Diagnostic dilemmas: a multi-institutional retrospective analysis of adrenal incidentaloma pathology based on radiographic size

Introduction/background

Adrenal incidentalomas (AIs) are masses > 1 cm found incidentally during radiographic imaging. They are present in up to 4.4% of patients undergoing CT scan, and incidence is increasing with usage and sensitivity of cross-sectional imaging. Most result in diagnosis of adrenal cortical adenoma, questioning guidelines recommending removal of all AIs with negative functional workup. This retrospective study analyzes histological outcome based on size of non-functional adrenal masses.

Material and methods

10 years of data was analyzed from two academic institutions. Exclusion criteria included patients with positive functional workups, those who underwent adrenalectomy during nephrectomy, < 18 years, and incomplete records. AI radiologic and histologic size, histologic outcome, laterality, imaging modality, gender, and age were collected. T-test was used for comparison of continuous variables, and the two-sided Fisher’s exact or chi-square test were used to determine differences for categorical variables. Univariate analysis of each independent variable was performed using simple logistic regression.

Results

73 adrenalectomies met the above inclusion criteria. 60 were detected on CT scan, 12 on MRI, and one on ultrasound. Eight of 73 cases resulted in malignant pathology, 3 of which were adrenocortical carcinoma (ACC). Each ACC measured > 6 cm, with mean radiologic and pathologic sizes of 11.2 cm and 11.3 cm. Both radiologic and pathologic size were significant predictors of malignancy (p = 0.008 and 0.011).

Conclusions

Our results question the generally-accepted 4 cm cutoff for excision of metabolically-silent AIs. They suggest a 6 cm threshold would suffice to avoid removal of benign lesions while maintaining sensitivity for ACC.

Impact of maternal medication for opioid use disorder on neurodevelopmental outcomes of infants treated for neonatal opioid withdrawal syndrome

BACKGROUND

Increasing rates of maternal opioid use disorder has led to greater number of opioid exposed newborns (OENs). Maternal enrollment in medication for opioid use disorder (MOUD) program improves short term neonatal outcomes. This study aimed at assessing neurobehavioral outcomes for OENs.

METHODS

Retrospective observational cohort study of OENs between Jul 2006 and Dec 2018. Two study groups were identified as initiation of medication for opioid use disorder (MOUD) prior to diagnoses of pregnancy or after. Primary outcome variables were enrollment in and duration of EI services. Secondary outcome variable was diagnoses of a behavioral and/or developmental disorder (BDD) during the study period.

RESULTS

Of 242 infants, 113 were enrolled in EI and BDD diagnoses data was available for all infants [age range 6 to 12 years], 82% infants had exposure to maternal MOUD, while 18% were exposed to either maternal prescription non-MOUD opioids or illicit opioids. Maternal MOUD initiation prior to pregnancy was associated with improved short term outcomes for OENs. Almost a third of infants were diagnosed with a BDD with no differences between the two study groups.

CONCLUSION

Early initiation of maternal MOUD improved short term outcomes and discharge disposition for OENs. Prolonged in-utero exposure to opioids presents a potential for negative impact on neurodevelopmental and behavioral outcomes. These risks must be considered to increase access and adherence to EI services, as well as to focus on non-opioid based maternal MOUD. Longitudinal studies assessing the safety of MOUD on short and long-term child health outcomes are needed.

Watershed influences on the structure and function of riparian wetlands associated with headwater streams - Kenai Peninsula, Alaska

Riparian wetlands are dynamic components of landscapes. Located between uplands and aquatic environments, riparian habitats intercept sediments and nutrients before they enter aquatic environments. They are a source of organic matter and nutrients to aquatic systems, and they provide important habitat for animals, often serving as corridors for the movement of animals between habitats in fragmented landscapes. In this project, we focused on the structure and function of riparian wetlands associated with headwater streams in Alaska that serve as nursery habitats for juvenile salmonids. We asked whether or not the structure and function of headwater wetlands differed between watersheds with and without nitrogen-fixing Alder (Alnus spp.). We found that the aboveground biomass of riparian vegetation was higher in the watershed with Alder, but the largest differences were in the litter layer and belowground where vegetation in the watershed with no Alder had significantly higher root biomass. Interstitial water chemistry also differed between the study sites with significantly higher inorganic N and significantly different characteristics of colored dissolved organic matter at the site with Alder on the watershed. The biomass of litter that hung over the creek bank was less at the site with Alder on the watershed and an in situ decomposition experiment showed significant differences between the two systems. Results of the research demonstrates that watershed characteristics can impact the ecology of headwater streams in ways that had not been previously recognized.

Early Head Start, Pediatric Dental Use, and Oral Health-Related Quality of Life

The objective of the study was to examine the mediating effect of child dental use on the effectiveness of North Carolina Early Head Start (EHS) in improving oral health-related quality of life (OHRQoL). In total, 479 parents of children enrolled in EHS and 699 parents of Medicaid-matched children were interviewed at baseline when children were approximately 10 mo old and 24 mo later. In this quasi-experimental study, mediation analysis was performed using the counterfactual framework analysis, which employed 2 logit models with random effects: 1) for the mediator as a function of the treatment and covariates and 2) for the outcome as a function of the treatment, mediator, and covariates. The covariates were baseline dental OHRQoL, dental need, survey language, and a propensity score. We used in-person computer-assisted, structured interviews to collect information on demographic characteristics and dental use and to administer the Early Childhood Oral Health Impact Scale, a measure of OHRQoL. Dental use had a mediation effect in the undesired direction with a 2-percentage point increase in the probability of any negative impact to OHRQoL (95% confidence interval [CI], 0.3%-3.9%). Even with higher dental use by EHS participants, the probability of any negative impact to OHRQoL was approximately 8 percentage points lower if an individual were moved from the non-EHS group to the EHS group (95% CI, -13.9% to -1.2%). EHS increases child dental use, which worsens family OHRQoL. However, EHS is associated with improved OHRQoL overall. Knowledge Transfer Statement: Study results can inform policy makers that comprehensive early childhood education programs improve oral health-related quality of life (OHRQoL) for disadvantaged families with young children in pathways outside of clinical dental care. This awareness and its promotion can lead to greater resource investments in early childhood education programs. Information about the negative impacts of dental use on OHRQoL should lead to the development and testing of strategies in dentistry and Early Head Start to improve dental care experiences.

Effects of enamel fluorosis and dental caries on quality of life

The objectives of this study were to determine the impact of enamel fluorosis and dental caries on oral health-related quality of life (OHRQoL) in North Carolina schoolchildren and their families. Students (n = 7,686) enrolled in 398 classrooms in grades K-12 were recruited for a onetime survey. Parents of students in grades K-3 and 4-12 completed the Early Childhood Oral Health Impact Scale (ECOHIS) and Family Impact Scale (FIS), respectively. Students in grades 4-12 completed the Child Perceptions Questionnaire (CPQ8-10 in grades 4-5; CPQ11-14 in grades 6-12). All students were examined for fluorosis (Dean's index) and caries experience (d2-3fs or D2-3MFS indices). OHRQoL scores (sum response codes) were analyzed for their association with fluorosis categories and sum of d2-3fs and D2-3MFS according to ordinary least squares regression with SAS procedures for multiple imputation and analysis of complex survey data. Differences in OHRQoL scores were evaluated against statistical and minimal important difference (MID) thresholds. Of 5,484 examined students, 71.8% had no fluorosis; 24.4%, questionable to very mild fluorosis; and 3.7%, mild, moderate, or severe fluorosis. Caries categories were as follows: none (43.1%), low (28.6%), and moderate to high (28.2%). No associations between fluorosis and any OHRQoL scales met statistical or MID thresholds. The difference (5.8 points) in unadjusted mean ECOHIS scores for the no-caries and moderate-to-high caries groups exceeded the MID estimate (2.7 points) for that scale. The difference in mean FIS scores (1.5 points) for the no-caries and moderate-to-high groups exceeded the MID value (1.2 points). The sum of d2-3fs and D2-3MFS scores was positively associated with CPQ11-14 (B = 0.240, p < .001), ECOHIS (B = 0.252, p ≤ .001), and FIS (B = 0.096, p ≤ .01) scores in ordinary least squares regression models. A child's caries experience negatively affects OHRQoL, while fluorosis has little impact.

Birthdates and number of neurons in the serotonergic raphe nuclei in the rat with prenatal protein malnutrition

The effect of prenatal protein deprivation on timing of neurogenesis and on number of neurons generated in the serotonergic dorsal (DR) and median raphe (MR) nuclei of the rat was studied. These neurons are of interest because their neurogenesis occurs during the period of malnutrition and their axonal projections participate in the earliest stages of brain development. In this study, dams were maintained on a 25% casein diet or a 6% casein diet 5 weeks prior to mating and throughout pregnancy. At birth, all pups were cross-fostered to dams on a 25% casein diet. Bromodeoxyuridine, a thymidine analog that is incorporated into nuclear deoxyribonucleic acid during the cell cycle synthetic phase, was used as a marker of neurogenesis. Bromodeoxyuridine was administered on either embryonic day 11, 12, 13 or 14. On postnatal day 30, serial sections of raphe nuclei were processed with bromodeoxyuridine immunocytochemistry to determine the number of raphe cells generated on each day and with Nissl stain to determine the total number of cells generated. There were no significant differences between the two diet groups in timing of generation or in total number of cells generated, indicating that neurogenesis of these early generated neurons appears unaffected by concomitant protein deprivation.

Sulfation of indoxyl by human and rat aryl (phenol) sulfotransferases to form indoxyl sulfate

The aim of this study was to identify sulfotransferase (SULT) isoform(s) responsible for the formation of indoxyl sulfate from indoxyl (3-hydroxyindole). Indoxyl was incubated together with the co-substrate 3'-phosphoadenosine 5'-phosphosulfate (PAPS) and either human or rat liver cytosol or recombinant sulfotransferase enzymes. Formation of indoxyl sulfate from indoxyl was measured by HPLC and used for determination of sulfonation rates. Both cytosols sulfonated indoxyl with apparent Km values of 6.8 +/- 0.9 microM for human and 3.2 +/- 0.6 microM for rat cytosol. To help identify the isoform(s) of SULT responsible for indoxyl sulfate formation, indoxyl was incubated with human and rat liver cytosols and PAPS in the presence of isoform-specific SULT inhibitors. No inhibition was observed by DHEA, a specific hydroxysteroid sulfotransferase inhibitor, nor by oestrone, an inhibitor of oestrogen sulfotransferase. However, an aryl (phenol) sulfotransferase inhibitor, 2,6-dichloro-4-nitrophenol (DCNP), inhibited the formation of indoxyl sulfate with a IC50 values of 3.2 microM for human and 1.0 microM for rat cytosol indicating that human and rat aryl (phenol) sulfotransferases are responsible for the formation of indoxyl sulfate. When indoxyl was incubated with SULT1A1*2, a human recombinant aryl SULT, an apparent Km value of 5.6 +/- 1.8 microM was obtained. Kinetic studies with human and rat cytosols and human recombinant SULT1A1*2 gave similar kinetic values indicating that human and rat aryl sulfotransferases efficiently catalyze the formation of indoxyl sulfate, an important uremic toxin metabolite.

Use of granulocyte colony-stimulating factor after high-dose chemotherapy and autologous peripheral blood stem cell transplantation: what is the optimal timing?

Administration of granulocyte colony-stimulating factor to patients undergoing high-dose chemotherapy and autologous peripheral blood stem cell transplantation accelerates neutrophil recovery and decreases hospitalization time. The optimal timing for granulocyte colony-stimulating factor infusion remains unknown. In this retrospective, case-controlled, two-armed study, we reviewed our experience at Hahnemann University Hospital to determine whether initiating granulocyte colony-stimulating factor infusions on posttransplant day 0 versus day 8 affects neutrophil recovery time, posttransplant discharge date, total hospital days after high-dose chemotherapy, and autologous peripheral blood stem cell transplantation. All patients hospitalized between 1994 and 1998 at Hahnemann University Hospital, Bone Marrow Transplantation Unit with breast cancer or non-Hodgkin's lymphoma, who underwent high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation and received granulocyte colony-stimulating factor either on posttransplant day 0 (16 patients) or day 8 (16 patients). The day 0 and day 8 groups had no statistically significant differences in age, sex, weight, height, body surface area, disease characteristics, pretransplant harvesting or conditioning regimens, or transplant CD34+ cell counts. Our main outcome measure was the mean time to reach absolute neutrophil count greater than or equal to 0.5 x 10(9)/l, the number of hospital days after transplant, and the total hospital days. The mean days to neutrophil recovery (10.56 versus 9.68, p = 0.48), posttransplant hospital days (13.62 versus 12.81, p = 0.39), and total hospital days (20.25 versus 20.25, p = 1.00) were not significantly different between day 8 and day 0 groups, respectively. No significant effects on neutrophil recovery time, posttransplant hospital days, or total hospital days were observed with the initial granulocyte colony-stimulating factor infusion on day 0 versus day 8 after transplant. Delayed administration may allow substantial cost savings (US$200 x 8 approximately equal to US $1,600 per patient) without affecting clinical outcome. More studies are needed to determine whether greater delay is feasible.

Hepatic microsomal metabolism of indole to indoxyl, a precursor of indoxyl sulfate

The aim of our study was to determine which microsomal cytochrome P450 isozyme(s) were responsible for the microsomal oxidation of indole to indoxyl, an important intermediate in the information of the uremic toxin indoxyl sulfate. Indole was incubated together with an NADPH-generating system and rat liver microsomes. Formation of indigo, an auto-oxidation product of indoxyl, was used to determine the indole-3-hydroxylation activity. Apparent Km and Vmax values of 0.85 mM and 1152 pmol min(-1) mg(-1) were calculated for the formation of indoxyl from indole using rat liver microsomes. The effects of various potential inducers and inhibitors on the metabolism of indole to indoxyl by rat liver microsomes were studied to elucidate the enzymes responsible for metabolism. Studies with general and isozyme-specific P450 inhibitors demostrated that P450 enzymes and not FMO are responsible for the formation of indoxyl. In the induction studies, rate of indoxyl formation in the microsomes from untreated vs induced rats correlated nearly exactly with the CYP2E1 activity (4-nitrophenol 2-hydroxylation). These results suggests that CYP2E1 is the major isoform for the microsomal oxidation of indole to indoxyl.

Structure-function modeling of the interactions of N-alkyl-N-hydroxyanilines with rat hepatic aryl sulfotransferase IV

Although previous investigations have clearly shown that N-hydroxy arylamines and N-hydroxy heterocyclic amines are substrates for sulfotransferases, relatively little is known about which structural features of the N-hydroxy arylamines are important for sulfation to occur. The purpose of this investigation was to determine the extent to which secondary N-alkyl-N-hydroxy arylamines interact with aryl sulfotransferase (AST) IV (also known as tyrosine-ester sulfotransferase or ST1A1) and to evaluate these interactions using molecular modeling techniques. AST IV is a major cytosolic sulfotransferase in the rat, and it catalyzes the sulfation of various phenols, benzylic alcohols, arylhydroxamic acids, oximes, and primary N-hydroxy arylamines. In this study, three secondary N-hydroxy arylamines, N-hydroxy-N-methylaniline, N-ethyl-N-hydroxyaniline, and N-hydroxy-N-n-propylaniline, were found to be substrates for the purified rat hepatic AST IV. However, when the N-alkyl substituent was an n-butyl group (i.e., N-n-butyl-N-hydroxyaniline), the interaction with the enzyme changed from that of a substrate to competitive inhibition. This change in specificity was further explored through the construction and use of a model for AST IV based on mouse estrogen sulfotransferase, an enzyme whose crystal structure has been previously determined to high resolution. Molecular modeling techniques were used to dock each of the above N-hydroxy arylamines into the active site of the homology model of AST IV and determine optimum ligand geometries. The results of these experiments indicated that steric constraints on the orientation of binding of secondary N-alkyl-N-hydroxy arylamines at the active site of AST IV play a significant role in determining the nature of the interaction of the enzyme with these compounds.

In vitro bioactivation of N-hydroxy-2-amino-alpha-carboline

2-Amino-alpha-carboline (A alpha C) is a mutagenic and carcinogenic heterocyclic amine present in foods cooked at high temperature and in cigarette smoke. The mutagenic activity of A alpha C is dependent upon metabolic activation to N-hydroxy-A alpha C (N-OH-A alpha C); however, the metabolism of N-OH-A alpha C has not been studied. We have synthesized 2-nitro-alpha-carboline and N-OH-A alpha C and have examined in vitro bioactivation of N-OH-A alpha C by human and rodent liver cytosolic sulfotransferase(s) and acetyltransferase(s) and by recombinant human N-acetyltransferases, NAT1 and NAT2. The sulfotransferase-dependent bioactivation of N-OH-A alpha C by human liver cytosol exhibited large inter-individual variation (0.5-75, n = 14) and was significantly higher than bioactivation of N-hydroxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP). Correlation and inhibition studies suggested that the isoform of sulfotransferase primarily responsible for bioactivation of N-OH-A alpha C in human liver cytosol is SULT1A1. O-Acetyltransferase-dependent bioactivation of N-OH-A alpha C by human liver cytosol also exhibited large inter-individual variation (16-192, n = 18). In contrast to other N-hydroxy heterocyclic amines, which are primarily substrates only for NAT2, both NAT1 and NAT2 catalyzed bioactivation of N-OH-A alpha C. The rate of bioactivation of N-OH-A alpha C by both NAT1 and NAT2 was significantly higher than that for N-OH-PhIP. In rat and mouse liver cytosols, the level of sulfotransferase-dependent bioactivation of N-OH-A alpha C was similar to the level in the high sulfotransferase activity human liver cytosol. The level of O-acetyltransferase-dependent bioactivation of N-OH-A alpha C in rat liver cytosol was also comparable with that in the high acetyltransferase activity human liver cytosol. However, the level of O-acetyltransferase-dependent bioactivation of N-OH-A alpha C in mouse liver cytosol was comparable with that in the low acetyltransferase activity human liver cytosol. In contrast to N-OH-PhIP, bioactivation of N-OH-A alpha C was not inhibited by glutathione S-transferase activity; however, DNA binding of N-acetoxy-A alpha C was inhibited 20% in the presence of GSH. These results suggest that bioactivation of N-OH-A alpha C may be a significant source of DNA damage in human tissues after dietary exposure to AalphaC and that the relative contribution of each pathway to bioactivation or detoxification of N-OH-A alpha C differs significantly from other N-hydroxy heterocyclic or aromatic amines.

Concentrations of suspended particulate organic carbon in the tidal Yorkshire Ouse River and Humber Estuary

Data are presented for particulate organic carbon (POC) and particulate nitrogen (PN) concentrations in the Humber Estuary and tidal River Ouse Estuary. The POC data were derived from approximately monthly surveys and are consistent with data reported for suspended particulate matter (SPM) in the non-tidal River Ouse (the freshwater river) and with SPM, or bed sediments, in estuarine ecosystems such as the Mississippi, Delaware, San Francisco Bay, Tolo Harbour, the Vellar Estuary and Cochin Backwater, as well as the Loire, Gironde, Ems and Tamar Estuaries. Relative to the dry weight of SPM, the Humber-averaged organic carbon and nitrogen percentages during the year February 1995-March 1996 were 2.6 +/- 0.6% (mean and S.D.) and 0.21 +/- 0.04%, respectively. The ratio of Humber-averaged POC to Humber-averaged PN was 13 +/- 3. Higher POC levels were observed near the Humber's mouth and in the adjacent coastal zone during 'bloom' conditions, and in the upper estuarine reaches during large, winter and springtime freshwater inflows. At these times of high runoff, the POC content of SPM increased progressively up-estuary from the coastal zone to the tidal River Ouse. When inflows became very low, during late spring to early autumn of 1995, both the freshwater-saltwater interface (FSI) and the strengthening turbidity maximum (TM) moved further up-estuary and the POC content of SPM in the upper reaches of the Ouse became lower compared with that immediately down-estuary. This led to a poorly defined POC maximum near the confluence of the Humber, Ouse and Trent, before POC eventually decreased again towards the coastal zone. The lower POC contents in the upper estuarine reaches of the tidal Ouse may have been partly due to POC respiration by heterotrophic bacteria attached to SPM within the TM, consistent with the severe oxygen depletion observed there during high turbidity, summertime spring tides.

Detoxification of carcinogenic aromatic and heterocyclic amines by enzymatic reduction of the N-hydroxy derivative

The metabolic activation pathways associated with carcinogenic aromatic and heterocyclic amines have long been known to involve N-oxidation, catalyzed primarily by cytochrome P4501A2, and subsequent O-esterification, often catalyzed by acetyltransferases (NATs) and sulfotransferases (SULTs). We have found a new enzymatic mechanism of carcinogen detoxification: a microsomal NADH-dependent reductase that rapidly converts the N-hydroxy arylamine back to the parent amine. The following N-OH-arylamines and N-OH-heterocyclic amines were rapidly reduced by both human and rat liver microsomes: NOH-4-aminoazobenzene, N-OH-4-aminobiphenyl (N-OH-ABP), N-OH-aniline, N-OH-2-naphthylamine, N-OH-2-aminofluorene, N-OH-4,4'-methylenebis(2-chloroaniline) (N-OH-MOCA), N-OH-1-naphthyamine, N-OH-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP), N-OH-2-amino-alpha-carboline (N-OH-AalphaC), N-OH-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (N-OH-MeIQx), and N-OH-2-amino-3-methylimidazo[4,5-f]quinoline (N-OH-IQ). In addition, primary rat hepatocytes and human HepG2 cells efficiently reduced N-OH-PhIP to PhIP. This previously unrecognized detoxification pathway may limit the bioavailability of carcinogenic N-OH heterocyclic and aromatic amines for further activation, DNA adduct formation, and carcinogenesis.

Formation of DNA adducts of the food-derived mutagen 2-amino-9H-pyrido-[2,3-b]indole (A(alpha)C) and bioassay of mammary gland carcinogenicity in Sprague-Dawley rats

2-amino-9H-pyrido[2,3-b]indole (AalphaC) is a heterocyclic amine found at relatively high concentrations in barbecued or grilled meats. In the current study, the mammary gland carcinogenicity of AalphaC was examined in female Sprague-Dawley rats given 10 doses of AalphaC (75 mg/kg, orally, once per day starting at 43 days of age) and placed on a defined high-fat diet (23.5% corn oil), a strong promotional factor for rat mammary gland carcinogenesis. Within 1 year, one out of 20 rats dosed with AalphaC developed a tubulopapillary carcinoma, indicating that the bioassay was largely negative. As DNA adduct formation is considered to play a role in carcinogenesis, AalphaC-DNA adduct levels were measured in the mammary gland and other tissues by the 32P-postlabelling method. Under intensification conditions, one major adduct and up to three minor adducts were detected in isolated mammary gland epithelial cells and other tissues (liver, stomach, small intestine, colon and kidney) of AalphaC-treated rats; the adduct patterns were similar in all tissues examined. The major adduct, comprising 60-100% of total DNA adduct levels in tissues, was chromatographically identical to the principal adduct found in 3'-dGp-AalphaC (synthesized by reacting 3'-phospho-2'-deoxyguanosine (3'-dGp) with N-acetoxy-AalphaC). Of the tissues examined, the highest AalphaC-DNA adduct levels were found in the liver. In male rats given a single dose of AalphaC (75 mg/kg, orally, 3 hr prior to necropsy), no AalphaC-DNA adducts were detected in extrahepatic tissues. In female rats given a single dose or 12 daily doses of AalphaC, hepatic DNA adduct levels were at least 12-13-fold higher than those in any other tissue. Mean total AalphaC-DNA adduct levels in mammary gland epithelial cells and liver from female rats given multiple doses of AalphaC were 3.5 and 50.7 (RAL x 10(7)), respectively. Although factors in addition to DNA adduct formation are likely to play a role in mammary gland carcinogenesis, the results suggest that the weak mammary gland carcinogenicity of AalphaC may in part be associated with low AalphaC-DNA adduct levels in the mammary gland epithelium.

Bioactivation of the cooked food mutagen N-hydroxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine by estrogen sulfotransferase in cultured human mammary epithelial cells

Cooked food mutagens from fried meat and fish have recently been suggested to contribute to the etiology of breast cancer. Thus, the most prevalent of these compounds, i.e. 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, or rather its more mutagenic N-hydroxylated metabolite (N-OH-PhIP), forms DNA adducts in mammary cells, including human mammary epithelial (HME) cells. The objective of this study was to determine the involvement of estrogen sulfotransferase (EST), the only sulfotransferase identified in HME cells, in the further bioactivation of N-OH-PhIP. These studies were done in vitro using human recombinant EST and in intact HME cells. Human recombinant EST increased the covalent binding of [3H]N-OH-PhIP to calf thymus DNA approximately 3.5-fold in the presence of the sulfotransferase co-substrate 3'-phosphoadenosine-5'-phosphosulfate at each N-OH-PhIP concentration (1, 10 and 100 microM) (n = 6, P < 0.001). In contrast, EST did not catalyze the DNA binding of two other cooked food mutagens, N-hydroxy-2-amino-3-methylimidazo[4,5-f]quinoline and N-hydroxy-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, which are mainly hepatocarcinogens. Cultured HME cells displayed high EST activity, which could be completely inhibited by 1 microM estrone. When the cells were incubated with [3H]N-OH-PhIP, binding to native DNA occurred at 60-240 pmol/mg DNA. This binding was inhibited to 55% of control by 1 microM estrone (P < 0.01, n = 8), suggesting that EST plays a significant role in carcinogen bioactivation in human breast tissue.

The dash for dentures: the turbulent introduction of NHS dentistry

With the formal launch of the National Health Service on the evening of Sunday, July 4, 1948, the pattern of dental treatment in Britain changed dramatically. This change altered the lives of everyone connected with the provision of this treatment and, for dentists in particular, working life would never be the same again. But how did they come about?

Oxidation-dependent inactivation of aryl sulfotransferase IV by primary N-hydroxy arylamines during in vitro assays

The sulfation of primary N-hydroxy arylamines is a critical intermediate step in the bioactivation of many carcinogenic arylamines, arylamides and nitroaromatics. However, the study of this reaction in vitro is often complicated by the chemical instability of these molecules. We have examined the stability of two highly purified N-hydroxy arylamines, N-hydroxyaniline and N-hydroxy-2-aminofluorene, under different oxidative reaction conditions pertinent to the assay of sulfotransferases. Furthermore, these compounds, as well as the products of their oxidative degradation, were examined for their interactions with homogeneous aryl sulfotransferase (AST) IV. Under reaction conditions where oxidative degradation of the N-hydroxy arylamines occurred, N-hydroxyaniline and N-hydroxy-2-aminofluorene produced time-dependent and irreversible inhibition of AST IV. While this inhibition was not dependent upon the presence of 3'-phosphoadenosine 5'-phosphosulfate in the reaction mixture, analysis of the N-hydroxy arylamines by UV spectroscopy showed that the inhibition of AST IV did require non-enzymatic oxidation of the N-hydroxy arylamine. Under reaction conditions that prevented the oxidative degradation of N-hydroxyaniline, this N-hydroxy arylamine was a substrate for AST IV. Likewise, under similar conditions, 4-chloro-N-hydroxyaniline was also a substrate for the enzyme. In contrast, no AST IV catalyzed sulfation of N-hydroxy-2-aminofluorene was detected under conditions that prevented the oxidation of N-hydroxy-2-aminofluorene. Adequate protection of these N-hydroxy arylamines from oxidative degradation required the addition of L-ascorbic acid to reaction mixtures that had also been degassed and purged with argon. The irreversible inhibition of AST IV exhibited by these N-hydroxy arylamines, even in reaction mixtures where attempts were made to limit oxidative degradation by degassing and purging with argon, emphasized the importance of completely preventing such degradation when utilizing in vitro assays to assess the potential for an N-hydroxy arylamine to serve as a substrate for a specific sulfotransferase.

Gemcitabine. New first-line therapy for pancreatic cancer

Gemcitabine hydrochloride, a pyrimidine antimetabolite, recently was approved as first-line therapy for patients with locally advanced or metastatic adenocarcinoma of the pancreas. This agent also is indicated for use by patients previously treated with 5-FU. Using a new system to measure improvement in disease-related symptoms, two key clinical trials have demonstrated significant clinical benefit responses and a favorable adverse effect profile in patients receiving gemcitabine. With additional experience, the role of gemcitabine in pancreatic cancer, alone or in combination with other antineoplastic agents, will be defined further. The activity of gemicitabine against other malignancies such as ovarian, breast, bladder, small-cell and non-small-cell lung cancers also is being investigated actively.

Metabolism of 2-amino-alpha-carboline. A food-borne heterocyclic amine mutagen and carcinogen by human and rodent liver microsomes and by human cytochrome P4501A2

2-Amino-alpha-carboline (A alpha C) is a mutagenic and carcinogenic heterocyclic amine that is formed as a pyrolysis product during the high temperature cooking of food and the burning of tobacco. Human, rat, and mouse hepatic microsomes each catalyzed the NADPH-dependent oxidation of A alpha C to form six products separable by HPLC. The two major metabolites, which together accounted for approximately 85% of the total metabolism, were characterized by UV, fluorescence, proton magnetic resonance, and mass spectral analyses as 3-hydroxy-A alpha C and 6-hydroxy-A alpha C. The remaining 15% were judged to be N-hydroxy-A alpha C and its oxidation products, based on chromatographic and spectral comparisons with a standard, whose synthesis and characterization are also described. Although the proportions of each metabolite were similar across species and individuals, the overall rate of metabolism of A alpha C by human hepatic microsomes showed a wide interindividual variation (37-fold), with a mean activity that was comparable with that observed with rat or mouse liver microsomes. alpha-Naphthoflavone, a selective inhibitor for cytochromes P4501A1 and P4501A2, strongly inhibited formation of both ring-hydroxylation and N-oxidation products by human, rat, or mouse liver hepatic microsomes. In addition, A alpha C oxidation was strongly correlated (r = 0.98; p < 0.001) with the oxidation of 4-aminobiphenyl, a known selective substrate for human and rodent cytochromes P4501A2. Immunoblot analyses confirmed the presence of cytochromes P4501A2, and not P4501A1, in human liver microsomes. Additional studies using recombinant human cytochromes P450 show that high catalytic activity for A alpha C metabolism was associated with human cytochrome P4501A2. Lower, but significant activity was also noted for P4501A1 and P4502C10, which could have important implications for the metabolic activation of A alpha C extrahepatic tissues. Neither A alpha C metabolism nor immunoreactive cytochrome P4501A2 (or P4501A1) was detected in human pancreatic microsomes. Although further carcinogenicity and biomarker studies for A alpha C are needed, the high rate of A alpha C metabolism by human liver cytochrome P4501A2 suggests that humans with the rapid P4501A2 phenotype with may be more susceptible than rodents to this heterocyclic amine carcinogen.

Purification of bovine estrus-associated protein and localization of binding on sperm

An oviduct-specific, estrus-associated glycoprotein (EAP) of 85-95 kDa is detectable in both conditioned medium (CM) from oviductal explants and cannula-derived oviductal fluid (ODF). The objectives of this study were to purify EAP from both ODF and CM, to characterize the glycosylation of EAP, and to localize binding of EAP on sperm. EAP was purified from ODF by ammonium sulfate precipitation and ammonium sulfate back-extraction followed by electroelution from one-dimensional SDS-PAGE gels. EAP was recovered from CM by electroelution from SDS-PAGE gels. Purified EAP was used as antigen to produce polyclonal antibodies (anti-EAP), and the specificity of anti-EAP was demonstrated as a single band in Western blots of ODF. N-linked sugar residues were enzymatically removed from EAP purified from ODF. The resulting molecule was 7 kDa smaller and was similar in molecular mass to EAP derived from CM. Sperm were incubated with 35S-proteins synthesized by oviductal explant cultures. Autoradiographs of solubilized sperm membranes contained a 90-95-kDa protein that was confirmed by Western blotting to be EAP. EAP was localized on permeabilized membranes of sperm incubated in ODF by immunocytochemistry using polyclonal anti-EAP. EAP was bound to the head and middle piece of 97% of the sperm incubated for 4 h in ODF. From these results, we concluded that N-linked sugars account for approximately 8% of the molecular mass of ODF-derived EAP and that EAP binds to the head and middle piece of sperm.

Effect of bovine oviductal estrus-associated protein on the ability of sperm to capacitate and fertilize oocytes

At estrus, an oviduct-specific, estrus-associated glycoprotein (EAP) of molecular weight 85-95,000, is secreted by the oviductal epithelium and found in cannula-derived bovine oviductal fluid (ODF). The objectives of these studies were to determine if bovine sperm were capacitated by EAP in vitro, whether this effect differed for EAP derived from ODF versus conditioned medium from oviduct ampullar explants, and to determine if sperm capacitated in vitro with EAP-fertilized bovine eggs. Sperm were incubated for up to 6 hours with partially purified EAP derived from ODF and assessed for capacitation by their ability to undergo the acrosome reaction following exposure to lysophosphatidylcholine. At 4 hours of incubation, the number of capacitated sperm in treatments containing 50% ODF or EAP plus bovine serum albumin (BSA) was similar, and it was significantly greater than the number of capacitated sperm in treatments containing antibodies to EAP. Using purified EAP derived from ampullar explant-conditioned medium, twice the number of sperm were capacitated after 4 hours with EAP from conditioned medium or with ODF than with treatments containing anti-EAP. The fertilizing ability of sperm incubated with EAP was significantly greater than that for sperm incubated without EAP or with anti-EAP. We conclude that bovine EAP, derived from both ODF and in vitro cultures, promotes sperm fertilizing ability.

Purification of bovine estrus-associated protein and localization of binding on sperm

An oviduct-specific, estrus-associated glycoprotein (EAP) of 85-95 kDa is detectable in both conditioned medium (CM) from oviductal explants and cannula-derived oviductal fluid (ODF). The objectives of this study were to purify EAP from both ODF and CM, to characterize the glycosylation of EAP, and to localize binding of EAP on sperm. EAP was purified from ODF by ammonium sulfate precipitation and ammonium sulfate back-extraction followed by electroelution from one-dimensional SDS-PAGE gels. EAP was recovered from CM by electroelution from SDS-PAGE gels. Purified EAP was used as antigen to produce polyclonal antibodies (anti-EAP), and the specificity of anti-EAP was demonstrated as a single band in Western blots of ODF. N-linked sugar residues were enzymatically removed from EAP purified from ODF. The resulting molecule was 7 kDa smaller and was similar in molecular mass to EAP derived from CM. Sperm were incubated with 35S-proteins synthesized by oviductal explant cultures. Autoradiographs of solubilized sperm membranes contained a 90-95-kDa protein that was confirmed by Western blotting to be EAP. EAP was localized on permeabilized membranes of sperm incubated in ODF by immunocytochemistry using polyclonal anti-EAP. EAP was bound to the head and middle piece of 97% of the sperm incubated for 4 h in ODF. From these results, we concluded that N-linked sugars account for approximately 8% of the molecular mass of ODF-derived EAP and that EAP binds to the head and middle piece of sperm.

Pharmaceutical services and inpatient drug costs in bone marrow transplantation

A survey of U.S. bone marrow transplantation (BMT) programs was conducted to determine the role of pharmaceutical services in those programs and the pharmacy department resources allocated to support them. Surveys were sent to 92 U.S. BMT programs to solicit the following information: characteristics of the institution and the BMT program, extent of pharmacist involvement in the BMT program, and pharmacy resource allocation to the program. Fifty-five responses were received (60% response rate). BMT pharmacists were employed by 53 of these institutions (a total of 66 pharmacists). BMT pharmacists at 49 of the 53 institutions (92%) received their salary from the department of pharmacy. Common BMT pharmacist responsibilities included managing adverse effects (100% of respondents), adjusting medication doses (96%), providing drug information (94%), participating in BMT team rounds (87%), maintaining medication profiles (85%), and developing medication protocols (81%). Inpatient BMT-related drug costs (reported by 37 respondents) averaged 12% of the pharmacy's annual inpatient drug budget. One or more pharmacists were members of the BMT team at 46 of 53 institutions. BMT-related drug costs accounted for 12% of the total inpatient drug budget at the 37 institutions reporting cost data.

A revised map location for the histidine utilization genes in Pseudomonas putida

The histidine utilization genes hutH and hutU of Pseudomonas putida ATCC 12633 have been mapped by interrupted mating and transduction to a location at approximately 43 minutes on the chromosome, closely linked to ser-800 and met-400 markers previously shown to be at 46 and 42 minutes, respectively. Since restriction enzyme mapping and cloning results have established that all genes associated with the hut pathway are contiguous, earlier maps of this strain which place these genes near 10 minutes on the chromosome in a superoperonic catabolic cluster are in error.

Stability of midazolam hydrochloride in parenteral nutrient solutions

The compatibility and stability of midazolam hydrochloride in three parenteral nutrient (PN) solutions and the stability of 15 amino acids in the presence of midazolam hydrochloride were studied. Six combinations of three PN solutions with amino acid concentrations of 1.5%, 2.5%, and 5% and two midazolam concentrations (0.1 and 0.5 mg/mL) were prepared in triplicate and stored at room temperature under normal fluorescent lighting. Duplicate samples were visually inspected for color change, precipitation, or gas formation and tested for pH. The samples were evaluated for midazolam and amino acid content by high-performance liquid chromatography at zero, one, three, and five hours. Midazolam and amino acid concentrations did not change significantly during the study. There was no evidence of color change, precipitation, or gas formation with any midazolam-PN solution combination when the combinations were examined visually and under a microscope, and no substantial changes in pH occurred. Midazolam 0.1 and 0.5 mg/mL (as the hydrochloride salt) was stable in the three PN solutions studied; in addition, the amino acids present in the 1.5%, 2.5%, and 5% amino acid PN solutions were stable when combined with midazolam at concentrations of 0.1 and 0.5 mg/mL.

Influence of fragment size on DNA quantitation using DNA-binding proteins and a sensor-based analytical system: applications in the testing of biological products

A novel immunoassay system which rapidly quantifies picogram levels of total DNA was characterized with respect to the effects of DNA length. Nine chromatographically purified HaeIII restriction fragments of phi X174 were tested. Assay performance was found to be dependent on both the amount and length of DNA present in the sample. DNA fragments longer than 100 base pairs (bp) could be quantitatively detected with this system. Fragments shorter than 100 bp inhibited assay performance and thus could be detected through the use of inhibition studies; however, only qualitative information could be obtained. DNA fragments approximately 10 nucleotides in length had no apparent effect on assay performance. The size of the binding site (number of bases) required for each DNA-binding protein to bind to a nucleic acid fragment is suggested as an explanation for the observed influence of DNA size on assay performance. The total DNA assay was used in conjunction with a Pharmacia FPLC system to characterize the size distribution and amount of DNA in two partially purified biopharmaceutical samples. The results indicate that the majority of residual DNA in these samples is less than 600 bp in length. This technique can be used to rapidly determine the DNA size distribution in an in-process or final product biopharmaceutical sample. This data can then be used in process design and optimization for removal of residual DNA in biological products.

Sodium-dependent phosphate transport in primary cultures of renal tubule cells from young and adult rats

The transport of phosphate by primary cultures of renal cells from young (5-6 weeks) and adult (10-12 months) rats was studied. Renal tubule cells isolated from young and adult groups exhibited typical epithelial morphology and similar growth rates. The Na-dependent phosphate uptake was saturable with a Km of 5-7 microM over a substrate range of 1-500 microM. A decrease in Na-dependent phosphate uptake in adult cells (30%) was found compared to that of young cells. The Na-independent component of phosphate uptake did not vary with age. In addition, the inhibition of phosphate uptake by a variety of compounds (ouabain, gramicidin, 2,4-dinitrophenol, KCN, and arsenate) were similar in both age groups. Kinetic analysis showed that a significant reduction in Vmax (4.4 +/- 0.4 vs. 3.1 +/- 0.2 nmol Pi/mg protein/10 min in young and adult cells, respectively), but not Km, resulted in this decreased uptake of phosphate in adult groups. There was no difference in the efflux of phosphate from both age groups. When cells were preincubated in a phosphate-free medium for 24 hours, the uptake of phosphate was increased to 46% and 24% of their corresponding controls in young and adult cells, respectively. The decreased phosphate uptake and limited adaptation to a phosphate-free medium by the adult renal cells may account for the hypophosphatemia and phosphaturia seen in adult and old animals in vivo.

Picogram quantitation of total DNA using DNA-binding proteins in a silicon sensor-based system

We report a rapid and reproducible method to quantify total DNA at picogram levels. Two high-affinity DNA-binding proteins are used to construct a sandwich assay and a semiconductor sensor is used for quantitation. Single-stranded DNA-binding protein (SSB) from Escherichia coli is conjugated with a linker molecule, biotin, for specific capture of the DNA complex onto a membrane. Monoclonal anti-DNA antibody is conjugated with an enzyme, urease, for signal generation. To detect DNA, a sample is denatured to form single-stranded DNA and then incubated with a reagent containing both DNA-binding protein conjugates and streptavidin. After incubation of the reagent with the DNA sample for 1 h at 37 degrees C to form a complex of streptavidin--biotin--SSB--DNA--anti-DNA--urease, the mixture is filtered through a biotin-coated nitrocellulose membrane which binds the streptavidin component of the complex. The unbound reagent is washed off the membrane, and then the captured DNA complex is detected with a light-addressable potentiometric sensor which measures the pH change catalyzed by the urease in the complex. This assay can detect 2 pg of DNA with a quantitation coefficient of variation of less than 10% in the range 10 to 200 pg.

The expression of integrated plasmid DNA depends on copy number

The effect of copy number, integration site, and enhancers on the expression of stably integrated exogenous DNA was examined in Chinese hamster cells. Three similar plasmids were constructed with the mouse beta maj-globin promoter fused to the galK gene either with no enhancer or with the SV40 or Harvey sarcoma virus (HaSV) enhancer. Eighteen stable cell lines were obtained and characterized with respect to plasmid copy number and galactokinase activity. At copy numbers of four or less, the enhancers showed detectable activity and a DNase I hypersensitive site was present. Above four copies, gene activity decreased as the copy number increased, the enhancer sequences were apparently inactive, and the DNase I hypersensitive site disappeared. These data suggest that, at least in this model system, when exogenous DNA is integrated as multiple head-to-tail copies, the entire multigene unit expresses poorly and inappropriately. When the same exogenous DNA integrates as a single (or low number) copy, expression appears to be relatively normal as judged by enhancer stimulation and DNase I hypersensitivity.