Dengue vaccine acceptance and willingness to pay: a systematic review and meta-analysis

OBJECTIVE

Dengue is the most important human vector-borne disease in terms of disease burden. A first dengue vaccine has recently been licenced, and others are in advanced stages of development. However, to date, none of these vaccines has achieved balanced efficacy and safety for all dengue serotypes. The aim of this systematic review and meta-analysis was to assess the global acceptance and willingness to pay for unspecified dengue vaccines.

METHODS

This systematic review and meta-analysis included cross-sectional and cohort studies that reported values for vaccine acceptance (percentage) and willingness to pay for currently available or hypothetical vaccines. These values were pooled using random-effects models for the acceptance, while weighted linear regression was chosen for willingness to pay. Heterogeneity between studies was assessed using prediction intervals (PIs), and a domain-based tool was used to assess the risk of bias. Subgroup and sensitivity analyses were performed where appropriate. This study was registered with PROSPERO (CRD42021255784).

RESULTS

We included 19 studies from the Americas and Asia in the quantitative meta-analysis. The risk of bias was mainly related to the selection of participants and to the assumptions about the safety and efficacy of the vaccines. The percentage of vaccine acceptance was 88.3% (95% CI: 81.0%-93.0%), with some heterogeneity between studies (80% PI: 52.9%-98.1%). Willingness to pay was US$ 46.7 (95% CI: 25.9-67.5) per vaccine recipient. There were differences between continents, with higher acceptance in the Americas.

CONCLUSIONS

We were able to obtain global estimates of vaccine acceptance and willingness to pay and identify the associated factors that influence these values. This knowledge is relevant for the planning of future vaccination strategies.

Poster Session: A unifying framework for perceptual decision-making

Perceptual decision making (PDM) has been studied using two approaches. Threshold measurement is predominant used in psychophysics, while reaction times (RT) with associated models have been used to estimate components of PDM (i.e., drift rate). To test if these two approaches reflect overlapping mechanisms, we conducted 3 experiments: a motion, a static orientation, and a dynamic orientation task. DT is the shortest stimulus presentation time sufficient to make accurate perceptual decisions. RTs and choices were fitted by a drift diffusion model (DDM). We expected a close relationship between DTs and drift rates, allowing us to accurately predict DTs from RT. In the motion task, we found a close relation between the empirical DTs and the DTs predicted by the DDM. Surprisingly, in the static task, there was little correlation between the two; DTs, improved monotonically with higher contrast, but drift rates saturated at 6%. We hypothesize that this mismatch is due to the information being available immediately in the static task, without needing to accumulate new evidence. Thus, we developed a novel dynamic orientation task that mimics the dynamic nature of the motion task and found a similar relation between DTs and drift rates. In summary, we show a close link between DTs and drift rate for the two dynamic tasks. This result supports the conceptualization of drift rate as a proxy for perceptual sensitivity but only for task where new information becomes available over time.

Old-age-induced obesity reversed by a methionine-deficient diet or oral administration of recombinant methioninase-producing Escherichia coli in C57BL/6 mice

Obesity increases with aging. Methionine restriction affects lipid metabolism and can prevent obesity in mice. In the present study we observed C57BL/6 mice to double their body weight from 4 to 48 weeks of age and become obese. We evaluated the efficacy of oral administration of recombinant-methioninase (rMETase)-producing E. coli (E. coli JM109-rMETase) or a methionine-deficient diet to reverse old-age-induced obesity in C57BL/6 mice. Fifteen C57BL/6 male mice aged 12-18 months with old-age-induced obesity were divided into three groups. Group 1 was given a normal diet supplemented with non-recombinant E. coli JM109 cells orally by gavage twice daily; Group 2 was given a normal diet supplemented with recombinant E. coli JM109-rMETase cells by gavage twice daily; and Group 3 was given a methionine-deficient diet without treatment. The administration of E. coli JM109-rMETase or a methionine-deficient diet reduced the blood methionine level and reversed old-age-induced obesity with significant weight loss by 14 days. There was a negative correlation between methionine levels and negative body weight change. Although the degree of efficacy was higher in the methionine-deficient diet group than in the E. coli JM109-rMETase group, the present findings suggested that oral administration of E. coli JM109-rMETase, as well as a methionine-deficient diet, are effective in reversing old-age-induced obesity. In conclusion, the present study provides evidence that restricting methionine by either a low-methionine diet or E. coli JM109-rMETase has clinical potential to treat old-age-induced obesity.

Hair follicle associated pluripotent (HAP) stem cells jump from transplanted whiskers to pelage follicles and stimulate hair growth

Stimulation of hair growth in hair loss has been a difficult goal to achieve. Hair follicle-associated pluripotent (HAP) stem cells express nestin and have been shown to differentiate to multiple cell types including keratinocytes, neurons, beating cardiac muscles and numerous other cell types. HAP stem cells originate in the bulge area of the hair follicle and have been shown to migrate within and outside the hair follicle. In the present study, the upper part of vibrissa follicles from nestin-driven green-fluorescent protein (GFP) transgenic mice, containing GFP-expressing HAP stem cells, were transplanted in the dorsal area of athymic nude mice. Fluorescence microscopy and immunostaining showed the transplanted HAP stem cells jumped and targeted the bulge and hair bulb and other areas of the resident nude mouse pelage follicles where they differentiated to keratinocytes. These results indicate that transplanted nestin-GFP expressing HAP stem cells jumped from the upper part of the whisker follicles and targeted nude-mouse hair follicles, which are genetically deficient to grow normal hair shafts, and differentiated to keratinocytes to produce normal mature hair shafts. The resident nude-mouse pelage follicles targeted by jumping whisker HAP stem cells produced long hair shafts from numerous hair follicles for least 2 hair cycles during 36 days, demonstrations that HAP stem cells can stimulate hair growth. The present results for hair loss therapy are discussed.

Peritoneal Metastases in a Patient-derived Orthotopic Xenograft (PDOX) Model of Colon Cancer Imaged Non-invasively via Red Fluorescent Protein Labeled Stromal Cells

BACKGROUND/AIM

Patient-derived orthotopic xenograft (PDOX) models have patient-like clinical features and may be imaged, in case of some cancers, by passaging of the tumors through transgenic nude mice expressing red-fluorescent protein (RFP) where they stably acquire RFP expressing stroma. The aim of the present study was to quantify red fluorescent area and intensity in colon-cancer peritoneal metastases in PDOX models in non-transgenic nude mice after passage in RFP transgenic nude mice by non-invasive external fluorescence imaging.

MATERIALS AND METHODS

Tumor fragments originating from a colon cancer patient with peritoneal metastases were implanted in transgenic RFP nude mice. Resultant tumors were harvested, and fragments were implanted in the same strain a second time. Passaged tumors stably acquired RFP-expressing stroma from their transgenic hosts. The tumor with RFP-expressing stromal cells were harvested and implanted orthotopically in non-transgenic nude mice. At eight weeks post-implantation, non-invasive external RFP images were obtained. RFP area and intensity were measured and correlated with tumor weight and volume.

RESULTS

Metastatic patient colon cancer can be stably and brightly labeled by passage in transgenic RFP-expressing nude mice such that tumor growth could be non-invasively imaged. Tumor growing could be non-invasively imaged when passaged to non-transgenic nude mice. A strong correlation between fluorescence intensity and area values with tumor weight and volume were established by external fluorescence imaging.

CONCLUSION

This new tumor model of metastatic colon cancer can be used to evaluate novel therapeutics in real time for this recalcitrant disease.

Tumor-targeting Salmonella typhimurium A1-R in combination with doxorubicin eradicate soft tissue sarcoma in a patient-derived orthotopic xenograft (PDOX) model

A patient with high grade undifferentiated pleomorphic soft-tissue sarcoma from a striated muscle was grown orthotopically in the right biceps femoris muscle of mice to establish a patient-derived orthotopic xenograft (PDOX) model. Twenty PDOX mice were divided into 4 groups: G1, control without treatment; G2, Salmonella typhimurium (S. typhimurium)A1-R administered by intratumoral (i.t.) injection once a week for 4 weeks; G3, doxorubicin (DOX) administered by intraperitoneal (i.p.) injection once a week for 4 weeks; G4, S. typhimurium A1-R (i.t.) administered once a week for 2 weeks followed by i.p. doxorubicin once a week for 2 weeks. On day 25 from the initiation of treatment, tumor volume in G2, G3, and G4 was significantly lower than G1. Mice found without gross tumor included one mouse (20%) in G2; one mouse (20%) in G3; and 3 mice (60%) in G4. Body weight loss did not significantly differ between the 3 treated groups or from the untreated control. Histological examination revealed eradication of tumor only in G4 where mice were treated with S. typhimurium A1-R followed by DOX. Our present study indicates future clinical potential of combining S. typhimurium A1-R with chemotherapy such as DOX for soft tissue sarcoma patients.

Color-coded imaging of spontaneous vessel anastomosis in vivo

Vessel anastomosis is important in tumor angiogenesis as well as for vascularization therapy for ischemia and other diseases. We report here the development of a color-coded imaging model that can visualize the anastomosis between blood vessels of red fluorescent protein (RFP)-expressing vessels in vascularized Gelfoam® previously transplanted into RFP transgenic mice and then re-transplanted into nestin-driven green fluorescent protein (ND-GFP) mice where nascent blood vessels express GFP. Gelfoam® was initially transplanted subcutaneously in the flank of transgenic RFP nude mice. Skin flaps were made at 14 days after transplantation of Gelfoam® to allow observation of vascularization of the Gelfoam® using confocal fluorescence imaging. The implanted Gelfoam® became highly vascularized with RFP vessels. Fourteen days after transplantation into RFP transgenic nude mice, the Gelfoam® was removed and re-transplanted into the subcutis on the flank of ND-GFP transgenic nude mice in which nascent blood vessels express GFP. Skin flaps were made and anastomosis between the GFP-expressing nascent blood vessels of ND-GFP transgenic nude mice and RFP blood vessels in the Gelfoam® was imaged 14 and 21 days after re-transplantation. The results presented in this report indicate a possible mechanism for tumor angiogenesis and suggest a new paradigm of therapeutic revascularization of ischemic organs requiring new blood vessels and in other diseases.

Imageable orthothopic metastatic mouse models for the identification of the antitumor and antimetastatic efficacy of traditional Chinese medicine (TCM)

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Background: Traditional Chinese Medicine (TCM) is still poorly understood with regard to the types of cancer it is effective against, as well as its mechanism of action. Modernization of TCM evaluation is necessary in order for TCM to be effectively developed. We report here on the use of patient-like orthotopic nude-mouse models of metastatic cancer to obtain proof-of-concept that TCM combinations can have anti-tumor and anti-metastatic activity. Methods: In the present study, human and mouse lung cancer and pancreatic cancer cell lines (H460, Lewis lung carcinoma [LLC] and MIA-PaCa-2, respectively), labeled with red fluorescent protein (RFP) or green fluorescent protein (GFP) were used. The cells were initially implanted subcutaneously or injected in the tail vein in nude mice. Subcutaneous tumors were harvested to obtain tissue fragments which were implanted orthotopically in nude mice. These models were used to evaluate the anti-tumor and anti-metastatic efficacy of the TCM termed Fufang LQ (LQ), which contains a mixture of Chinese herbs. Results: LQ (gavage, 600 mg/kg/day) significantly inhibited pancreatic and lung cancer tumor growth as measured by imaging, tumor and weight in both subcutaneous and orthotopic models. LQ was significantly efficacious against primary and metastatic cancer in the above models without weight loss in contrast to drugs such as doxorubicin and cisplatin, which caused significant weight loss. Survival of tumor-bearing mice was also prolonged by LQ treatment. Conclusions: The results of the present study indicate that TCM can have non-toxic efficacy, in contrast to standard chemotherapy drugys, against metastatic pancreatic and lung cancer in clinically-relevant orthotopic mouse models of cancer, an important step toward the clinical development of TCM.

The cyan fluorescent protein nude mouse as a host for multicolor-coded imaging models of primary and metastatic tumor microenvironments

The tumor microenvironment (TME) has an important influence on tumor progression. For example, we have discovered that passenger stromal cells are necessary for metastasis. In this report, we describe six different cyan fluorescent protein (CFP) multicolor TME nude mouse models. The six different implantation models were used to image the TME using multiple colors of fluorescent proteins: I) Red fluorescent protein (RFP)- or green fluorescent protein (GFP)-expressing HCT-116 human colon cancer cells were implanted subcutaneously in the CFP-expressing nude mice. CFP stromal elements from the subcutaneous TME were visualized interacting with the RFP- or GFP-expressing tumors. II) RFP-expressing HCT-116 cells were transplanted into the spleen of CFP nude mice, and experimental metastases were then formed in the liver. CFP stromal elements from the liver TME were visualized interacting with the RFP-expressing tumor. III) RFP-expressing HCT-116 cancer cells were transplanted in the tail vein of CFP-expressing nude mice, forming experimental metastases in the lung. CFP stromal elements from the lung were visualized interacting with the RFP-expressing tumor. IV) In order to visualize two different tumors in the TME, GFP-expressing and RFP-expressing HCT-116 cancer cells were co-implanted subcutaneously in CFP-expressing nude mice. A 3-color TME was formed subcutaneously in the CFP mouse, and CFP stromal elements were visualized interacting with the RFP- and GFP-expressing tumors. V) In order to have two different colors of stromal elements, GFP-expressing HCT-116 cells were initially injected subcutaneously in RFP-expressing nude mice. After 14 days, the tumor, which consisted of GFP cancer cells and RFP stromal cells derived from the RFP nude mouse, was harvested and transplanted into the CFP nude mouse. CFP stromal cells invaded the growing transplanted tumor containing GFP cancer cells and RFP stroma. VI) Mouse mammary tumor (MMT) cells expressing GFP in the nucleus and RFP in the cytoplasm were implanted in the spleen of a CFP nude mouse. Cancer cells were imaged in the liver 3 days after cell injection. The dual-color dividing MMT cells and CFP hepatocytes, as well as CFP non-parenchymal cells of the liver were imaged interacting with the 2-color cancer cells. CFP-expressing host cancer-associated fibroblasts (CAFs) were predominantly observed in the TME models developed in the CFP nude mouse. Thus, the CFP nude mouse adds another color to the pallet of the TME, allowing multiple types of color-coded cancer and stromal cells to be imaged simultaneously. The multi-colored models described in this report provide new opportunities to study the cellular interactions in the live primary and metastatic TME.

Abstract 438: The CFP nude mouse as a host for color-coded imaging of the tumor microenvironment

We have developed a color-coded model to study the tumor microenvironment using cancer cells expressing RFP or GFP implanted in nude mice expressing cyan fluorescent protein (CFP). When RFP or GFP HCT-116 were injected subcutaneously in CFP expressing nude mice, CFP expressing cancer-associated fibroblasts migrated to the tumor site. CFP-expressing tumor blood vessels were observed in the tumor. Other CFP host stromal cells were observed throughout the tumor mass. When RFP HCT-116 cells were transplanted in the spleen of CFP nude mice, they formed tumors in the liver. When RFP HCT-116 cancer cells were transplanted in the tail vein of CFP nude mice and they formed tumors in the lung. CFP-expressing host cells were observed in these tumors. When the RFP mouse mammary cancer cell line (RFP MMT) was injected subcutaneously in the CFP nude mouse, numerous CFP-expressing fibroblasts and CFP-expressing blood vessels was observed in the resulting tumor. A large inflammatory population of different CFP-expressing white blood cells surrounded the necrotic area of the tumor suggesting a relationship of these cells to tumor necrosis. GFP and RFP HCT-116 cancer cells were co-injected subcutaneously in CFP-nude mice and tumor growth was followed for 21 days. This three-color model enabled visualization of the tumor mass and its neovasculature in addition to a detailed visualization of other host reactions. GFP HCT-116 cancer cells were initially injected subcutaneously in RFP-nude mice and tumors formed within 14 days. At this point, the tumor mass which consisted of GFP cancer cells and RFP stroma derived from the RFP nude mouse, was harvested and transplanted to a CFP-nude mouse. CFP host cells invaded the growing transplanted tumor containing dual-color cancer cells and RFP stroma. Thus the CFP-nude mouse adds another color to the pallet to study the human tumor microenvironment allowing 4 types of cells to be simultaneously imaged in tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 438. doi:10.1158/1538-7445.AM2011-438

Abstract 579: Chinese herbal mixture LQ inhibits tumor growth and metastasis and increases survival in orthotopic and other mouse models of human and mouse cancer

Natural products have been used as sources of first-line cancer chemotherapeutic agents, including vinca alkaloids, taxanes, podophyllotoxin and camptothecin. However, Traditional Chinese Medicine (TCM) combinations (Fufang), which have been widely used in China for over 5000 years, are still poorly understood with regard to the types of cancer they are effective against as well as their mechanism of action. We report here on the use of patient-like orthotopic nude-mouse models of metastatic cancer and other mouse tumor models to obtain proof-of-concept that TCM (Fufang) combinations have anti-tumor and anti-metastatic activity. In the present study, human and mouse lung, pancreatic and prostate cancer cell lines (H460, Lewis lung carcinoma [LLC) MIA-PaCa-2 and PC-3, respectively), labeled with red fluorescent protein (RFP) or green fluorescent protein (GFP), were orthotopically implanted or injected subcutaneously, or injected in the tail vein in nude mice to evaluate anti-tumor and anti-metastatic efficacy of the Fufang LQ, which contains a mixture of herbs. Results showed that LQ (gavage, 600 mg/kg/day) significantly inhibited prostate, pancreatic and lung cancer tumor growth as measured by imaging, tumor size and weight, in both subcutaneous and metastatic models. LQ was efficacious against primary and metastatic cancer without weight loss in contrast to drugs such as doxorubicin and cisplatin, which caused significant weight loss. Survival of tumor-bearing mice was also prolonged by LQ treatment. Furthermore, in vitro experiments demonstrated that LQ inhibited proliferation of tumor cells (LLC, H460, PC-3 and MIA-PaCa-2) in a dose-dependent manner. Those results indicate that LQ has efficacy against metastatic pancreatic and lung and prostate cancer which demonstrates its clinical potential. The results also suggest that GFP- and RFP-expressing tumors in orthotopic and other nude mouse models can be widely used for in vivo evaluation of TCM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 579.

Development of the transgenic cyan fluorescent protein (CFP)-expressing nude mouse for "Technicolor" cancer imaging

A major goal for in vivo biology is to develop models which can express multiple colors of fluorescent proteins in order to image many processes simultaneously in real time. Towards this goal, the cyan fluorescent protein (CFP) nude mouse was developed by crossing non-transgenic nude mice with the transgenic CK/ECFP mouse in which the beta-actin promoter drives expression of CFP in almost all tissues. In crosses between nu/nu CFP male mice and nu/+ CFP female mice, approximately 50% of the embryos fluoresced blue. In the CFP nude mice, the pancreas and reproductive organs displayed the strongest fluorescent signals of all internal organs which vary in intensity. Orthotopic implantation of XPA-1 human pancreatic cancer cells expressing red fluorescent protein (RFP); or green fluorescent protein (GFP) in the nucleus and RFP in the cytoplasm, was performed in female nude CFP mice. Color-coded fluorescence imaging of these human pancreatic cancer cells implanted into the bright blue fluorescent pancreas of the CFP nude mouse afforded novel insight into the interaction of the pancreatic tumor and the normal pancreas, in particular the strong desmoplastic reaction of the tumor. The naturally enhanced blue fluorescence of the pancreas in the CFP mouse serves as an ideal background for color-coded imaging of the interaction of implanted cancer cells and the host. The CFP nude mouse will provide unique understanding of the critical interplay between the cancer cells and their microenvironment.

The cyan fluorescent protein (CFP) transgenic mouse as a model for imaging pancreatic exocrine cells

CONTEXT

The use of fluorescent proteins for in vivo imaging has opened many new areas of research. Among the important advances in the field have been the development of transgenic mice expressing various fluorescent proteins.

OBJECTIVE

To report whole-body and organ-specific fluorescence imaging to characterize the transgenic cyan fluorescent protein mouse.

DESIGN

Mice were imaged using two devices. Brightfield images were obtained with the OV100 Small Animal Imaging System (Olympus Corp., Tokyo, Japan). Fluorescence imaging was performed under the cyan fluorescent protein filter using the iBox Small Animal Imaging System (UVP, Upland, CA, USA).

INTERVENTION

All animals were sacrificed immediately before imaging. They were imaged before and throughout multiple steps of a complete necropsy. Harvested organs were also imaged with both devices. Selected organs were then frozen and processed for histology, fluorescence microscopy, and H&E staining. Fluorescence microscopy was performed with an Olympus IMT-2 inverted fluorescence microscope.

MAIN OUTCOME MEASURE

Determination of fluorescence intensity of different organs.

RESULTS

Surprisingly, we found that there is differential enhancement of fluorescence among organs; most notably, the pancreas stands out from the rest of the gastrointestinal tract, displaying the strongest fluorescence of all organs in the mouse. Fluorescence microscopy demonstrated that the cyan fluorescent protein fluorescence resided in the acinar cells of the pancreas and not the islet cells.

CONCLUSIONS

The cyan fluorescent protein mouse should lead to a deeper understanding of pancreatic function and pathology, including cancer.

A transgenic red fluorescent protein-expressing nude mouse for color-coded imaging of the tumor microenvironment

The tumor microenvironment (TME) is critical for tumor growth and progression. We have previously developed color-coded imaging of the TME using a green fluorescent protein (GFP) transgenic nude mouse as a host. However, most donor sources of cell types appropriate for study in the TME are from mice expressing GFP. Therefore, a nude mouse expressing red fluorescent protein (RFP) would be an appropriate host for transplantation of GFP-expressing stromal cells as well as double-labeled cancer cells expressing GFP in the nucleus and RFP in the cytoplasm, thereby creating a three-color imaging model of the TME. The RFP nude mouse was obtained by crossing non-transgenic nude mice with the transgenic C57/B6 mouse in which the beta-actin promoter drives RFP (DsRed2) expression in essentially all tissues. In crosses between nu/nu RFP male mice and nu/+ RFP female mice, the embryos fluoresced red. Approximately 50% of the offspring of these mice were RFP nude mice. In the RFP nude mouse, the organs all brightly expressed RFP, including the heart, lungs, spleen, pancreas, esophagus, stomach, duodenum, the male and female reproductive systems; brain and spinal cord; and the circulatory system, including the heart, and major arteries and veins. The skinned skeleton highly expressed RFP. The bone marrow and spleen cells were also RFP positive. GFP-expressing human cancer cell lines, including HCT-116-GFP colon cancer and MDA-MB-435-GFP breast cancer were orthotopically transplanted to the transgenic RFP nude mice. These human tumors grew extensively in the transgenic RFP nude mouse. Dual-color fluorescence imaging enabled visualization of human tumor-host interaction. The RFP nude mouse model should greatly expand our knowledge of the TME.

Nestin-linked green fluorescent protein transgenic nude mouse for imaging human tumor angiogenesis

We report here a novel transgenic nude mouse for the visualization of human tumor angiogenesis. We have recently shown that the neural stem cell marker nestin is expressed in hair follicle stem cells and blood vessel networks in the skin of C57/B6 transgenic mice with nestin regulatory element-driven green fluorescent protein (ND-GFP). Others have shown ND-GFP is expressed in the brain, pancreas, and testes in these mice. In the present study, the nestin ND-GFP gene was crossed into nude mice on the C57/B6 background to obtain ND-GFP nude mice. ND-GFP was expressed in the brain, spinal cord, pancreas, stomach, esophagus, heart, lung, blood vessels of glomeruli, blood vessels of skeletal muscle, testes, hair follicles, and blood vessel network in the skin of ND-GFP nude mice. Human lung cancer, pancreatic cancer, and colon cancer cell lines as well as a murine melanoma cell line and breast cancer tumor cell line expressing red fluorescent protein were implanted orthotopically, and a red fluorescent protein-expressing human fibrosarcoma was implanted s.c. in the ND-GFP nude mice. These tumors grew extensively in the ND-GFP mice. ND-GFP was highly expressed in proliferating endothelial cells and nascent blood vessels in the growing tumors, visualized by dual-color fluorescence imaging. Results of immunohistochemical staining showed that CD31 was expressed in the ND-GFP-expressing nascent blood vessels. The ND-GFP transgenic nude mouse model enables the visualization of nascent angiogenesis in human and mouse tumor progression. These results suggest that this model is useful for the imaging of the angiogenesis of human as well as rodent tumors and visualization of the efficacy of angiogenetic inhibitors.

Transgenic nude mouse with ubiquitous green fluorescent protein expression as a host for human tumors

We report here the development of the transgenic green fluorescent protein (GFP) nude mouse with ubiquitous GFP expression. The GFP nude mouse was obtained by crossing nontransgenic nude mice with the transgenic C57/B6 mouse in which the beta-actin promoter drives GFP expression in essentially all tissues. In crosses between nu/nu GFP male mice and nu/+ GFP female mice, the embryos fluoresced green. Approximately 50% of the offspring of these mice were GFP nude mice. Newborn mice and adult mice fluoresced very bright green and could be detected with a simple blue-light-emitting diode flashlight with a central peak of 470 nm and a bypass emission filter. In the adult mice, the organs all brightly expressed GFP, including the heart, lungs, spleen, pancreas, esophagus, stomach, and duodenum. The following systems were dissected out and shown to have brilliant GFP fluorescence: the entire digestive system from tongue to anus; the male and female reproductive systems; brain and spinal cord; and the circulatory system, including the heart and major arteries and veins. The skinned skeleton highly expressed GFP. Pancreatic islets showed GFP fluorescence. The spleen cells were also GFP positive. Red fluorescent protein (RFP)-expressing human cancer cell lines, including PC-3-RFP prostate cancer, HCT-116-RFP colon cancer, MDA-MB-435-RFP breast cancer, and HT1080-RFP fibrosarcoma were transplanted to the transgenic GFP nude mice. All of these human tumors grew extensively in the transgenic GFP nude mouse. Dual-color fluorescence imaging enabled visualization of human tumor-host interaction by whole-body imaging and at the cellular level in fresh and frozen tissues. The GFP mouse model should greatly expand our knowledge of human tumor-host interaction.

Esophageal papillomatosis complicated by squamous cell carcinoma in situ

We present a case of esophageal papillomatosis with underlying squamous cell carcinoma in situ. An esophageal lesion resected from a 74-year-old woman demonstrated histological findings characteristic of squamous cell papilloma (fibrovascular core and numerous finger-like projections covered with hyperplastic squamous epithelium) and severe dysplasia characteristic of squamous cell carcinoma. The relation of squamous papilloma and squamous cell carcinoma is discussed. It is suggested that esophageal squamous cell papilloma is a premalignant lesion.

The development and validation of Spanish versions of the State and Trait Food Cravings Questionnaires

OBJECTIVE

We developed and tested the psychometric properties of Spanish versions of the Trait and State Food Cravings Questionnaires (FCQ-T and FCQ-S respectively).

METHOD

The instruments were translated and adapted to Spanish and administered to undergraduate students from a Southern university in Spain (N = 271). The data were analyzed using confirmatory factor analysis to compare the factor structure of the English and Spanish versions of both questionnaires.

RESULTS

The factors structure of both questionnaires obtained excellent fit indices across their Spanish versions with the one exception that some factors of the FCQ-S were more highly intercorrelated among the Spanish sample than the American.

DISCUSSION

This study supports the conceptualization of food cravings as universal multidimensional motivational states that can be reliably measured and supports the use of the Spanish versions of the FCQ.

Associative tolerance to nicotine analgesia in the rat: tail-flick and hot-plate tests

Previous assessments of associative nicotine tolerance may have confounded associative effects with novelty-induced stress effects, instrumental learning effects, or both. That is, subjects were tested in novel environments, allowed to practice the test response, or both during the tolerance development phase. In the first study, 32 male Sprague-Dawley rats were injected with various doses of nicotine and tested for nociception in the tail-flick and hot-plate tests to assess nicotine's analgesic effects. In the second study, 35 rats received nicotine explicitly paired or unpaired with a distinctive test context. All animals were equally preexposed to the test environment, and none had the opportunity to practice the test response. Paired rats developed greater nicotine tolerance than unpaired rats. This context-dependent (associative) tolerance effect was found with both tail-flick and hot-plate tests.

Improving health service quality from within: the case of United Leeds Teaching Hospitals NHS Trust

Illustrates how the implementation of the internal customer concept has assisted United Leeds Teaching Hospitals NHS Trust to establish a culture for quality. Explains the conceptual framework on which the notion of the internal customer is derived. Describes how, from 1992 to date, the Trust's quality management approach was designed to apply these management principles in a large teaching hospital setting. Outlines how this quality management approach has been successful in enabling departmental managers to recognize, develop and improve internal customer/supplier relationships. Concludes by explaining that business process re-engineering is now being applied as a prime quality tool to help deliver a major culture change throughout the organization.

CHEMICAL CONSTITUENTS OF CHICOZAPOTE

not available