p21-Activated Kinases in Thyroid Cancer

The family of p21-activated kinases (PAKs) are oncogenic proteins that regulate critical cellular functions. PAKs play central signaling roles in the integrin/CDC42/Rho, ERK/MAPK, PI3K/AKT, NF-κB, and Wnt/β-catenin pathways, functioning both as kinases and scaffolds to regulate cell motility, mitosis and proliferation, cytoskeletal rearrangement, and other cellular activities. PAKs have been implicated in both the development and progression of a wide range of cancers, including breast cancer, pancreatic melanoma, thyroid cancer, and others. Here we will discuss the current knowledge on the structure and biological functions of both group I and group II PAKs, as well as the roles that PAKs play in oncogenesis and progression, with a focus on thyroid cancer and emerging data regarding BRAF/PAK signaling.

MON-LB80 Human Thyroid Cancer Cells Are Highly Sensitive to CDK7 and 9 Inhibition

Cancer cells display lineage and cancer-specific transcriptional control of expression of oncogenic driver genes, particularly those regulated through super-enhancers. Compounds that target CDK7 and 9, key regulators of RNA polymerase II (RNAPII)-mediated gene transcription, selectively reduce transcription of “superenhanced” oncogenes and are in clinical trials. We previously identified that medullary cancer cell lines are highly sensitive to CDK7 inhibition and that the RET-gene is super-enhanced. In the present study, we sought to determine sensitivities of a panel of follicular cell-derived thyroid cancer cell lines to the CDK7 inhibitor, THZ1 and CDK9 inhibitor, AZD4573. We selected 8 independently confirmed thyroid cancer cell lines (TPC1, FTC133, BCPAP, SW1376; K1, THJ16, C643, and 8505C) from a variety of histological subtypes with different drive mutations and performed WST assays with increasing concentration of THZ1 or AZD4573 to determine IC₅₀ for each cell line. Western blots were performed in parallel for target validation. IC₅₀ values ranged from 5-100 nM for both compounds for all cell lines. All cell lines showed inhibition of CDK 7 phosphorylation (Ser 5) of RNAPII with retained CDK7 levels with THZ1 and loss of CDK9 RNAPII phosphorylation (Ser 2) with both compounds. However, treatment with either agent unexpectedly caused a reduction of total RNAPII protein levels. qRT-PCR did not reveal reduced mRNA levels in TPC1 cells with THZ1 treatment while, Bortezomib (proteasome inhibitor) co-treatment with THZ1 rescued RNAPII protein. These results are consistent with THZ1-induced proteasome degradation of RNAPII. BRAF protein levels also decreased in the hemizygous BRAF V600E-mutated cell line (8505C) but not the BRAF WT cell line (TPC1). qRT-PCR of both cell lines treated THZ-1 showed stable BRAF gene expression; further mechanistic studies are ongoing. In summary, human thyroid cancer cell lines are sensitive to inhibition of CDK7 and CDK9 likely through several mechanisms not all directly attributable to RNAPII inhibition.

A simple capillary viscometer based on the ideal gas law

We report a simple, inexpensive and user-friendly capillary viscometer based on the measurement of pressure drop in capillary tubing using the principle of ideal gas law. Viscosity is an important physical property of a fluid that provides molecular information of the fluid's behavior under flow conditions. Measuring viscosity, however, generally requires relatively large fluid volume samples and is expensive with commercial viscometers. Microfluidic viscometers at different levels of complexity can measure fluids at different flow rates with a small sample volume but the cost of commercially available microfluidic viscometers is still high. The reported capillary viscometer is cost-effective, uses small amounts of sample fluid and can measure viscosity under various shear rates. According to the Hagen–Poiseuille equation, the pressure drop of laminar flows in a capillary at a given flow rate is proportional to the viscosity of the fluid. When an enclosed air volume is connected to the upstream of the capillary, the pressure drop can be calculated with the change of the connected air volume, which is reflected by the displacement change of the air–liquid interface in the connecting capillary to the enclosed air volume. Based on these principles, the viscometer was assembled with readily accessible materials, and required no internal sensors or extensive programming. Measurements were successfully performed for five liquids including water, acetone, 2% fat milk, glycerin 30% and glycerin 40%. Except for acetone, the difference between measured and known viscosity was within 4% and highly consistent, well within the 13% uncertainty errors of readily accessible laboratory materials. Overall, the simple viscometer was easily assembled with low cost materials, was portable and accurate, and provided an alternative to expensive commercial viscometers. Finally, the simple capillary viscometer was a good outreach project for K-12 students to understand fluid behavior.

Fluid viscosity proportional to pressure drop in a capillary (L) was reflected by the air–fluid interface displacement (ΔL) to enclosed air.

Colombian study to assess the use of noninvasive determination of endothelium-mediated vasodilatation (CANDEV). Normal values and factors associated

The endothelium plays a critical role in vascular homeostasis. Recently, a noninvasive method has been developed to assess flow mediated vasodilatation of the brachial artery (FMD). This test is remarkably stable overtime but no clear set of normal values has been developed. The purposes of our study were to evaluate the accuracy and reproducibility and to identify a set of normal values of FMD. We included 253 normotensive healthy volunteers from three Colombian cities (mean age: 38.2 years; 33% were women). All subjects underwent ultrasound evaluation of endothelial and smooth muscle function. Flow mediated vessel diameter change was measured by two independent observers. The interobserver Lin's concordance correlation coefficient was 0.88% (95% CI: 0.82, 0.94) and there was no evidence of systematic difference between the two measurements (mean difference of -0.30% with limits of agreement of -4.48 to 3.87). Mean %FMD was 11.98% (95% CI: 11.36, 12.61), 13.32% (95% CI: 12.39, 14.25) in women and 11.32% (95% CI: 10.52, 12.13) in men. Subjects with no cardiovascular risk factors had a mean %FMD of 13.74% (95% CI: 13.14, 14.35), in contrast to a mean of only 7.40% (95% CI: 4.33, 9.91) in those with at least one risk factor. A %FMD cut point of 10.4 had a sensitivity of 71.2% and an specificity of 77.2% to identify subjects with at least one cardiovascular risk factor. Using this cut point, endothelial dysfunction was 3.13 times more frequent in subjects with than in subjects without cardiovascular risk factors (95% CI: 2.30, 4.25). In addition, obesity, smoking and hypercholesterolemia were the modifiable risk factors with largest independent significant reduction effects on %FMD. FMD measurements can be made with high accuracy and precision, and a cut point of 10.4% is useful to discriminate between subjects with and without cardiovascular risk factors, and can be recommended as a screening test for the detection of patients at risk of CVD.

An integrated proposal to explain the epidemic of cardiovascular disease in a developing country. From socioeconomic factors to free radicals

An increase of coronary artery disease has been observed in developing countries during the last years. Various factors may explain this accelerated increase. We propose that inappropriate diet and inadequate sanitary infrastructure may act as triggers to create an imbalance between nitric oxide (NO) and superoxide (O2-). An increase in the concentrations of oxidized LDL produces both decreased NO and increased O2- endothelial synthesis, by accumulation of asymmetrical NG-NG-dimethyl-L-arginine, the endogenous inhibitor of NO, and by activation of NAD(P)H oxidase. On the other hand, high rates of chronic infection-inflammation, due to inappropriate sanitary environment stimulate higher circulating levels of proinflammatory cytokines. These cytokines also contribute to reduced NO and increased O2- endothelial production through the same mechanisms of oxidized LDL. The net result of this imbalance is an increased generation of peroxynitrate that injures the endothelium in a proatherogenic, prothrombotic and vasoconstrictive manner.

[The Mini-Mental State Examination as a selected diagnostic test for dementia: a Colombian population study. GENECO]

INTRODUCTION

Folstein's Mini Mental State Examination (MMSE) is widely used as screening test for cognitive impairment.

OBJECTIVE

To test a Spanish version of the MMSE in a population of high illiteracy rate.

MATERIAL AND METHODS

Population-based survey of a stratified random sample of urban and rural residents of five regions of Colombia, followed by neurological and neuropsychological evaluation of suspect cases (phase 2). Dementia was diagnosed using DSM-IV criteria.

RESULTS

1,611 subjects age 50 or older filled out both the WHO Protocol for Epidemiologic Studies of Neurological Disorders and a Spanish version of the MMSE; 55.2% of them had three or less years of schooling; 536 individuals with scores below cutoff points were sent to phase 2. Of the population with satisfactory scores in MMSE 366 (34.0%) were evaluated by neurologists to exclude other neurological conditions. Twelve cases of dementia were diagnosed among individuals with scores below cutoff point and one among subjects with high scores. Age-adjusted prevalence was 8.1 per thousand subjects age 50 or over (95% CI: 3.7-12.5); and 34.2 per thousand for ages 75 or over (95% CI: 12.2-56.2). Sensitivity and specificity were 92.3 and 53.7%; 16 of the 19 questions show significant differences (p < 0.001) according to educational level. A gender gap is significant in low educational levels (p < 0.001) but not in subjects with more than five years of schooling.

CONCLUSIONS

MMSE scores correlated closely with level of education. Low specificity leads to many non-demented subjects with low educational status requiring further investigation.

Accuracy of four commercially available serologic tests, including two office-based tests and a commercially available 13C urea breath test, for diagnosis of Helicobacter pylori

BACKGROUND

Diagnosis of H. pylori infection may be made by endoscopic (invasive) tests, or by nonendoscopic (noninvasive) tests. Our aim was to evaluate recently available nonendoscopic tests, including two office-based serologic tests and a commercially available 13C urea breath test.

METHODS

Gastric biopsy specimens (for culture and stain) from 178 patients (mean age 46 +/- 13.3 years, 79 men and 99 women), none of whom had received anti-H. pylori therapy, were tested for H. pylori infection. These tests were compared against two commercial serum IgG antibody immunoassays (Biowhittaker's Pyloristat, and Quidel), 2 office-based serum qualitative IgG antibody tests (FlexSure HP, and QuickVue One-Step), the Meretek 13C urea breath test, and the CLOtest (a biopsy urease test).

RESULTS

The breath test (n = 147) had the best accuracy (96%) of the noninvasive tests studied. The serologic tests had similar accuracy to one another (84%-90%). The major drawback of the serologic tests was suboptimal specificity (75%-87%). Diagnosis of H. pylori based on the two office-based tests were not significantly different compared to the quantitative IgG antibody tests. The CLOtest had an accuracy of 97%.

CONCLUSIONS

The Meretek 13C urea breath test is an excellent test, but is considerably more expensive than serologic tests. The FlexSure HP and the QuickVue One-Step office-based qualitative IgG serologic antibody tests gave similar results to laboratory based quantitative antibody tests, and are acceptable for initial diagnosis of H. pylori infection. The advantages of the office-based tests are low cost, simplicity, and immediacy of results.

[Profile of drug addicts admitted to a hospital detoxification unit during a four-and-a-half year period]

It realize a overall and evolutionarily (6 months periods) study concerning the 1,313 drug dependents that were admitted to the Detoxication Unit of the Hospital Psiquiátrico de Madrid, since October 1985 to March 1990. The sociodemographic, drug dependence history, the Physical and toxicological state at admittance, the inpatient evolution, and the familiar and personal psychopathological history variables were evaluated. It bring out that the 45% are dependents to another drug apart from the heroin, the gradual increase in the mean age and in the use of the cocaine, a decrease in the use of the cannabis, anyway the appearance of the buprenorphine addition. There is a gradual decrease, in the period studied, of the antibodies HIV carrier rates. It shows that there is a relationship between this. The poly drug dependents have more legal incidences, psychopathological personal histories (heroin and alcohol and/or benzodiazepines addiction), use more the i.v. route and the HIV seroprevalence are the greatest.

[Stress factors in psychiatric hospitalization]

The incidence of stressful life events in the six months previous to psychiatric hospitalization is studied in a group of patients allotted to different diagnostic categories but which held in common that they were at their first episode of inpatient treatment. The presence of early life events during childhood and of chronic stress during the last year is also investigated. The different kind of responses to LE are described, classified in several categories. The incidence of LE in the patients is compared with that of a group of acute traumatologic hospital inpatients. In every case it has been used the Paykel LE rating scale, the Brown and Harris interview schedule and the GAF. Results are analyzed and their implications in preventive and treatment programs in Mental Health are discussed.

[Prevalence of infection by the human immunodeficiency virus type 1 in drug addicts in Madrid, over a 5 year period]

BACKGROUND

Firstly, to evaluate the annual levels of seroprevalence of antibodies against the type I human immunodeficiency virus in a sample of 1,232 intravenous drug users (IVDU) admitted for treatment to a hospital detoxication unit i Madrid over a period of 5 years. Secondly, attempt to distinguish the existence of variable which differentiate seropositive and seronegative IVDU.

METHODS

Data concerning sociodemographic profile and history of addiction were collected. The detection of antibodies vs HIV was carried out by the enzyme immunoanalysis technique which was confirmed by indirect immunofluorescence methods and western blot if positive.

RESULTS

There was a diminution in the levels of seropositivity during the 5 years evaluated (74%, 65%, 66%, 62% and 59%, p less than 0.05) with the infection by the HIV being more frequent in those addicted for a longer period of time, with more attempts at treatment, who had initiated drug dependence at an earlier age, had been in prison, and who, apart from heroin, also consumed benzodiacepins++ and/or alcohol.

CONCLUSIONS

A decrease in the levels of annual seroprevalence of HIV anti antibodies was found and the group of seropositive IVDU presents particular characteristics emphasizing the need for promoting treatment programs with adequate retention capacity for drug users.

[Factors affecting the course of hospital detoxication of drug addicts]

BACKGROUND

Despite the long waiting list (2-3 months) for entering the Detoxication Unit of the Psychiatric Hospital in Madrid, some of the drug addicts (DA) voluntarily give up treatment. This study attempts to outline the differences between the DA who successfully complete the treatment and those who fail.

METHODS

Anamnestic personal and family data and information concerning drug dependence collected from the clinical history of 1,313 DA admitted between October 1985 and March 1990 were analyzed. The sample was divided into 2 stages; the first being up to October 1988 in which adrenergic drugs (clonidine and guanfacine) were used and the second in which an opiacium agonist (methadone) was also taken. Two groups have been made according to the success and failure of the treatment.

RESULTS

In the first stage, the number of failures was greatest among those subjects with prison records (42% vs 27%, p less than 0.0001), heroin and cocaine addicts (33% vs 15%, p less than 0.001) and those whose urine analysis proved positive for cocaine on the day of hospital admission (46% vs 21%, p less than 0.0001). No differences were found in the second stage.

CONCLUSIONS

The possible usefulness of opiacium agonists vs adrenergic agonists in the detoxication of heroin and cocaine drug addicts are discussed in accordance with the knowledge obtained by other authors in preclinical studies.

Survival of some non-starter bacteria in naturally ripened and enzyme-accelerated Cheddar cheese

Effects of the addition of a proteinase (Neutrase 1-5S) and a peptidase (aminopeptidase DP-102) as agents for accelerating the ripening of Cheddar cheese on the survival of some non-starter bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and a Salmonella sp.) were studied throughout a 4-month ripening period. The enzymes were found to have no significant effect on the survival of the Gram-positive bacteria but some significant effects were observed, at some stages of the ripening period, with the Gram-negative bacteria in that lower levels were recovered from cheeses treated with the enzyme system.

Staphylococcus aureus, thermostable nuclease and staphylococcal enterotoxins in raw ewes' milk Manchego cheese

Growth and survival of two enterotoxigenic strains of Staphylococcus aureus were studied during manufacture and ripening of eight batches of raw ewes' milk Manchego cheese. Only 2-3 generations of Staph. aureus occurred in the vat and during pressing. The death rate of Staph. aureus (mean decrease in log cfu/g/week of ripening) from day 1 to day 60 was 0.421 in cheese made with 1% Streptococcus lactis starter and 0.404 in cheese made without starter. Thermostable nuclease was produced in the vat by growing Staph. aureus cells; it was inactivated by rennet during the first 24 h and synthesized again by surviving cells of Staph. aureus from day 1 to day 60. Staphylococcal enterotoxins A, B, C and D were not detected in any batches of cheese, even though Staph. aureus counts exceeded 10(7) cfu/g.

Influence of lactic starter inoculation, curd heating and ripening temperature on Staphylococcus aureus behaviour in Manchego cheese

Growth and survival of Staphylococcus aureus were investigated in 52 lots of raw ewe's milk Manchego cheese manufactured and ripened under different conditions. A 5.8-fold reduction in S. aureus counts after 60 days of ripening was obtained by inoculating milk with 1% Streptococcus lactis culture, and a further 2.0-fold reduction could be achieved by adding 0.1% Lactobacillus plantarum culture. Curd heating temperature had a significant effect on S. aureus survival, with counts 4-5 times lower in cheese from 30 degrees C curd than in cheese from curd heated at 36-40 degrees C. Ripening temperature was the parameter with the greatest influence on S. aureus counts, which reached in cheese cured at 10 degrees C or 20 degrees C for 60 days levels 10 and 100 times lower, respectively, than in cheese held at 5 degrees C.

A quantitative study of enterotoxin production by sheep milk staphylococci

Of 124 staphylococcal strains isolated from sheep milk, 78 produced enterotoxin A, B, C, or D when evaluated by an enzyme-linked immunosorbent assay. Enterotoxins A and D, elaborated by 44 and 43 strains, respectively, showed the highest incidence. Enterotoxin production by coagulase-negative strains (one Staphylococcus cohnii, three S. epidermidis, five S. haemolyticus, and four S. xylosus) was detected. Linear and logarithmic-logarithmic regressions of optical density on enterotoxin concentration yielded the best-fitting equations for enterotoxin quantitation. A significantly higher incidence of enterotoxin producers and significantly higher levels of enterotoxins produced were recorded for coagulase-positive, thermostable nuclease-positive, hemolysis-positive, or mannitol-positive strains. Mannitol utilization was the best test for discriminating between enterotoxigenic and nonenterotoxigenic staphylococci.

Seasonal variation and characterization of Micrococcaceae present in ewes' raw milk

Samples (120) of ewes' raw milk collected over a 12-month period on arrival at the dairy and freshly drawn ewes' milk samples (30) collected at the farm were analysed for total viable counts and staphylococci. Total viable counts reached on the average 5.4 X 10(6)/ml in dairy samples and 6.0 X 10(5)/ml in farm samples, whereas mean levels of staphylococci were 5.9 X 10(4)/ml and 3.3 X 10(3)/ml, respectively. A high proportion (62%) of coagulase-positive isolates from Baird-Parker agar plates was detected in spring months. Staphylococcus aureus (42%), Staph. haemolyticus (23%) and Staph. epidermidis (10%) were the predominant species in 210 characterized isolates of staphylococci from ewes' raw milk. Seven coagulase-positive, maltose-negative staphylococci could not be identified with any of the recognized Staphylococcus species. Eighteen Micrococcus strains were identified as M. varians, whereas 111 Micrococcus strains of uncertain taxonomic status were separated into three groups, according to their physiological characters.

Factors Affecting the Microbiological Quality of Burgos and Villalón Cheeses at the Retail Level

One hundred forty-four samples of Burgos and Villalón cheeses collected during April and July 1983 from retail outlets in Madrid, Spain, were analyzed for microbiological quality. Geometric mean counts were 6.8 × 10⁵ staphylococci/g, 1.0 × 10⁵ coliforms/g and 7.9 × 10³ yeasts/g for Burgos cheese, whereas the respective mean counts for Villalón cheese were 1.4 × 10⁶/g, 8.7 × 10⁴/g and 1.9 × 10⁴/g Coagulase-positive staphylococci represented in April and July, 7.9 and 42.2%, respectively, of the isolates from egg-yolk tellurite glycine agar plates. Fecal coliforms accounted for 5.6 and 26.9% of the isolates from violet red bile agar plates in April and July, respectively. Presence of alkaline phosphatase activity in cheese was not significantly related to numbers of staphylococci or coliforms and should only be regarded as a presumptive test. The use of pH values or total counts as indicators of the microbiological quality of Burgos and Villalón cheeses is also discussed.