The Impact of Medicaid Expansion Under the Affordable Care Act on the Gap Between American Indians and Whites in Breast Cancer Management and Prognosis

BACKGROUND

Breast cancer (BC) death rates in the USA have not significantly declined for American Indians (AIs) in comparison to Whites. Our objective was to determine whether Medicaid Expansion as part of the Affordable Care Act led to improved BC outcomes for AIs relative to Whites.

PATIENTS AND METHODS

Using the National Cancer Database, we conducted a retrospective cohort study. Included were BC patients who were AI and White; 40 to 64 years of age; diagnosed in 2009 to 2016; lived in states that expanded Medicaid in January 2014, and states that did not expand Medicaid. Our outcomes were stage at diagnosis, insurance status, timely treatment, and 3-year mortality.

RESULTS

There were 359,484 newly diagnosed BC patients, 99.49% White, 0.51% AI. Uninsured rates declined more in the expansion states than in the nonexpansion states (OR = 0.44, 95% CI: 0.15-0.97, P < 0.001). Lower rates of Stage I BC diagnosis was found in AIs compared to Whites (46.58% vs. 55.33%, P < .001); these differential rates did not change after Medicaid expansion. Rates of definitive treatment initiation within 30 days of diagnosis declined after Medicaid expansion (P < .001); there was a smaller decline in the expansion states (OR 1.118, 95% CI: 1.09, 1.15, P < .001). Three year mortality was not different between expansion and nonexpansion states post Medicaid expansion.

CONCLUSIONS

In newly diagnosed BCs, uninsured rates declined more in the states that expanded Medicaid in January 2014. Timely treatment post Medicaid expansion declined less in states that expanded Medicaid. There was no differential benefit of Medicaid expansion in the 2 races.

Abstract P3-14-10: Breast cancer patterns, behavior and survival among American Indians in the west north central region and the other regions of the U.S

Purpose: American Indians (AIs) constitute the single largest racial minority in North Dakota and South Dakota. There are no studies looking at what sociodemographic or biological factors may play a role in affecting outcomes and mortality of breast cancer (BC) among AIs in the United States. Our study compared the BC patterns, behavior, and survival of AIs living in the West North Central Region (WNCR) of the U.S (which includes ND, SD, MN, NE, IO, KS, MO) to the AI BC patients in the remainder of the country. Methods: We used the records of all AI BC patients diagnosed between the years 2004-2016 from The National Cancer Database participant user files. All analyses were conducted using SPSS software (version 25). Results: Records were available for 6,466 AI BC patients, 798 were in the WNCR. There was no difference between WNCR and other regions in the stage distribution, mean age at diagnosis, morphology, hormonal/HER2 status, tumor size, lymph node status, or second cancers. The WNCR patients had less private insurance, lived in zip codes with lower median income, had more co-morbidities, and traveled longer distances for care (p&lt;0.001 for each). They had higher grade cancers (p&lt;0.001) at diagnosis. The WNCR patients were less likely to have received radiation therapy (p=0.015) but more likely to have received chemotherapy (p&lt;0.001) and hormonal therapy (p=0.009) and had longer inpatient stay days after surgery (p&lt;0.001). Time to first treatment and first treatment within 90 days (88.0% vs. 79.7%, p&lt;0.001) was significantly better in the WNCR than in other regions of the country. Five year mortality rate was higher (16.3% vs. 11.1%, p&lt;0.001) and cumulative survival was lower (p&lt;0.001) in the WNCR as compared to AIs in other regions of the country. Univariate/multivariate analysis failed to identify variables that could explain the differences in 5 year mortality or cumulative survival between WNCR and other regions. Conclusion:AIs with BC in the WNCR had worse 5 year mortality and cumulative survival as compared to AIs in other regions in the US. Our analysis could not identify variables that explained the differences in mortality or cumulative survival between WNCR and other regions.

Citation Format: Anu G Gaba, Li Cao, Rebecca Renfrew, Deann Witte, Janet Wernisch, Denise Lutkemeier, Kristi Egland, Ross Crosby. Breast cancer patterns, behavior and survival among American Indians in the west north central region and the other regions of the U.S. [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-14-10.

Inter-observer variability of the histological classification of lupus glomerulonephritis in children

The gold standard for the classification of lupus nephritis is renal histology but reporting variation exists. The aim of this study was to assess the inter-observer variability of the 2003 International Society of Nephrology/Royal Pathology Society (ISN/RPS) lupus nephritis histological classification criteria in children. Histopathologists from a reference centre and three tertiary paediatric centres independently reviewed digitalized renal histology slides from 55 children with lupus nephritis. Histological ISN/RPS Class was assigned and features scored; lupus nephritis-activity [scored 0-24], lupus nephritis-chronicity [0-12] and tubulointerstitial activity [0-21]. In the cohort (73% females), the age at the time of biopsy was 15.5 ± 0.39 (mean ± standard error) years. Based on the reference centre, 42% (23/55) had ISN/RPS Class IV with lupus nephritis-activity score 4.23 ± 0.50, lupus nephritis-chronicity 1.81 ± 0.18 and tubulointerstitial activity 4.45 ± 0.35. There were 4-54 (mean 16.7) glomeruli per biopsy. Pathologists had fair agreement for ISN/RPS assignment (kappa; 0.26 ± 0.12), lupus nephritis-chronicity (intra-class correlation 0.36 ± 0.09) and tubulointerstitial activity (0.22 ± 0.09) scores. There was good agreement for lupus nephritis-activity scores (intra-class correlation 0.69 ± 0.06). When categorized into proliferative and non-proliferative disease, poor agreement among sites remained (kappa 0.24 ± 0.11). Despite unified criteria for the interpretation of histological features of lupus nephritis, marked reporting variation remains in clinical practice. As proliferative lupus nephritis is managed more intensively, this may influence renal outcomes.

First Report of Race 2 of Colletotrichum trifolii Causing Anthracnose on Alfalfa (Medicago sativa) in Wisconsin

Anthracnose of alfalfa (Medicago sativa), caused by Colletotrichum trifolii, is widespread in the United States. In addition to loss of forage due to death of stems, the pathogen causes crown rot, reducing stand life and winter survival (2), making it one of the most serious diseases of alfalfa. Three physiological races have been described (2). Race 1 is reported to be the dominant race that is present wherever alfalfa is grown, while race 2 was reported in a limited area in the Mid-Atlantic states, and race 4 was found in Ohio (1). Conspicuous, straw-colored dead stems with a "shepherd's crook" wilt and large, sunken, diamond-shaped lesions with a dark border were observed in experimental plots and breeding nurseries of experimental lines in Clinton and West Salem, WI, in August 2011 and in West Salem, WI, in mid-August 2012. Acervuli with black setae and orange spore masses were observed in lesions placed in moist chambers for 2 days at room temperature with ambient room lighting. Conidia were germinated on 1% water agar and then single hyphae were transferred to potato dextrose agar (PDA) plates. DNA was extracted from pure cultures of strains DA-1 (Clinton, WI) and FGI-3 (West Salem, WI), the rDNA ITS1-5.8S-ITS2 region was amplified with primers ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3'), the products sequenced directly, and the sequences compared to the ITS region of known race 1 and race 2 strains of C. trifolii. The sequences from DA-1 and FGI-3 were identical to the ITS sequence of C. trifolii 2sp2 (race 1; KF444778) and C. trifolii SB-2 (race 2; KF444779), but distinct from the ITS sequence of C. destructivum (JQ005764) and C. dematium (JX567507), which can cause anthracnose on alfalfa (1). Conidia from DA-1 and FGI-3 were harvested from 7-day-old cultures grown on PDA plates, diluted to 2 × 10⁶ conidia/ml, and sprayed to runoff on 10-day-old growth chamber grown plants of three differential cultivars: Saranac (susceptible to races 1 and 2), Arc (resistant to race 1, susceptible to race 2), and Saranac AR (resistant to races 1 and 2). Plants were maintained at 100% relative humidity for 48 h and then grown in a growth chamber at 24°C with a 16-h photoperiod. Symptoms were rated at 14 days after inoculation. In the three repetitions of the experiment using 75 plants of each cultivar in each experiment, less than 10% of the Saranac and Arc plants survived, while survival of Saranac AR was 31 to 44%. The approximate expected survival of differential cultivars inoculated with race 1 is 1% for Saranac, 65 to 70% for Arc, and 45% for Saranac AR (2). Aggressiveness of race 2 strains on Saranac AR is variable, ranging from 12 to 68% plant survival (3). The susceptibility of Arc when inoculated with DA-1 and FGI-3 is consistent with the reaction to race 2 strains, indicating that both strains are race 2. The isolation of race 2 strains in major alfalfa growing regions in Wisconsin indicates that this physiological race is currently more widespread than previously observed. Although most modern alfalfa cultivars have resistance to race 1, few cultivars with resistance to race 2 are available. The occurrence of C. trifolii race 2 in the Midwest United States should be considered in alfalfa breeding programs when developing multi-pest resistant alfalfa cultivars. References: (1) J. J. Ariss and L. H. Rhodes. Plant Dis. 91:1362, 2007. (2) N. R. O'Neill. Plant Dis. 80:450, 1996. (3) N. R. O'Neill et al. Phytopathology 79:750, 1989.

Diabetes and cancer (1): evaluating the temporal relationship between type 2 diabetes and cancer incidence

Substantial evidence suggests that people with type 2 diabetes have an increased risk of developing several types of cancers. These associations may be due to a number of direct and indirect mechanisms. Observational studies of these associations, including the potential role for glucose-lowering therapy, are being increasingly reported, but face a number of methodological challenges. This paper is the first of two review papers addressing methodological aspects underpinning the interpretations of links between diabetes and cancer, and suggests potential approaches to study designs to be considered in observational studies. This paper reviews factors related to cancer incidence in the diabetic population; the second paper relates to studies of cancer mortality.

Accumulation and distribution of α-synuclein and ubiquitin in the CNS of Gaucher disease mouse models

Gaucher disease, a prevalent lysosomal storage disease, is caused by insufficient activity of acid β-glucosidase (GCase) and resultant glucosylceramide accumulation. Recently in Parkinson disease (PD) patients, heterozygous mutations in GCase have been associated with earlier onset and more progressive PD. To understand the pathogenic relationships between GCase variants and Parkinsonism, α-synuclein and ubiquitin distributions and levels in the brains of several mouse models containing GCase variants were evaluated by immunohistochemistry. Progressive α-synuclein and ubiquitin aggregate accumulations were observed in the cortex, hippocampus, basal ganglia, brainstem, and some cerebellar regions between 4 and 24 weeks in mice that were homozygous for GCase [D409H (9H) or V394L (4L)] variants and also had a prosaposin hypomorphic (PS-NA) transgene. In 4L/PS-NA and 9H/PS-NA mice, this was coincident with progressive neurological manifestations and brain glucosylceramide accumulation. Ultrastructural studies showed electron dense inclusion bodies in neurons and axons of 9H/PS-NA brains. α-synuclein aggregates were also observed in ventricular, brainstem, and cerebellar regions of older mice (>42-weeks) with the GCase variant (D409H/D409H) without overt neurological disease. In a chemically induced GCase deficiency, α-synuclein aggregates and glucosylceramide accumulation also occurred. These studies demonstrate a relationship between glucosylceramide accumulation and α-synuclein aggregates, and implicate glucosylceramide accumulation as risk factor for the α-synucleinopathies.

Subtractive gene expression profiling of articular cartilage and mesenchymal stem cells: serpins as cartilage-relevant differentiation markers

OBJECTIVE

Mesenchymal stem cells (MSCs) are a population of cells broadly discussed to support cartilage repair. The differentiation of MSCs into articular chondrocytes is, however, still poorly understood on the molecular level. The aim of this study was to perform an almost genome-wide screen for genes differentially expressed between cartilage and MSCs and to extract new markers useful to define chondrocyte differentiation stages.

METHODS

Gene expression profiles of MSCs (n=8) and articular cartilage from OA patients (n=7) were compared on a 30,000 cDNA-fragment array and differentially expressed genes were extracted by subtraction. Expression of selected genes was assessed during in vitro chondrogenic differentiation of MSCs and during dedifferentiation of expanded chondrocytes using quantitative and semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Protein secretion was measured by enzyme-linked immunosorbent assay.

RESULTS

Eighty-seven genes were differentially expressed between MSCs and cartilage with a more than three-fold difference. Sixty-seven of them were higher expressed in cartilage and among them 15 genes were previously not detected in cartilage. Differential expression was confirmed for 69% of 26 reanalysed genes by RT-PCR. The profiles of three unknown transcripts and six protease-related molecules were characterised during differentiation. SERPINA1 and SERPINA3 mRNA expression correlated with chondrogenic differentiation of MSCs and dedifferentiation of chondrocytes, and SERPINA1 protein levels in culture supernatants could be correlated alike.

CONCLUSIONS

cDNA-array analysis identified SERPINA1 and A3 as new differentiation-relevant genes for cartilage. Since SERPINA1 secretion correlated with both chondrogenesis of MSCs and dedifferentiation during chondrocyte expansion, it represents an attractive marker for refinement of chondrocyte differentiation.

Preoperative elevation of serum C--reactive protein is predictive for prognosis in myeloma bone disease after surgery

We investigated whether preoperative levels of serum C-reactive protein (CRP) and its correlation with tumour clinicopathological findings adds prognostic information beyond the time of diagnosis in patients with myeloma bone disease (MM) to facilitate the surgical decision-making process. Six hundred and fifty-eight myeloma patients were evaluated retrospectively for surgery. Clinicopathological variables of patients who underwent surgery (n=71) were compared between patients with preoperative CRP ⩾6 mg l⁻¹ and those with CRP <6 mg l⁻¹. Univariate and multivariate analyses were performed to identify prognostic factors after surgery. Patients with an increase of CRP prior to surgery showed inferior survival compared to patients with normal levels. Patients with normal CRP levels at diagnosis but elevations prior to surgery do seem to have a similar unfavourable overall survival (OS) than patients with an increase both, at diagnosis and at surgery. Conversely, patients with normal CRP levels prior to surgery still have the best OS, irrespective of their basic values. Multivariate analysis revealed preoperative CRP levels above 6 mg l⁻¹ Lactate dehydrogenase (LDH) above normal, and osteolyses in long weight bearing bones as independent predictors of survival. These findings suggest that in patients with MM serum levels of CRP increase during disease activity and might be significantly correlated with specific disease characteristics including adverse prognostic features such as osteolyses in long weight bearing bones. Thus, preoperative elevated CRP serum levels might be considered as independent predictor of prognosis and could provide additional prognostic information for the risk stratification before surgical treatment in patients with myeloma bone disease.

Acceptability of human papillomavirus self testing in female adolescents

OBJECTIVES

To develop scales assessing acceptability of human papillomavirus (HPV) testing in adolescents, to compare acceptability of self to clinician testing, and to identify adolescent characteristics associated with acceptability.

METHODS

Female adolescents 14-21 years of age attending a hospital based teen health centre self collected vaginal samples and a clinician, using a speculum, collected cervicovaginal samples for HPV DNA. Acceptability of and preferences for self and clinician testing were assessed at baseline and 2 week visits.

RESULTS

The mean age of the 121 participants was 17.8 years and 82% were black. The acceptability scales demonstrated good internal consistency, reliability, test-retest reliability, and factorial validity. Scores were significantly lower for self testing than clinician testing on the acceptability scale and three subscales measuring trust of the test result, confidence in one's ability to collect a specimen, and perceived effects of testing (p < 0.01). Of those who reported a preference, 73% preferred clinician to self testing. Acceptability scores for both self and clinician testing increased significantly pre-examination to post-examination (p < 0.01). Multivariable analyses demonstrated that race was independently associated with pre-examination and post-examination acceptability of self testing, and that sexual behaviours and gynaecological experiences were associated with specific acceptability subscales.

CONCLUSIONS

This sample of adolescents found clinician testing for HPV to be more acceptable than self testing and preferred clinician to self testing. If self testing for HPV is offered in the future, clinicians should not assume that adolescent patients will prefer self testing. Instead, they should educate adolescents about available testing options and discuss any concerns regarding self collection technique or accuracy of test results.

C5a is important in the tubulointerstitial component of experimental immune complex glomerulonephritis

Interstitial injury is the hallmark of glomerulonephritis which is progressing to end-stage renal disease (ESRD). In humans and experimental animals, we have shown that interstitial disease is accompanied by up-regulation of complement components in tubular epithelial cells. Glomerulonephritis was induced in mice by the intraperitoneal injection of horse spleen apoferritin (HSA) and lipopolysaccharide (LPS). In addition to wild-type C57/B6 mice, animals in which the C5a receptor had been deleted (C5aR KO) were used. Animals were killed after 3 or 6 weeks, and kidneys harvested. At three weeks, both groups had evidence of mild mesangial matrix expansion and increased cellularity; there were no crescents, sclerotic lesions, or interstitial disease. At six weeks, glomerular lesions were advanced, but identical in the two groups. Both groups had evidence of an identical pattern of C3 gene expression in the tubular epithelium by in situ hybridization. There was a marked difference, however, in the extent of interstitial injury. Wild-type animals had significantly greater numbers of infiltrating interstitial cells, greater expansion of the peritubular space, more tubular atrophy, and more apoptotic tubular cells than did C5aR KOs. The anaphylotoxic fragment of C5, C5a, is not likely to be important in the glomerular component of this model of progressive glomerulonephritis. On the other hand, the interstitial component is markedly attenuated in knockout animals. These data support a role for complement in the interstitial component of this glomerulonephritis model. They are consistent with our hypotheses of a role for complement in the progression of some forms of glomerulonephritis to ESRD.

Estrogen receptor beta is expressed in human colorectal adenocarcinoma

Estrogen receptor beta (ER-beta) has recently been detected in a human colon cancer cell line. The aim of this work was to determine whether ER-beta is expressed in human colorectal carcinoma (CRC) tissue and the extent of this expression. ER-beta expression in CRC was investigated by immunohistochemical staining of sections of formalin-fixed, paraffin-embedded tissue from 55 CRC. The percent of positive cells was recorded. ER-beta immunoreactivity was always present in normal epithelium and adenomas in the same sections of some CRC and was always nuclear. In CRC, nuclear ER-beta immunoreactivity was detected in >10% of the cancer cells in 67% of the cases and was almost always associated with cytoplasmic immunoreactivity. There were no statistically significant differences between the ER-beta-positive and -negative groups in regard to depth of invasion, nodal metastases, or survival, regardless of the cut-off value used. We conclude that (1) a significant number of CRCs are positive for ER-beta. (2) estrogen may play an important role in the proliferation of normal colonic epithelium, and (3) there is differential localization of ER-beta immunoreactivity between normal colon, adenomas, and CRCs. Whether different ER-beta isoforms are differentially expressed in CRCs, and whether human CRCs respond to treatment with antiestrogens, is the subject of studies currently in progress.

Evidence of a role for local complement expression in a murine model of progressive glomerulonephritis

C57/B6 mice received intraperitoneal horse spleen apoferritin (4 mg) with lipopolysaccharide (0.05 mg); control mice received 0.15 M NaCl. Control and treated animals were killed weekly for 6 wk; blood and urine specimens were obtained, and tissue samples were secured. Treated animals showed evidence of significant chronic disease, with proteinuria, hematuria, and uremia. A mild glomerulonephritis was present at 2 wk, with significant proliferative glomerulonephritis at 4 wk, progressing to chronic disease with tubulointerstitial changes at 6 wk. Changes at each time period were uniform between animals. C3 mRNA was first detected by in situ hybridization at 3 wk. Message was restricted to proximal tubular and periglomerular epithelial cells. Presence of C3 message preceded the development of interstitial inflammation and fibrosis by 1-2 wk, and its location and intensity paralleled the evolving interstitial disease. Although extensive mesangial C3 protein deposits appeared early, there was never C3 message in glomeruli or infiltrating cells. Before C3 message became apparent, two cytokines known to up-regulate C3 transcription in vitro, IL-1 and IL-6, were detected by immunohistochemistry. The temporal sequence in this model is consistent with our hypothesis that local synthesis and activation of C3 in tubular epithelium is important to the interstitial component of chronic glomerulonephritis. The process is independent of the deposition of circulating complement in the glomerulus, but may be triggered by glomerular cytokines.

Interventional catheter magnetic resonance angiography with a conventional 1.5-T magnet: work in progress

Magnetic resonance contrast enhancement depends on the relative timing of image acquisition. Limited human trials have demonstrated efficacy of intra-arterial gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) in delineating vascular anatomy with X-rays. The present study assessed the ability of dynamic MR during intra-arterial Gd-DTPA administration to demonstrate vascular anatomy compared to conventional angiography as the gold standard. As interventional MR techniques using dedicated magnets proliferate, the ability to perform invasive MR angiography with a conventional magnet would be of great utility at established sites. Four subjects referred for different types of angiography underwent dynamic MR studies, including one with iliac artery stenting (Palmaz P204, Johnson and Johnson). All were examined with conventional angiography, and again after dynamic intra-arterial (IA) Gd-DTPA infusion. Coronal MRI images of the body were acquired using a 1.5-T superconducting magnet (three with a GE Signa, one with Philips NT), fast spoiled gradient echo (FSPGR); echo time (TE) = 4.2 msec, repetition time (TR) = 68-150 msec, flip = 75 degrees, 0-600 s after dilute Gd-DTPA IA bolus injection during sequential breath-hold acquisitions of 13-32 s each. All arteries were detected with dynamic MR. The FSPGR MRI with IA Gd-DTPA administration can provide adequate time and spatial resolution to demonstrate arterial anatomy and arterial stent patency.

Targeted overexpression of parathyroid hormone-related protein (PTHrP) to vascular smooth muscle in transgenic mice lowers blood pressure and alters vascular contractility

PTH-related protein (PTHrP) and its receptor are expressed in vascular smooth muscle cells and are believed to participate in the local regulation of vascular tone. To explore the function of locally produced PTHrP in vascular smooth muscle in vivo, we developed transgenic mice that overexpress PTHrP in smooth muscle using a smooth muscle alpha-actin promoter to direct expression of the transgene. In the PTHrP-overexpressing mice, messenger RNA expression was mainly restricted to smooth muscle-containing tissues. Several founders also expressed the transgene in bone and heart and exhibited striking abnormalities in the development of these tissues. In PTHrP-overexpressing mice, blood pressure was significantly lower than that in wild-type controls (121 +/- 3 vs. 135 +/- 2 mm Hg; P < 0.01). Moreover, the magnitude of the vasorelaxant response to iv infusions of PTHrP-(1-34)NH2 was significantly attenuated in the transgenic animals. A similar desensitization to PTHrP was observed in aortic ring and portal vein preparations. Surprisingly, PTHrP-overexpressing mice were also significantly less responsive to the hypotensive action of infused acetylcholine in vivo and to the relaxant actions of acetylcholine on aortic vessel preparations in vitro. In summary, we have successfully targeted overexpression of PTHrP to the smooth muscle of transgenic mice. When expressed in its normal autocrine/paracrine setting, PTHrP lowers systemic blood pressure and decreases vascular responsiveness to further relaxation by PTHrP and other endothelium-dependent vasorelaxants such as acetylcholine. We postulate that the heterologous desensitization to acetylcholine-induced relaxation in PTHrP-overexpressing blood vessels involves desensitization of second messenger/effector signaling pathways common to PTHrP and acetylcholine.

Targeted disruption of the mouse lysosomal acid lipase gene: long-term survival with massive cholesteryl ester and triglyceride storage

Lysosomal acid lipase (LAL) is essential for the hydrolysis of the triglycerides and cholesteryl esters in lysosomes. Its deficiency produces two phenotypes, a severe infantile-onset variant, Wolman disease (WD), and a later onset variant, cholesteryl ester storage disease (CESD). A mouse model with a LAL null mutation was produced by targeting disruption of the mouse gene. Homozygote knockout mice (lal -/lal-) produce no LAL mRNA, protein or enzyme activity. The lal-/lal- mice are born in Mendelian ratios, are normal appearing at birth, and follow normal development into adulthood. However, massive accumulation of triglycerides and cholesteryl esters occurs in several organs. By 21 days, the liver develops a yellow-orange color and is approximately 1.5-2.0x larger than normal. The accumulated cholesteryl esters and triglycerides are approximately 30-fold greater than normal. The lal+/lal- mice have approximately 50% of normal LAL activity and do not show lipid accumulation. Male and female lal-/lal- mice are fertile and can be bred to produce progeny. This mouse model is a phenotypic model of human CESD, and a biochemical and histopathologic mimic of human WD. The lal-/lal- mice provide a model to determine the role of LAL in lipid metabolism and the pathogenesis of its deficiency states.

Dynamic gadolinium DTPA-enhanced magnetic resonance of intravascular stents

RATIONALE AND OBJECTIVES

Magnetic resonance contrast enhancement depends on the timing of image acquisition. Human trials have demonstrated efficacy of renal artery stents on salvage of renal function. This study assessed the ability of dynamic gadolinium (Gd)-DTPA administration to demonstrate renal and iliac artery stent patency compared to conventional angiography as the gold standard.

METHODS

Seven subjects with eight stents referred for angiography underwent dynamic magnetic resonance studies, all with renal artery stenting. All were examined with conventional angiography and after dynamic Gd-DTPA infusion. Coronal magnetic resonance images were acquired using a GE Signa 1.5 T magnet (fast spoiled gradient echo; echo time = 4.2 ms; repetition time = 68-150 ms; flip angle = 75 degrees) 0 to 600 seconds after 0.1 mmol/Kg Gd-DTPA intravenous bolus injection during sequential breath-hold acquisitions 13 to 32 seconds each.

RESULTS

All eight stents were visualized with 100% accurate patency documentation.

CONCLUSIONS

Fast spoiled gradient echo magnetic resonance imaging with bolus Gd-DTPA administration can provide adequate time and spatial resolution to demonstrate arterial stent patency.

Biological effects of targeted inactivation of hepatocyte growth factor-like protein in mice

Hepatocyte growth factor-like protein (HGFL) is a liver-derived serum glycoprotein involved in cell proliferation and differentiation, and is proposed to have a fundamental role in embryogenesis, fertility, hematopoiesis, macrophage activation, and tissue repair. To assess the in vivo effects of total loss of HGFL, we generated mice with targeted disruption of the gene resulting in loss of the protein. Disruption of the HGFL gene allowed for normal embryogenesis, and followed a Mendelian pattern of genetic transmission. Mice homozygous for the targeted allele (HGFL-/- mice) are fertile, and grow to adulthood without obvious phenotypic abnormalities in unchallenged animals, except for development of lipid-containing cytoplasmic vacuoles in hepatocytes throughout the liver lobules. These histologic changes are not accompanied by discernible changes in synthetic or excretory hepatic functions. Hematopoiesis appears unaltered, and although macrophage activation is delayed in the absence of HGFL, migration to the peritoneal cavity upon challenge with thioglycollate was similar in HGFL-/- and wild-type mice. Challenged with incision to skin, HGFL-/- mice display normal wound healing. These data demonstrate that HGFL is not essential for embryogenesis, fertility, or wound healing. HGFL-deficient mice will provide a valuable means to assess the role of HGFL in hepatic and systemic responses to inflammatory and infectious stimuli in vivo.

Standard dose Gd-DTPA dynamic MR of renal arteries

Renal MR contrast enhancement depends on the timing of image acquisition. Limited human trials have demonstrated efficacy of renal artery stents on salvage of renal function. This study assessed the ability of dynamic gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) administration to demonstrate renal artery stenosis and renal stent patency compared to conventional angiography as the gold standard. Twenty subjects referred for renal angiography underwent 22 dynamic MR studies, including 7 with renal artery stenting (Palmaz P204 or P201, Johnson & Johnson, Sydney, Australia). All were examined with conventional angiography and after dynamic Gd-DTPA infusion. Coronal MR images of the kidneys were acquired using a GE Signa 1.5-T magnet (General Electric Medical Systems, Milwaukee, WI) (fast spoiled gradient echo [FSPGR]; TE=4.2 msec, TR=68-150 msec, flip angle=75 degrees) 0 to 600 seconds after iv bolus injection of 15 ml of Gd-DTPA during sequential breath-hold acquisitions, 13 to 32 seconds each. All 51 renal arteries (13 stenosed, 38 normal) were detected with dynamic MRI. Severity of renal artery stenosis was classified correctly with an accuracy of 98% (95% confidence interval [CI]: 85-100), yielding 98% specificity and 100% sensitivity. All nine renal stents were visualized with 100% accurate patency documentation. FSPGR MRI with bolus Gd-DTPA administration can provide adequate time and spatial resolution to demonstrate renal artery stenosis.

Hereditary hemochromatosis. Preventing chronic effects of this underdiagnosed disorder

Hereditary hemochromatosis, once thought to be rare, is the most common genetic disorder in the United States. Nonetheless, the condition often goes undetected and untreated until its severe effects have become apparent. What clues can lead you to the diagnosis, and how can you spot them in your patients, before significant morbidity has occurred? In this article, Drs McDonnell and Witte discuss the diagnosis and management of this underrecognized problem as well as the various issues involved in screening. An illustrative case of hemochromatosis is also included.

Targeted overexpression of IGF-I evokes distinct patterns of organ remodeling in smooth muscle cell tissue beds of transgenic mice

Smooth muscle cells (SMC) of the vascular wall, bladder, myometrium, and gastrointestinal and respiratory tracts retain the ability to proliferate postnatally, which enables adaptive responses to injury, hormonal, or mechanical stimulation. SMC growth is regulated by a number of mesenchymal growth factors, including insulin-like growth factor I (IGF-I). To explore the function of IGF-I on SMC in vivo, the mouse SMC alpha-actin promoter fragment SMP8 (-1074 bp, 63 bp of 5'UT and 2.5 kb of intron 1) was cloned upstream of rat IGF-I cDNA, and the fusion gene microinjected to fertilized eggs of the FVB-N mouse strain. Mating of hemizygous mice with controls produced about 50% transgenic offspring, with equal sex distribution. Transgenic IGF-I mRNA expression was confined to SMC-containing tissues, with the following hierarchy: bladder > stomach > aorta = uterus > intestine. There was no transgene expression in skeletal muscle, heart, or liver. Radioimmunoassayable IGF-I content was increased by 3.5- to 4-fold in aorta, and by almost 10-fold in bladder of transgenic mice at 5 and 10 wk, with no change in plasma IGF-I levels. Wet weight of bladder, stomach, intestine, uterus, and aorta was selectively increased, with no change in total body or carcass weight of transgenic animals. In situ hybridization showed that transgene expression was exquisitely targeted to the smooth muscle layers of the arteries, veins, bladder, ureter, stomach, intestine, and uterus. Paracrine overproduction of IGF-I resulted in hyperplasia of the muscular layers of these tissues, manifesting in remarkably different phenotypes in the various SMC beds. Whereas the muscular layer of the bladder and stomach exhibited a concentric thickening, the SMC of the intestine and uterus grew in a longitudinal fashion, resulting in a marked lengthening of the small bowel and of the uterine horns. This report describes the first successful targeting of expression of any functional protein capable of modifying the phenotype of SMC in transgenic mice. IGF-I stimulates SMC hyperplasia, leading to distinct patterns of organ remodeling in the different tissue environments.

A submicroscopic deletion in Xq26 associated with familial situs ambiguus

Abnormal left-right-axis formation results in heterotaxy, a multiple-malformation syndrome often characterized by severe heart defects, splenic abnormalities, and gastrointestinal malrotation. Previously we had studied a large family in which a gene for heterotaxy, HTX1, was mapped to a 19-cM region in Xq24-q27.1. Further analysis of this family has revealed two recombinations that place HTX1 between DXS300 and DXS1062, an interval spanning approximately 1.3 Mb in Xq26.2. In order to provide independent confirmation of HTX1 localization, a PCR-based search for submicroscopic deletions in this region was performed in unrelated males with sporadic or familial heterotaxy. A cluster of sequence-tagged sites failed to amplify in an individual who also had a deceased, affected brother. FISH identified the mother as a carrier of the deletion, which arose as a new mutation from the maternal grandfather. The deletion interval spans 600-1,100 kb and lies wholly within the 1.3-Mb region identified by recombination. Discovery of this deletion supports localization of HTX1 to Xq26.2 and reveals the first molecular-genetic abnormality associated with human left-right-asymmetry defects.

Minor structural differences in Boc-CCK-4 derivatives dictate affinity and selectivity for CCK-A and CCK-B receptors

We previously reported novel Boc-CCK-4 (Boc-Trp-Met-Asp-Phe-NH2) derivatives possessing the general structure Boc-Trp-Lys[N epsilon-CO-NH-(R-Ph)]-Asp-Phe-NH2 (Shiosaki et al. J. Med. Chem. 1991, 34, 2837-2842). In contrast to Boc-CCK-4, which is 70-fold selective for the CCK-B receptor, the modified lysine-bearing tetrapeptides were highly potent and selective full agonists at the CCK-A receptor. Further investigation of the structure-activity profile following modification of the substituted phenylurea moiety appended off the lysine revealed that moving certain substituents, e.g. nitro or acetyl, from the 2- or 3-position on the phenyl ring to the 4-position, a relatively minor and subtle structural modification within the tetrapeptide, resulted in loss of CCK-A receptor selectivity and development of a trend toward CCK-B selectivity. These tetrapeptides, e.g. Boc-Trp-Lys[N epsilon-CO-NH-(4-NO2-Ph)]-Asp-Phe-NH2 and Boc-Trp-Lys[N epsilon-CO-NH-(4-Ac-Ph)]-Asp-Phe-NH2, were full agonists relative to CCK-8 in stimulating intracellular calcium mobilization in a cell line that expresses the CCK-B receptor.

Fibrolipomatous hamartoma: MR imaging findings

OBJECTIVE

To analyze the MR imaging features of fibrolipomatous hamartoma (FLH) of nerves.

DESIGN AND PATIENTS

MR imaging studies from six patients (three men and three women) were retrospectively reviewed by three musculoskeletal radiologists. In four patients, a biopsy of the nerve lesion was performed. In two patients, biopsy data were unavailable and the diagnosis was based on the clinical history combined with the MR imaging findings.

RESULTS AND CONCLUSION

MR imaging demonstrated fusiform nerve enlargement that was caused by fatty proliferation and thickening of nerve bundles. Nerve bundles appeared as serpentine tubular structures, hypointense on both T1- and T2-weighted images. The degree of fatty proliferation varied among patients. In addition, significant variation in the distribution of fat along the course of the nerves was noted. In three patients, FLH followed the branching pattern of the nerves, a characteristic pathologic finding. In two patients, intramuscular fat deposition (biceps and tibialis posterior muscles) was present. MR imaging findings of FLH are typical, allowing a confident diagnosis. The variation of fatty proliferation among patients and involved nerves as well as the tendency of the abnormalities to follow the branching pattern of the nerves is well demonstrated with MR imaging. FLH may present as an isolated nerve lesion, may be associated with intramuscular fat deposition, or may occur as a feature of macrodystrophia lipomatosa (MDL).

Immunohistological characteristics of T cell infiltrates in different forms of childhood onset chronic arthritis

OBJECTIVE

To characterize synovial T cell infiltrate, in terms of CD4/CD8 ratio and level of activation of T cells, in juvenile rheumatoid arthritis (JRA) and juvenile spondyloarthropathy(JSpA), to correlate these findings with clinical outcomes of the different forms of disease, and to compare them with findings in adult RA synovium.

METHODS

We studied synovial tissue specimens from 22 individuals with childhood onset of chronic arthritis (12 polyarticular JRA, 5 pauciarticular JRA, 5 JSpA) and 4 with adult RA. Specimens were selected from an initial bank from 40 patients on the basis of significant inflammation on hematoxylin and eosin and CD3 and CD68 monoclonal antibody staining (T cells and macrophages, respectively). Indirect immunohistochemistry was used with monoclonal antibodies to CD3, CD4, CD8, and interleukin 2 receptor alpha to determine CD4/CD8 ratios and the levels of activation within the T cell subsets. The distribution of gamma delta T cells was also studied.

RESULTS

Two patterns of T cell infiltration were seen. The majority of patients had lymphocytic aggregates associated with diffuse infiltrates; a few tissue specimens had diffuse infiltrates without aggregates. The CD4/CD8 ratio was significantly lower in pauciarticular course JRA than polyarticular JRA (p < 0.01) and RA (p < 0.05). Similarly patients with JSpA had a significantly lower CD4/CD8 ratio than patients with polyarticular JRA (P < 0.05). The level of T cell activation (CD3+IL-2R+) was significantly higher in pauciarticular compared with both polyarticular JRA (P < 0.01) and RA (p < 0.05). In general, higher levels of activation of CD8 cells than CD4 cells were seen, particularly in the pauciarticular JRA and JSpA groups. gamma delta T cells were prominent in 2 patients.

CONCLUSION

Demonstrated differences in T cell subset distribution between types of childhood chronic arthritis at a histopathological level may reflect different pathogenic mechanisms.

Regulated expression of complement factor B in the human kidney

We have previously demonstrated regulated expression of C3 in the proximal renal tubular epithelial cells of humans. To test the hypothesis that local alternative pathway complement activation could contribute to the tubulointerstitial component of chronic renal disease, we examined factor B gene expression in human kidneys. 35S riboprobes were generated from a human factor B cDNA. By in situ hybridization, proximal tubular factor B message was seen in 17 kidneys with various nephropathies. The expression was most intense in organs with evidence of interstitial inflammation, and its localization paralleled the inflammation. As was the case with C3 and C4, there was never any evidence of glomerular factor B message, nor was any seen in infiltrating inflammatory cells. In eight normal kidney tissues, factor B expression was either absent or restricted to rare foci of interstitial infiltration. The proximal renal tubular epithelium of humans appears to express the genes for both components of the alternative pathway convertase, C3 and factor B. These locally produced components may be important mediators of the interstitial inflammation that is common to all progressive nephritides.

[Results after coronary bypass operation]

OBJECTIVE

To determine the influence of various risk factors on 30-day postoperative mortality rate of aortocoronary bypass operation at different centres.

PATIENTS AND METHODS

Data on 227 patients (179 men, mean age 63 [40-87] years; 48 women, mean age 68 [44-81] years), 219 first operations, 8 second operations) were retrospectively analysed. In all patients the indications for aortocoronary bypass surgery had been established in the last 3 months of 1993. The operations had been performed at six cardiac centres in Germany (five in Hessen [H1-H5]) and in three hospitals elsewhere in Europe outside of Germany (E1-E3).

RESULTS

The operative mortality was relatively high (5.3%), 152 patients (67%) presenting with one or more risk factors accounting for an increased perioperative mortality. The mortality rate was significantly higher for: clearly impaired left ventricular function (ejection fraction < 40%): 20 vs 3% with an ejection fraction > or = 40% (P < 0.001); emergency operation: 16.6 vs 2.7% for elective operation (P < 0.001); advanced age (> or = 70 years): 10.9 vs 3.1% for younger patients (P < 0.025); and unstable angina: 9.2 vs 2.9% with stable angina (P < 0.05). Most of the bypasses were done with the internal mammary artery (63.9%, usually combined with venous bypasses (exclusive use of venous bypasses in 35.2%), but the proportion of arterial bypasses differed greatly between centres (96% in H3, 19% in H4).

CONCLUSIONS

(1) Aortocoronary bypass operations are done on many patients with important risk factors, resulting in a relatively high 30-day postoperative mortality rate. (2) The proportion of internal mammary artery bypasses markedly differs between centres in Hessen.

Turnover and distribution of intravenously administered mannose-terminated human acid beta-glucosidase in murine and human tissues

Gaucher disease type 1, the most prevalent lysosomal storage disease, is caused by the defective activity of the lysosomal enzyme, acid beta-glucosidase, or glucocerebrosidase. Infusion of purified acid beta-glucosidase containing alpha-mannosyl-terminated oligosaccharides (alglucerase) is efficacious in reversing hematologic, hepatic, splenic, and bony disease manifestations. The murine tissue distribution and turnover of bolus injections of alglucerase was evaluated by enzymatic activity, quantitative cross-reacting immunologic material analyses, and immunofluorescence studies. Enzyme activity measurements detected distribution to liver, spleen, thymus, kidney, and bone marrow mononuclear cells, but not to lungs and brain. In kidney and thymus, the enzyme was transiently present. In liver and spleen, enzyme activity peaked at about 20 min postinjection followed by a biphasic decrease with t1/2 approximately 40-60 min and approximately 12-14 h. In bone marrow maximal enzyme activity was at 40-60 min with a disappearance t1/2 approximately 60 min. Quantitative cross-reacting immunologic material studies of liver and spleen showed delivery of enzyme with decreased catalytic rate constants whose degradation included denaturation and proteolytic components. By immunofluorescence the human enzyme was distributed primarily to reticuloendothelial cells of the liver and spleen. In autopsy material from a Gaucher disease type 2 patient treated with enzyme, immunohistochemical and activity studies showed distributions similar to those in mice. These studies indicate a complex delivery and intracellular degradation of acid beta-glucosidase with lower intrinsic activity than the administered therapeutic agent.

ABT-431: the diacetyl prodrug of A-86929, a potent and selective dopamine D1 receptor agonist: in vitro characterization and effects in animal models of Parkinson's disease

(-)-Trans 9,10-hydroxy-2-propyl-4,5,5a,6,7,11b-hexahydro-3-thia-5- azacyclopent-1-ena[c]phenanthrene hydrochloride (A-86929) is a potent and selective full agonist at the dopamine (DA) D1-like receptor. Judging by its binding affinities to the D1 and D2 classes of receptors, the compound is approximately 20-fold D1 receptor-selective, whereas relative potencies based on functional in vitro assays indicate that A-86929 is greater than 400-fold D1-selective. A-86929 has moderate to weak (Ki > 1 microM) affinity at other monoaminergic and peptidergic receptors, at ion channels and at monoamine uptake sites. The catechol of A-86929 was bis-acetylated to produce the prodrug, (-)-trans 9,10-acetoxy-2-propyl-4,5,5a,6,7,11-b-hexahydro-3-thia- 5-azacyclopent-1-ena[c]phenanthrene hydrochloride (ABT-431), which is more chemically stable yet is rapidly converted to the parent compound with a half-life of less than 1 min in plasma. Both A-86929 and ABT-431 produced contralateral rotation in rats bearing unilateral 6-hydroxydopamine lesions, with ED50 values of 0.24 mumol/kg s.c. and 0.54 mumol/kg s.c., respectively. A-86929 and ABT-431 improved behavioral disability scores and increased locomotor activity in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned marmoset model of Parkinson's disease in a dose-dependent manner (the minimum effective dose was 0.10 mumol/kg s.c.). When administered three times daily for 30 consecutive days to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned marmosets, A-86929 significantly improved disability scores throughout the duration of the study. Current Parkinson's disease therapy includes L-dopa, which stimulates both classes of DA receptors by virtue of its conversion to DA in vivo, and direct-acting D2-selective agonists. Stimulation of the D2 receptor, which is associated with all current DA agonist-based therapies, may contribute to their dose-limiting side effects. An agent such as A-86929 (or its prodrug ABT-431), which selectively stimulates the D1 receptor, may represent a novel mechanism for Parkinson's disease therapy with the potential for an improved side-effect profile and, consequently, improved patient compliance.

Functional dichotomy of neutral and acidic sphingomyelinases in tumor necrosis factor signaling

Ceramide produced by sphingomyelinases (SMases) has been recognized as an important second messenger in growth factor receptor signaling. Tumor necrosis factor (TNF), through binding to the 55 kDa TNF receptor (TNF-R55), rapidly activates two distinct types of SMase, a membrane-associated neutral (N-)SMase, and an endosomal acidic (A)-SMase. N-SMase and A-SMase are activated independently by different cytoplasmic domains of TNF-R55. Each type of SMase specifically couples to select pathways of TNF signaling. Ceramide generated by N-SMase directs the activation of proline-directed serine/threonine protein kinase(s) and phospholipase A2. In contrast, A-SMase triggers the activation of NF-kappa B. No apparent crosstalk was detected between N-SMase and A-SMase pathways, indicating that ceramide action depends on the topology of its production. These results suggest that N-SMase and A-SMase control important yet dissociable and nonoverlapping pathways of TNF receptor signal transduction.

Expression of the neural intermediate filament proteins peripherin and neurofilament-66/alpha-internexin in neuroblastoma

BACKGROUND

Peripherin and neurofilament (NF)-66/alpha-internexin are recently characterized, neuron-specific intermediate filament proteins that are expressed in the developing peripheral nervous system. Peripherin, in particular, is highly enriched in neuronal derivatives of the neural crest. We speculated that these intermediate filament proteins would be expressed in neuroblastoma (NB), a neural crest-derived tumor with many neuronal features.

EXPERIMENTAL DESIGN

By use of antibodies specific to peripherin and NF-66/alpha-internexin, we detected these proteins on Western blots of NB tissue extracts and in paraffin sections of NBs.

RESULTS

Western blotting indicated that NB tumor extracts contained immunoreactive proteins that co-migrated with rat peripherin and human NF-66/alpha-internexin from normal tissues, thus establishing the specificity of the antibodies for these proteins in tumors. The antibody specific for peripherin labeled all NBs, including immature NBs, composite ganglioneuroblastomas and ganglioneuromas. In contrast, the NF-66/alpha-internexin antibody labeled only 50% of NBs, and only weakly labeled most ganglioneuroblastomas and ganglioneuromas. Neither antibody labeled other small blue cell tumors such as lymphomas, rhabdomyosarcomas, Wilms' tumors, and Ewing sarcomas.

CONCLUSIONS

The specificity of the peripherin labeling of NB and the ability of the peripherin antibody to label the entire spectrum of NBs, including ganglioneuroblastomas and ganglioneuromas, indicate that this intermediate filament protein has potential as a diagnostic marker for these related neural crest neoplasms.

Involvement of episomal hpv31 in a laryngeal carcinoma - persistent episomal maintenance of hpv DNA after passage through nude-mice

We describe the involvement of HPV31 in a laryngeal carcinoma, a highly unusual anatomic site for this HPV subtype. In situ hybridization with a type-specific HPV probe identified infected tumor cells. Diagnostic Southern blot analysis confirmed that the HPV was type 31, and also revealed that the HPV DNA was episomal. The tumor was passaged in nude mice, and analysis of HPV DNA in the passaged tumor revealed that the viral DNA had persisted and that it had remained episomal. The status of p53 in the tumor was examined by Southern blots and by PCR analysis of a closely linked, highly polymorphic dinucleotide repeat region. There was no apparent allele loss or loss of heterozygosity at p53 or at the locus of another putative tumor suppressor gene at 17p distal to p53. To assess the integrity of the p53 gene in more detail, exons 4 through 11 were amplified by PCR, and the amplified DNA was directly sequenced. No mutations in p53 were observed, suggesting that other mechanisms such as sequestration of p53 by the E6 or E7 products may have contributed to the malignancy.

Ossification of the Achilles tendon: imaging abnormalities in 12 patients

Ossification of the Achilles tendon is a rare clinical entity that is characterized by the presence of an ossific mass contained within the fibrocartilaginous substance of the tendon. Because the radiographic features of this condition have not been documented entirely and the magnetic resonance (MR) imaging findings have not been determined, a review of 16 affected tendons in 12 patients was performed in an attempt to characterize the imaging abnormalities associated with this process. MR imaging was performed in three Achilles tendons which demonstrated thickening of the tendons at the level of the ossifications and a lack of intratendinous signal abnormalities compatible with acute tendinitis. Signal intensity similar to that of bone marrow was present in the ossifications.

The relationship of human papillomaviruses to anorectal neoplasia

This review begins with an overview of the anatomy of the anal canal, which is followed by a discussion of human papillomavirus (HPV) infections in the anogenital tract. The organization of the HPV genome and the function of the encoded proteins is discussed in relation to the oncogenic potential of these viruses. Particularly stressed are interactions with known tumor suppressor genes. Then the interaction of HPV with the host cells and some growth factors is reviewed. An important consideration is the synergy between this virus and other known carcinogenic factors. These include smoking, immunologic status, and other factors. Finally, the pathologic features of anal warts and malignant lesions are summarized with respect to their histologic findings and expression of viral subtypes.

Cholecystokinin antagonists: (R)-tryptophan-based hybrid antagonists of high affinity and selectivity for CCK-A receptors

The intriguing structural similarities of glutamic acid based cholecystokinin (CCK) antagonists (A-64718 and A-65186) and the benzodiazepine CCK antagonist MK-329 (L-364,718) have been reported. Efforts to include the weak CCK antagonist benzotript into this construct utilizing a similar approach have resulted in a novel series of benzotript-based hybrid antagonists N alpha-(3'-quinolylcarbonyl)-(R)-tryptophan di-n-pentylamide (9, A-67396), N alpha-(4',8'-dihydroxy-2'-quinolylcarbonyl)-(R)-tryptophan di-n-pentylamide (23, A-70276), and N alpha-(3'-quinolylcarbonyl)-(R)-5'-hydroxytryptophan di-n-pentylamide (36, A-71134) which possess respectively binding affinities of 23, 21, and 11 nM for the pancreatic CCK-A receptor and which inhibit CCK8-induced amylase secretion. Compound 9 possesses a selectivity of greater than 500-fold for the pancreatic CCK-A receptor over the CCK-B receptor.

Distinct requirements for activation at CCK-A and CCK-B/gastrin receptors: studies with a C-terminal hydrazide analogue of cholecystokinin tetrapeptide (30-33)

We describe here the properties of tert-butyloxycarbonyl-Trp-Leu-Asp-Phe-NHNH2 (A-57696), a C-terminal hydrazide analogue of tert-butyloxycarbonyl-CCK4 (Boc-Trp-Met-Asp-Phe-NH2), at four cholecystokinin (CCK) receptor-bearing tissues, the guinea pig pancreas and gall bladder (Type A), guinea pig cortex (Type B), and NCI-H345 cells, a human small cell lung cancer cell line that expresses CCK-B/gastrin receptors. Using 125I-Bolton-Hunter-cholecystokinin octapeptide (26-33) (125I-Bolton-Hunter-CCK8) as the radioligand, A-57696 was found to be selective for cortical CCK-B receptors (IC50 = 25 nM), compared with pancreatic CCK-A receptors (IC50 = 15 microM). A-57696 behaved as a competitive antagonist in reversing CCK8-stimulated pancreatic amylase secretion and phosphoinositide breakdown. By Schild analysis, its Kd was determined to be 4.7 and 6.8 microM in amylase and phosphoinositide assays, respectively. A-57696 (100 microM) did not elicit gall bladder contraction, and it inhibited contractions induced by CCK8. The Kd of A-57696 at gall bladder CCK-A receptors was 19 microM. In contrast, A-57696 behaved as a partial agonist (80% of maximal CCK8 response) in stimulating calcium mobilization at CCK-B/gastrin receptors on NCI-H345 cells. A-57696 and CCK8 inhibited each other in calcium mobilization experiments utilizing the fluorescent dye Indo-1. Stimulatory actions of CCK8 and A-57696 were reversed by the CCK-B-selective (R)-L-365,260 (100 nM), whereas at the same concentration, the CCK-A-selective (S)-L-365,260 was ineffective. Binding studies using 125I-Bolton-Hunter-CCK8 and 125I-gastrin indicated that binding sites labeled by these two ligands displayed similar affinities for CCK8, desulfated CCK8, gastrin, A-57696, and both enantiomers of L-365,260. A-57696 represents a new class of CCK-A peptide antagonist at guinea pig pancreas a new class of CCK-A peptide antagonist at guinea pig pancreas and gall bladder. Its contrasting functional activities at guinea pig CCK-A and CCK-B/gastrin receptors in a human tumor cell demonstrate that, in addition to the previously described differences in binding specificity for selective agonists and antagonists, CCK-A receptors and CCK-B/gastrin receptors have different requirements for activation.

Evidence for a complex regulatory array in the first intron of the human adenosine deaminase gene

Adenosine deaminase (ADA) is expressed ubiquitously by diverse mammalian cells and tissues but at levels that vary according to tissue and species. In humans, the thymus exhibits levels of the enzyme up to 100-fold higher than most other tissues. Using transgenic mice, we identified human ADA gene regulatory domains. Up to 3.7 kb of 5'-flanking and first exon DNA from the human ADA gene failed to promote the expression of a chloramphenicol acetyl transferase (CAT) reporter gene in an efficient, reproducible, or tissue-appropriate manner in transgenic mice. However, when 12.8 kb of DNA from the first intron of the human ADA gene was placed 3' of CAT-coding and -processing sequences, transgenic mice reproducibly expressed CAT activity in most tissues, with profoundly high levels in the thymus. DNase I hypersensitivity studies demonstrated that among transgenic mouse tissues, human thymus, and a variety of human cell lines, a region of the intron 4-10 kb downstream of the first exon exhibited an array of hypersensitive sites that varied according to tissue and cell type. Deletion of this region from the gene construction eliminated high-level expression in transgenic mice. In transfection-transient expression assays, the 12.8-kb intron fragment exhibited enhancer activity in several cell types. A 1.3-kb fragment encompassing two of the hypersensitive sites exhibited some of these activities. The results of these studies suggest that the diverse pattern of human ADA gene expression is determined, in part, by a cluster of cis-regulatory elements contained within its large first intron.