The embryonic transcription factor Brachyury blocks cell cycle progression and mediates tumor resistance to conventional antitumor therapies.

The T-box transcription factor Brachyury, a molecule frequently detected in human cancers but seldom found in normal adult tissue, has recently been characterized as a driver of the epithelial-to-mesenchymal switch of human carcinomas. In the current investigation, we present data demonstrating that in two different human lung carcinoma models expression of Brachyury strongly correlates with increased in vitro resistance to cytotoxic therapies, such as chemotherapy and radiation. We also demonstrate that chemotherapy treatment in vitro selects for tumor cells with high levels of Brachyury and that the degree of resistance to therapy correlates with the level of Brachyury expression. In vitro and in vivo, human lung carcinoma cells with higher levels of Brachyury divide at slower rates than those with lower levels of Brachyury, a phenomenon associated with marked downregulation of cyclin D1, phosphorylated Rb and CDKN1A (p21). Chromatin immunoprecipitation and luciferase reporter assays revealed that Brachyury binds to a half T-box consensus site located within the promoter region of the p21 gene, indicating a potential mechanism for the observed therapeutic resistance associated with Brachyury expression. Finally, we demonstrate that in vivo treatment of tumor xenografts with chemotherapy results in the selective growth of resistant tumors characterized by high levels of Brachyury expression. Altogether, these results suggest that Brachyury expression may attenuate cell cycle progression, enabling tumor cells to become less susceptible to chemotherapy and radiation in human carcinomas.

Epidemic intelligence service of the Centers for Disease Control and Prevention: 50 years of training and service in applied epidemiology.

The Epidemic Intelligence Service (EIS) was established in 1951 at the Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, as a combined training and service program in the practice of applied epidemiology. Since then, nearly 2,500 professionals have served in this 2-year program of the US Public Health Service. The experience of an EIS Officer has been modified because of the increased need for more sophisticated analytical methods and the use of microcomputers, as well as CDC's expanded mission into chronic diseases, environmental health, occupational health, and injury control. Officers who have entered the EIS in the past 20 years are more likely than their predecessors to stay in public health either at the federal level or in state and local health departments. The EIS Program continues to be a critical source for health professionals trained to respond to the demand for epidemiologic services both domestically and internationally.

Thermal effects in laser-assisted pre-embryo zona drilling.

Diode lasers [lambda=1480 nm] are used with in vitro fertilization to dissect the zona pellucida (shell) of pre-embryos. A focused laser beam is applied in vitro to form a channel or trench in the zona pellucida. The procedure is used to facilitate biopsy or as a promoter of embryo hatching. We present examples and measurements of zona pellucida ablation using animal models. In using the laser it is vital not to damage pre-embryo cells, e.g., by overheating. In order to define safe regimes we have derived some thermal side effects of zona pellucida removal. The temperature profile in the beam and vicinity is predicted as function of laser pulse duration and power. In a crossed-beam experiment a HeNe laser probe is used to detect the temperature-induced change in the refractive index of an aqueous solution, and estimate local thermal gradient. We find that the diode laser beam produces superheated water approaching 200 degrees C on the beam axis. Thermal histories during and following the laser pulse are given for regions in the neighborhood of the beam. We conclude that an optimum regime exists with pulse duration < or =5 ms and laser power approximately 100 mW.

Influence of diabetes mellitus on patient and graft survival in recipients of kidney transplantation.

AIMS: To investigate the outcomes in patients who have pre-existing diabetes and those who develop post-transplant diabetes mellitus (PTDM). METHODS: We retrospectively reviewed the charts of 939 patients who received a first functioning renal transplant in the cyclosporine (CyA) era between 1984 and 1999. RESULTS: Sixty-six (7%) patients had renal failure due to insulin-dependent diabetes mellitus (IDDM) and 7 (0.8%) patients due to non-insulin-dependent diabetes mellitus (NIDDM). Ten (1.1%) patients had coexistent diabetes and 48 (5.1%) recipients developed PTDM. The mean graft survival for the patients with PTDM was 9.7 yr versus 11.3 yr for the non-diabetic patients, while mean graft survival was 10.1 yr for patients with IDDM and 2.9 yr with NIDDM and 8.3 yr for those with coexistent diabetes (p=ns). However, there was a statistically significant difference in patient survival between patients who developed PTDM and in those who did not develop this complication. The mean survivals of patients with IDDM, NIDDM, coexistent diabetics and PTDM were 8.4, 3.7, 8.6 and 10.3 yr, respectively. The mean survival of the patients without pre-existing diabetes or PTDM was 12.8 yr (p<0.001). The survival of patients older than 55 yr with PTDM was no different to the control group. However, in those younger than 55 yr, PTDM was associated with a higher risk of death (relative risk of 2.54, p<0.001). Fifty percent of patients with IDDM developed acute rejection episodes, whereas rejection rate was 57.1% in NIDDM group, 50.0% in the PTDM group, 20.0% in the coexistent diabetes group and 44.3% in the control group (p=ns). CONCLUSION: Patient survival, but not graft survival, was adversely affected by both pre-existing diabetes and by PTDM, particularly in those with an age less than 55 yr.

Outcome for arterio-venous fistula at the elbow for haemodialysis.

BACKGROUND: Few studies have examined the outcome of arterio-venous fistulas (AVF) at the elbow for haemodialysis. METHODS: All AVFs at the elbow created between 1994 and 1998 were identified retrospectively from case notes and the computerised database. Patients were followed until fistula failure, death, or for a minimum of 6 months until June 1999. Life table analysis and Kaplan-Meier actuarial curves with the log rank test were used to assess the influence of age, sex, diabetes, hypertension, heart disease, cerebrovascular disease, use of erythropoietin, aspirin or warfarin, previous insertion of subclavian vein catheter and the levels of haemoglobin and serum albumin on long-term AVF survival. RESULTS: A total of 137 AVFs (primary procedure in 84 and as a secondary procedure in 53 cases) at the elbow were performed in 130 patients; 7 patients had AVFs attempted at both elbows. The mean age was 56.57 yr with a mean follow-up of 48.54 months. Twenty-two patients died with a functioning AVF, while 7 patients also with a functioning AVF received a renal transplant. Overall 74% of AVF were patent at the end of 1 yr, while 22.5% failed or did not mature immediately after the procedure. Two patients had their AVFs tied off due to steal syndrome. Of the various factors known to affect long-term survival of AVF in patients receiving haemodialysis, only plasma albumin > 35 g/L was associated with poorer long-term patency in our study. CONCLUSION: Our report supports the view that AVF at the elbow may obviate the disadvantages of AVF at the wrist in elderly patients, females and in diabetics. In this group of patients it may be preferable to create a primary AVF at the elbow rather than the wrist. Patients who have a failed attempt at creating an AVF at the wrist should undergo AVF at the elbow before the placement of a synthetic graft. This strategy will result in saving time and avoid multiple operations. There may also be a reduction in the use of synthetic grafts resulting in cost savings and avoiding the complications associated with synthetic grafts.

Validation procedures for the Hamilton Thorne Integrated Visual Optical System sperm and cell analyzer.

The Hamilton Thorne Integrated Visual Optical System (IVOS) analyzer is a combined internal optical and computer system widely applied to laboratory animals, such as rat, rabbit, and canine, sperm in reproductive toxicology. It measures sperm motility, progressive motility, velocity, motion parameters, and concentration. The system is specially designed to facilitate on-site validation. Digital encoding allows image storage with absolute replay fidelity for later reexamination, enabling on-site validation complying with Good Laboratory Practices. A NIST-certified scale provides the length standard on which validation is based. Sperm typically move in wavy tracks, which must be characterized and validated. Playback of exact sperm tracks allows visual validation of sperm head position, given as Cartesian coordinates, and visual determination of motility from the playback screen. A cursor checks coordinate values, and manual confirmation of sperm motion parameters may be performed directly from the validated coordinates. Agreement to within 0.2% is obtained between manual and IVOS computation. Concentration is determined using a specific DNA stain that enables discrimination between sperm and somatic cell nuclei. The IVOS concentration of sperm nuclei in homogenized rat testis and cauda epididymis has been determined to be within 5% of manual hemacytometer counts of the same homogenate.

Cat-scratch disease--Connecticut, 1992-1993.

A prospective population-based surveillance system was established to characterize the epidemiology of cat-scratch disease (CSD) among residents of Connecticut who were reported to the state health department with a diagnosis of suspected CSD. During 1992 and 1993, 246 persons met the case definition, for an average statewide annual incidence of 3.7/100,000 persons. The median age of patients with CSD was 14 years (range, 1-64), and 52% were female. The age-specific attack rate was highest among persons < 10 years of age (9.3/100,000) and decreased with increasing age. Symptoms in addition to adenopathy were noted by 74% of case-patients. Eleven percent of all case-patients were hospitalized. There were no deaths. Most patients with clinically diagnosed CSD developed an immunologic response to Bartonella species. Our data suggest that although CSD is primarily a disease of younger persons, the age spectrum is wider than was commonly appreciated.

Cat scratch disease in Connecticut. Epidemiology, risk factors, and evaluation of a new diagnostic test.

BACKGROUND: Although cat scratch disease is commonly diagnosed in patients who have unexplained regional lymphadenopathy after encounters with cats, its epidemiology and the risk factors for disease are not clearly defined, and there is no generally accepted diagnostic test. METHODS: We conducted a physician survey to identify cases of cat scratch disease occurring over a 13-month period in cat owners in Connecticut. We interviewed both the patients (or their parents) and controls matched for age who owned cats. Serum from the patients was tested for antibodies to Rochalimaea henselae with a new, indirect fluorescent-antibody test. RESULTS: We identified 60 patients with cat scratch disease and 56 age-matched subjects. Patients were more likely than controls to have at least one pet kitten 12 months old or younger (odds ratio, 15), to have been scratched or bitten by a kitten (odds ratio, 27), and to have had at least one kitten with fleas (odds ratio, 29). A conditional logistic-regression analysis found that in kitten-owning households, patients were more likely than controls to have been scratched or bitten by a cat or kitten (odds ratio, 12.4; 95 percent confidence interval, 1.0 to 150). Of 45 patients, 38 had serum samples with titers of 1:64 or higher for antibody to R. henselae, as compared with 4 of 112 samples from controls (P < 0.001). The positive predictive value of the serologic test was 91 percent. Of 48 serum samples from patients' cats, 39 were positive for antibodies to R. henselae, as compared with positive samples from 11 of 29 control cats (P < 0.001). CONCLUSIONS: Cat scratch disease is strongly associated with owning a kitten, and fleas may be involved in its transmission. The serologic test for rochalimaea may be useful diagnostically, and our results suggest an etiologic role for this genus.

A field study of the fertility of transported equine semen.

A field trial of artificial insemination in horses with transproted, chilled semen was conducted using a specially designed container which permitted a controlled, slow initial rate of cooling (-0.3 degrees C/min) and maintenance of a final temperature of 4 degrees -6 degrees C for more than 36 hrs. Forty-six mares in 23 states were inseminated with semen from three German Warmblood stallions standing at stud in Hamilton, Massachusetts. A third-cycle conception rate of 91% was obtained.

Characterization of the non-permissive infection of rabbit cornea cells by vesicular stomatitis virus.

Rabbit cornea cells (RC-60) restrict the reproduction of vesicular stomatitis virus (VSV) (Thacore & Youngner, 1975). In cells infected with VSV alone, an inhibition in the synthesis of VSV genome RNA is observed. A number of parameters which could affect virus RNA synthesis have been examined: virus transcription and post-transcriptional modification, translation, modification of proteins and migration of the G protein to the surface of the cell; they all appear to be normal, although somewhat diminished, in the restricted system. In these cells, therefore, it is the replication of VSV RNA that is directly inhibited, although limited synthesis of both (+) and (-) strand genome length RNA does occur. When the cells are co-infected with rabbit poxvirus (RPV) as a helper virus, however, VSV production is normal. Our studies suggest that RPV plays a role in the maturation as well as in the replication of VSV RNA in RC-60 cells. Certain mutants of RPV have been found to lack the helper function and are unable to convert the RC-60 cells into a permissive host for VSV. These mutants should facilitate the elucidation of the mechanism by which RPV is able to overcome the restriction in these cells.

CO(2) (10.6-microm) atmospheric propagation enhancement due to off-line center tuning.

A new analysis is presented for the atmospheric transmission of the CO(2)(P-20) line, which includes pressure shift, bleaching, and tuning off-line center. The results indicate that absorption is negligible above 25 km for an atmospheric CO(2) laser, even at line center, with the resulting transmission equal to 0.5 from sea level and 0.75 from 2.5 km altitude, midlatitude summer. Cavity tuning of about 0.1 cm(-1) produces a transmission of 0.97 from 2.5 km, with a corresponding large decrease in thermal blooming, but with little decrease of cavity efficiency for a well-saturated atmospheric pressure cavity, since the linewidth of the latter is considerably larger than that of the atmosphere.

Transmission at lambda = 10.6-mum wavelength through the upper atmosphere.

An analytic model of atmospheric bleaching at 10.6 umicrom is derived from analysis of the kinetic equations for the CO(2)-N(2)-H(2)O system. The case of upward-directed CO(2) laser beams is of particular interest, and values of local absorptance and total absorption integrated along beam path are given. At intensities 10(6)-10(7) W cm(-2) thermal blooming of the laser beam is greatly reduced due to bleached absorption.

Power plants: effects of chlorination on estuarine primary production.

Steam electric stations may reduce primary production of cooling water by 91 percent as a result of chlorine applications for control of fouling organisms. Bacterial densities and concentrations of chlorophyll a are also reduced. Slight stimulation of production may occur in the absence of chlorination. Based on the available supply of "new" water, we calculate a maximum loss of primary production of 6.6 percent for the adjacent tidal segment of the Patuxent River.