Factors affecting diabetes knowledge in Type 2 diabetic veterans

AIMS/HYPOTHESIS

To describe the clinical, psychological and social factors affecting diabetes knowledge of veterans with established Type 2 diabetes.

METHODS

We conducted an observational study of 284 insulin-treated veterans with stable Type 2 diabetes. All subjects completed the University of Michigan Diabetes Research and Training Centre Knowledge Test, the Diabetes Care Profile, the Mini-Mental State Examination, the Geriatric Depression Scale, and the Diabetes Family Behaviour Checklist. Stepwise multiple linear regression was used to develop a model for the diabetes knowledge score based upon clinical and psychosocial variables.

RESULTS

One hundred eighty subjects were evaluated in a derivation set. The mean age +/- SD was 65.4+/-9.6 years, 94% were men, and 36% were members of a minority group. Performance on the diabetes knowledge test was poor (64.9+/-15.3% correct). Self-perceived understanding of all management objectives explained only 6% of the variance in the knowledge scores. Multivariate analysis showed that age, years of schooling, duration of treatment, cognitive function, sex, and level of depression were independent determinants of the knowledge score. When the model was applied to 104 subjects in a validation set, there was a strong correlation between observed and predicted scores (r=0.537; p<0.001).

CONCLUSIONS/INTERPRETATION

Stable, insulin-treated veterans have major deficiencies in diabetes knowledge that could impair their ability to provide self-care. A multivariate model comprised of demographic variables and psychosocial profiling can identify patients who have limited diabetes knowledge and be used to assess individual barriers to ongoing diabetes education.

Glucose clearance in grazing mares is affected by diet, pregnancy, and lactation

The glucose tolerance test in the horse may be used to determine metabolic responses to diet, disease, or physiologic state. The objective of this study was to determine the effect of reproductive stage (gestation and lactation) and supplemental dietary energy source (sugar and starch [SS] or fiber and fat [FF]) on glucose metabolism in grazing mares using an oral glucose tolerance test. Twelve mares, six on each supplement, were examined on three occasions: one in the third trimester of pregnancy, the second in early lactation, and the third in late lactation. During each test, venous samples were taken at 30 and 1 min before, and 30, 60, 90, 120, 150, 180, 240, and 300 min after a nasogastric dose of glucose at 0.2 g/kg of BW. Plasma was assayed for glucose, insulin, and cortisol. Statistical analysis was a mixed model with repeated measures with horse, diet, and reproductive stage as fixed effects. The incremental glucose area under the curve (AUC) in response to oral glucose was lower in SS than in FF mares (P = 0.022). Mares tended to have a lower incremental glucose AUC in early lactation than in late gestation (P = 0.057), and insulin AUC was lower in early lactation than in late gestation (P = 0.002) and late lactation (P = 0.013). Glucose clearance was more rapid (P = 0.007) in SS than in FF mares. The glycemic response to the oral glucose tolerance test was consistent with adaptation to dietary sugar and starch as well as metabolic changes associated with pregnancy and lactation. Feeding twice-daily grain meals rich in SS influenced glucose metabolism in horses to an extent that the natural adaptation of glucose metabolism to pregnancy was moderated. Feeding a diet rich in FF more closely mimics the natural grazing state of pasture and allows for adaptation of glucose metabolism to pregnancy and lactation.

Methioninase gene therapy with selenomethionine induces apoptosis in bcl-2-overproducing lung cancer cells

We have previously shown that the toxic pro-oxidant methylselenol is released from selenomethionine (SeMET) by cancer cells transformed with the adenoviral methionine alpha,gamma-lyase (methioninase, MET) gene cloned from Pseudomonas putida. Methylselenol damaged the mitochondria via oxidative stress, and caused cytochrome c release into the cytosol thereby activating caspase enzymes and thereby apoptosis. However, gene therapy strategies are less effective if tumor cells overexpress the antiapoptotic mitochondrial protein bcl-2. In this study, we investigated whether rAdMET/SeMET was effective against bcl-2-overproducing A549 lung cancer cells. We established two clones of the human lung cancer A549 cell line that show moderate and high expression levels of bcl-2, respectively, compared to the parent cell line, which has very low bcl-2 expression. Staurosporine-induced apoptosis was inhibited in the bcl-2-overproducing clones as well as in the parental cell line. In contrast to staurosporine, apoptosis was induced in the bcl-2-overproducing clones as well as the parental cell line by AdMET/SeMET. Apoptosis in the rAdMET-SeMET-treated cells was determined by fragmentation of nuclei, and release of cytochrome c from mitochondria to the cytosol. A strong bystander effect of AdMET/SeMET was observed on A549 cells as well as the bcl-2-overproducing clones. rAdMET/SeMET prodrug gene therapy is therefore a promising novel strategy effective against bcl-2 overexpression, which has blocked other gene therapy strategies.

Combination efficacy of doxorubicin and adenoviral methioninase gene therapy with prodrug selenomethionine

We have previously demonstrated an enzyme activation prodrug gene therapy strategy using the methionine alpha,gamma-lyase gene (MET) cloned from Pseudomonas putida, in combination with selenomethionine (SeMET) as a prodrug. MET gene transfer via a recombinant adenovirus (Ad-MET) converts the physiologic compound SeMET to highly toxic methylselenol. In this study, we have developed a combination therapy approach using Ad-MET/SeMET gene therapy and doxorubicin (DOX). The combination significantly delayed the growth of H460, an aggressively-growing human lung cancer cell line, in nude mice. H460 cells were injected intra-dermally in nude mice. Tumor-bearing mice were divided into 12 groups [Control (Ctrl), DOX, SeMET, SeMET + DOX, Ad-Ctrl, Ad-Ctrl + SeMET, Ad-Ctrl + DOX, Ad-Ctrl + SeMET + DOX, Ad-MET, Ad-MET + DOX, Ad-MET + SeMET, and Ad-MET + SeMET + DOX]. DOX (2 mg/kg body weight) was given intra-peritoneally twice at 7-day intervals. SeMET (1 microM/mouse) was given by intra-tumor injection everyday, starting the following day after transfection with adenovirus. Tumor growth in the untreated group showed a 10-fold increase in tumor volume after two weeks. In contrast, the increase was only 2.5-fold in the DOX + Ad-MET/SeMET group. The treatment with DOX alone at the low-dose used showed no effect compared to the control group. There was a 5.8-fold increase in tumor volume in mice treated with Ad-MET/SeMET gene therapy alone. The tumor doubling-time was increased to approximately 10 days with the combination therapy of Ad-MET + SeMET + DOX as opposed to 2-3 days in all other treatment groups.

Speed associated with plasma pH, oxygen content, total protein and urea in an 80 km race

To test the hypothesis that endurance performance may be related quantitatively to changes in blood, we measured selected blood variables then determined their reference ranges and associations with speed during an 80 km race. The plan had 46 horses in a 2 x 2 factorial design testing a potassium-free electrolyte mix and a vitamin supplement. Blood samples were collected before the race, at 21, 37, 56 and 80 km, and 20 min after finishing, for assay of haematocrit, plasma pH, pO2, pCO2, [Na+], [K+], [Ca++], [Mg++], [Cl-], lactate, glucose, urea, cortisol, alpha-tocopherol, ascorbate, creatine kinase, aspartate amino transferase, lipid hydroperoxides, total protein, albumin and creatinine, and erythrocyte glutathione and glutathione peroxidase. Data from 34 finishers were analysed statistically. Reference ranges for resting and running horses were wide and overlapping and, therefore, limiting with respect to evaluation of individual horses. Speed correlations were most repeatable, with variables reflecting blood oxygen transport (enabling exercise), acidity and electrolytes (limiting exercise) and total protein (enabling then, perhaps, limiting). Stepwise regressions also included plasma urea concentration (limiting). The association of speed with less plasma acidity and urea suggests the potential for fat adaptation and protein restriction in endurance horses, as found previously in Arabians performing repeated sprints. Conditioning horses fed fat-fortified and protein-restricted diets may not only improve performance but also avoid grain-associated disorders.

Disagreement between height/weight classifications of underweight, normal weight, and obesity in peritoneal dialysis patients

Peritoneal dialysis (PD) patients are classified as underweight, normal weight, or obese by height/weight indices including body mass index (BMI) and the body weight/desired weight (W/DW) ratio. We compared these classifications of degree of obesity in 378 women and 555 men on PD. We used these cut-off values: for underweight, BMI < or = 18.5 and W/DW < or = 0.9; for obesity, BMI > or = 30.0 and W/DW > or = 1.2. The W/DW values were calculated assuming first a small frame, then a medium frame, and finally a large frame for all subjects. Regardless of sex or skeletal frame, BMI correlated highly with W/DW (r value between 0.98 and 0.99); however, the range of BMI values corresponding by linear regression to the normal range of W/DW (0.9-1.2) was narrower than the range of "normal" BMI (18.5-30.0). Consequently, regardless of sex or skeletal frame, smaller fractions of the patient population were classified as underweight or obese by BMI standards than by W/DW standards. The degree of agreement of the classifications of subjects as underweight, normal weight, or obese by BMI and W/DW was evaluated by Cohen's kappa ratio. The kappa ratio varied between 0.47 and 0.58, indicating a reasonable--but not high--degree of agreement beyond chance. The highest kappa ratios were obtained assuming a medium skeletal frame for both women and men. Substantial discrepancies are observed in the classification of PD patients as underweight, normal weight, or obese by BMI and W/DW. Further research is needed to identify the height/weight index that has the strongest association both with clinical outcomes and with other, more precise measurements of body fat content.

Acquisition of multidrug resistance in recurrent breast cancer demonstrated by the histoculture drug response assay

Recurrent breast cancer has a very poor response rate to chemotherapy. To understand the degree of acquisition of multidrug resistance in recurrent disease, 24 recurrent breast tumors and 127 primary tumors were evaluated and compared for chemosensitivity in the histoculture drug response assay (HDRA). The evaluation rate was 98.8%. The HDRA utilizes 3-dimensional culture of human tumors on collagen-gel rafts. Doxorubicin (DXR), 5-fluorouracil (5-FU) and mitomycin C (MMC) were tested as standard agents and cisplatin (CDDP) as a candidate agent on surgical specimen of breast cancer in the HDRA. In vitro drug exposure in the HDRA was for 7 days. At the end of the assay, tumor response was assessed by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The mean inhibition rates of primary tumors vs. recurrent tumors were 57.9% and 38.6% for DXR (p<0.0005); 59.9% and 42.8% for MMC (p<0.01); 49.0% and 33.4% for 5-FU (p<0.01); and 34.5% and 16.0% for CDDP (p<0.005), respectively. The recurrent cases were pretreated clinically with CAF (cyclophosphamide, DXR and 5-FU), CEF (cyclophosphamide, epirubicin and 5-FU) or CMF (cyclophosphamide, methotrexate and 5-FU). In the CAF and CEF group, the HDRA sensitivity to CDDP was significantly lower in recurrent disease (p<0.005) than that of primary breast cancer suggesting that one agent can induce resistance to another. This is further suggested by the fact that 64.7% of the recurrent cases were resistant to all 4 agents tested as opposed to 27% of the primary cases and that only 5.9% of the recurrent cases were sensitive to three or more agents as opposed to 18% of the primary cases. The correlation of the HDRA results to clinical outcome in the study was 80.0% with 15 cases evaluated consisting of 5 true positives, 3 false positives, 7 true negatives and no false negatives. Thus, the HDRA gives useful clinical information, in particular for the specific individualized treatment design necessary to overcome the multidrug resistance problem of recurrent breast cancer.

Step-down management of gastroesophageal reflux disease

BACKGROUND & AIMS

As the economic burden of gastroesophageal reflux disease (GERD) is largely weighted to maintenance as opposed to initial therapy, switching from more potent to less expensive medication once symptoms are alleviated (step-down therapy) may prove to be most cost-effective. This study aimed to prospectively evaluate the feasibility of step-down therapy in a cohort of patients with symptoms of uncomplicated GERD.

METHODS

Patients whose GERD symptoms were alleviated by proton pump inhibitors (PPIs) were recruited from outpatient general medicine clinics. After baseline demographic and quality of life information were obtained, PPIs were withdrawn from subjects in a stepwise fashion. Primary outcome was recurrence of symptoms during follow-up that required reinstitution of PPIs. Secondary outcomes included changes in quality of life and overall cost of management. Predictors of nonresponse to step-down were assessed.

RESULTS

Seventy-one of 73 enrolled subjects completed the study. Forty-one of 71 (58%) were asymptomatic off PPI therapy after 1 year of follow-up. Twenty-four of 71 (34%) required histamine 2-receptor antagonists, 5/71 (7%) prokinetic agents, 1/71 (1%) both, and 11/71 (15%) remained asymptomatic without medication. Quality of life did not significantly change, whereas management costs decreased by 37%. Multivariable analysis revealed younger age and a dominant symptom of heartburn to predict PPI requirement.

CONCLUSIONS

Step-down therapy is successful in the majority of patients and can decrease costs without adversely affecting quality of life.

Methioninase cancer gene therapy with selenomethionine as suicide prodrug substrate

In this study, we report a novel approach to gene-directed enzyme prodrug therapy for cancer. This gene therapy strategy exploits the toxic pro-oxidant property of methylselenol, which is released from selenomethionine (SeMET) by cancer cells with the adenoviral-delivered methionine alpha,gamma-lyase (MET) gene cloned from Pseudomonas putida. In MET-transduced tumor cells, the cytotoxicity of SeMET is increased up to 1000-fold compared with nontransduced cells. A strong bystander effect occurred because of methylselenol release from MET gene-transduced cells and uptake by surrounding tumor cells. Methylselenol damaged the mitochondria via oxidative stress and caused cytochrome c release into the cytosol, thereby activating the caspase cascade and apoptosis. Adenoviral MET-gene/SeMET treatment also inhibited tumor growth in rodents and significantly prolonged their survival. Recombinant adenovirus-encoding MET gene-SeMET treatment thereby offers a new paradigm for cancer gene therapy.

Comparison of self-reported initial treatment with medical records: results from the prostate cancer outcomes study

Medical records are generally accepted as the most accurate source of information documenting cancer treatments. However, as the health care system becomes more decentralized and more cancer care is delivered in outpatient settings, it is increasingly difficult and expensive to review records from the many surgeons and medical/radiation oncologists who administer cancer therapies in the community setting. Using 1994-1995 data, the authors compared initial treatment for prostate cancer self-reported (from a mailed questionnaire or telephone/in-person interview) by 3,196 US men in the population-based Prostate Cancer Outcomes Study with information obtained from medical records. Agreement between self-reports and medical records varied by type of treatment. Generally, agreement was excellent for more invasive procedures such as prostatectomy or radiation (kappa values > 0.8), with decreasing agreement for hormone shots and pills (kappa values < 0.7). If the medical record abstract is assumed to be the "gold standard," the estimated sensitivity was generally high (>80%) for prostatectomy and radiation but low (68%) for hormone pills, although the estimated specificity was 90% or greater for all treatments. These results can serve as a useful guide to researchers contemplating the use of surveys as an alternative to medical record abstraction to ascertain treatment in studies of patient outcomes.

Quality-of-life outcomes after primary androgen deprivation therapy: results from the Prostate Cancer Outcomes Study

PURPOSE

To compare health-related quality-of-life outcomes after primary androgen deprivation (AD) therapy with orchiectomy versus luteinizing hormone-releasing hormone (LHRH) agonists for patients with prostate cancer.

PATIENTS AND METHODS

Men (n = 431) newly diagnosed with all stages of prostate cancer from six geographic regions who participated in the Prostate Cancer Outcomes Study and who received primary AD therapy but no other treatments within 12 months of initial diagnosis were included in a study of health outcomes. Comparisons were statistically adjusted for patient sociodemographic and clinical characteristics, timing of therapy, and use of combined androgen blockade.

RESULTS

More than half of the patients receiving primary AD therapy had been initially diagnosed with clinically localized prostate cancer. Among these patients, almost two thirds were at high risk of progression on the basis of prognostic factors. Sexual function outcomes were similar by treatment group both before and after implementation of AD therapy. LHRH patients reported more breast swelling than did orchiectomy patients (24.9% v 9.7%, P <.01). LHRH patients reported more physical discomfort and worry because of cancer or its treatment than did orchiectomy patients. LHRH patients assessed their overall health as fair or poor more frequently than did orchiectomy patients (35.4% v 28.1%, P =.01) and also were less likely to consider themselves free of prostate cancer after treatment.

CONCLUSION

Most endocrine-related health outcomes are similar after surgical versus medical primary hormonal therapy. Stage at diagnosis had little effect on outcomes. These results provide representative information comparing surgical and medical AD therapy that may be used by physicians and patients to inform treatment decisions.

Effect of preventing Staphylococcus aureus carriage on rates of peritoneal catheter-related staphylococcal infections. Literature synthesis

OBJECTIVE

To determine whether specific preventive measures reduce the rate of peritoneal catheter-related infections and peritoneal catheter loss due to Staphylococcus aureus.

DESIGN

Structured literature synthesis.

METHODS

Relevant studies were identified by MEDLINE search, from personal files, and from the reference lists of retrieved articles. We analyzed English-language studies on treatment targeted at S. aureus, with at least 10 subjects and at least 3 months of follow-up, and data on staphylococcal peritoneal dialysis catheter infections. We excluded noncontrolled studies. Two investigators abstracted data using a structured form.

RESULTS

We evaluated six studies with concurrent controls and eight studies with historical controls. In one randomized, placebo-controlled, blinded study, periodic nasal mupirocin ointment reduced the rate of staphylococcal exit-site infection from 0.42 to 0.12 episodes/patient-year (p = 0.006), but had no effect on the rates of staphylococcal tunnel infection, peritonitis, or catheter loss. In one randomized study without placebo control, periodic oral rifampin reduced the rate of staphylococcal exit-site infection from 0.65 to 0.22 epi/pt-yr (p = 0.011), but had no effect on the rate of staphylococcal peritonitis. In another nonblinded, randomized, controlled study, the use of either rifampin or mupirocin was associated with low rates of staphylococcal catheter infections and catheter loss. In one study with historical controls, the rate of staphylococcal exit-site infection and peritonitis was lower after oral rifampin prophylaxis. In seven other studies comparing nasal or exit-site mupirocin to historical controls, the rate of staphylococcal exit-site infection decreased from 0.17 to 0.05 epi/pt-yr, the rate of staphylococcal peritonitis decreased from 0.18 to 0.06 epi/pt-yr, and the rate of catheter loss decreased from 0.09 to 0.05 epi/pt-yr during the mupirocin period.

CONCLUSION

The literature provides strong evidence that staphylococcal carriage prophylaxis using either oral rifampin or mupirocin ointment in the nares or exit site reduces significantly the rate of exit-site infection due to Staphylococcus aureus. Weaker evidence based on studies with historical controls suggests that rifampin or mupirocin prophylaxis also reduces the rate of staphylococcal peritonitis and peritoneal catheter loss. Studies with a stronger level of evidence are needed to verify this last point.

Spatial-temporal imaging of bacterial infection and antibiotic response in intact animals

We describe imaging the luminance of green fluorescent protein (GFP)-expressing bacteria from outside intact infected animals. This simple, nonintrusive technique can show in great detail the spatial-temporal behavior of the infectious process. The bacteria, expressing the GFP, are sufficiently bright as to be clearly visible from outside the infected animal and recorded with simple equipment. Introduced bacteria were observed in several mouse organs including the peritoneal cavity, stomach, small intestine, and colon. Instantaneous real-time images of the infectious process were acquired by using a color charge-coupled device video camera by simply illuminating mice at 490 nm. Most techniques for imaging the interior of intact animals may require the administration of exogenous substrates, anesthesia, or contrasting substances and require very long data collection times. In contrast, the whole-body fluorescence imaging described here is fast and requires no extraneous agents. The progress of Escherichia coli-GFP through the mouse gastrointestinal tract after gavage was followed in real-time by whole-body imaging. Bacteria, seen first in the stomach, migrated into the small intestine and subsequently into the colon, an observation confirmed by intravital direct imaging. An i.p. infection was established by i.p. injection of E. coli-GFP. The development of infection over 6 h and its regression after kanamycin treatment were visualized by whole-body imaging. This imaging technology affords a powerful approach to visualizing the infection process, determining the tissue specificity of infection, and the spatial migration of the infectious agents.

Chronologically-specific metastatic targeting of human pancreatic tumors in orthotopic models

Pancreatic cancer is a highly metastatic disease that responds poorly to currently-available treatment. In order to better visualize and understand the chronology and specificity of metastatic targeting of pancreatic cancer, two human pancreatic cancer cell lines, expressing green fluorescent protein (GFP), were studied in orthotopic models. MIA-PaCa2-GFP and BxPC-3-GFP tumor fragments were transplanted by surgical orthotopic implantation (SOI) to the nude mouse pancreas for fluorescence visualization of the chronology of pancreatic tumor growth and metastatic targeting. BxPC-3-GFP tumors developed rapidly in the pancreas and spread regionally to the spleen and retroperitoneum as early as six weeks. Distant metastases in BxPC-3-GFP were rare. In contrast, MIA-PaCa-2-GFP grew more slowly in the pancreas but rapidly metastasized to distant sites including liver and portal lymph nodes. Regional metastases in MIA-PaCa-2-GFP were rare. These studies demonstrate that pancreatic cancers have highly specific and individual 'seed-soil' interactions governing the chronology and sites of metastatic targeting.

Synergy between methionine stress and chemotherapy in the treatment of brain tumor xenografts in athymic mice

This study describes a novel approach to the treatment of brain tumors with the combination of recombinant L-methionine-alpha-deamino-gamma-lyase and chemotherapeutic regimens that are currently used against such tumors. The growth of Daoy, SWB77, and D-54 xenografts in athymic mice was arrested after the depletion of mouse plasma methionine (MET) with a combination of a MET- and choline-free diet and recombinant L-methionine-alpha-deamino-gamma-lyase. The treated tumor-bearing mice were rescued from the toxic effects of MET withdrawal with daily i.p. homocystine. This regimen suppressed plasma MET to levels below 5 microM for several days, with no treatment-related deaths. MET depletion for 10-12 days induced mitotic and cell cycle arrest, apoptotic death, and widespread necrosis in tumors but did not prevent tumor regrowth after cessation of the regimen. However, when a single dose of 35 mg/m(2) of N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU), which was otherwise ineffective as a single therapy in any of the tumors tested, was given at the end of the MET depletion regimen, a more than 80-day growth delay was observed for Daoy and D-54, whereas the growth of SWB77 was delayed by 20 days. MET-depleting regimens also trebled the efficacy of temozolomide (TMZ) against SWB77 when TMZ was given to animals as a single dose of 180 mg/m(2) at the end of a 10-day period of MET depletion. The enhanced responses of both Daoy and SWB77 to DNA alkylating agents such as BCNU and TMZ could be attributed to the down-regulation of O(6)-methylguanine-DNA methyltransferase activity. However, the synergy of MET depletion and BCNU observed with D-54 tumors, which do not express measurable O(6)-methylguanine-DNA methyltransferase protein, is probably mediated by a different mechanism. MET depletion specifically sensitizes tumors to alkylating agents and does not significantly lower the toxicity of either BCNU or TMZ for the host. In this regard, the combination approach of MET depletion and genotoxic chemotherapy demonstrates significant promise for clinical evaluation.

CT features of pulmonary alveolar proteinosis

OBJECTIVE

This investigation describes the CT features of pulmonary alveolar proteinosis in a large group of patients.

MATERIALS AND METHODS

A retrospective review of 139 chest CT scans (79 thick-section scans and 60 thin-section scans) from 27 patients with pathologically proven pulmonary alveolar proteinosis was performed. Two independent observers assessed the intraslice patterns and zonal distribution of disease on three CT images of each lung. The observers also graded the percentage of ground-glass opacities, air-space opacities, fibrosis, interlobular opacities, intralobular opacities, and emphysema in each slice. CT scans obtained before and after lavage related to 12 whole-lung lavage treatments on nine patients were evaluated.

RESULTS

The dominant intraslice pattern was geographic, but a diffuse pattern was sometimes seen. The most common zonal pattern was uniform; a lower zone predominance was next most frequent. Ground-glass, air-space, and fibrotic opacities had a generally homogeneous craniocaudal distribution, but there was a trend toward more interlobular opacities at the lung bases (p < 0.002). Ground-glass opacities were seen on at least one scan in 100% of the patients. Interlobular opacities (85%), air-space opacities (78%), substantial fibrosis (7%), and intralobular opacities (7%) occurred less frequently. Compared with thick-section images, thin-section images showed more interlobular opacities, but no difference in ground-glass, air-space, or fibrotic disease. The proportion of lung affected by ground-glass and interlobular opacities decreased significantly (p < 0.05) after lavage.

CONCLUSION

Pulmonary alveolar proteinosis does not present only with alveolar disease. The CT appearance typically combines different types of opacities with a geographic pattern and a uniform zonal distribution with variation over time.

Visualization of GFP-Expressing Tumors and Metastasis In Vivo

We have developed mouse models of metastatic cancer with genetically fluorescent tumors that can be imaged in fresh tissue, in situ, as well as externally. To achieve this capability, we have transduced the green fluorescent protein (GFP) gene, cloned from the bioluminescent jellyfish Aequorea victoria, into a series of human and rodent cancer cell lines that were selected in vitro to stably express GFP in vivo after transplantation to metastatic rodent models. Techniques were also developed for transduction of tumors by GFP in vivo. With this fluorescent tool, we detected and visualized for the first time tumors and metastasis in fresh viable tissue or in situ in host organs down to the single-cell level. GFP tumors on the colon, prostate, breast, brain, liver, lymph nodes, lung, pancreas, bone, and other organs can also be visualized externally, transcutaneously by quantitative whole-body fluorescence optical imaging. Real-time tumor and metastatic growth and angiogenesis and inhibition by representative drugs can be imaged and quantified for rapid antitumor, antimetastatic, and antiangiogenesis drug screening. The GFP-transfected tumor cells enabled a fundamental advance in the visualization of tumor growth and metastasis in real time in vivo.

Health outcomes after external-beam radiation therapy for clinically localized prostate cancer: results from the Prostate Cancer Outcomes Study

PURPOSE

Studies reporting effects of radiotherapy for prostate cancer on sexual, bowel, and urinary function have been conducted primarily in referral centers or academic institutions. Effects of external-beam radiotherapy for prostate cancer among a population-based cohort were assessed.

PATIENTS AND METHODS

The study population included 497 white, Hispanic, and African-American men with localized prostate cancer from six US cancer registries who were diagnosed between October 1, 1994, and October 31, 1995, and treated initially with external-beam radiotherapy. They were interviewed at regular intervals, and medical records were reviewed. Distributions of responses for bowel-, urinary-, and sexual-related functions at 6, 12, and 24 months after diagnosis and adjusted mean composite change scores for each domain were analyzed.

RESULTS

Declines of 28.9% in the sexual function score and 5.4% in the bowel function score occurred by 24 months, whereas at this time, the urinary function score was relatively unchanged. A total of 43% of those who were potent before diagnosis became impotent after 24 months. More than two thirds of the men were satisfied with their treatment and would make the same decision again.

CONCLUSION

Sexual function was the most adversely affected quality-of-life domain, with problems continuing to increase between 12 and 24 months. Bowel function problems increased at 6 months, with partial resolution observed by 24 months. Despite the side effects, satisfaction with therapy was high. These results are representative of men in community practice settings and may be of assistance to men and to clinicians when making treatment decisions.

Cytotoxic synergism of methioninase in combination with 5-fluorouracil and folinic acid

Potentiation of the cytotoxic activity of 5-fluorouracil (FUra) by folinic acid (5-HCO-H4folate) is due to elevation of the methylene tetrahydrofolate (CH2-H4folate) level, which increases the stability of the ternary complex of thymidylate synthase (TS), fluorodeoxyuridine monophosphate, and CH2-H4folate that inactivates the TS. Methionine deprivation results in the production of tetrahydrofolate (H4folate) and, subsequently, CH2-H4folate from methyl tetrahydrofolate, as a consequence of the induction of methionine synthesis. We hypothesized that the efficacy of FUra could be augmented by the combination of high-concentration 5-HCO-H4folate and recombinant methioninase (rMETase), a methionine-cleaving enzyme. Studies in vitro were performed with the cell line CCRF-CEM. Cytotoxic synergism of FUra + rMETase and FUra + 5-HCO-H4folate + rMETase was demonstrated with the combination index throughout a broad concentration range of FUra and rMETase. A subcytotoxic concentration of rMETase reduced the IC50 of FUra by a factor of 3.6, and by a factor of 7.5, in the absence and in the presence of 5-HCO-H4folate, respectively. 5-HCO-H4folate increased the intracellular concentrations of CH2-H4folate and H4folate from their baseline levels. Concentrations of folates were not changed by exposure to rMETase. Levels of free TS in cells treated with FUra + 5-HCO-H4folate and with FUra + rMETase were lower than those in cells exposed to FUra alone. The decrease of TS was still more pronounced in cells treated with FUra + 5-HCO-H4folate + rMETase. The synergism described in this study will be a basis for further exploration of combinations of fluoropyrimidines, folates, and rMETase.

Racial and ethnic differences in advanced-stage prostate cancer: the Prostate Cancer Outcomes Study

BACKGROUND

African-Americans have twice the risk of non-Hispanic whites for presenting with advanced-stage prostate cancer. To investigate the reasons for this difference, we evaluated the association between race/ethnicity and advanced-stage prostate cancer, adjusting for demographic, socioeconomic, clinical, and pathologic factors.

METHODS

A population-based cohort of 3173 men diagnosed with prostate cancer between October 1, 1994, and October 31, 1995, was analyzed. Medical record abstracts and self-administered survey questionnaires were used to obtain information regarding race/ethnicity, age, marital status, insurance status, educational level, household income, employment status, comorbidity, urinary function, prostate-specific antigen level, tumor grade, and clinical stage. The odds ratio (OR) for advanced-stage prostate cancer was estimated with weighted logistic regression analysis. All P: values were two-sided.

RESULTS

Clinically advanced-stage prostate cancers were detected more frequently in African-Americans (12.3%) and Hispanics (10.5%) than in non-Hispanic whites (6.3%). Socioeconomic, clinical, and pathologic factors each accounted for about 15% of the increased relative risk. After adjusting for all covariates, the risk remained statistically significantly increased for African-Americans (OR = 2.26; 95% confidence interval [CI] = 1.43 to 3.58) but not for Hispanics (OR = 1.23; 95% CI = 0.73 to 2.08).

CONCLUSION

Traditional socioeconomic, clinical, and pathologic factors accounted for the increased relative risk for presenting with advanced-stage prostate cancer in Hispanic but not in African-American men.

A highly metastatic Lewis lung carcinoma orthotopic green fluorescent protein model

The Lewis lung carcinoma has been widely used for many important studies. However, the subcutaneous transplant or orthotopic cell-suspension injection models have not allowed the expression of its full metastatic potential. A powerful new highly metastatic model of the widely-used Lewis lung carcinoma is reported here using surgical orthotopic implantation (SOI) of tumor fragments and enhanced green fluorescent protein (GFP) transduction of the tumor cells. To achieve this goal, we first developed in vitro a stable high-expression GFP transductant of the Lewis lung carcinoma with the pLEIN retroviral expression vector containing the enhanced Aequorea victoria GFP gene. Stable high-level expression of GFP was found maintained in vivo in subcutaneously-growing Lewis lung tumors. The in vivo GFP-expressing tumors were harvested and implanted as tissue fragments by SOI in the right lung of additional nude mice. This model resulted in rapid orthotopic growth and extensive metastasis visualized by GFP-expression. 100% of the animals had metastases on the ipsilateral diaphragmatic surface, contralateral diaphragmatic surface, contralateral lung parenchima, and in mediastinal lymph nodes. Heart metastases were visualized in 40%, and brain metastases were visualized in 30% of the SOI animals. Mice developed signs of respiratory distress between 10-15 days post-tumor implantation and were sacrificed. The use of GFP-transduced Lewis lung carcinoma transplanted by SOI reveals for the first time the high malignancy of this tumor and provides an important useful model for metastasis, angiogenesis and therapeutic studies.

Transduction of liver cells by lentiviral vectors: analysis in living animals by fluorescence imaging

Viral vectors based on lentiviruses, such as the human immunodeficiency virus, are able to transduce a broad spectrum of nondividing cells in vivo. This ability of lentiviral vectors makes them an attractive vehicle for gene transfer into the liver. In order to determine the requirements for efficient lentiviral gene transfer, we used a fluorescence imaging system, which allows the detection of cells and tissues that express fluorescent reporter genes (e.g., green fluorescence protein) in the living animal. We show that the latest generation of lentiviral vectors efficiently transduces the murine liver. Further analysis demonstrated that neither cell-cycle activation nor division of liver cells is a prerequisite for lentiviral gene transfer in vivo.

Whole-body and intravital optical imaging of angiogenesis in orthotopically implanted tumors

The development of drugs for the control of tumor angiogenesis requires a simple, accurate, and economical assay for tumor-induced vascularization. We have adapted the orthotopic implantation model to angiogenesis measurement by using human tumors labeled with Aequorea victoria green fluorescent protein for grafting into nude mice. The nonluminous induced capillaries are clearly visible against the very bright tumor fluorescence examined either intravitally or by whole-body luminance in real time. The orthotopic implantation model of human cancer has been well characterized, and fluorescence shadowing replaces the laborious histological techniques for determining blood vessel density. Intravital images of orthotopically implanted human pancreatic tumors clearly show angiogenic capillaries at both primary and metastatic sites. A quantitative time course of angiogenesis was determined for an orthotopically growing human prostate tumor periodically imaged intravitally in a single nude mouse over a 19-day period. Whole-body optical imaging of tumor angiogenesis was demonstrated by injecting fluorescent Lewis lung carcinoma cells into the s.c. site of the footpad of nude mice. The footpad is relatively transparent, with comparatively few resident blood vessels, allowing quantitative imaging of tumor angiogenesis in the intact animal. Capillary density increased linearly over a 10-day period as determined by whole-body imaging. Similarly, the green fluorescent protein-expressing human breast tumor MDA-MB-435 was orthotopically transplanted to the mouse fat pad, where whole-body optical imaging showed that blood vessel density increased linearly over a 20-week period. These powerful and clinically relevant angiogenesis mouse models can be used for real-time in vivo evaluation of agents inhibiting or promoting tumor angiogenesis in physiological microenvironments.