DNA sequences acting as binding sites for NM23/NDPK proteins in melanoma M14 cells

We isolated and analyzed by chromatin immunoprecipitation (ChIP) in viable M14 cells DNA sequences bound to the antimetastatic protein nucleoside diphosphate kinase (NM23/NDPK) to shed some light on the nuclear functions of this protein and on the mechanism by which it acts in development and cancer. We assessed the presence of selected sequences from promoters of platelet-derived growth factor A (PDGF-A), c-myc, myeloperoxidase (MPO), CD11b, p53, WT1, CCR5, ING1, and NM23-H1 genes in the cross-linked complexes. Quantitative PCR (Q-PCR) showed a substantial enrichment of the correlated oncosuppressor genes p53, WT1, ING1, and NM23-H1 in the immunoprecipitated (IP) DNA. This suggests that NM23/NDPK binding is involved in the transcription regulation of these genes. These results reveal new interactions that should help us to disclose the antimetastatic mechanism of NM23.

Quaternary structure of Dictyostelium discoideum nucleoside diphosphate kinase counteracts the tendency of monomers to form a molten globule

Multimeric enzymes that lose their quaternary structure often cease to be catalytically competent. In these cases, conformational stability depends on contacts between subunits, and minor mutations affecting the surface of the monomers may affect overall stability. This effect may be sensitive to pH, temperature, or solvent composition. We investigated the role of oligomeric structure in protein stability by heat and chemical denaturation of hexameric nucleoside diphosphate kinase from Dictyostelium discoideum and its P105G mutant over a wide range of pH. The wild-type enzyme has been reported to unfold without prior dissociation into monomers, whereas monomer unfolding follows dissociation for the P105G mutant (Giartosio et al. (1996) J. Biol. Chem. 271, 17845-51). We show here that these features are also preserved at alkaline pH, with the wild-type enzyme always hexameric at room temperature whereas the mutant dissociates into monomers at pH >or=10. In acidic conditions (pH <or=6), even in the absence of denaturant, the predominant species for both proteins is an intermediate monomeric form with the characteristics of a molten globule: disordered tertiary native structure but preserved secondary structure. Monomers therefore seem to have a low intrinsic stability, which is overcome by the conformational organization in the oligomeric structure.

In vivo cross-linking of nm23/nucleoside diphosphate kinase to the PDGF-A gene promoter

Human isoforms A and B of nm23/nucleoside diphosphate (NDP) kinase, functionally important in development and cancer, have been reported to bind to DNA, and in particular isoform A to the PDGF-A promoter and isoform B to the c-myc promoter and to telomeric repeats. However, no direct proof of the binding in vivo has yet been obtained. To demonstrate this interaction, human erythroleukemic K562 cells were incubated with two different cross-linking reagents, formaldehyde or cis-diammine dichloro platinum H. The DNA-protein covalent complexes were isolated and analyzed by Western blotting. The positive immunochemical staining showed that in both conditions NDP kinase isoforms A and B were efficiently cross-linked to DNA in vivo. NDP kinase-linked DNA fragments obtained by immunoprecipitation, subjected to hybridization with different probes, showed a definite enrichment in the nuclease-hypersensitive silencer element of the PDGF-A promoter. No conclusive evidence was found by this technique of preferential hybridization with a nuclease-hypersensitive element of the c-myc promoter and with the telomeric TTAGGG repeats. The immunoprecipitated NDP kinase-DNA complexes are a promising material for the detection of other specific DNA sequences interacting with NDP kinase.

Binding of nucleotides to nucleoside diphosphate kinase: a calorimetric study

The source of affinity for substrates of human nucleoside diphosphate (NDP) kinases is particularly important in that its knowledge could be used to design more effective antiviral nucleoside drugs (e.g., AZT). We carried out a microcalorimetric study of the binding of enzymes from two organisms to various nucleotides. Isothermal titration calorimetry has been used to characterize the binding in terms of Delta G degrees, Delta H degrees and Delta S degrees. Thermodynamic parameters of the interaction of ADP with the hexameric NDP kinase from Dictyostelium discoideum and with the tetrameric enzyme from Myxococcus xanthus, at 20 degrees C, were similar and, in both cases, binding was enthalpy-driven. The interactions of ADP, 2'deoxyADP, GDP, and IDP with the eukaryotic enzyme differed in enthalpic and entropic terms, whereas the Delta G degrees values obtained were similar due to enthalpy--entropy compensation. The binding of the enzyme to nonphysiological nucleotides, such as AMP--PNP, 3'deoxyADP, and 3'-deoxy-3'-amino-ADP, appears to differ in several respects. Crystallography of the protein bound to 3'-deoxy-3'-amino-ADP showed that the drug was in a distorted position, and was unable to interact correctly with active site side chains. The interaction of pyrimidine nucleoside diphosphates with the hexameric enzyme is characterized by a lower affinity than that with purine nucleotides. Titration showed the stoichiometry of the interaction to be abnormal, with 9--12 binding sites/hexamer. The presence of supplementary binding sites might have physiological implications.

Spontaneous cerebellar hemorrhage: clinical remarks on 50 cases

BACKGROUND

Only during the past 10 years have spontaneous cerebellar hemorrhages became a well-defined nosological entity. The surgical indication remains debatable. Our primary objective in this study was to set the criteria for undertaking surgery by determining the critical diameter of the hematoma and considering the patients' neurological status (Glasgow Coma Scale).

METHODS

During the 8-year period 1990 through 1997 a series of 50 consecutive patients with spontaneous cerebellar hemorrhage were admitted to the Emergency Neurosurgery Unit, University of Rome "La Sapienza" (Italy). On admission all patients underwent a standard neurological examination, (Glasgow Coma Scale) and a computed tomographic scan. The diameter and the site of the hematoma, a coexisting tight posterior fossa, and the presence of hypertensive hydrocephalus were the criteria, in association with the patients' neurological status, used as indications for surgery.

RESULTS

Operative mortality was nil; and perioperative mortality eight patients (16%, increasing to 24% including the four patients who were deeply comatose on admission). Most patients who died (seven of eight) had two or more general medical risk factors (arterial hypertension and diabetes mellitus; arterial hypertension and liver disease; or liver disease and hematological disorders).

CONCLUSION

In patients presenting with spontaneous cerebellar hemorrhage the essential criteria indicating surgery are a hematoma 40 mm x 30 mm on CT imaging in the cerebellar hemisphere or 35 mm x 25 mm on CT imaging in the vermis, the presence of a tight posterior fossa (critical size reduced by 10 mm), and a Glasgow Coma Score less than 13.

Medulloblastoma in late adults. Case report and critical review of the literature

BACKGROUND

Medulloblastoma in late adults (older than 65 years) is an exceptional occurrence; in fact only 8 cases are reported with complete clinical notes in the literature.

METHODS

The authors describe a case of medulloblastoma occurring in a 68-year-old man and analyzed cases reported in the literature.

RESULTS

The overall average age of the patients was 72.8 years (range 67-88 years), and the male prevalence of this tumour (70% of cases) seems to be unrelated to age. There is a lateral predominance in late adults (77.7% of cases). Seven patients underwent operation and subsequently these patients underwent a course of radiation therapy. Only two patient was treated with postoperative chemotherapy. Median survival for seven patients treated was 43.2 months (range 23-96 months).

CONCLUSIONS

It is interesting to note that: 1) histological analysis revealed a classic type medulloblastoma (88.8% of cases) similar to the children: 2) site of the tumor is lateral similar to the adults (77.7% of cases).

DNA-protein cross-linking in nuclei of immature and mature chicken erythrocytes

DNA-protein cross-linkages were formed in isolated nuclei from immature and mature chicken erythrocytes by reaction with cis-diammine dichloroplatinum. On the basis of electrophoretic behaviour, the most abundant proteins involved in the cross-linking appeared to be present also in preparations of nuclear matrix. The maturation of the erythrocyte, which is accompanied by transcriptional inactivation, leads to a decrease in the amount of DNA-interacting proteins, to a loss of proteins capable of a specific recognition of DNA sequences and, unexpectedly, to the appearence of some new DNA-protein interactions. At least three cross-linked proteins were found predominantly or exclusively in nuclei of immature cells, and three others in those of mature ones. The three DNA-bound proteins, typical of mature erythrocytes, were not found among the components of a high-salt preparation of nuclear matrix. The results obtained suggest that, in addition to the well-known histone H5 and MENT protein, these newly identified DNA-bound proteins contribute to the formation of the condensed, inactive chromatin characteristic of mature erythrocyte.

An asymptomatic hypertrophic pacchionian granulation simulating osteolytic lesion of the calvaria

Osteolytic lesions can be seen in various diseases. We present a rare case of symptomatic hypertrophic pacchionian granulation mimicking bone tumor in the calvaria. A 50-year-old woman suffered from a previous VII cranial nerve peripheral paresis accompanied by headache. A plain radiograph revealed a punched-out paramedial occipital lesion. Precontrast-enhanced computed tomographic scans demonstrated a hypodense mass, with a defect of both tables of the left occipital bone. Magnetic resonance imaging (MRI) demonstrated a hypointense mass on the T1-weighted image and isointense to cerebrospinal fluid on the T2-weighted image, with capsule-like contrast enhancement by gadolinium. A biopsy was performed. Histologically, hypertrophic pacchionian granulation was diagnosed. The patient has had no growth for 2 years. This case suggests the need to include hypertrophic pacchionian granulation in the differential diagnosis of punched-out lesions.

Cross-linked telomere-protein complexes from chicken erythrocyte nuclei: isolation by a new procedure

DNA-protein cross-linkages were produced in intact nuclei of chicken erythrocytes by the action of cis-diammine dichloroplatinum. The telomeric DNA-protein cross-linked complexes were then isolated by hybridization with a biotinylated oligonucleotide and selective binding on immobilized streptavidin. Two main nonhistone proteins were present in the purified complexes, migrating in SDS-gel electrophoresis with apparent molecular masses of 66 and 58 kDa, respectively. Although the identity of these two proteins is still unknown, it is significant that two proteins with similar electrophoretic behavior have been described as constituents of the human telomeric complexes. This procedure could also be applied to the isolation of DNA-protein cross-linked complexes containing any chosen DNA sequence.

Cerebral metastasis from ovarian carcinoma. Some observations about treatment

Systemic metastases from ovarian carcinoma are frequent, but they rarely affect the central nervous system. The treatment of this type of metastases in not clear. Two cases of solitary cerebral metastasis from ovarian carcinoma are reported. Two patients, submitted to therapeutic protocol established for ovarian carcinoma, presented after 17 and 25 months respectively the appearance of symptoms from brain solitary metastasis without other metastases. They underwent surgery, radiotherapy and chemotherapy for solitary cerebral metastasis. Treatment of the brain lesion resulted in KPS improvement (KPS = 90) and survival was 16 and 30 months, respectively. From the 2 cases presented and the review of the literature, it appears that a better outcome may be obtained by a combined treatment of metastases, including surgery, radiotherapy and chemotherapy.

Solitary plasmacytoma of the calvarium: a review of clinical and prognostic features

Primary craniocerebral plasmacytomas are uncommon they represent only 0.7% of all plasmacytomas. We report one case of solitary plasmacytoma of the skull and discuss the clinical features and prognosis of this tumor. There seems to be no difference in prognosis between plasmacytomas originating from the bone (osseous form) and those originating from the dura mater (non-osseous form). In these lesions, the risk of secondary multiple myeloma appears to be low.

Intraosseous schwannoma of the vault of the skull

Intraosseous schwannoma is a rare benign tumor of the bone with characteristic radiological and histological features. The most common sites of this tumor are mandible, sacrum, und vertebral bodies. Two cases, one of which is the first diagnosed with MRI, of this tumor in the vault of the skull are presented.

[Therapeutic considerations in solitary cerebral metastases from uterine carcinoma]

Brain metastases from endometrial carcinoma rarely involve the nervous system and are solitary in exceptional cases (< 1% of cases). Two cases of solitary cerebral metastasis from endometrial carcinoma are described. Two patients, submitted to the therapeutic protocol established for endometrial carcinoma, underwent surgery, radiotherapy and chemotherapy for solitary cerebral metastasis after at average interval of 18 months. Average survival was 46 months and death was due to progression of the systemic disease. An examination of our cases and those described in the literature has shown that, although these metastasis do not respond well to therapeutic treatment, a better outcome may be achieved by combined treatment consisting of surgery, radiotherapy and chemotherapy.

Metastatic spinal cord compression. Clinical remarks

BACKGROUND

Metastatic compression of the spinal cord is a frequent occurrence throughout the evolution of neoplastic disease. Possible clinical-diagnostic strategies and therapeutic management of this pathology are discussed in terms of survival and quality of life.

METHODS

The study includes 59 patients (40 males and 19 females, with an average age of 48.4 years) with metastatic spinal compression treated surgically in our centre (in some cases with stabilization of the spinal segment involved).

RESULTS

In 40 cases the localization of the primary tumor was known when the patient was admitted. The segment involved was the dorsal one in 41 cases. The most frequent type of tumor was pulmonary carcinoma in males and breast carcinoma in females. Average survival was 5.3 months. Treatment integrated by stabilization improved the quality of life in comparison to laminectomy alone. Survival was also influenced by the histological type and site of the primary tumor.

CONCLUSIONS

Surgical treatment not only prolongs survival but, above-all, guarantees a satisfactory quality of life.

Long-term survival in a patient with supratentorial glioblastoma: clinical considerations

Glioblastoma, a malignant tumor of neuroepithelial origin, is relatively uncommon in childhood, during which it accounts for 7%-9% of brain tumors. A few patients (about 3%) live more than 5 years. We report a 13-year-old girl who was admitted because one month earlier she had begun to present headache and diplopia. Brain computed tomography (CT) showed a right frontal tumor. At operation, complete excision of the visible tumor was performed. Histologic examination showed that the tumor was a glioblastoma multiforme. The patient underwent 52 Gy of external beam radiotherapy to the enhancing tumor mass plus 3-cm border, and chemotherapy with nitrosourea (BCNU). Fourteen years, 9 months later, the patient presents neither neurological deficits nor radiological relapse. We confirm that younger age, the one immutable prognostic factor, supports a particularly aggressive approach to the treatment of glioblastomas.

Desmoplastic fibroma of the skull. Case report and review of the literature

BACKGROUND AND PURPOSE

We present a rare case of desmoplastic fibroma of the skull. Desmoplastic fibroma is a distinctive and rare neoplasm of bone that histologically and biologically mimics desmoid soft tissue tumor. Only 6 cases have been reported in the skull and none of these was diagnosed by MRI.

CLINICAL PRESENTATION

A 64 year-old woman, operated on in June 1991 for left mastectomy due to a ductal adenocarcinoma and again in October 1994 for a left frontal metastatic adenocarcinoma, was admitted in our Department of Neurosurgery because a control cerebral MRI had detected a diploic lesion, isointense on T1-weighted images and hyperintense on T2, with moderate enhancement, localized in a right parietal site. Neurological examination was negative. The lesion was surgically removed and a cranioplasty was performed. Histological diagnosis was desmoplastic fibroma. Twelve months after treatment she has no neurological symptoms or signs of cerebral lesions (MRI) or systemic metastasis (total body CT).

CONCLUSION

In the literature the number of desmoplastic fibroma is too small and the follow-up period too short to permit any conclusions regarding the aggressiveness of the tumor.

Epithelioid schwannoma of the ulnar nerve. Some clinical observations

The authors describe one case of purely epithelioid schwannoma of the ulnar nerve and discuss the therapeutic management. A 44 year-old man was referred to us for a fusiform, movable mass in the left ulnar nerve and was removed by a wide en bloc excision. Intraoperative nerve action potentials were performed both prior to and following excision of the lesion. Histologically, the tumor was composed of round or polygonal cells arranged in necrotic clusters and anastomosing cords. There were areas of spindle cells. The epithelioid cells were round with abundant cytoplasm. Mitoses were frequent. S100 protein immunoreactivity was present diffusely in tumor cells (both nuclear and cytoplasmic), whereas cytokeratin, NSE, and anti-melanoma reactions gave negative results. After a 13 months, the patient's neurological conditions are excellent and there are no signs of either recurrence or metastasis.

[Epidermoid cyst of the cranial vault. Neuroradiological and therapeutic considerations]

AIM

Intradiploic epidermoid cyst is a slow-growing tumor affecting only rarely the cranial bones.

PATIENT

The authors describe a case of intradiploic epidermoid cyst of the cranial vault in which there was a predominantly intracranial extension. Roentgenographic and CT findings do not permit a differential diagnosis. Complete removal of the cyst and its capsule was accomplished, with complete recovery.

CONCLUSION

Total removal oft the tumor and its capsule is associated with a very good long-term prognosis without recurrences.

Sarcoma metastatic to the brain: a series of 15 cases

METHODS

We report on 15 patients surgically treated for intraparenchymal brain metastases from sarcoma, including six osteosarcomas, five leiomyosarcomas, two malignant fibrous histiocytomas, and two alveolar soft-part sarcomas (ASPS).

RESULT

Median survival after craniotomy was 9.3 months. Patients with a preoperative Karnofsky performance score of > 70 survived for 12.8 versus 5.3 months for those with a Karnofsky performance score < 70 (p=0.03). Patients with evidence of only lung metastases at the time of surgery (nine cases) survived 8.6 months, which was similar to the 10.4-month survival for patients with disease limited to the brain (p=0.1). The two patients with alveolar soft-part sarcomas are alive at 15 and 20 months after surgery.

CONCLUSION

We conclude that surgery is effective in treating selected patients with sarcoma metastatic to the brain and that patients with metastasis from ASPS may have a relatively good prognosis if they are surgically treated. The complete removal of all brain metastases and a Karnofsky performance score > 70 are associated with a favorable prognosis; the presence of concurrent lung metastases is not a contraindication to surgery.

Role of the dimeric structure in Cu,Zn superoxide dismutase. pH-dependent, reversible denaturation of the monomeric enzyme from Escherichia coli

To investigate the structural/functional role of the dimeric structure in Cu,Zn superoxide dismutases, we have studied the stability to a variety of agents of the Escherichia coli enzyme, the only monomeric variant of this class so far isolated. Differential scanning calorimetry of the native enzyme showed the presence of two well defined peaks identified as the metal free and holoprotein. Unlike dimeric Cu,Zn superoxide dismutases, the unfolding of the monomeric enzyme was found to be highly reversible, a behavior that may be explained by the absence of free cysteines and the highly polar nature of its molecular surface. The melting temperature of the E. coli enzyme was found to be pH-dependent with the holoenzyme transition centered at 66 degrees C at pH 7.8 and at 79.3 degrees C at pH 6.0. The active-site metals, which were easily displaced from the active site by EDTA, were found to enhance the thermal stability of the monomeric apoprotein but to a lower extent than in the dimeric enzymes from eukaryotic sources. Apo-superoxide dismutase from E. coli was shown to be nearly as stable as the bovine apoenzyme, whose holo form is much more stable and less sensitive to pH variations. The remarkable pH susceptibility of the E. coli enzyme structure was paralleled by the slow decrease in activity of the enzyme incubated at alkaline pH and by modification of the EPR spectrum at lower pH values than in the case of dimeric enzymes. Unlike eukaryotic Cu,Zn superoxide dismutases, the active-site structure of the E. coli enzyme was shown to be reversibly perturbed by urea. These observations suggest that the conformational stability of Cu,Zn superoxide dismutases is largely due to the intrinsic stability of the beta-barrel fold rather than to the dimeric structure and that pH sensitivity and weak metal binding of the E. coli enzyme are due to higher flexibility and accessibility to the solvent of its active-site region.

Intracerebral schwannoma. Case report

A case of intraparenchymal schwannoma is presented. A 61-year-old woman, with stigmata of von Recklinghausen's neurofibromatosis (NF-2), presented with a history of weakness of the right lower limb for 2 months. She was investigated by MR which showed a circular mass with a maximum diameter of 5 cm in the right parieto-occipital lobe. The tumor was removed in toto via a left parieto-occipital craniotomy. The patient was discharged two weeks after the operation and remains well now 2 years later. The clinical and neuroradiological findings of reported intraparenchymal schwannomas, including the case reported here, are discussed.

Benign neural sheath tumours of major nerves: characteristics in 119 surgical cases

Peripheral benign nerve sheath tumours are infrequent tumours and affect major nerve trunks. Some authors have indicated a high and prohibitive incidence of neurological injury in resection of these lesions. The authors describe their findings in a retrospective study comprising 119 patients with spontaneous benign nerve sheath tumours of the peripheral nervous system. Seventy-three patients had a schwannoma, 41 had neurofibroma and 5 had plexiform neurofibroma; 25 of the 119 patients suffered from neurofibromatosis. All schwannomas were excised completely and the outcome of patients was 41.0% improved, 6.8% worsened, 52.0% unchanged. Twenty-eight neurofibromas were excised completely and 13 subtotally; the outcome for patients was 19.5% improved, 19.5% worsened and 61% unchanged. All plexiform neurofibromas were removed subtotally and the outcome for patients was 20% improved and 80% unchanged. The best surgical results at average follow-up of 6 years were observed in the patients with schwannoma, the worst in those with plexiform neurofibroma. Our results demonstrated that it is often possible to remove schwannomas as well as neurofibromas with an acceptable risk of injury to the nerve.

Primary rhabdomyosarcoma of the brain: observations on a case with clinical and radiological evidence of cure

Cerebral rhabdomyosarcoma is a highly aggressive tumor with poor prognosis affecting children and, rarely, adults. The authors describe the case of a patient treated for primary fronto-parietal embryonal rhabdomyosarcoma with a long survival (30 months after surgery) and no clinical or radiological evidence of recurrence and discuss the chemotherapy applied in this case.

Long-term survival in patients with supratentorial glioblastoma

The authors report 11 patients with cerebral glioblastoma who lived at least 5 years after their initial diagnosis. There were 6 female and 5 male; the mean age was 39 years (range 24-55 years). All patients were treated surgically and postoperatively received whole-brain radiotherapy and chemotherapy. Five patients (45%) presented local recurrences after an average interval of 3.9 years from treatment. At average follow-up of 9 years (range 5-14 years), 7 patients (64%) were alive after an average interval of 8.1 years; 4 patients (36%) died from local relapse. Survival was influenced by patient age and, to a lesser degree, by treatment. A review of the literature, together with our own series, suggest that death from recurrence disease is unusual in glioblastoma patients who survive more than 5 years.

Severe head trauma. Review of the factors influencing the prognosis

A series of 72 severely head injured patients are reported, 24 (33%) with surgical intracranial hematomas. All patients were intensively cared for under the same therapeutic regime; intracranial pressure (ICP) was monitored and treated if increased. The series mortality was 39%. Uncontrollable increase of ICP (UI-ICP), always fatal, was observed in 18% of patients and in 13 of 28 deaths (46%); the incidence of UI-ICP among deaths was higher in patients less than in those more than 40 years old (55% vs 25%). Patients with UI-ICP were frequently deeply comatose and with arterial hypotension on admission; almost all died in the first days. Patients directly admitted from the scene with well staffed Life Flight Helicopter Emergency Care compared with those directly admitted from the scene with different type of ambulance service (paramedics, police, firemen and private) had a mortality rate significantly less (20% vs 54%) and an incidence of UI-ICP strongly lower both among patients (5% vs 29%) and among deaths (25% vs 54%). Thus in this small series intensive care after admission was not effective to obtain good results if patients had received poor preadmission emergency care. Review of the literature on main clinical predictors of outcome in severe head injury, have made possible some observations. Ischemic and intracranial hypertension brain lesions were generally present in patients killed by head trauma; while diffuse axonal injury, frequently responsible for vegetative, severe disability survival and late deaths, was observed only in 20-30% of postmortem examinations. Old age, poor neurological status and cardiocirculatory and respiratory disturbances prior to and upon admission positively worsened the outcome, while intracranial hematomas had a more variable predictive value. Intracranial hypertension was a definitively ominous predictor only if very high when the risk to be or become uncontrollable seems to be much elevated. UI-ICP, often fatal despite any aggressive therapy, was the single most frequent killer after severe head injury, responsible for about half of all deaths after admission. The different outcome among severe head injury series could be conceivably related to a different frequency of UI-ICP. Besides the severity of head injury and delay and mode of admission, we suggest that preadmission respiratory and cardiocirculatory and the quality of emergency medical system could strongly affect the incidence of uncontrollable increase of ICP in admitted patients and thus the mortality rate and favorable recovery of the series. The advanced preadmission emergency care service with intensive care after admission could significantly explain the better results often observed in severe head injury series.