Expression and polymorphism (rs4880) of mitochondrial superoxide dismutase (SOD2) and asparaginase induced hepatotoxicity in adult patients with acute lymphoblastic leukemia.

Asparaginase, which depletes asparagine and glutamine, activates amino-acid stress response. Oxidative stress mediated by excessive reactive oxygen species (ROS) causes enhanced mitochondrial permeabilization and subsequent cell apoptosis and is considered as a plausible mechanism for drug-induced hepatotoxicity, a common toxicity of asparaginase in adults with acute lymphoblastic leukemia (ALL). Studies investigating the pharmacogenetics of asparaginase in ALL are limited and focused on asparaginase-induced allergic reaction common in pediatric patients. Here, we sought to determine a potential association between the variant rs4880 in SOD2 gene, a key mitochondrial enzyme that protects cells against ROS, and hepatotoxicity during asparaginase-based therapy in 224 patients enrolled on CALGB-10102, a treatment trial for adults with ALL. We report that the CC genotype of rs4880 is associated with increased hepatotoxicity following asparaginase-based treatment. Thus, rs4880 likely contributes to asparaginase-induced hepatotoxicity, and functional studies investigating this single-nucleotide polymorphism (SNP) are needed to develop therapeutic approaches that mitigate this toxicity.

Investigating a tuberculosis cluster among Filipino health care workers in a low-incidence country.

SETTING: Nearly 8% of adult tuberculosis (TB) cases in England, Wales and Northern Ireland (EW&NI) occur among health care workers (HCWs), the majority of whom are from high TB incidence countries. OBJECTIVES: To determine if a TB cluster containing multiple HCWs was due to nosocomial transmission. METHODS: A cluster of TB cases notified in EW&NI from 2009 to 2014, with indistinguishable 24-locus mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) profiles, was identified through routine national cluster review. Cases were investigated to identify epidemiological links, and occupational health (OH) information was collected for HCW cases. To further discriminate strains, typing of eight additional loci was conducted. RESULTS: Of the 53 cases identified, 22 were HCWs. The majority (n = 43), including 21 HCWs, were born in the Philippines. Additional typing split the cluster into three subclusters and seven unique strains. No epidemiological links were identified beyond one household and a common residential area. HCWs in this cluster received no or inadequate OH assessment. CONCLUSIONS: The MIRU-VNTR profile of this cluster probably reflects common endemic strains circulating in the Philippines, with reactivation occurring in the UK. Furthermore, 32-locus typing showed that 24-locus MIRU-VNTR failed to distinguish strain diversity. The lack of OH assessment indicates that latent tuberculous infection could have been identified and treated, thereby preventing active cases from occurring.

K-ras mutations in putative preneoplastic lesions in human colon.

BACKGROUND: A mutation in c-K-ras (KRAS2) has long been implicated as one of the important early events in the development of a large proportion of human colon cancers. Aberrant crypt foci, putative preneoplastic lesions identified microscopically in wholemounts of colons, have been shown to occur with high frequency in the colons of animals treated with colon carcinogens and in the grossly normal mucosas of patients with colon cancer. PURPOSE: In this study, we asked whether the mutational activation of K-ras occurs in the aberrant crypt foci of human colon. METHODS: Grossly normal colonic mucosas were obtained from seven patients during surgery and were provided to us by the Western Division of the Cooperative Human Tissue Network located at Case Western Reserve University. A total of 42 samples, consisting of aberrant crypt foci and similarly sized normal crypt areas, were microdissected from the grossly normal colonic mucosas. The DNA region containing codon 12 of K-ras was amplified by polymerase chain reaction and analyzed for mutations by dot-blot hybridization with specific oligonucleotide probes complementary to normal or mutant sequences. RESULTS: Mutations in codon 12 of K-ras were found in 11 (73%) of 15 aberrant crypt foci but not in any of 27 morphologically normal crypt areas from the same patients. CONCLUSIONS: The observed high frequency of K-ras mutations in these microscopically identifiable lesions makes mutation in K-ras the earliest identified gene-mutational event in human colon tumorigenesis, establishes that it often occurs prior to the development of polyps, and is consistent with the hypothesis that aberrant crypt foci are the earliest identified precursors of human colon cancer. IMPLICATIONS: Further analysis of aberrant crypt foci may identify yet unknown early genetic events that precede human colon cancer.

Comprehensive mutational analysis of primary and relapse acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by differentiation block at the promyelocyte stage. Besides the presence of chromosomal rearrangement t(15;17), leading to the formation of PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha) fusion, other genetic alterations have also been implicated in APL. Here, we performed comprehensive mutational analysis of primary and relapse APL to identify somatic alterations, which cooperate with PML-RARA in the pathogenesis of APL. We explored the mutational landscape using whole-exome (n=12) and subsequent targeted sequencing of 398 genes in 153 primary and 69 relapse APL. Both primary and relapse APL harbored an average of eight non-silent somatic mutations per exome. We observed recurrent alterations of FLT3, WT1, NRAS and KRAS in the newly diagnosed APL, whereas mutations in other genes commonly mutated in myeloid leukemia were rarely detected. The molecular signature of APL relapse was characterized by emergence of frequent mutations in PML and RARA genes. Our sequencing data also demonstrates incidence of loss-of-function mutations in previously unidentified genes, ARID1B and ARID1A, both of which encode for key components of the SWI/SNF complex. We show that knockdown of ARID1B in APL cell line, NB4, results in large-scale activation of gene expression and reduced in vitro differentiation potential.

A novel nuclear protein, 5qNCA (LOC51780) is a candidate for the myeloid leukemia tumor suppressor gene on chromosome 5 band q31.

Interstitial deletion or loss of chromosome 5, del(5q) or -5, is a frequent finding in myeloid leukemias and myelodysplasias, suggesting the presence of a tumor suppressor gene within the deleted region. In our search for this gene, we identified a candidate, 5qNCA (LOC51780), which lies within a consistently-deleted segment of 5q31. 5qNCA expresses a 7.2-kb transcript with a 5286-bp open reading frame which is present at high levels in heart, skeletal muscle, kidney, placenta, and liver as well as CD34+ cells and AML cell lines. 5qNCA encodes a 191-kD nuclear protein which contains a highly-conserved C-terminus containing a zinc finger with the unique spacing Cys-X2-Cys-X7-His-X2-Cys-X2-Cys-X4-Cys-X2-Cys and a jmjC domain, which is often found in proteins that regulate chromatin remodeling. Expression of 5qNCA in a del(5q) cell line results in suppression of clonogenic growth. Preliminary sequence results in AML and MDS samples and cell lines has revealed a possible mutation in the KG-1 cell line resulting in a THR to ALA substitution that has not been found in over 100 normal alleles to date. We propose 5qNCA is a good candidate for the del(5q) tumor suppressor gene based on its predicted function and growth suppressive activities, and suggest that further mutational and functional study of this interesting gene is warranted.

Germ cell proliferation and apoptosis in the developing human ovary.

CONTEXT: The regulation of germ cell proliferation and loss during human ovarian development is poorly understood. This is of particular interest at the time leading up to the formation of primordial follicles, at 18 wk gestation onward. OBJECTIVE: The objective of the study was to identify and quantify germ cell proliferation and apoptosis and expression of caspases in the human fetal ovary. DESIGN: This study was a laboratory investigation. SETTING: The study was conducted at a research institute. METHODS: Cell proliferation and apoptosis were detected using immunohistochemical localization of phosphorylated histone H3 and cleaved caspase-3, respectively. Caspases were also detected by immunoblotting. RESULTS: The overall proportion of germ cells in mitosis remained constant between 14 and 19 wk but showed increasing clustering. Caspase-2, -3, -7, -8, and -9 were detected by immunoblotting. There was a significant increase in germ cell apoptosis. A specimen of 20 wk gestation showed similar phosphorylated histone H3 but markedly lower cleaved caspase-3 expression than earlier gestations. Cleaved caspase-3 was not expressed in oocytes that had formed primordial follicles. CONCLUSIONS: These results indicate that as primordial follicle formation is initiated and progresses, there is an increase in both mitotic activity and apoptosis of those germ cells that have not reached the apparently protective environment of the primordial follicle.

Developmental changes in expression of myeloid cell leukemia-1 in human germ cells during oogenesis and early folliculogenesis.

The regulation of germ cell number in the developing ovary is central to female reproduction. Members of the Bcl-2 family of proapoptotic and antiapoptotic proteins have been implicated in this process in rodents. We investigated the expression of Mcl-1, Bcl-2, Bax, and BAD at 13-21 gestational wk in the human fetal ovary and of Mcl-1 in the adult ovary. mRNA expression of Mcl-1 and its short form Mcl-1s, Bcl-2, Bax, and BAD was demonstrated in fetal ovary by RT-PCR. Hybridization array analysis suggested a selective increase in Mcl-1 expression between 14 and 18 wk gestation, which was confirmed by quantitative PCR. There was a corresponding change in the expression of Mcl-1 protein, detected by immunohistochemistry, from germ cells at the periphery of the ovary at 14-16 wk to the largest germ cells, including oocytes within newly formed primordial follicles, at 21 wk. Mcl-1 was also expressed by oocytes of primordial and preantral follicles in the adult. Bax and BAD immunostaining was detected in both somatic and germ cells in the fetal ovary, whereas Bcl-2 was restricted to somatic cells: no changes in expression were observed. Apoptotic cells, detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, were observed in all fetal ovaries but were infrequent. These results confirm that Bcl-2 family members are differentially expressed in several cell types within the developing human ovary. Increased mRNA expression and the changing distribution of Mcl-1 in germ cells as they develop into primordial follicles as well as persistence in the growing oocyte in the adult may indicate an important role for this survival/antiapoptotic factor throughout germ cell development and maturation.

N-ras mutation: an independent prognostic factor for aggressiveness of papillary thyroid carcinoma.

BACKGROUND: The clinical importance of point mutations of ras oncogene in differentiated thyroid cancers has not been fully clarified. The purpose of this study is to determine the prognostic importance of ras mutation in papillary thyroid carcinoma. METHODS: Tumors of 91 patients with papillary carcinoma were studied; mean follow-up was 14.1 years (range, 1 to 40 years). Patients were grouped as follows: class I, intrathyroidal disease, n = 21; class II, cervical node metastases, n = 22; class III, extrathyroidal disease, n = 19; and class IV, distant metastases, n = 29. DNA was analyzed with polymerase chain reaction, oligonucleotide hybridization, and DNA sequence analysis techniques. RESULTS: Thirteen (14.3%) of 91 tumors showed an N-ras point mutation: 4.8% (1 of 21) patients in class I; 4.5% (1 of 22) patients in class II; 15.8% (3 of 19) patients in class III; and 27.8% (8 of 29) patients in class IV. Each mutation changed codon 61 from glutamine to arginine. Patients with distant metastases (8 of 29) had a significantly higher incidence of ras mutations than others (5 of 62, p = 0.01). Patients in classes III and IV also had a higher incidence of mutations (11 of 48) than patients in classes I and II (2 of 43, p = 0.01). The incidence of ras mutations was significantly higher in patients who died of papillary cancer (5 of 15, 33.3%) than in patients who are still alive (8 of 76, 10.5%) (p = 0.02). Kaplan-Meier survival curves also showed a greater mortality from tumor (p < 0.05) and a higher recurrence rate (p < 0.01) in ras-positive tumors than in the ras-negative group. Finally, in studies by multivariate analyses, positive ras mutation and age were shown to be two independent prognostic factors for prediction of death from papillary cancer and recurrence of cancer. CONCLUSIONS: Mutation of N-ras gene at codon 61 is an independent prognostic factor for aggressiveness of papillary thyroid carcinomas.

N-ras 61 oncogene mutations in Hürthle cell tumors.

Mutations of ras oncogenes are believed to play an important role in the initiation or progression of human tumors. In thyroid tumors the incidence of ras activation by specific point mutations has been reported to range from 33% in follicular adenomas up to 60% in anaplastic carcinomas. Because of our long-standing interest in Hürthle cell tumors, we began a study of 70 such cases to determine the incidence of ras mutations and their clinical correlates. Analysis of N-ras sequences at codon position 61, with the polymerase chain reaction method and oligonucleotide probe hybridization, showed point mutations of the normal codon CAA* in eight tumor samples. One was a mutation from CAA to AAA, one from CAA to CTA,* and six from CAA to CGA. These mutations would result in amino acid substitutions of lysine, leucine, or arginine for the normal glutamine at position 61 in the N-ras protein. Identical ras mutations in two tumors and some of their surrounding thyroid tissue may indicate that activating ras point mutations are an early event in carcinogenesis. The incidence of mutations was 1 of 24 (4%) of the histologically benign tumors, 5 of 34 (15%) of the intermediate tumors (with vascular or capsular permeation), and 2 of 12 (17%) in the malignant group. Four of these eight patients died of metastatic thyroid disease and four are alive without evidence of recurrence.

Comparison of mutations of ras oncogene in human pancreatic exocrine and endocrine tumors.

BACKGROUND: Ras oncogene mutations have been found in many human cancers; however, pancreatic endocrine tumors have rarely been studied. The purpose of this study was to analyze ras mutations in pancreatic endocrine tumors and to compare these results with the incidence of ras mutations in pancreatic exocrine cancers studied in our laboratory. METHODS: Ras oncogene mutations were studied in 33 foregut endocrine tumors (pancreatic 31, duodenal submucosa 2). Eleven were insulinomas, 12 gastrinomas, 2 glucagonomas, and 11 others were nonfunctioning islet cell carcinomas. Thirteen were benign and 20 were malignant. These were compared with 65 pancreatic exocrine cancers. Tumors were microdissected from paraffin-embedded sections. DNA was extracted and amplified by polymerase chain reaction. Mutations were detected by a oligonucleotide hybridization method with sequence-specific phosphorus 32-radiolabeled probes. RESULTS: No ras mutations were identified among the 33 pancreatic endocrine tumors. In contrast, 51 of 65 (78.5%) pancreatic exocrine cancers exhibited a ras mutation. Fifty were K-ras mutations and one unusual tumor exhibited a N-61 ras mutation. CONCLUSIONS: Ras oncogene mutations do not play a role in the tumorigenesis of pancreatic endocrine tumors.

Difficulties of parathyroidectomy after previous thyroidectomy.

Although the risks of reoperative thyroidectomy and parathyroidectomy have been well studied, the problems associated with parathyroidectomy after prior thyroidectomy have not been emphasized. Among a group of 282 patients who were treated for primary hyperparathyroidism in recent years at the University of Chicago Medical Center, 14 (4.8%) had undergone one or more previous thyroidectomies, and 6 others (2.1%) had undergone thyroid ablation with radioactive iodine as therapy for Graves' disease. Numerous difficulties were encountered during surgery in the postthyroidectomy group of patients as a result of scarring and fibrosis, prior recurrent laryngeal nerve injuries in 13%, the inability to known with certainty how many viable, normal parathyroid glands remained after previous operations, and the need for additional thyroid resection, mostly for associated malignant lesions. Preoperative vocal cord assessment, evaluation of prior operative and pathology reports, and localization studies with thallium-technetium scanning and ultrasonographic techniques were especially helpful. A "lateral approach" was used frequently during surgery. Each of these 14 patients was cured of the hyperparathyroidism. The postthyroid ablation group presented fewer intraoperative challenges, although in some patients the thyroid gland was virtually absent, which obscured the normal landmarks of the surgical field. Five of these six patients were cured of hyperparathyroidism. Parathyroidectomy after thyroidectomy presents many operative challenges to the surgeon and should be approached with the same care and concern that one reserves for a reoperative parathyroid operation.

Continuing evolution in the operative management of primary hyperparathyroidism.

During the past several decades the operation for primary hyperparathyroidism at The University of Chicago, Ill, has changed from subtotal parathyroidectomy for all patients to removal of an adenoma with performance of biopsies of all other glands to bilateral neck exploration, resection of the adenoma, and performance of fewer biopsies of normal glands. During the 1980s, 308 operations were performed; 288 patients underwent first operations. Two hundred forty-five (85.1%) of these patients had an adenoma and forty-three (14.9%) had hyperplasia (multiglandular disease); none had a carcinoma. Resolution of hypercalcemia was achieved in 281 patients (97.5%); seven patients experienced failed explorations. The early cure was the same whether or not preoperative localization studies were performed. Nineteen patients underwent 20 reoperative parathyroidectomies during this period. Preoperative localization studies, done in 16 (80%) of 20 cases, were very helpful. Ninety percent of patients with abnormal parathyroid glands in their neck or mediastinum were cured with their initial reoperation.

DNA integrity in human spermatozoa: relationships with semen quality.

The literature contains conflicting evidence regarding the existence of DNA damage in spermatozoa from infertile male patients. To examine this phenomenon, we have studied ejaculated spermatozoa from normozoospermic semen donors and from a group of the unselected male partners of couples attending an infertility clinic for initial investigation. Classical semen analysis according to World Health Organization (WHO) guidelines was undertaken with computer-assisted sperm analysis (CASA). Spermatozoa were prepared by sequential washing and centrifugation and were analyzed for DNA fragmentation using three assays: 1) a single-cell gel electrophoresis (comet) assay, 2) in situ nick translation with prior chemical decondensation (ISNT-decondensed), and 3) in situ nick translation without prior chemical decondensation (ISNT-condensed). In addition, reactive oxygen species (ROS) generation by spermatozoa was measured, and seminal plasma was analyzed for its total reactive antioxidant potential (TRAP). When the donor and patient groups were compared, the latter had lower levels of semen quality and higher levels of DNA damage, which was particularly apparent using the comet assay. Highly significant negative correlations were observed between DNA fragmentation, detected by all three assays, and semen quality, particularly sperm concentration. In addition, multiple regression analysis indicated that other attributes of semen quality, such as sperm movement and ROS generation, were also related to DNA damage. We conclude that a significant proportion of infertile men have elevated levels of DNA damage in their ejaculated spermatozoa.

Increased incidence of thyroid cancer in patients with primary hyperparathyroidism: a continuing dilemma.

A number of previous studies have reported a greater incidence of thyroid disease in patients with primary hyperparathyroidism (HPT) than in normal patients. However, few of these studies utilized controls, and most have dealt only with gross thyroid nodules and not with total histologic abnormalities. In order to clarify this problem, thyroid pathology was determined in each of 100 consecutive patients operated upon for HPT. Thyroid nodules were excised, but in addition, a random biopsy of the thyroid was performed in all cases. Patients in this group were matched by age, race, and sex with non-HPT autopsy controls. Histologic slides were reviewed by a single pathologist blinded to the patient's group. Data for the matched pairs were analyzed by the Sign test. There was no significant difference in the prevalence of colloid nodular disease between patients with HPT (45) and the autopsy control group (43, P = 0.2). There was also no significant difference in the prevalence of lymphocytic thyroiditis between HPT patients (24) and control (15, P = 0.07). There was likewise no significant difference in the prevalence of other benign thyroid gland diseases between the two groups. Only nonmedullary cancer of the thyroid was shown to be statistically more prevalent in HPT patients than in autopsy controls (7% vs 0%, respectively; P < 0.02). The major factor that accounts for the coexistence of benign thyroid lesions and HPT is that both are prevalent in middle-aged women.(ABSTRACT TRUNCATED AT 250 WORDS)

An assessment of residual ovine nematodes on pasture under maritime conditions.

Residual ovine nematode pasture infections were assessed by grazing groups of ewes and their lambs on permanent sheep and cattle pastures and by the use of tracer lambs. Ostertagia spp., Cooperia oncophora, Nematodirus spp., Chabertia ovina and Trichuris spp. eggs and/or larvae survived on pastures overwinter. Second generation Ostertagia larvae were present in greatest numbers on pasture during the latter part of August and early September. The failure of a significant build-up of Cooperia oncophora was attributed to negligible worm egg output of this species in sheep. A build-up of Nematodirus spp. on pasture was not detected in this study.

Evaluation of two management procedures for the control of maedi-visna.

Two control programs were evaluated for their efficiency in eradicating the maedi-visna (M-V) virus from a single sheep flock. In both programs, the agar gel immunodiffusion test was used for the detection of M-V infected animals at regular intervals. In program 1, the test and remove program, ewes that were serologically positive for M-V were immediately removed along with their offspring. The prevalence of infected sheep decreased gradually and a seronegative flock was obtained after 30 months of monitoring. Program 2 entailed the removal of replacement ewe lambs at birth prior to the ingestion of colostrum. Maedi-visna antibodies have not been detected in this flock. These results show that under conditions similar to the industry norms, M-V can be expelled. Although the approach of program 1 is more practical for sheep producers, program 2 is more effective because of the earlier development of a M-V seronegative flock. Because of the nature of the humoral response, a longer time period than four years is required to ensure that M-V has been completely eradicated from each flock.

Essential blepharospasm: nursing update.

Essential blepharospasm is a chronic, potentially disabling disorder for which there is no known cause or cure. The term blepharospasm derives from the Greek word 'blepharon' meaning eyelid and the word 'essential' implies unknown cause. In neurological literature blepharospasm is classed as a focal dystonia. Lack of recognition of the disease may cause patients to consult numerous physicians as well as acupuncturists, chiropractors, faith healers and others in an effort to find a cure to what they are sure is not just a psychological problem. Nurses who are knowledgeable about the disease entity can easily recognize the symptoms. They can also prevent disability by recommending appropriate professional help. Treatment for the control of symptoms has only recently become available. It is the purpose of this discussion to review current information about blepharospasm that has particular relevance for neuroscience nurses in their personal as well as professional lives.

Botulinum toxin for blepharospasm: challenges for rehabilitation nurses.

Blepharospasm is a chronic, progressive, involuntary spasmodic closure of the eyelids associated with abnormal facial and oromandibular movements. It is a neurologic disorder whose cause is unknown and whose pathophysiology is poorly understood. Without appropriate treatment, it can result in functional blindness and other disabilities. In the last decade, botulinum toxin has been found to be effective therapy for most individuals. The drug, which is given by local injection, has a denervation effect. It relieves symptoms for several months, allowing patients to resume their former lifestyles between treatments. This new therapy modality challenges rehabilitation nurses to bridge the gap between disabled persons in the community and this new technology. Casefinding, referrals, and patient education are among the interventions that can help meet this challenge. The major purpose of this article is to inform rehabilitation nurses about how to recognize the symptoms of neurologic blepharospasm and how to intervene to prevent disabilities that could result.

Blepharospasm, hemifacial spasm and the nurse's role.

Blepharospasm and hemifacial spasm are involuntary movement disorders that affect the facial muscles. They are classified as cranial dystonias. Their cause is unknown and the underlying pathophysiology is poorly understood. Both dystonias are more common in women than in men. It is the middle-aged group that is most frequently affected. Because of their high visibility, these disorders may cause considerable distress and embarrassment. Affected persons are often mistakenly considered to have psychiatric problems. In addition, both dystonias may result in severe disability. For example, the person with untreated blepharospasm may experience social isolation and functional blindness. Recently, therapy in the form of botulinum toxin became available in larger centers. Repeated injections of the toxin usually relieves symptoms and enable patients to resume a former lifestyle. Neuroscience nurses who are knowledgeable about cranial dystonias and the resources that are currently available can retard progression of disability and help restore the individual's quality of life. Informed neuroscience nurses can also play an important role in case-finding, counselling and referral. Two examples are presented in order to highlight some of the complexities inherent in the diagnosis and treatment of each type of cranial dystonia and to further clarify the nurse's role. These examples are based on the personal and professional experience of the authors.