Activation of mitogen-activated protein kinase is required for migration and invasion of placental site trophoblastic tumor

Placental site trophoblastic tumor (PSTT) is a gestational neoplasm derived from the extravillous (intermediate) trophoblast of the implantation site. PSTT is characterized by a highly invasive phenotype, but the molecular mechanisms are poorly understood. In this report, we demonstrate that PSTTs expressed the activated (phosphorylated) form of mitogen-activated protein kinase (MAPK) in 84% of cases, whereas the normal extravillous trophoblastic cells did not. To characterize the role of MAPK activation in PSTT, we established the first PSTT cell culture, IST-2, from a surgically resected PSTT. IST-2 cells expressed HLA-G and Mel-CAM but not E-cadherin, an immunophenotype characteristic of PSTT. IST-2 cells were highly motile and invasive in culture as compared to choriocarcinoma JEG-3 cells and normal extravillous trophoblastic cells. Based on wound assay, time-lapse videomicroscopy for cell tracking, and invasion chamber assays, we found that the motility and invasion of IST-2 cells were significantly reduced (P<0.01) after treatment with the MEK inhibitors CI-1040 and PD 59089, which prevent activation of MAPK. In contrast, neither compound had any effect on normal extravillous trophoblastic cells or JEG-3 cells. In conclusion, our findings demonstrate a functional role of MAPK activation in the motility and invasion of PSTT.     

Ligamentary structure of the base of the nail

Summary The authors report the results of 115 dissections of the base of the distal phalanx of fingers and toes. In 85% of cases including hypoplastic supernumerary digits, there is a connective ligament-like structure. It is a dorsal expansion of the lateral ligament of the distal inter-phalangeal joint arising from the intermediate phalanx and ending in the matrix and the lunula. This ligament may have a role in biomechanical strains on the nail. It can explain some dystrophic nails associated with some malpositioned joints in fingers or toes.

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Structure ligamentaire de la base de l'ongle

Résumé Les auteurs rapportent les résultats de 115 dissections portant sur la base de la phalange distale des doigts ou des orteils. Ils retrouvent dans 85 % des cas, y compris sur des doigts hypoplasiques surnuméraires, une formation conjonctive de type ligamentaire. Il s'agit d'une expansion dorsale du ligament latéral de l'articulation interphalangienne distale, naissant de l'extrémité distale de la phalange intermédiaire et se terminant au sein de la matrice et sur la lunule. Ce ligament ostéomatriciel peut jouer un rôle dans la transmission des contraintes biomécaniques sur l'ongle et expliquer les dystrophies unguéales stéréotypées associées à certaines malpositions articulaires des doigts ou des orteils.

     

Minimal progesterone support required for the maintenance of pregnancy in mice

A study of the degree of progesterone support required for the maintenance of various stages of pregnancy was undertaken in mice. Mated females were ovariectomized at various stages of pregnancy and progesterone and oestradiol support provided by s.c. Silastic implants with known release characteristics. In the earliest stages of pregnancy (days 1-5), very low concentrations of progesterone (<25% of normal physiological values) were sufficient to maintain pre-implantation stages and allow implantation. In the immediate post-implantation period (days 5-9), the development of implantation sites and decidualization required considerably higher progesterone support. In mid-pregnancy (days 11-14), progesterone alone could not maintain pregnancy unless present in very high amounts; however, the presence of oestradiol during this period lowered the progesterone requirements to well within the physiological range. This effect of oestradiol started on day 11 but required the level of oestradiol support to be kept within strictly defined limits, with high concentrations inducing abortion. Progesterone alone was able to maintain pregnancy from day 15. These results indicate that the minimal progesterone support required for pregnancy in mice varies considerably at different stages of pregnancy and is at least partly modulated by oestradiol.      

Characterization of hepatitis B virus (Dane particle)

Hepatitis B virions (Dane particles) were purified from the sera of chronic HBsAg carriers by consecutive rate-zonal and isopycnic centrifugations in sucrose gradients using HBsAg, HBcAg and endogenous DNA polymerase activities as specific markers. Purified Dane particles, radiolabelled with Na ¹²⁵I by the chloramine-T procedure, had a higher buoyant density in CsCl (1.28 g/cm³) than unlabelled particles (1.26 g/cm³) and an estimated sedimentation coefficient of 280 s. ¹²⁵I-Dane particles were fully precipitated by anti-HBs and not by anti-HBc sera. Heavy and light density core particles were purified from heavy and light density populations of Dane particles and radioiodinated. The iodinated polypeptides of Dane particles and HBcAg were compared with those of the iodinated 22-nm form of HBsAg by SDS-PAGE. Iodinated Dane particles contained seven polypeptides with molecular weights of 18,000, 23,000, 26,000, 34,000, 43,000, 48,000 and 115,000. Heavy and light core particles contained three polypeptides with molecular weights of 18,000, 25,000 and 37,000.     

Accelerated transmission of Lyme disease spirochetes by partially fed vector ticks.

To determine how rapidly Lyme disease spirochetes (Borrelia burgdorferi) can be transmitted by partially fed vector ticks (Ixodes dammini), attached nymphs were removed from their hosts at various intervals post-attachment and subsequently permitted to re-feed to repletion on noninfected mice. We confirm previous reports that ticks deposit Lyme disease spirochetes in the skin of their hosts mainly after 2 days of attachment. Those that have been removed from a host within this interval can reattach and commence feeding. Spirochete-infected nymphs that have previously been attached to a host for 1 day become infectious to other hosts within another day. Noninfected nymphs acquire infection from spirochete-infected hosts within a day of attachment and become infectious to other hosts 3 to 5 days later. Virtually all ticks transmitted infection when reattaching after first feeding for 2 days. We conclude that partially fed nymphal ticks transmit spirochetal infection more rapidly than do ticks that have never been attached to a host and that infected ticks become infectious before they molt.     

Rapid identification and susceptibility testing using the VITEK(R) 2 system using culture fluids from positive BacT/ALERT(R) blood cultures

BACKGROUND AND PURPOSE: In order to reduce the turnaround time for laboratory diagnosis of bacteremia, the efficacy of identification and antimicrobial susceptibility testing using samples taken directly from positive BacT/ALERT(R) standard aerobic and standard anaerobic blood culture bottles was evaluated. METHODS: 160 positive blood culture bottles were examined and incubated at 35 degrees C in 5% carbon dioxide for 4-24 h, and an aliquot of the culture fluid was Gram stained. Samples containing Gram-negative bacilli were inoculated on VITEK(R) 2 ID-GNB (identification-Gram-negative bacilli) and AST (antimicrobial susceptibility testing)-GN04 cards, and those containing Gram-positive cocci were inoculated on ID-GPC (identification-Gram-positive cocci) and AST-P526 cards. The same samples were also examined by the standard method, involving subculture from positive BacT/ALERT standard blood culture bottles. RESULTS: Eighty seven of 97 Gram-negative bacilli (89.7%) and 21 of 63 Gram-positive cocci (33.3%) were correctly identified to the species level. For antimicrobial susceptibility testing, the direct method had an overall error rate of 5.4% for Gram-negative bacilli, with 0.9% very major, 0.9% major, and 3.6% minor discrepancies compared to the standard method. The overall error rate in antimicrobial susceptibility testing for the 13 Staphylococcus spp. was 10.3%, with 6.0% very major, 2.6% major, and 1.7% minor discrepancies. CONCLUSION: These data suggest that VITEK 2 cards inoculated with samples taken directly from positive Bact/ALERT blood culture bottles would provide acceptable identification and antimicrobial susceptibility testing results for Gram-negative bacilli, but not for Gram-positive cocci. Compared to the standard method, the direct method would reduce turnaround time by at least 24 h.     

Clinical implications of positive tests for antibodies to human immunodeficiency virus type 1 in asymptomatic blood donors

Of 693,000 volunteer blood donors in Washington, D.C., who were screened for infection with human immunodeficiency virus type 1 (HIV-1) from July 1985 through December 1988, 284 tested positive on both enzyme immunoassay and Western blot assay. To determine the clinical importance of confirmed positive test results in asymptomatic blood donors, we followed 156 donors with positive Western blot assays and 80 donors with positive enzyme immunoassays but negative or indeterminate Western blots at 6-month intervals for a mean of 28 months. As compared with Western blot-negative persons, those with positive Western blots were significantly more likely to be black, male, and first-time donors and to have a history of venereal disease, generalized lymphadenopathy on examination, CD4-cell counts lower than 0.4 x 10(9) per liter, IgG levels higher than 18 g per liter, and antibody to hepatitis B core antigen on initial evaluation. In 17 (11 percent) of the Western blot-positive donors, the disease progressed to Class IV (symptomatic disease), according to the Centers for Disease Control system. CD4 counts below 0.2 x 10(9) per liter, IgA levels above 4 g per liter, abnormal proliferative responses to tetanus toxoid, and positive viral cultures were the strongest predictors of disease progression. Among the 80 donors with repeatedly reactive assay results but either negative or indeterminate Western blot assays, there was no evidence of HIV exposure in their histories, physical examinations, or laboratory evaluations, and manifestations of HIV infection developed in none of them. We conclude that a small number of persons with HIV infection continue to donate blood, despite attempts to exclude them, but that donors who test positive on enzyme immunoassay but persistently negative or indeterminate on Western blot assay probably do not represent a risk for the transmission of HIV.     

Role of BCR affinity in T cell dependent antibody responses in vivo

Antibody affinity for antigen is believed to govern B lymphocyte selection during T-dependent immune responses. To examine antibody affinity in T cell dependent immune responses, we compared mice that carry targeted V(H)B1-8 antibody genes with high or low antigen-binding affinity. We found that high- and low-affinity B cells had the same intrinsic capacity to respond to antigen, but in experiments where limiting numbers of high- and low-affinity B cells were mixed in wild-type recipient mice, only the high-affinity B cells accumulated in germinal centers (GCs). In GCs, high-affinity B cells accumulated fewer V(H) somatic mutations than low affinity B cells. This effect was due to selections as the frequency of mutation in noncoding immunoglobulin gene DNA is the same in high- and low- affinity B cells. Thus, B cells recruited to the GC appeared to undergo a fixed mutation program, regardless of initial B cell receptor affinity. We conclude that in addition to the selection that occurs in GCs, stringent selection for high-affinity clones is also imposed in the early stages of the T cell dependent immune response in vivo.     

Prostate adenocarcinoma using Gleason scores correlates with prostate-specific antigen and prostate acid phosphatase measurements.

To evaluate a relationship between Gleason scores of histopathology of prostate carcinoma and concurrent serum prostate-specific antigen (PSA) and prostate acid phosphatase (PAP) values, 65 men with prostate carcinoma were studied. These patients' cumulative Gleason scores were obtained by totaling the primary and secondary patterns, resulting in two groups: 42 patients received high (6-10) and 23 received low (2-5) Gleason scores. Serum PSA and PAP values were measured by radioimmunometric assay 1 to 7 days before surgical procedures or biopsy for prostate carcinoma. Mean serum PSA for patients in the high Gleason score group was 134.39 ng/mL (normal range: 0 to 4), and the mean serum PSA for patients in the low Gleason score group was 23.62 ng/mL. Mean serum PAP for patients with high scores was 28.08 ng/mL (normal range: 0 to 5), and the mean serum PAP for patients with low scores was 18.19 ng/mL. Patients with high Gleason scores showed significantly greater elevation of serum PSA than those with low Gleason scores (P = .047), using two samples to test for groups having unequal variants. Prostate acid phosphatase levels of patients with high scores were not significantly higher than the levels in patients with low scores (P = .60). These results indicate that PSA levels but not PAP levels correlate with Gleason scores.     

Serum PSA and PAP measurements discriminating patients with prostate carcinoma from patients with nodular hyperplasia.

Prostatic specific antigen (PSA) and prostatic acid phosphatase (PAP) are the tumor markers for monitoring disease progression or improvement in patients with prostate adenocarcinoma. The clinical utility of PSA and PAP for early detection of prostate adenocarcinoma, however, requires distinction between prostate adenocarcinoma and prostate nodular hyperplasia. The serum PSA and PAP levels were measured in 20 men with histologically proven prostate adenocarcinoma and 28 men with histologically proven prostate nodular hyperplasia. Patients'' blood samples were collected 1 to 7 days prior to the prostate examination, which included a rectal digital examination, transurethral resection, cytoscopy, and prostate biopsy. Sensitivity, specificity, and predictive values of positive and negative results for the discrimination of prostate adenocarcinoma from prostate nodular hyperplasia were 85%, 89%, 85%, and 29%, respectively, for serum PSA (cutoff level: 10 ng/mL) and 40%, 96%, 89%, and 69%, respectively, for serum PAP (cutoff level: 10 ng/mL). Results indicate that marked elevation of serum PSA suggests prostate adenocarcinoma and that serum PSA can discriminate prostate adenocarcinoma from prostate nodular hyperplasia better than serum PAP.