Black-white unions: West Indians and African Americans compared

In this research we use 1990 PUMS data to compare the propensity for unions between African Americans and native whites with the propensity for unions between British West Indians and native whites. In addition, we distinguish women and men. Descriptive statistics indicate that West Indians, with the exception of men who arrived as adults, are more likely than African Americans to have white partners. After the introduction of controls for several correlates of intermarriage, however, West Indian men of any generation have lower exogamy rates than African American men, while exogamy rates are higher among West Indian women who arrived as children or who were born in the United States than among African American women. Thus we find no consistent evidence of greater exogamy for British West Indians than for African Americans.

Plasma L-arginine is markedly reduced in pregnant women affected by preeclampsia

The objective of this study was to determine the concentration of free L-amino acids and in particular of L-arginine in the plasma of pregnant women affected by preeclampsia compared to healthy pregnant women in order to know if an alteration in the concentrations of these amino acids occurs in preeclamspia. Twelve pregnant women affected by preeclampsia and twelve pregnant control women, ages 28-35 years old and at the 35-36 weeks of pregnancy were studied. The blood analysis of free amino acids was carried out by using a high performance liquid chromatographic (HPLC) fluorometric method and OPA-NAC as derivatizing agent for the amino acid determination. In the blood of women affected by preeclampsia L-arginine is markedly reduced compared to controls (about five-fold lower, P<0.01). The other amino acids also are significantly reduced, but to lesser extents (about 1.5 times lower, P<0.05). Thus, the determination of L-arginine in the blood of pregnant women could potentially constitute an additional marker for the early diagnosis of preeclampsia.

Transmodulation of epidermal growth factor receptor mediates IL-1 beta-induced MMP-1 expression in cultured human keratinocytes

Ultraviolet (UV) irradiation causes human skin aging and skin cancer through the activation of matrix metalloproteinases (MMPs) which are responsible for the degradation of collagen and tumor progression in human skin. The molecular mechanisms of UV-induced MMPs are yet to be defined. Our previous studies and others suggest that i) the transient activation of cell surface receptors and subsequent activation of MAP kinase cascade contributes to the transcriptional up-regulation of MMPs; and ii) UV-induced expression of pro-inflammatory cytokines such as IL-1 beta and TNF-alpha may also account for the expression of MMPs. However, signaling pathway through which cytokines induce MMP expression remains to be unraveled. In this study, we investigated the pathway that leads to the IL-1 beta-induced up-regulation of MMP-1 in human keratinocytes. IL-1 beta activated epidermal growth factor (EGF) receptor in cultured human keratinocytes in a time- and dose-dependent manner. IL-1 beta-induced EGF receptor tyrosine phosphorylation started at 5 min and peaked at 10 min and remained elevated up to 40 min post IL-1 beta treatment. EGF receptor kinase inhibitor PD153035 and AG1478 inhibited IL-1 beta-induced EGF receptor tyrosine phosphorylation. To test the effect of EGF receptor transactivation on downstream components, we examined the ERK activation by IL-1 beta. We found that IL-1 beta-induced ERK phosphorylation, PD153035 and MEK inhibitor PD98059 blocked IL-1 beta-induced ERK activity. Furthermore, both inhibitors also dramatically reduced IL-1 beta-induced expression of c-jun and c-fos mRNA which are required for up-regulation of MMPs. EGF receptor kinase inhibitor PD153035 and AG1478 and MEK inhibitor PD98059 also blocked IL-1 beta induction of MMP-1 in cultured human keratinocytes. Collectively, our data indicate that IL-1 beta-induced expression of MMP-1 is mediated by transactivation of EGF receptor and through ERK pathway in human keratinocytes.

Definitions of allied health services in urban community contexts: consumer perspectives

This study, as part of a larger project designed to increase allied health services to underserved urban community agencies, focussed on understanding how consumers defined the services provided in community agencies. Consumers were asked to describe what they defined as service and what constituted good service provision. Qualitative methods were used to conduct key-informant interviews and focus groups with consumers and staff at six community agencies representing different underserved populations, including ethnic and racial minority groups, the homeless, and individuals with disabilities living in the community. Four major themes emerged across the data: 1) the struggle to maintain a stable life with a chronic illness or disability; 2) services need to help solve life challenges; 3) the challenge of accessing and maintaining services; and 4) the need for a peer community. Data analysis revealed that services are difficult to access within and outside community agencies, services need to address short-term as well as long-term issues, and services in the community are still driven by a professional or expert model despite the availability of peer models. Recommendations for health professionals working in community settings are provided.

EGF receptor crosstalks with cytokine receptors leading to the activation of c-Jun kinase in response to UV irradiation in human keratinocytes

Ultraviolet (UV) irradiation causes photoageing through induction of matrix-degrading metalloproteinases (MMP), which are upregulated by activator protein-1 (AP-1) (Jun/Fos). The c-Jun kinase activity proves to be critically important in the regulation of AP-1 activity. Our previous studies showed that UV irradiation activates epidermal growth factor receptor (EGFR) and cytokine receptors leading to the activation of c-Jun kinase in cultured human skin keratinocytes in vitro and in human skin in vivo. However, the mechanism of UV-induced cell surface receptor activation and the crosstalk among growth factor receptor and cytokine receptors were not fully investigated. This study showed that UV (30 mJ/cm(2))-induced EGFR tyrosine phosphorylation in a manner similar to EGF (100 ng/ml), or IL-1beta (10 ng/ml) in cultured human keratinocytes. In all cases, EGFR tyrosine phosphorylation was completely inhibited by pretreatment of PD153035 (100 nM, 1 h). Also observed was that UV induced autophosphorylation of interleukin 1 receptor associated kinase (IRAK) in a manner analogous to IL-1beta or EGF. In both UV and EGF cases, the phosphorylation of IRAK was inhibited by pretreatment of PD153035. However, IL-1beta-induced IRAK activation was not affected by PD153035. In vitro kinase assay using GST-c-Jun as a substrate revealed that pretreatment of PD153035 completely inhibited UV- and IL-1-induced c-Jun kinase activity in cultured keratinocytes. Taken together, the above data suggest that EGFR plays dominant role in the crosstalk among growth factor receptor and cytokine receptors leading to the activation of c-Jun kinase upon UV irradiation, and that EGFR could be one of the targets for clinical and cosmetical prevention of UV-induced skin aging.

Radiotherapy, concomitant protracted-venous-infusion 5-fluorouracil, and surgery for ultrasound-staged T3 or T4 rectal cancer

BACKGROUND

A prospective study was undertaken to evaluate the response and toxicity of neoadjuvant chemoradiotherapy for ultrasound-staged T3 or T4 rectal cancer.

PATIENTS AND METHODS

Since 1995, 30 patients (18 males; median age, 56 (range, 25-83) years) have received preoperative chemoradiotherapy for ultrasound-staged T3 or T4 rectal cancer. All patients underwent an endorectal ultrasound, CT scan, and review in our multidisciplinary Gastrointestinal Tumor Board before treatment. All patients had pathology-demonstrated invasive adenocarcinoma of the rectum. Eleven patients were Stage T3N0, 14 were T3N1, and five were T4N1. Patients received radiotherapy to the primary tumor and draining lymph nodes (45 Gy) followed by a tumor boost (50.4-54 Gy). Protracted-venous-infusion 5-fluorouracil (225 mg/m2 per day, seven days per week) was administered throughout treatment. Surgical resection was performed six to ten weeks after completing chemoradiotherapy. Using endorectal ultrasound measurements, the primary tumor was a median of 4 (range, 0-12) cm from the anal verge, encompassed 50 (range, 20-90) percent of the rectal circumference, and was 6 (range, 3-12) cm in diameter.

RESULTS

No Grade 4 toxicity was observed during chemoradiotherapy. Three patients experienced Grade 3 toxicity (diarrhea), and four patients required a treatment interruption of greater than three days. All patients completed at least 90 percent of the prescribed radiotherapy dose. All patients underwent surgical resection. Ninety-four percent had clear surgical margins. All pathologic specimens had significant evidence of necrosis, hyalinization, and fibrosis. Thirty-three percent of the specimens had a complete pathologic response (defined as no evidence of viable tumor cells). Of the 19 patients with ultrasound-staged N1 disease, only five had pathologic evidence of nodal involvement after chemoradiotherapy. Of the 25 patients with ultrasound-staged T3 disease, pathologic staging revealed eight with T0, two with T1, five with T2, and ten with T3 disease. Of the five patients with ultrasound-staged T4 disease, pathologic staging revealed two with T0, one with T2, and two with T3 disease. No patient developed progressive disease while on treatment. Two patients have experienced local failure at 6 and 20 months, and one patient failed in the liver at seven months. Twenty-seven patients remain free of disease with a median follow-up of 20 (range, 3-53) months.

CONCLUSION

Our experience suggests that preoperative chemoradiotherapy is well tolerated, down-stages tumors, and sterilizes regional lymph nodes.

Preoperative chemoradiation for marginally resectable adenocarcinoma of the pancreas

Only 10% to 20% of patients with pancreatic cancer are considered candidates for curative resection at the time of diagnosis. We postulated that preoperative chemoradiation therapy might promote tumor regression, eradicate nodal metastases, and allow for definitive surgical resection in marginally resectable patients. The objective of this study was to evaluate the effect of a preoperative chemoradiation therapy regimen on tumor response, resectability, and local control among patients with marginally resectable adenocarcinoma of the pancreas and to report potential treatment-related toxicity. Patients with marginally resectable adenocarcinoma of the pancreas (defined as portal vein, superior mesenteric vein, or artery involvement) were eligible for this protocol. Patients received 50.4 to 56 Gy in 1.8 to 2.0 Gy/day fractions with concurrent protracted venous infusion of 5-fluorouracil (250 mg/m2/day). Reevaluation for surgical resection occurred 4 to 6 weeks after therapy. Fifteen patients (9 men and 6 women) completed preoperative chemoradiation without interruption. One patient required a reduction in the dosage of 5-fluorouracil because of stomatitis. Acute toxicity from chemoradiation consisted of grade 1 or 2 nausea, vomiting, diarrhea, stomatitis, palmar and plantar erythrodysesthesia, and hematologic suppression. CA 19-9 levels declined in all nine of the patients with elevated pretreatment levels. Nine of the 15 patients underwent a pancreaticoduodenectomy, and all had uninvolved surgical margins. Two of these patients had a complete pathologic response, and two had microscopic involvement of a single lymph node. With a median follow-up of 30 months, the median survival for resected patients was 30 months, whereas in the unresected group median survival was 8 months. Six of the nine patients who underwent resection remain alive and disease free with follow-up of 12, 30, 30, 34, 39, and 72 months, respectively. Preoperative chemoradiation therapy is well tolerated. It may downstage tumors, sterilize regional lymph nodes, and improve resectability in patients with marginally resectable pancreatic cancer. Greater patient accrual and longer follow-up are needed to more accurately assess its future role in therapy.

UV-induced expression of GADD45 is mediated by an oxidant sensitive pathway in cultured human keratinocytes and in human skin in vivo

The expression of GADD45 was examined in cultured skin keratinocytes and in human skin in vivo following UV irradiation. Northern blot analysis revealed that UV-induced the expression of GADD45 (alpha, beta, gamma) in a time- and dose-dependent manner. Messenger RNA of GADD45 (alpha, beta, gamma) increased within 30 min, peaked at 4 h and remained elevated for at least 8 h following UV irradiation in vitro and in vivo. Maximal induction of GADD45alpha was approximately 5-fold compared to the level in sham-irradiated controls. Similarly H2O2 and IL-1 also induced GADD45alpha expression in cultured human keratinocytes. The kinetics of induction of GADD45alpha by H2O2, IL-1beta and UV were very similar. Interestingly, UV-induced GADD45alpha expression was inhibited by diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, and antioxidant, N-acetyl-L-cysteine (NAC), indicating the involvement of reactive oxygen species in UV signaling. Previously we have shown that EGF receptor activation by UV is prerequisite for subsequent activation of NADPH oxidase and generation of reactive oxygen species. We therefore examined the effect of EGF receptor inhibitor on UV-induced GADD45alpha expression. Our results showed that PD168393, a potent EGF receptor inhibitor, blocked UV-induced GADD45alpha expression. Collectively, our data suggest that UV-induced GADD45alpha expression occur via an EGF receptor-mediated oxidative pathway sensitive to antioxidant regulation.

The sex-linked fidget mutation abolishes Brn4/Pou3f4 gene expression in the embryonic inner ear

We have demonstrated that the phenotype of the mouse mutant sex-linked fidget ( slf ) is caused by developmental malformations of the inner ear that result in hearing loss and vestibular dysfunction. Recently, pilot mapping experiments suggested that the mouse Brn4 / Pou3f4 gene co-segregated with the slf locus on the mouse X chromosome. These mapping data, in conjunction with the observation that the vertical head-shaking phenotype of slf mutants is identical to that observed in mice with a targeted deletion of the Brn4 gene, suggested that slf is a mutant allele of the Brn4 gene. In this paper, we have identified the nature of the slf mutation, and demonstrated that it is an X chromosomal inversion with one breakpoint close to Brn4. This inversion selectively eliminates the expression of the Brn4 gene in the developing inner ear, but not the neural tube. Finally, these results demonstrate that the slf mutation is a good mouse model for the most prevalent form of X-linked congenital deafness in man, which is associated with mutations in the human Brn4 ortholog, POU3F4.

Abdominal obesity reduction in indigenous men

OBJECTIVES

To assess the effectiveness of a men's 'waist loss' program over one year in Indigenous men.

DESIGN

Pre-and post-test measurements of 47 Indigenous men on four island groups in the Torres Strait region of Northern Australia involved in a version of the 'GutBuster' program, modified by and for Indigenous men.

RESULTS

Weight, waist and hip size of 47 men, and body fat estimated from electrical impedence measures of 27 men, were compared at baseline, after approx 2 months, approx 6 months and approx one year. Average weight loss was 3.3 kg (3.5%), and waist loss 4.0 cm (3.5%). The average percentage decrease in fat mass (FM) was 10.8%. An environmental audit technique highlighted modifications needed to the environment to assist behaviour change.

CONCLUSIONS

Education-behaviour change interventions of this kind may offer opportunities for health improvements in Indigenous men.

NMR probe for the simultaneous acquisition of multiple samples

A dual channel probe for the simultaneous acquisition of NMR data from multiple samples has been developed. This multiplex probe consists of two noninteracting sample coils that are each capable of detecting NMR signals at the same resonant frequency with good sensitivity and resolution. 13C free induction decays for the two samples, methanol (13C, 99%) and carbon tetrachloride (13C, 99%), were acquired simultaneously at 75.44 MHz using a single transmitter pulse and separate NMR receivers. S/N measurements are comparable to those observed using single coils. No evidence of cross talk is evident in the spectra even after considerable signal averaging. The probe demonstrates the feasibility of significant parallelism in NMR, which will be of interest in situations where high throughput analysis is desired.

Free D- and L-amino acids in ventricular cerebrospinal fluid from Alzheimer and normal subjects

Free D-Ser, D-Asp and total D-amino acids were significantly higher (p < 0.05) in Alzheimer (AD) ventricular CSF than in normal CSF. There was no significant difference in the total L-amino acids between AD and normal CSF, but L-Gln and L-His were significantly higher (p < 0.05) in AD-CSF. The higher concentrations of these D- and L-amino acids in AD ventricular CSF could reflect the degenerative process that occurs in Alzheimer's brain since ventricular CSF is the repository of amino acids from the brain.

Nursing management of the patient with bone metastases

OBJECTIVES

To review the problem of bone metastases and strategies aimed at the management of bone metastases.

DATA SOURCES

Review articles, book chapters, research studies, and clinical practice.

CONCLUSIONS

As patients survive for longer periods, effective management of bone metastases becomes critical to maintaining or improving quality of life. Controlling pain, preventing fractures and oncologic emergencies, and promoting mobility and function are the outcomes of successful management.

IMPLICATIONS FOR NURSING PRACTICE

Use of a clinical algorithm may assist the nurse in identifying bone metastases and managing the clinical sequelae, such as pain.

Analysis of meiotic chromosome pairing in the female mouse using a novel minichromosome

Analysis of a radiation-induced minichromosome using classical cytogenetic techniques and fluorescence in situ hybridization (FISH) has shown this element to be composed primarily, if not entirely, of repeat sequence DNAs that are common to the ends of all chromosomes in the mouse genome. This novel chromosome has been used to examine further the role of centromeric and telomeric DNA sequences in the initiation of homologous chromosome pairing and synapsis in female germ cells. In pachytene oocytes of a fetus carrying two copies of the minichromosome, it was found that these elements were collocalized, but had not undergone synapsis, in half of the cells analysed. The minichromosomes formed a synaptonemal complex in approximately 14% of oocytes. Overall, therefore, the minichromosomes showed a surprising ability to achieve the first phase of homologous chromosome pairing, i.e. collocalization, despite their dearth of chromosome-specific DNA sequences. It is suggested that this collocalization largely results from the tendency of mouse chromosome ends to form centromeric and telomeric clusters at zygotene. The observations here provide support for the proposition that clustering of chromosome ends in early meiosis fosters pairing interactions and synapsis.

Retinoic acid receptor beta regulates growth and differentiation in human pancreatic carcinoma cells

BACKGROUND & AIMS

Retinoic acid receptor beta (RAR beta) expression is lost or decreased during malignant transformation in human pancreatic adenocarcinoma. The aim of this study was to evaluate the role of RAR beta expression in the propagation of a malignant phenotype in human pancreatic carcinoma cells.

METHODS

Overexpression of RAR beta in the human pancreatic carcinoma cell line DAN-G was achieved by selecting stable transfected cell clones. Genomic integration and expression were verified by Southern and Northern blotting and electrophoretic mobility shift assays. Growth was determined by cell number and xenografts transplanted into nude mice. Differentiation was examined by immunohistochemistry.

RESULTS

Overexpression of RAR beta in DAN-G cells inhibited cellular proliferation in vitro and in vivo. Furthermore, RAR beta overexpression resulted in induction of cellular differentiation in xenografted tumors as evidenced by increased tumor cell expression of duct cell differentiation markers carcinoembryonic antigen (CEA), CA19-9, and cytokeratin 7.

CONCLUSIONS

Decreased expression of RAR beta plays a key role in the maintenance of a malignant phenotype in human pancreatic adenocarcinoma and therefore represents a novel target for experimental strategies in the treatment of pancreatic cancer patients.

Clinical decision making based on radionuclide determined ejection fraction in oncology patients

Decreased left ventricular ejection fraction (LVEF) is a relative contraindication for the use of potentially cardiotoxic chemotherapy. A resting LVEF of 50% is usually used as the lower limit of normal values. The decision to change chemotherapy, however, is complex and is affected by many factors, including ejection fraction.

METHODS

To determine how LVEF data were used by clinical oncologists in clinical decision making, we performed a retrospective analysis of patients referred for ejection fraction measurements from the hematology/oncology divisionS of Stanford University from March 1992 through March 1995. The records of 565 patients treated with potentially cardiotoxic chemotherapy were evaluated.

RESULTS

LVEFs < 50% were found in 153 patients. The charts of patients with reduced ejection fractions were reviewed to determine if the radionuclide measurement resulted in either discontinuation of the cardiotoxic agent or substitution of a less cardiotoxic drug or mode of administration. These specific changes in therapy occurred in only 43 of the 153 (28%) patients with ejection fractions below 50%; 24 of the 43 (57%) had ejection fractions < or = 40%. Patients with lower ejection fraction values were more likely to have their therapy changed than those with LVEFs close to normal. Patients with ejection fractions < or = 30 generally had cardiotoxic agents discontinued. Of patients who had a resting LVEF < 50% and whose therapy was not changed, 81% had a normal increase in LVEF with exercise.

CONCLUSION

In clinical practice at our institution, ejection fraction < 50% is not used as an absolute contraindication to cardiotoxic chemotherapy. When the LVEF is less than 40%, potentially cardiotoxic therapy is most often discontinued or omitted. Radionuclide evidence of cardiac reserve may account for decisions to continue cardiotoxic agents despite ejection fractions < 50% in the majority of patients. Further study will be needed to establish standard criteria. Reserve function, as measured by the change in ejection fraction from rest to stress may be an important parameter used by oncologists to help select patients for continued therapy in spite of a reduced ejection fraction. Our results argue that use of fixed criteria may be too restrictive.

Bone metastases: Part I--Pathophysiology

Many cancers (especially breast, prostate, and lung cancers) metastasize to the bone. The most frequent site of bone involvement is the axial skeleton (i.e., cranium, ribs, spine, and pelvis). The sequelae of bone metastases include pain, hypercalcemia, pathologic fractures, and spinal cord compression. As patients survive for longer periods, effective management of bone metastases becomes critical to maintaining or improving quality of life. Controlling pain, preventing fractures and oncologic emergencies, and promoting mobility and function are the outcomes of successful management. Use of a clinical algorithm can assist the nurse in identifying bone metastases and managing the clinical sequelae. Knowledge of the pathophysiology and the ability to assess bone metastases will contribute to the nurse's ability to manage the clinical problems and to improve the quality of life of patients with cancer.

Bone metastases: Part II--Nursing management

Nurses play a crucial role in identifying bone metastases and managing clinical sequelae, such as pain. Understanding the metastatic process is necessary for delivering effective nursing care. Part I of this article described the pathophysiology and assessment. Part II will provide an overview of the nursing management of the sequelae of bone metastases, including pain, pathologic fractures, spinal cord compression, hypercalcemia, and anemia. Risk factor identification can lead to prevention and early detection of these clinically significant problems. Clinical management of bone metastases will contribute to the nurse's ability to improve the quality of life of patients with cancer.

Signal amplification in the detection of single-copy DNA and RNA by enzyme-catalyzed deposition (CARD) of the novel fluorescent reporter substrate Cy3.29-tyramide

We demonstrate that the CAtalyzed Reporter Deposition method (CARD), utilizing the novel fluorescent reporter Cy3.29-tyramide, is successful in the Fluorescent in Situ Hybridization (FISH) detection of RNA and single-copy DNA. Histone 4 expression is detected in RNA extracts of 5-phase, synchronized HeLa cells by dot-blot analysis. Gene expression of histone 4 in HeLa cells is demonstrated by FISH via CARD, utilizing oligonucleotide probes. Fluorescence intensity measurements on CARD-amplified histone 4 RNA detection showed (a) a 25-fold amplification of the signal brightness by biotinylated oligonucleotide probes and (b) a sixfold amplification of the signal brightness by horseradish peroxidase (HRP)-labeled histone 4 probes vs the directly stained control. The sensitivity of the CARD method is demonstrated by the FISH detection of single-copy DNA on human corneal fibroblast and HeLa S5 interphase nuclei. Chromosomal localization of the single copy DNA is demonstrated on HeLa S3 metaphase chromosome spreads.

Cumulative risk of second primary cancers in women with index primary cancers of uterine cervix and incidence of lower anogenital tract cancers, Michigan, 1985-1992

A retrospective cohort study of women with cancers of the lower anogenital tract was derived from the Michigan Tumor Registry records for the years 1985-1992. Incidence rates of invasive cervical, vulvar, vaginal and anal cancers were analyzed with respect to age, race, year of diagnosis, stage at diagnosis, and histopathology. The incidence of metachronous primary cancers following initial primaries of the cervix was also investigated. Anogenital cancers constituted about 4% of all cancers in Michigan women between 1985 and 1992. Age-adjusted incidence rates per 100,000 women per year for each site were found to be as follows: 10.1 (cervix), 1.9 (vulva), 1.0 (vagina), and 0.6 (anus). The incidence rates of women in the United States for cancers in the anogenital region were higher in blacks than in whites, with the exception of vulvar cancer. U.S. blacks were more likely to develop squamous cell carcinomas, but less likely to develop adenocarcinomas of the cervix and vagina when compared to whites. Over the 5- to 8-year follow-up period, 6.5% of the women with index cases of cervical cancer developed second primary cancers. This represented a 40% increase in the risk of incident primary cancers compared to the risk in the general population of Michigan women. The significant occurrence of second primaries of the vagina following index primaries of the cervix suggests a shared etiology, such as infection with human papillomavirus. The incidences of cancers related to smoking, including cancers of the urinary bladder, lung/bronchus, and lower anogenital tract were also increased.

Prospects, problems, and prerequisites for national health examination surveys in developing countries

Design options for the development of health information systems are evaluated. The health examination survey is found to be an appropriate method for meeting data needs for health planning, program design, and evaluation activities in developing countries. The model proposed is a national cross-sectional prevalence survey employing both interviews and physical examinations to produce a health status profile of a countries population. Examination data are objective, internationally comparable, and not dependent upon reports of clinical encounters in the population. Limitations inherent to health examination surveys are reviewed in reference to their potential in developing countries. Not all countries may be able to conduct health examination surveys; criteria are presented to assist in evaluation of the feasibility of application in specific countries.