of an FMO in the formation of xanomeline N-oxide in rat lung could not be unequivocally demonstrated. These data and those in the literature suggest that the increased prevalence of N-oxidized metabolites of xanomeline after s.c. dosing as compared with oral dosing may be due to differences in the affinity of various FMO family members for xanomeline or to differences in exposure to xanomeline that these enzymes receive under different dosing regimens.

Methodologic aspects of acetylcholine-evoked relaxation of rabbit aorta

The acetylcholine-evoked relaxation of rabbit isolated thoracic aorta precontracted by phenylephrine was studied. Phenylephrine caused a steady contraction that was maintained for 6 h. In the presence of calcium disodium ethylenediaminetetraacetate (EDTA) and ascorbic acid the contraction decreased with time. N(G)-Nitro-L-arginine abolished the inhibitory effect of EDTA and ascorbic acid. Acetylcholine evoked a rapid concentration-dependent relaxation that recovered spontaneously and slowly, but fully, with time. Relaxation evoked by equieffective concentrations of carbachol and acetylcholine had the same time course. Cumulative addition of acetylcholine (10(-7)-3 x 10(-5) M) caused a marked relaxation that was reverted slightly at high concentrations. The relaxation was the same with rings derived from the upper, middle, and lower part of the thoracic aorta. Two consecutive concentration-response curves for acetylcholine obtained at a 2-h interval demonstrated a slight development of tachyphylaxis. The relaxation was inversely related to precontractile tension evoked by phenylephrine when expressed as a percentage, but independent when expressed as g tension. Storage of aorta in cold salt solution for 24 h did not alter the relaxation. EDTA and ascorbic acid did not alter the relaxation. It is concluded that (1) EDTA and ascorbic acid can not be used with impunity to stabilize catecholamines used as preconstriction agents; (2) the reversal of the acetylcholine-evoked relaxation is not due to hydrolysis of acetylcholine; (3) the relaxation is uniform in all segments of thoracic aorta; (4) cold storage of aorta does not alter the relaxation; and (5) acetylcholine releases the same amount of relaxing factor, irrespective of the precontractile tension.

Overactivation of phospholipase C-gamma1 renders platelet-derived growth factor beta-receptor-expressing cells independent of the phosphatidylinositol 3-kinase pathway for chemotaxis

We have previously shown that porcine aortic endothelial cells expressing the Y934F platelet-derived growth factor (PDGF) beta-receptor mutant respond to PDGF-BB in a chemotaxis assay at about 100-fold lower concentration than do wild-type PDGF beta-receptor-expressing cells (Hansen, K., Johnell, M., Siegbahn, A. , Rorsman, C., Engström, U., Wernstedt, C., Heldin, C.-H., and Rönnstrand, L. (1996) EMBO J. 15, 5299-5313). Here we show that the increased chemotaxis correlates with increased activation of phospholipase C-gamma1 (PLC-gamma1), measured as inositol-1,4, 5-trisphosphate release. By two-dimensional phosphopeptide mapping, the increase in phosphorylation of PLC-gamma1 was shown not to be selective for any site, rather a general increase in phosphorylation of PLC-gamma1 was seen. Specific inhibitors of protein kinase C, bisindolylmaleimide (GF109203X), and phosphatidylinositol 3-kinase (PI3-kinase), LY294002, did not affect the activation of PLC-gamma1. To assess whether increased activation of PLC-gamma1 is the cause of the hyperchemotactic behavior of the Y934F mutant cell line, we constructed cell lines expressing either wild-type or a catalytically compromised version of PLC-gamma1 under a tetracycline-inducible promoter. Overexpression and concomitant increased activation of wild-type PLC-gamma1 in response to PDGF-BB led to a hyperchemotactic behavior of the cells, while the catalytically compromised PLC-gamma1 mutant had no effect on PDGF-BB-induced chemotaxis. Furthermore, in cells expressing normal levels of PLC-gamma1, chemotaxis was inhibited by LY294002. In contrast, the increase in chemotactic response seen upon overexpression of PLC-gamma1 was not inhibited by the PI3-kinase inhibitor LY294002. These observations suggest the existence of two different pathways which mediate PDGF-induced chemotaxis; depending on the cellular context, the PI3-kinase pathway or the PLC-gamma1 pathway may dominate.

Role of laminin isoforms in glomerular structure

Laminin along with collagen type IV, proteoglycans, and entactin are major components of basement membranes. Basement membrane components are synthesized at high levels during development. The formation of specialized basement membranes may play important roles in cell and tissue function by influencing cell proliferation, phenotype, migration and gene expression as well as tissue architecture. The growing diversity of laminin isoforms influences the formation of distinct basement membranes. Many of the laminin chains sequenced to date are expressed during glomerular development under strict temporal control. Also, some studies suggest that additional laminin chains exist and contribute to unique isoforms expressed within the renal glomerulus. This article will review the status of characterization of laminin isoforms expressed by glomerular cells, point out possible differences in isoforms expressed by different species, and discuss the implications of the complexity of glomerular laminins. In order to fully understand the nature of the glomerular laminins and their importance, information from studies of cells in culture, whole tissue, and those that use molecular and protein analysis must be integrated.

Risk factors for lack of recovery of ADL independence after hospital discharge

OBJECTIVE

To determine risk factors for lack of recovery of independent functioning after hospitalization for acute medical illness.

DESIGN

Secondary analysis of cohort study of patients receiving home nursing after discharge.

SETTING

Evaluations performed in the home after discharge and 1 month later.

PARTICIPANTS

A total of 73 adults aged 65 years and older who were independent in activities of daily living (ADLs) before hospitalization and dependent at discharge.

MEASUREMENTS

Self-report and objective measures of function, mobility, and cognition.

OUTCOME

Return to independence in ADLs 1 month after discharge.

RESULTS

Fifty-nine percent of patients did not return to previous ADL independence by 1 month postdischarge. The likelihood for not recovering was 87% (95% CI, 70-100%) if a patient had a Mini-Mental State Examination score (MMSE) < 24 at discharge (P = .015). Among patients with good cognition, 85% (95% CI, 66-100%) of those who used an assistive device indoors before hospitalization did not recover (P = .007). Among patients with good cognition and no previous assistive device use, 73% (95% CI, 47-99%) of those with a Timed "Up and Go" of > or = 40 seconds did not recover (P = .012). The likelihood of recovery was high (76%, 95% CI 56-96%) if a patient had no assistive device prehospital, a good MMSE, and a Timed "Up and Go" of < 20 seconds.

CONCLUSION

We hypothesize that a classification strategy using cognition, prehospital mobility, and discharge physical performance will predict patients who are less likely to recover functional independence after hospitalization. If this is validated in future study, it may help clinicians identify patients who are more likely to benefit from additional intervention.

Dissecting functions of the retinoblastoma tumor suppressor and the related pocket proteins by integrating genetic, cell biology, and electrophoretic techniques

The members of the 'pocket protein' family, comprising the retinoblastoma tumor suppressor (pRB) and its relatives, p107 and p130, negatively regulate cell proliferation and modulate fundamental biological processes including embryonic development, differentiation, homeostatic tissue renewal, and defense against cancer. The large, multidomain pocket proteins act by binding a plethora of cell fate-determining and growth-stimulatory proteins, the most prominent of which are the E2F/DP transcription factors. These protein-protein interactions are in turn regulated by carefully orchestrated phosphorylation events on multiple serine and threonine residues of pRB, p107, and p130, events which are carried out, at least in part, by the cyclin-dependent kinases that form the key elements of the cell cycle machinery. Here we discuss the recently obtained new insights into the diverse functions of the pRB family, and show examples of how integration of genetic, cell biology, and a range of electrophoretic approaches help to advance our understanding of the biological roles played by the pocket proteins in both normal and cancer cells.

Overjet reduction and molar correction in fixed appliance treatment of class II, division 1, malocclusions: sagittal and vertical components

The purpose of this study was to quantitatively evaluate skeletal and dental changes contributing to Class II correction in patients treated with the Begg technique. The sample consisted of 18 male subjects with Class II, division 1, malocclusions treated with fixed appliances (Begg technique, nonextraction) for an average period of 1.3 years (standard deviation, 0.24 years). Lateral radiographs in habitual occlusion taken at 6 months before the start of treatment, at the start of treatment, and 6, 12, and 18 months after the start of treatment were analyzed. During the control period, normal sagittal and vertical growth changes occurred. In the initial treatment period (0 to 6 months), the overjet reduction (6.6 mm; P <. 001) and the molar correction (2.2 mm; P <.001) were obtained mainly by dental movements. The overbite was reduced by 4.1 mm (P <.001). The NSL/ML and NL/ML angles increased by 1.5 degrees (P <.05) and 1. 4 degrees (P <.01), respectively, and the anterior lower facial height increased by 3.1 mm (P <.001). During the second period of treatment (6 to 12 months), the molar correction continued to improve, and the anterior lower facial height continued to increase. During the third period (12 to 18 months), a small relapse in overjet and overbite was noted, but the anterior lower facial height continued to increase. During the total treatment period (0 to 18 months), the overjet reduction and molar correction were 5.8 mm (P <. 001) and 3.0 mm (P <.001), respectively. Mandibular growth exceeded maxillary growth by 1.1 mm (P <.01). The overbite correction and the increase in anterior lower facial height were 3.0 mm (P <.001) and 5. 0 mm (P <.001), respectively. The NSL/ML angle increased 1.0 degrees (P <.05). The conclusions were that the changes contributing to the Class II correction were mostly dental. Vertically, the net effects of treatment were an increase in the mandibular plane angle and in lower anterior facial height.

A new measure for distress during child sexual abuse examinations: the genital examination distress scale

OBJECTIVE

The primary aim was to develop a simple scale to quantify indices of emotional distress during the rectal-genital (anogenital) phase of a child sexual abuse examination.

METHOD

A scale successfully developed to measure reactions of children to painful procedures, in particular bone marrow aspirations, was used as a model (Elliot, Jay, & Woody, 1987). This new scale was developed to have a simplified rating format, more relevant operational definitions and possibly a different set of behavioral categories. This new scale was developed using 300 children being examined for possible child sexual abuse. Intraclass correlation coefficients identified reliable items to use. Factor analysis and Cronbach alpha were employed to understand the internal structure of the scale. Paired t-tests, Pearson correlations and hierarchical regression were used to explore validity.

RESULTS

A simple 7-item scale was developed along with two subscales representing agitated and verbally mediated distress. Ratings of distress were significantly greater during the anogenital phase than the general physical part of the examination. Increased distress was associated with positive physical findings. Ratings by the children that they disliked the physician looking at their bodies provided discriminant validity by correlating with increased scores for emotional distress during the anogenital segment of the examination.

CONCLUSION

The Genital Examination Distress Scale (GEDS) has been developed for measuring the emotional distress of children during the anogenital component of child sexual abuse examinations. The GEDS has been provided for prudent use. Descriptive data offer a comparative standard for other programs and research.

Peptide-based OspC enzyme-linked immunosorbent assay for serodiagnosis of Lyme borreliosis

Sera from 210 patients with Lyme borreliosis (LB) were studied by an enzyme-linked immunosorbent assay (ELISA) based on a synthetic peptide (pepC10) comprising the C-terminal 10-amino-acid residues of OspC of Borrelia burgdorferi. We found that 36.3 and 45.0% of the serum samples from patients with erythema migrans (EM) and neuroborreliosis (NB), respectively, displayed immunoglobulin M (IgM) anti-pepC10 reactivities, while these samples rarely (</=8%) displayed IgG antibody reactivities. Sera from patients with acrodermatitis chronica atrophicans did not contain anti-pepC10 antibodies. The diagnostic performance of this newly developed peptide ELISA was compared with those of an ELISA based on the full-length recombinant OspC protein (rOspC) and a commercially available ELISA based on the B. burgdorferi flagellum (Fla). The sensitivity of the IgM pepC10 ELISA was slightly lower (P < 0.04) than that of the rOspC ELISA for EM patients (36.3 versus 43.8%), while there was no difference for NB patients (45.0 versus 48.0%). However, the optical density values obtained by the pepC10 ELISA were generally higher than those obtained by the rOspC ELISA, leading to a significantly better quantitative discrimination between seropositive patients with NB and controls (P < 0.008). The specificity of the pepC10 ELISA was similar to those of the rOspC ELISA and the Fla ELISA for relevant controls including patients with syphilis and mononucleosis. Although the overall diagnostic sensitivity of the Fla ELISA was superior, 8.8 and 12.0% of the EM and NB patients, respectively, were antibody positive only by the pepC10 ELISA. Thus, use of a diagnostic test for LB based on the detection of IgM antibodies to pepC10 and Fla has increased sensitivity for the diagnosis of early LB.

The cost of home-based care for HIV/AIDS patients in Zimbabwe

From a study on the cost and quality of community home-based care (CHBC) for HIV/AIDS patients in Zimbabwe, programme and household costs were estimated. Interviews, using a structured questionnaire, were held with 60 patients and caregivers sampled from six types of established CHBC schemes. Detailed cost information was collected from four home care programmes, two urban and two rural. The cost of a home visit in the two urban programmes studied was estimated to be Z$129 (US$16) in one, and Z$183 (US$23) in the other. In one of the two rural schemes, the cost of a home visit was Z$313 (US$38), in the other this was Z$343 (US$42). A large proportion of these costs were not of direct benefit to the patients, as approximately 56-75% of the total cost per home visit was spent getting to the patient. The costs of a home visit in a rural home-based care programme corresponded to the costs of 2.7 inpatient days in a district hospital. The family cost of caring for a bedridden AIDS patient over a three-month period was estimated to be between Z$556-841. Caregivers spent as much as 2.5-3.5 hours a day on routine patient care. The programme costs are high, and schemes do not generally assess effectiveness, nor cost-effectiveness. The high cost of home visits leads to less frequent visits, leaving a larger part of both the burden and the cost of care to the families and the patients.

New aspects of chemoreception in flies

For studies of insect taste the sensory cells of labellar taste hairs on the proboscis of calliphorid flies (e.g., Phormia) are preferred objects. Three sensory cells are electrophysiologically characterized: a sugar cell, a water cell and a cation or salt cell. Studying hairs on legs and proboscis of other families of flies we recently obtained results that extend our knowledge about the complexity of food detection in flies. The hoverfly Eristalis tenax (Syrphidae family) feeds on nectar and pollen of flowers. While nectar is recognized via the sugar cell, the so-called salt cell is activated by low concentrations of a water-soluble substance in extracts of pollen. From several tested pollen constituents only proline, an essential amino acid for pollen germination, stimulates the salt cell. The discrimination between salt and pollen in behavioral tests can be explained by the finding that the water cell remains active in the presence of pollen extract, but is inhibited by salts. Obviously the water cell activity is involved in the feeding decision. We already described a similar situation in Phormia, where the salt cell activity only elicits feeding behavior when the water cell is active too. In contrast to the sugar cells of species of flies studied so far the sugar cell of the house fly Musca domestica (Muscidae family) is highly sensitive to lactose, a disaccharide (beta-galactoside (1-->4) glucoside) naturally occurring only in the milk of mammals. Thus sugar spectra adapt to special environmental food situations. The fifth tarsomere of the forelegs of Musca bears besides two D-hairs 46 hairs of the B-type. The B-hairs are functionally not uniform in contrast to their structural identity. Only two hairs, the 'water hairs,' contain a water cell beside a spontaneously firing cell, but no sugar cell. Other examples of diversity are hairs that contain apart from the classical sugar cells, additional cells which react either to p-nitrophenyl-beta-galactoside, but not to the chemically related lactose, or to p-nitrophenyl-alpha-glucoside. Therefore the rule established for the labellar taste hairs that each hair type contains the same physiological equipment of sensory cells, does not hold for the taste hairs of the legs.

Job demands, muscle activity and musculoskeletal symptoms in relation to work with the computer mouse

OBJECTIVES

This study assessed work postures, movements, psychosocial job demands, and shoulder and wrist extensor muscle activity and registered the prevalence of musculoskeletal symptoms of computer-aided design (CAD) operators.

METHODS

A questionnaire survey was used to study the use of the computer mouse, psychosocial work factors, and musculoskeletal symptoms among 149 CAD operators. A workplace study was performed using observations, electrogoniometers on the wrists, and electromyography to measure exposures and physiological responses during CAD work among a subgroup of the CAD operators.

RESULTS

Musculoskeletal symptoms were far more prevalent for the arm or hand operating the mouse than for the other arm or hand, and women were more affected than men. The symptoms may be related to such risk factors as repetitive movements, static postures (eg, ulnar-deviated and extended wrist on the mouse side), and static muscular activation patterns. The risk factors were present due to continuous mouse use and possibly also due to high demands for mental attentiveness, precision, and information processing.

CONCLUSIONS

Exposure during work with a computer mouse may present a risk for developing musculoskeletal symptoms. Improvements should focus on introducing more variation.

Immunoserologic evidence of Human Granulocytic Ehrlichiosis in Danish patients with Lyme neuroborreliosis

Human Granulocytic Ehrlichiosis (HGE) is a recently described human illness in the US which manifests as fever, myalgia and headache combined with pancytopenia and elevated concentrations of hepatic transaminases. Genetic analyses indicate that the agent of HGE appears to be an Ehrlichia species that is closely related to E. equi and E. phagocytophila. Ixodes dammini and I. scapularis were identified as potential vectors of HGE. Ixodes ticks are also the vector of Borrelia burgdorferi, the agent of Lyme borreliosis. The presence of antibodies against Ehrlichia in 132 sera from Danish patients with definite Lyme neuroborreliosis were examined in order to provide immunoserologic evidence of this infection in Denmark. Patients with Lyme neuroborreliosis were chosen as a test cohort, as these patients had been infested by a tick sufficient for transmission of B. burgdorferi. All had cerebrospinal fluid lymphocytic pleocytosis. As controls, serum samples from 50 healthy Danish blood donors were included. Of the 132 patients with Lyme neuroborreliosis, 5 (3.8%) reacted with the E. equi antigen substrate at titres 1:128. None of the blood donors were found seropositive for E. equi. At least 2 of the patients found seropositive for HGE constituted probable cases of HGE with E. equi antibody titres of at least 80 combined with fever, headache and myalgias. However, in no cases were we able to detect the presence of the HGE agent in the serum by PCR. We conclude that human exposure to granulocytic Ehrlichiae species may also occur in Europe, although further studies will be necessary to document active infection with these potential pathogens.

The dominant epitope of Borrelia garinii outer surface protein C recognized by sera from patients with neuroborreliosis has a surface-exposed conserved structural motif

Epitope mapping of outer surface protein C (OspC) by using sera from patients with neuroborreliosis led to the identification of one single major immunodominant epitope within the C-terminal 10 amino acid residues. Peptide binding studies and alanine replacement scanning of the C-terminal decapeptide, PVVAESPKKP, revealed a critical role for the PKKP sequence and its terminal carboxyl group for the binding of immunoglobulin M (IgM) antibodies from patients with Lyme borreliosis. Electron microscopy of antibody-labeled spirochetes indicated that the C-terminal region is exposed on the surface of the spirochete. Based on homology to proteins of known function, this region most probably adopts a polyproline II-like helix, which is found in surface-exposed structures involved in protein-protein interactions. This structural motif is highly conserved in Borrelia species causing Lyme borreliosis and subjected to purifying selection. We suggest that the abundance of the C-terminal region of OspC on the surface of B. burgdorferi allows a multimeric high-avidity interaction between the spirochete and surface Igs on B cells. The resulting cross-linking of surface Igs on B cells may induce a T-cell-independent B-cell activation without IgM-to-IgG switching, thus explaining the lack of IgG antibodies to OspC in neuroborreliosis.

Does orthodontic proclination of lower incisors in children and adolescents cause gingival recession?

In this investigation we sought to assess the effect of orthodontic proclination of lower incisors in children and adolescents with respect to the possible development of gingival recession. Ninety-eight children with a mean +/- SD start-of-treatment age of 12.8 +/- 1.4 years, treated with the Herbst appliance, were surveyed, for a total of 392 lower incisors. Lateral head films, dental casts and intraoral photographs were analyzed with respect to the degree of orthodontic proclination, crown height, and gingival recession. In all subjects, Herbst treatment resulted in varying degrees of lower-incisor proclination (mean = 8.9 degrees, range = 0.5 degrees to 19.5 degrees). In 380 of the surveyed teeth (97%), either no recession developed or preexisting recession remained unchanged during Herbst therapy. In only 12 teeth (3%) did recession develop or preexisting recession deteriorate during treatment. No interrelation was found between the amount of incisor proclination and the development of gingival recession. In conclusion, orthodontic proclination of lower incisors in children and adolescents seems not to result in gingival recession.

Nascent transcription from the nmt1 and nmt2 genes of Schizosaccharomyces pombe overlaps neighbouring genes

We have determined the extent of the primary transcription unit for the two highly expressed genes nmt1 and nmt2 of Schizosaccharomyces pombe. Transcription run-on analysis in permeabilized yeast cells was employed to map polymerase density across the 3'-flanking region of these two genes. Surprisingly, polymerases were detected 4.3 kb beyond the nmt1 polyadenylation [poly(A)] site and 2.4 kb beyond the nmt2 poly(A) site, which in each case have transcribed through an entire convergent downstream transcription unit. However, the steady-state levels of both downstream genes were unaffected by the high level of nmt1 or nmt2 nascent transcription. Analysis of nmt1 and nmt2 RNA 3' end formation signals indicates that efficient termination of transcription requires not only a poly(A) signal but also additional pause elements. The absence of such pause elements close to the poly(A) sites of these genes may account for their extended nascent transcripts.

Acute effects of recombinant human interleukin-6 on endocrine and central nervous sleep functions in healthy men

Interleukin-6 (IL-6) is a proinflammatory cytokine that has been shown to mediate, in addition to immune reactions, various endocrine and central nervous components of the acute phase response. In this context, the present study aimed to specify the contributions of IL-6 to the regulation of pituitary-adrenal secretory activity and GH and TSH secretion, as well as to the regulation of central nervous sleep and mood in healthy men. Effects of a low dose of IL-6 (0.5 microgram/kg body weight) were assessed, inducing plasma IL-6 concentrations closely comparable with those typically observed after infectious challenge. Each of the 16 male subjects participated in two 14-h sessions (between 1800 and 0800 h), receiving either placebo or human recombinant IL-6 sc at 1900 h. Blood was collected repeatedly to determine plasma hormone levels, serum concentrations of cytokines, and C-reactive protein. Moreover, mood was assessed, and sleep recordings were obtained between 2300 and 0700 h. The cytokine induced a prolonged increased in plasma concentrations of ACTH and cortisol (P < 0.001), but led to a decrease in TSH concentrations (P < 0.01). In response to IL-6, subjects reported fatigue and felt more inactive and less capable of concentrating than after placebo. Sleep architecture was altered significantly by the cytokine. Slow-wave sleep was decreased during the first half and increased during the second half of sleep. Rapid eye movement sleep during the entire nocturnal sleep time was significantly decreased. After IL-6, body temperature rose slightly. C-reactive protein concentrations were dramatically increased 12.5 h after substance administration (P < 0.001). IL-6 did not affect serum concentrations of IL-2, IL-8, interferon-alpha, and interferon-gamma. The results underscore the importance of IL-6 in the cascade of cytokines for the neuroendocrine response during the acute phase reaction. In addition, IL-6 appears to be involved in changes of sleep and behavior accompanying infection and inflammatory disorders.

Analysis of low-dose digital lateral cephalometric radiographs

OBJECTIVE

To examine the effects of the dose reduction obtained with photostimulable phosphor computed radiography (CR) on the identification of cephalometric landmarks.

METHODS

Dose reductions of 50% and 75% respectively were obtained by placing three storage phosphor image plates in the same cassette. Lateral cephalograms were exposed on ten patients. Seven observers identified 14 anatomical landmarks on the images.

RESULTS

The location of anatomical landmarks on the lateral cephalograms was not effected by the decreased dose (P > 0.05). Interobserver variation was the major influence.

CONCLUSION

A dose reduction of 75% does not effect the localization of anatomical landmarks in lateral cephalograms obtained with CR.

Metastasis-associated Mts1 (S100A4) protein modulates protein kinase C phosphorylation of the heavy chain of nonmuscle myosin

Mts1 protein (S100A4 according to a new classification) has been implicated in the formation of the metastatic phenotype via regulation of cell motility and invasiveness. Previously we have demonstrated that Mts1 protein interacted with the heavy chain of nonmuscle myosin in a calcium-dependent manner. To elucidate the role of the Mts1-myosin interaction, we mapped the Mts1-binding region on the myosin heavy chain molecule. We prepared proteolytically digested platelet myosin and a series of overlapped myosin heavy chain protein fragments and used them in a blot overlay with Mts1 protein. Here we report that the Mts1-binding site is located within a 29-amino acid region, at the C-terminal end of the myosin heavy chain (between 1909-1937 amino acids). Two-dimensional phosphopeptide analysis showed that Mts1 protein inhibits protein kinase C phosphorylation of the platelet myosin heavy chain at Ser-1917. We hypothesize that Mts1 protein regulates cytoskeletal dynamics of the metastatic cells through modulation of the myosin phosphorylation by protein kinase C in calcium-dependent fashion.

Human carcinoma-associated antigen (HCA), isolated from the endometrial carcinoma cell line KLE-1 and ascitic fluid of a patient with ovarian carcinoma; comparison with epiglycanin

Human carcinoma-associated antigen (HCA), detected by the mouse monoclonal anti-epiglycanin antibody, AE-3, has been isolated from ascitic fluid taken from a patient with metastatic ovarian adenocarcinoma and from spent medium of the human endometrial carcinoma cell line KLE-1 and compared with epiglycanin. The ascitic fluid and the spent medium were concentrated by a Filtron Ultrasette 100 K Omega membrane and fractionated by gel filtration on Sepharose CL-2B. The active fractions which consisted mainly of glycoproteins having relative molecular weights in the range 1000-2000 kDa compared to dextrans, were further purified by affinity chromatography on a column of immobilized AE-3. The active fraction was subjected to SDS-PAGE and blotted onto a PVDF membrane. The amino acid composition of HCA isolated from the two sources, were related but not identical and both showed some differences from the amino acid composition of epiglycanin. They all have, however, compositions typical of mucin-type glycoproteins. The isoelectric point for HCA from both KLE-1 and ascitic fluid were determined to be at pH 1.8 and the buoyant densities were about 1.4 g/ml as determined by cesium trifluoroacetate gradient centrifugation.

Sepsis evaluations in hospitalized infants with bronchiolitis

OBJECTIVES

To define variation in the decision to perform a sepsis evaluation in hospitalized infants with bronchiolitis, to define predictors of the decision and to measure the clinical and cost outcomes.

METHODS

Retrospective chart review of all nonintensive care unit infants < or = 60 days with any discharge diagnosis of bronchiolitis (n = 282 from 1993 to 1995 in a 232-bed pediatric hospital. Process variables included temperature at sepsis work-up or Tmax if no sepsis workup. Outcome variables were charges, length of stay, sepsis workup and serious bacterial infection.

RESULTS

There was no difference in mean temperature between groups with or without sepsis evaluation (38.1 degrees C, P = 0.75). Of 282 infants 140 had a sepsis workup; 5 (1.8%) had serious bacterial infection. Infants with sepsis workup had an average total charge of $4507 and length of stay of 3.4 days compared with $2998 and 2.8 days for those without (P = 0.0001 and P = 0.002, respectively). A multivariate logistic regression model was constructed with sepsis workup as the dichotomous dependent variable. Significant (P < or = 0.05) predictor variables with a positive coefficient were: higher bronchiolitis score and normal chest roentgenogram. Significant variables with a negative coefficient were: admission diagnosis of bronchiolitis, chest roentgenogram typical for bronchiolitis and age > 28 days.

CONCLUSIONS

Temperature was not a predictor of sepsis evaluation. Infants with respiratory distress and normal chest roentgenogram were more likely to receive sepsis evaluations; those with recognized typical bronchiolitis and those > 28 days of age were less likely. Risk of serious bacterial infection is low; the costs of a sepsis evaluation outweigh the benefits in infants with obvious bronchiolitis.

Interference of sugars with the binding of biotin to streptavidin and avidin

Streptavidin and avidin have found widespread use as detection reagents in immunology, biochemistry and cell biology due to their high affinity binding to biotin, but the cellular functions of these proteins are not known. We have found that various sugars interfere with the binding of streptavidin and avidin to biotin. Mannose was most effective in inhibiting the binding to biotin followed by other saccharides. The inhibitory effect is most probably due to interactions of the sugars with residues in the binding pocket of streptavidin and avidin for biotin. These results show that great caution has to be exercised in the evaluation of experiments conducted with these detection reagents in the presence of sugars.

PDGF-induced phosphorylation of Tyr28 in the N-terminus of Fyn affects Fyn activation

Binding of platelet-derived growth factor (PDGF) to its receptors leads to the activation of members of the Src family of protein tyrosine kinases. We show here that Fyn, a member of the Src family, is phosphorylated on Tyr28 in the unique N-terminal part of the molecule after interaction with the intracellular domain of the PDGF beta-receptor. Activated Fyn furthermore undergoes autophosphorylation on Tyr30, Tyr39 and Tyr420. When Fyn mutants with Tyr28, Tyr30 or Tyr39 replaced with phenylalanine residues were transfected into NIH3T3 cells a decreased activation after PDGF stimulation was seen, suggesting a functional importance of the N-terminal tyrosine phosphorylation of Fyn.

[Abuse of benzodiazepines among heroin addicts in Copenhagen]

Abuse of benzodiazepines among heroin addicts in Copenhagen. The aim of this study was to investigate the extent of benzodiazepine abuse among heroin addicts, and to examine whether the heroin addicts with and without benzodiazepine abuse differed socially and psychiatrically. Social and medical information was drawn from the records for 98 heroin addicts who were registered for treatment at the institution Distriktscenter Vestre between 1.2-30.9.1994. Information about psychiatric admissions was taken from the Danish Psychiatric Register. The results showed that the heroin addicts with and without benzodiazepine abuse do not differ with regard to psychiatric data and basic demographic data. However, addicts with concomitant benzodiazepine ab-use were worse off concerning housing conditions, employment criminal records and amount and type of heroin abuse, and are thus in need of a more concerted treatment effort.

Cyberspace 101: taking a ride on the information superhighway

All you need to explore cyberspace is a computer, a modem, a phone line, and a local "on-ramp" to the infohighway. A litserv is an interactive mailing list that distributes information to a large number of people at the same time. Once you subscribe, you receive copies of all messages sent into listserv and have the opportunity to post questions and comments for other subscribers. Dietetics Online: A Network of Dietetic/Nutrition Professionals offers a range of cutting-edge services. Online marketing can reach a potentially larger audience for a fraction of the cost of traditional means and expand your business geographically.

[Low back pain problems among steelworkers]

The associations between low-back pain and occupational work loads, life-style factors, and sociodemographic factors were examined in 469 steel plant workers (436 males, 33 females), mean age (sd): 40 (12) years. Fifty-one per cent had experienced low-back pain during the preceding year. The strongest associations were found between recent low-back pain and domestic recreational activities (> or = h/wk vs 0-2 h/wk), and between recent low-back pain and work pace (too fast vs. adequate), odds ratios (95% confidence limits) being respectively 3.0 (1.5-5.8), and 2.3 (1.2-4.2). We considered a subject to have a particularly severe history of low-back pain if he or she due to low-back trouble (i) had ever been admitted to a hospital, (ii) had ever had to change work or, (iii) had had more than one week's sick-leave accumulated during the preceding year. There was a strong association between a severe low-back pain history and life-time occupational exposure to heavy and frequent lifting on the job. Forty-seven per cent of severe low-back pain events could be ascribed to heavy and frequent lifting, provided the associations were causal. We conclude that domestic recreational activities may be an important potential confounder in studies on occupational risk factors for low-back pain, and that, based on the results of this and of other studies, a case for prevention still seems to exist regarding lifting of heavy burdens in the work environment.

Cystic dysplasia of the rete testis: a benign congenital lesion associated with ipsilateral urological anomalies

PURPOSE

Cystic dysplasia of the rete testis is a benign congenital lesion that can mimic testicular cancer. We report 6 cases, review the literature, discuss the embryological etiology and make management recommendations.

MATERIALS AND METHODS

The records and pathology reports of 6 boys presenting with cystic dysplasia of the rete testis at 5 institutions were reviewed, as was the relevant literature.

RESULTS

Of the 6 cases 5 presented as scrotal masses in previously healthy boys and 1 as an abdominal mass in a newborn with multiple congenital anomalies. One patient had been followed from birth for a multicystic dysplastic kidney and 4 were found to have an ipsilateral absent kidney during evaluation. Development of the contralateral side was normal in most cases.

CONCLUSIONS

Cystic dysplasia of the rete testis is an unusual, benign congenital lesion that can mimic testicular cancer in presentation. The presence of ipsilateral renal anomalies, particularly renal agenesis, can suggest cystic dysplasia of the rete testis in the differential diagnosis preoperatively. Even if cystic dysplasia of the rete testis is suspected, we recommend inguinal exploration and early control of the spermatic cord in the event that neoplasia is identified. If possible, the goal of preserving as much normal testicular parenchyma as possible is desirable. Long-term followup for possible recurrence is recommended, particularly after local excision.

The role of p53 tumor suppressor gene and bcl-2 protooncogene in rat corpus luteum death

OBJECTIVE

The purpose of this study was to find out whether the mammalian corpus luteum undergoes genetically programmed cell death as evidenced by the positive or negative expression of specific biochemical markers of apoptosis (p53 and bcl-2).

STUDY DESIGN

Twenty-six immature 28-day-old female Sprague-Dawley rats were given 10 IU of pregnant mare's serum gonadotropin to induce ovulation and corpus luteum formation. Corpora lutea were collected on postovulatory days 8, 10, 12, and 14 and snap-frozen immediately. Determinations of apoptotic fragmentation of deoxyribonucleic acid were performed with use of samples radiolabeled at 3'-ends with deoxynucleotide alpha-phosphorus 32-deoxycytidine triphosphate (3000 Ci/mmol). Transcription of p53 and bcl-2 was determined by Northern blot analysis of total ribonucleic acid. Protein expression of p53 and bcl-2 was determined by Western blot analysis with a monoclonal rat antibody for p53 and a polyclonal rabbit antibody for bcl-2.

RESULTS

The nuclear fragmentation assay revealed formation of oligonucleosomes resulting in typical laddering of the deoxyribonucleic acid (corpus luteum) consistent with programmed cell death. Northern blot analysis of total ribonucleic acid prepared from immature (28-day-old) rat corpus luteum revealed the presence of a single p53 messenger ribonucleic acid transcript (2.1 kb) in all ages of corpus luteum studied from day 8 to day 14. Western blot analysis for p53 revealed a gradual reduction in p53 protein in corpus luteum from day 8 to day 12 until it became undetectable on day 14. Western blotting revealed expression of specific protein for bcl-2.

CONCLUSIONS

It appears that programmed cell death, as evidenced by formation of oligonucleosomes, occurs during mammalian luteal regression. The patterns of p53 ribonucleic acid expression in the corpus luteum suggest that the protein products of p53 and bcl-2 do not act in a diametric manner to regulate programmed cell death in the corpus luteum. The current results suggest that the mechanisms leading to programmed cell death in the mammalian corpus luteum may differ considerably from those in other organ systems.

Systemic immune changes following meal intake in humans

Food intake represents a high intestinal antigen exposition requiring host defense. Besides local immune activation, this defense includes a coordinate systemic immune response, which may serve to support local immunity. This study examined influences of a standardized high-protein meal on peripheral blood mononuclear cell counts; on the in vitro mitogen-stimulated production of tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, and interferon-gamma; on the in vivo plasma levels of tumor necrosis factor-alpha and interleukin-6; and on plasma concentrations of cortisol and growth hormone. Ten healthy men (18-35 yr) participated in two experimental sessions in a balanced order. On one occasion, subjects fasted; on the other, they received a high-protein meal at 1230. Blood was sampled every 15 min. Whereas the numbers of neutrophils and platelets were increased for more than 2.5 h after meal intake (P < 0.01) lymphocyte counts decreased (P < 0.01). Meal intake also decreased the production of interferon-gamma but did not affect the production and plasma levels of the other cytokines. Changes in immune cell distribution and function were accompanied by a strong postprandial rise in plasma cortisol concentrations. Some of the systemic immune changes, like the emigration of lymphocytes, probably into extravascular abdominal tissues, may serve to support local immune defense.

The mechanism of Class II correction in late Herbst treatment

The aim of this study was to analyze quantitatively the sagittal skeletal and dental changes contributing to Class II correction in patients treated with the Herbst appliance after the pubertal growth peak. The sample consisted of 21 subjects with a Class II, Division 1 malocclusion treated during the skeletal maturity stages MP3-H and -1, corresponding to a period after the maximum of pubertal growth (late treatment). A comparison was made with 22 Herbst subjects treated during the skeletal maturity stages MP3-E and -F, corresponding to a period before the maximum of pubertal growth (early treatment). Lateral head films from before and after Herbst therapy were analyzed, according to the method of Pancherz. As a result of the Herbst therapy, all patients attained a Class I or overcorrected Class I occlusal relationship. Class II molar correction averaging 6.1 mm was due to 37% skeletal and 63% dental changes. Overjet correction averaging 8.4 mm was due to 27% skeletal and 73% dental changes. Differences between the late and the early treated patients were only found for the dental changes. The upper anterior teeth were retroclined and the lower anterior teeth were proclined more in the late cases. The conclusion of the study was that the Herbst appliance is equally efficient in patients treated before and after the pubertal peak of growth. However, proclination of the lower incisors (anchorage loss) in late treated subjects is larger than in early treated subjects. This should be considered in treatment planning.

Long-term effects of Herbst treatment on the mandibular incisor segment: a cephalometric and biometric investigation

The purpose of this study was to analyze mandibular incisor changes during and after Herbst treatment with respect to tooth inclination and anterior crowding. The sample consisted of 24 Class II, Division 1 subjects (15 boys and 9 girls) treated with Herbst appliance. Dental casts and lateral head films from before and after treatment, 6 months after treatment and at the end of the growth period (at least 5 years after treatment) were analyzed. During treatment, the lower incisors were proclined (ILi/ML) an average of 10.8 degrees and the incisal edge (li) moved anteriorly by 3.2 mm. The available space and the irregularity index in the lower anterior region were in general unaffected by therapy. During the first posttreatment period of 6 months, the lower incisor inclination (ILi/ML) recovered an average of 7.9 degrees and the incisal edge (li) moved posteriorly by 2.5 mm. However, the available space was almost unchanged. During the second posttreatment period, i.e., from 6 months after treatment to the end of growth, the lower incisor inclination remained on average unchanged in relation to the mandibular plane (ILi/ML) but the teeth retroclined in relation to the nasion-sella line (ILi/NSL). The available space decreased (mean 0.8 mm, p < 0.01) and the irregularity index increased (mean 2.0 mm, p < 0.01). The correlation between changes in the ILi/NSL and in the NSL/ML angles was moderate (r = -0.57, p < 0.01), indicating that the reduction in the ILi/NSL angle was partly a result of anterior mandibular growth rotational changes. In conclusion, it can be said that the proclination of the lower front teeth during Herbst treatment did not result in incisor crowding after treatment. In a long-term perspective, the development of incisor crowding was thought to be associated with normal craniofacial growth changes.

Association of coatomer proteins with the beta-receptor for platelet-derived growth factor

The nonreceptor tyrosine kinase Src binds to and is activated by the beta-receptor for platelet-derived growth factor (PDGF). The interaction leads to Src phosphorylation of Tyr934 in the kinase domain of the receptor. In the course of the functional characterization of this phosphorylation, we noticed that components of 136 and 97 kDa bound to a peptide from this region of the receptor in a phosphorylation-independent manner. These components have now been purified and identified as alpha- and beta'-coatomer proteins (COPs), respectively. COPs are a family of proteins involved in the regulation of intracellular vesicle transport. In order to explore the functional significance of the interaction between alpha- and beta'-COP and the PDGF receptor, a receptor mutant was made in which the conserved histidine residue 928 was mutated to an alanine residue. The mutant receptor, which was unable to bind alpha- or beta'-COP, showed a normal ligand-induced autophosphorylation. The mutant receptor also behaved like the wildtype receptor with regard to biosynthesis and maturation, and mediated a mitogenic signal. The possible functional importance of the interaction between the PDGF beta-receptor and alpha- and beta'-COP, is discussed.

Transcriptional termination signals for RNA polymerase II in fission yeast

Transcription 'run-on' (TRO) analysis using permeabilized yeast cells indicates that transcription terminates between 180 and 380 bp downstream of the poly(A) site of the Schizosaccharomyces pombe ura4 gene. Two signals direct RNA polymerase II (pol II) to stop transcription: the previously identified 3' end formation signals located close to the poly(A) site and an additional downstream element (DSE) located at the region of termination. The downstream signal (135 bp) appears to act by pausing the elongating polymerase. TRO analysis indicates that elevated levels of transcribing polymerases accumulate over the DSE and that removal of this signal leads to transcription proceeding beyond the normal termination region. Furthermore, when inserted between two competing polyadenylation signals, this DSE increases the utilization of upstream poly(A) sites in vivo. We show that polymerase pausing over an extended region of template ensures termination of pol II transcription close to the poly(A) site.

Phosphorylation of a 72-kDa protein in PDGF-stimulated cells which forms complex with c-Crk, c-Fyn and Eps15

Ligand-induced activation of the beta-receptor for platelet-derived growth factor (PDGF) induces tyrosine phosphorylation of a number of downstream signaling proteins. In the present study, we used two-dimensional gel electrophoresis to characterize the spectrum of proteins phosphorylated in response to PDGF stimulation in porcine aortic endothelial cells expressing PDGF beta-receptors. Several previously known substrates for the PDGF beta-receptor were identified as well as a novel substrate of 72 kDa. The 72-kDa component could be co-immunoprecipitated in complex with the adaptor protein c-Crk, the non-receptor tyrosine kinase c-Fyn and the signaling molecule Eps15. The results obtained suggests that the 72-kDa protein might play an important role in signaling via the PDGF beta-receptor, coupling non-receptor tyrosine kinases of the Src family with c-Crk and Eps15.

Cyclin E-induced S phase without activation of the pRb/E2F pathway

In cells of higher eukaryotes, cyclin D-dependent kinases Cdk4 and Cdk6 and, possibly, cyclin E-dependent Cdk2 positively regulate the G1- to S-phase transition, by phosphorylating the retinoblastoma protein (pRb), thereby releasing E2F transcription factors that control S-phase genes. Here we performed microinjection and transfection experiments using rat R12 fibroblasts, their derivatives conditionally overexpressing cyclins D1 or E, and human U-2-OS cells, to explore the action of G1 cyclins and the relationship of E2F and cyclin E in S-phase induction. We demonstrate that ectopic expression of cyclin E, but not cyclin D1, can override G1 arrest imposed by either the p16INK4a Cdk inhibitor specific for Cdk4 and Cdk6 or a novel phosphorylation-deficient mutant pRb. Several complementary approaches to assess E2F activation, including quantitative reporter assays in live cells, showed that the cyclin E-induced S phase and completion of the cell division cycle can occur in the absence of E2F-mediated transactivation. Together with the ability of cyclin E to overcome a G1 block induced by expression of dominant-negative mutant DP-1, a heterodimeric partner of E2Fs, these results provide evidence for a cyclin E-controlled S phase-promoting event in somatic cells downstream of or parallel to phosphorylation of pRb and independent of E2F activation. They furthermore indicate that a lack of E2F-mediated transactivation can be compensated by hyperactivation of this cyclin E-controlled event.

Effects of sleep and circadian rhythm on human circulating immune cells

The role of nocturnal sleep for normal immune regulation and its relation to circadian rhythm was examined in 10 men participating in two 51-h sessions. One session included two regular wake-sleep cycles; the other included a night of sustained wakefulness followed by a night of recovery sleep. Blood was collected every 3 h to determine PBMC counts, including the enumeration of monocytes, NK cells, and lymphocyte subsets (CD19+, CD3+, CD4+, CD8+, HLA-DR+). Production of IL-1beta, TNF-alpha, IL-2, and IFN-gamma was determined after stimulation of whole blood samples with LPS and PHA, respectively. Concentrations of IL-6 and cortisol were assessed in plasma. Enumeration of cells indicated significant circadian rhythms for all PBMC subsets under conditions of sustained wakefulness. Compared with sustained wakefulness, nocturnal sleep acutely reduced the numbers of monocytes, NK cells, and counts of all lymphocyte subsets. However, in the afternoon and evening of the day following sleep, counts of NK cells and lymphocytes were significantly higher than after nocturnal wakefulness, indicating that effects of sleep interacted with those of the circadian pacemaker. Sleep markedly enhanced production of IL-2 by T cells (CD3+) but did not influence production of IL-1beta and TNF-alpha, or IL-6 concentrations. Effects of sleep were not mediated by changes in cortisol. The decrease in monocytes, NK cells, and lymphocytes, together with an increased production of IL-2 during sleep, may serve to support ongoing immune defense in extravascular lymphoid tissue during a time of diminished acute Ag challenge.

Nonpsychotic thought disorder: objective clinical identification of somatization and antisocial personality in language patterns

This report describes a new method of using language patterns to identify somatization and antisocial personality (ASPD) disorders in clinical practice. A set of definitions describing characteristic speech patterns was developed to identify "nonpsychotic thought disorder" (NPTD). Speech patterns of subjects with somatization disorder and/or ASPD were compared with those of controls. Blind raters assessed audiotaped samples of speech obtained through open-ended interviews for instances of elements of NPTD. Women with somatization or ASPD had significantly more NPTD speech responses than controls, and women with both disorders showed the greatest amount. Antisocial men did not demonstrate more NPTD than controls, nor was somatization in men associated with NPTD. Clinical attention to speech patterns in patients may help alert clinicians to these disorders in women and serve as indicators for screening for these disorders. More study is needed to develop psychometric properties of the instruments on larger samples, and to identify speech indicators of personality disorder in men. It is likely that other personality disorders, e.g., borderline personality disorder, can be identified through speech patterns, and they deserve study with these methods.

Effects of sleep and circadian rhythm on human circulating immune cells

The role of nocturnal sleep for normal immune regulation and its relation to circadian rhythm was examined in 10 men participating in two 51-h sessions. One session included two regular wake-sleep cycles; the other included a night of sustained wakefulness followed by a night of recovery sleep. Blood was collected every 3 h to determine PBMC counts, including the enumeration of monocytes, NK cells, and lymphocyte subsets (CD19+, CD3+, CD4+, CD8+, HLA-DR+). Production of IL-1beta, TNF-alpha, IL-2, and IFN-gamma was determined after stimulation of whole blood samples with LPS and PHA, respectively. Concentrations of IL-6 and cortisol were assessed in plasma. Enumeration of cells indicated significant circadian rhythms for all PBMC subsets under conditions of sustained wakefulness. Compared with sustained wakefulness, nocturnal sleep acutely reduced the numbers of monocytes, NK cells, and counts of all lymphocyte subsets. However, in the afternoon and evening of the day following sleep, counts of NK cells and lymphocytes were significantly higher than after nocturnal wakefulness, indicating that effects of sleep interacted with those of the circadian pacemaker. Sleep markedly enhanced production of IL-2 by T cells (CD3+) but did not influence production of IL-1beta and TNF-alpha, or IL-6 concentrations. Effects of sleep were not mediated by changes in cortisol. The decrease in monocytes, NK cells, and lymphocytes, together with an increased production of IL-2 during sleep, may serve to support ongoing immune defense in extravascular lymphoid tissue during a time of diminished acute Ag challenge.