Visualization of fine-scale genomic structure by oligonucleotide-based high-resolution FISH

The discovery of complex structural variations that exist within individual genomes has prompted a need to visualize chromosomes at a higher resolution than previously possible. To address this concern, we established a robust, high-resolution fluorescence in situ hybridization (FISH) method that utilizes probes derived from high complexity libraries of long oligonucleotides (>150 mers) synthesized in massively parallel reactions. In silico selected oligonucleotides, targeted to only the most informative elements in 18 genomic regions of interest, eliminated the need for suppressive hybridization reagents. Because of the inherent flexibility in our probe design methods, we readily visualized regions as small as 6.7 kb with high specificity on human metaphase chromosomes, resulting in an overall success rate of 94%. Two-color FISH over a 479-kb duplication, initially reported as being identical in 2 individuals, revealed distinct 2-color patterns representing direct and inverted duplicons, demonstrating that visualization by high-resolution FISH provides further insight in the fine-scale complexity of genomic structures. The ability to design FISH probes for any sequenced genome along with the ease, reproducibility, and high level of accuracy of this technique suggests that it will be powerful for routine analysis of previously difficult genomic regions and structures.

Benign copy number changes in clinical cytogenetic diagnostics by array CGH

A database of apparently benign copy number variants (bCNVs) detected by a Spectral Genomics Inc./PerkinElmer BAC array platform has been maintained through the University of Utah Comparative Genomic Hybridization laboratory since 2005. The target population for this database represents 1,275 patients with abnormal phenotypes, primarily children referred for developmental delay and mental retardation. These bCNVs are independent of any identified copy number abnormality detected. The most common 35 bCNVs observed and their frequencies are reported here, and a subset of ten of the patients studied was evaluated on a new oligonucleotide CNV array set designed by Agilent Technologies. There was a 76% concordance of calls for these 35 bCNVs detected by both array platforms in the same patients. The higher resolution of the Agilent oligonucleotide array compared to the BAC array allowed determination of the precise breakpoints of the observed CNVs, in addition to documentation of additional CNVs of smaller sizes. As expected, observed CNVs and their frequencies were generally consistent with those of other previously published and available databases, including the Database of Genomic Variants (http://projects.tcag.ca/variation/). The availability of these data should assist other clinical laboratories in the evaluation of CNVs of unknown clinical significance.

Triple negative status as a risk factor for the development of brain metastases in African American breast cancer patients

Abstract #2093

Background: Previous studies have described triple negative (TN) breast cancer (ER/PR/ HER2/neu negative) as an aggressive and poor prognostic phenotype with higher relapse rate (RR), distant RR, and shorter survival. The incidence of TN breast cancer has reportedly been higher (30-35%) in African American (AA) women compared to the general population (15%) but the clinical outcomes of TN patients (pts) who develop brain metastases compared to the non-triple negative (NTN) group has not been well described.
 Methods: We retrospectively reviewed tumor registry data from a large academic medical center serving an inner city population. A total of 282 AA women with invasive breast cancer were identified from 1994-2006 and 248 were determined to be in stages I-III. Characteristics evaluated include age, TNM stage at diagnosis, ER, PR, Her2/neu status, and grade. The RR, distant RR, rate of brain metastases, time from diagnosis to brain metastases, and overall survival were determined.
 Results: The incidence of TN disease in AA women was 30% (82/282). Median age (57 yrs) was similar in both TN and NTN groups. With a median follow-up of 5.5 years, the RR (30% vs. 14%; p=0.02) and distant RR (22% vs. 10%; p=0.02) were higher for the TN vs. NTN group. Six of 72 (9%) TN pts developed brain metastases compare to 6/178 (3%) in NTN group. There was a shorter time to development of brain metastases (1.7 vs. 6.1; p=0.01) and a lower survival time after brain metastases (0.6 yrs vs. 1.6 yrs) in the TN vs. NTN group.
 
 Conclusion: This study represents one of the largest reported series of AA women with breast cancer. TN pts are at higher risk of developing brain metastases. Not only the time to develop brain metastases was shorter but overall survival after development of brain metastases remained poor in TN group compared to NTN group. TN status should be considered as an independent risk factor for the development of brain metastases.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2093.

Construction of a counterselection-based in-frame deletion system for genetic studies of Streptococcus mutans

Genetic studies of Streptococcus mutans have benefited greatly from the numerous techniques that have been successfully adapted for use in this organism. One notable exception is the lack of a negative selection system that can be employed for the easy isolation of markerless in-frame deletions. In this study, we report the development of a galK/galactose-based negative selection system in S. mutans for this purpose. This system consists of a recipient strain (IFD140) that contains a deletion in the galKTE operon and a suicide vector (pIFD-Sm) that carries the S. mutans galK open reading frame fused to the constitutive lactate dehydrogenase (ldh) promoter. Using this system we created a markerless in-frame deletion in the beta-galactosidase (lacG) gene within the S. mutans lactose operon. After vector integration, plasmid excision after counterselection appeared to have occurred in 100% of the galactose-resistant colonies and resulted in in-frame deletions in 50% of the screened isolates. Based on the ratio of galactose-resistant cells to total cells, we determined that plasmid excision occurred at a frequency of approximately 1/3000 cells. Furthermore, the simplicity of this system should make it adaptable for use in numerous other gram-positive and gram-negative organisms.

Clonal T-Large Granular Lymphocyte Proliferation in Solid Organ Transplant Recipients

Large granular lymphocytic (LGL) leukemia is a rare disorder, usually caused by clonal proliferation of CD3+ CD57+ T-LGL cells. T-cell clonality is confirmed by rearrangements of the T-cell receptor (TCR) gene. Characteristic features of T-LGL leukemia include neutropenia, anemia, and constitutional symptoms such as fatigue. Many solid organ transplant recipients experience similar symptoms and have neutropenia and anemia often attributed to immunosuppressive therapy. The purpose of this study was to determine the prevalence of T-LGL proliferation in solid organ transplant recipients and demonstrate its association with leukopenia and anemia. Twenty-three cardiac and renal transplant patients were evaluated by peripheral smear examination, flow cytometry, and TCR gene rearrangement study by polymerase chain reaction. Ten of 14 (71%) cardiac transplant patients and 4 of 9 (44%) renal transplant patients, without evidence of either allograft rejection or a viral syndrome, were found to have clonal expansion of T-LGL cells. Constitutional symptoms were present in 30% of these patients. Anemia of <10 g/dL was seen in 75% of renal transplant and 10% of cardiac transplant patients. None of these patients had significant neutropenia defined as absolute neutrophil count of 1500 mu/L. Most of the patients did not require any specific therapeutic intervention. Although TCR gene rearrangement is considered a hallmark of T-LGL leukemia, we believe that this monoclonality is not a true form of posttransplant lymphoproliferative disorder. Constant antigenic stimulus from the allograft may be the underlying etiology of clonal expansion and may contribute to cytopenias and fatigue seen in transplant patients.

Severe periodontitis in a 5-year-old girl with hyperimmunoglobulin E syndrome

The hyperimmunoglobulin E syndrome (HIES) is a multisystem disorder that affects the: (1) dentition; (2) skeleton; (3) connective tissues; and (4) immune system. Little is known about periodontal manifestations of the syndrome. The purpose of this report was to describe a 5-year-old girl with suspected autosomal-recessive HIES syndrome who revealed profusely bleeding and painful gingiva and generalized aggressive periodontitis. A polymerase chain reaction (PCR)-based microbiological examination detected Porphyromonas gingivalis, Tannerella forsythia, Prevotella nigrescens, Treponema denticola, Eikenella corrodens, and Campylobacter rectus in the deep periodontitis lesions. The extraction of all deciduous teeth due to a poor prognosis and risk of systemic infection led to resolution of the oral inflammation. Long-term follow-up is required to determine the periodontal prognosis of the erupting permanent teeth.

Low incidence of HPV DNA in sera of pretreatment cervical cancer patients

OBJECTIVE

The aim of this study was to investigate the feasibility of using DNA in the circulation as a diagnostic tool for cervical cancer.

METHODS

We used PCR followed by Southern hybridization to detect human papillomavirus (HPV) DNA in serum samples taken from patients of cervical cancer before treatment.

RESULTS

A total of 60 samples were analyzed. In a set of 40 samples, without knowledge of the HPV DNA status in the corresponding cervical carcinomas, we could detect 8 (20%) positive samples, of which 7 (17.5%) were HPV 16 and 1 (2.5%) was HPV 18. In another set of 20 samples, known to be HPV 16 infected in the corresponding cervical carcinomas, we detected only 4 (20%) HPV-16-positive samples. The occurrence of HPV DNA in sera of cervical cancer patients seems sporadic.

CONCLUSION

The low incidence indicates that serum HPV DNA has limited application in the diagnosis of cervical cancer.

The binding of a glycoprotein 120 V3 loop peptide to HIV-1 neutralizing antibodies. Structural implications

The structural and antigenic properties of a peptide ("CRK") derived from the V3 loop of HIV-1 gp120 protein were studied using NMR and SPR techniques. The sequence of CRK corresponds to the central portion of the V3 loop containing the highly conserved "GPGR" residue sequence. Although the biological significance of this conserved sequence is unknown, the adoption of conserved secondary structure (type II beta-turn) in this region has been proposed. The tendency of CRK (while free or conjugated to protein), to adopt such structure and the influence of such structure upon CRK antigenicity were investigated by NMR and SPR, respectively. Regardless of conjugation, CRK is conformationally averaged in solution but a weak tendency of the CRK "GPGR" residues to adopt a beta-turn conformation was observed after conjugation. The influence of GPGR structure upon CRK antigenicity was investigated by measuring the affinities of two cognate antibodies: "5023A" and "5025A," for CRK, protein-conjugated CRK and gp120 protein. Each antibody bound to all the antigens with nearly the same affinity. From these data, it appears that: (a) antibody binding most likely involves an induced fit of the peptide and (b) the gp120 V3 loop is probably conformationally heterogeneous. Since 5023A and 5025A are HIV-1 neutralizing antibodies, neutralization in these cases appears to be independent of adopted GPGR beta-turn structure.

A distinctive composite lymphoma consisting of clonally related mantle cell lymphoma and follicle center cell lymphoma

Although follicle center cell lymphoma and mantle cell lymphoma are both B cell non-Hodgkin's lymphomas (NHL), they are regarded as separate entities with distinct clinical, morphological, immunophenotypic and molecular characteristics. To our knowledge, the coexistence of these 2 lymphomas in the same patient has never been reported. We describe a 70-year-old woman with a long-standing history of follicle center cell lymphoma, cytological grade I, who subsequently developed a composite lymphoma consisting of well-demarcated foci of persistent follicle center cell lymphoma surrounded by mantle cell lymphoma. This morphological interpretation was supported by the presence of both bcl-1 and bcl-2 gene rearrangements, which are molecular genetic hallmarks of mantle cell lymphoma and follicle center cell lymphoma, respectively. Polymerase chain reaction (PCR) analysis for rearranged immunoglobulin heavy chain (IgH) genes showed a dominant band identical in size in microdissected tumor cells of the follicle center cell and mantle cell lymphomas. Cloning and sequence analysis of the PCR products revealed a common clone-specific IgH gene rearrangement in these 2 lymphomas. These findings suggest that this composite lymphoma represents the unusual evolution of a malignant B-cell clone that resulted in the development of 2 morphologically distinct but clonally related B-cell NHLs. These findings also show the importance of integrating morphological, immunophenotypic, and molecular data to enhance our understanding of the complex pathogenic interrelationships in lymphomagenesis.

Biopsy diagnosis of colitis: possibilities and pitfalls

The histopathologic diagnosis of inflammation is common in colorectal biopsies but is of limited value, if not further specified. We reviewed 280 endoscopic colorectal biopsy specimens for nonneoplastic disease from 100 consecutive patients in order to assess (a) the frequency of inflammation in excess of the physiologic infiltrate, (b) the frequency with which the cause of the inflammation could be specified, and (c) the interobserver variability in diagnosing inflammation. Based on the reviewers' impression, each case was classified into one of three categories: (I) normal or nonspecific change, (II) nonspecific inflammation, and (III) inflammation suggestive or diagnostic of specific cause. Inflammation was diagnosed in 68% of cases. The majority of these cases (75%) showed features typically associated with specific types of colitis, including Crohn's disease (n = 16), ulcerative colitis (n = 13), inflammatory bowel disease not otherwise specified (n = 5), infectious colitis (n = 6), ischemic colitis (n = 4), solitary rectal ulcer syndrome (n = 3), radiation colitis (n = 2), and lymphocytic colitis (n = 2). Interobserver variability was greatest in biopsy specimens interpreted by the reviewers as normal or showing nonspecific changes, most of which had been diagnosed as mild inflammation by the original pathologists. Etiologic classification of colitis was lacking in 59% of the cases interpreted by the reviewers as suggestive or diagnostic of a specific cause. We conclude that (a) the majority of colorectal biopsy specimens from patients with nonneoplastic disease in this series show inflammation, (b) the majority of such cases allow a specific cause of colitis to be suggested or firmly diagnosed, and (c) pathologists tend to overdiagnose the physiologic inflammatory infiltrate as evidence of colitis and underdiagnose specific etiologic types of colitis.

Additional mimics of mucinous mammary carcinoma: fibroepithelial lesions

To determine the origin and nature of mucinlike material in fine-needle aspiration (FNA) smears of the breast in noncancerous breast lesions, we studied breast FNA smears from four patients. All smears contained epithelial cells floating in a mucinlike background, which raised suspicion for mucinous (colloid) carcinoma. Mucicarmine stain was performed on one smear from each case. Subsequent tissue biopsy specimens were studied using mucicarmine, periodic acid-Schiff with and without diastase, and alcian blue stains at pH 2.7 and 0.9 on selected tissue sections. Correlation of the cytologic and histologic findings of each lesion was performed. The mucinlike background in all four FNA smears stained strongly with mucicarmine. Corresponding biopsy specimens revealed pseudoangiomatous hyperplasia in the first case, fibroadenoma and atypical ductal hyperplasia in the second, benign phyllodes tumor in the third, and fibroadenoma in the fourth. Each lesion in cases 1 to 3 was associated closely with fibrocystic changes. In case 4, cystic changes were located within the fibroadenoma. On tissue sections of all four cases, the cyst contents and 10% to 50% of normal lobule and duct contents stained with mucicarmine, indicating that the cyst contents were the most probable source of mucin in the FNA smears. The presence of pools of mucicarmine-positive material in FNA smears of the breast is not an exclusive feature of mucinous carcinoma; mucicarmine-positive mucin can arise from benign cystic changes as well as from normal lobules and ducts.

NMR study and comparison of the antigenic properties of a peptide recognized by two HIV-1 neutralizing antibodies

Fab-peptide complexes formed between a 15 residue peptide derived from the HIV-1 gp120 V3 loop and two of its cognate monoclonal antibodies, 5023A and 5025A, were studied using isotope-edited solution nuclear magnetic resonance (NMR) techniques. Since these antibodies neutralize HIV-1 virus with different strain specificities, this study was conducted to better understand the nature of these differences. The amide proton and nitrogen NMR resonances of specific residues were used to monitor the backbone of this peptide in these complexes. Three central residues of this peptide ('RAF') were found to be strongly affected by binding to both antibodies. Several other peptide residues were affected by binding to antibody 5023A but not 5025A. The antibody epitopes mapped by NMR are similar to those obtained previously via PEPSCAN at higher pH. One main difference between the PEPSCAN and NMR determined epitopes for 5023A involved two glycine residues of the peptide. By NMR, one of these glycines was more dramatically affected by antibody binding than predicted by PEPSCAN, while the other was much less so.

Oral condyloma acuminatum associated with human papillomavirus and p53 overexpression mimicking cyclosporine effect in a transplant patient

A case of human papillomavirus-associated condyloma acuminatum in the oral cavity, presumed to be fulminant cyclosporine-induced gingival hyperplasia, is reported in a 55-year-old cardiac transplant patient. Approximately 47 months following the transplant, the patient developed severe hyperplasia of the uvula and oral mucosa, resulting in difficulty swallowing. The histopathologic features of the lesion were typical of those of condyloma acuminatum. In situ hybridization of the paraffin-embedded material revealed infection with human papillomavirus types 6/11. This case lends further support to the putative role of long-term cellular immunosuppression in the development of human papillomavirus-associated squamous lesions. In addition, positive staining for p53 protein raises the possibility of concomitant p53 involvement in the pathogenesis of this oral lesion.

Molecular characterization of primary mediastinal B cell lymphoma

Primary mediastinal B cell lymphoma (PMBL) is a diffuse large B cell lymphoma (DLCL) postulated to arise from noncirculating thymic B lymphocytes. Because of its distinctive clinical and morphological features and putative unique cellular origin, PMBL is generally considered a distinct clinicopathological entity. Little is known, however, about the molecular characteristics of PMBL. Therefore, we analyzed 16 PMBLs for molecular alterations involving the bcl-1, bcl-2, bcl-6, c-myc, H-ras, K-ras, N-ras, and p53 genes and for Epstein-Barr virus infection, which are commonly involved in lymphoid neoplasia. Employing a combination of Southern blotting and/or polymerase chain reaction and single-strand conformation polymorphism assays, we detected genetic alterations in 7 of the 16 (44%) PMBLs. Whereas the bcl-6 gene is rearranged in up to 45% of DLCLs, rearrangement of the bcl-6 gene was detected in only 1 of these 16 (6%) PMBLS. Point mutations of the 5' noncoding region of the c-myc gene were demonstrated in 3 other cases (19%), although c-myc gene rearrangements were not seen by Southern blotting. Missense point mutations of the p53 gene were identified in 3 additional PMBLs (19%). Alterations of the bcl-1, bcl-2, or ras genes and evidence of Epstein-Barr virus infection were not observed. In conclusion, a variety of molecular lesions occur in PMBLs and may be involved in their pathogenesis. This molecular genetic pattern bears little resemblance to that known for other B cell malignancies, including DLCL. In particular, the infrequent occurrence of bcl-6 gene rearrangement in PMBLs distinguishes them from other DLCLs of B cell origin, suggesting that PMBLs do not represent a distinct subtype of DLCL.

Some practical aspects of double-resonance techniques in solution-state NMR studies of high-molecular-weight systems

This paper addresses some of the practical issues associated with solution NMR investigations of high-molecular-weight ( > 20 kDa) biomolecules and their complexes. The experimental example of a high-molecular-weight system used here is a 52 kDa Fab/peptide complex. Theoretical as well as experimental aspects of solution NMR techniques employed to study such larger systems are discussed. Specific topics covered include hardware considerations, solvent suppression, and the relative efficiencies of various isotope-edited NMR techniques. Typical NOE methods used to derive structural information on these higher-molecular-weight systems and the scope of structural detail achievable are also examined.

Physical disability among American medical students

The present survey aimed to assess the prevalence and nature of physical disabilities among medical school graduates and to investigate the academic performance of these new physicians with disabilities. A questionnaire was sent to the deans of student affairs of each of the then existing 128 United States and Puerto Rican medical schools, addressing the profiles of students with physical disabilities in the 1987 through 1990 graduating classes. Seventy-seven (60%) United States and Puerto Rican medical schools responded to the questionnaire, of which 67 were able to complete it. A total of 67 students with physical disabilities (40 males and 27 females) were reported. Three of the 67 students were excluded from the study because their conditions did not match our definition of physical disability. The remaining 64 students (38 males and 26 females), ranging from 0 to 10 per school, comprised 0.19% of the 33,138 students who graduated from the 67 medical schools during these 4 academic yr. The disabilities represented by the 64 students encompassed a wide spectrum of etiologies, including neurologic (39%), musculoskeletal (20%), medical-surgical (13%), visual (13%), and auditory (9%) problems. The majority of students with disabilities had above average (36%) to average (48%) academic standings. The actual prevalence of medical students with disabilities might be higher than reported because of the underreporting of the less noticeable types of disabilities.

A novel L23-related gene 40 kb downstream of the imprinted H19 gene is biallelically expressed in mid-fetal and adult human tissues

The closely linked IGF2 and H19 genes on human chromosome 11p15.5 are monoallelically expressed as a result of genomic imprinting and show altered expression in Wilms' tumors (WTs). To map regional imprinting we have sought to isolate additional human genes close to IGF2/H19 and to characterize their allelic expression patterns. Here we report a novel gene, provisionally named L23MRP [L23 (mitochondrial)-related protein], which is oriented 'tail-to-tail' with H19 and is transcribed to within 40 kb of the last H19 exon. L23MRP is expressed biallelically in many mid-fetal and adult human tissues. This gene is also expressed at normal levels in WTs which have lost expression of H19 either via loss of the maternal chromosome 11p15.5 or via an epigenetic pathway involving site-specific DNA hypermethylation. These data indicate that, at least in post-embryonic stages, L23MRP is functionally insulated from the IGF2/H19 imprinted domain.

Image-directed percutaneous biopsy with large-core needles. Comparison of cytologic and histologic findings

Large biopsy needles (18 and 19 gauge) have been reported to yield high-quality tissue cores for reliable histologic diagnosis. In our institution, image-directed percutaneous biopsy specimens obtained with these needles are processed routinely for simultaneous cytologic and histologic analysis. For the present study, we reviewed our experience with 82 such biopsies of the thoracoabdominal region. We examined the value of cytologic analysis as a supplement to histologic analysis of such biopsies in terms of diagnostic yield and sensitivity for detecting malignancy. Among the 82 specimens, material was adequate for histologic diagnoses in 70 (85%) and for cytologic diagnosis in 63 (77%). Combining the histologic and cytologic results increased the diagnostic yield to 93% (76 of 82 specimens). Forty-eight lesions were diagnosed as malignant by either one or both means of analysis. While histologic analysis produced 44 of the 48 positive results (92%), cytologic analysis produced 33 (66%) (P < .05, McNemar's test). Because tissue fragments were selected preferentially for histologic processing, histologic evaluation was more valuable than cytologic evaluation in achieving definitive diagnoses of malignancy. In spite of this bias in preparation technique, malignancy was diagnosed by cytologic analysis alone in 4 of the 48 positive cases (8%). We conclude that the combined approach of histologic and cytologic examination of large-gauge core needle biopsy specimens maximizes the diagnostic yield and sensitivity for detecting malignancy.

A study of appropriateness of acute geriatric admissions and an assessment of the Appropriateness Evaluation Protocol

We studied the appropriateness of admissions to our acute geriatric unit to determine whether they were clinically indicated and to test the Appropriateness Evaluation Protocol (AEP), an instrument previously validated for general hospital admissions. An admission is appropriate according to the AEP if at least 1 of its 16 criteria is met. At the next ward round, a consultant would judge, given the clinical details available on admission, whether the admission was appropriate, regardless of the AEP. All emergency admissions during a three week period were eligible. Of 186 admissions, 146 (78.5%) were available for analysis. The rates of inappropriateness according to consultants and AEP were 13% and 11% respectively. The AEP had a sensitivity of 97%, specificity of 63%, positive and negative predictive values of 95% and 75% respectively. The overall agreement between consultants and AEP was 92% (kappa = 0.62). There are no data on the optimal level of appropriateness but our rate of 87% (89% using the AEP) appears favourable. This study also shows the AEP to be a suitable tool to monitor the appropriateness of acute geriatric admissions.

Gastrointestinal disease in the immunocompromised patient

Gastrointestinal (GI) disease is frequent in all types of immunocompromised patients but occurs with greatest frequency in patients with acquired immunodeficiency syndrome (AIDS). Thus, much of this review deals with human immunodeficiency virus (HIV)-related GI diseases. Gastrointestinal diseases in other immunocompromised patients are compared with those in patients with AIDS. Conditions unique to transplant recipients, such as graft-versus-host disease (GVHD) and posttransplant lymphoproliferative disorders (PTLDs), are discussed separately. We have divided these GI diseases into four main categories: (1) HIV-related inflammatory conditions other than opportunistic infections (HIV-related enteropathy, proctocolitis, and CD8 lymphocytosis); (2) inflammatory conditions unrelated to HIV or opportunistic infections (neutropenic enterocolitis, regional enteritislike enteropathy, and GVHD); (3) opportunistic infections (illnesses caused by herpesvirus, cytomegalovirus, and miscellaneous other viruses; Mycobacterium, Candida, Histoplasma, Cryptococcus, Cryptosporidium, Microsporida, Isospora, Leishmania, Toxoplasma and Strongyloides organisms as well as Pneumocystitis carinii; and (4) neoplasias (Kaposi's sarcoma [KS], AIDS-related non-Hodgkin's lymphoma [NHL], HIV-related Hodgkin's disease [HD], PTLDs, and miscellaneous neoplasms). The prevalence, pathogenesis, clinical manifestations, gross pathological findings, and microscopic features of each disease entity are discussed.

Adnexal tumor and a pigmented nevoid lesion in a benign cystic ovarian teratoma

We describe a case of an unusual adnexal lesion and concurrent collections of dendritic melanocytes of the type occurring in a blue nevus in a mature cystic teratoma of the ovary. To our knowledge, there have been no previous reports of benign skin adnexal tumors in an ovarian dermoid cyst. This rarity would indicate that the cutaneous adnexal tissue in a benign teratoma is not unduly prone to undergo further more-specialized secondary tumorigenesis. The combination of the three benign lesions is therefore probably purely coincidental.

Thyroid hormone deiodination in brain, liver, gill, heart and muscle of Atlantic salmon (Salmo salar) during photoperiodically-induced parr-smolt transformation. II. Outer- and inner-ring 3,5,3'-triiodo-L-thyronine and 3,3',5'-triiodo-L-thyronine (reverse T3) deiodination

Outer-ring deiodinase (ORD) and inner-ring deiodinase (IRD) pathways for 3,5,3'-triiodo-L-thyronine (T3) and 3,3',5'-T3 (reverse T3, rT3) were examined in microsomal fractions of liver, heart, gill, brain, and skeletal muscle of 20-month-old Atlantic salmon induced to undergo parr-smolt transformation (PST) in late February and March by imposing a 16-hr photoperiod. All tissues showed negligible T3ORD activity. T3IRD activity was detected in both the liver (Km = 0.65 nM; Vmax = 15.5 pmol T3 deiodinated.hr-1.mg microsomal protein-1) and brain of smolts, but not in gill, heart, or skeletal muscle. rT3ORD was detected in liver, brain, and muscle, and at very low levels in gill and heart. rT3IRD activity occurred to some extent in all tissues except brain. T3IRD activity changed in brain during PST, and was low in brain and liver of post-smolts examined in late October. We conclude that (i) deiodination of T3 proceeds exclusively through an IRD pathway, which may permit regulation of T3 degradation independently of the ORD pathway responsible for T3 formation; (ii) deiodination of rT3 proceeds mainly through an ORD pathway but rT3IRD activity does occur in some tissues; and (iii) the altered brain T3IRD activity during PST suggests regulation of T3 turnover in the brain at this time.

Phenotypic aberrations of CD3+ and CD4+ cells and functional impairments of lymphocytes at low-level occupational exposure to lead

To study the immunological effects of low-level occupational exposure to lead, we have examined the phenotypic parameters and functional integrity of peripheral blood lymphocytes in a group of firearms instructors and compared the data to those obtained from healthy unexposed controls. Our results indicate that, among individuals with mildly elevated blood lead levels (> 25 micrograms/dl), detrimental effects on the host's immune functions occur. Such dysfunctions are multicellular as to mechanism and dose dependent in nature. The absolute percentage and number of CD3+ and CD4+ cells were significantly reduced, while the values for CD8+ cells were unchanged. Functional integrity of T cells as determined by responses to mitogens was impaired while that of T-cell-dependent B-lymphocyte function appeared to be within normal range at all stages of maturation. These data suggest the presence of a defective feedback loop which regulates T-cell-dependent functions and cell-to-cell cooperation. Furthermore, the marked deficiency in MLC responses that was also observed suggests that the adverse effect of lead may be due to its high affinity for the TCR and HLA-DR surface receptors thereby interfering with antigen processing from monocytes to T lymphocytes.

Conformation and dynamics of an Fab'-bound peptide by isotope-edited NMR spectroscopy

The dynamics and conformation of the peptide antigen MHKDFLEKIGGL bound to the Fab' fragment of the monoclonal antipeptide antibody B13A2, raised against a peptide from myohemerythrin, have been investigated by isotope-edited NMR techniques. The peptides were labeled with 15N (98%) or 13C (99%) at the backbone of individual amino acid residues. Well-resolved amide proton and nitrogen backbone resonances were obtained and assigned for eight of the 12 residues of this bound peptide. Significant resonance line width and chemical shift differences were observed. The 15N and 1H line width variations are attributed to differential backbone mobilities among the bound peptide residues which are consistent with the previously mapped epitope of this peptide antigen. Local structural information was obtained from isotope-directed NOE studies. The approximate distances associated with the experimental NOEs were estimated on the basis of a theoretical NOE analysis involving the relative integrated intensities of the NOE and source peaks. In this way, the sequential NH-NH NOEs obtained for seven of the Fab'-bound peptide residues were shown to correspond to interproton separations of approximately 3 A or less. Such short distances indicate that the backbone dihedral angles of these residues are in the alpha rather than the beta region of phi,psi conformational space; the peptide most likely adopts a helical conformation from F5 to G11 within the antibody combining site. The significance of these results with respect to the type and extent of conformational information obtainable from studies of high molecular weight systems is discussed.

Understanding digoxin use in the elderly patient

There are many disease states in the elderly that mandate the use of drugs with extremely narrow therapeutic indexes and potentially fatal toxicity. Digoxin is one example of such drugs. It is extensively used for the treatment of congestive heart failure of diverse origin and of cardiac arrhythmias of supraventricular origin. Aging can produce changes in essentially all organ systems, which as a whole render geriatric patients particularly vulnerable to the toxic effects of digoxin. Among all age-related pharmacokinetic and pharmacodynamic changes, declining renal function is perhaps the most important factor that must be considered. This often means a significantly less efficient renal digoxin clearance, which necessitates a reduction in dosage. The geriatric population tends to consume more drugs and are more at risk for undesirable multidrug interactions than their younger counterparts. To name a few, quinidine, verapamil, amiodarone, and non-K(+)-sparing diuretics are notorious for predisposing the patient to digoxin toxicity when administered concurrently with digoxin. Therefore, digoxin must be prescribed to elderly patients with great judiciousness, with careful interpretation of serum digoxin assay, and due consideration of its intrinsic limitations.

Antigen-antibody interactions: an NMR approach

With recent advances in methodology, it now appears that NMR can be used at an unprecedented level of sophistication to obtain new insights into the solution structure and dynamics of the antibody combining site, both free and in its complex with antigen. Most promising in this regard is the Fv fragment (molecular weight approximately 25 kD) which can be produced by genetic engineering in a form suitable for NMR studies. Isotopic labeling is required to make specific resonance assignments. NMR can also provide information on the conformational preferences of immunogenic peptides and can be used to probe the conformation and dynamics of peptides (appropriately labeled with 13C or 15N) bound to the Fab fragment (molecular weight approximately 50 kD) of antipeptide antibodies.

Isotope-edited NMR studies of Fab'-peptide complexes

Complexes formed between a monoclonal anti-peptide Fab' and its complementary 15N-labeled peptide were studied primarily by isotope-edited nuclear magnetic resonance (NMR) techniques. The monoclonal antibodies used were raised against peptides corresponding to residues 69-87 of the protein myohemerythrin. The complexes studied correspond to Fab' bound to the synthetic peptide, MHKDFLEKIGGL-NH2 (residues 76-87 of myohemerythrin) labeled with 15N at various amides. The combined approach of using specifically 15N-labeled peptides and reverse-detection solution NMR techniques has allowed us to monitor selectively the peptide component of the Fab'-peptide complexes studied. Through the use of these techniques, we have been able to directly observe the resonances of the bound peptide, as well as distinguish between free and bound peptide resonances in situations when excess peptide is present. NMR titrations of the Fab' with antigen have shown that there is one site to which the peptide strongly binds. The NMR parameters of the various residues examined thus far have been quite distinctive from each other, reflecting the ability of these techniques to detect differences in the local environment of the individual residues. Differences with respect to these parameters among the various residues may be related to the overall antigenic properties of the peptide.

Structure and dynamics of the Pf1 filamentous bacteriophage coat protein in micelles

The major coat protein of filamentous bacteriophage adopts its membrane-bound conformation in detergent micelles. High-resolution 1H and 15N NMR experiments are used to characterize the structure and dynamics of residues 30-40 in the hydrophobic midsection of Pf1 coat protein in sodium dodecyl sulfate micelles. Uniform and specific-site 15N labels enable the immobile backbone sites to be identified by their 1H/15N heteronuclear nuclear Overhauser effect and allow the assignment of 1H and 15N resonances. About one-third of the amide N-H protons in the protein undergo very slow exchange with solvent deuterons, which is indicative of sites in highly structured environments. The combination of results from 1H/15N heteronuclear correlation, 1H homonuclear correlation, and 1H homonuclear Overhauser effect experiments assigns the resonances to specific residues and demonstrates that residues 30-40 of the coat protein have a helical secondary structure.

Plasma estradiol, testosterone, and progesterone levels during the ovulatory cycle of the skate (Raja erinacea)

Amounts of estradiol, testosterone, and progesterone in plasma were measured during the reproductive cycle of female Raja erinacea. Estradiol titers correlated directly with follicle size in females undergoing ovarian recrudescence, while highest concentrations were found in females with preovulatory follicles. These data indicate that as follicles grow, their steroidogenic capacity increases. In mature, nonspawning females, titers of estradiol and testosterone varied markedly. Progesterone was not detected in peripheral plasma of skates that did not produce eggs during the observation period. In females producing eggs, estradiol and testosterone predominated during the follicular phase of each spawning cycle. While estradiol and testosterone were elevated, progesterone was not detectable in the peripheral circulation. As ovulation and formation of capsules approached, plasma estradiol and testosterone declined to near baseline levels. Circulating progesterone rose sharply two days before encapsulation of ovulated eggs and remained elevated for only two days. On the day of encapsulation, concentrations of plasma progesterone had fallen to nearly baseline levels. Progesterone titers remained low throughout egg retention and oviposition. These measurements demonstrate that progesterone titers are elevated at specific times during the reproductive cycle of the skate and clearly suggest that progesterone is critically involved in events occurring at ovulation, encapsulation, and possibly oviposition.

High frequency of immune dysfunctions in asbestos workers and in patients with malignant mesothelioma

We have examined the primary immune responses, the numbers of total T (T11+) cells, T-helper (T4+) cells, T-suppressor (T8+) cells, and natural killer (NK) (Leu7+) cells, in 118 healthy control subjects and compared the data to those obtained from 20 patients with clinically diagnosed malignant mesothelioma and 375 long-term asbestos workers without neoplasia. The absolute numbers of total T (T11+) and T-helper (T4+) cells were normal in asbestos workers without neoplasia but were significantly reduced in patients with mesothelioma. T-suppressor (T8+) cells, on the other hand, remained unchanged in the patients but were significantly elevated among the asbestos workers. This resulted in a marked reduction in T-helper (Th) to T-suppressor (Ts) ratios in mesothelioma patients and in asbestos workers. Seventy percent of the mesothelioma patients (14 of 20) had significantly depressed NK-cell activity which could be augmented but not normalized by coincubation in patients' peripheral blood lymphocytes (PBL) with interferon (IFN). Among the asbestos workers three distinctive subgroups could be identified: heightened (H-NK), normal (N-NK), and low (L-NK) NK activity. The NK activity of the L-NK group could be stimulated but not normalized by coincubation with IFN, a finding closely resembling that in malignant mesothelioma patients. Phenotyping of the circulating NK cells revealed a unique Leu7+ subset in increased numbers with a brightly fluorescent property in stable mesothelioma patients with relatively stable or slowly progressive disease and in more than 30% of the asbestos workers.(ABSTRACT TRUNCATED AT 250 WORDS)

Protection against infection with Neisseria meningitidis group B serotype 2b by passive immunization with serotype-specific monoclonal antibody

Hybridomas derived from mice immunized with Neisseria meningitidis serogroup B serotype 2b (B,2b) outer membrane preparations produced monoclonal antibodies (MAbs) specific for major outer membrane proteins of classes 1, 2, and 5. The MAbs were examined by enzyme-linked immunosorbent assay against a selected panel of seven strains of N. meningitidis (B,2b) of different sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns, a serotype 2a, and a nontypable strain. The five MAbs selected were all bactericidal and of different immunoglobulin subclasses. None of the MAbs reacted with other bacterial strains in a dot-enzyme immunoassay. The corresponding antigenic determinant for each MAb was localized on a specific outer membrane protein by immunoblotting of sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns of major outer membrane proteins. MAbs M5-11 and M5-30 bound to the class 2 protein and were serotype 2b specific. MAb M2-20 bound to the class 1 protein, and MAbs M5-16 and M5-19 bound to the class 5 protein. A mouse model of infection was established whereby a local infection progressed to lethal bacteremia over 3 days, and 50% of the animals were killed with an intraperitoneal injection of 10 meningococci plus 4% mucin and 1.6% hemoglobin. The ability of the MAbs to provide passive protection against experimental infection with N. meningitidis (B,2b) was examined. Both serotype-specific MAbs M5-11 and M5-30 were highly protective even though they were of different immunoglobulin subclasses. The class 5-specific MAb offered no protection, while the class 1-specific MAb gave limited protection. It may therefore be possible to provide protection against serotype 2b infection by using as vaccine the class 2 serotype-specific surface-exposed outer membrane protein epitopes defined by MAb M5-11 or M5-30.

One- and two- dimensional 15N/1H NMR of filamentous phage coat proteins in solution

High resolution 15N NMR studies of proteins in solution can be performed efficiently by combining the use of isotopically enriched proteins and pulse sequences that generate polarization transfer from protons and result in two-dimensional heteronuclear chemical shift correlation spectra. The coat proteins of the filamentous bacteriophages fd and Pf1 solubilized in detergent micelles give one- and two- dimensional NMR spectra with resolved resonances for nearly all of the nitrogen sites in the proteins. The resonances from the amide sites with slowly exchanging protons can be obtained as a subset of the resonances of all amide sites by comparing the spectra of proteins in D2O and H2O solutions at pH = 4.0.

Immunopotentiation of impaired lymphocyte functions in vitro by isoprinosine in prodromal subjects and AIDS patients

Immunomodulative actions of isoprinosine were tested in 100 prodromal homosexual males and 23 patients who have been diagnosed with AIDS. All subjects showed reduced T helper cells although T suppressor cell counts were normal. Proliferative responses, particularly T cell-dependent B cell function, were severely impaired in prodromal and AIDS subjects. Upon co-cultivation of their lymphocytes with isoprinosine, significant upward modulation, and in some cases, normalization, of lymphocyte functions as monitored by PHA- and PWM-induced blastogenesis was achieved in prodromal subjects. Similar degrees of modulation but not normalization of lymphocyte functions were observed in patients with severe symptoms of AIDS.

Functional integrity of T, B, and natural killer cells in homosexual subjects with prodromata and in patients with AIDS

We have examined the numbers of the total T (T11+) cells, T-helper (T4+) cells, T-suppressor (T8+) cells, NK cells (Leu7+), and the functional integrity of T, B, and NK cells in healthy male heterosexuals and compared the data to those obtained from AIDS patients and male homosexuals at risk. The absolute number of total T (T11+) and T-helper (T4+) cell populations were significantly reduced among most of the asymptomatic homosexual males and even more decreased in the AIDS patients. By contrast, the absolute numbers of T-suppressor cells (T8) remained virtually unaltered in the three study populations. The absolute numbers of circulating natural killer cells were similar in the controls and the homosexual subjects, but significantly reduced in the AIDS patients. Proliferative responses to T-cell mitogen (PHA) and T-cell dependent B-cell mitogen (PWM) were severely impaired in prodromal subjects and more so in the AIDS group. Response to PWM was unrelated to the total number of T-suppressor cells, but was associated with a significant decrease in T-helper cell number. Furthermore, all AIDS patients exhibited a significantly depressed NK-cell activity that could not be normalized by addition of alpha IFN or IL-2 and in most cases correlated with the reduced absolute number of NK (Leu7+) cells as well as T-helper cells (T4) and T4/T8 ratios. Three distinctive subgroups with normal (N-NK), significantly heightened (H-NK), and markedly lowered (L-NK) NK activity could be readily identified among the homosexual male population at risk. The N-NK and L-NK groups displayed marginal to no response to in vitro treatment with alpha IFN and interleukin-2. The NK-cell activity, however, in the H-NK group was moderately to strongly inhibited by inclusion of the two immunomodifiers.