CRE DNA binding proteins bind to the AP-1 target sequence and suppress AP-1 transcriptional activity in mouse keratinocytes

Previously, we have shown that nuclear extracts from cultured mouse keratinocytes induced to differentiate by increasing the levels of extra-cellular calcium contain Fra-1, Fra-2, Jun B, Jun D and c-Jun proteins that bind to the AP-1 DNA binding sequence. Despite this DNA binding activity, AP-1 reporter activity was suppressed in these cells. Here, we have detected the CREB family proteins CREB and CREMalpha as additional participants in the AP-1 DNA binding complex in differentiating keratinocytes. AP-1 and CRE DNA binding activity correlated with the induction of CREB, CREMalpha and ATF-1 and CREB phosphorylation at ser133 (ser133 phospho-CREB) in the transition from basal to differentiating keratinocytes, but the activity of a CRE reporter remained unchanged. In contrast, the CRE reporter was activated in the presence of the dominant-negative (DN) CREB mutants, KCREB and A-CREB, proteins that dimerize with CREB family members and block their ability to bind to DNA. The increase in CRE reporter activity in the presence of these mutants suggests that CRE-mediated transcriptional activity is suppressed in keratinocytes through protein-protein interactions involving a factor that dimerizes with the CREB leucine zipper. In experiments where the A-CREB mutant was co-transfected with an AP-1 reporter construct, transcriptional activity was also increased indicating that a CREB family member binds AP-1 sites and represses AP-1 transcriptional activity as well. Exogenous expression of the transcriptional repressor CREMalpha down-regulated both CRE and AP-1 reporters in keratinocytes suggesting that this factor may contribute to the suppression of AP-1 transcriptional activity observed in differentiating keratinocytes.

HIV quantitation in spiked vaginocervical secretions: lack of non-specific inhibitory factors. DATRI 005 Study Team. Division of AIDS Treatment Research Initiative

The objective of this study was to assess the effect of menstrual phase on the ability to quantitate HIV-1 in vaginocervical secretions (VCS) through reconstruction experiments with HIV seronegative VCS collected throughout the menstrual cycle. Measurement of HIV-1 inoculated into both fresh and frozen VCS was undertaken by quantitative micro co-culture, p24 antigen assay and polymerase chain reaction (PCR) for both HIV-1 RNA and pro-viral DNA. Two laboratories carried out these assays over a range of viral concentrations. The study involved a randomized factorial design and the factors were: (1) diluents (phases of the menstrual cycle and controls); (2) laboratories; (3) stock concentrations; and (4) frozen versus fresh VCS samples. Each assay was assessed independently using a random effects analysis of variance (ANOVA) model. No statistical differences due to menstrual cycle were seen in the assay results of p24 antigen (P = 0.08), PBMC culture (P = 0.74), plasma culture (P = 0.13), cell-free RNA (P = 0.44), cell-associated RNA (P = 0.58) and cell-associated DNA (P = 0.43). Inter-laboratory differences were statistically significant for cell-free RNA (P < 0.001), cell-associated DNA (P < 0.001) and p24 (P < 0.001). It is concluded that VCS obtained throughout the menstrual cycle from HIV-uninfected women lacks intrinsic inhibitory factors which could limit detection and quantification by antigen, culture or nucleic acid-based technologies for HIV-1 in VCS throughout the menstrual cycle. Using a standardized collection procedure, we suggest that variation in HIV quantity over time, when reported in VCS of infected women, should be attributed to HIV-associated biologic factors, rather than non-specific or other technical factors.

Diarrhoea morbidity in children in the Asaro Valley, Eastern Highlands Province, Papua New Guinea

A morbidity study of diarrhoea covering 1926 children aged less than 5 years was carried out in Goroka town and the Lowa and Asaro Census Divisions, Eastern Highlands Province between 1986 and 1989. The study involved weekly demographic surveillance of the total population and morbidity surveillance of children by lay reporters who enquired about the presence or absence on any of the preceding 8 days of a range of symptoms associated with diarrhoeal and respiratory diseases. A three-day symptom-free period was used to define distinct episodes of diarrhoea. The average number of episodes/child-year for all children in the study population was 3.0. Boys suffered a significantly higher incidence of diarrhoea under 48 months of age than girls (4.4 episodes compared to 3.6/child-year). Incidence was highest among those aged 6-17 months (5.5/child-year) with a rapid decline after age 35 months. Incidence of diarrhoea was highest in the more remote Asaro Census Division and was higher in periurban areas than in Goroka town. Incidence also varied significantly between villages, some villages experiencing up to 10 times the incidence of diarrhoea found in Goroka town. The incidence of diarrhoea was significantly higher in January than at other times of year. Duration of diarrhoea varied with age, the longest duration being an average of 4.7 days in the 12-17 months age group. In order to reduce diarrhoea morbidity, it is necessary to improve access to water, encourage improved hygiene practices and breastfeeding and warn people about the risks of sleeping with pigs.

Targeted disruption of the epidermal growth factor receptor impairs growth of squamous papillomas expressing the v-ras(Ha) oncogene but does not block in vitro keratinocyte responses to oncogenic ras

We have assessed the role of epidermal growth factor receptor (EGFR) signaling in biological responses to the v-ras(Ha) oncogene using primary keratinocytes from Egfr -/- mice and wild-type littermates. On the basis of several criteria, Egfr -/- keratinocytes were unresponsive to either acute or chronic exposure to several EGFR ligands but were stimulated to proliferate in response to several other mitogens. Although conditioned medium from primary keratinocytes transduced with v-ras(Ha) retrovirus (v-ras(Ha) keratinocytes) was a potent mitogen for wild-type but not Egfr -/- keratinocytes, v-ras(Ha) transduction of primary keratinocytes of either genotype resulted in a strong mitogenic response, arguing against an obligatory role for EGFR activation in v-ras(Ha)-mediated stimulation of keratinocyte proliferation. Infection with high-titer v-ras(Ha) retrovirus altered the keratin expression pattern in keratinocytes of both genotypes, suppressing differentiation-specific keratins K1 and K10 while activating aberrant expression of K8 and K18. In wild-type but not Egfr -/- cultures, K1 and K10 were also suppressed following infection at lower retroviral titers, presumably as a result of paracrine EGFR activation on uninfected cells present in these cultures. Squamous papillomas produced by grafting Egfr -/- v-ras(Ha) keratinocytes onto nude mice were only 21% of the size of wild-type v-ras(Ha) tumors, and a striking redistribution of S-phase cells was detected by immunostaining for bromodeoxyuridine. In Egfr -/- v-ras(Ha) papillomas, the fraction of total labeled nuclei detected in suprabasal layers was increased from 19 to 39%. In contrast, the basal layer labeling index of Egfr -/- papillomas was reduced to 34%, compared to 43% in wild-type tumors. Our results indicate that, although autocrine EGFR signaling is not required for keratinocyte responses to oncogenic ras in culture or benign tumor formation in nude mouse grafts, disruption of this pathway impairs growth of v-ras(Ha) papillomas by a mechanism that may involve alterations in keratinocyte cell cycle progression and/or migration in vivo.

Transmission intensity and its relationship to infection and disease due to Wuchereria bancrofti in Papua New Guinea

This study describes the relationship between transmission intensity and infection and disease due to Wuchereria bancrofti in an endemic area of Papua New Guinea. The prevalence of microfilaremia in the entire study population was 66%. Of 1892 persons examined, 6.2% and 12.3% had lymphedema of the legs and hydroceles, respectively. The prevalences of microfilaremia and clinical morbidity were lowest in persons <20 years old and increased progressively with age. Annual transmission potential and annual infective biting were monitored in five villages where Anopheles punctulatus and Anopheles koliensis are the only vectors of W. bancrofti. Both measures of the entomologic inoculation rate were positively associated with the village-specific microfilarial rate, mean intensity of microfilaremia, and prevalence of leg edema. These data indicate that transmission intensity is a major determinant of patent infection and morbidity rates in bancroftian filariasis.

Genetically null mice reveal a central role for epidermal growth factor receptor in the differentiation of the hair follicle and normal hair development

Mice harboring a targeted disruption of the epidermal growth factor receptor (EGFR) allele exhibit a severely disorganized hair follicle phenotype, fuzzy coat, and systemic disease resulting in death before 3 weeks. This skin phenotype was reproduced in whole skin grafts and in grafts of EGFR null hair follicle buds onto nude mice, providing a model to evaluate the natural evolution of skin lacking the EGFR. Hair follicles in grafts of null skin did not progress from anagen to telogen and scanning electron micrografts revealed wavy, flattened hair fibers with cuticular abnormalities. Many of the EGFR null hair follicles in the grafted skin were consumed by an inflammatory reaction resulting in complete hair loss in 67% of the grafts by 10 weeks. Localization of follicular differentiation markers including keratin 6, transglutaminase, and the hair keratins mHa2 and hacl-1 revealed a pattern of premature differentiation within the null hair follicles. In intact EGFR null mice, proliferation in the interfollicular epidermis, but not hair follicles, was greatly decreased in the absence of EGFR. In contrast, grafting of EGFR null skin resulted in a hyperplastic response in the epidermis that did not resolve even after 10 weeks, although the wound-induced hyperplasia in EGFR wild-type grafts had resolved within 3 to 4 weeks. Thus, epithelial expression of the EGFR has complex functions in the skin. It is important in delaying follicular differentiation, may serve to protect the hair follicle from immunological reactions, and modifies both normal and wound-induced epidermal proliferation but seems dispensable for follicular proliferation.

Central nitric oxide donors attenuate cardiovascular and central norepinephrine responses to stress

An earlier study showed that norepinephrine (NE) was released in the paraventricular nucleus (PVN) and posterior hypothalamus (PH) along with increases of mean arterial pressure (MAP) and heart rate (HR) during shaker stress (SS). Here we investigated the possibility that nitric oxide (NO) donors, infused into hypothalamus, could modulate responses to SS. In conscious rats, an injector-microdialysis probe, for direct application of donor and collection of extracellular NE, respectively, was inserted into PVN or PH; MAP and HR were recorded continuously from conscious rats. The NO donor, molsidomine (Mol), infused 5 or 30 min before SS, did not alter baseline values of NE, MAP, or HR, but did attenuate changes elicited by 5 min of SS; methylene blue blocked the effects of Mol. The NO donor, sodium nitroprusside, was much less effective than Mol as a modulator of stress-related effects. The results indicate that MAP, HR, and hypothalamic NE responses to environmental stress, but not baseline values, can be modulated by NO donors in the hypothalamus.

Single and repeated environmental stress: effect on plasma oxytocin, corticosterone, catecholamines, and behavior

Rat studies were done to further characterize an environmental model of stress designated shaker stress (SS). Plasma oxytocin (OT), corticosterone (CS), norepinephrine (NE), and epinephrine (E) were measured before and after 5 or 30 min of SS applied one time or applied 10 times over a 2-week period. The major findings were partial adaptation of plasma E within 30 min of acute SS, adaptation of plasma CS baselines but not responses to chronic SS, and complete adaptation of plasma OT responses to chronic SS. Poststress behavior during chronic SS was affected in the following ways: freezing time habituated, defecation and rearings increased, and grooming and teeth chattering remained relatively constant. The results show that SS produces consistent patterns of hormonal and behavioral responses; some aspects of the patterns are similar to those elicited by other environmental stresses, whereas some aspects are unique to SS. We conclude that rats do not adapt to repeated SS but rather that most hormonal and behavioral defense mechanisms are renewable on a daily basis.

Spatial and temporal variation in abundance of Anopheles (Diptera:Culicidae) in a malaria endemic area in Papua New Guinea

Abundance of anophelines in 10 villages in the Wosera area of Papua New Guinea was monitored during 1990-1993. Of 85,197 anophelines collected in 1,276 paired indoor and outdoor landing catches, 40.4% were Anopheles koliensis Owen, 36.7% An. punctulatus Donitz, 14.3% An. karwari (James), 4.9% An. farauti s.l. Laveran, 3.1%, An, longirostris Brug, and 0.7% An. bancroftii Giles. Maps of average indoor biting rates were produced using a Bayesian conditional autoregressive model which allowed for heterogeneities in sampling effort over time and space. Differences in spatial distributions among species were observed among and within villages and were related to the distribution of larval habitats and vegetation. Abundance of An. punctulatus and An. koliensis decreased with distance from the main waterway and probably from a sago swamp forest at 6 villages in North Wosera. Abundance of An. punctulatus was associated negatively with those of An. farauti s.l., An. longirostris, and An. bancroftii. The latter 3 species also had relatively low ratios of indoor-to-outdoor biting rates, and earlier biting times than An. punctulatus. Human blood indices of at least 0.79 were observed for all species except An. bancroftii. Abundance of all 6 species was correlated temporally with recent rainfall, but An. koliensis, An. karwari, and An. longirostris showed greater temporal variability than the other species. An punctulatus and An. koliensis tended to occur together in time and space (index of association, I = 0.85). Weaker associations were seen between An. farauti s.l. and An. longirostris (I = 0.44) and An. koliensis and An. karwari (I = 0.34). The most frequently collected species occurred together and were concentrated near the Amugu river; the remaining species tended to occur together but in different parts of the Wosera area. The importance of understanding ecological requirements of the different Anopheles vectors and their association with key household and landscape features are discussed in relation to malaria transmission and control.

Lanreotide reduces serum free and total insulin-like growth factor-I after angioplasty

BACKGROUND

Several experiments point to a participating role of insulin-like growth factor-I (IGF-I) in the vascular events leading to restenosis after percutaneous transluminal coronary angioplasty (PTCA).

METHODS AND RESULTS

We measured fasting serum total (extractable) IGF-I in 553 patients in a controlled clinical trial. Half of the patients received continuous subcutaneous infusion of the somatostatin analogue lanreotide from the day before (baseline) and for 4 days after PTCA. We also measured ultrafiltrated serum free IGF-I and IGF-II, total IGF-II, IGF-binding protein-1 (IGFBP-1), IGFBP-3, and insulin in a subgroup of 18 placebo-treated and 20 lanreotide-treated patients. Total IGF-I had decreased by 7% (P < .0001) 1 day after initiation of lanreotide infusion and stayed reduced, whereas no early changes occurred in placebo-treated patients. The same pattern was observed in the subgroup. Free IGF-I decreased significantly from baseline by 22% to 27% (P < .05) in lanreotide-treated patients and increased insignificantly by 10% to 30% (P = .054) in placebo-treated patients. IGFBP-1 increased (P < .05) in both groups postoperatively, but levels in lanreotide-treated patients exceeded (P < .05) those of placebo-treated patients. Lanreotide treatment resulted in minor reductions (P < .05) in free and total IGF-II and IGFBP-3, whereas insulin was unaltered.

CONCLUSIONS

Lanreotide administration acutely decreases circulating total and free IGF-I, the latter relatively more, and increases IGFBP-1. These alterations in the IGF system may participate in the improvement of the long-term outcome after PTCA noted with lanreotide treatment.

Epithelioid sarcoma of the forearm

A case of epithelioid sarcoma of the forearm is described. The radiological and pathological features, natural history of the tumour and its treatment are reviewed.

Transmission dynamics of Wuchereria bancrofti in East Sepik Province, Papua New Guinea

Bancroftian filariasis is endemic in many areas of Papua New Guinea. This study describes the entomologic indices of transmission near Dreikikir in East Sepik Province, Papua New Guinea. A total of 1,735 culicine mosquitoes, including Culex and Mansonia species, were dissected, but none were infected with filarial larvae. In contrast, Anopheles punctulatus and An. koliensis were found to be potential vectors: 7.3% of Anopheles were infected and the mean number of first- to third-stage larvae per infected mosquito was 2.7. Transmission indices varied significantly in five villages located within a 50-km radius of each other. Annual biting rates ranged from 4,789 to 48,020 bites/person/year; annual infective biting rates from 15 to 836/person/year; and annual transmission potential from 31 to 2,340 third-stage larvae/person/year. Monthly transmission potential and monthly infective biting rate varied significantly in each village, with the highest indices of transmission observed in villages nearest sites where puddles formed in river beds during the dry season. These data indicate that there is small area variation in the intensity and temporal pattern of filariasis transmission and that culicine mosquitoes are not important vectors of W. bancrofti in this area.

The late biting habit of parous Anopheles mosquitoes and pre-bedtime exposure of humans to infective female mosquitoes

Using the all-night landing catch method (18:00-06:00) we showed, for Anopheles gambiae in Sierra Leone and A. punctulatus in Papua New Guinea, that parous females have a tendency to bite later than nulliparous ones. The biting habit of sporozoite-infected A. punctulatus was also investigated. The sporozoite rates for Plasmodium falciparum and P. vivax were 1.8 and 1.4% respectively, but only one (1.3%) of 76 females infected with P. falciparum was caught between 18:00 and 21:00. A significantly higher proportion (11.6%) of mosquitoes infected with P. vivax was caught in the same period. The late biting habit of mosquitoes infected with P. falciparum is discussed in relation to the differential biting habits of parous and nulliparous females. We conclude with a hypothesis that, in areas where Anopheles mosquitoes have a late-biting cycle and low parous rate, exposure to mosquitoes infected with P. falciparum during the pre-bedtime period (18:00-22:00) is very low. This hypothesis could explain why insecticide-treated bed nets protect children better in areas of seasonal transmission, where nulliparous females tend to predominate, than in areas of perennial transmission, where parous females are usually more numerous. The same hypothesis is compatible with the finding in Papua New Guinea that insecticide-impregnated bed nets are more protective against P. falciparum than against P. vivax malaria.

Evidence of HLA class II association with antibody response against the malaria vaccine SPF66 in a naturally exposed population

The antibody response against the malaria vaccine SPf66 and against circumsporozoite (CS) protein has been tested in immune adults from a malaria endemic area in Papua New Guinea. All individuals were genotyped for the HLA class II DQB1 and DRB1 loci, and the humoral response was analyzed with respect to the identified class II alleles. At each locus, only three alleles were frequent, namely DRB1*11, *15, and *16, and DQB1*0301, *0502, and *0601. Antibodies against SPf66 and CS protein were found in 84% and 79% of the individuals, respectively. A strong negative association was detected between the humoral response against SPf66 and DRB1*15 and DQB1*0601. A positive association of the response was observed with DRB1*11 and DQB1*0301. After analysis with a multiple regression model in which all alleles were included simultaneously, only DRB1*15 remained significantly associated with low antibody responses. This suggests that nonresponders may be expected after immunization with SPf66 in certain populations.

Humoral and cell-mediated immunity to the Plasmodium falciparum ring-infected erythrocyte surface antigen in an adult population exposed to highly endemic malaria

A parasitological and immunological survey was carried out in an area in Papua New Guinea highly endemic for malaria. Two hundred fourteen adult individuals were selected for studies to assess their immune responses against the malaria vaccine candidate ring-infected erythrocyte surface antigen (RESA). Total immunoglobulin G (IgG) antibodies directed against RESA as well as specific IgG1, IgG2, and IgG3 antibodies were determined. Humoral responses directed against RESA were frequent in all IgG subclasses. Only IgG3 responses were found to be age dependent. Total anti-RESA IgG antibodies were not correlated with protection against malaria as measured by parasite prevalence, parasite density, or health center attendance. In contrast, cytophilic antibodies (IgG1 and IgG3) were associated with reduced Plasmodium falciparum prevalence and reduced health center attendance. T-cell proliferation in general was low and very infrequent. No correlation between humoral and cellular immune responses could be found. Parasite density, parasite prevalence, and health center visits tended to be reduced in individuals with good humoral and cell-mediated immune responses.

Flavoxate treatment of micturition disorders accompanying benign prostatic hypertrophy: a double-blind placebo-controlled multicenter investigation

To investigate the effect of flavoxate (Urispadol) treatment on patients with symptomatic benign prostatic hypertrophy (BPH), with the main weight on the irritative symptoms, a randomized, double-blind, parallel-group, placebo-controlled and multicenter investigation was carried out. Seventy patients entered the study, 37 were allocated to flavoxate treatment on a daily dose of 1,200 mg (400 mg t.i.d.) for 12 weeks, and 33 patients were allocated to placebo treatment. In spite of a sufficient power, the study did not discriminate the two treatment groups in a statistically significant way (p > 0.05), when considering the main endpoints: the irritative symptom score and the global patient evaluation. Conservative treatment of micturition disorders accompanying BPH with flavoxate in doses of 1,200 mg/day cannot be recommended for clinical use.