Fluorescence and Multiphoton Imaging for Tissue Characterization of a Model of Postmenopausal Ovarian Cancer

BACKGROUND AND OBJECTIVES

To determine the efficacy of targeted fluorescent biomarkers and multiphoton imaging to characterize early changes in ovarian tissue with the onset of cancer.

STUDY DESIGN/MATERIALS AND METHODS

A transgenic TgMISIIR-TAg mouse was used as an animal model for ovarian cancer. Mice were injected with fluorescent dyes to bind to the folate receptor α, matrix metalloproteinases, and integrins. Half of the mice were treated with 4-vinylcyclohexene diepoxide (VCD) to simulate menopause. Widefield fluorescence imaging (WFI) and multiphoton imaging of the ovaries and oviducts were conducted at 4 and 8 weeks of age. The fluorescence signal magnitude was quantified, and texture features were derived from multiphoton imaging. Linear discriminant analysis was then used to classify mouse groups.

RESULTS

Imaging features from both fluorescence imaging and multiphoton imaging show significant changes (P < 0.01) with age, VCD treatment, and genotype. The classification model is able to classify different groups to accuracies of 75.53%, 69.53%, and 86.76%, for age, VCD treatment, and genotype, respectively. Building a classification model using features from multiple modalities shows marked improvement over individual modalities.

CONCLUSIONS

This study demonstrates that using WFI with targeted biomarkers, and multiphoton imaging with endogenous contrast shows promise for detecting early changes in ovarian tissue with the onset of cancer. The results indicate that multimodal imaging can provide higher sensitivity for classifying tissue types than using single modalities alone. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Dual inhibition of SRC and Aurora kinases induces postmitotic attachment defects and cell death

Increased activity of SRC family kinases promotes tumor invasion and metastasis, and overexpression of the mitotic regulator Aurora kinase A (AURKA) drives tumor aneuploidy and chromosomal instability. These functions nominate SRC and AURKA as valuable therapeutic targets for cancer, and inhibitors for SRC and Aurora kinases are now being used in the clinic. In this study, we demonstrate potent synergy between multiple inhibitors of Aurora and SRC kinases in ovarian and colorectal cancer cell lines, but not in normal ovarian epithelial cell lines. Combination of Aurora and SRC inhibitors selectively killed cells that have undergone a preceding aberrant mitosis, and was associated with a postmitotic reattachment defect, and selective removal of aneuploid cell populations. Combined inhibition of Aurora kinase and SRC potentiated dasatinib-dependent loss of activated (Y(416)-phosphorylated) SRC. SRC and AURKA share a common interaction partner, NEDD9, which serves as a scaffolding protein with activities in cell attachment and mitotic control, suggesting SRC and AURKA might interact directly. In vitro, we observed physical interaction and mutual cross-phosphorylation between SRC and AURKA that enhanced SRC kinase activity. Together, these findings suggest that combination of SRC and Aurora-targeting inhibitors in the clinic may be a productive strategy.

Translational research in ovarian cancer: a must

Ovarian cancer discovered at late clinical stage continues to be a fatal disease. It seems self-evident that if we are to make an impact on the survival of advanced ovarian cancer patients, we must begin to understand the disease more completely. This should improve the diagnosis of the disease at an early stage when it is curable by surgery or develop better/targeted drug treatments. Modern molecular techniques have provided insights into many of the molecular changes that occur when ovarian cancer develops, but one must understand that changes seen in this way can only be said to correlate with disease. It would be helpful to have a way to test candidate changes for causality. In many cancer types, genetically engineered animals are beginning to be used for this purpose and as a means to study the disease process in greater detail. To date, there has been no way to study ovarian cancer by this means. Efforts to model human ovarian cancer have been delayed by a general lack of understanding both of the disease process in humans and of the cells widely believed to be the precursors of epithelial ovarian cancer, the ovarian surface epithelial (OSE) cells. Here, we present recent progress in modeling ovarian cancer using genetically modified mice.

Translational research in ovarian cancer: a must

Ovarian cancer discovered at late clinical stage continues to be a fatal disease. It seems self-evident that if we are to make an impact on the survival of advanced ovarian cancer patients, we must begin to understand the disease more completely. This should improve the diagnosis of the disease at an early stage when it is curable by surgery or develop better/targeted drug treatments. Modern molecular techniques have provided insights into many of the molecular changes that occur when ovarian cancer develops, but one must understand that changes seen in this way can only be said to correlate with disease. It would be helpful to have a way to test candidate changes for causality. In many cancer types, genetically engineered animals are beginning to be used for this purpose and as a means to study the disease process in greater detail. To date, there has been no way to study ovarian cancer by this means. Efforts to model human ovarian cancer have been delayed by a general lack of understanding both of the disease process in humans and of the cells widely believed to be the precursors of epithelial ovarian cancer, the ovarian surface epithelial (OSE) cells. Here, we present recent progress in modeling ovarian cancer using genetically modified mice.

Ovarian epithelial cell lineage-specific gene expression using the promoter of a retrovirus-like element

We have isolated 462 bp of sequence termed ovarian-specific promoter 1 (OSP-1) that is part of a retrovirus-like element specifically expressed in the rat ovary. We have evaluated the ability of OSP-1 to activate gene expression in normal and neoplastic cell lines derived from the ovaries of rats and women. We have found that there was marked specificity in the ability of OSP-1 to drive reporter gene expression in an ovarian epithelial cell lineage manner. The expression of herpes simplex virus thymidine kinase (HSV-TK) under OSP-1 control was sufficiently ovarian cancer cell line specific to render ganciclovir approximately 50-fold more toxic in the A2780 human ovarian cancer cell line compared with clones of the HCT-116 and HT-29 colon cancer cell lines. Furthermore, ganciclovir had marked antitumor efficacy in vivo in severe combined immunodeficient mice bearing A2780OSP-1-HSV-TK as a s.c. xenograft. We suggest that these data support the use of OSP-1 as a tool to provide specificity to the gene therapy of ovarian cancer and to drive ovarian-specific oncogene expression for the creation of transgenic mouse models of ovarian cancer.

Loss of fhit expression in invasive cervical carcinomas and intraepithelial lesions associated with invasive disease

Allelic losses involving chromosome 3p are frequently observed in cervical cancers. Deletion mapping studies of primary cervical carcinomas have localized common regions of deletion to 3p14.2 and 3p21. The candidate tumor suppressor gene FHIT has been mapped to 3p14.2, and previous studies have demonstrated reduced or aberrant FHIT transcripts and reduced or absent Fhit protein expression in a large percentage of cervical cancer-derived cell lines and primary cervical carcinomas. To expand these observations to preinvasive cervical epithelial lesions and to determine whether loss of Fhit protein expression might be associated with tumor progression, immunohistochemical methods were used to examine Fhit expression in 95 invasive cervical carcinomas, 33 high-grade squamous intraepithelial lesions (HSILs) associated with concurrent invasive cancer, 38 HSILs unassociated with invasive cancer, 24 low-grade squamous intraepithelial lesions, and 22 normal cervix samples. All normal cervical epithelia and low-grade squamous intraepithelial lesions exhibited diffuse cytoplasmic immunostaining of moderate to strong intensity. Fhit protein expression was markedly reduced or absent in 67 of 95 (71%) invasive cancers, 17 of 33 (52%) HSILs associated with invasive cancer, and 8 of 38 (21%) HSILs without associated invasive cancer. The results confirm that Fhit protein expression is reduced or absent in the majority of cervical carcinomas and suggest that loss of Fhit expression often accompanies cervical tumor progression. Moreover, absent or reduced Fhit protein is observed at a significantly higher frequency in HSILs associated with progression to invasive cancer than in HSILs with unknown risk for progression (P = 0.012). These findings suggest that loss of Fhit expression in HSILs could serve as a useful marker of high-grade preinvasive lesions that have an increased likelihood of progression to invasive carcinoma.

Restored expression of fragile histidine triad protein and tumorigenicity of cervical carcinoma cells

BACKGROUND

Allelic losses in the short arm of chromosome 3 are common in cervical carcinomas. The fragile histidine triad (FHIT) gene at chromosome region 3p14.2 is a candidate tumor suppressor gene that may play a role in cervical tumorigenesis. We and others have identified aberrant FHIT transcripts and frequent loss of Fhit protein expression in primary cervical cancers and high-grade noninvasive lesions but not in normal cervical tissues. The altered expression of FHIT may be due to somatic mutations or integration of human papillomavirus DNA at the FHIT locus. The purpose of this study was to determine whether ectopic expression of Fhit can suppress the tumorigenic properties of cervical cancer cells.

METHODS

We employed infection with recombinant retroviruses as well as transfection of plasmid DNA to restore Fhit protein expression in cervical cancer cell lines lacking full-length FHIT transcripts and endogenous Fhit protein. The effects of Fhit expression on tumor cell morphology, anchorage-independent growth, and tumorigenicity in nude mice were examined.

RESULTS

Stable overexpression of Fhit had no discernible effect on the tumorigenic properties of two cervical carcinoma cell lines or on a lung carcinoma cell line previously reported by others to be suppressed for tumorigenicity by Fhit.

CONCLUSIONS

Restoration of Fhit expression does not suppress anchorage-independent growth or tumorigenicity of cervical carcinoma cell lines. However, it remains possible that FHIT inactivation may be important early in cervical tumor progression or that FHIT may suppress tumorigenesis in ways distinct from those measured by the assays employed in this study.

Somatic mutations in the STK11/LKB1 gene are uncommon in rare gynecological tumor types associated with Peutz-Jegher's syndrome

Peutz-Jegher's syndrome (PJS) is a rare autosomal dominant disorder characterized by mucocutaneous pigmentation, hamartomatous polyposis, and predisposition to benign and malignant tumors of the gastrointestinal tract, breast, ovary, uterine cervix, and testis. Germline-inactivating mutations in one allele of the STK11/LKB1 gene at chromosome 19p13.3 have been found in most PJS patients. Although ovarian sex cord tumors with annular tubules (SCTATs) and minimal deviation adenocarcinomas (MDAs) of the uterine cervix are very rare in the general population, both tumor types occur with increased frequency in women with PJS. An earlier report indicated that the 19p13.3 region containing the STK11 gene was affected by loss of heterozygosity (LOH) in nearly 50% of MDAs of the uterine cervix. We investigated the role of STK11 mutations and LOH of the 19p13.3 region in two PJS-associated SCTATs and in five SCTATs and eight MDAs of the uterine cervix, which occurred in patients lacking features of PJS (referred to here as "sporadic" cases). Germline mutations in the STK11 gene, accompanied by LOH of markers near the wild-type STK11 allele, were found in the two PJS-associated SCTATs. Somatic mutations in the coding region of STK11 were not found in any of the sporadic SCTATs or MDAs studied, although LOH of the 19p13.3 region was seen in three of eight MDAs. Our findings indicate that STK11, like other tumor suppressor genes, is affected by biallelic inactivation in gynecological tumors of PJS patients. In addition, although LOH of the 19p13.3 region was seen in sporadic MDAs, somatic STK11 mutations are rare. A yet-to-be-defined tumor suppressor gene in the 19p13.3 region may be the specific target of inactivation in these tumors.

Somatic mutations of the PPP2R1B candidate tumor suppressor gene at chromosome 11q23 are infrequent in ovarian carcinomas

Previous studies have demonstrated frequent allelic losses of distal chromosome 11q in ovarian carcinomas. The tumor suppressor gene(s) presumably targeted by these losses have not yet been identified. PPP2R1B is a candidate tumor suppressor gene at 11q23 that has recently been shown to be mutated in a subset of colorectal and lung cancers. We evaluated 5 ovarian carcinoma cell lines and 27 primary ovarian carcinomas for allelic losses of 11q23 and for mutations in the open reading frame of PPP2R1B. We also evaluated the primary tumors for allelic losses at 17p13, another chromosomal region frequently affected by losses of heterozygosity (LOH) in ovarian cancers. 11q23 and 17p13 allelic losses were identified in 25% and 74% of the carcinomas, respectively. No mutations within PPP2R1B coding sequences were found. These findings indicate that mutations of the PPP2R1B gene are infrequent in ovarian cancer and that deletions affecting the distal portion of chromosome 11q in ovarian cancer likely target inactivation of other genes.

Molecular genetic evidence supporting the clonality and appendiceal origin of Pseudomyxoma peritonei in women

Pseudomyxoma peritonei (PMP) is a poorly understood condition characterized by mucinous ascites and multifocal peritoneal mucinous tumors. Women with PMP often have mucinous tumors involving both the appendix and the ovaries. Several previous histopathological and immunohistochemical studies of PMP have suggested that most, if not all, cases of PMP in women are derived from mucinous adenomas of the appendix rather than from primary ovarian tumors. A few studies of the molecular genetics of PMP have been recently reported. However, these studies analyzed only a small number of cases and some included a heterogeneous group of mucinous tumors, including both benign and malignant appendiceal and ovarian tumors. We analyzed K-ras mutations and allelic losses of chromosomes 18q, 17p, 5q, and 6q in a substantial number of morphologically uniform cases of PMP with synchronous ovarian and appendiceal tumors as well as in appendiceal mucinous adenomas (MAs) and ovarian mucinous tumors of low malignant potential (MLMPs) unassociated with PMP. Each of the 16 PMP cases (100%) analyzed demonstrated identical K-ras mutations in the appendiceal adenoma and corresponding synchronous ovarian tumor. K-ras mutations were identified in 11 of 16 (69%) appendiceal MAs unassociated with PMP and in 12 of 16 (75%) ovarian MLMPs unassociated with PMP. Two PMP cases showed identical allelic losses in the matched ovarian and appendiceal tumors. A discordant pattern of allelic loss between the ovarian and appendiceal tumors at one or two of the loci tested was observed in six PMP cases. In all but one instance, LOH was observed in the ovarian tumor, whereas both alleles were retained in the matched appendiceal lesion, suggesting tumor progression in a secondary (metastatic) site. Our findings strongly support the conclusion that mucinous tumors involving the appendix and ovaries in women with PMP are clonal and derived from a single site, most likely the appendix.

Molecular genetic alterations in radiation-induced astrocytomas

Astrocytic tumors occasionally arise in the central nervous system following radiotherapy. It is not clear if these gliomas represent a unique molecular genetic subset. We identified nine cases in which an astrocytoma arose within ports of previous radiation therapy, with total doses ranging from 2400 to 5500 cGy. Irradiated primary lesions included craniopharyngioma, pituitary adenoma, Hodgkin's lymphoma, ependymoma, pineal neoplasm, rhabdomyosarcoma, and three cases of lymphoblastic malignancies. Patients ranged from 9 to 60 years of age and developed secondary tumors 5 to 23 years after radiotherapy. The 9 postradiation neoplasms presented as either anaplastic astrocytoma (3 cases) or glioblastoma multiforme (6 cases). Two of the latter contained malignant mesenchymal components. We performed DNA sequence analysis, differential polymerase chain reaction (PCR), and quantitative PCR on DNA from formalin-fixed, paraffin-embedded tumors to evaluate possible alterations of p53, PTEN, K-ras, EGFR, MTAP, and p16 (MTS1/CDKN2) genes. By quantitative PCR, we found EGFR gene amplification in 2 of 8 tumors. One of these demonstrated strong immunoreactivity for EGFR. Quantitative PCR showed chromosome 9p deletions including p16 tumor suppressor gene (2 of 7 tumors) and MTAP gene (3 of 7). Five of 9 tumors demonstrated diffuse nuclear immunoreactivity for p53 protein. Sequencing of the p53 gene in these 9 cases revealed a mutation in only one of these cases, a G-to-A substitution in codon 285 (exon 8). Somewhat unexpectedly, no mutations were identified in PTEN, a commonly altered tumor suppressor gene in de novo glioblastoma multiformes. Unlike some radiation-induced tumors, no activating point mutations of the K-ras proto-oncogene or base pair deletions of tumor suppressor genes were noted. These radiation-induced tumors are distinctive in their high histological grade at clinical presentation. The spectrum of molecular genetic alterations appears to be similar to that described in spontaneous high grade astrocytomas, especially those of the de novo type.

Atypical immature metaplasia (AIM) of the cervix: is it related to high-grade squamous intraepithelial lesion (HSIL)?

Atypical immature metaplasia (AIM) is a poorly characterized cervical lesion with uncertain biological and clinical significance. AIM shares some, but not all, morphological features of squamous intraepithelial lesions (SILs). SILs are characterized by human papillomavirus (HPV) positivity and increased cellular proliferation, but these features have not been fully evaluated in AIM. Genomic DNA was extracted from 27 microdissected cervical biopsy specimens diagnosed as AIM. HPV DNA was detected by polymerase chain reaction (PCR), using two different sets of L1 gene consensus primers. HPV types were identified by sequence analysis of PCR products and comparison with published HPV sequences. The cell proliferation index was assessed by immunohistochemical staining for Ki-67 (MIB-1) antigen and expressed as the percentage of Ki-67-positive cells. Comparison groups included normal cervix (n = 10) and low-grade (LSILs, n = 19) and high-grade squamous intraepithelial lesions (HSILs, n = 11). Intermediate- or high-risk HPV DNA was detected in 67% (18 of 27) of AIM cases. Low-risk HPV DNA was not detected in any of the specimens. The Ki-67 index in AIM (mean, 33.0 +/- 20.3; median, 29) was comparable to that of LSILs (mean, 21.4 +/- 4.6; median, 21) and was significantly higher than that of normal cervix (mean, 11.0 +/- 2.1; median, 11) (P< .01) and lower than that of HSILs (mean, 60.4 +/- 13.2; median, 60) (P < .01). Of the cases with available follow-up, HPV-positive AIMs were significantly more likely to have a concurrent or subsequent diagnosis of typical HSIL (12 of 15, 80%) than HPV-negative AIMs (one of six, 45%) (P = .014). The wide range of Ki-67 indices and variable HPV status in AIM suggest that AIM represents a heterogeneous group of lesions including bona fide HSILs (high-risk HPV-positive, high Ki-67 index), antecedents (precursors?) of HSILs (high-risk HPV-positive, low to moderate Ki-67 index), and benign reactive conditions (HPV-negative, variable Ki-67 index). HPV testing may be useful in the assessment of atypical epithelial proliferations of the cervix for which a diagnosis of AIM is considered.

A sandwich type acridinium-linked immunosorbent assay (ALISA) detects soluble ErbB1 (sErbB1) in normal human sera

The epidermal growth factor receptor (ErbB1) is overexpressed in various human tumor-derived cell lines and neoplasms, where it is believed that receptor dysregulation plays a role in oncogenic transformation and tumor progression. In addition to the ErbB1 holoreceptor, numerous studies demonstrate that cells synthesize soluble or secreted forms of ErbB1, i.e., sErbB1. Overexpression of ErbB1 in a variety of tumors has led us to hypothesize that sErbB levels also may be altered during oncogenesis, tumor progression, and/or metastasis; and that these molecules may be useful tumor biomarkers. To address this hypothesis we have developed an acridinium-linked immunosorbent assay (ALISA) specific for the extracellular domain of ErbB1 that can be used to quantify the levels of sErbB1 molecules in body fluids and conditioned culture media. This assay can also detect full-length ErbB1 in cell and tissue extracts. Our ALISA is characterized by high sensitivity (intra-assay LLD < 1 fmol/ml), a broad linear range (approximately 1 to 4000 fmol/ml), and good reproducibility (CVs < 10%). Specificity experiments show that this ALISA detects p170 ErbB1 and soluble forms of ErbB1 that embody extracellular subdomains I through IV, but not forms of sErbB1 lacking subdomain IV. Our ALISA does not detect full-length ErbB2, ErbB3, or ErbB4; or p105 soluble ErbB2. We report that serum sErbB1 levels of healthy women (median = 3716 fmol/ml), ranging in age from 43 to 76 years, differ significantly from those of healthy men (median = 24,512 fmol/ml), ranging in age from 25 to 79 years. Additional analyses do not indicate that serum sErbB1 levels change with age in either healthy men or women. Immunoprecipitation experiments show that monoclonal antibodies specific for extracellular epitopes of ErbB1 completely neutralize the detection of sErbB1 in normal human sera by ALISA. Finally, we show by immunoprecipitation and Western immunoblot analyses with monoclonal antibodies specific for the extracellular domain of ErbB1 that normal human female and male sera contain a approximately 110-kDa protein. We conclude that our ALISA is measuring the relative levels of this p110 sErbB1 analog in normal human sera. Our ALISA, therefore, should be useful for measuring the levels of ErbB1 and sErbB1 molecules in tumor biopsy specimens and body fluids, respectively, and for determining whether sErbB1, like ErbB1, is a useful tumor biomarker.

Comparison between extradural infusion of ropivacaine or bupivacaine for the prevention of postoperative pain after total knee arthroplasty

We have compared the analgesia and motor block produced by extradural infusions of ropivacaine and bupivacaine after total knee arthroplasty. Fifty-two patients received 8 ml h1 of either 0.2% ropivacaine or 0.2% bupivacaine by extradural infusion for 24 h after operation. Analgesia was assessed by postoperative visual analogue scale (VAS) and morphine consumption. At rest these were low in both groups; median VAS was 0-13.3 mm for the ropivacaine group and 0-0.5 mm for the bupivacaine group. Over the 24 h of the infusion, the estimated (ropivacaine bupivacaine) difference in wound pain at rest was 5.6 mm (P = 0.017) and on passive movement 11.6 mm (P = 0.016). Median morphine consumption was 30.7 mg in the ropivacaine group and 20.5 mg in the bupivacaine group. In the ropivacaine group, 50% of patients compared with 19% in the bupivacaine group had no motor block 2 h after operation, increasing to 88% for ropivacaine and 56% for bupivacaine by 24 h. Bupivacaine produced significantly more frequent and intense motor block over the 24 h (P = 0.015).

Loss of FHIT expression in cervical carcinoma cell lines and primary tumors

Allelic deletions involving the short arm of chromosome 3 (3p13-21.1) have been observed frequently in cervical carcinomas. Recently, a candidate tumor suppressor gene, FHIT (Fragile Histidine Triad), was cloned and mapped to this chromosomal region (3p14.2). Abnormal FHIT transcripts have been identified previously in a variety of tumor cell lines and primary carcinomas, although their significance and the molecular mechanisms underlying their origin remain incompletely defined. In addition, integration of human papillomavirus DNA has been identified at a fragile site (FRA3B) within the FHIT locus in cervical cancer. These observations motivated us to evaluate FHIT mRNA and protein expression in cervical cancer cell lines, primary cervical carcinomas, and normal tissues. Transcripts of the expected size and sequence were the predominant species identified by reverse transcription (RT)-PCR in cultured keratinocytes and all normal tissues evaluated. In contrast, aberrant FHIT transcripts were readily demonstrated in 6 of 7 cervical carcinoma cell lines and 17 of 25 (68%) primary cervical carcinomas. Northern blot analyses demonstrated reduced or absent FHIT expression in the cervical carcinoma cell lines, particularly those with aberrant RT-PCR products. Immunohistochemical analysis of Fhit expression in cervical tissues revealed strong immunoreactivity in nonneoplastic squamous and glandular cervical epithelium and marked reduction or loss of Fhit protein in 25 of 33 (76%) primary cervical carcinomas. In those cervical cancer cell lines and primary tumors with exclusively aberrant or absent FHIT transcripts by RT-PCR, Fhit protein expression was always markedly reduced or absent. The frequent alterations in FHIT expression in many cervical carcinomas, but not in normal tissues, suggest that FHIT gene alterations may play an important role in cervical tumorigenesis.

Expression of HPV16 E6 or E7 increases integration of foreign DNA

In most invasive cervical carcinomas, high-risk human papillomavirus (HPV) DNA is integrated into the host genome, while in pre-invasive cervical lesions the viral genome is typically maintained exclusively as an episome. In contrast, integration of low-risk HPV DNA is rare, as is the association of low-risk HPVs with carcinomas. High-risk HPV integration is associated with a selective growth advantage of affected cells, and hence, integration is likely to be an important genetic alteration contributing to cervical tumor progression. Expression of high-risk, but not low-risk, HPV E6 or E7 proteins disrupts the p53-dependent G1 arrest that cells normally display in response to DNA damage. Absence of this cell cycle checkpoint may predispose cells containing high-risk HPVs to genetic instability and to the accumulation of the genetic alterations that appear to be required for HPV-associated cervical tumor progression. We hypothesized that integration of high-risk HPV DNA into the host cell genome may be facilitated by E6- and/or E7-mediated disruption of the normal DNA damage response pathway. To test this hypothesis, we assessed the integration frequency of a reporter plasmid (pHyGal) in RKO cells expressing individual E6 or E7 genes of either high-risk (HPV16) or low-risk (HPV6, HPV11) type viruses. Cells expressing HPV16 E6 or HPV16 E7 exhibited a significantly increased frequency of pHyGal integration in comparison to RKO control cells or cells expressing low-risk HPV E6 or E7. Thus, expression of high-risk, but not low-risk, E6 and E7 proteins increases the frequency of foreign DNA integration into the host genome. These findings suggest that at least some of the difference in oncogenic potential observed between high-risk and low-risk HPV types may be determined by the increased ability of high-risk HPVs to integrate into host DNA.

Suramin induces phosphorylation of the high-affinity nerve growth factor receptor in PC12 cells and dorsal root ganglion neurons

Suramin is a polysulfonated naphthylurea with demonstrated antineoplastic activity. Toxicity includes adrenal insufficiency and peripheral neuropathy. Although the mechanism of antitumor activity is unknown, inhibition of binding of growth factors to their receptors has been suggested. Growth factors inhibited by suramin include platelet-derived growth factor, fibroblast growth factor, transforming growth factor, epidermal growth factor, insulin-like growth factor, and nerve growth factor (NGF). In these studies, suramin was shown to be cytotoxic to PC12 cells in a dose-dependent manner. At lower doses and in surviving cells, we observed the induction of neurite outgrowth. To determine the mechanism of suramin-induced neurite outgrowth, PC12 cells were exposed to suramin and/or NGF for various time periods and treated cells were analyzed, by western blot analysis, for expression of tyrosine phosphoproteins. There was a similarity in the pattern of tyrosine-phosphorylated proteins in PC12 cells stimulated with suramin or NGF. Of particular interest was the rapid phosphorylation (by 1 min) of the high-affinity NGF (TrkA) receptor. Activation of other members of the signal-transduction cascade (Shc, p21ras, Raf-1, ERK-1) revealed similar phosphorylation levels induced by suramin and NGF. Parallel studies were performed in rat dorsal root ganglion cultures; suramin potentiated neurite outgrowth and activated the NGF receptor on these cells. This finding of specific patterns of tyrosine phosphorylation of cellular proteins in response to suramin treatment demonstrated that suramin is a partial agonist for the NGF receptor in both PC12 cells and dorsal root ganglion neurons.

Tissue- and transformation-specific phosphotyrosyl proteins in v-erbB-transformed cells

To understand the mechanism of tissue-specific and transformation-specific signaling by the v-ErbB oncoprotein, we have investigated signaling pathways downstream of this transmembrane tyrosine kinase. In this report, we describe tissue-specific patterns of phosphotyrosyl proteins in three distinct cell types transformed by the v-erbB oncogene: fibroblasts, erythroblasts, and endothelial cells. In addition, we describe transformation-specific tyrosine phosphorylation events and signal complex formation in v-erbB-transformed fibroblasts. Two patterns of phosphotyrosyl proteins have been detected in v-erbB-transformed cells. The first is a fibroblast-specific pattern which includes unique phosphotyrosyl proteins of 170 kDa (c-ErbB1), 158 kDa, and 120 kDa (the catenin-like protein p120cas). The second is an erythroblast/endothelial cell-specific pattern which includes a prominent unidentified phosphotyrosyl protein of 120 kDa. Evaluation of the phosphotyrosyl proteins p120cas and SHC in chicken embryo fibroblasts infected with transforming and nontransforming v-erbB mutants reveals transformation-specific patterns of tyrosine phosphorylation. One corollary of these phosphorylation events in v-erbB-transformed fibroblasts is the formation of a complex involving SHC, growth factor receptor-bound protein 2, and a novel 75-kDa phosphotyrosyl protein. The results of these studies suggest that the v-ErbB oncoprotein can couple to multiple signal transduction pathways, that these pathways are tissue specific, and that v-erbB-mediated transformation involves specific tyrosine phosphorylation events.

Activation of c-fos gene expression by a kinase-deficient epidermal growth factor receptor

The intrinsic tyrosine kinase activity of the epidermal growth factor receptor (EGFR) has been shown to be responsible for many of the pleiotropic intracellular effects resulting from ligand stimulation [W.S. Chen, C.S. Lazar, M. Poenie, R.Y. Tsien, G.N. Gill, and M.G. Rosenfeld, Nature (London) 328:820-823, 1987; A.M. Honegger, D. Szapary, A. Schmidt, R. Lyall, E. Van Obberghen, T.J. Dull, A. Ulrich, and J. Schlessinger, Mol. Cell. Biol. 7:4568-4571, 1987]. Recently, however, it has been shown that addition of ligand to cells expressing kinase-defective EGFR mutants can result in the phosphorylation of mitogen-activated protein kinase (R. Campos-González and J.R. Glenney, Jr., J. Biol. Chem. 267:14535-14538, 1992; E. Selva, D.L. Raden, and R.J. Davis, J. Biol. Chem. 268:2250-2254, 1993), as well as stimulation of DNA synthesis (K.J. Coker, J.V. Staros, and C.A. Guyer, Proc. Natl. Acad. Sci. USA 91:6967-6971, 1994). Moreover, mitogen-activated protein kinase has been shown to phosphorylate the transcription factor p62TCF in vitro, leading to enhanced ternary complex formation between p62TCF, p67SRF, and the c-fos serum response element (SRE) [H. Gille, A.D. Sharrocks, and P.E. Shaw, Nature (London) 358:414-417, 1992]. On the basis of these observations, we have investigated the possibility that the intrinsic tyrosine kinase activity of the EGFR may not be necessary for transcriptional activation mediated via p62TCF. Here, we demonstrate that a kinase-defective EGFR mutant can signal ligand-induced expression of c-fos protein and that a significant component of this induction appears to be mediated at the transcriptional level. Investigation of transcriptional activation mediated by the c-fos SRE shows that this response is impaired by mutations in the SRE which eliminate binding of p62(TCF). These data indicate that information inherent in the structure of the EGFR can be accessed by ligand stimulation independent of the receptor's catalytic kinase function.

Tyrosine kinase activity may be necessary but is not sufficient for c-erbB1-mediated tissue-specific tumorigenicity

Expression of mutant avian c-erbB1 genes results in tissue-specific transformation in chickens. Site-directed mutagenesis was used to generate kinase-defective mutants of several tissue-specific v-erbB transforming mutants by replacement of the ATP-binding lysine residue in the kinase domain with an arginine residue. These kinase-defective v-erbB mutants were analyzed for their in vitro and in vivo transforming potentials. Specifically, kinase-defective mutants of erythroleukemogenic, hemangioma-inducing, and sarcomagenic v-erbB genes were assessed for their oncogenic potential. In vitro transformation potential was assessed by soft-agar colony formation in primary cultures of chick embryo fibroblasts (CEF). In vivo transformation potential was determined by infection of 1-day-old line 0 chicks with concentrated recombinant retrovirus and then monitoring of birds for tumor formation. These transformation assays demonstrate that kinase activity is absolutely essential for transformation by tissue-specific transforming mutants of the avian c-erbB1 gene. Since all of the tissue-specific v-erbB mutants characterized to date exhibit tyrosine kinase activity in vitro but do not transform all tissues in which they are expressed, we conclude that v-erbB-associated tyrosine kinase activity may be necessary but is not sufficient to induce tumor formation.

Differential modulation of plasminogen activator gene expression by oncogene-encoded protein tyrosine kinases

Urokinase-type plasminogen activator (uPA) gene transcription is increased > or = 50-fold in chicken embryo fibroblasts (CEF) following transformation by the protein tyrosine kinase pp60v-src. Protein phosphorylation appears to play a critical role in uPA gene expression in these cells; protein kinase C-activating phorbol esters cooperate with pp60v-src to synergistically increase uPA mRNA, whereas cyclic AMP (cAMP)-dependent protein kinase-activating agents (e.g., 8-bromo cAMP) repress uPA mRNA levels. To explore the relationship between transforming oncogenes and uPA gene expression, uPA mRNA levels were measured in CEF infected with selected avian retroviruses. We report that v-ras and the transforming protein tyrosine kinases v-src, v-yes, and v-ros all increase cellular uPA mRNAs. However, transformation with the protein tyrosine kinase encoded by v-erbB, or the nuclear proteins encoded by v-jun, v-ski, or v-myc, did not increase uPA mRNA detectably. Ras and all of the protein tyrosine kinases analyzed, including the v-erbB product, but none of the nuclear oncoproteins sensitized cells to phorbol ester induction of uPA gene expression. Thus, increased uPA gene expression is not simply a secondary consequence of cell transformation but, rather, is regulated or comodulated by only a subset of oncogene products. Analysis of cells expressing site-directed mutants of pp60v-src showed that the induction of the uPA gene is dependent on protein tyrosine kinase catalytic activity, myristylation, and plasma membrane localization. However, these properties together are not sufficient; an additional feature in the src homology 2 domain is also required. The major sites of serine phosphorylation, serines 12 and 17, and the autophosphorylation site, tyrosine 416, are not essential for uPA gene induction. However, the reduction of uPA mRNA in pp60v-src-transformed cells by 8-bromo cAMP is dependent on tyrosine 416.

Rheumatoid pericarditis: clinical features and survival

We describe the clinical characteristics and actuarial survival of a consecutive cohort of 41 patients with rheumatoid arthritis and clinical pericarditis who were seen at the Mayo Clinic between 1970 and 1987 and followed up until death or through 1987. The survivors were followed up for a median of 5.1 years. Approximately three-fourths of our patients had acute pericarditis, the remainder having recurrent acute pericarditis, chronic pericarditis with effusion, or chronic constrictive pericarditis. Most patients had symmetrical joint swelling, morning stiffness, subcutaneous nodules, rheumatoid factor, and classic radiographic changes of rheumatoid arthritis. Common extra-articular features included fatigue, loss of weight, and fever. Dyspnea or orthopnea, typical pericardial pain, peripheral edema, tachycardia, tachypnea, a diminished mean blood pressure, a pericardial friction rub, jugular venous distension, rales, radiographic evidence of cardiomegaly and pleural effusions, and abnormal echocardiograms were the most common cardiac manifestations. An elevated erythrocyte sedimentation rate and anemia were other common laboratory findings. Our cohort demonstrated decreased survival in comparison with an age- and sex-matched North Central white population (from the upper midwestern United States), especially during the first year after diagnosis. Increasing age, the presence of other heart disease, an increasing total number of other extra-articular manifestations of rheumatoid arthritis, jugular venous distention, and a lower mean blood pressure were associated with decreased survival.

The association of stroke and coronary heart disease: a population study

In a 20-year population-based study (1960 through 1979), we estimated the cumulative probability of (1) the occurrence of stroke after a diagnosis of angina pectoris, (2) the occurrence of stroke after a diagnosis of myocardial infarction, and (3) the occurrence of myocardial infarction or sudden unexpected death after a diagnosis of cerebral infarction. In patients in whom angina had been diagnosed, no significant difference was noted between the observed and the expected probability of stroke throughout 10 years of follow-up. In patients with a diagnosis of myocardial infarction, a significant difference was noted between observed and expected probabilities of stroke at 1 month and at 2 months. This early excess in probability of stroke was especially pronounced in the subgroup of patients with transmural myocardial infarction but not evident in those with subendocardial myocardial infarction. Among patients with a diagnosis of cerebral infarction, the difference between observed and expected probabilities of myocardial infarction or sudden unexpected death was not significant until 5 years after the cerebral infarction and showed no change thereafter.

Coronary heart disease in residents of Rochester, Minnesota. VII. Incidence, 1950 through 1982

An epidemiologic study of coronary heart disease in residents of Rochester, Minnesota, has been updated through 1982. Between the time that mortality rates began to decline in the late 1960s and now, the age-adjusted incidence of all types of coronary heart disease in residents of Rochester decreased 11% in men but increased 9% in women. This difference was due mainly to changes in the incidence of myocardial infarction as the initial manifestation of coronary heart disease-in men, the rates declined by 20%, whereas the rates for women increased by 17%. The greatest changes were in the age group 50 to 69 years. From the 1965 through 1969 period to the 1979 through 1982 period, the age-adjusted incidence of sudden unexpected death as the initial manifestation of coronary heart disease decreased in both sexes, but the incidence of angina pectoris increased in both men and women. The 24-hour and 30-day case fatality rates for myocardial infarction and the incidence rates for sudden unexpected death have stabilized. Additional studies are needed to identify the reasons for the striking divergence in secular trends in coronary heart disease for men as compared with those for women.

Coronary heart disease in residents of Rochester, Minnesota. VI. Hospital and posthospital course of patients with transmural and subendocardial myocardial infarction

During the period 1960 through 1979, 1,221 residents of Rochester, Minnesota, who were 30 years of age or older had a myocardial infarction as the first manifestation of coronary heart disease. Patients who had a prior diagnosis of congestive heart failure or valvular heart disease were excluded from this study. Of the 1,221 patients, 784 had a transmural infarction, 353 had a subendocardial infarction, and 84 had infarctions that could not be classified (most of the unclassified infarctions were associated with sudden death in patients who were not hospitalized). The age- and sex-adjusted 30-day case fatality rate was 18% among those with transmural and 9% among those with subendocardial myocardial infarction. No significant difference was found in subsequent survivorship or in net survivorship free of reinfarction during the first 5 years of follow-up. Five-year net survivorship free of reinfarction, coronary artery bypass operation, and cardiac death was not significantly different between the two groups, nor was net survivorship free of five established events (the three aforementioned events plus the development of congestive heart failure or angina). When these five events were considered independently in the two infarction cohorts, however, development of congestive heart failure was more common among patients with transmural infarction (P less than 0.01), whereas the development of angina was more common among patients with subendocardial myocardial infarction (P less than or equal to 0.06).

Constrictive pericarditis: assessment of current diagnostic procedures

Constrictive pericarditis frequently poses a diagnostic challenge because of its varied manifestations. Accurate diagnosis is essential, however, because surgical decortication may yield excellent clinical results. Although new diagnostic procedures have helped the clinician to diagnose constrictive pericarditis, the initial clinical suspicion of this diagnosis must be high for appropriate interpretation of these tests. Echocardiography is useful, primarily for distinguishing various other cardiac abnormalities that may simulate constrictive pericarditis. Computed tomography is a valuable procedure for assessment of pericardial thickening. In addition, evaluation of early diastolic filling by computerized digitization in conjunction with echocardiography, angiography, and invasive hemodynamics shows promise as a diagnostic tool. Even with these new diagnostic aids, distinguishing constrictive pericarditis from restrictive cardiomyopathy may be difficult and, in some cases, may necessitate an exploratory operative procedure.

Coronary heart disease in residents of Rochester, Minnesota. V. Prognosis of patients with coronary heart disease based on initial manifestation

During the period 1960 through 1979, 1,014 residents of Rochester, Minnesota, had a diagnosis of classic angina pectoris as the first manifestation of coronary heart disease, and 1,013 had a myocardial infarction as the initial manifestation. In the angina cohort, about 50% were men, and of them, 20% were 70 years old or older. The female patients were an average of 6 years older than the men, and 43% were 70 years old or older. In this cohort, the 5-year survival rate increased from 77% in the 1960s to 87% in the 1970s (P less than 0.01). The 5-year net survivorship free of a myocardial infarction increased from 76% to 85% during that same time (P less than 0.01). In the myocardial infarction cohort, the 5-year death rate among the 30-day survivors of myocardial infarction was the same during both decades of the study. The age-adjusted reinfarction rate per 100 person-years at risk during teh first 5 years of follow-up decreased very slightly among men and increased among women; thus, it remained essentially unchanged overall. Although the case fatality rate in the myocardial infarction cohort declined sharply from the 1960s to the 1970s, the long-term prognosis of the 30-day survivors of a myocardial infarction did not improve.

Early and late results of pericardiectomy for constrictive pericarditis

Records of 231 patients (171 males, 60 females; aged 10 months to 83 years [median 45 years]) who underwent operation for constrictive pericarditis at the Mayo Clinic from 1936 through 1982 were reviewed. All had had hemodynamically significant pericardial constriction preoperatively, and pericardial disease was confirmed at operation. Preoperatively, 69% were in New York Heart Association Class III or IV and 81% had peripheral edema or ascites. Pericardiectomy was performed through a left anterolateral thoracotomy (34%), a median sternotomy (27%), a U incision (Harrington) (21%), or a bilateral anterior thoracotomy (18%). Postoperatively, 28% of patients had evidence of low cardiac output; 70% of the 32 deaths within 30 days of operation were due to low cardiac output. Operative risk was significantly (p less than 0.001) related to preoperative disability (1% for Class I or II; 10% for class III; 46% for Class IV). Median postoperative follow-up was 9 years (longest was 43 years). Probability of survival for patients dismissed alive from the hospital was 84% at 5 years, 71% at 15 years, and 52% at 30 years. Long-term survival (excluding operative mortality) was not significantly influenced by the disability class preoperatively, the operative approach, or the development of low cardiac output in the immediate postoperative period. At the end of the follow-up interval, there were 141 patients in whom functional capacity could be assessed; 140 were in Class I or II. We conclude that a poor hemodynamic result after complete pericardiectomy relates to the preoperative degree of constriction and resultant cardiomyopathy. We recommend early pericardiectomy when pericardial constriction is diagnosed, and we continue to use a left anterolateral thoracotomy as the preferred approach for most patients.

Arterial-esophageal fistulae developing in patients with anomalies of the aortic arch system

Two cases are presented in which anomalies of the aortic arch system were associated with development of an arterial-esophageal fistula. The fistula resulted in massive upper gastrointestinal hemorrhage and death. In each malformation, part of the anomalous aortic arch system lay against the esophagus and thereby provided the anatomic substrate for an arterial-esophageal fistula. In both cases, nonmassive ("sentinel") hemorrhage occurred prior to the massive fatal hemorrhage. Recognition of the significance of the "sentinel" hemorrhage may allow surgical correction of the problem avoiding uncontrolled massive hemorrhage.

Coronary heart disease in residents of Rochester, Minnesota. IV. Prognostic value of the resting electrocardiogram at the time of initial diagnosis of angina pectoris

The data in this study were based on the 1,154 Rochester residents in whom a resting electrocardiogram had been obtained at the time of diagnosis of angina pectoris as the initial manifestation of coronary heart disease during the 26-year period 1950 through 1975. The finding of a normal electrocardiogram at the time of the initial diagnosis of angina pectoris was associated with a good prognosis. Survival at 5 years was equal to that expected, for the given age and sex distribution, under a cohort life table for the Minnesota white population. In contrast, in those patients who had an abnormal electrocardiogram at the time of diagnosis, the observed survival rate was 86% of that expected at 5 years.

Two decades of cardiac pacing at the Mayo Clinic (1961 through 1981)

Pacemaker procedures performed at the Mayo Clinic for the years 1961, 1971, and 1981 were reviewed to examine the changes that have occurred in a large pacemaker practice during the 2 decades since the advent of pacemaker therapy. Major changes in trends and practice have occurred; in addition to numerical growth, the indications for permanent pacing and the technologic alternatives available have expanded considerably. The increasing choices available today (in all areas of pacemaker practice) provide a challenging stimulus to physicians as they seek the best clinical options in patient care.

The dichotomy of myocardial and cerebral infarction

The Mayo Clinic medical record linkage and indexing system was used to examine changes in incidence and case fatality of myocardial infarction (MI), sudden unexpected death (SUD), and cerebral infarction (CI). The average annual age and sex adjusted incidence rates for MI (including SUD) and CI declined by 14% and 55%, respectively, between 1950-54 and 1975-79. The decline in the incidence of MI was due to a reduction in sudden unexpected death (SUD), greatest in younger persons. 30-day case fatality after MI declined from 50% to 35% during this period.

Coronary heart disease in residents of Rochester, Minnesota, 1950-1975. III. Effect of hypertension and its treatment on survival of patients with coronary artery disease

The data in this blood pressure study were obtained from 1,069 patients who had their first manifestation of coronary artery disease during the 16-year period 1960 through 1975. Case fatality rates (death within 30 days) were least in the normotensive and treated hypertensive patients with myocardial infarction and greatest in the untreated hypertensive patients. Women were less likely than men to acquire coronary artery disease, but a higher proportion of women with coronary artery disease had hypertension. Patients with definite hypertension were older than those with borderline hypertension, and patients with borderline hypertension were older than normotensive patients with coronary artery disease. The data demonstrate that hypertension is a prognostic factor of serious significance in patients who have symptomatic coronary artery disease, and the prognostic significance of borderline hypertension is almost as serious as that of definite hypertension in these patients. Treatment improved survival in patients with definite hypertension, and adequate treatment improved survival to a greater degree than did inadequate treatment.

Coronary heart disease in residents of Rochester, Minnesota. II. Mortality, incidence, and survivorship, 1950-1975

For the city of Rochester, Minnesota, the coronary heart disease mortality rate showed approximately the same percentage decline as that for the United States during the period 1968-1978. The incidence rates of coronary heart disease (angina pectoris, myocardial infarction, and sudden unexpected death) for the period 1950-1975 are based on a total of 3,080 cases. The incidence showed a decrease approximately 10 years earlier than the decline in mortality and little change since that time. The age-adjusted case fatality rate for the incidence cases of myocardial infarction decreased from 18.7% in 1965-69 to 9.0% in 1970-75. The death rate during the 5 years following the diagnosis of angina also decreased by almost 50%, and the myocardial infarction patients dismissed from the hospital showed little change in subsequent survivorship.

Coronary heart disease in residents of Rochester, Minnesota, 1950-1975. I. Background and study design

The unique medical data resource for the population of Rochester, Minnesota, is centered on the records of the Mayo Clinic and the Olmsted Medical and Surgical Group, which for several decades have provided nearly all medical care in this community. This resource has been utilized in a study of the incidence rates and secular trend in coronary heart disease for the period 1950-1975 among residents of Rochester. A total of 3,080 patients fulfilled the clinical and other criteria for inclusion in this study. The patients, classified by initial manifestation of coronary heart disease, consisted of 1,321 with myocardial infarction, 1,215 with angina pectoris, and 544 with sudden unexpected death. In this paper the background, clinical definitions, and study design are presented.

Survival predictors in coronary artery disease. Medical and surgical comparisons

Linear discriminant function analysis was used to test the independent prognostic value of nine variables in patients with coronary artery diseaase. For 68 medically treated patients who met the criteria for inclusion in the discriminant function analysis, the most reliable predictor of 2-year survival status was the left ventricular ejection fraction. The prognostic value of the ejection fraction was not improved by the addition of the number of vessels diseased. Comparisons of the survival of 130 medical and 284 surgical patients were made using subsets based on the ejection fraction. When the ejection fraction was greater than or equal to 50%, the probability of 4-year survival was high for both medical (91%) and surgical (96%) groups. When the ejection fraction was less than 25%, the probability of 2-year survival was low in both groups. However, for patients with ejection fraction 25 through 49%, the surgical patients had a better chance (P less than 0.05) for a 3-year survival (89%) than did medical patients (68%). This study emphasizes the prognostic significance of the left ventricular ejection fraction, which should be considered in any comparison of survival in medically and surgically treated patients.

Videometric analysis of regional left ventricular function before and after aortocoronary artery bypass surgery: correlation of peak rate of myocardial wall thickening with late postoperative graft flows

The peak rate of systolic wall thickening (pdTw/dt) in regions of the left ventricle was determined by biplane roentgen videometry in 60 patients before and a median of 14 mo after aorto-coronary bypass graft surgery. The left ventricular ejection fraction, stroke volume, and end-diastolic volume and pressure did not change significantly after surgery in the presence of patent or occluded grafts (P greater than 0.05). Statistically significant increases occurred in the peak rate of systolic wall thickening regions supplied by patent bypass grafts, and significant decreases occurred in regions with occluded grafts (P less than 0.01). Of 42 preoperatively hypokinetic regions (pdTw/dt greater than 0 less than 5.0 cm/s) supplied by a patent graft, 30 improved by an average of 2.6 cm/s after operation; 18 returned to normal. Failure of 24 hypokinetic regions to improve to normal was associated with myocardial infarction in 11 or with late postoperative graft blood flows of less than 60 ml/min measured by videodensitometry, in 10. All seven preoperatively akinetic (pdTw/dt=0) or dyskinetic (pdTw/dt less than 0) regions did not improve after the operation despite the fact that, in five of the seven, coronary bypass flows were over 60 ml/min. All eight preoperatively hypokinetic regions supplied by coronary artery graft flows of less than or equal 40 ml/min failed to improve to normal after operation. All nine preoperatively hypokinetic regions supplied by coronary artery graft flows of over 60 ml/min improved to normal after surgery. Late postoperative coronary artery bypass graft flows, the functional status of the myocardium, the status and distribution of the native coronary circulation, and decreased regional function elsewhere in the ventricle must all be considered when regional left ventricular function is interpreted.

Diabetes mellitus: incidence, prevalence, survivorship, and causes of death in Rochester, Minnesota, 1945-1970

The incidence and prevalence of diabetes mellitus in residents of Rochester, Minnesota, for 25 years (1945 to 1970) were determined from available medical records. The over-all incidence rate for diabetes is 133 new cases per 100,000 population per year (age-adjusted to 1970 U.S. white population). The rate increased with age for both men and women and was higher among men over 30 years of age. The average annual incidence rates per five-year period for juvenile-onset diabetes mellitus were low and variable and showed little change. Polyuria, polydipsia, glycosuria, lean habitus, loss of weight, and high levels of fasting hyperglycemia at initial diagnosis occurred more frequently in younger than in older patients. The peak incidence in 1960 through 1964 and the decrease in the following five years may be a reflection of the introduction of the AutoAnalyzer method for blood glucose in 1958. The average annual incidence rates for 1955 through 1959 and 1965 through 1969 were essentially the same. The over-all prevalence for diabetes mellitus is 1.6 per cent, with a higher rate among men than among women over 40 years of age; among school children the rate is 0.1 per cent. Survivorship in the diabetic population is lower than that in the general population. The leading cause of death was coronary heart disease, the death rate from it being higher than for the general population.

Isolated replacement of the mitral valve with the Starr-Edwards prosthesis

Isolated mitral valve replacement with the Starr-Edwards prosthesis has been performed on 657 patients at the Mayo Clinic during the 11 year period ending January, 1972. The most recent subset of that series comprised patients who received the Model 6120 prosthesis. In this group, the operative mortality rate was 9 per cent and the actuarial late death rate at 5 years was 20 per cent. This survival rate is a significant improvement over the natural history of severe mitral valve disease. Factors associated with operative deaths are large left artrial size, advanced functional class, and previous heart surgery. Variables associated with higher incidence of late deaths are large left atrial size, patient age at operation, and multivalve disease. Risk of thromboembolism is increased with large left atrial size, presence of left atrial thrombus, and inadequate anticoagulant therapy.

Arteriographic patterns early in the onset of the coronary syndromes

Coronary arteriography in 300 patients within one year of onset of symptoms of coronary arterial disease revealed already severe anatomical coronary disease in three patient groups: those with angina pectoris alone (164 patients), with subendocardial myocardial infarction (63 patients), and with transmural myocardial infarction (73 patients). The number of vessels diseased (larger than or equal to 50% obstruction), distribution of obstruction, and degree of stenosis were similar in the three groups. However, total occlusion of at least one artery was much more common in transmural myocardial infarction and in subendocardial myocardial infarction with elevation of enzyme levels. We suggest that such occlusions occurred at the time of the infarction. Similarities in coronary anatomy between patient subgroups with angina (on exercise or at rest and nocturnal) indicate that factors other than coronary anatomy intervene in precipitating the different types of angina. Vessel disease was not related to smoking, hyperlipidaemia, or hypertension but coronary disease was manifest earlier in life in smokers or those with hyperlipidaemia.

Isolated replacement of the aortic valve with the Starr-Edwards prosthesis. A 9 year review

A 9 year review of patients who underwent replacement of the aortic valve with the Starr-Edwards prosthesis indicates that the operative mortality rate for aortic valve replacement continues to decline. Thromboembolic complications have been markedly lessened in newer model valves. Surgical therapy is no longer seriously questioned as the appropriate management for symptomatic aortic valvular disease. The large majority of patients who survive surgery can expect to be rehabilitated to a highly functional existence, with longevity not unlike that of the general population. The Starr-Edwards prosthesis is a very satisfactory prosthesis for replacement of the aortic valve.

Aorta-coronary artery saphenous vein bypass surgery: clinical and angiographic results

In a series of 500 consecutive patients undergoing aorta-coronary artery saphenous vein bypass surgery, operative mortality was 2.5% (1% with one-vessel disease, 2% with two-vessel disease, and 3% with three-vessel disease). Transmural myocardial infarction occurred within 30 days after operation in 67 cases (13%) and caused 10 of the 16 deaths in that period. Among 484 patients followed 1 to 58 months (median, 26 months), there have been 20 deaths. Of the 464 survivors, 65% had complete relief of angina, 24% were improved, and 11% were unimproved. In 162 patients who underwent postoperative graft angiography between 1 and 42 months after surgery, a strong positive relationship existed between clinical response and completeness of myocardial revascularization as defined by the presence of a patent graft to all major coronary arteries with greater than 50% stenosis. A similar relationship was found between postoperative multistage treadmill exercise response and completeness of myocardial revascularization. Thus, 82% of patients completely revascularized were asymptomatic at the time of postoperative graft visualization, and 91% had a negative treadmill exercise response.

Serum enzyme data in diagnosis of myocardial infarction during or early after aorta-coronary saphenous vein bypass graft operations

In 397 cases, serum glutamic oxaloacetic transaminase (GOT) and creatine phosphokinase (CPK) values were determined on the first, second, and third days after aorta-coronary artery saphenous vein bypass graft operations. Electrocardiographic (ECG) or vectorcardiographic (VCG) evidence of postoperative transmural infarction was found in 48 cases. Multivariate analysis indicated that GOT and CPK concentrations on day 1 had substantial discriminatory value regarding infarction. Discrimination by GOT values was not significantly improved by addition of CPK. Of the 61 cases positive by GOT values measured 1 day postoperatively (greater than 100 U. per liter; normal smaller than 24), 32 (52 percent) were negative by ECG or VCG; of the 336 cases negative by GOT, 19 (6 percent) were positive by ECG or VCG. GOT and CPK values increased with the number of vessels grafted and with the use of ventricular rather than atrial vents. Total serum enzyme values lack specificty in diagnosis of transmural infarction after the saphenous vein bypass operation.

Aorta-coronary artery saphenous vein bypass grafts. Isolated and combined with other procedures

The results in 578 patients who underwent a saphenous vein bypass graft operation (isolated SVBG) or a SVBG combined with other procedures (combined SVBG) from 1969 through 1972 were analyzed. The operative mortality rate was low (3 percent) for isolated SVBG but increased considerably for combined SVBG. The late mortality rate was also low (4 percent) for isolated SVBG and also increased markedly for combined SVBG. The operative mortality rate did not change in the group undergoing left ventricular aneurysmectomy or mitral valve surgery for postinfarction mitral insufficiency, whether or not SVBG was used; however, late results were better in both groups when SVBG was performed. Among all groups, patients with postinfarction mitral insufficiency or rheumatic mitral incompetence associated with coronary artery disease had the poorest outcome. Despite the operative and late deaths, patients undergoing SVBG with aortic valve replacement showed excellent results in the group of survivors.

Long-term follow-up of isolated replacement of the aortic or mitral valve with the Starr-Edwards prosthesis

Review of 1,684 cases of isolated aortic or mitral valve replacement with a Starr-Edwards prosthesis demonstrated that the procedure provides improved life expectancy over that found in the natural history of valvular heart disease. Further improvement in results depends on continued reduction in operative and late mortality and in the incidence of thromboembolism. Advanced preoperative functional class, atrial or ventricular enlargement, a history of prior heart surgery, advanced age at operation and untreated valvular disease were among the factors related to increased early or late mortality. The data suggest that adequate anticoagulation, earlier performance of valve replacement and more complete repair of valvular dysfunction may increase survival rates.

Mitral valve replacement with the Smeloff-Cutter prosthesis. Experience with 154 patients and comparison with results of replacement with a Starr-Edwards prosthesis

Mitral valve replacement with the Smeloff-Cutter (S-C) prothesis was performed in 154 patients between September, 1965, and January, 1970. In 84, only the mitral valve was replaced; in the remainder, other valves were reconstructed or replaced. The hospital and late mortality rates for isolated replacement were 6 and 25 per cent, respectively. Comparable figures for the Starr-Edwards (S-E) (Models 6000 and 6120) prosthesis during this period were 11 and 23 per cent. Similar rates of thromboembolism were associated with the use of either prosthesis in surviving patients (27 per cent for the S-C valve and 30 per cent for the S-E valve). In spite of the acceptable hospital mortality rate for the S-C valve, it is not now considered suitable for clinical use because of the high late mortality rate and the high risk of thromboembolism that accompany its use.