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This study evaluated a training program to train lay health volunteers in facilitating smoking cessation for a low-income, African American community in a Midwest city. Fourteen volunteers completed this training. The four-hour training program applied the constructs of the Social Cognitive Theory (SCT), namely self-efficacy and outcome expectations relating to the processes of behavioral change. A repeated measures design was utilized measuring participants 'perceived knowledge, outcome expectations, their self-efficacy on conducting smoking cessation classes and their behavioral change in organizing and conducting smoking cessation programs. Results highlighted statistically significant changes in knowledge, outcome expectations, and self-efficacy (p <0. 05) between pre-test and post-test indicating a successful training program. However, no significance was noted for a change in behavior. Implementation and environmental issues need to be encouraged in future programs in order to effect the behavioral change and continue the success of the program. [ABSTRACT FROM AUTHOR]

Background: There have been sporadic reports on perioperative mortality associated with total knee arthroplasty. The purpose of this study was to determine risk factors for such mortality.Methods: A computer-assisted review of the records of 22,540 consecutive patients who had undergone total knee arthroplasty between 1969 and 1997 was performed to identify all patients who had died within thirty days after the procedure. A detailed analysis of the medical, surgical, anesthetic, and pathological records of the patients was performed, and the mortality was determined according to age, gender, diagnosis, and fixation method.Results: The rate of mortality within thirty days after the operation was 0.21% (forty-seven of 22,540). All deaths occurred in the group of 18,810 patients who had received a cemented implant, and no deaths occurred among the 3730 patients who had received an uncemented implant (p < 0.0001). The mortality rate was 0.24% (forty-three of 18,165) after primary arthroplasty and 0.09% (four of 4375) after revision arthroplasty (p < 0.0003). Three patients (0.01%) died during the operation. Forty-three of the forty-seven patients who died had a history of preexisting cardiovascular and/or pulmonary disease. Simultaneous bilateral total knee arthroplasty was associated with a significantly higher rate of perioperative mortality (p < 0.002).Conclusions: Factors that were associated with a significantly increased mortality after total knee arthroplasty included an age of more than seventy years, primary (as compared with revision) knee surgery, use of a cemented prosthesis, preexisting cardiopulmonary disease, and simultaneous bilateral arthroplasty. [ABSTRACT FROM AUTHOR]

Objectives: Safety and welfare are critical as pandemic-related demands on the healthcare workforce continue. Access to personal protective equipment (PPE) has been a central concern of healthcare workers throughout the COVID-19 pandemic. Against the backdrop of an already strained healthcare system, our study aimed to explore the experiences of healthcare workers with PPE during the first COVID-19 surge (February-June 2020) in Aotearoa/New Zealand (NZ). We also aimed to use these findings to present a strengths-based framework for supporting healthcare workers moving forward., Design: Web-based, anonymous survey including qualitative open-text questions. Questions were both closed and open text, and recruitment was multimodal. We undertook inductive thematic analysis of the dataset as a whole to explore prominent values related to healthcare workers' experiences., Setting: October-November 2020 in New Zealand., Participants: 1411 healthcare workers who used PPE during surge one of the COVID-19 pandemic., Results: We identified four interactive values as central to healthcare workers' experiences: transparency, trust, safety and respect. When healthcare workers cited positive experiences, trust and safety were perceived as present, with a sense of inclusion in the process of stock allocation and effective communication with managers. When trust was low, with concerns over personal safety, poor communication and lack of transparency resulted in perceived lack of respect and distress among respondents. Our proposed framework presents key recommendations to support the health workforce in terms of communication relating to PPE supply and distribution built on those four values., Conclusions: Healthcare worker experiences with PPE access has been likened to 'the canary in the coalmine' for existing health system challenges that have been exacerbated during the COVID-19 pandemic. The four key values identified could be used to improve healthcare worker experience in the future., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

There have been widespread issues with the supply and distribution of personal protective equipment (PPE) globally throughout the COVID-19 pandemic, raising considerable public concern. We aimed to understand the experiences of healthcare workers using PPE during the first COVID-19 surge (February-June 2020) in Aotearoa/New Zealand (NZ). This study consisted of an online, voluntary, and anonymous survey, distributed nationwide via multimodal recruitment. Reported domains included PPE supply, sourcing and procurement, fit-testing and fit-checking, perceived protection, trust and confidence in the workplace, mental health, and the likelihood of remaining in the profession. Differences according to demographic variables (e.g., profession and workplace) were examined. We undertook a descriptive analysis of responses to open-text questions to provide explanation and context to the quantitative data. The survey was completed in October-November 2020 by 1411 healthcare workers. Reported PPE shortages were common (26.8%) among healthcare workers during surge one in NZ. This led to respondents personally saving both new (31.2%) and used (25.2%) PPE, purchasing their own PPE (28.2%), and engaging in extended wear practices. More respondents in the public system reported being told not to wear PPE by their organisation compared with respondents in the private sector. Relatively low numbers of respondents who were required to undertake aerosol-generating procedures reported being fit-tested annually (3.8%), a legal requirement in NZ. Healthcare workers in NZ reported a concerning level of unsafe PPE practices during surge one, as well as a high prevalence of reported mental health concerns. As NZ and other countries transition from COVID-19 elimination to suppression strategies, healthcare worker safety should be paramount, with clear communication regarding PPE use and supply being a key priority.

Aim: Expert recommendations for child/adolescent obesity include extensive investigation for weight-related comorbidities, based on body mass index (BMI) percentile cut-offs. This study aimed to estimate the cost of initial investigations for weight-related comorbidities in children/adolescents with obesity, according to international expert guidelines., Methods: The annual mean cost of investigations for weight-related comorbidities in children/adolescents was calculated from a health-funder perspective using 2019 cost data obtained from three New Zealand District Health Boards. Prevalence data for child/adolescent obesity (aged 2-14 years) were obtained from the New Zealand Health Survey (2017/2018), and prevalence of weight-related comorbidities requiring further investigation were obtained from a previous New Zealand study of a cohort of children with obesity., Results: The cost of initial laboratory screening for weight-related comorbidities per child was NZD 28.36. Based on national prevalence data from 2018/2019 for children with BMI greater than the 98th percentile (obesity cut-off), the total annual cost for initial laboratory screening for weight-related comorbidities in children/adolescents aged 2-14 years with obesity was estimated at NZD 2,665,840. The cost of further investigation in the presence of risk factors was estimated at NZD 2,972,934., Conclusions: Investigating weight-related comorbidities in New Zealand according to international expert guidelines is resource-intensive. Ways to further determine who warrants investigation with an individualised approach are required., (© 2021 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).)

Background: Total hip and knee arthroplasties (THA/TKA) are clinically effective but high cost procedures. The aim of this study is to perform a cost-effectiveness analysis of THA and TKA in the New Zealand (NZ) healthcare system., Methods: Data were collected from 713 patients undergoing THA and 520 patients undergoing TKA at our local public hospital. SF-6D utility values were obtained from participants preoperatively and 1-year postoperatively, and deaths and any revision surgeries from patient records and the New Zealand Joint Registry at minimum 8-year follow-up. A continuous-time state-transition simulation model was used to estimate costs and health gains to 15 years. Quality-adjusted life years (QALYs), treatment costs, and incremental cost-effectiveness ratios (ICERs) were calculated to determine cost effectiveness. ICERs below NZ gross domestic product (GDP; NZ$60 600) and 0.5 times GDP per capita were considered "cost effective" and "highly cost effective" respectively., Results: Cumulative health gains were 2.8 QALYs (THA) and 2.3 QALYs (TKA) over 15 years. Cost effectiveness improved from ICERs of NZ$74,400 (THA) and NZ$93,000 (TKA) at 1 year to NZ$6000 (THA) and NZ$7500 (TKA) at 15 years. THA and TKA were cost effective after 2 years and highly cost effective after 3 years. QALY gains and cost effectiveness were greater in patients with worse preoperative functional status and younger age., Conclusion: THA and TKA are highly cost-effective procedures over longer term horizons. Although preoperative status and age were associated with cost effectiveness, both THA and TKA remained cost effective in patients with less severe preoperative scores and older ages., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The 2020 Census provides the opportunity to reflect on the key role statisticians, demographers, and other social scientists play in safeguarding American democracy. Democracy requires numbers for its proper functioning, and there is now a large statistical infrastructure of which the constitutionally mandated census is the keystone. Mistrust of the government is a major obstacle for the census, potentially affecting both accuracy and completeness. The mistrust is stimulated by fears of individual or household census data being willingly or inadvertently shared with other government agencies (data privacy issues) or even foreign actors (hacking). As two 2019 Supreme Court decisions in juxtaposition suggest, no checks or balances protect the integrity of the census. The professional integrity of statisticians is the best defense of the census.

Abdominal pain is a common reason for medical visits. We examined the prevalence, gastrointestinal, and emotional significance of abdominal pain in a population-based cohort serially followed up from birth to 17 years. Children and adolescents from Generation 2 of the Raine Study participated in comprehensive cross-sectional assessments at ages 2, 5, 8, 10, 14 and 17 years. At 17 years, medical history, general health, gastrointestinal symptoms, medications, health practitioner attendance, and self-rated unhappiness were recorded. Longitudinal data regarding abdominal pain or unhappiness, from serial questionnaires, were analysed to identify factors associated with abdominal pain and adverse emotional health at age 17 years. Females experienced more abdominal pain than males at all ages (p < 0.05). Seventeen-year-old adolescents with abdominal pain reported a higher prevalence of depression, anxiety, being bullied at school, and poorer health status than those without abdominal pain (p < 0.05 for all). Abdominal pain and unhappiness during childhood and mid-adolescence were prospectively associated with recurrent abdominal pain, anxiety, depression and unhappiness during late adolescence (p < 0.05 for all). In conclusion, abdominal pain in children and adolescents associates with depression, anxiety, being bullied, unhappiness and reduced overall health-rating during adolescence. Awareness of these factors may guide management decisions.

Aim: To estimate the cost of diabetes-related hospital admissions to the Southern District Health Board for the year 2016/17., Methods: Unidentified data with an ICD-10-AM diagnostic code for any type of diabetes were obtained for admissions to Dunedin and Southland Hospitals. Each admission was categorised according to whether the diabetes diagnostic code was listed first, second or subsequently, and by diagnostic group within each of these three categories. The case weight for each admission was multiplied by the 2016/17 cost weight value of NZ$4,824.67., Results: There were 6,994 separate hospital admission events. The total cost was NZ$40,986,618. Admissions where diabetes was the primary, secondary or subsequent diagnosis cost NZ$2,214,172, NZ$8,057,235 and NZ$30,697,210, respectively. More than 80% of admissions were for those aged 55 years and over. Ketoacidosis was the most common primary reason for admission (n=103) among those with type 1 diabetes, costing NZ$349,892. When diabetes was not the primary or secondary diagnosis, the most common primary diagnosis was a circulatory system disease, costing NZ$8,181,324. The mean (SD) cost per admission where the primary diagnosis was coronary artery disease with and without diabetes diagnostic codes was NZ$10,407 ($20,694) and NZ$8,657 ($11,347), respectively., Conclusions: The annual cost of diabetes-related hospital admissions is substantial. Monitoring the cost of diabetes to DHBs should be prioritised, along with implementation of interventions that reduce preventable diabetes-related hospital admissions, and new diabetes cases., Competing Interests: SD and KC report grants from New Zealand Society for the Study of Diabetes during the conduct of the study.

Objective: To determine whether Whānau Pakari, a home-based, 12-month multi-disciplinary child obesity intervention programme was cost-effective when compared with the prior conventional hospital-based model of care., Methods: Whānau Pakari trial participants were recruited January 2012-August 2014, and randomised to either a high-intensity intervention (weekly sessions for 12 months with home-based assessments and advice, n=100) or low-intensity control (home-based assessments and advice only, n=99). Trial participants were aged 5-16 years, resided in Taranaki, Aotearoa/New Zealand (NZ), with a body mass index (BMI) ≥98th centile or BMI >91st centile with weight-related comorbidities. Conventional group participants (receiving paediatrician assessment with dietitian input and physical activity/nutrition support, n=44) were aged 4-15 years, and resided in the same or another NZ centre. The change in BMI standard deviation score (SDS) at 12 months from baseline and programme intervention costs, both at the participant level, were used for the economic evaluation. A limited health funder perspective with costs in 2016 NZ$ was taken., Results: The per child 12-month Whānau Pakari programme costs were significantly lower than in the conventional group. In the low-intensity group, costs were NZ$939 (95% CI: 872, 1007) (US$648) lower than the conventional group. In the high-intensity intervention group, costs were NZ$155 (95% CI: 89, 219) (US$107) lower than in the conventional group. BMI SDS reductions were similar in the three groups., Conclusions: A home-based, multi-disciplinary child obesity intervention had lower programme costs per child, greater reach, with similar BMI SDS outcomes at 12 months when compared with the previous hospital-based conventional model., (Copyright © 2018 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.)

Objectives: Although obesity is a major risk factor for nonalcoholic fatty liver (NAFL), not all individuals with obesity develop the condition, suggesting that other factors such as diet may also contribute to NAFL development. We evaluated associations between fructose and total sugar intake and subsequent diagnosis of NAFL in adolescents with obesity and without obesity in a population-based cohort., Methods: Adolescents participating in the Western Australian Pregnancy Cohort (Raine) Study completed 3-day food records and body mass index measurement at age 14 years. At age 17 years, participants underwent abdominal ultrasound to determine NAFL status. Multivariable logistic regression models were used to analyse associations between energy-adjusted fructose and total sugar intake and NAFL status. Food diaries and liver assessments were completed for 592 adolescents., Results: The prevalence of NAFL at age 17 was 12.8% for the total group and 50% for adolescents with obesity. Fructose intake did not significantly differ between adolescents with or without NAFL in our cohort as a whole. Among adolescents with obesity, those without NAFL had significantly lower energy-adjusted fructose intake at age 14 years compared with those with NAFL (mean ± standard deviation [SD] 38.8 ± 19.8 g/day, vs 55.7 ± 14.4 g/day, P = 0.02). Energy-adjusted fructose intake was independently associated with NAFL in adolescents with obesity (OR [odds ratio] 1.09, 95% CI 1.01-1.19, P = 0.03) after the adjustment for confounding factors. Energy-adjusted total sugar intake showed less significance (OR 1.03, 95% CI 0.999-1.07, P = 0.06). No significant associations were observed in other body mass index categories., Conclusions: Lower fructose consumption in adolescents with obesity at 14 years is associated with a decreased risk of NAFL at 17 years. Fructose rather than overall sugar intake may be more physiologically relevant in this association.

The goal of the present study was to determine the minimum concentration of systemic erythropoietin-R76E required for neuroprotection in the retina. Erythropoietin (EPO) exhibits neuroprotective effects in both in vitro and in vivo models of neuronal cell death although its classical function is the regulation of red blood cell production. It can cross the blood brain barrier and therefore can be delivered systemically to affect the retina. However, long-term treatment with exogenous erythropoietin causes polycythemia. To decrease this potentially lethal effect, we generated and tested a modified form that contains a single arginine to glutamate mutation at the 76th position (EPO-R76E). In previous studies, this mutant protected retinal neurons in mouse models of retinal degeneration and glaucoma with similar efficacy as wild-type EPO. However, EPO-R76E has attenuated erythropoietic activity, therefore, neuroprotection can be achieved without causing a significant rise in hematocrit. BALB/cByJ mice received a single intramuscular injection of recombinant adeno-associated virus carrying enhanced green fluorescent protein, Epo, or Epo-R76E. To result in continuous production of four different doses of EPO-R76E, two doses of two different serotypes (2/5 and 2/8) were used. Mice were subjected to optic nerve crush and analysis was performed thirty days later. EPO-R76E showed dose-dependent protection of the retinal ganglion cell bodies, but was unable to prevent axonal degeneration. Furthermore, EPO-R76E induced a dose-dependent rise in the hematocrit that was still attenuated as compared to wild-type EPO., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

A slow progressive death of neurons is the hallmark of neurodegenerative diseases, such as glaucoma. A therapeutic candidate, erythropoietin (EPO), has shown promise in many models of these diseases; however, it also causes polycythemia, a potentially lethal side effect. We have developed a novel mutant form of EPO that is neuroprotective but no longer erythropoietic by altering a single amino acid (arginine to glutamate at position 76; R76E). We hypothesized that a single intramuscular injection of recombinant adeno-associated virus carrying EpoR76E (rAAV2/5.CMV.EpoR76E) would protect retinal ganglion cells in a mouse model of glaucoma without inducing polycythemia. This systemic treatment not only protected the retinal ganglion cell somata located within the retina; it also preserved axonal projections within the optic nerve, while maintaining the hematocrit within normal limits. The rescued retinal ganglion cells retained their visual function demonstrated by flash visual evoked potentials. To our knowledge, this is the first demonstration of a therapy that protects neurons from death and prevents loss of visual function from the slow neurodegenerative effects of glaucoma. Because of its broad range of cellular targets, EpoR76E is likely to be successful in treating other neurodegenerative diseases as well.

Hepatic failure is a significant medical problem which has been unsuccessfully treated by hemodialysis. However, similar therapies using recirculated dialysate regenerated by sorbents in place of single-pass dialysate have been beneficial in treating acute-on-chronic liver failure. The advantages of sorbent-based treatments include some selectivity of toxin removal and improved removal of protein-bound toxins. Activated carbon has been extensively used in detoxification systems, but has often had insufficient toxin capacity. Powdered activated carbon, because of its large surface area, can provide greater binding capacity for bilirubin and other toxins than granular carbon commonly used in detoxifying columns. Methods of using powdered carbon in extracorporeal blood treatment devices are reviewed in the present paper, including liver dialysis and a new sorbent suspension reactor (SSR); and the abilities and limitations of the SSR and columns to process protein solutions are discussed.

In 1996, a coalition of diverse and determined organizations launched a new initiative in the Chicago region. Our vision? Chicago Wilderness: a thriving mosaic of natural areas, connected by greenways and wildlife corridors, embedded in the nation's third largest metropolis. In this vision, the region's human communities reclaim a cultural tradition of protecting and restoring the globally outstanding natural communities that enrich our lives. Today, more than 170 organizations join forces to transform this vision into reality. A regional biodiversity recovery plan, the result of 3 years of assessment and planning by scientists, land managers, educators, and policy strategists, sets priorities and determines the lines of action for the coalition. This regional agenda stems from our vision and recovery goals for each ecological community; it encourages targeted research initiatives that focus on characterizing our native biological diversity and on analyzing elements critical to its recovery. Ultimately, though, the long-term survival of our natural wealth rests on the support from the public. Although the challenges to conservation educators and communicators are many, Chicago Wilderness allows us to work together in understanding our audiences, channeling our resources, and creating novel approaches to engage the widest public in our conservation efforts.

The results of 21 total joint arthroplasties (13 knees, 8 hips) in 15 patients were reviewed. There were 13 men and 2 women with an average age of 38 years (range, 28 to 69 years). The mean follow-up period was 10.2 years (range, 2 to 23 years). Six patients died within an average of 10.6 years (range, 3 to 18 years) of joint arthroplasty. All patients died of AIDS. Deep infection developed in 6 joints. Knee Society scores improved significantly, but 13 repeat surgeries were required. An alarmingly high rate of complications was found after total knee and total hip arthroplasty in these patients with human immunodeficiency virus (HIV). Physicians and surgeons should be made aware of this high rate of complications after joint arthroplasty in patients with HIV and include a frank discussion of this information with their patients who are contemplating total joint arthroplasty., (Copyright 2003 Elsevier Inc. All rights reserved.)

A cDNA clone, which corresponds to an RNA transcript that accumulates in bean during the hypersensitive reaction, was isolated and designated Hra25 (for hypersensitive reaction associated). Hra25 is predicted to encode a UDP-glucosyltransferase. Northern analysis was used to study Hra25 transcript accumulation in bean in response to incompatible and compatible strains of Pseudomonas syringae, an Hrp- mutant, and wounding. Our data suggest that the Hra25 transcript is activated in response to specific avr-derived signals as well as non-avr, general signals.

In serum-containing medium, ascorbic acid induces maturation of prehypertrophic chick embryo sternal chondrocytes. Recently, cultured chondrocytes have also been reported to undergo maturation in the presence of bone morphogenetic proteins or in serum-free medium supplemented with thyroxine. In the present study, we have examined the combined effect of ascorbic acid, BMP-2, and serum-free conditions on the induction of alkaline phosphatase and type X collagen in chick sternal chondrocytes. Addition of either ascorbate or rhBMP-2 to nonconfluent cephalic sternal chondrocytes produced elevated alkaline phosphatase levels within 24-72 h, and simultaneous exposure to both ascorbate and BMP yielded enzyme levels at least threefold those of either inducer alone. The effects of ascorbate and BMP were markedly potentiated by culture in serum-free medium, and alkaline phosphatase levels of preconfluent serum-free cultures treated for 48 h with BMP+ascorbate were equivalent to those reached in serum-containing medium only after confluence. While ascorbate addition was required for maximal alkaline phosphatase activity, it did not induce a rapid increase in type X collagen mRNA. In contrast, BMP added to serum-free medium induced a three- to fourfold increase in type X collagen mRNA within 24 h even in the presence of cyclohexamide, indicating that new protein synthesis was not required. Addition of thyroid hormone to serum-free medium was required for maximal ascorbate effects but not for BMP stimulation. Neither ascorbate nor BMP induced alkaline phosphatase activity in caudal sternal chondrocytes, which do not undergo hypertrophy during embryonic development. These results indicate that ascorbate+BMP in serum-free culture induces rapid chondrocyte maturation of prehypertrophic chondrocytes. The mechanisms for ascorbate and BMP action appear to be distinct, while BMP and thyroid hormone may share a similar mechanism for induction.

"This paper begins by developing a language for ethical discourse on immigration and then examining the extent to which choices may be made at the micro-level and at the macro-level. States and individuals are examined as actors who are variously described as making choices or being choiceless. The concepts of cultural distance, reciprocity, the role of the individual and of the state and their interrelationships are evaluated in the perspective of choice. Whether an ethics of immigration can be successfully developed hinges on the degree of choice that individuals and state have or perceive themselves to have.", (excerpt)

In summary, we present data from affinity cross-linking and Scatchard plot analysis that demonstrates the presence of both IGF-I receptors and IGF-II receptors on the brush border membranes of rat intestinal mucosa. The brush border location of the IGF receptors suggests that IGFs available in the intestinal lumen may initiate signal transduction events by binding to receptors displayed on the mucosal lining. Our findings provide further support for the notion that at least some of the mitogenic stimulus for rapid proliferation of intestinal epithelium arises from lumenal IGFs, which may be supplied by apical secretions from the mucosa, or in saliva, colostrum, milk, chyme, or bile.

During development and fracture repair, endochondral bone formation is preceded by an orderly process of chondrocyte hypertrophy and cartilage matrix calcification. Analysis of calcifying versus noncalcifying cartilage has identified several differences in matrix proteins; among these are appearance of a novel collagen, type X, and decreased synthesis of type II collagen, the major component of cartilage matrix. In addition, there is a marked increase in alkaline phosphatase, an enzyme expressed at high levels in all mineralizing tissues. Cultured chondrocytes can be induced to undergo these changes in gene expression and to produce calcified matrix by exposure to ascorbic acid. The mechanism by which ascorbate produces these changes has been examined by analyzing the effect of the vitamin on prehypertrophic chick embryo sternal chondrocytes. Nuclear run-on assays demonstrated that ascorbate alters mRNA levels in chondrocytes by changing the transcription rates. The fact that marked changes in mRNA levels require 1-2 days of ascorbate exposure suggested that the effect of this vitamin on gene transcription may be secondary to other, earlier ascorbate-induced effects. Since cells cultured with ascorbate produce a collagen-enriched matrix, we examined the hypothesis that transcriptional changes were secondary to altered cell-matrix interactions. Chondrocytes were cultured after attachment to tissue culture plastic, in suspension, or on plates coated with collagen type I. Comparison of alkaline phosphatase activity with and without ascorbate addition demonstrated that under all of these conditions, induction of enzyme was dependent on the presence of ascorbate. When plates containing ascorbate-conditioned chondrocyte matrix were used as substrate for naive chondrocytes, the cells continued to require ascorbate for induction of high levels of alkaline phosphatase and type X collagen mRNA. Addition of the hydroxylation inhibitor, 3,4-dehydroproline, caused marked inhibition of collagen secretion as well as accumulation of underhydroxylated collagens within the cells. However, even in the presence of this inhibitor ascorbate was effective in inducing elevated alkaline phosphatase and type X collagen. These results indicate that the ability of ascorbate to induce chondrocyte hypertrophy does not depend on production of a collagen-rich matrix.

Adult vertebrates require a continuous supply of osteoblasts for both bone remodeling and regeneration during fracture repair. This implies the existence of a reservoir of cells in the body capable of osteogenesis. One source of these osteoprogenitors is the stem cells within the fibroblastic component of bone marrow stroma. Mature osteoblasts are characterized by high alkaline phosphatase and osteopontin levels, combined with expression of the bone-specific matrix proteins osteocalcin and bone sialoprotein and the capacity for matrix mineralization. We have used these markers to define the conditions permitting rapid osteoblast differentiation from cultured bone marrow stromal cells. Osteoblastic differentiation was induced by continuous culture with 10(-8) M dexamethasone (dex) which stimulated alkaline phosphatase (AP) activity and mRNA levels as well as osteopontin, bone sialoprotein, and osteocalcin mRNA by Day 8 of culture; coaddition of 10(-8) M 1,25-dihydroxyvitamin D3 (vitamin D) with dex was essential for high osteocalcin mRNA expression. Recombinant bone morphogenetic protein-2 (BMP-2) exerted similar effects to dex and acted in synergy with dex to yield greatly elevated AP activity as well as increased levels of osteoblastic mRNAs. Using in situ hybridization to detect the presence of mRNAs in individual cells, it was shown that appearance of osteopontin mRNA preceded AP mRNA, and was expressed in dex-treated cell colonies as early as Day 4. Quantitation of cell surface AP protein by flow cytometry indicated that culture with dex or BMP-2 produced a mixed population of cells with low AP (dim cells) and cells with high AP levels, while the combination of dex + BMP-2 yielded very few dim cells and a population of cells containing higher AP levels than with either inducer alone. When the dim population from dex-treated cells was sorted and recultured with inducers, these cultures developed high AP levels and were able to deposit a mineralized matrix. Thus, treatment of marrow stromal cells with inducer results in a population of mature osteoblasts as well as a population of undifferentiated cells which retains the capacity for osteoblastic differentiation with further exposure to inducers. These data demonstrate that stem cells within the stromal compartment of bone marrow are capable of rapidly acquiring osteoblast features and suggest a potential role for glucocorticoids in combination with BMP-2 and vitamin D in stages of osteogenic development.

Cells from a pulmonary or bronchial origin were analyzed with flow cytometry to assess the sensitivity and specificity of this method in diagnosing malignancy. In all instances, cells submitted for flow cytometry analysis were excess cells from specimens submitted for routine cytology. Less than 3% of all samples were rejected for insufficient material. Overall sensitivity from all sources was 86%, specificity 96%. Although cytology results were the standard for determining accuracy of flow cytometry, in a few patients cytology appeared normal and initial evidence for malignancy was obtained from flow cytometry. For this reason, flow cytometry may be a valuable adjunctive technology in the diagnosis of malignancy.

Photolysis of solutions containing 4-azido-7-phenylpyrazolo-[1,5a]-1,3,5-triazine (APPT) and calmodulin-sensitive cyclic nucleotide phosphodiesterase resulted in reduction of both cyclic GMP and cyclic AMP hydrolytic activity. The inactivation was dependent upon both time of exposure to ultraviolet irradiation and the initial concentration of APPT. The photo-induced inactivation could be attenuated by the presence of cyclic GMP, 1-methyl-3-isobutylxanthine, and papaverine. alpha-Chymotrypsin treatment caused the enzyme to be fully active in the absence of calmodulin but this treatment did not alter the ability of APPT to inactivate the enzyme. Thus, inhibition of calmodulin-binding did not contribute to the photo-induced inactivation. These data indicate that APPT acts as a photoaffinity agent to covalently modify the APPT-binding site of calmodulin-sensitive phosphodiesterase.