Protective immunity does not correlate with the hierarchy of virus-specific cytotoxic T cell responses to naturally processed peptides

Infection of C57BL/6 mice with lymphocytic choriomeningitis virus (LCMV) stimulates major histocompatibility complex class I-restricted cytotoxic T cells (CTLs), which normally resolve the infection. Three peptide epitopes derived from LCMV have been shown to bind the mouse class I molecule H-2 Db and to stimulate CTL responses in LCMV-infected mice. This report describes the identity and abundance of each CTL epitope after their elution from LCMV-infected cells. Based on this information, peptide abundance was found to correlate with the magnitude of each CTL response generated after infection with LCMV. Subsequent experiments, performed to determine the antiviral capacity of each CTL specificity, indicate that the quantitative hierarchy of CTL activity does not correlate with the ability to protect against LCMV infection. This report, therefore, indicates that immunodominant epitopes should be defined, not only by the strength of the CTL response that they stimulate, but also by the ability of the CTLs to protect against infection.     

IFN-tau: a novel subtype I IFN1. Structural characteristics, non-ubiquitous expression, structure-function relationships, a pregnancy hormonal embryonic signal and cross-species therapeutic potentialities

IFN-tau (IFN-tau) constitutes a new class of type I IFN which is not virus-inducible, unlike IFN-alpha and IFN-beta, but is constitutively produced by the trophectoderm of the ruminant conceptus during a very short period in early pregnancy. It plays a pivotal role in the mechanisms of maternal recognition of pregnancy in ruminants and it displays high antiviral and antiproliferative activities across species with a prominent lack of cytotoxicity at high concentrations in vitro in cell culture and possibly in vivo. It exhibits high antiretroviral activity against HIV and exhibits immunosuppressive activity in a multiple sclerosis model and reduces embryo and fetal mortality by stimulation of IL-10 production. In this review all the biochemical and para-hormonal properties of this novel IFN-tau are described in detail: structural characteristics of proteins and genes, trophoblast expression, regulation of its expression, structure of its gene promoter, its absence in human species and in non-ruminant animals, the evolution of the IFN-tau genes, its structure-function relationships with its three-dimensional structure, structural localization of biological activities, its lack of cytotoxicity and its receptor. Surprisingly, for an IFN, IFN-tau is also a pregnancy-embryonic signal with paracrine antiluteolytic activity. In order to maintain luteal progesterone secretion, IFN-tau inhibits PGF-2alpha pulsatile secretion and oxytocin uterine receptivity in early pregnancy. It is believed to suppress pulsatile release of endometrial PGF-2alpha by preventing oxytocin and estrogen receptor expression. Additionally, it directly regulates prostaglandin metabolism and possibly the PGE:PGF-2alpha ratio.     

Variation in epinephrine and cortisol excretion rates associated with behavior in an Australian Aboriginal community

OBJECTIVE: To compare the effectiveness of three antibiotic regimens for the treatment of acute pyelonephritis in pregnancy. METHODS: One hundred seventy-nine pregnant women earlier than 24 weeks' gestation who had acute pyelonephritis were randomized to 1) intravenous (i.v.) ampicillin and gentamicin, 2) i.v. cefazolin, or 3) intramuscular ceftriaxone. All participants then completed 10-day courses of oral cephalexin after primary treatment. A urine culture was performed on admission and 5-14 days after completion of therapy. Surveillance for persistent or recurrent infection and obstetric complications continued until delivery. On the basis of a two-sided hypothesis test and with alpha = .025, 60 subjects were needed in each group for statistical power greater than 80% to detect a difference between ceftriaxone and other antibiotics if hospital length of stay differed by 1 or more days. RESULTS: The treatment groups were similar in age, parity, temperature, gestational age, and initial white blood cell count. There were no statistically significant differences in length of hospitalization, hours until becoming afebrile, days until resolution of costovertebral angle tenderness, or infecting organism. There were no statistically significant differences in birth outcomes between the three groups. The average (standard deviation) age at delivery was 38.8 +/- 3.6 weeks. The average birth weight was 3274 +/- 523 g. Eleven (6.9%) of 159 subjects delivered prematurely. Escherichia coli was the most common uropathogen isolated (137 of 179, 76.5%). Blood cultures were positive for organisms in 15 cases (8.4%). At follow-up examination within 2 weeks of initial therapy, eight (5.0%) of 159 subjects had urine cultures positive for organisms. Ten women (6.3%) had cultures positive for organisms later in their antepartum course, and 10 other participants (6.3%) developed recurrent pyelonephritis. CONCLUSION: There are no significant differences in clinical response to antimicrobial therapy or birth outcomes among subjects treated with ampicillin and gentamicin, cefazolin, or ceftriaxone for acute pyelonephritis in pregnancy before 24 weeks' gestation.     

Biologically active Rep proteins of adeno-associated virus type 2 produced as fusion proteins in Escherichia coli

Four Rep proteins are encoded by the human parvovirus adeno-associated virus type 2 (AAV). The two largest proteins, Rep68 and Rep78, have been shown in vitro to perform several activities related to AAV DNA replication. The Rep78 and Rep68 proteins are likely to be involved in the targeted integration of the AAV DNA into human chromosome 19, and the full characterization of these proteins is important for exploiting this phenomenon for the use of AAV as a vector for gene therapy. To obtain sufficient quantities for facilitating the characterization of the biochemical properties of the Rep proteins, the AAV rep open reading frame was cloned and expressed in Escherichia coli as a fusion protein with maltose-binding protein (MBP). Recombinant MBP-Rep68 and MBP-Rep78 proteins displayed the following activities reported for wild-type Rep proteins when assayed in vitro: (i) binding to the AAV inverted terminal repeat (ITR), (ii) helicase activity, (iii) site-specific (terminal resolution site) endonuclease activity, (iv) binding to a sequence within the integration locus for AAV DNA on human chromosome 19, and (v) stimulation of radiolabeling of DNA containing the AAV ITR in a cell extract. These five activities have been described for wild-type Rep produced from mammalian cell extracts. Furthermore, we recharacterized the sequence requirements for Rep binding to the ITR and found that only the A and A' regions are necessary, not the hairpin form of the ITR.     

Enhanced intestinal adenomatous polyp formation in Pms2-/-;Min mice

Analysis of two human familial cancer syndromes, hereditary nonpolyposis colorectal cancer and familial adenomatous polyposis, indicates that mutations in either one of four DNA mismatch repair gene homologues or the adenomatous polyposis coli (APC) gene, respectively, are important for the development of colorectal cancer. To further investigate the role of DNA mismatch repair in intestinal tumorigenesis, we generated mice with mutations in both Apc and the DNA mismatch repair gene, Pms2. Whereas Pms2-deficient mice do not develop intestinal tumors, mice deficient in Pms2 and heterozygous for Min, an allele of Apc, develop approximately three times the number of small intestinal adenomas and four times the number of colon adenomas relative to Min and Pms2+/-;Min mice. Although Pms2 deficiency clearly increases adenoma formation in the Min background, histological analysis indicated no clear evidence for progression to carcinoma.     

A phorbol ester binding domain of protein kinase C gamma. High affinity binding to a glutathione-S-transferase/Cys2 fusion protein

Cysteine-rich regions of protein kinase C (PKC) are implicated in diacylglycerol-dependent regulation of kinase activity. The second cysteine-rich region (residues 92-173) of PKC gamma was expressed as a fusion protein with glutathione-S-transferase in Escherichia coli and purified to homogeneity by affinity chromatography. This fusion protein displayed high affinity phorbol dibutyrate (PDBu) binding (Kd 23 nM). The phosphatidylserine dependence of PDBu binding was highly cooperative with Hill numbers (near 4.5) similar to those previously reported for PKC gamma (Burns, D. J., and Bell, R. M. (1991) J. Biol. Chem. 266, 18330-18338). The fusion protein specifically bound 4 beta-hydroxy-PDBu but not the 4 alpha-stereoisomer. Furthermore, sn-1,2-dioctanoylglycerol (diC8) stereoselectively competed for PDBu binding. The cysteine-rich region was sufficient for association of the fusion protein to liposome preparations containing phosphatidylserine and phosphatidylcholine. Association was significantly enhanced in a stereospecific manner by the presence of PDBu as well as diC8. These results establish that a single cysteine-rich domain (residues 92-173) of PKC gamma contains regions necessary and sufficient for lipid-dependent stereospecific interactions with PDBu and diC8. Furthermore, the region is sufficient to confer translocation of a fusion protein to liposomes in a PDBu- and diC8-dependent fashion. Thus, a single cysteine-rich region of PKC gamma displays many of the properties characteristic of PKC.     

Memorizing and recalling spatial-temporal patterns in an oscillator model of the hippocampus

We describe the model of the hippocampus consisting of interactive oscillators with input from the entorhinal cortex (modulating the main information flow by a theta rhythm) and the septum (a theta rhythm generator). When interconnections between oscillators are allowed to strengthen in an adaptive way, the network can be trained using a series of lessons. This results in a connection matrix that memorizes the temporal sequence of inputs. Presenting one of the lessons to the trained network results in reproduction of the remainder of the sequence. In this paper, we create such a connection matrix, derive from it an appropriate Markov chain and simulate the chain to illustrate its dynamics.     

Accelerated radiotherapy regimen for malignant gliomas using stereotactic concomitant boosts for dose escalation

Parvovirus B19 (PV B19) infection was investigated in 29 pregnant women with fetal hydrops, after exclusion of feto-maternal incompatibility within red blood cell antigens, TORCH infections, feto-maternal hemorrhage and genetics reasons. The active viral infection was detected in 9 women (31%) by PCR amplification of DNA B19; in 2 of them IgM and IgG, in 1 IgM and in 4 IgG antibodies were also present. In 6 women (20%) IgG antibodies were only found, but not IgM and DNA B19, which confirmed infection in the past. In addition in 9 cases DNA B19 was evaluated in the fetal blood. The results in the mothers and their fetuses were concordant (4 positive, 5 negative). Our conclusion is that in nonimmune hydrops fetalis, PV B19 infection should be based on the viral DNA evaluation in the blood of mother (or fetus). IgM antibodies, in time of fetal disorders, might not be detected.     

Increased use of mammography among Hispanic women: baseline results from the NCI Cooperative Group on Cancer Prevention in Hispanic Communities

BACKGROUND: The Healthy People 2000 report set the objective of increasing the percentage of women 40 or older who had ever received a mammogram and clinical breast examination to 80% by the year 2000. The report used a baseline of 36% for all American women and 20% for Hispanic women. The purpose of this study was to compare baseline estimates with data obtained in five Hispanic communities. METHODS: Common survey measures were administered in five studies participating in a National Cancer Institute Cooperative agreement. The surveys evaluated history of mammography in five Hispanic communities in the southwestern Unites States. RESULTS: Across the five communities, the rates of mammography use were significantly higher than the national baseline. Among women 40-49 years of age, 55% had completed mammography (95% confidence interval [CI] = 52%, 57%). Among women 50 years of age or older, 64% had received a mammogram (95% CI = 62%, 66%). Older women (above age 50) were significantly more likely to have completed the test than younger women (younger than age 50), and mammography was obtained less often among women who were uninsured and those who had lower levels of acculturation. CONCLUSIONS: We conclude that the rate of mammography use among Hispanic women has increased significantly over the last few years and that we are on track to reach the goal of 80% mammography compliance for Hispanic women 40 years and older by the year 2000.