Minocycline and Diacetyl Minocycline Eye Drops Reduce Ocular Neovascularization in Mice

Purpose

To evaluate the efficacy of minocycline and a novel, modified minocycline analogue that lacks antimicrobial action, diacetyl minocycline (DAM), on choroidal neovascularization (CNV) in mice of both sexes.

Methods

CNV was induced via laser injury in female and male C57BL/6J mice. Minocycline, DAM, or saline was administered via topical eye drops twice a day for 2 weeks starting the day after laser injury. CNV volume was measured using immunohistochemistry labeling and confocal microscopy.

Results

Minocycline reduced lesion volume by 79% (P ≤ 0.0004) in female and male mice. DAM reduced lesion volume by 73% (P ≤ 0.001) in female and male mice. There was no significant difference in lesion volume between minocycline and DAM treatment groups or between female and male mice.

Conclusions

Both minocycline and DAM eye drops significantly reduced laser-induced CNV lesion volume in female and male mice. While oral tetracyclines have been shown to mitigate pathologic neovascularization in both preclinical studies and clinical trials, the present data are the first to suggest that tetracycline derivatives may be effective to reduce pathologic CNV when administered via topical eye drops. However, the action is unrelated to antimicrobial action. Targeted delivery of these medications via eye drops may reduce the potential for systemic side effects.

Translational Relevance

Topical administration of minocycline and/or DAM via eye drops may represent a novel therapeutic strategy for disorders involving pathologic CNV.

Investigation of oral, gastric, and duodenal microbiota in patients with upper gastrointestinal symptoms

Disease-associated alterations of the intestinal microbiota composition, known as dysbiosis, have been well described in several functional gastrointestinal (GI) disorders. Several studies have described alterations in the gastric microbiota in functional dyspepsia, but very few have looked at the duodenum.Here, we explored the upper GI tract microbiota of inpatients with upper GI dyspeptic symptoms, and compared them to achalasia controls, as there is no indication for an esophagogastroduodenoscopy in healthy individuals.We found differences in the microbiota composition at the three sites evaluated (ie, saliva, stomach and duodenum). Changes observed in patients with dyspepsia included an increase in Veillonella in saliva, an oral shift in the composition of the gastric microbiota, and to some degree in the duodenum as well, where an important abundance of anaerobes was observed. Metabolic function prediction identified greater anaerobic metabolism in the stomach microbial community of patients with dyspepsia. Proton pump inhibitor use was not associated with any particular genus. Co-abundance analysis revealed Rothia as the main hub in the duodenum, a genus that significantly correlated with the relative abundance of Clostridium, Haemophilus, and ActinobacillusWe conclude that patients with upper GI symptoms consistent with dyspepsia have alterations in the microbiota of saliva, the stomach, and duodenum, which could contribute to symptoms of functional GI disorders.

Outsourcing trust to the information infrastructure in schools

Purpose

This paper investigates the experiences of school teachers of supporting pupils and their apprehensions of how pupils search and assess information when search engines have become a technology of literacy in schools. By situating technologies of literacy as sociomaterial the purpose of this paper is to analyse and discuss these experiences and understandings in order to challenge dominant views of search in information literacy research.

Design/methodology/approach

Six focus group interviews with in total 39 teachers working at four different elementary and secondary schools were conducted in the autumn of 2014. Analysis was done using a sociomaterial perspective, which provides tools for understanding how pupils and teachers interact with and are demanded to translate their interest to technologies of literacy, in this case search engines, such as Google.

Findings

The teachers expressed difficulties of conceptualizing search as something they could teach. When they did, search was most often identified as a practical skill. A critical perspective on search, recognizing the role of Google as a dominant part of the information infrastructure and a co-constructor of what there is to know was largely lacking. As a consequence of this neglected responsibility of teaching search, critical assessment of online information was conflated with Google’s relevance ranking.

Originality/value

The study develops a critical understanding of the role of searching and search engines as technologies of literacy in relation to critical assessment in schools. This is of value for information literacy training.

A Spontaneous Missense Mutation in Branched Chain Keto Acid Dehydrogenase Kinase in the Rat Affects Both the Central and Peripheral Nervous Systems

A novel mutation, causing a phenotype we named frogleg because its most obvious characteristic is a severe splaying of the hind limbs, arose spontaneously in a colony of Sprague-Dawley rats. Frogleg is a complex phenotype that includes abnormalities in hind limb function, reduced brain weight with dilated ventricles and infertility. Using micro-satellite markers spanning the entire rat genome, the mutation was mapped to a region of rat chromosome 1 between D1Rat131 and D1Rat287. Analysis of whole genome sequencing data within the linkage interval, identified a missense mutation in the branched-chain alpha-keto dehydrogenase kinase (Bckdk) gene. The protein encoded by Bckdk is an integral part of an enzyme complex located in the mitochondrial matrix of many tissues which regulates the levels of the branched-chain amino acids (BCAAs), leucine, isoleucine and valine. BCAAs are essential amino acids (not synthesized by the body), and circulating levels must be tightly regulated; levels that are too high or too low are both deleterious. BCKDK phosphorylates Ser293 of the E1α subunit of the BCKDH protein, which catalyzes the rate-limiting step in the catabolism of the BCAAs, inhibiting BCKDH and thereby, limiting breakdown of the BCAAs. In contrast, when Ser293 is not phosphorylated, BCKDH activity is unchecked and the levels of the BCAAs will decrease dramatically. The mutation is located within the kinase domain of Bckdk and is predicted to be damaging. Consistent with this, we show that in rats homozygous for the mutation, phosphorylation of BCKDH in the brain is markedly decreased relative to wild type or heterozygous littermates. Further, circulating levels of the BCAAs are reduced by 70-80% in animals homozygous for the mutation. The frogleg phenotype shares important characteristics with a previously described Bckdk knockout mouse and with human subjects with Bckdk mutations. In addition, we report novel data regarding peripheral neuropathy of the hind limbs.

To assess and be assessed

Purpose

– The purpose of this paper is to explore how students construct narratives of themselves as information seekers in a school context where their descriptions of their information activities are assessed and graded.

Design/methodology/approach

– Blog posts on credibility judgements written by 28 students at a Swedish upper secondary school were analysed through a bottom-up coding process based in the sociocultural concept of narratives of selves.

Findings

– Two tensions in the students’ accounts are identified. The first tension is that between the description of the individual, independent student and the description of the good group member. The second tension is between describing oneself as an independent information seeker and at the same time as someone who seeks information in ways that are sanctioned within the school setting.

Research limitations/implications

– The study focuses on a specific social practice and on situated activities, but also illustrates some aspects of information activities that pertain to educational contexts in general. It explores how social norms related to credibility judgements are expressed and negotiated in discursive interaction.

Practical implications

– The study highlights that when information activities become objects of assessment, careful consideration of what aspects are meant to be assessed is necessary.

Originality/value

– The study is based on the idea of information activities as socially and discursively shaped, and it illustrates some of the consequences when information activities become objects of teaching, learning, and grading.

Efficacy of topical dorzolamide therapy for cystoid macular edema in a patient with MFRP-related nanophthalmos-retinitis pigmentosa-foveoschisis-optic disk drusen syndrome

PURPOSE

Mutations in the MFRP (membrane-type frizzled-related protein) gene leads to an entity characterized by retinitis pigmentosa, nanophthalmos, optic disk drusen, and macular changes, originally described as foveoschisis. Despite the association of MFRP gene mutation and increase in macular thickness, no treatment modality has been described for cystoid macular edema related to this particular entity so far.

METHODS

In this case report, a 52-year-old woman presented with nanophthalmos, optic disk drusen, retinitis pigmentosa, and increase in macular thickness. Genetic analysis revealed an MFRP gene mutation. The patient was treated with topical carbonic anhydrase inhibitors.

RESULTS

A progressive decrease in macular thickness and cystic changes was observed during the 2-month course of topical carbonic anhydrase inhibitor treatment, and best-corrected visual acuity improved from 20/100 to 20/50. Macular thickness remained stable after 6 months of follow-up.

CONCLUSION

Cystoid macular edema is part of the macular changes noted in the MFRP mutation-related nanophthalmos-retinitis pigmentosa-foveoschisis-optic disk drusen, syndrome. Taking into account that resolution of cystoid macular edema in patients with retinitis pigmentosa may delay an irreversible decrease in visual acuity, treatment should be considered when cystic changes are suspected. Topical carbonic anhydrase inhibitor was effective in decreasing macular thickness and cystic changes in the patient reported.

Effects of a stress management program on vital exhaustion and depression in women with coronary heart disease: a randomized controlled intervention study

OBJECTIVES

Psychosocial factors, including depression and vital exhaustion (VE) are associated with adverse outcome in coronary heart disease (CHD). Women with CHD are poor responders to psychosocial treatment and knowledge regarding which treatment modality works in them is limited. This randomized controlled clinical study evaluated the effect of a 1-year stress management program, aimed at reducing symptoms of depression and VE in CHD women.

DESIGN

Patients were 247 women, < or =75 years, recruited consecutively after a cardiac event and randomly assigned to either stress management (20 2-h sessions) and medical care by a cardiologist, or to obtaining usual health care as controls. Measurements at; baseline (6-8 weeks after randomization), 10 weeks (after 10 intervention sessions), 1 year (end of intervention) and 1-2 years follow-up.

RESULTS

For VE, intention to treat analysis showed effects for time (P < 0.001) and time x treatment interaction (P = 0.005), reflecting that both groups improved over time, and that the decrease of VE was more pronounced in the intervention group. However, the level of VE was higher in the intervention group than amongst controls at baseline, 22.7 vs. 19.4 (P = 0.036) but it did not differ later. The change in depressive symptoms did not differ between the groups.

CONCLUSIONS

CHD women attending our program experienced a more pronounced decrease in VE than controls. However, as they had higher baseline levels, due to regression towards the mean we cannot attribute the decrease in VE to the intervention. Whether the program has long-term beneficial effects needs to be evaluated.

Constructing librarians' information literacy expertise in the domain of nursing

This article investigates negotiations of librarians' expertise in relation to information literacy at the micro-level, specifically in the domain of nursing education. A qualitaitve empirical framework is employed. The study draws on 18 semi-structured interviews, 16 with Swedish nursing students, one with a librarian and one with a nursing professor. Three themes on librarians' expertise emerge in the findings: technical-administrative, information searching and source evaluation expertise. The themes have different foci which are shown to be relatively independent, or dependent on the domain of nursing. The results indicate that it is important for librarians to navigate between two different strands of perceiving information literacy practices, either as generic or as embedded.

betaA3/A1-crystallin in astroglial cells regulates retinal vascular remodeling during development

Vascular remodeling is a complex process critical to development of the mature vascular system. Astrocytes are known to be indispensable for initial formation of the retinal vasculature; our studies with the Nuc1 rat provide novel evidence that these cells are also essential in the retinal vascular remodeling process. Nuc1 is a spontaneous mutation in the Sprague-Dawley rat originally characterized by nuclear cataracts in the heterozygote and microphthalmia in the homozygote. We report here that the Nuc1 allele results from mutation of the betaA3/A1-crystallin gene, which in the neural retina is expressed only in astrocytes. We demonstrate striking structural abnormalities in Nuc1 astrocytes with profound effects on the organization of intermediate filaments. While vessels form in the Nuc1 retina, the subsequent remodeling process required to provide a mature vascular network is deficient. Our data implicate betaA3/A1-crystallin as an important regulatory factor mediating vascular patterning and remodeling in the retina.

Burnout among women: associations with demographic/socio-economic, work, life-style and health factors

This study examined the occurrence of low/high burnout among women and the demographic/socio-economic, work, life-style, and health "correlates" of high burnout. The sample consisted of 6.000 randomly selected women from the general population, of which 3.591 participated. The design was cross-sectional. The univariate analyses showed that about 21% of the women had high burnout, and compared to those with low burnout, they were more often younger, divorced, blue-collar workers, lower educated, foreigners, on unemployment/retirement/sick-leave, financially strained, used more medication and cigarettes, reported higher work demands and lower control/social support at work, more somatic problems (e.g. pain) and depression. The regression analysis showed that only age, sick-leave, financial strain, medication, work demands, depression and somatic ailments were independently associated with high burnout. Thus, women with high burnout were apparently faring poorly financially, emotionally and physically. Considering our findings, interventions to alleviate their problems may be necessary. We may have provided new insights into women's burnout experiences, but longitudinal studies are warranted to firmly identify "determinants" of burnout.

Intensive group cognitive treatment and individual cognitive therapy vs. treatment as usual in social phobia: a randomized controlled trial

To compare the effects of an intensive group cognitive treatment (IGCT) to individual cognitive therapy (ICT) and treatment as usual (TAU) in social phobia (DSM-IV).

METHOD

Hundred patients were randomized to: IGCT involving 16 group sessions spread over three weeks; ICT involving 16 shorter weekly sessions in 4 months and; TAU involving an indicated selective serotonin reuptake inhibitor (SSRI) with therapy sessions as required for 1 year. The main outcome measure was a Social Phobia Composite that combined several standardized self-report measures. Diagnostic assessment was repeated at 1-year follow-up.

RESULTS

Significant improvements were observed with all treatments. ICT was superior to IGCT and TAU, which did not differ in overall effectiveness.

CONCLUSION

The study confirms and extends previously reported findings that ICT is more effective than group cognitive treatment and treatment with SSRIs. IGCT lasts only 3 weeks, and is as effective as more protracted TAU.

A G1103R mutation in CRB1 is co-inherited with high hyperopia and Leber congenital amaurosis

PURPOSE

To identify the genetic basis of recessive inheritance of high hyperopia and Leber congenital amaurosis (LCA) in a family of Middle Eastern origin.

MATERIALS AND METHODS

The patients were examined using standard ophthalmic techniques. DNA samples were obtained and genetic linkage was carried out using polymorphic markers flanking the known genes and loci for LCA. Exons were amplified and sequenced.

RESULTS

All four members of this family affected by LCA showed high to extreme hyperopia, with average spherical refractive errors ranging from +5.00 to +10.00. Linkage was obtained to 1q31.3 with a maximal LOD score of 5.20 and a mutation found in exon 9 of the CRB1 gene, causing a G1103R substitution at a highly conserved site in the protein. CRB1 is a vertebrate homolog of the Drosophila crumbs gene, which is required for photoreceptor morphogenesis, and has been associated with either retinitis pigmentosa (RP) or LCA. This sequence variant has previously been reported as a compound heterozygote in one sporadic LCA patient.

CONCLUSION

Although hyperopia has been associated with LCA, it is typically moderate and variable between patients with the same mutation. In addition, some CRB1 mutations can be associated with either RP or LCA. We have shown that hyperopia and LCA are linked to the mutant CRB1 gene itself and are not dependent on unlinked modifiers.

Posterior polar cataract: genetic analysis of a large family

Congenital cataracts are clinically and genetically heterogeneous. Loci for autosomal dominant posterior polar cataracts have been mapped to chromosomes 1p36, 11q22-q22.3, 16q22, and 20p12-q12. We investigated a large four-generation family with 20 individuals affected with congenital posterior polar cataracts. After exclusion of known loci for posterior polar cataracts, a genome-wide screen was conducted. In this family, we mapped dominant congenital posterior polar cataracts to chromosome 10q24. On haplotype analysis, we identified an 11-cM interval between loci D10S1680 and D10S467, which included the PITX3 gene. On sequencing the coding region of PITX3, we found a 17-base-pair duplication in exon 4. Although the same genotype was described in a family with ASMD and cataracts, the common phenotype of this mutation is probably posterior polar cataract; a modifier gene is presumed to cause anterior segment abnormalities in the previously described patients. The same mutation was recently identified in four families with congenital cataracts. This study provides further evidence of genetic heterogeneity of autosomal dominant posterior polar cataract.

A spontaneous mutation affects programmed cell death during development of the rat eye

We have discovered a spontaneous mutation in the Sprague-Dawley rat with a novel eye phenotype that we have named Nuc1. The Nuc1 mutation behaves as a single semi-dominant locus with an intermediate phenotype in the heterozygotes. Heterozygotes exhibit nuclear cataracts. Homozygous Nuc1 rats are fully viable and have microphthalmia, retinal abnormalities and disruption of lens structure shortly before birth. The homozygous mutant shows no obvious pathology outside of the eye, indicating that the mutation is highly eye specific in its effects. An unusual feature of the mutation is that it prevents the normal programmed loss of nuclei from lens fiber cells, but does not affect the loss of other organelles. TUNEL, light, and electron microscopic studies show normal intact nuclei in lens fibers, in contrast to many other models with degenerate nuclei and unlike normal lenses where no such nuclei remain. The beaded filament protein, filensin, is down-regulated in fibers of Nuc1, while heat shock cognate 70 is up-regulated. Homozygous retinas are thicker than normal, and TUNEL labeling indicates roughly half the number of apoptotic cells compared to a wild-type retina. The transient layer of Chievitz persists in adult Nuc1 retina, indicative of delayed development. Hence, Nuc1 is a novel mutation that could be an eye-specific regulator of apoptosis.

A missense mutation in GUCY2D acts as a genetic modifier in RPE65-related Leber Congenital Amaurosis

Leber congenital amaurosis (LCA) is a clinically and genetically heterogeneous severe retinal dystrophy presenting in infancy. To explain the phenotypical variability observed in two affected siblings of a consanguineous pedigree diagnosed with LCA and establish a genotype-phenotype correlation, we screened GUCY2D, RPE65, CRX, AIPL1, and RPGRIP1 for mutations. The more severely affected sibling carried a heterozygous missense mutation in the GUCY2D gene (Ile539Val), which did not segregate with the disease phenotype. Subsequently, a homozygous nonsense mutation (Glu102STOP) in the RPE65 gene was identified in both affected siblings, thus identifying the causative gene. This data provides evidence for the presence of genetic modulation in LCA. It appears that the heterozygous GUCY2D mutation further disrupts the already compromised photoreceptor function resulting in more severe retinal dysfunction in the older sibling. We suggest that the unusual phenotypic variability in these two siblings with LCA is caused by the modifying effect of a heterozygous GUCY2D mutation observed against the disease background of a homozygous RPE65 mutation.

Two-year results of a controlled study of residential rehabilitation for patients treated with percutaneous transluminal coronary angioplasty. A randomized study of a multifactorial programme

AIMS

In a multifactorial lifestyle behaviour programme, of 2 years duration, to study the maintenance of achieved behaviour and risk factor-related changes.

METHODS AND RESULTS

Out of a consecutive population of 151 patients treated with percutaneous transluminal angioplasty under 65 years of age, 87 were randomly allocated to an intervention group (n=46) or to a control group (n=41). The programme started with a 4 week residential stay, which was focused on health education and the achievement of behaviour change. During the first year of follow-up, a maintenance programme included regular contacts with a nurse, while no further rehabilitative efforts were offered during the second year. One patient died (control). During the second year the proportion of hospitalized patients was lower in the intervention group (4% vs 20%;P<0.05). Patients in the intervention group improved several lifestyle dependent behaviours: diet (index at 0, 12 and 24 months): 10.5+/-3. 4, 12.9+/-2.5 and 12.4+/-2.6 in the intervention group (I) vs 10. 1+/-3.2, 10.7+/-3.0 and 11.8+/-3.2 in the control group (C);P<0.05, exercise sessions per week: 2.5+/-2.3, 4.5+/-1.9 and 4.4+/-2.1 (I) vs 3.1+/-2.2, 3.5+/-2.3 and 3.7+/-2.7 (C);P<0.05, and smoking; 18%, 6% and 9% (I) vs 12%, 21% and 18% (C);P<0.05. This corresponded to improvement in exercise capacity (0, 12 and 24 months): 156+/-42, 174+/-49 and 165+/-47 W (I) vs 164+/-40, 163+/-49 and 156+/-48 watts (C);P<0.05. There were no significant differences between the two groups with regard to serum cholesterol levels at 0 and 24 months: 5. 4+/-0.8 and 5.2+/-0.9 mmol. l(-1)(I) vs 5.4+/-1.0 and 4.9+/-0.9 mmol. l(-1)(C); ns, low density lipoprotein cholesterol level: 3.6+/-0.8 and 3.4+/-0.8 mmol. l(-1)(I) vs 3.7+/-0.9 and 3.3+/-0.7 mmol. l(-1)(C); ns, triglyceride level: 2.2+/-1.6 and 1.8+/-1.3 mmol. l(-1)(I) vs 2.2+/-1.4 and 1.6+/-0.6 mmol. l(-1)(C); ns, body mass index (0, 12 and 24 months): 27.5+/-4.5, 27.0+/-4.3 and 27.4+/- 4.5 kg. m(-2)(I) vs 26.8+/-2.8, 26.9+/-2.7 and 26.9+/- 3.2 kg. m(-2)(C); ns, waist/hip ratio or blood pressure. The two groups did not differ in quality of life, or psychological factors. Return to work after 12 and 24 months was 74% and 78% (I) vs 68% and 61% (C); ns.

CONCLUSION

This rehabilitation programme influenced important lifestyle behaviour and reduced some, but not all, important risk factors

Multifactorial evaluation of a program for lifestyle behavior change in rehabilitation and secondary prevention of coronary artery disease

A comprehensive, multifactorial lifestyle behavior change program was developed for rehabilitation and secondary prevention of subjects with coronary artery disease. The purpose of the present report is to describe this intervention model and to analyze results achieved in a first group of consecutive participants. Main inclusion criteria for the 292 subjects were a recent history of acute myocardial infarction, coronary artery bypass surgery, or percutaneous transluminal coronary angioplasty. The program commenced with a 4-week residential stay, with the focus on health education and the achievement of behavior change in major lifestyle areas. During the year of follow-up a systematic maintenance program included regular contact with a nurse. Morbidity and mortality was low. Self-reported quality of life improved and there were significant improvements in blood lipids, exercise capacity and body mass index. There were also significant changes both in psychological variables such as Type A behavior, anger, hostility, and in major lifestyle areas such as stress reactions, diet, exercise and smoking. These changes compared favorably with data from relevant samples from the Swedish normal population. This program had a considerable effect on a number of important factors for rehabilitation and secondary prevention of coronary artery disease.

Behavioral effects of a comprehensive, multifactorial program for lifestyle change after percutaneous transluminal coronary angioplasty: a prospective, randomized controlled study

A group of 93 coronary patients recently treated with percutaneous transluminal coronary angioplasty (PTCA) were randomly assigned to either an intervention or a control group. Subjects in the intervention group participated in a comprehensive behaviorally oriented program aimed at achieving significant long-term changes in risk factor-related lifestyle behavior. Assessments of lifestyle behaviors, psychological factors, biological risk factors, and rehabilitation as well as secondary prevention endpoints were carried out, at inclusion and after 12 months. Results showed that the intervention patients, as compared with controls, improved significantly on measures assessing smoking, exercise, and diet habits. These self-rated changes were confirmed by weight reductions and improved exercise capacity, as well as by between-group differences in subclinical chest pain during an exercise test. However, few effects were found on the different psychological variables, as well as on morbidity or return to work.

Pax-6, Prox 1, and Chx10 homeobox gene expression correlates with phenotypic fate of retinal precursor cells

PURPOSE

To study the expression patterns of the homeobox genes Pax-6, Prox 1, and Chx10 during chick retinal development in vivo and in vitro.

METHODS

Sections of paraformaldehyde-fixed, paraffin-embedded eyes were obtained at a range of developmental stages. In situ hybridization was carried out on tissue sections using digoxigenin-labeled sense and antisense RNA probes that recognize chicken Pax-6 and Prox 1 (whose sequences were already available), and chicken Chx10 (which was cloned and sequenced as part of this study). Selected developmental stages were also studied by immunocytochemistry with antibodies against Pax-6 and Prox 1, and by Northern blot analysis using 32P-labeled probes.

RESULTS

Until embryonic day (ED) 5, in situ hybridization shows widespread, diffuse distribution of all three genes. Between ED 6 and ED 8, however, they acquire distinct, topographically specific patterns of expression. The Prox 1 signal is predominantly expressed in the prospective horizontal cell layer of the neuroepithelium, decreases vitreally, and is absent from ganglion cells and the prospective photoreceptor layer. Pax-6 is strongly expressed only in the prospective ganglion-cell and amacrine-cell regions at the same stages, and is not detected in prospective photoreceptors. Chx10 expression becomes concentrated in the future bipolar-cell region of the inner nuclear layer. Similar patterns are maintained by ED 15 through ED 18, after cell differentiation has taken place. Pax-6 and Prox 1 immunoreactive materials showed nuclear localization and a pattern of laminar distribution equivalent to that seen by in situ hybridization.

CONCLUSIONS

These results suggest that the differentiated fate of retinal precursor cells may be influenced by Pax-6, Prox 1, or Chx10, this hypothesis is now being tested using dissociated chick embryo retinal cell cultures.

Chicken homeobox gene Prox 1 related to Drosophila prospero is expressed in the developing lens and retina

Prox 1 is the vertebrate homolog of Drosophila prospero, a gene known to be expressed in the lens-secreting cone cells of fly ommatidia. Chicken Prox 1 cDNAs were isolated from 14 day embryonic chicken lenses, and a complete open reading frame encoding an 83 kDa protein was elucidated. The homeodomains of chicken and mouse Prox 1 are identical at the amino acid level and are 65-67% similar to the homeodomains of Drosophila and C. elegans prospero. The homology between these proteins extends beyond the homeodomain. There is 56% identity between chicken Prox 1 and Drosophila prospero in the C-terminal region downstream of the homeodomain, whereas there is little similarity upstream of the homeodomain. Prox 1 is expressed most actively in the developing lens and midgut and at lower levels in the developing brain, heart, muscle, and retina. cDNA sequencing has established that there are alternatively spliced forms of the single Prox 1 gene, which probably account for the two abundant RNAs of about 2 and 8 kb and two less abundant RNAs close to 3.5 kb in length in the lens. In the lens fibers, only the shortest mRNA was present, whereas, in the epithelial cells, both short and long mRNAs were detected. By using in situ hybridization, expression of the Prox 1 gene was first detected at stage 14 in the early lens placode and slightly preceded the expression of delta 1-crystallin, the first crystallin gene expressed in the developing chicken lens. At later stages of development, Prox 1 mRNA was observed throughout the lens, but it appeared more abundant around the bow region of the equator than in the anterior epithelium or the fibers. In the retina, expression of the Prox 1 gene was detected mainly in the inner nuclear layer during later stages of histogenesis. The conserved pattern of Prox 1/prospero gene expression in vertebrates and Drosophila suggests that Prox 1, like Pax-6, may be essential for eye development in different systematic groups.

Cardiovascular reactivity, Type A behavior, and coronary heart disease: comparisons between myocardial infarction patients and controls during laboratory-induced stress

Cardiovascular responses to a series of laboratory stressors were examined in middle-aged Type A and Type B men. The subjects were 30 patients with diagnosed myocardial infarction (NYHA Class 1) and 26 age-matched healthy controls. All subjects were nonsmokers in the normotensive range, and none were on medication. Blood pressure, heart rate, forearm blood flow and resistance, and impedance cardiography-determined response variables were obtained during performance and recovery periods of both mental and physical tasks. The patients showed elevated reactivity in systolic blood pressure and cardiac output and prolonged systolic time ratio during mental stress tasks and elevated total peripheral resistance and lower cardiac output and stroke volume during physical tasks, as compared with control subjects. Thus, the difference in blood pressure reactivity between patients and controls appeared to be primarily dependent on the vascular component during physical tasks, whereas the mental tasks promoted a hemodynamic response pattern more consistent with beta adrenergic activation. Type A men, irrespective of coronary status, showed larger systolic and diastolic blood pressure response to both mental and physical stress than did Type B men.

Pax-6 is first expressed in a region of ectoderm anterior to the early neural plate: implications for stepwise determination of the lens

The Pax-6 gene encodes a DNA-binding transcription factor essential to normal development of the mammalian eye. We have found that in the chick embryo, the Pax-6 gene is first expressed in a crescent-shaped region of future head ectoderm that adjoins the anterior margin of the early neural plate. As development proceeds, this region of Pax-6-positive ectoderm becomes divided into two bilateral domains. Upon contact with the optic vesicles, portions of these domains give rise to the invaginating lens placodes, which contain high levels of Pax-6 mRNA. As with mouse, rat, and zebrafish, chick Pax-6 is also expressed in the neural epithelium of the forebrain and optic vesicles. However, our results indicate that the onset of expression in the prospective head ectoderm occurs at a substantially earlier stage. Experiments involving unilateral ablation of the anterior neural plate indicate that contact with an optic vesicle is not required to maintain expression of Pax-6 in the ectoderm. Experiments in which optic vesicles have been displaced from their normal location further suggest that positioning of Pax-6 domains in the head ectoderm is independent of neighboring optic vesicles. Homozygous defects in the mouse and rat Pax-6 gene are known to cause complete failure of lens formation at the optic vesicle stage and block subsequent development of the optic cup. Our results raise the possibility that Pax-6 may be involved in the early establishment of lens-competent regions within the head ectoderm.

Psychophysiological effects of cardiac rehabilitation in post-myocardial infarction patients

Psychophysiological reactivity and cardiovascular functioning were assessed in 40 patients with coronary heart disease before and after taking part in either a Type A modification training program or a control condition. Treated patients showed an overall attenuated heart rate (HR) response and prolonged diastolic time to mental stress performance, during recovery and rest periods, as compared lo control patients. No other measure, including impedance-cardiography-derived measures, differentiated the two groups. The treatment group showed reduction from before lo after treatment in 24-hr minimum IIR level and decreased frequencies of premature ventricular contractions, whereas the control group showed an opposite trend. Results from an exercise test suggested the same direction for resting IIR and double-product levels. The two groups did not differ in maximal systolic and diastolic blood pressure or in maximal double-product levels, despite a differential development, in favor of the treatment group, in maximal work capacity.

An early marker of axial pattern in the chick embryo and its respecification by retinoic acid

Chick Ghox 2.9 protein, a homeodomain-containing polypeptide, is first detected in the mid-gastrula stage embryo and its levels increase rapidly in the late gastrula. At this time, the initially narrow band of expression along the primitive streak expands laterally to form a shield-like domain that encompasses almost the entire posterior region of the embryo and extends anteriorly as far as Hensen's node. We have found that this expression domain co-localizes with a morphological feature that consists of a stratum of refractile, thickened mesoderm. Antibody-staining indicates that Ghox 2.9 protein is present in all cells of this mesodermal region. In contrast, expression within the ectoderm overlying the region of refractile mesoderm varies considerably. The highest levels of expression are found in ectoderm near the streak and surrounding Hensen's node, regions that recent fate mapping studies suggest that primarily destined to give rise to neurectoderm. At the definitive streak stage (Hamburger and Hamilton stage 4) the chick embryo is especially sensitive to the induction of axial malformations by retinoic acid. Four hours after the treatment of definitive streak embryos with a pulse of retinoic acid the expression of Ghox 2.9 protein is greatly elevated. This ectopic expression occurs in tissues anterior to Hensen's node, including floor plate, notochord, presumptive neural plate and lateral plate mesoderm, but does not occur in the anteriormost region of the embryo. The ectopic induction of Ghox 2.9 is strongest in ectoderm, and weaker in the underlying mesoderm. Endoderm throughout the embryo is unresponsive. At stage 11, Ghox 2.9 is normally expressed at high levels within rhombomere 4 of the developing hindbrain. In retinoic-acid-treated embryos which have developed to this stage, typical rhombomere boundaries are largely absent. Nevertheless, Ghox 2.9 is still expressed as a discrete band, but one that is widened and displaced to a more anterior position.

Classical conditioning of vascular responses in mild hypertensives and normotensives

Using a discriminative classical conditioning paradigm, this study addresses the question of whether vascular responses are more easily acquired or slower to extinguish in mild hypertensives than in normotensive controls. We subjected 18 mild hypertensives, with a resting systolic/diastolic blood pressure of 141/100 mmHg, and 17 normotensive controls similar in age, with resting systolic/diastolic blood pressure 122/80 mmHg, to a discriminative Pavlovian conditioning paradigm with tones of 8 s duration serving as conditioned stimuli (CS) and a mild electric shock as an unconditioned stimulus (UCS). Digital finger pulse volume (FPV) responses were recorded during an acquisition phase, where CS+, but not CS-, was repeatedly paired with the UCS (12 trials), and an extinction phase where shocks were withheld (12 trials). During the acquisition phase, mild hypertensives displayed greater anticipatory vasoconstrictive responses both to CS+ and CS- compared with normotensive controls. In addition, unconditioned FPV responses were enhanced in mild hypertensives. During the extinction phase, mild hypertensives evidenced increased resistance to extinction since conditioned vasoconstriction was more frequently observed in response to CS+ than to CS- in mild hypertensives only. Thus, vascular dysregulation in mild hypertensives was evident both for unconditioned and conditioned vasoconstriction. Data are compatible both with a centrally determined increased conditionability in mild hypertensive compared with normotensive and with a decreased threshold for peripheral vascular responsiveness among mild hypertensives.

Molecular approaches to vertebrate limb morphogenesis

It has long been proposed that concentration gradients of morphogens provide cues to specify cell fate in embryonic fields. Recent work in a variety of vertebrate systems give bona fide evidence that retinoic acid, the biologically active form of vitamin A, is a candidate for such a morphogen. In the developing chick wing, for example, locally applied retinoic acid triggers striking changes in the pattern along the anteroposterior axis. Instead of giving rise to a wing with the normal 234 digit pattern, wing buds treated with retinoic acid develop a 432234 mirror-image symmetrical digit pattern.

For this review, we focus on three aspects of limb morphogenesis. (1) We summarize the experimental evidence supporting the notion that retinoic acid is a candidate morphogen. (2) Limb buds contain high levels of cellular retinoic-acid-binding protein (CRABP). Using order of magnitude calculations, we evaluate how the concentration of CRABP might affect the occupancy state of the retinoic acid receptor. (3) We discuss the spatio-temporal expression pattern of homeobox-containing genes in the developing limb and speculate about the possibility that retinoic acid influences the pattern of expression of homeobox genes.

Cortisol excretion during the defense reaction in humans

Twelve subjects with specific phobias were exposed to slides with a phobic or a neutral content while cortisol excretion, electrodermal activity, and distress-ratings were studied. Six subjects fearful of blood and mutilation, and six of snakes or spiders, were presented with two sets of ten different slides (phobic or neutral; 8-sec exposures, separated by 50-sec intervals) with the order of presentation balanced between days. Before and after each session, subjects rated feelings of distress, and urine samples were obtained for the determination of cortisol by radioimmunoassay. Electrodermal activity was recorded before and during slide presentation. Compared to neutral exposures, phobic slides elicited larger cortisol excretion, higher distress ratings, and greater skin-conductance responses with slower recovery. No differences between animal and blood and mutilation phobics were observed. Thus, humans having specific phobias exhibit pituitary-adrenal cortical arousal during the defense reaction elicited by slides of their phobic objects.

New way to isolate simian virus 40 nucleoprotein complexes from infected cells: use of a thiol-specific reagent

A new method for the isolation of simian virus 40 nucleoprotein complexes from nuclei of lytically infected cells is described. The method is based on the addition of a thiol-specific reagent, 5'5'-dithiobis(2-nitrobenzoic acid), to lysis and extraction buffers. By inhibiting an uncoating activity during simian virus 40 extraction, 5'5'-dithiobis (2-nitrobenzoic acid) allows the use of efficient extraction buffers, such as one containing Triton X-100 and EDTA, for the isolation of native simian virus 40 minichromosomes and virion-type structures. Use of the method is illustrated by following encapsidation of simian virus 40 minichromosomes in a pulse-chase experiment. Since 5'5'-dithiobis (2-nitrobenzoic acid) is an inhibitor of many different enzymes, the 5',5'-dithiobis (2-nitrobenzoic acid) extraction technique may be useful for the isolation of not only papovaviruses but also other viruses and possibly cellular chromatin.

Arrest of segregation leads to accumulation of highly intertwined catenated dimers: dissection of the final stages of SV40 DNA replication

When SV40-infected cells are placed into hypertonic medium, newly synthesized DNA accumulates as form C catenated dimers. These molecules consist of two supercoiled monomer circles of SV40 DNA interlocked by one or more topological inter-twinings and are seen as transiently labeled inter-mediates during normal replication. Form C catenated dimers represent pure segregation intermediates, replicative DNA structures in which DNA synthesis is complete but which still require topological separation of the two daughter circles. Hypertonic shock seems to block selectively a type II topoisomerase activity involved in disentangling the two circles. This is reflected in the fact that form C catenated dimers that accumulate during the block are highly intertwined with catenation linkage numbers up to C(L) = 20. While initiation of replication is also inhibited by hypertonic treatment, ongoing SV40 DNA synthesis is not affected, and replication is free to proceed from the earliest cairns structure through to form C catenated dimers. The block to segregation is rapidly and completely released by shifting the cells back to normal medium. A much slower recovery of DNA segregation takes place on prolonged incubation in hypertonic medium, perhaps because of some cellular homeostatic mechanism. The results of this work lead to a detailed view of the final stages of SV40 DNA replication.

Terminal stages of SV40 DNA replication proceed via multiply intertwined catenated dimers

We have identified a new class of SV40 replicative intermediates which consists of a least 20 discrete DNA species. All members of this class are catenated dimers, two circular molecules of SV40 duplex DNA linked topologically by one or more intertwining events. Most of these molecules are linked by several intertwining events, and the range of linkage states observed runs from L = 1 to L = 10. A catenated dimer with a given linkage state is assigned to one of three distinct families (A, B or C) depending on the open or covalently closed nature of its two circular components: in form A catenated dimers, both circles are nicked or gapped; in form B, one of the circles is supercoiled; and in form C, both circles are supercoiled. Members of all three of these families are found in SV40 chromatin pulse-labeled with 3H-thymidine, and together they comprise 10-20% of the total replicative form SV40 DNA, appearing as a discrete series of electrophoretically resolved bands superimposed upon a continuous smear of growing cairns structures. The distribution of linkage states varies between the families, A being the most intertwined and C the least intertwined. Upon a chase with cold thymidine, label is lost rapidly from all these catenated DNA species. We suggest that the sequence A leads to B leads to C leads to mature monomeric supercoiled SV40 DNA represents the final stages of SV40 replication, and that a special enzyme activity exists in vivo to uncatenate the SV40 daughter chromosomes.

A stretch of "late" SV40 viral DNA about 400 bp long which includes the origin of replication is specifically exposed in SV40 minichromosomes

Examination of DNA fragments produced from either formaldehyde-fixed or unfixed SV40 minichromosomes by multiple-cut restriction endonucleases has led to the following major results: Exhaustive digestion of unfixed minichromosomes with Hae III generated all ten major limit-digest DNA fragments as well as partial cleavage products. In striking contrast to this result, Hae III acted on formaldehyde-fixed minichromosomes to yield only one of the limit-digest fragments, F, which is located in the immediate vicinity of the origin of replication, spanning nucleotides 5169 and 250 on the DNA sequence map of Reddy et al. (1978). This 300 base pair (bp) fragment was released as naked DNA from formaldehyde-fixed, Hae III-digested minichromosomes following treatment either by pronase-SDS or by SDS alone. In the latter case, the remainder of the minichromosome retained its compact configuration as assayed by both sedimentational and electrophoretic methods. In minichromosomes, the F fragment is therefore not only accessible to Hae III at its ends, but is also neither formaldehyde cross-linked into any SDS-resistant nucleoprotein structure nor topologically "locked" within the compact minichromosomal particle. This same fragment was preferentially produced during the early stages of digestion of unfixed minichromosomes with Hae III, and its final yield in the exhaustive Hae III digest was significantly higher than that of other limit-digest fragments. Similar results were obtained upon digestion of either unfixed or formaldehyde-fixed minichromosomes with Alu I. In particular, of approximately twenty major limit-digest DNA fragments, only two fragments (F and P, encompassing nucleotides 5146 to 190, and 190 to 325, respectively) were produced by Alu I from the formaldehyde-fixed minichromosomes. All other restriction endonucleases tested (Mbo I, Mbo II, Hind III, Hin II+III and Hinf I), for which there are no closely spaced recognition sequences in the above mentioned regions of the SV40 genome, did not produce any significant amount of limit-digest DNA fragments from formaldehyde-fixed minichromosomes. These findings, taken together with our earlier data on the preferential exposure of the origin of replication in SV40 minichromosomes (Varshavsky, Sundin and Bohn, 1978), strongly suggest that a specific region of the "late" SV40 DNA approximately 400 bp long is uniquely exposed in the compact minichromosome. It is of interest that, in addition to the origin of replication, this region contains binding sites for T antigen (Tjian, 1977), specific tandem repeated sequences and apparently also the promoters for synthesis of late SV40 mRNAs (Fiers et al., 1978; Reddy et al., 1978).

C(2)H(4) metabolism in morning glory flowers

Flowers of Ipomoea tricolor Cav. (cv. Heavenly Blue) were cut at various stages of development and evaluated for their ability to metabolize ethylene. Freshly cut buds or flowers were treated in glass containers for 8 hours with 6 mul/liter of highly purified (14)C(2)H(4). Following removal of dissolved (14)C(2)H(4), radioactivity was determined for the different flower tissues and trappd CO(2). (14)C(2)H(4) oxidation to (14)CO(2) and tissue incorporation occurred at very low to nondetectable levels 2 to 3 days prior to flower opening. About 1 day prior to full bloom, just at the time when mature buds become responsive to ethylene (Kende and Hanson, Plant Physiol 1976, 57: 523-527), there was a dramatic increase in the capacity of the buds to oxidize (14)C(2)H(4) to (14)CO(2). This activity continued to increase until the flower was fully opened reaching a peak activity of 2,500 dpm per three flowers per 8 hours. It then declined as the flower closed and rapidly senesced. A similar but smaller peak occurred in tissue incorporation and it was followed by a second peak during late flower senescence. This first peak in tissue incorporation and the dramatic peak in ethylene oxidation slightly preceded a large peak of natural ethylene production which accompanied flower senescence. The ethylene metabolism observed was clearly dependent on cellular metabolism and did not involve microorganisms since heat killing destroyed this activity and badly contaminated heat-killed flowers were unable to metabolize ethylene.