Neurite extension and neuronal survival activities of recombinant S100 beta proteins that differ in the content and position of cysteine residues.

S100 beta produced in Escherichia coli from a synthetic gene (Van Eldik, L. J., J. L. Staecker, and F. Winningham-Major. 1988. J. Biol. Chem. 263:7830-7837) stimulates neurite outgrowth and enhances cell maintenance in cultures of embryonic chick cerebral cortex neurons. In control experiments, the neurite extension activity is reduced by preincubation with antibodies made against bovine brain S100 beta. When either of the two cysteines in S100 beta are altered by site-directed mutagenesis, the resultant proteins maintain the overall biochemical properties of S100 beta, but lose both the neurite extension and neuronal survival activities. However, another S100 beta mutant, in which the relative position of one of the two cysteines was changed, had neurotrophic activity similar to that of the unmodified protein. These and other results indicate that (a) specific neurite extension activity and neuronal survival activity are two related activities inherent to the S100 beta molecule; (b) a disulfide-linked form of S100 beta is required for full biological activity, and (c) the relative position of the cysteines can be modified. These data suggest potential in vivo roles for S100 beta in the development and maintenance of neuronal function in the central nervous system, and demonstrate the feasibility of the longer term development of selective pharmacological agents based on the S100 beta structure.

The combination of symbolic and numerical computation for three-dimensional modeling of RNA.

Three-dimensional (3-D) structural models of RNA are essential for understanding of the cellular roles played by RNA. Such models have been obtained by a technique based on a constraint satisfaction algorithm that allows for the facile incorporation of secondary and other structural information. The program generates 3-D structures of RNA with atomic-level resolution that can be refined by numerical techniques such as energy minimization. The precision of this technique was evaluated by comparing predicted transfer RNA loop and RNA pseudoknot structures with known or consensus structures. The root-mean-square deviation (2.0 to 3.0 angstroms before minimization) between predicted and control structures reveal this system to be an effective method in modeling RNA.

Computational methods for RNA structure determination.

During the past year, major improvements have been made in methods used to solve RNA structures from crystals, find RNA patterns in sequence data and determine RNA secondary structure. Computational methods for assisting an interactive computer graphics human modeler, searching the conformational space of RNA tertiary structure, studying the dynamics of complexes involving RNA and simulating RNA catalytic activities have also been advanced.

Pseudoknots in prion protein mRNAs confirmed by comparative sequence analysis and pattern searching.

The human prion gene contains five copies of a 24 nt repeat that is highly conserved among species. An analysis of folding free energies of the human prion mRNA, in particular in the repeat region, suggested biased codon selection and the presence of RNA patterns. In particular, pseudoknots, similar to the one predicted by Wills in the human prion mRNA, were identified in the repeat region of all available prion mRNAs available in GenBank, but not those of birds and the red slider turtle. An alignment of these mRNAs, which share low sequence homology, shows several co-variations that maintain the pseudoknot pattern. The presence of pseudoknots in yeast Sup35p and Rnq1 suggests acquisition in the prokaryotic era. Computer generated three-dimensional structures of the human prion pseudoknot highlight protein and RNA interaction domains, which suggest a possible effect in prion protein translation. The role of pseudoknots in prion diseases is discussed as individuals with extra copies of the 24 nt repeat develop the familial form of Creutzfeldt-Jakob disease.

High-dose megestrol acetate in advanced or recurrent endometrial carcinoma: a Gynecologic Oncology Group Study.

PURPOSE: Progestins represent the most widely used form of endocrine therapy in advanced or recurrent endometrial carcinoma. Based on encouraging response rates in breast cancer with high-dose megestrol acetate (MA) 800 mg/d, this phase II trial assessed response rates in patients with endometrial carcinoma treated with high-dose MA. PATIENTS AND METHODS: Sixty-three patients with recurrent or advanced endometrial carcinoma were entered into this Gynecologic Oncology Group (GOG) study. Patients had either failed to respond to or were considered incurable with local therapy and had not received prior cytotoxic or hormonal therapy. MA 800 mg/d was administered orally in divided doses. Standard GOG toxicity criteria were used. RESULTS: Of 63 patients entered, 58 were assessable for toxicity and 54 for response. Of 13 responders (24%), six (11%) had a complete and seven (13%) a partial response. Four of the responses lasted greater than 18 months. Twelve patients (22%) had stable disease. The response rate of patients with grade 1 or 2 lesions (11 of 30, 37%) was significantly higher (P = .02) than that of patients with more poorly differentiated tumors (two of 24, 8%). There was no difference in response rates comparing advanced versus recurrent disease, cell type, including papillary serous lesions, site of disease, prior radiation, age, or weight. The median progression-free survival (PFS) and overall survival intervals were 2.5 and 7.6 months, respectively. Grade 3 weight gain (> 20%) was seen in three patients and grade 3/4 hyperglycemia in three. Three deaths secondary to cardiovascular events were possibly related to therapy; diabetes was also a contributing factor in all three cases. CONCLUSION: High-dose MA is active in endometrial carcinoma, but appears to have no advantage over lower-dose progestins.

Randomized trial of three cisplatin dose schedules in squamous-cell carcinoma of the cervix: a Gynecologic Oncology Group study.

The Gynecologic Oncology Group has conducted a randomized prospective trial comparing cisplatin 50 mg/m2 every 21 days (regimen 1), 100 mg/m2 every 21 days (regimen 2), and cisplatin 20 mg/m2 for five consecutive days repeated every 21 days (regimen 3). Four hundred ninety-seven evaluable patients have been accrued on this study. The response rates were 20.7%, 31.4%, and 25.0%, for regimens 1, 2, and 3, respectively; the complete remission rates were 10.0%, 12.7%, and 8.6% for regimens 1, 2, and 3, respectively. The median duration of response ranged from 3.9 to 4.8 months, the median progression-free interval from 3.7 to 4.6 months, and the median survival time from 6.1 to 7.1 months. The difference in response rates for regimens 1 and 2 is statistically significant (P = .015) but less than the magnitude originally considered clinically significant. The differences in complete remission rates, response duration, progression-free interval, and survival times are not statistically significant. The following types of toxicity were observed: serum creatinine level greater than 2 mg/dL and/or BUN level greater than 40 mg/dL was 7%, 14%, and 17% on regimens 1, 2, and 3, respectively; leukocyte count less than 4,000/microL was 27%, 44%, and 41% on regimens 1, 2, and 3, respectively. Nausea and vomiting occurred in 74 patients (83%). The regimen consisting of a 100-mg/m2 single dose has produced a statistically significant higher response rate than the 50 mg/m2 regimen while producing no appreciable differences in complete remission rate, response duration, progression-free interval, or survival. In addition, the higher dose regimen was associated with greater myelosuppression and nephrotoxicity.

Long-term follow-up and prognostic factor analysis in advanced ovarian carcinoma: the Gynecologic Oncology Group experience.

Long-term follow-up was obtained on 726 women with advanced ovarian carcinoma (suboptimal stage III and stage IV) who had received primary chemotherapy on two Gynecologic Oncology Group (GOG) protocols between 1976 and 1982. The first study compared melphalan alone versus melphalan plus hexamethylmelamine versus cyclophosphamide plus doxorubicin (CA). The second study evaluated the same CA regimen with or without cisplatin. Eligibility for the two studies was the same. At last contact, 76 patients were alive. In a multivariate analysis, cell type other than clear cell or mucinous, cisplatin-based treatment, good performance status, younger age, lower stage, clinically nonmeasurable disease, smaller residual tumor volume, and absence of ascites were favorable characteristics for overall survival (P less than .05). Second-look laparotomy was negative significantly more often among those with endometrioid tumors; there were no negative second-look laparotomies among those with mucinous or clear cell tumors. There were 30 patients with suboptimal stage III disease who had a negative second-look laparotomy; 18 (60%) have experienced recurrence, and 13 (43%) have died. Although cisplatin treatment was beneficial, new treatments are clearly needed.

A randomized clinical trial of adjuvant adriamycin in uterine sarcomas: a Gynecologic Oncology Group Study.

After hysterectomy, 156 evaluable patients with stage I (limited to the corpus) or stage II (limited to the corpus and cervix) uterine sarcomas were randomly assigned to adjuvant chemotherapy with Adriamycin (Adria Laboratories, Columbus, Ohio) for six months or to no further treatment. Pelvic irradiation (external or intracavitary) was optional before randomization. Of 75 patients receiving Adriamycin, 31 have suffered recurrences compared with 43 of 81 receiving no adjuvant chemotherapy. This difference is not statistically significant. Moreover, there is no difference in progression-free interval or survival. The optional radiotherapy did not influence the outcome although there was a suggestion that vaginal recurrence was decreased by pelvic radiotherapy. The recurrence rates in specific cell types (leiomyosarcoma, homologous mixed mesodermal sarcoma, or heterologous mixed mesodermal sarcoma) were not significantly different although the pattern of recurrence differed, with pulmonary metastases being more common in leiomyosarcoma and extrapulmonary recurrence being more common in mixed mesodermal sarcoma. The outcome with respect to chemotherapy was not altered even after adjusting for maldistribution of cases. Thus, we could not show a benefit for this dose schedule of Adriamycin as adjuvant treatment for uterine sarcomas.

Quantitative analysis of nucleic acid three-dimensional structures.

A new computer program to annotate DNA and RNA three-dimensional structures, MC-Annotate, is introduced. The goals of annotation are to efficiently extract and manipulate structural information, to simplify further structural analyses and searches, and to objectively represent structural knowledge. The input of MC-Annotate is a PDB formatted DNA or RNA three-dimensional structure. The output of MC-Annotate is composed of a structural graph that contains the annotations, and a series of HTML documents, one for each nucleotide conformation and base-base interaction present in the input structure. The atomic coordinates of all nucleotides and the homogeneous transformation matrices of all base-base interactions are stored in the structural graph. Symbolic classifications of nucleotide conformations, using sugar puckering modes and nitrogen base orientations around the glycosyl bond, and base-base interactions, using stacking and hydrogen bonding information, are introduced. Peculiarity factors of nucleotide conformations and base-base interactions are defined to indicate their marginalities with all other examples. The peculiarity factors allow us to identify irregular regions and possible stereochemical errors in 3-D structures without interactive visualization. The annotations attached to each nucleotide conformation include its class, its torsion angles, a distribution of the root-mean-square deviations with examples of the same class, the list of examples of the same class, and its peculiarity value. The annotations attached to each base-base interaction include its class, a distribution of distances with examples of the same class, the list of examples of the same class, and its peculiarity value. The distance between two homogeneous transformation matrices is evaluated using a new metric that distinguishes between the rotation and the translation of a transformation matrix in the context of nitrogen bases. MC-Annotate was used to build databases of nucleotide conformations and base-base interactions. It was applied to the ribosomal RNA fragment that binds to protein L11, which annotations revealed peculiar nucleotide conformations and base-base interactions in the regions where the RNA contacts the protein. The question of whether the current database of RNA three-dimensional structures is complete is addressed.

Modeling the three-dimensional structure of RNA using discrete nucleotide conformational sets.

The flexibility about seven torsion angles in nucleotides constitutes a severe obstacle to computer modeling of RNA. The computational feasibility of RNA conformational searches can be enhanced by assigning to each nucleotide a set of discrete conformations. In this work, four types of discrete conformational sets for the atomic representation of nucleotide structures were defined and evaluated. These sets, comprising between 10 and 30 conformations, were tested for their ability to reproduce known RNA structures and to generate structures responding to new specifications. Conformational searches were performed with the MC-SYM program, which allows for the generation of all structures satisfying a predetermined set of three-dimensional constraints in a given discrete space. Results with known hairpin loop structures show that root-mean-square deviations of about 1.5 A for backbone atoms and about 2.0 A for all atoms between the modeled and X-ray crystal structures can be expected. The conformational set that gives the most faithful representation of test structures is based on the classification of nucleotide conformations derived from a structural database. Representative conformations are selected from each class that adequately sample variations in backbone direction, sugar pucker and base orientation. With this conformational set, most of the important features of test hairpin structures are reproduced with fidelity, indicating that biologically useful models can be constructed from the combination of discrete nucleotide conformations and an algorithm that rapidly and systematically scans the pre-defined conformational space.

The hairpin ribozyme substrate binding-domain: a highly constrained D-shaped conformation.

The two domains of the hairpin ribozyme-substrate complex, usually depicted as straight structural elements, must interact with one another in order to form an active conformation. Little is known about the internal geometry of the individual domains in an active docked complex. Using various crosslinking and structural approaches in conjunction with molecular modeling (constraint-satisfaction program MC-SYM), we have investigated the conformation of the substrate-binding domain in the context of the active docked ribozyme-substrate complex. The model generated by MC-SYM showed that the domain is not straight but adopts a bent conformation (D-shaped) in the docked state of the ribozyme, indicating that the two helices bounding the internal loop are closer than was previously assumed. This arrangement rationalizes the observed ability of hairpin ribozymes with a circularized substrate-binding strand to cleave a circular substrate, and provides essential information concerning the organization of the substrate in the active conformation. The internal geometry of the substrate-binding strand places G8 of the substrate-binding strand near the cleavage site, which has allowed us to predict the crucial role played by this nucleotide in the reaction chemistry.

Observations on the use of adjuvant radiation therapy in patients with stage I and II uterine sarcoma.

From November 1973 through July 1982, 225 women with Stage I or II uterine sarcoma were entered on a protocol which evaluated the use of doxorubicin in the adjuvant setting. Of these, 157 patients had a minimum follow-up of 2 years. Following complete surgical removal of all known clinical disease, consenting patients were randomized to receive either 60 mg/m2 of doxorubicin every 3 weeks for eight courses or no further therapy. The use of radiation therapy in this protocol was optional, and a review of protocol cases was undertaken to determine progression-free interval, survival rates, and site of first recurrence in the radiation therapy and no radiation therapy groups. In patients with Stage I or II leiomyosarcoma of the uterus, there was no difference in the progression-free interval, absolute two-year survival rate, or site of first recurrence in the two groups. There was no difference in the progression-free interval or absolute survival rates for cases with Stage I and II uterine mixed mesodermal sarcomas in the two treatment groups. However, those who received radiation therapy to the pelvis experienced a statistically significant reduction of recurrences within the radiation treatment field.

Immature teratoma of the ovary with a neural component ("solid" teratoma). A clinicopathologic study of 20 cases.

Twenty cases of immature teratoma of the ovary with a neural component are analyzed. A plea is made for use of the nomenclature adopted from the new World Health Organization classification of ovarian tumors, the past confusion over terminology and histogenesis of this rare tumor is discussed. All the primary tumors in the present series contained at least some immature tissues (predominantly of neural origin) and were thus graded from 1 to 3 according to the criteria of Thurlbeck and Scully. No grade 0 tumors ("benign solid teratomas") were identified. We believe that thorough sectioning almost always insures the identification of immature elements. The prognosis was closely related to the histologic grade, but correlated poorly withthe clinical stage, the latter being influenced by the common finding (25 per cent of the cases in this series) of peritoneal implants composed exclusively of mature glial tissue, which is associated with a benign clinical evolution. This phenomenon of maturation or differentiation appears to be the rule rather than the exception in this tumor, since implants are usually of better or equal differentiation when compared with their primary tumors and older patients tend to have lower grade tumors than younger patients. Since the majority of patients with this tumor are young, primary surgical therapy should be conservative, unilateral salpingooophorectomy often being sufficient. Spontaneous or operative rupture of the tumor capsule carries an increased risk of subsequent dissemination. We have noted impressive clinical responses in patients with disseminated tumors of a high histologic grade after treatment with triple chemotherapy (vincristine, actinomycin D, and cyclophosphamide) but do not recommend adjuvant therapy in patients with only grade 0 implants.

Primary carcinoma of the fallopian tube.

The present report of 16 new cases of fallopian tube carcinoma also includes 2 new cases of adenoacanthoma, an exceedingly rare tumor. The histologic evaluation of tubal carcinoma is discussed. A meticulous search at surgery for occult disease is urged, because penetration of the tubal serosa seems to be the most important determinant of prognosis. Suggestions are made for adjunctive therapy, although the authors believe the time has come for a multicentered attempt to evaluate treatment protocols randomly.

Results of second-look laparotomy in patients with early-stage ovarian carcinoma.

One hundred twelve patients with early (FIGO stage I and II) ovarian carcinoma had a second-look laparotomy performed after comprehensive surgical staging and randomization into clinical protocols. Of the 95 patients who were asymptomatic before second-look laparotomy, only 5% had positive findings. In contrast, 53% of the 17 patients with findings that suggested recurrence or bowel obstruction had disease at second-look laparotomy. Overall, only 13% of the entire group of 112 patients had recurrent disease at second-look laparotomy. Asymptomatic patients with early ovarian carcinoma who have undergone careful initial surgical staging followed by appropriate adjuvant therapy can be spared a routine second-look operation.

Human papillomavirus deoxyribonucleic acid in adenocarcinoma and adenosquamous carcinoma of the uterine cervix.

This report describes the detection of human papillomavirus type 16 or 18 deoxyribonucleic acid (DNA) in nine of 15 invasive tumors of the cervix, including three squamous carcinomas, four adenosquamous carcinomas, one glassy cell carcinoma, and one adenocarcinoma. The viral DNA was identified by Southern blotting and DNA hybridization. Human papillomaviruses may play an etiologic role in the development of at least some adenocarcinomas and adenosquamous carcinomas as well as most squamous tumors of the cervix.

Weekly intramuscular methotrexate for nonmetastatic gestational trophoblastic disease.

Patients with nonmetastatic gestational trophoblastic disease were entered into this Gynecologic Oncology Group study to determine the efficacy, toxicity, and cost-effectiveness of weekly intramuscular (IM) methotrexate. Treatment was initiated with 30 mg/m2 of weekly IM methotrexate. If no major toxicity was encountered, the weekly dose was escalated 5 mg/m2 at three-week intervals until a maximum dose of 50 mg/m2 each week was achieved. Complete response was defined as three normal beta-hCG values measured on consecutive weeks. Fifty-one of 63 evaluable patients (81%) had a complete response to weekly IM methotrexate. Duration of therapy ranged from three to 19 weeks, with a median of seven. No major toxicity occurred. Thirteen patients experienced leukopenia at a median of 3300/microL, with a range of 2300-3900. Three patients had platelet nadirs of 66,000, 127,000, and 135,000/microL. Eleven patients with weekly IM methotrexate failure had a complete response after one to eight courses of dactinomycin administered 0.5 mg/m2 intravenously daily for five days; one refused therapy after three courses. Weekly IM methotrexate for nonmetastatic gestational trophoblastic disease is efficacious, minimally toxic, and cost-effective.

Management of immature teratoma of the ovary in children by conservative resection and chemotherapy.

Six patients with immature teratoma of the ovary were treated with surgery and chemotherapy. Surgical management consisted of unilateral salpingo-oophorectomy, biopsy and conservation of the contralateral ovary, and biopsy of peritoneal implants. Triple-agent chemotherapy with vincristine, actinomycin D, and cyclophosphamide was given to four patients and appeared to be beneficial. Radiation therapy was not employed. Local resection of teratomatous recurrences was frequently necessary. Thorough sampling of this tumor is mandatory for establishment of an exact pathologic diagnosis. All six patients are surviving in good health at 1-8-yr follow-up. The prognosis of immature teratoma in the child or adolescent appears more favorable than previously appreciated.

[The focus of discipline in nursing: clarification with ontologic basis]. / Le centre d'intérêt de la discipline infirmière: une clarification à l'aide des bases ontologiques.

The discipline of nursing is enhanced by the contributions of theoricians, researchers and practitioners in nursing who created ways that promote the knowledge development of nursing. The contribution of ontology allows for the clarification of the nature of reality from which stem the visions about phenomena to be studied. In nursing sciences, these visions are embedded in two different paradigms that influence the nature of the focus of the discipline as well. Some statements about the focus of the discipline are analysed and rules allowing for the choice of a coherent heuristic mode are set forth according to the chosen paradigm. The coexistence of paradigms deserves the respect of the different visions and the engagement to evaluate the theories of the discipline in relation with the values grounding our service to the society.

[Perception of autonomy in the elderly who live with a family member]. / L'expérience d'autonomie de la personne âgée qui vit avec un membre de sa famille.

In gerontological research and practice, autonomy is a phenomenon of central interest. Numerous researchers have considered autonomy as an elder's problem to be defined and resolved, and have studied the phenomenon from the psychological, sociological, or another discipline's perspective. The purpose of this phenomenological study was to describe the experience of autonomy as lived by 80 plus elders who share a household with a family member. Parse's human becoming theory oriented the nursing perspective to the study of autonomy toward the meanings of autonomy given by older persons within the rhythmicity of interpersonal relationships. The analysis of data for four women participants revealed the phenomenon essential themes as being able, still being someone, and chosen beyond changes. These themes are linked to the principle of cotranscendence from the human becoming theory: being able reveals the dynamic potential of each participant who, through their relationships, creates an original way of being still someone, and of choosing beyond life changes. Implications for nursing practice are discussed.