Contraceptive method use among HIV-positive women in a US urban outpatient clinic: an exploratory cross-sectional study.

OBJECTIVE(S): Effective contraceptive method use is important for HIV-positive women to meet fertility goals, prevent unintended pregnancy and reduce risk of vertical HIV transmission. Our objective was to evaluate factors associated with HIV-positive women's contraceptive method use at last coitus defined as more effective [Tier 1 and 2 methods (T1/2)] versus less effective [Tier 3 or no method (T3/none)] by the US Medical Eligibility Criteria for contraception use. STUDY DESIGN: HIV-positive women, recruited from an HIV clinic in Atlanta, Georgia, between 2013 and 2014, completed a survey of demographic, clinical and reproductive health characteristics surrounding contraception. We examined the relationship between survey responses and contraceptive method use at last coitus using χ2 tests and multivariate logistic regression. RESULTS: Thirty-one percent of this HIV-positive and predominantly African-American (90%) cohort reported usage of T1/2 methods. T1/2 methods use was higher among younger women [adjusted odds ratio (aOR)=.90, p=.008] and those in noncommitted relationships (aOR =.32, p=.027). Only 21% reported dual method use at last intercourse. Fifty-three percent and 31% reported having heard of the intrauterine device and implant, respectively. Misconceptions about contraception were common. CONCLUSIONS: The use of T1/2 methods was more common in this cohort than in the general African-American population, but overall use and dual method use can still be improved, particularly among older women and those in noncommitted relationships. IMPLICATIONS: As this population had low awareness and usage of T1/2 methods and expressed many misconceptions, reoccurring contraceptive counseling may be helpful. Providers should address patient-level barriers, pregnancy intentions, and the importance of dual method and T1/2 method use.

Hepatitis A virus (HAV) proteinase 3C inhibits HAV IRES-dependent translation and cleaves the polypyrimidine tract-binding protein.

Hepatitis A virus (HAV) infection is still an important issue worldwide. A distinct set of viruses encode proteins that enhance viral cap-independent translation initiation driven by an internal ribosome entry site (IRES) and suppress cap-dependent host translation. Unlike cytolytic picornaviruses, replication of HAV does not cause host cell shut off, and it has been questioned whether HAV proteins interfere with its own and/or host translation. HAV proteins were coexpressed in Huh-7 cells with reporter genes whose translation was initiated by either cap-dependent or cap-independent mechanisms. Among the proteins tested, HAV proteinase 3C suppressed viral IRES-dependent translation. Furthermore, 3C cleaved the polypyrimidine tract-binding protein (PTB) whose interaction with the HAV IRES had been demonstrated previously. The combined results suggest that 3C-mediated cleavage of PTB might be involved in down-regulation of viral translation to give way to subsequent viral genome replication.

Forward genetic screen of mouse reveals dominant missense mutation in the P/Q-type voltage-dependent calcium channel, CACNA1A.

Dominant mutations of the P/Q-type Ca(2+) channel (CACNA1A) underlie several human neurological disorders, including episodic ataxia type 2, familial hemiplegic migraine 1 (FHM1) and spinocerebellar ataxia 6, but have not been found previously in the mouse. Here we report the first dominant ataxic mouse model of Cacna1a mutation. This Wobbly mutant allele of Cacna1a was identified in an ethylnitrosourea (ENU) mutagenesis dominant behavioral screen. Heterozygotes exhibit ataxia from 3 weeks of age and have a normal life span. Homozygotes have a righting reflex defect from postnatal day 8 and later develop severe ataxia and die prematurely. Both heterozygotes and homozygotes exhibit cerebellar atrophy with focal reduction of the molecular layer. No obvious loss of Purkinje cells or decrease in size of the granule cell layer was observed. Real-time polymerase chain reaction revealed altered expression levels of Cacna1g, Calb2 and Th in Wobbly cerebella, but Cacna1a messenger RNA and protein levels were unchanged. Positional cloning revealed that Wobbly mice have a missense mutation leading to an arginine to leucine (R1255L) substitution, resulting in neutralization of a positively charged amino acid in repeat III of voltage sensor segment S4. The dominance of the Wobbly mutation more closely resembles patterns of CACNA1A mutation in humans than previously described mouse recessive mutants (tottering, leaner, rolling Nagoya and rocker). Positive-charge neutralization in S4 has also been shown to underlie several cases of human dominant FHM1 with ataxia. The Wobbly mutant thus highlights the importance of the voltage sensor and provides a starting point to unravel the neuropathological mechanisms of this disease.

Molecular genetics of the early development of hindbrain serotonergic neurons.

The serotonergic (5HT) system plays a key role in modulating behaviors, such as appetite and anxiety and has been implicated in many human disorders of mood and mind. Recent studies have begun to identify the signaling molecules and transcriptional cascades governing 5HT neuron development in the hindbrain. Already at early stages, local differences in requirements of 5HT neuron development have become apparent. These studies point toward cryptic heterogeneity amongst 5HT neurons and suggest that 5HT neuron determination and differentiation may be more flexible and less absolute biologic processes than might have been expected. Ultimately, the intrinsic heterogeneity and environmental sensitivity of 5HT neurons may help explain the variability observed in some human behavioral disorders, such as autism spectrum disorder, and the less predictable behavioral consequences of fetal alcohol syndrome.

Gene-trap mutagenesis: past, present and beyond.

Although at least 35,000 human genes have been sequenced and mapped, adequate expression or functional information is available for only approximately 15% of them. Gene-trap mutagenesis is a technique that randomly generates loss-of-function mutations and reports the expression of many mouse genes. At present, several large-scale, gene-trap screens are being carried out with various new vectors, which aim to generate a public resource of mutagenized embryonic stem (ES) cells. This resource now includes more than 8,000 mutagenized ES-cell lines, which are freely available, making it an appropriate time to evaluate the recent advances in this area of genomic technology and the technical hurdles it has yet to overcome.

A fatigue life analysis of small fragment screws.

OBJECTIVES: To conduct a comparative fatigue analysis of several commonly used small fragment screws. DESIGN: Biomechanical laboratory study. SETTING: Research laboratory. MAIN OUTCOME MEASUREMENTS: A fatigue life analysis of seven different types of small fragment screws was conducted using a Wohler fatigue-testing machine. Four different types of 3.5-millimeter cortical screws were subjected to fatigue analysis. These included solid stainless steel screws from Synthes Ltd. (core diameter 2.4 millimeters), Zimmer Inc. (core diameter 2.4 millimeter), and Smith and Nephew Richards Inc. (core diameter 2.4 millimeters) and cannulated stainless steel screws from Synthes Ltd. (core diameter 2.5 millimeters). In addition, three types of 4.0-millimeter cancellous screws were tested. These included stainless steel screws from Synthes Ltd. (core diameter 1.9 millimeters), titanium screws from Synthes Ltd. (core diameter 2.0 millimeters), and titanium alloy screws from DePuy-Ace (core diameter 2.8 millimeters). Fatigue lives, as reflected by mean cycles to failure, were compared. RESULTS: The four types of cortical screws had longer fatigue lives than the Synthes cancellous screws did ( p < 0.001) but shorter fatigue lives than the DePuy-Ace cancellous screws did ( p < 0.0001). Among the cortical screws, the cannulated and solid Synthes screws and the solid Zimmer screws did not differ statistically. The Smith and Nephew Richards cortical screws failed at statistically fewer cycles than the Synthes solid and cannulated cortical screws did ( p < 0.003) but did not statistically differ from the Zimmer screws. The DePuy-Ace titanium alloy cancellous screw had the longest fatigue life of the tested implants by a large margin ( p < 0.0001). The Synthes pure titanium and stainless steel cancellous screws did not significantly differ. CONCLUSIONS: This analysis supports core diameter as the principal factor determining fatigue life as the results paralleled implant geometry. This design modification to improve bending and fatigue strength may come at a price to pullout strength, however, because of a decreased major-to-minor diameter and increased pitch. Cortical screws differed in fatigue performance despite identical dimensions, presumably highlighting the importance of implant processing and machining. Cannulated cortical screws performed well relative to solid screws, thereby supporting their clinical use. Pure titanium and stainless steel cancellous screws performed similarly in fatigue despite differing material properties, presumably because of geometric design differences. This report highlights some of the differences in the in vitro fatigue performance among several commonly used small fragment screws.

Variability signatures distinguish verbal from nonverbal counting for both large and small numbers.

Humans appear to share with animals a nonverbal counting process. In a nonverbal counting condition, subjects pressed a key a numeral-specified number of times, while saying "the" at every press. The mean number of presses increased as a power function of the target number, with a constant coefficient of variation (c.v.), both within and beyond the proposed subitizing range (1-4 or 5), suggesting small numbers are represented on the same continuum as larger numbers and subject to the same noise process (scalar variability). By contrast, when subjects counted their presses out loud as fast as they could, the c.v. decreased as the inverse square root of the target value (binomial variability instead of scalar variability). The unexpected power-law relation between target value and mean number of presses in nonverbal counting suggests a new hypothesis about the development of the function relating number symbols to mental magnitudes.

Effects of ENU dosage on mouse strains.

The germline supermutagen, N-ethyl-N-nitrosourea (ENU), has a variety of effects on mice. ENU is a toxin and carcinogen as well as a mutagen, and strains differ in their susceptibility to its effects. Therefore, it is necessary to determine an appropriate mutagenic, non-toxic dose of ENU for strains that are to be used in experiments. In order to provide some guidance, we have compiled data from a number of laboratories that have exposed male mice from inbred and non-inbred strains or their F(1) hybrids to ENU. The results show that most F(1) hybrid animals tolerate ENU well, but that inbred strains of mice vary in their longevity and in their ability to recover fertility after treatment with ENU.

Mechanical properties of small fragment screws.

For many years, stainless steel small fragment screws have been produced by one manufacturer. Recently, other implant makers have begun offering similar stainless steel screws. In addition, screw geometry and material composition have been modified in an attempt to produce screws for a wide range of clinical situations. This study compared the mechanical properties of several commonly used small fragment screws. Seven sets of screws were tested mechanically, including three brands of geometrically identical standard stainless steel cortical screws and one brand each of cannulated stainless steel cortical screws, titanium cortical screws, stainless steel cancellous screws, and bioabsorbable polylactic acid screws. Screws from each group were tested for pullout strength, torque to failure, and three-point bending to failure. There were no differences in the mechanical properties of the identical 3.5-mm standard stainless steel cortical screws. No difference in pullout strength was found between the five sets of cortical screws. However, the cancellous screws had 4% to 24% less pullout strength. Torsion tests showed that cannulated stainless steel cortical, titanium cortical screws, stainless steel cancellous screws, and polylactic acid screws failed at significantly less torque than did standard stainless steel cortical screws. Standard stainless steel cortical screws had the highest mean yield point and maximal load at failure of all screws in three-point bending. Other metal screws had lower yield strength and maximal load at failure than did the standard stainless steel cortical screws, and polylactic acid screws had the least bending strength.

Regulation of mouse lens fiber cell development and differentiation by the Maf gene.

Maf is a basic domain/leucine zipper domain protein originally identified as a proto-oncogene whose consensus target site in vitro, the T-MARE, is an extended version of an AP-1 site normally recognized by Fos and Jun. Maf and the closely related family members Neural retina leucine zipper (Nrl), L-Maf, and Krml1/MafB have been implicated in a wide variety of developmental and physiologic roles; however, mutations in vivo have been described only for Krml1/MafB, in which a loss-of-function causes abnormalities in hindbrain development due to failure to activate the Hoxa3 and Hoxb3 genes. We have used gene targeting to replace Maf coding sequences with those of lacZ, and have carried out a comprehensive analysis of embryonic expression and the homozygous mutant phenotype in the eye. Maf is expressed in the lens vesicle after invagination, and becomes highly upregulated in the equatorial zone, the site at which self-renewing anterior epithelial cells withdraw from the cell cycle and terminally differentiate into posterior fiber cells. Posterior lens cells in Maf(lacZ) mutant mice exhibit failure of elongation at embryonic day 11.5, do not express (&agr;)A- and all of the (beta)-crystallin genes, and display inappropriately high levels of DNA synthesis. This phenotype partially overlaps with those reported for gene targeting of Prox1 and Sox1; however, expression of these genes is grossly normal, as is expression of Eya1, Eya2, Pax6, and Sox2. Recombinant Maf protein binds to T-MARE sites in the (alpha)A-, (beta)B2-, and (beta)A4-crystallin promoters but fails to bind to a point mutation in the (alpha)A-crystallin promoter that has been shown previously to be required for promoter function. Our results indicate that Maf directly activates many if not all of the (beta)-crystallin genes, and suggest a model for coordinating cell cycle withdrawal with terminal differentiation.

Rural hospitals and the local economy: a needed extension and refinement of existing empirical research.

The relationship between the health care sector and the rural economy is of increasing importance. Much additional research is needed to fully understand this relationship and to address some of the limitations of the modest amount of research that already exists. In this study, data from Nebraska were used to create a four-part typology of rural hospitals. Input-output analysis was used to assess the economic effects of each type of hospital on the local economy and to simulate the effects of three different changes or scenarios: an increase or decrease in hospital utilization; the elimination of local purchases of nonlabor inputs; and a change in the mix or configuration of services provided. While the hospital is an important contributor to local economies, this contribution is not constant across hospital types. The total job-related effects ranged from 77 jobs for the smallest type of rural hospital to 1,332 for the largest type. Service and trade (retail plus wholesale) are the two sectors of the local economy most heavily influenced by the presence of a hospital. In today's changing and challenging environment, there is a great need for researchers to create and evaluate the economic effects of a variety of relevant and realistic scenarios (other than hospital closure).

Human KRML (MAFB): cDNA cloning, genomic structure, and evaluation as a candidate tumor suppressor gene in myeloid leukemias.

Members of the MAF family of basic region/leucine zipper transcription factors can affect transcription in either a positive or a negative fashion, depending on their partner protein(s) and the context of the target promoter. The KRML (MAFB) transcriptional regulator plays a pivotal role in regulating lineage-specific hematopoiesis by repressing ETS1-mediated transcription of erythroid-specific genes in myeloid cells. In previous studies, we mapped the human KRML gene within a genomic contig on human chromosome 20, bands q11.2-q13.1. We have isolated the human cDNA containing the full-length predicted open reading frame (ORF). Multiple KRML transcripts of approximately 1.8 and approximately 3 kb, which differ in the length of the 3' untranslated region, are ubiquitously expressed in hematopoietic tissues and encode a protein with 323 amino acids (MW 35,832). The protein has 84% identity and 92% similarity to the murine protein. The ORF of the human KRML gene contains no introns, and the gene spans approximately 3 kb. KRML maps within the smallest commonly deleted segment in malignant myeloid disorders characterized by a deletion of 20q; however, we detected no mutations of KRML in leukemia cells with loss of 20q. Thus, KRML is unlikely to be involved in the pathogenesis of malignant myeloid disorders characterized by abnormalities of chromosome 20.

Expression of Zkrml2, a homologue of the Krml1/val segmentation gene, during embryonic patterning of the zebrafish (Danio rerio).

We have identified Zkrml2, a novel homologue of the segmentation gene Krml/val in zebrafish (Danio rerio). Zkrml2 shows 72% and 92% identity in its basic leucine zipper domain with mouse Krml1 and zebrafish val, respectively. Zkrml2 is expressed coincident with MyoD throughout the somites starting at the three somite stage, becomes restricted to the dermomyotome, and subsequently disappears. Transient expression is also detected in the reticulospinal and oculomotor neurons. Zkrml2 maps to the Oregon linkage group 11 (Boston Linkage group 14) with no mapped zebrafish mutations nearby.

Conserved and distinct roles of kreisler in regulation of the paralogous Hoxa3 and Hoxb3 genes.

During anteroposterior patterning of the developing hindbrain, the anterior expression of 3' Hox genes maps to distinct rhombomeric boundaries and, in many cases, is upregulated in specific segments. Paralogous genes frequently have similar anterior boundaries of expression but it is not known if these are controlled by common mechanisms. The expression of the paralogous Hoxa3 and Hoxb3 genes extends from the posterior spinal cord up to the rhombomere (r) 4/5 boundary and both genes are upregulated specifically in r5. However, in this study, we have found that Hoxa3 expression is also upregulated in r6, showing that there are differences in segmental expression between paralogues. We have used transgenic analysis to investigate the mechanisms underlying the pattern of segmental expression of Hoxa3. We found that the intergenic region between Hoxa3 and Hoxa4 contains several enhancers, which summed together mediate a pattern of expression closely resembling that of the endogenous Hoxa3 gene. One enhancer specifically directs expression in r5 and r6, in a manner that reflects the upregulation of the endogenous gene in these segments. Deletion analysis localized this activity to a 600 bp fragment that was found to contain a single high-affinity binding site for the Maf bZIP protein Krml1, encoded by the kreisler gene. This site is necessary for enhancer activity and when multimerized it is sufficient to direct a kreisler-like pattern in transgenic embryos. Furthermore the r5/r6 enhancer activity is dependent upon endogenous kreisler and is activated by ectopic kreisler expression. This demonstrates that Hoxa3, along with its paralog Hoxb3, is a direct target of kreisler in the mouse hindbrain. Comparisons between the Krml1-binding sites in the Hoxa3 and Hoxb3 enhancers reveal that there are differences in both the number of binding sites and way that kreisler activity is integrated and restricted by these two control regions. Analysis of the individual sites revealed that they have different requirements for mediating r5/r6 and dorsal roof plate expression. Therefore, the restriction of Hoxb3 to r5 and Hoxa3 to r5 and r6, together with expression patterns of Hoxb3 in other vertebrate species suggests that these regulatory elements have a common origin but have later diverged during vertebrate evolution.

The changing landscape of health care financing and delivery: how are rural communities and providers responding?

Rural communities have not kept pace with the recent dramatic changes in health care financing and organization. However, the Medicare provisions in the Balanced Budget Act of 1997 will require rural providers to participate in the new systems. Case studies revealed the degree of readiness for change in six rural communities and charted their progress along a continuum, as reflected in three sets of activities: the development of networking; the creation of new strategies for managing patient care; and the adoption of new methods for contracting with health insurers. Some communities had constructed highly integrated systems, whereas others were just beginning to change their billing practices; a few were signing contracts for capitated care, in contrast to those that were resisting discounts in current fee structures. These six rural areas still have considerable ground to cover before their health care organization and financing reach the levels achieved by urban communities.

Equivalence in the genetic control of hindbrain segmentation in fish and mouse.

The vertebrate hindbrain is subdivided into a series of rhombomeres whose segmental organization serves to pattern the architecture and innervation of the developing head. The zebrafish gene valentino is required cell-autonomously in the development of rhombomeres 5 and 6, and valentino mutants lack visible hindbrain segmentation caudal to the r3/4 boundary (Moens, C. B., Yan, Y.-L., Appel, B., Force, A. G., and Kimmel, C. B. (1996) Development 122, 3981-3990). Here we show that valentino is the zebrafish homologue of the mouse segmentation gene kreisler, which encodes a bZip transcription factor. The valentino gene is expressed in a manner consistent with its proposed role in subdividing rhombomeres 5 and 6 from their common precursor 'proto-segment' in the presumptive hindbrain, a process that we also demonstrate is reflected in the normal order of appearance of rhombomere boundaries. As well as having similar phenotypes with respect to visible hindbrain segmentation and patterns of marker gene expression, valentino and kreisler mutants have similar pharyngeal arch and inner ear defects, consistent with a conserved role for this gene in hindbrain segmentation and in patterning of the head periphery.

Segmental regulation of Hoxb-3 by kreisler.

Hox genes control regional identity during segmentation of the vertebrate hindbrain into rhombomeres. Here we use transgenic analysis to investigate the upstream mechanisms for regulation of Hoxb-3 in rhombomere(r)5. We identified enhancers from the mouse and chick genes sufficient for r5-restricted expression. Sequence comparisons revealed two blocks of similarity (of 19 and 45 base pairs), which each contain in vitro binding sites for the kreisler protein (Kmrl1), a Maf/b-Zip protein expressed in r5 and r6 (ref. 4). Both sites are required for r5 activity, suggesting that Hoxb-3 is a direct target of kreisler. Multimers of the 19-base-pair (bp) block recreate a Krml1-like pattern in r5/r6, but the 45-bp block mediates expression only in r5. Therefore elements within the 45-bp block restrict the response to Krml1. We identified additional sequences that contain an Ets-related activation site, required for both the activation and restriction to r5. These studies demonstrate that Krml1 directly activates expression of Hoxb-3 in r5 in combination with an Ets-related activation site, and suggest that kreisler plays a primary role in regulating segmental identity through Hox genes.

The mouse segmentation gene kr encodes a novel basic domain-leucine zipper transcription factor.

The mouse kreisler (kr) mutation causes segmentation abnormalities in the caudal hindbrain and defective inner ear development. Based on an inversion discovered in the original kr allele, we selected a candidate cDNA highly expressed in the developing caudal hindbrain. This cDNA encodes a basic domain-leucine zipper (bZIP) transcription factor and was confirmed to represent the kr gene by analysis of a second kr allele, generated by chemical mutagenesis, in which a serine is substituted for an asparagine residue conserved in the DNA-binding domain of all known bZIP family members. The identity, expression, and mutant phenotype of kr indicate an early role in axial patterning and provide insights into the molecular and embryologic mechanisms that govern hindbrain and otic development.

An expert panel approach to assessing the rural implications of health care reform: the case of the Health Security Act.

The policy arena is hungry for objective information regarding the potential effects of comprehensive national and state health care reform. Such information reduces the dependence of policy-makers on information generated solely by advocacy groups and serves as a checkpoint for such information. Unfortunately, the academic community is often unable to mobilize its resources quickly enough to help meet this information need. This article describes one model for overcoming this difficulty. When the time frame is especially short, academic expertise can be brought together in the form of an expert panel. However, for such an approach to be effective, it must be carefully configured and orchestrated. Critical ingredients include much preparatory groundwork, a well-defined framework and methodology for conducting the policy analysis, and a professional facilitator. The Rural Policy Research Institute used such an approach to analyze President Clinton's Health Security Act shortly after the initial blueprint was released (but before the legislative language was released). The consensus of the expert panel was that the Health Security Act would, on balance, represent an improvement over today's rural reality. However, a number of troubling aspects were noted. First, the Act's emphasis on primary care and nonphysician providers is a double-edged sword. While these are precisely the types of providers needed in rural areas, the short-run effect may be to create increased competition for such providers from urban areas.(ABSTRACT TRUNCATED AT 250 WORDS)