Diet-induced obesity in mice impairs host defense against Klebsiella pneumonia in vivo and glucose transport and bactericidal functions in neutrophils in vitro

Obesity impairs host defense against Klebsiella pneumoniae, but responsible mechanisms are incompletely understood. To determine the impact of diet-induced obesity on pulmonary host defense against K. pneumoniae, we fed 6-wk-old male C57BL/6j mice a normal diet (ND) or high-fat diet (HFD) (13% vs. 60% fat, respectively) for 16 wk. Mice were intratracheally infected with Klebsiella, assayed at 24 or 48 h for bacterial colony-forming units, lung cytokines, and leukocytes from alveolar spaces, lung parenchyma, and gonadal adipose tissue were assessed using flow cytometry. Neutrophils from uninfected mice were cultured with and without 2-deoxy-d-glucose (2-DG) and assessed for phagocytosis, killing, reactive oxygen intermediates (ROI), transport of 2-DG, and glucose transporter (GLUT1-4) transcripts, and protein expression of GLUT1 and GLUT3. HFD mice had higher lung and splenic bacterial burdens. In HFD mice, baseline lung homogenate concentrations of IL-1β, IL-6, IL-17, IFN-γ, CXCL2, and TNF-α were reduced relative to ND mice, but following infection were greater for IL-6, CCL2, CXCL2, and IL-1β (24 h only). Despite equivalent lung homogenate leukocytes, HFD mice had fewer intraalveolar neutrophils. HFD neutrophils exhibited decreased Klebsiella phagocytosis and killing and reduced ROI to heat-killed Klebsiella in vitro. 2-DG transport was lower in HFD neutrophils, with reduced GLUT1 and GLUT3 transcripts and protein (GLUT3 only). Blocking glycolysis with 2-DG impaired bacterial killing and ROI production in neutrophils from mice fed ND but not HFD. Diet-induced obesity impairs pulmonary Klebsiella clearance and augments blood dissemination by reducing neutrophil killing and ROI due to impaired glucose transport.

Personality disorder and suicide risk among patients in the veterans affairs health system

Among veterans in Veterans Health Administration (VHA) care, patients with mental health and substance use conditions experience elevated suicide rates. However, despite previously demonstrated high rates of suicidal behavior, little is known regarding suicide rates among veteran VHA users with personality disorders (PDs) as a whole, or by PD clusters (A: Eccentric; B: Dramatic; C: Fearful; and PD-not otherwise specified). PD prevalence and suicide rates were assessed through 2017; overall and by clusters for 5,517,024 veterans alive as of 12/31/2013 and with more than 2 VHA encounters in 2012-2013. In all, 46,050 (.83%) had a PD diagnosis in 2012-2013. Suicide risk was examined using proportional hazards regressions adjusted for age, sex, veteran status, clustering within a geographic region, and other mental health diagnoses. Patients with PDs had greater suicide risk than those without (156.5 vs. 46.7 per 100,000 person-years). Individuals in Cluster B, which includes borderline and antisocial PDs, were at the highest risk (178.5 per 100,000 person-years), followed by PD-not otherwise specified and Cluster C (152.6 and 121.4 per 100,000 person-years, respectively). Rates of PDs in the VHA system were lower than those usually found in community samples. Veterans with a PD diagnosis had an increased risk of suicide, which was especially elevated for those with Cluster B diagnoses. Study findings document the importance of enhancing diagnosis and treatment for veterans with PDs and targeted suicide prevention services. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Hypertension Treatment Modality and Suicide Risk Among Veterans in Veterans Health Administration Care From 2015 to 2017

IMPORTANCE

The Veterans Health Administration (VHA) serves a population of veterans with a high prevalence of comorbid health conditions and increased risk for suicide.

OBJECTIVE

To replicate the findings of a previous study and assess whether exposure to angiotensin receptor blockers (ARBs) is associated with differential suicide risk compared with angiotensin-converting enzyme inhibitors (ACEIs) among veterans receiving VHA care.

DESIGN, SETTING, AND PARTICIPANTS

This nested case-control design included all suicide decedents from 2015 to 2017 with a VHA inpatient or outpatient encounter in the prior year and with either an active ACEI or ARB prescription in the 100 days prior to death. Using a 4:1 ratio, controls were matched to cases by age, sex, and hypertension and diabetes diagnoses. Controls were alive at the time of the death of the matched case, had a VHA encounter within the previous year, and had either an active ACEI or ARB medication fill within 100 days before the death of the matched case.

EXPOSURES

An active ACEI or ARB prescription within 100 days before the death of the case.

MAIN OUTCOMES AND MEASURES

Cases were suicide decedents from 2015 to 2017 per National Death Index search results included in the Veteran Affairs/Department of Defense Mortality Data Repository.

RESULTS

Among 1309 cases, the median (interquartile range [IQR]) age was 68 (60-76) years and among 5217 controls, the median (IQR) age was 67 (60-76) years, and 1.9% of veterans in both groups were female. ARBs were received by 20.2% of controls and 19.6% of cases; ACEIs were received by 79.8% of controls and 80.4% of cases. The crude suicide odds ratio for ARBs vs ACEIs was 0.966 (95% CI, 0.828-1.127). Controlling for covariates, the adjusted odds ratio for ARBs was 0.985 (95% CI, 0.834-1.164). Sensitivity analyses using only those covariates that differed significantly between groups, restricting to veterans ages 65 and older, dropping matching criteria, and adjusting for the quantity and temporal proximity of ACEI and ARB exposure in the 100 days prior to the index date, had consistent findings.

CONCLUSIONS AND RELEVANCE

This case-control study did not identify differences in suicide risk by receipt of ARBs vs ACEIs in analyses specific to veterans receiving VHA care in contrast with findings from the referent study.

Targeted pathologic evaluation of bone marrow donors identifies previously undiagnosed marrow abnormalities

Potential bone marrow donors are screened to ensure the safety of both the donor and recipient. At our institution, potential donors with abnormal peripheral blood cell counts, a personal history of malignancy, or age >60 years are evaluated to ensure that they are viable candidates for donation. Evaluation of the marrow includes morphologic, flow cytometric, and cytogenetic studies. A total of 122 potential donors were screened between the years of 2001 and 2011, encompassing approximately 10% of all donors. Of the screened potential donors, the mean age was 59 years and there were 59 men and 63 women. The donors were screened because of age >60 years (n = 33), anemia (n = 22), cytopenias other than anemia (n = 27), elevated peripheral blood counts without a concurrent cytopenia (n = 20), elevated peripheral blood counts with a concurrent cytopenia (n = 10), history of malignancy (n = 4), abnormal peripheral blood differential (n = 3), prior graft failure (n = 1), history of treatment with chemotherapy (n = 1), and body habitus (n = 1). Marrow abnormalities were detected in 9% (11 of 122) of donors. These donors were screened because of anemia (5 of 22, 23%), age >60 years (2 of 33, 6%), history of malignancy (2 of 4, 50%), elevated peripheral blood counts (1 of 20, 5%), and body habitus (1 of 1, 100%). Abnormalities included plasma cell dyscrasia (n = 3), abnormal marrow cellularity (n = 3), clonal cytogenetic abnormalities (n = 2), low-grade myelodysplastic syndrome (1), a mutated JAK2 V617F allele (n = 1), and monoclonal B cell lymphocytosis (n = 1). Our experience indicates that extended screening of potential donors identifies a significant number of donors with previously undiagnosed marrow abnormalities.

Molecular cytogenetic characterization of pancreas cancer cell lines reveals high complexity chromosomal alterations

Karyotype analysis can provide clues to significant genes involved in the genesis and growth of pancreas cancer. The genome of pancreas cancer is complex, and G-band analysis cannot resolve many of the karyotypic abnormalities seen. We studied the karyotypes of 15 recently established cell lines using molecular cytogenetic tools. Comparative genomic hybridization (CGH) analysis of all 15 lines identified genomic gains of 3q, 8q, 11q, 17q, and chromosome 20 in nine or more cell lines. CGH confirmed frequent loss of chromosome 18, 17p, 6q, and 8p. 14/15 cell lines demonstrated loss of chromosome 18q, either by loss of a copy of chromosome 18 (n = 5), all of 18q (n = 7) or portions of 18q (n = 2). Multicolor FISH (Spectral Karyotyping, or SKY) of 11 lines identified many complex structural chromosomal aberrations. 93 structurally abnormal chromosomes were evaluated, for which SKY added new information to 67. Several potentially site-specific recurrent rearrangements were observed. Chromosome region 18q11.2 was recurrently involved in nine cell lines, including formation of derivative chromosomes 18 from a t(18;22) (three cell lines), t(17;18) (two cell lines), and t(12;18), t(15;18), t(18;20), and ins(6;18) (one cell line each). To further define the breakpoints involved on chromosome 18, YACs from the 18q11.2 region, spanning approximately 8 Mb, were used to perform targeted FISH analyses of these lines. We found significant heterogeneity in the breakpoints despite their G-band similarity, including multiple independent regions of loss proximal to the already identified loss of DPC4 at 18q21.

Acute bilineal leukemia: a rare disease with poor outcome

Most cases of acute leukemia can be assigned to the myeloid, B or T lineage. In a few cases, definitive assignment cannot be achieved because blasts express antigens of more than one lineage. A subset of these, referred to as acute bilineal leukemias (aBLLs), is characterized by the presence of more than one population of blasts, each comprising a single lineage. We identified 19 cases of aBLL, including 10 mixed T and myeloid (T-My) and nine mixed B and myeloid (B-My); no mixed B and T cases were identified. Cytogenetic data were available for 16 patients. Three of seven patients with B-My had a t(9;22)(q34q11.2), two had 11q23 translocations and one had del(9). Two of nine patients with T-My had 2p13 translocations; five had other unrelated abnormalities. Of 16 patients with outcome data, only six achieved complete remission and only two remain free of disease 2.5 and 4.5 years after chemotherapy or stem cell transplantation. aBLL is a rare disease that combines B or T and myeloid blasts. Cytogenetic abnormalities of t(9;22) and 11q23 are common in, and may be restricted to, B-My cases, while T-My cases have frequent but generally non-recurring abnormalities. Both types of aBLL are associated with poor outcome.

Assessment of the use and feasibility of video to supplement the genetic counseling process: a cancer genetic counseling perspective

Cancer genetic counselors use a variety of teaching modalities for patient education. This survey of cancer genetic counselors assessed their use of educational videos and their recommendations for content of future videos. Thirty percent of respondents use videos for patient education. Cited benefits included reinforcement of information for clients and increased counselor efficiency. Of the 70% who do not use videos, predominant barriers included the perceived lack of an appropriate video, lack of space and/or equipment, and concern that videos are impersonal. Most respondents desired a video that is representative of the genetic counseling session, but emphasized the importance of using broad information. Content considered critical included the pros and cons of genetic testing, associated psychosocial implications, and genetic discrimination. The results of this exploratory study provide data relevant for the development of a cancer genetics video for patient education, and suggestions are made based on aspects of information processing and communication theories.

Facial dysgenesis: a novel facial syndrome with chromosome 7 deletion p15.1-21.1

We describe a female neonate with a unique constellation of features including anophthalmia and cryptophthalmos, temporal remnant "eye tags," bilateral cleft lip, unilateral cleft palate, a proboscis with absent nasal septum, choanal atresia, micrognathia, square stoma, and bilateral external auditory canal atresia. Gross brain structure, pituitary function, limbs, trunk, and genitalia were normal. Skeletal survey, echocardiogram and abdominal viscera were unremarkable except for a split central sinus of the right kidney. BAER exam indicated she could hear and temporal CT confirmed the presence of cochlea and possible ossicles. Cytogenetic evaluation revealed an interstitial deletion at chromosome 7p15.1-21.1. TWIST, a gene encoding a transcription factor involved in craniofacial development, is deleted by FISH analysis. The absence of a mutation on the non-deleted allele of TWIST as determined by sequencing virtually eliminates complete loss of the TWIST gene as the cause of this patient's severe phenotype. The HOXA gene cluster also encodes transcription factors that are crucial for directing cephalad to caudad somatic fetal development. HOXA1, the most telomeric of the 13 members of the HOXA gene cluster, is located at the centromeric boundary of the patient's chromosome 7 deletion. By FISH analysis, neither allele of HOXA1 is deleted and sequencing reveals no mutations. Haploinsufficiency or complete loss of the HOXA1 gene also does not appear to cause this patient's severe phenotype. Previous reports of chromosome 7p15-21 deletions do not have phenotypes similar to this patient.

A novel c-Myc-responsive gene, JPO1, participates in neoplastic transformation

We have identified a novel c-Myc-responsive gene, named JPO1, by representational difference analysis. JPO1 responds to two inducible c-Myc systems and behaves as a direct c-Myc target gene. JPO1 mRNA expression is readily detectable in the thymus, small intestine, and colon, whereas expression is relatively low in spleen, bone marrow, and peripheral leukocytes. We cloned a full-length JPO1 cDNA that encodes a 47-kDa nuclear protein. To determine the role of JPO1 in Myc-mediated cellular phenotypes, stable Rat1a fibroblasts overexpressing JPO1 were tested and compared with transformed Rat1a-Myc cells. Although JPO1 has a diminished transforming activity as compared with c-Myc, JPO1 complements a transformation-defective Myc Box II mutant in the Rat1a transformation assay. This complementation provides evidence for a genetic link between c-Myc and JPO1. Similar to c-Myc, JPO1 overexpression enhances the clonogenicity of CB33 human lymphoblastoid cells in methylcellulose assays. These observations suggest that JPO1 participates in c-Myc-mediated transformation, supporting an emerging concept that c-Myc target genes constitute nodal points in a network of pathways that lead from c-Myc to various Myc-related phenotypes and ultimately to tumorigenesis.

Arsenic inhibition of telomerase transcription leads to genetic instability

Arsenic is effective in the treatment of acute promyelocytic leukemia. Paradoxically, it is also carcinogenic. In the process of elucidating a mechanism of arsenic resistance in a leukemia cell line, NB4, we discovered that arsenic exposure causes chromosomal abnormalities, with a preponderance of end-to-end fusions. These chromosomal end fusions suggested that telomerase activity may be inhibited by arsenic. We found that arsenic inhibits transcription of the hTERT gene, which encodes the reverse transcriptase subunit of human telomerase. This effect may in part be explained by decreased c-Myc and Sp1 transcription factor activities. Decreased telomerase activity leads to chromosomal end lesions, which promote either genomic instability and carcinogenesis or cancer cell death. These phenomena may explain the seemingly paradoxical carcinogenic and antitumor effects of arsenic.

Impact of the putative differentiating agent sodium phenylbutyrate on myelodysplastic syndromes and acute myeloid leukemia

Sodium phenylbutyrate (PB) is an aromatic fatty acid with cytostatic and differentiating activity against malignant myeloid cells (ID(50), 1-2 mM). Higher doses induce apoptosis. Patients with myelodysplasia (n = 11) and acute myeloid leukemia (n = 16) were treated with PB as a 7-day continuous infusion repeated every 28 days in a Phase I dose escalation study. The maximum tolerated dose was 375 mg/kg/day; higher doses led to dose-limiting reversible neurocortical toxicity. At the maximum tolerated dose, PB was extremely well tolerated, with no significant toxicities; median steady-state plasma concentration at this dose was 0.29 +/- 0.16 mM. Although no patients achieved complete or partial remission, four patients achieved hematological improvement (neutrophils in three, platelet transfusion-independence in one). Other patients developed transient increases in neutrophils or platelets and decrements in circulating blasts. Monitoring of the percentage of clonal cells using centromere fluorescence in situ hybridization over the course of PB administration showed that hematopoiesis remained clonal. Hematological response was often associated with increases in both colony-forming units-granulocyte-macrophage and leukemic colony-forming units. PB administration was also associated with increases in fetal erythrocytes. These data document the safety of continuous infusion PB and provide preliminary evidence of clinical activity in patients with myeloid malignancies.

Effects of mixed hematopoietic chimerism in a mouse model of bone marrow transplantation for sickle cell anemia

Sickle cell anemia (SCA) is an inherited disorder of beta-globin, resulting in red blood cell rigidity, anemia, painful crises, organ infarctions, and reduced life expectancy. Allogeneic blood or marrow transplantation (BMT) can cure SCA but is associated with an 8% to 10% mortality rate, primarily from complications of marrow-ablative conditioning. Transplantation of allogeneic marrow after less intensive conditioning reduces toxicity but may result in stable mixed hematopoietic chimerism. The few SCA patients who inadvertently developed mixed chimerism after BMT remain symptom free, suggesting that mixed chimerism can reduce disease-related morbidity. However, because the effects of various levels of mixed chimerism on organ pathology have not been characterized, this study examined the histologic effects of an increasing percentage of normal donor hematopoiesis in a mouse model of BMT for SCA. In lethally irradiated normal mice that were reconstituted with varying ratios of T-cell-depleted marrow from normal and transgenic "sickle cell" mice, normal myeloid chimerism in excess of 25% was associated with more than 90% normal hemoglobin (Hb). However, 70% normal myeloid chimerism was required to reverse the anemia. Organ pathology, including liver infarction, was present in mice with sickle Hb (HbS) levels as low as 16.8% (19.6% normal myeloid chimerism). Histologic abnormalities increased in severity up to 80% HbS, but were less severe in mice with more than 80% HbS than in those with 40% to 80% HbS. Therefore, stable mixed chimerism resulting from nonmyeloablative BMT may reduce the morbidity from SCA, but prevention of all disease complications may require minimizing the fraction of circulating sickle red cells. (Blood. 2001;97:3960-3965)

A distinctive pediatric renal neoplasm characterized by epithelioid morphology, basement membrane production, focal HMB45 immunoreactivity, and t(6;11)(p21.1;q12) chromosome translocation

We report two cases of a hitherto undescribed pediatric renal neoplasm that is distinctive at the morphological, immunohistochemical, ultrastructural, and cytogenetic levels. On light microscopy, the tumors are composed of nests of polygonal, clear to eosinophilic cells associated with a subpopulation of smaller cells that surround hyaline material. Despite their epithelioid morphology, these tumors do not label immunohistochemically for epithelial markers but instead label focally for melanocytic markers HMB45 and Melan A. The hyaline material is positive with periodic acid-Schiff and methenamine-silver histochemical stains, and labels immunohistochemically for type 4 collagen. Ultrastructural examination confirms that it represents basement membrane material. Cytogenetic analysis reveals the identical t(6;11)(p21.1;q12) chromosome translocation as the sole abnormality in these two tumors, confirming their identity and distinctive nature.

ALK1 and p80 expression and chromosomal rearrangements involving 2p23 in inflammatory myofibroblastic tumor

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is an uncommon tumor of extrapulmonary and pulmonary tissues with an unpredictable clinical course, occasional recurrences, and rare malignant transformation. Clonal abnormalities with rearrangements of chromosome of 2p23 and the ALK gene have been reported in a few cases. The purpose of this study is to investigate whether these are consistent abnormalities among IMTs or represent a distinct subset.

DESIGN

Formalin-fixed, paraffin-embedded archival tissue sections from 47 IMTs in 40 patients were immunostained with monoclonal antibodies against ALK and p80. Fluorescence in situ hybridization for ALK rearrangements was done on 22 IMTs from 19 patients. Findings were correlated with clinical features and outcome.

RESULTS

ALK positivity was observed in 17 of 47 IMTs (36%) and p80 positivity in 16 of 47 IMTs (34%). Fluorescence in situ hybridization showed ALK rearrangements in nine cases (47%), aneuploidy in three cases (16%), and no rearrangement in seven cases (37%). IMTs with ALK abnormalities by immunohistochemistry and/or fluorescence in situ hybridization originated in the abdomen/pelvis/retroperitoneum, chest, and extremities. The mean age was 6.6 years, with a male/female ratio of 1.3. 64% of patients had no evidence of disease at last follow-up, 45% had one or more recurrences, and 18% displayed histologic evidence of malignant transformation. The IMTs without ALK abnormalities occurred in older children, were more frequent in females, and had fewer recurrences. However, in this group of 40 patients, the differences between the groups with and without ALK abnormalities did not have statistical significance. Aneuploidy without ALK abnormalities was associated with malignant transformation in three of five cases.

CONCLUSIONS

Abnormalities of ALK and p80 and evidence of chromosomal rearrangements of 2p23 occur in a significant proportion of IMTs. These changes are most frequent in abdominal and pulmonary IMTs in the first decade of life and are associated with a higher frequency of recurrence. These findings confirm the neoplastic nature of a subset IMT with ALK abnormalities and suggest that aneuploid IMT is a subset with more aggressive clinical behavior.

ALK probe rearrangement in a t(2;11;2)(p23;p15;q31) translocation found in a prenatal myofibroblastic fibrous lesion: toward a molecular definition of an inflammatory myofibroblastic tumor family?

A prenatal tumor located in the lumbar paravertebral area was discovered during a routine ultrasound examination at 32 weeks of pregnancy and surgically removed at 4 months of life. The histopathological diagnosis was first suggested to be an infantile desmoid fibromatosis. The tumor karyotype showed a three-way translocation involving both chromosomes 2 and a chromosome 11, t(2;11;2)(p23;p15;q31). Fluorescence in situ hybridization with a probe flanking the ALK gene at 2p23 demonstrated a rearrangement, as previously described in inflammatory myofibroblastic tumors (IMTs). In light of the genetic analysis, the histopathological diagnosis was revised to IMT, although inflammatory cells were scarce. IMTs are pseudosarcomatous inflammatory lesions that primarily occur in the soft tissue and viscera of children and young adults. Our report describes for the first time the occurrence of IMT during prenatal life. The ALK rearrangement may represent the molecular definition of a subgroup of mesenchymal tumors, not always with complete morphological features of IMT, similar to the model of EWS rearrangement in the Ewing sarcoma family of tumors.

Primary cutaneous T-cell-rich B-cell lymphoma: clinically distinct from its nodal counterpart?

The cases of two patients with Stage IE primary cutaneous T-cell-rich B-cell lymphoma (TCRBCL) are described. In both, the lesion showed a dense infiltrate by numerous small T lymphocytes with scattered histiocytes and large atypical B-lymphoid cells. Polymerase chain reaction assays demonstrated that the B cells were monoclonal, with immunoglobulin heavy-chain gene rearrangement. No clonal rearrangements of the T-cell receptor gamma gene were observed. Both patients were disease-free at 4 months and at 5 years after therapy, respectively. Although rare, primary cutaneous T-cell-rich B-cell lymphoma appears to have a better prognosis than its nodal counterpart, with or without skin involvement.

Use of single nucleotide polymorphisms (SNP) and real-time polymerase chain reaction for bone marrow engraftment analysis

Allogeneic bone marrow transplant engraftment assays use polymorphisms in the human genome to determine the relative percentages of donor and recipient cells present in the recipient. We describe a novel posttransplant assay approach using single nucleotide polymorphisms (SNPs), the most common type of polymorphism in humans. Using samples of defined genotype, we used real-time polymerase chain reaction (PCR) and allele-specific fluorescent TaqMan probes to assay a SNP of the cytochrome P450 CYP2C9 gene. Standard curves of chimeric mixes showed a linear relationship between the ratio of two alleles and the ratio of their respective fluorophore emission, except for mixes with a low percentage (< 5%) of the less common allele. We validated the SNP real-time PCR assay by comparing it to Southern hybridization analysis, analyzing DNA mixes in a blinded fashion with both methods. The correlation between the two methods was high. We have produced a statistical model that varies allele frequency to predict how many SNPs would be required to produce a functional SNP panel. Additional development will be necessary to produce such a panel of highly informative SNPs for clinical use. A real-time PCR SNP assay may ultimately provide more accurate quantification and shortened turnaround time compared to current post-engraftment assays.

A new primary effusion lymphoma-derived cell line yields a highly infectious Kaposi's sarcoma herpesvirus-containing supernatant

A primary effusion lymphoma (PEL) cell line, JSC-1, that yields highly infectious Kaposi's sarcoma herpesvirus (KSHV) supernatants was established from the ascitic fluid of a human immunodeficiency virus-positive patient. Flow cytometry showed strong expression of CD45 and lambda light-chain restriction. Southern blot hybridization showed immunoglobulin heavy-chain gene rearrangements in the tumor and the resultant cell line consistent with B-cell lineage. Expression of viral genes was assessed by reverse transcription-PCR and immunohistochemistry. Only latent Epstein-Barr virus (EBV) gene expression was detected, and this was at a low level. In contrast, lytic and latent KSHV gene expression were detected. Tetradecanoyl phorbol acetate and butyrate upregulated KSHV lytic expression, but not EBV lytic expression. Viral supernatant from JSC-1 was much more efficient at infecting primary human dermal microvascular endothelial cells (DMVECs) with KSHV than supernatants from BC-3 or BCP-1 PEL cell lines. Quantitation of viral yields produced by the PEL lines showed at least 2 orders of magnitude more DNase I-resistant KSHV DNA in the JSC-1 supernatant compared to BC-3 or BCP-1 supernatants. KSHV infection in DMVECs was associated with a change from a cobblestone to a spindle shape, LANA expression, and an increased number of mitoses.

Pseudo-spikes are common in histologically benign lymphoid tissues

T cell receptor gene rearrangement is a classic marker of T cell clonality and is a useful adjunct in the diagnosis of T cell lymphomas and leukemias. Rearranged V-J gene segments amplified by polymerase chain reaction (PCR) are traditionally analyzed by polyacrylamide gel electrophoresis. We and others have analyzed TCR-gamma PCR products using capillary gel electrophoresis, which produces single nucleotide resolution and provides improved diagnostic sensitivity over conventional methods. However, with this marked increase in resolution and sensitivity, it is necessary to re-define normal variation of TCR-gamma gene rearrangement in control tissues to allow appropriate interpretation of monoclonality if present. Using DNA capillary gel electrophoresis, we examined the spectrum of normal patterns for TCR-gamma in a variety of T-cell-rich, histologically benign tissue types, including spleen, lymph node, tonsil, and blood, and compared this with the patterns in T cell lymphoma samples. We defined relative peak heights as h1/h2, where h1 represents the peak height of the largest peak above the normally distributed population, and h2 represents the peak height of the normally distributed curve. We found spikes in almost 20% of histologically benign samples with relative peak heights that were more than 0.5 and up to 1.5. We designated these as pseudo-spikes, because they may be mistaken for monoclonal spikes. In contrast, the relative peak height of the T cell lymphoma samples that showed clonal rearrangement was much higher than that of the pseudo-spikes, being at least 2 in 11/11 and at least 3 in 10/11 cases. Our data suggest that peaks with relative height of at least 3 represent a true clonal population in diagnostic samples. Peaks with relative heights of less than 1.5 may be insignificant, while peaks with relative heights between 1.5 to 3 may warrant further evaluation. Although capillary gel electrophoresis is superior in assessing T cell clonality, caution must be exercised when interpreting results, because pseudo-spikes appear to be common in benign tissues with lymphoid populations and are not necessarily indicative of clonal malignant T cell population.

The tissue renin-angiotensin system in rats with fructose-induced hypertension: overexpression of type 1 angiotensin II receptor in adipose tissue

OBJECTIVE

Fructose feeding induces hypertension, insulin-resistance and hypertriglyceridemia in Sprague-Dawley rats. The mechanisms of fructose-induced hypertension are as yet unknown. Here we investigate the effects of fructose feeding and of varying salt intake on blood pressure, glucose tolerance, plasma renin activity, and tissue angiotensinogen, renin, and AT1 receptor mRNA levels in this model of hypertension.

DESIGN AND METHODS

To investigate the role of the renin-angiotensin system in fructose-induced hypertension we measured angiotensinogen, renin and angiotensin II type 1 (AT1) receptor mRNA levels in tissues of Sprague-Dawley rats that were fed either standard rat chow or a diet containing 66% fructose.

RESULTS

Blood pressure (P < 0.05) and triglyceride (P < 0.01) levels were significantly greater in the fructose-fed animals. Plasma glucose and insulin responses to an oral glucose load were significantly greater (P< 0.05) in fructose-fed than control rats. Angiotensinogen mRNA levels in liver and fat, and renin mRNA levels in kidney did not differ between fructose-fed and control animals. Levels of AT1 receptor mRNA were significantly greater in the fat obtained from fructose-fed rats than in that from control rats (P< 0.05), but this was not so in the kidney. To determine whether fructose-induced hypertension is dependent on dietary salt content, rats were fed standard rat chow and a fructose-enriched diet with low and high sodium chloride concentrations. Blood pressure increased significantly (P< 0.05) only in the fructose-fed rats receiving the high-salt diet Similarly, increased AT1 receptor mRNA levels were observed only in the fructose-fed rats that were maintained on the high-salt diet

CONCLUSIONS

Fructose feeding induces hypertension in normal- or high-salt fed animals and it is associated with an increased expression of the AT1 receptor in adipose tissue. These findings suggest that AT1 receptors might play a role in the pathophysiology of metabolic and hemodynamic abnormalities induced by fructose feeding.

Response to genetic counseling and testing for the APC I1307K mutation

The APC I1307K gene mutation is associated with increased colorectal cancer (CRC) risk in Ashkenazi Jews. Factors predicting acceptance of this and other hereditary colon cancer mutation tests in a clinical setting are unknown. We analyzed sex, age, family history, personal history, and gene test results of patients at increased risk for cancer who sought cancer risk counseling at the Johns Hopkins (JH) CRC Risk Assessment Clinic (n = 91), and those submitting samples to the JH Pathology Molecular Diagnostic Laboratory (n = 256) for APC I1307K testing. Of patients seen at the JH Clinic, 77/91 (84.6%) elected APC I1307K testing after pretest counseling (acceptors). There were no statistically significant differences in demographic characteristics between acceptors and decliners. In comparison, only 8 of 57 (14.0%) patients offered HNPCC testing proceeded with testing (P < 0.001). Of 256 individuals tested at the JH laboratory, most were male (61.3%) and most had a personal or family history of colorectal cancer or polyps. Test positivity correlated with increasing risk of colorectal cancer. Acceptance of testing for the APC I1307K mutation is high, with more men than women pursuing counseling and testing. The reported association between the APC I1307K mutation and colon cancer risk was supported by a correlation in these data between personal or family history of CRC or polyps and a gene mutation.

Genomic alterations in distal bile duct carcinoma by comparative genomic hybridization and karyotype analysis

We report genomic abnormalities identified in 14 human primary common bile duct carcinomas analyzed by cytogenetics or comparative genomic hybridization, or both. Combining the results of the two methods of analysis, 11 chromosomal arms were observed to be gained in whole or in part, and 9 chromosomal arms were lost in whole or in part in at least four tumors each. The most frequently lost chromosomal regions were, in decreasing order: 18q (eight tumors); 6q and 10p (seven tumors each); 8p, 12q, and 17p (six tumors each); and 7q, 12p, and 22q (four tumors each). The most frequently gained regions were 8q and 20q (six tumors each); 12p, 17q, and Xp (five tumors each); and 2q, 6p, 7p, 11q, 13q, and 19q (four tumors each). These results are similar to those we have previously reported in pancreatic cancer and suggest that carcinomas of the common bile duct and pancreas share a number of genetic changes.

Detection of microsatellite instability by fluorescence multiplex polymerase chain reaction

We have created a clinical molecular diagnostic assay to test for microsatellite instability (MSI) at multiple loci simultaneously in paraffin-embedded surgical pathology colon resection specimens. This fluorescent multiplex polymerase chain reaction (PCR) assay analyzes the five primary microsatellite loci recommended at the 1997 National Cancer Institute-sponsored conference on MSI for the identification of MSI or replication errors in colorectal cancer: Bat-25, Bat-26, D2S123, D5S346, and D17S250. Amplicon detection is accomplished by capillary electrophoresis using the ABI 310 Genetic Analyzer. Assay validation compared 18 specimens previously assessed by radioactive PCR and polyacrylamide gel electrophoresis detection to results generated by the reported assay. Germline and tumor DNA samples were amplified in separate multiplex PCR reactions, sized in separate capillary electrophoresis runs, and compared directly to identify novel length alleles in tumor tissue. A concordance of 100% between the two modalities was achieved. The multiplex assay routinely detected a subpopulation of 10% tumor alleles in the presence of 90% normal alleles. A novel statistical model was generated that corroborates the validity of using results generated by analysis of five independent microsatellites to achieve a single overall MSI diagnosis. The assay presented is superior to standard radioactive monoplex PCR, polyacrylamide gel electrophoretic analysis, primarily due to the multiplex PCR format.

Cytogenetics and cancer

Techniques based on fluorescence in situ hybridization (FISH) have bridged the gap between molecular genetics and conventional cytogenetics. Since its introduction in the late 1980s, advanced FISH-based methods have greatly enhanced the cytogenetic analysis of hematopoietic and solid tumors and are rapidly gaining ground in clinical cytogenetic diagnostics. As interest in FISH technologies has grown, it has inspired an era of new FISH-based technologies such as multiplex FISH, spectral karyotyping, and comparative genomic hybridization. In this review, the focus is on the impact of these technologies in the field of cancer genetics.

Breakpoints of the t(11;18)(q21;q21) in mucosa-associated lymphoid tissue (MALT) lymphoma lie within or near the previously undescribed gene MALT1 in chromosome 18

Lymphomas arising in mucosa-associated lymphoid tissue (MALT) are indolent B-cell tumors that have a predilection for epithelial sites and often develop in a setting of chronic inflammation or autoimmunity. As many as 50% of low-grade MALT lymphomas contain an (11;18)(q21; q21) chromosomal translocation. Using fluorescence in situ hybridization, we have analyzed the position of recombination within chromosome 18 DNA in three examples of MALT lymphoma bearing this translocation. In all three cases, the breakpoint maps to DNA in BAC b357H2, covering about 150 kb of sequence. A previously undescribed, ubiquitously expressed gene, which we refer to as MALT1, was identified within this sequence and was found to be broken in one case for which we have definitively located the position of recombination between chromosomes 18 and 11. The sequence of this gene indicates the presence of two immunoglobulin-like C2 domains and a region of partial homology to caspases, suggesting a possible role for MALT1 in the regulation of apoptosis.

Philadelphia chromosome-negative engraftment after autologous transplantation with granulocyte-macrophage colony-stimulating factor for chronic myeloid leukemia

Autologous bone marrow transplantation (BMT) has not been curative in chronic myeloid leukemia (CML), because of the inability to purge CML from the autograft and the absence of the allogeneic T cell-mediated antileukemic activity. However, recent advances demonstrate that normal progenitors can be selected from CML marrows by a variety of techniques, including isolation by their small size. Furthermore, we found that myeloid growth factors have a potent antileukemic effect against CML progenitors in vitro by inducing their terminal differentiation. Based on these data, we initiated a trial of autologous BMT in patients with high-risk CML. Autografts were processed in an attempt to enrich for normal progenitors, first by isolating small cells by counterflow centrifugal elutriation and then incubating them in granulocyte-macrophage colony-stimulating factor (GM-CSF) for 72 hours. After a conditioning regimen of busulfan and cyclophosphamide, all patients received GM-CSF daily for 2 months. The median age of the 13 patients in the trial was 45 years (range 17-56 years). The median duration of disease before BMT was 24 months (range 13-72 months). Eight patients were in chronic phase (CP), and five were in accelerated phase (AP). All patients failed to achieve a cytogenetic response to interferon-alpha and were 100% Philadelphia chromosome (Ph)+ before BMT. There were three transplant-related deaths, all AP patients. All of the remaining 10 patients engrafted with some degree of Ph- hematopoiesis; despite high-risk features, nine patients engrafted 100% Ph-. All patients relapsed cytogenetically at a median of 6 months (range 4-22 months). These results demonstrate that autologous BMT can consistently induce complete Ph- engraftment in CP patients. GM-CSF appears to produce a clinical antileukemic effect against CML after autologous BMT.

Consistency of isochromosome 7q and trisomy 8 in hepatosplenic gammadelta T-cell lymphoma: detection by fluorescence In situ hybridization of a splenic touch-preparation from a pediatric patient

Hepatosplenic gamma-delta (gammadelta) T-cell lymphoma is a rare but increasingly recognized lymphoid malignancy predominantly affecting young adult males. It is not well appreciated in the pediatric population. We report the third case of this aggressive lymphoma in a child as well as additional support for the consistency of the recently discovered cytogenetic abnormalities, isochromosome 7q and trisomy 8, which in this case were documented using fluorescence in situ hybridization (FISH) of a touch-preparation of the spleen.

Recurrent involvement of 2p23 in inflammatory myofibroblastic tumors

Inflammatory myofibroblastic tumor (IMT) is a relatively rare soft tissue tumor. The reactive versus neoplastic pathogenesis of this tumor is unresolved. We found clonal chromosome aberrations involving 2p23 upon metaphase analysis of two IMTs. Fluorescence in situ hybridization with a probe flanking the ALK gene at 2p23 demonstrated rearrangement of the probe in both of these cases and in a third case, and immunohistochemistry revealed ALK expression in all three cases. 2p22-24 involvement has been reported previously in four additional cases of IMT. We suggest that chromosomal rearrangements involving 2p23 near or within ALK are recurrent alterations in IMT and that ALK may have a novel role outside its previously recognized realm of lymphoid neoplasms.

A human-murine chimera model for in utero human hematopoietic stem cell transplantation

To date, 16 in utero hematopoietic stem cell (HSC) transplants for diseases other than immunodeficiency disorders have been reported. No therapeutic level of engraftment was detected in 15 of these transplants. To overcome engraftment failure, we transplanted a very large number (5 billion paternal CD34+ cells/kg) of HSCs to a fetus with leukodystrophy during the first trimester of gestation. As reported previously, the fetus died in utero 7 weeks after the procedure and the cause of death appeared to be overwhelming donor engraftment. In the present investigation, we developed a human-murine chimera model to test for the optimal donor cell dose for human in utero transplantation. We found a strong correlation between the level of donor engraftment in three human fetuses transplanted for leukodystrophy during the first trimester of gestation and the results of parallel xenotransplants of the same human donor cells using the NOD/SCID mouse model. This small animal model appears to predict both extremes of hyperengraftment (seen in the first human fetus transplanted) and engraftment failure (seen in the second and third human fetuses transplanted in utero). These and future correlated clinical and laboratory assay results may be useful for the development of in utero transplants for a variety of congenital disorders.

Genetic analysis of ovarian germ cell tumors by comparative genomic hybridization

Ovarian germ cell tumors (OGCTs) show a heterogeneity that is not seen in their testicular counterparts and include benign mature cystic teratomas, intermediate immature teratomas, malignant germ cell tumors [GCTs (dysgerminomas, endodermal sinus tumors, and mixed GCTs)], and GCTs arising in dysgenetic gonads of 46,XY individuals. Comparative genomic hybridization was used to analyze 27 OGCTs for regions of relative gain or loss. The analysis of 21 malignant OGCTs (12 dysgerminomas, 6 endodermal sinus tumors, and 3 mixed GCTs) demonstrated genetic alterations similar to those reported in adult testicular GCTs. The most common regions gained include chromosomes 12p (16 of 21 tumors), 21 (10 of 21 tumors), 8 (8 of 21 tumors), and 1q (6 of 21 tumors). The most common region lost was chromosome 13. Regions of high-level gain were identified at 12p11-12 and 4q11. The profile of gains and losses was similar in the different histological subtypes within this category. One tumor presented in a 46,XY patient; this tumor was diploid and showed a gain of 12p. Immature teratomas (six cases) showed only one case with an abnormality, which was a gain of chromosome 14. We conclude that malignant OGCTs are genetically similar to those found in the adult testis; however, immature teratomas show no consistent gains or losses and are therefore different from those presenting in the adult testis. A review of the literature suggests that genetic abnormalities in this group may herald a worse prognosis. Lastly, OGCTs in dysgenetic gonads arise in a diploid rather than a tetraploid cell line, yet they also show a gain of 12p.

E1A transformed normal human prostate epithelial cells contain a 16q deletion

The difficulty of maintaining long-term prostate cell cultures has hindered the development of essential models for understanding prostate cancer. We report here the establishment of two 12S E1A transformed non-tumorigenic prostate epithelial cell strains, and their characterization. The two clonal cell strains, TP2 and TP4, proliferated for approximately 40 passages before senescence. Both exhibited a strong dependence on exogenous peptide growth factors and an immunophenotype characteristic of their prostate epithelial origin. Cytogenetic analysis revealed a consistent deletion on the q arm of chromosome 16 in TP2 with an otherwise normal karyotype. Band-specific microdissection generated region-specific probes from 16q23, which when used in fluorescence in situ hybridization (FISH) revealed that the region was deleted in 83% of metaphases analyzed. By cytogenetic analysis and FISH, the q arm of 16 was found deleted from the genome of TP4 in 60% of cells analyzed. Lost sequences on 16q-16q23 in particular--in prostate cancer have been observed by a variety of methods. Localization of common region of deletion has been determined from these studies to be distal to 16q23. Our findings suggest that 16q23 may be of major importance in the development of prostate cancer, and may harbor tumor suppressor elements.

Pancreatic adenocarcinomas with DNA replication errors (RER+) are associated with wild-type K-ras and characteristic histopathology. Poor differentiation, a syncytial growth pattern, and pushing borders suggest RER+

The clinical and pathological features of carcinomas of the pancreas with DNA replication errors (RER+) have not been characterized. Eighty-two xenografted carcinomas of the pancreas were screened for DNA replication errors using polymerase chain reaction amplification of microsatellite markers. Cases with microsatellite instability in at least two markers of a minimum of five tested were considered RER+. RER status was correlated with histological appearance, karyotype of the carcinomas when available, K-ras mutational status, and patient outcome. Three (3.7%) of the eighty-two carcinomas were RER+. In contrast to typical gland-forming adenocarcinomas of the pancreas, all three RER+ carcinomas were poorly differentiated and had expanding borders and a prominent syncytial growth pattern. Neither a Crohn's-like lymphoid infiltrate nor extracellular mucin production were prominent. Ductal adenocarcinomas of the pancreas typically contain a mutant K-ras gene, yet all three RER+ carcinomas had wild-type K-ras. One of the three RER+ carcinomas was karyotyped and showed a near diploid pattern. All three of the RER+ tumors were removed via Whipple resection. One of the three patients is free of disease 16 months after pancreaticoduodenectomy, one is alive and free of tumor at 52 months but developed two colon carcinomas during this period, and the third died of pancreatic cancer at 4 months. None of the three patients had a family history of colorectal carcinoma. A review of the K-ras wild-type carcinomas in a previously characterized series of pancreatic carcinomas with known K-ras mutational status identified two additional cancers with poor differentiation, a syncytial growth pattern, and pushing borders. Both of the cancers were diploid and both patients were longterm survivors (over 5 years). The inclusion of such patients in previous prognostic studies of pancreas cancer may explain the failure of histological grade to be a predictor of prognosis. These data suggest that DNA replication errors occur in a small percentage of resected carcinomas of the pancreas and that wild-type K-ras gene status and a medullary phenotype characterized by poor differentiation, and expanding pattern of invasion, and syncytial growth should suggest the possibility of DNA replication errors in carcinomas of the pancreas.

Development and characterization of a cytokine-secreting pancreatic adenocarcinoma vaccine from primary tumors for use in clinical trials

Preclinical studies with murine tumor models have demonstrated that tumor cell vaccines engineered to secrete certain cytokines in a paracrine fashion elicit systemic immune responses capable of eliminating small amounts of established tumor. In particular, tumors that express the cytokine GM-CSF produce potent systemic antitumor immune responses against poorly immunogenic murine tumors. These results have encouraged the development of paracrine-cytokine secreting tumor vaccines for gene therapy of human cancer. GM-CSF recruits professional antigen-presenting cells, which in turn activate effector T cells. These findings suggest that allogeneic as well as autologous tumor cells can be used as the tumor source for developing cancer vaccines. A major obstacle to creating genetically modified human allogeneic tumor vaccines is the absence of stable cell lines required for efficient gene transfer, because most human tumors isolated from primary surgical specimens fail to proliferate in long-term culture. We have developed a method for the routine generation of in vitro cell lines from primary tumors of the pancreas. This method overcomes the common problem of stromal and fibroblast overgrowth that can inhibit the in vitro expansion of many histologic types of tumors. In addition, we have analyzed 12 of these cell lines for cytokeritin and mutated K-ras expression to demonstrate that they derive from the original epithelial tumor tissue. The lines can be genetically modified to stably express the cytokine GM-CSF. These methods should be helpful to investigators attempting to establish cell lines from other histologic tumor types for the development of allogeneic genetically modified tumor vaccines.

Glucose metabolism and insulin receptor binding and mRNA levels in tissues of Dahl hypertensive rats

Increased insulinemic response to an oral glucose load has been demonstrated in Dahl salt-sensitive hypertensive rats. To determine whether this abnormality is mediated at the level of the insulin receptor, we compared insulin receptor binding and mRNA levels in tissues of Dahl salt-sensitive rats (DS) and in their normotensive controls, Dahl salt-resistant rats (DR). To evaluate possible influences of dietary sodium intake, rats were fed either low (0.07% NaCl) or high salt (7.5% NaCl) chow until the DS became hypertensive, and then were killed by decapitation. Fasting plasma glucose and plasma insulin levels did not differ between DR and DS rats and were not affected by salt intake. In response to an oral glucose load, plasma glucose had a similar increase in DR and DS rats, but the increase in plasma insulin was significantly greater in DS rats. Scatchard analysis of binding was obtained from in situ autoradiographic studies performed in frozen skeletal muscle and kidney sections, and insulin receptor mRNA levels were measured by slot-blot hybridization. Number and affinity of insulin receptors were comparable in skeletal muscle and kidney of DR and DS rats and, in both groups, binding parameters were not affected by dietary sodium chloride. Hepatic and renal insulin receptor mRNA levels were also comparable in DR and DS rats fed either low or high salt chow. Thus, increased plasma insulin response to oral glucose load is associated with normal insulin receptor binding and gene expression in peripheral tissues in rats with Dahl hypertension. A postreceptor defect is likely responsible for the decreased sensitivity to insulin in this model of genetic hypertension.

Blastic natural killer cell leukemia/lymphoma: a clinicopathologic study

The classification of natural killer (NK)-cell and NK-like T-cell malignancies has undergone significant evolution in recent years. Although examples of NK-cell tumors resembling acute leukemia have been described anecdotally as blastic, blastoid, or monomorphic NK-cell leukemia/lymphoma (NKL/L), the clinical and pathologic features of these tumors have not been systematically defined. We report four patients with blastic NKL/L and describe the clinical, pathologic, and immunophenotypic findings in these cases. All patients were elderly (58-82 years) and presented with cutaneous plaques. Two patients also had adenopathy, and three patients had marrow involvement at presentation. Biopsy of cutaneous lesions showed atypical superficial and deep dermal lymphoid infiltrates. Involved lymph nodes were architecturally effaced by an interfollicular infiltrate with blastic cytologic features. In Wright-Giemsa-stained blood or marrow smears, tumor cells had finely distributed nuclear chromatin, many with nucleoli, and variable amounts of cytoplasm. In contrast to many NK and NK-like T-cell disorders, azurophilic cytoplasmic granules were absent or inconspicuous. The tumor cells were immunophenotypically distinctive. They expressed intermediate density CD45, as is characteristic of blasts; in addition, the cells were positive for HLA-DR, CD2, CD4, and the NK-associated antigen CD56. Surface CD3, cytoplasmic CD3, and CD5 were negative in all cases tested, whereas CD7 was expressed in two cases. In formalin-fixed tissue, tumor cells marked with antibodies to CD43, but not with other T- or B-lineage-related antibodies. All three cases studied for Epstein-Barr viral RNA by in situ hybridization were negative. Although treatments varied, all three patients with clinical follow-up died within months of the diagnosis. The clinical course in two patients culminated in an overtly leukemic phase. These findings suggest that blastic NKL/L represents a distinct clinicopathologic entity, characterized by cutaneous, nodal, and marrow involvement by blastic cells with immunophenotypic characteristics of true NK cells. The disease afflicts elderly patients, pursues an aggressive course, and may culminate in overt leukemia.

Effects of angiotensin II on insulin receptor binding and mRNA levels in normal and diabetic rats

Both the density and level of mRNA encoding insulin receptors in the kidney are inversely related to the dietary sodium content, suggesting a feedback mechanism that limits the insulin-induced sodium retention when extracellular fluid volume is expanded. Because angiotensin II affects tissue sensitivity to insulin in humans, we investigated whether angiotensin II affects insulin receptor binding and mRNA levels in the kidney, liver, and renal arteries of normal rats and rats with streptozotocin-induced diabetes mellitus. Non-diabetic and diabetic rats were infused for 7 days with either vehicle or angiotensin II at a rate of 200 ng. kg-1. min-1. In a separate experiment, normal rats were treated with an angiotensin converting enzyme inhibitor (captopril, 100 mg/dl in the drinking water) or vehicle for 7 days. Regional analysis of insulin receptor binding in the kidney and renal arteries was performed by an in situ technique using computerized microdensitometry and emulsion autoradiography. Insulin receptor mRNA levels were determined in renal and hepatic tissue by Northern blot hybridization and normalized with 28S rRNA. No differences in blood pressure were observed among diabetic and non-diabetic rats infused with either vehicle or angiotensin II, whereas captopril-treated rats had significantly lower blood pressure levels than their respective controls. Angiotensin II significantly decreased plasma renin concentration in both non-diabetic and diabetic rats. Insulin receptor number was significantly greater in the renal cortex of diabetic rats than in non-diabetics, whereas no significant differences were found in the outer medulla, inner medulla, or renal arteries. Angiotensin II infusion did not affect either the number or affinity of insulin receptors in any of the renal regions studied. Insulin receptor mRNA levels were significantly greater in the kidney and liver of diabetic rats than in non-diabetics and were not affected by angiotensin II infusion. Similar to angiotensin II infusion, captopril treatment did not affect either renal insulin receptor binding or mRNA levels. Thus, diabetic rats have increased insulin receptor binding and mRNA levels in comparison to non-diabetic rats. Angiotensin II infusion and captopril treatment do not affect insulin receptor binding and mRNA levels in the kidney, arguing against a role for this peptide in the modulation of renal sensitivity to insulin.

JAK3: expression and mapping to chromosome 19p12-13.1

We cloned JAK3, the most recently described member of the JAK family of intracellular tyrosine kinases, from normal human CD34+ RNA. JAK3 is involved in the signal transduction pathways of the IL-2, IL-4, IL7, IL-9, and IL-15 receptors by association with their common gamma-chain (gamma[c]). JAK3 is critical to lymphoid development, as recently established by the linking of mutations in JAK3 to a subgroup of patients with SCID and the generation of JAK3-null mice with severe disruptions in normal lymphocytic development. However, JAK3 expression is not restricted to the lymphocytic compartment of bone marrow but is found in a wide range of tissues of both hematopoietic and non-hematopoietic origin. Northern blot analysis indicates that JAK3 is also expressed in adult placenta, lung, liver, kidney, pancreas, spleen, thymus, ovary, and small intestine. RNAse protection assays and RT-PCR indicate that JAK3 is expressed in a variety of leukemic-derived hematopoietic cell lines with myeloid and/or lymphoid phenotypes. In normal human bone marrow, JAK3 is expressed in the CD34+/lineage- fraction, which is highly enriched in hematopoietic stem/progenitor cells. In addition, we found a splice variant of JAK3 which is formed by the splicing of JAK3 with exon II of the leydig insulin-like (LEY I-L) hormone. RT-PCR and RNAse protection assay analyses indicate that this variant (termed I-JAK3) is normally expressed in almost all hematopoietic and non-hematopoietic tissues shown to express JAK3. Using fluorescence in situ hybridization we have localized JAK3 to 19p12-13.1, the same region of chromosome 19 to which the LEY I-L hormone maps (19p12-13.2).

Chromosomal localization and partial genomic structure of the human peroxisome proliferator activated receptor-gamma (hPPAR gamma) gene

We determined the chromosomal localization and partial genomic structure of the coding region of the human PPAR gamma gene (hPPAR gamma), a nuclear receptor important for adipocyte differentiation and function. Sequence analysis and long PCR of human genomic DNA with primers that span putative introns revealed that intron positions and sizes of hPPAR gamma are similar to those previously determined for the mouse PPAR gamma gene[13]. Fluorescent in situ hybridization localized hPPAR gamma to chromosome 3, band 3p25. Radiation hybrid mapping with two independent primer pairs was consistent with hPPAR gamma being within 1.5 Mb of marker D3S1263 on 3p25-p24.2. These sequences of the intron/exon junctions of the 6 coding exons shared by hPPAR gamma 1 and hPPAR gamma 2 will facilitate screening for possible mutations. Furthermore, D3S1263 is a suitable polymorphic marker for linkage analysis to evaluate PPAR gamma's potential contribution to genetic susceptibility to obesity, lipoatrophy, insulin resistance, and diabetes.

The renin-angiotensin system and compensatory renal hypertrophy in the rat

Angiotensin II (Ang II) may act as an angiogenic and growth promoting factor in different tissues. To assess the role of Ang II in compensatory renal growth following unilateral nephrectomy (UNX), we measured renin, angiotensinogen, and Ang II type 1 (AT1) receptor mRNA levels, as well as Ang II receptor density, in two groups of Sprague-Dawley rats 7 days after either sham operation or UNX. Half of each group received either no treatment or an angiotensin-converting enzyme inhibitor (100 mg/dL captopril in the drinking water, initiated at the time of the intervention). Following UNX, the ratio of kidney weight to body weight (KW/BW) in untreated animals was greater than in rats undergoing sham UNX (0.46 +/- 0.01 v 0.37 +/- 0.01%, P < .01). Neither renal renin, nor renal or hepatic angiotensinogen mRNA levels, determined by slot blot hybridization, changed significantly after UNX. Ang II receptor density in glomeruli, determined using an 125I-Sar1-Ile8 Ang II in situ receptor binding assay on frozen kidney sections, did not change significantly after UNX, nor did renal AT1 receptor mRNA. In captopril-treated rats, KW/BW was greater in UNX than in sham operated rats (0.44 +/- 0.01 v 0.37 +/- 0.01%, P < .01), similar to results in untreated animals. Renal and hepatic angiotensinogen mRNA levels were not affected by captopril treatment and did not change further in response to UNX. Captopril treatment increased renin mRNA in both sham operated and UNX rats as compared with untreated controls, but had no significant effect on Ang II receptor density and AT1 receptor mRNA; and no change was observed in either variable as a consequence of UNX. Thus, compensatory renal hypertrophy following UNX occurred in the absence of measurable changes in components of the renin-angiotensin system, and despite functionally significant inhibition of this system by captopril. These data do not support a critical role for Ang II in compensatory renal hypertrophy.

The structural basis of molecular genetic deletions. An integration of classical cytogenetic and molecular analyses in pancreatic adenocarcinoma

Molecular genetic alterations are known to be important in human carcinoma, but the structural basis of these changes is largely unknown. To examine the basis of these changes, we compared the karyotypic chromosomal abnormalities of primary pancreatic adenocarcinomas with the molecular changes identified in these same cancers. In 14 cancers with abnormal karyotypes, 65% (123 of 188) of the chromosomal arms with molecular loss of heterozygosity (LOH) were associated with karyotypic structural anomalies. Karyotypic changes accounting for these molecular allelic losses included 83 chromosome losses, 18 partial deletions, nine isochromosomes, eight additions, and five translocations. Eight bomozygous deletions were also identified by molecular analyses. Of the three homozygous deletions identified at 9p21, the only karyotypic change was a single case in which one entire copy of chromosome 9 was deleted. Of the four homozygous deletions identified at 18q21.1, one showed a loss of both copies of chromosome 18, two showed a loss of one copy of chromosome 18, and the fourth had two structurally normal copies of chromosome 18. One homozygous deletion was identified at 13q12.3, and the karyotype revealed the loss of one entire copy of chromosome 13. The second copy of chromosome 13 in this carcinoma was structurally normal. These results indicate that chromosomal structural anomalies can account for two-thirds of the LOH in pancreatic adenocarcinomas and that most homozygous deletions are likely to be interstitial chromosomal deletions that are below the detection limit of conventional karyotypic analyses. Some of the molecular deletions detected as LOH on chromosomes with karyotypically normal structure can be explained by chromosomal loss with reduplication of the remaining chromosome.

Engraftment following in utero bone marrow transplantation for globoid cell leukodystrophy

To date, in utero bone marrow transplantation (BMT) has had limited success, largely because of poor donor engraftment. The poor engraftment is probably the result of performing the procedure late in gestation after significant fetal immunocompetence has developed and/or transplanting insufficient numbers of donor hematopoietic stem cells for competing successfully with ongoing fetal hematopoiesis. To overcome these problems, we performed in utero BMT on a fetus with globoid cell leukodystrophy during the first trimester of gestation using selected paternal bone marrow stem (CD34+) cells. CD34 selection allowed a substantially greater number of stem cells to be transplanted. Although the fetus died 7 weeks after the procedure (during the 20th week of gestation), full donor engraftment was established. Moreover, the cause of death appeared to be overwhelming donor engraftment and leukostasis with paternal myeloid cells infiltrating most tissues. The ability of in utero BMT to produce this degree of engraftment provides great promise for the use of this approach in the treatment of a variety of inherited disorders that can be diagnosed prenatally.

Renal antioxidant enzyme mRNA levels are increased in rats with experimental diabetes mellitus

Exposure to high glucose concentrations increases the mRNA levels of oxygen radical scavenging enzymes in cultured endothelial cells, suggesting a compensatory response to increased free radical production. To test the hypothesis that this response also occurs in vivo, Cu.Zn-superoxide dismutase (Cu.Zn-SOD) and catalase mRNA levels, were measured in the kidneys of Sprague-Dawley rats 17 days after intravenous injection of streptozotocin (60 mg/kg body weight) and compared with those of control rats. Diabetic rats were either left untreated or given differing insulin regimens (2. 3-8, 6-10 IU/day) in two different experiments that were designed to achieve varying degrees of metabolic control. Cu,Zn-SOD and catalase mRNA levels were measured by Northern blot hybridization and standardized by 28S ribosomal RNA determination. Renal Cu,Zn-SOD and catalase mRNA levels were significantly greater in untreated diabetic and in low-dose (2 IU/day) insulin-treated rats than in controls. Treatment with a moderate dose (3-8 IU/day) of insulin normalized catalase but not Cu,Zn-SOD mRNA levels. The highest insulin regimen (6-10 IU/day), in addition to achieving complete metabolic control as evidenced by normal growth and plasma glucose levels, normalized both catalase and Cu,Zn-SOD mRNA levels. Thus, in rats with streptozotocin-induced diabetes Cu,Zn-SOD and catalase renal mRNA levels are greater than in normal rats. This difference is prevented by sufficient insulin dosage to normalize plasma glucose and might be due to an increased production of free radicals.

Ontogenic expression of renal and hepatic angiotensin II receptor genes in the rat

In addition to its well-characterized renal hemodynamic effects, angiotensin II (Ang II) promotes growth of cultured glomerular and tubular cells, suggesting a possible role in renal development. To better define potential developmental effects of Ang II, we examined the expression of Ang II receptors in embryonic (E19) and postnatal (1, 2, 3, 10 days, 6 weeks, 3 and 9 months) rat kidneys, using in situ autoradiography and the nonpeptide antagonists losartan and PD-123177 to identify receptor subtypes. At E19, 125I-[Sar1, Ile8]Ang II binding was equally reduced by losartan and PD-123177, indicating the presence of both AT1 and AT2 receptors. A progressive increase in Ang II receptor density occurred after birth, reaching a plateau at day 10. At that time, the AT1 subtype predominated and was virtually the sole subtype present thereafter. Ang II receptor density and AT1 mRNA levels decreased in aging rats. Total AT1 receptor mRNA levels in both kidney and liver were determined by Northern hybridization analysis using a radiolabeled AT1 anti-sense cRNA probe. In both tissues, AT1 mRNA levels increased rapidly following birth, reached a maximum on day 10 and decreased thereafter. To further characterize the ontogenic effects on AT1 gene expression, renal AT1A and AT1B receptor mRNA isoforms were determined by reverse transcription and the polymerase chain reaction. No significant differences were observed during maturation between the relative levels of AT1A and AT1B mRNAs, with the AT1A isoform accounting for approximately 78% at any time point. Thus, renal AT1 receptor density increases rapidly after birth, in association with an increase in both AT1A and AT1B receptor gene expression. As the predominant receptor isoform in the adult kidney, the AT1A receptor may account for the majority of the effects of Ang II on glomerular and tubular function.