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1.
J Genet Couns ; 22(4): 411-21, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23615968

ABSTRACT

Increasing demand for genetic services has resulted in the need to evaluate current service delivery models (SDMs) and consider approaches that improve access to and efficiency of genetic counseling (GC). This study aimed to describe SDMs currently used by the GC community. The NSGC membership was surveyed regarding the use of four SDMs: in-person GC, telephone GC, group GC, and telegenetics GC. Variables related to access and components of use were also surveyed, including: appointment availability, time-per-patient, number of patients seen, billing, and geographic accessiblity. Seven hundred one usable responses were received. Of these, 54.7 % reported using an in-person SDM exclusively. The remainder (45.3 %) reported using multiple SDMs. Telephone, group and telegenetics GC were used often or always by 8.0 %, 3.2 % and 2.2 % of respondents, respectively. Those using an in-person SDM reported the ability to see the highest number of patients per week (p < 0.0001) and were the most likely to bill in some manner (p < 0.0001). Those using telegenetic and telephone GC served patients who lived the furthest away, with 48.3 % and 35.8 %% respectively providing GC to patients who live >4 h away. This study shows that genetic counselors are incorporating SDMs other than traditional in-person genetic counseling, and are utilizing more than one model. These adaptations show a trend toward shorter wait time and shorter length of appointments. Further study is indicated to analyze benefits and limitations of each individual model and factors influencing the choice to adopt particular models into practice.


Subject(s)
Genetic Counseling , Models, Organizational
2.
J Biomech ; 45(15): 2693-7, 2012 Oct 11.
Article in English | MEDLINE | ID: mdl-22871347

ABSTRACT

The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge.


Subject(s)
Intestine, Large/surgery , Models, Biological , Surgical Staplers , Anastomosis, Surgical/methods , Equipment Design , Finite Element Analysis , Stress, Mechanical , Surgical Stapling/methods
3.
J Genet Couns ; 21(5): 645-51, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22566244

ABSTRACT

The Service Delivery Model Task Force (SDMTF) was appointed in 2009 by the leadership of the National Society of Genetic Counselors (NSGC) with a charge to research and assess the capacity of all existing service delivery models to improve access to genetic counseling services in the context of increasing demand for genetic testing and counseling. In approaching this charge, the SDMTF found that there were varying interpretations of what was meant by "service delivery models" and the group held extensive discussions about current practices to arrive at consensus of proposed definitions for current genetic service delivery models, modes of referral and components of service delivery. The major goal of these proposed definitions is to allow for conversations to begin to address the charge to the committee. We propose that current models of service delivery can be defined by: 1) the methods in which genetic counseling services are delivered (In-person, Telephone, Group and Telegenetics), 2) the way they are accessed by patients (Traditional referral, Tandem, Triage, Rescue and Self-referral) and 3) the variable components that depend upon multiple factors unique to each service setting. This report by the SDMTF provides a starting point whereby standardized terminology can be used in future studies that assess the effectiveness of these described models to overcome barriers to access to genetic counseling services.


Subject(s)
Genetic Counseling , Models, Organizational , Genetic Testing , Humans , Workforce
4.
J Genet Couns ; 21(2): 151-61, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22134580

ABSTRACT

Updated from their original publication in 2004, these cancer genetic counseling recommendations describe the medical, psychosocial, and ethical ramifications of counseling at-risk individuals through genetic cancer risk assessment with or without genetic testing. They were developed by members of the Practice Issues Subcommittee of the National Society of Genetic Counselors Familial Cancer Risk Counseling Special Interest Group. The information contained in this document is derived from extensive review of the current literature on cancer genetic risk assessment and counseling as well as the personal expertise of genetic counselors specializing in cancer genetics. The recommendations are intended to provide information about the process of genetic counseling and risk assessment for hereditary cancer disorders rather than specific information about individual syndromes. Essential components include the intake, cancer risk assessment, genetic testing for an inherited cancer syndrome, informed consent, disclosure of genetic test results, and psychosocial assessment. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care provider's professional judgment based on the clinical circumstances of a client.


Subject(s)
Genetic Counseling , Genetic Testing , Neoplasms/genetics , Risk Assessment , Genetic Predisposition to Disease , Humans , Workforce
5.
Vet Comp Orthop Traumatol ; 24(4): 257-61, 2011.
Article in English | MEDLINE | ID: mdl-21597646

ABSTRACT

An in vitro mechanical study was performed to compare the stiffness, maximum load, and cyclic load-to-failure of a new external fixation half-pin design utilizing a tapered thread-run-out (TRO) feature with currently available positive profile thread (PP) half-pins. Five different sizes of each of the two pin types were evaluated. Under static loading, TRO pins were significantly stiffer and had a higher maximum load compared to the similar sized PP pins (p <0.0001 for all comparisons). In cyclic fatigue testing, TRO pins lasted 2.3- to 4.9-fold more cycles than PP pins of similar size (p <0.0001 for all comparisons). The increased pin stiffness and improved cyclic lifespan provided by TRO pins may be especially valuable in the stabilization of biologically and mechanically challenging fracture cases where healing is prolonged.


Subject(s)
Bone Nails/veterinary , External Fixators/veterinary , Fractures, Bone/veterinary , Animals , Fractures, Bone/surgery , Mechanics
6.
Cancer ; 100(1): 53-64, 2004 Jan 01.
Article in English | MEDLINE | ID: mdl-14692024

ABSTRACT

BACKGROUND: To the authors' knowledge, hereditary nonpolyposis colorectal carcinoma (HNPCC) is the most commonly occurring hereditary disorder that predisposes to colorectal carcinoma (CRC), accounting for approximately 2-7% of all CRC cases diagnosed in the U.S each year. Its diagnosis is wholly dependent on a meticulously obtained family history of cancer of all anatomic sites, with particular attention to the pattern of cancer distribution within the family. METHODS: The objective of the current study was to illustrate various vexing problems that can deter the diagnosis of HNPCC and, ultimately, its management. This was an observational cohort study. Sixteen HNPCC and HNPCC-like families were selected from a large resource of highly extended HNPCC families. High-risk patients were selected from these HNPCC families. An ascertainment bias was imposed by the lack of a population-based data set. Personal interviews and questionnaires were used for data collection. RESULTS: There was an array of difficulties highlighted by limitations in compliance, lack of a clinical or molecular basis for an HNPCC diagnosis, ambiguous DNA findings, problems in genetic counseling, failure to meet Amsterdam or Bethesda criteria, small families, lack of medical and pathologic documentation, poor cooperation of family members and/or their physicians, cultural barriers, economic stress, frequent patient fear and anxiety, perception of insurance discrimination, and limited patient and/or physician knowledge regarding hereditary cancer. CONCLUSIONS: The diagnosis and management of HNPCC is predicated on physician knowledge of its phenotypic and genotypic heterogeneity, in concert with the multifaceted problems that impact on patient compliance.


Subject(s)
Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis , Colorectal Neoplasms, Hereditary Nonpolyposis/therapy , Diagnostic Errors , Genetic Testing , Guideline Adherence , Adult , Aged , Aged, 80 and over , Anxiety , Cohort Studies , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , Cultural Characteristics , DNA, Neoplasm , Diagnosis, Differential , Family Health , Female , Genetic Counseling , Genotype , Health Knowledge, Attitudes, Practice , Humans , Male , Middle Aged , Patient Compliance , Pedigree , Phenotype , Practice Patterns, Physicians' , Risk Factors
7.
J Clin Oncol ; 21(4): 740-53, 2003 Feb 15.
Article in English | MEDLINE | ID: mdl-12586815

ABSTRACT

PURPOSE: To provide practical considerations for diagnosing, counseling, and managing patients at high risk for hereditary breast cancer. DESIGN: We have studied 98 extended hereditary breast cancer (HBC)/hereditary breast-ovarian cancer (HBOC) families with BRCA1/2 germline mutations. From these families, 1,315 individuals were counseled and sampled for DNA testing. Herein, 716 of these individuals received their DNA test results in concert with genetic counseling. Several challenging pedigrees were selected from Creighton University's hereditary cancer family registry, as well as one family from Evanston/Northwestern Healthcare, to be discussed in this present report. RESULTS: Many obstacles were identified in diagnosis, counseling, and managing patients at high risk for HBC/HBOC. These obstacles were early noncancer death of key relatives, perception of insurance or employment discrimination, fear, anxiety, apprehension, reduced gene penetrance, and poor compliance. Other important issues such as physician culpability and malpractice implications for failure to collect or act on the cancer family history were identified. CONCLUSION: When clinical gene testing emerged for BRCA1 and BRCA2, little was known about the efficacy of medical interventions. Potential barriers to uptake of testing were largely unexplored. Identification and referral of high-risk patients and families to genetic counseling can greatly enhance the care of the population at the highest risk for cancer. However, because premonitory physical stigmata are absent in most of these syndromes, an HBOC diagnosis may be missed unless a careful family history of cancer of the breast, ovary, or several integrally associated cancers is obtained.


Subject(s)
Breast Neoplasms, Male/genetics , Breast Neoplasms/genetics , Medical Oncology , Ovarian Neoplasms/genetics , Pedigree , Physician's Role , Adult , Breast Neoplasms/diagnosis , Breast Neoplasms, Male/diagnosis , Counseling , Female , Genes, BRCA1 , Genes, BRCA2 , Germ-Line Mutation , Humans , Male , Ovarian Neoplasms/diagnosis , Risk Factors
8.
Ultrasound Med Biol ; 27(6): 861-7, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11516546

ABSTRACT

In humans, bone strength is assessed indirectly by the noninvasive measurement of structure or mass. Recent clinical application of an ultrasonic critical-angle reflectometry technique (UCR) has demonstrated the measurement of the regional and directional distribution of mechanical stiffness. This study investigates the specific question: are these measurements of a local material level property predictive of the strength of whole bone? Maximum values of pressure wave velocity and breaking strength were recorded at two locations (midshaft and base of neck) on rat femurs from growing rats. The results demonstrate a strong empirical relationship between material-level ultrasound (US) velocity and whole bone mechanical strength. However, the US velocity at a specific bone site can be used to assess bone strength at that site only, explaining discrepancies in other published studies that negate a relationship between strength and US velocity. The results indicate an important role for US velocity measurement in clinical evaluation of bone health.


Subject(s)
Bone and Bones/diagnostic imaging , Animals , Biomechanical Phenomena , Bone Development , Bone and Bones/physiology , Female , Femur/diagnostic imaging , Femur/physiology , In Vitro Techniques , Ovariectomy , Rats , Ultrasonography
9.
Vet Surg ; 30(4): 386-94, 2001.
Article in English | MEDLINE | ID: mdl-11443601

ABSTRACT

OBJECTIVE: Evaluate the effects of varying ring diameter, wire tension, and wire-divergence angle on the axial stiffness characteristics of circular external skeletal fixator single-ring constructs. Study Design-Biomechanical evaluation using circular fixator components and a Delrin cylinder bone model. METHODS: Single ring constructs using two 1.6 mm diameter Kirschner wires to secure a 19 mm Delrin cylinder centered within the ring were examined. Component variables evaluated were ring diameter (50 mm, 66 mm, 84 mm, and 118 mm), wire-divergence angle (30 degrees, 60 degrees, and 90 degrees ), and wire tension (0 kg, 30 kg, 60 kg, and 90 kg). A total of 48 constructs were examined. Rings were rigidly mounted on a universal testing system and the cylinder loaded in axial compression (7.4 N/s) to 220 N. Load/displacement curves were analyzed to determine the following: the displacement (mm) that occurred before the slope of each load/displacement curve became linear, the stiffness (N/mm) of the linear portion of each load/deformation curve, and the total displacement (mm) produced at maximal load. Least-squares linear regression was used to model response variables as linear functions of ring diameter, wire divergence angle, and wire tension. Three-way interactions and 2-way interactions among independent component variables were evaluated first in the modeling process and included in a best model if response variables were found to have statistically significant regression coefficients. The regression coefficients and corresponding standard errors and covariances were used to estimate the maximal effect and standard error attributable to wire divergency angle (change from 30 degrees to 90 degrees ) and wire tension (change from 0 to 90 kg) for each ring diameter. RESULTS: All load/deformation curves had an initial exponential increase in stiffness, with the slope becoming linear at higher loads. The exponential phase was more pronounced in larger-diameter ring constructs and was mitigated by tensioning the wires. Ring diameter had the greatest influence on displacement that occurred before the curve became linear (semipartial r(2) [sp-r2] = .89), stiffness (sp-r2 = .94), and total displacement (sp-r2 = .93). Wire tension exerted a smaller influence on displacement that occurred before the curve became linear (sp-r2 =.06), stiffness (sp-r2 = .03), and total displacement (sp-r2 = .05). Wire divergence angle had a nominal effect on displacement that occurred before the curve became linear (sp-r2 = .0001), on stiffness (sp-r2 = .004), and on total displacement (sp-r2 =.003). CONCLUSIONS: Ring diameter had a profound effect on the axial stiffness characteristic of single ring constructs. Tensioning of the fixation wires can improve the axial stiffness characteristics of these constructs, particularly in larger diameter ring constructs, by mitigating the initial exponential phase of the load/deformation curve. Wire divergence angle had only a nominal differential effect on axial stability. CLINICAL RELEVANCE: Understanding how individual component variables and their interactions influence bone segment stability should help surgeons to optimize interfragmentary strain. Tensioning fixation wires is probably unnecessary in 50 mm diameter ring constructs, but assumes greater importance as ring diameter increases.


Subject(s)
Cats/surgery , Dogs/surgery , External Fixators/veterinary , Fracture Fixation/veterinary , Fractures, Bone/veterinary , Animals , Biomechanical Phenomena , Cats/injuries , Dogs/injuries , Equipment Design/veterinary , Fracture Fixation/instrumentation
10.
J Spinal Disord ; 14(3): 232-6, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11389374

ABSTRACT

This study involved the mechanical testing of single-rod segmental hook fixation and double-rod segmental hook fixation in a long-segment animal model. The goals were first to compare the flexibility of a single-rod scoliosis construct with that of a double-rod construct when tested in torsion, and second, to determine the effect of not using instrumentation with every vertebral segment for the single rod. Another study found that the single-rod construct was as stiff in torsion as the standard double-rod construct in a model of 10 vertebral segments. The amount of neutral zone (NZ) rotation was tested in five calf spines using an MTS (Material Testing System) machine. Five constructs were tested and included 1) a single rod with hooks at every level except the apex; 2) a single rod with two fewer hooks; 3) a single rod with four fewer hooks; 4) a double-rod construct; and 5) no instrumentation. The amount of NZ rotation between vertebral segments was measured over 12, 10, 8, 6, 4, and 2 vertebral segments. An analysis of variance with all constructs showed that the instrumented spines had significantly less movement than did the uninstrumented spine. Statistical comparison using analysis of variance of constructs (constructs 1 to 4) showed that over 12 vertebral segments (T4-L3), all single-rod constructs (constructs 1 to 3) allowed more NZ rotation than did the standard double-rod construct. This testing indicated that over 12 vertebral segments the single rod allowed more NZ rotation than a double-rod construct.


Subject(s)
Bone Nails/standards , Materials Testing , Orthopedic Fixation Devices/standards , Spine/surgery , Animals , Biomechanical Phenomena , Cattle , Pliability , Range of Motion, Articular , Rotation , Spine/physiopathology , Torsion Abnormality
11.
Gen Hosp Psychiatry ; 23(2): 84-9, 2001.
Article in English | MEDLINE | ID: mdl-11313076

ABSTRACT

The objective of this article was to estimate the incidence of delirium in a sample of patients undergoing elective surgery and to identify the preoperative factors most closely associated with developing this complication. Consecutive patients (n=500) underwent a full preoperative medical evaluation including assessment of cognitive and functional status. Daily evaluation on postoperative days 1 through 4 included medical record review and direct standardized patient interviews. Logistic regression was used to explore the associations between preoperative factors and postoperative delirium. Delirium was detected in 57 (11.4%) patients. Univariate factors associated with delirium included age> or =70 years (RR=3.1 [1.75,5.55]), preexisting cognitive impairment (RR=3.1 [1.73, 5.43]), greater preoperative functional limitations (RR=1.57 [1.27, 1.94]), and a history of prior delirium (RR 4.1 [1.98 to 8.27]. Adjusting for other factors, previous delirium (OR=4.08 [1.85, 9.0]), age> or =70 years (OR=3.2 [1.6, 6.0], and preexisting cognitive impairment (OR=2.16 [1.15, 4.0] remained predictive of delirium. Patients' perceptions that alcohol had affected their health (OR=6.53 [1.58 to 28.1]) and use of narcotic analgesics just prior to admission (OR=2.7 [1.37 to 5.3]) were also significantly associated with delirium postoperatively. Several easily obtained preoperative clinical factors can be used to identify patients at risk for postoperative delirium. This approach, when combined with specialized delirium teams using established guidelines, may be more effective in targeting patients at risk, thus reducing the number of episodes and days of delirium.


Subject(s)
Delirium/epidemiology , Delirium/etiology , Elective Surgical Procedures/adverse effects , Postoperative Complications , Age Factors , Aged , Alcohol Withdrawal Delirium/epidemiology , Alcohol Withdrawal Delirium/etiology , Analgesics, Opioid/administration & dosage , Cognition Disorders , Delirium/diagnosis , Delirium/prevention & control , Female , Humans , Incidence , Male , Middle Aged , Odds Ratio , Ohio/epidemiology , Population Surveillance , Prospective Studies , Psychiatric Status Rating Scales , Risk Factors
12.
Psychosomatics ; 42(1): 68-73, 2001.
Article in English | MEDLINE | ID: mdl-11161124

ABSTRACT

The authors identified the added cost attributable to postoperative delirium in patients undergoing elective surgery. The authors evaluated patients (n = 500) before their elective surgery, assessing cognitive functioning, medical conditions, medication usage, and other information regarding their health status. Using DSM-IV criteria, the authors assessed patients for delirium on Postoperative Days 1-4. Medical record review provided laboratory, radiological, and pharmaceutical information. The authors analyzed length of stay (LOS), comprehensive cost data collected through the hospital, and a group practice financial database to determine differences among those developing delirium. Of the 500 patients assessed, 57 (11.4%) developed delirium during the study. Delirium is an extremely costly disorder, both to the patient in terms of morbidity and mortality and to the medical facility. A prolonged LOS increases charges to third party payors and reduces return to physicians and hospitals when delirium develops. Careful presurgical screening and targeted postoperative interventions may help contain LOS and costs while affording greater physical, emotional, and cognitive health to patients hospitalized for elective surgery.


Subject(s)
Cost of Illness , Delirium/economics , Postoperative Complications/economics , Surgical Procedures, Operative/psychology , Aged , Delirium/diagnosis , Delirium/epidemiology , Female , Humans , Length of Stay/statistics & numerical data , Male , Middle Aged , Postoperative Complications/diagnosis , Postoperative Complications/epidemiology , Regression Analysis , Statistics, Nonparametric
13.
J Am Acad Dermatol ; 40(6 Pt 1): 999-1001, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10365935

ABSTRACT

Eyelid tattooing is a commonly performed procedure. For at least 100 years, it has been performed by medical and nonmedical professionals. Complications can occur; the main one is improperly placed pigment. To date, the most frequently reported methods to remove eyeliner tattoos have been laser treatments or surgical correction. We observed a case in which tretinoin was used successfully in the removal of an eyelid tattoo.


Subject(s)
Eyelids , Tattooing , Tretinoin/administration & dosage , Adult , Female , Humans
14.
J Biol Chem ; 274(10): 6526-35, 1999 Mar 05.
Article in English | MEDLINE | ID: mdl-10037746

ABSTRACT

The mammalian retina contains at least two guanylyl cyclases (GC1 and GC2) and two guanylyl cyclase-activating proteins (GCAP1 and GCAP2). Here we present evidence of the presence of a new photoreceptor-specific GCAP, termed GCAP3, which is closely related to GCAP1. The sequence similarity of GCAP3 with GCAP1 and GCAP2 is 57 and 49%, respectively. Recombinant GCAP3 and GCAP2 stimulate GC1 and GC2 in low [Ca2+]free and inhibit GCs when [Ca2+]free is elevated, unlike GCAP1, which only stimulates GC1. GCAP3 is encoded by a distinct gene present in other mammalian species but could not be detected by genomic Southern blotting in rodents, amphibians, and lower vertebrates. The intron/exon arrangement of the GCAP3 gene is identical to that of the other GCAP genes. While the GCAP1 and GCAP2 genes are arranged in a tail-to-tail array on chromosome 6p in human, the GCAP3 gene is located on 3q13.1, suggesting an ancestral gene duplication/translocation event. The identification of multiple Ca2+-binding proteins that interact with GC is suggestive of complex regulatory mechanisms for photoreceptor GC.


Subject(s)
Calcium-Binding Proteins/genetics , Guanylate Cyclase/metabolism , Photoreceptor Cells/metabolism , Amino Acid Sequence , Animals , Calcium-Binding Proteins/metabolism , Cloning, Molecular , Gene Expression Regulation , Guanylate Cyclase-Activating Proteins , Humans , Molecular Sequence Data , Nerve Tissue Proteins/genetics , Retina/metabolism , Sequence Alignment , Sequence Analysis , Species Specificity
16.
Spine (Phila Pa 1976) ; 23(5): 530-5; discussion 536, 1998 Mar 01.
Article in English | MEDLINE | ID: mdl-9530783

ABSTRACT

STUDY DESIGN: A biomechanical assessment of anterior release and discectomy in the thoracic spine was performed on an animal model using thoracoscopic and open thoracotomy techniques. OBJECTIVES: To compare the relative efficacy of these two techniques of release in achieving increased spinal mobility. BACKGROUND DATA: The clinical use of video-assisted thoracoscopy in the correction of spinal deformity is increasing. The effectiveness of thoracoscopic anterior spinal release with discectomy has not been evaluated biomechanically. METHODS: Anterior release with discectomy was performed on six midthoracic motion segments in five mature goats. The thoracoscopic technique was used for three levels on one side, and an open thoracotomy was used for the alternating three levels of the contralateral side. The duration of surgery for disc excision and the amount of blood loss for each technique were recorded. The intact cranial and caudal motion segments served as controls. The motion segments were individually subjected to nondestructive biomechanical testing. Torsional, sagittal, and coronal bending torques were applied, and the resulting angular displacement was measured. RESULTS: The duration of surgery to remove a disc thoracoscopically decreased as experience was gained by the surgeon. The amount of intraoperative blood loss was comparable using the two methods. There was significantly increased flexibility in the released segments with both techniques, compared with the flexibility in the intact levels for all three loading directions. There was no difference in the motion obtained after release between the two techniques. CONCLUSION: Open and thoracoscopic anterior release and discectomy have been demonstrated, through biomechanical in vitro testing, to increase the flexibility of the spine to a similar extent.


Subject(s)
Diskectomy/methods , Thoracic Vertebrae/physiology , Thoracoscopy/methods , Animals , Biomechanical Phenomena , Blood Loss, Surgical , Goats , Joints/physiology , Range of Motion, Articular , Scoliosis/surgery , Thoracic Vertebrae/surgery , Time Factors
17.
Eur J Biochem ; 252(3): 591-9, 1998 Mar 15.
Article in English | MEDLINE | ID: mdl-9546678

ABSTRACT

Two guanylate-cyclase-activating proteins (GCAP) encoded by a tail-to-tail gene array have been characterized in the mammalian retina. Using frog retina as a model, we obtained evidence for the presence of a photoreceptor Ca2+-binding protein closely related to GCAP. This protein (206 amino acids) does not stimulate guanylate cyclase (GC) in low [Ca2+], but inhibits GC in high [Ca2+], and is therefore termed guanylate-cyclase-inhibitory protein (GCIP). Sequence analysis indicates that GCIP and GCAP1 and GCAP2 have diverged substantially, but conserved domains present in all vertebrate GCAP are present in GCIP. Moreover, partial characterization of the GCIP gene showed that the positions of two introns in the GCIP gene are identical to positions of corresponding introns of the mammalian GCAP gene array. As to the major differences between GCIP and GCAP, the fourth EF hand Ca2+-binding motif of GCIP is disabled for Ca2+ binding, and GCIP does not stimulate GC. Monoclonal and polyclonal antibodies raised against recombinant GCIP identified high levels of GCIP in the inner segments, somata and synaptic terminals of frog cone photoreceptors. The results suggest that GCIP is a Ca2+-binding protein of the GCAP/recoverin subfamily. Its localization in frog cones closely resembles that of GC in mammalian cones. GCIP inhibits GC at high free [Ca2+], competing with GCAP1 and GCAP2 for GC regulatory sites.


Subject(s)
Calcium-Binding Proteins/chemistry , Calcium-Binding Proteins/metabolism , Retina/metabolism , Amino Acid Sequence , Animals , Base Sequence , Cattle , Cloning, Molecular , DNA Primers , Gene Library , Guanylate Cyclase-Activating Proteins , Mammals , Molecular Sequence Data , Photoreceptor Cells/metabolism , Protein Structure, Secondary , Rana pipiens , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Rod Cell Outer Segment/metabolism , Sequence Alignment , Sequence Homology, Amino Acid
18.
Cancer Res ; 57(2): 209-14, 1997 Jan 15.
Article in English | MEDLINE | ID: mdl-9000556

ABSTRACT

The mutational expansion of triplet repeat microsatellite sequences underlies the transmission of a number of heritable neurological disorders. However, this form of microsatellite instability has not previously been observed in association with malignant disease. Because trinucleotide expansions can dramatically alter gene expression and protein function, we hypothesized that they might occur in neoplastic cells as a mechanism through which to alter cancer genes. Accordingly, we used the repeat expansion detection technique to determine whether (CAG)n triplet repeat expansions were present in DNA from malignant cells. No expansions were observed in a survey of 20 tumor cell lines derived from neoplasms of the breast, ovary, cervix, endometrium, lung, colon, placenta, or hematopoietic system. However, we did observe expanded (CAG)n tracts in DNA from 5 of 11 testicular tumor cell lines and in 1 of 11 sporadic testicular tumors. Examination of the corresponding normal DNA, when available, revealed that some of the expansions were germline in nature. To assess the possibility that (CAG)n expansions underlie some cases of inherited testicular cancer, we also analyzed germline DNA from members of five kindreds predisposed to this malignancy. An increase in (CAG)n tract size was observed in all five families and was particularly striking in one large pedigree in which expansions were observed in three of four affected siblings. These observations raise the possibility that the germline transmission of expanded (CAG)n tracts may play a role in testicular tumorigenesis.


Subject(s)
DNA, Neoplasm/genetics , Pedigree , Testicular Neoplasms/genetics , Trinucleotide Repeats/genetics , Adenine , Autoradiography , Cytosine , Female , Guanine , Humans , Male , Oligonucleotide Probes/genetics , Ovarian Neoplasms/genetics , Polymerase Chain Reaction , Tumor Cells, Cultured
20.
Virology ; 217(1): 1-10, 1996 Mar 01.
Article in English | MEDLINE | ID: mdl-8599193

ABSTRACT

Nucleotide sequence comparisons of the pol gene among 47 retroelements identified two very conserved regions, separated by a span of approximately 640 bp, that have not been previously reported. A set of mixed oligonucleotide primers, 5'-MOP-2 and 3'-MOP-2, homologous to these two conserved pol regions was constructed for use in detection of retroelements. When MOPs-2 were employed in PCR amplification studies, products of about 0.64 kb in size were amplified from human and mouse genomic DNAs and from HIV-1 proviral DNA, but not from negative control plasmid DNAs. The PCR products amplified with MOPs-2 from human LuC-1 teratocarcinoma cell DNA were subcloned and sequenced. Five clones of approximately 0.64 kb in size were identified, and sequence comparisons with all entries in GenBank indicated that these five clones have highest homology, in a range of 64.31 to 98.65%, with the corresponding pol region of HERV-K10 and HM-16 of the human endogenous retrovirus-K (HERV-K) family. Southern hybridizations at high stringency demonstrated that these five clones are present in all human DNAs tested. The evolutionary relationships of these clones with the equivalent pol region of other retroelements were defined by phylogenetic analyses that placed three clones into the HERV-K family and two clones into a new family of human endogenous retroelements. In addition, clone HERV-(K)73 contains the smaller PV1b pol segment that was reported to be selectively expressed in blood leukocytes of patients with polycythemia vera.


Subject(s)
Genes, pol , Retroviridae/genetics , Amino Acid Sequence , Animals , Base Sequence , Cell Line , DNA Primers , DNA, Viral , Genome, Viral , Humans , Mice , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , Retroviridae/isolation & purification , Tumor Cells, Cultured
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