On-line separation of macromolecules by membrane filtration with cryogelation. 1980.
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Hemofiltration↗
Biomedical subjects
L Calabrese
Publications and source records attributed to L Calabrese.
Is there a role for sentinel node biopsy in early N0 tongue tumors?
BACKGROUND: Detecting metastases to the cervical lymph nodes is the main problem in the management of squamous cell carcinoma of the tongue. We investigated the ability of sentinel node (SN) biopsy to predict neck status in 11 patients with lateral T1-T2, N0, and M0 squamous cell carcinoma of the tongue who underwent ipsilateral neck dissection 30 to 40 days after primary surgery. METHODS: In 5 patients, technetium 99m-labeled particles were injected close to the operation scar on the day before neck dissection, and the labeled neck nodes were revealed by lymphoscintigraphy. The next 6 patients underwent lymphoscintigraphy both before surgery and before neck dissection. During neck dissection, the ipsilateral SNs were identified by using a hand-held probe and removed separately. RESULTS: Three patients (27%) had metastatic neck nodes. In all cases, labeled nodes were revealed by scintigraphy. Ipsilateral SNs were removed from 8 patients and correctly predicted the state of the neck (6 negatives and 2 positives). Lymphoscintigraphy before and after surgery revealed that drainage was modified after surgery in 5 of 6 patients; the pre-surgery drainage pattern varied markedly among the 5 pN0 patients. CONCLUSIONS: The technique allows easy and safe identification of SNs and shows promise in guiding selective neck dissection. Surgery on the primary tumor often modifies lymphatic drainage, so that SN biopsy may only be useful if the primary operation and neck dissection are performed at the same time.
Adult↗
Release of highly active Fet3 from membranes of the yeast Pichia pastoris by limited proteolysis.
A soluble derivative of Fet3 has been obtained from the methylotrophic yeast Pichia pastoris by limited proteolysis of membrane suspensions with trypsin. The soluble protein and the membrane-bound parent Fet3 have been purified to apparent homogeneity. Soluble Fet3 had molecular mass 100 kDa, while the full-length protein had molecular mass 110 kDa, in line with the expected decrease for cleavage and loss of a single transmembrane helix and a small cytoplasmic domain. The optical and EPR spectra of Fet3 were typical of the multicopper oxidases, indicating the presence of one type 1 blue copper site and a type 2/type 3 copper trinuclear cluster. V(max) values for iron oxidation by P. pastoris Fet3 were obtained similar to human ceruloplasmin and much higher than those reported for Saccharomyces cerevisiae Fet3.
Amino Acid Sequence↗
Investigation of the anomalous spectroscopic features of the copper sites in chicken ceruloplasmin: comparison to human ceruloplasmin.
Chicken ceruloplasmin has been previously reported to display a number of key differences relative to human ceruloplasmin: a lower copper content and a lack of a type 2 copper signal by electron paramagnetic resonance (EPR) spectroscopy. We have studied the copper sites of chicken ceruloplasmin in order to probe the origin of these differences, focusing on two forms of the enzyme: "resting" (as isolated by a fast, one-step procedure) and "peroxide-oxidized". From X-ray absorption, EPR, and UV/visible absorption spectroscopies, we have shown that all of the copper sites are oxidized in peroxide-oxidized chicken ceruloplasmin and that none of the type 1 copper sites display the EPR features typical for type 1 copper sites that lack an axial methionine. In the resting form, the type 2 copper center is reduced. Upon oxidation, it does not appear in the EPR spectrum at 77 K, but it can be observed by using magnetic susceptibility, EPR at approximately 8 K, and magnetic circular dichroism spectroscopy. It displays unusually fast relaxation, indicative of coupling with the adjacent type 3 copper pair of the trinuclear copper cluster. From reductive titrations, we have found that the reduction potential of the type 2 center is higher than those of the other copper sites, thus explaining why it is reduced in the resting form. These results provide new insight into the nature of the additional type 1 copper sites and the redox distribution among copper sites in the different ceruloplasmins relative to other multicopper oxidases.
Animals↗
Inhibition of endothelial nitric-oxide synthase by ceruloplasmin.
The plasma copper protein ceruloplasmin (CP) was found to inhibit endothelial nitric-oxide synthase activation in cultured endothelial cells, in line with previous evidence showing that the endothelium-dependent vasorelaxation of the aorta is impaired by physiological concentrations of ceruloplasmin. The data presented here indicate a direct relationship between the extent of inhibition of agonist-triggered endothelial nitric oxide synthase activation and CP-induced enrichment of the copper content of endothelial cells. Copper discharged by CP was mainly localized in the soluble fraction of cells. The subcellular distribution of the metal seems to be of relevance to the inhibitory effect of CP, because it was mimicked by copper chelates, like copper-histidine, able to selectively enrich the cytosolic fraction of cells, but not by copper salts, which preferentially located the metal to the particulate fraction.
Animals↗
Structure/function relationships in ceruloplasmin.
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Animals↗
On the lability and functional significance of the type 1 copper pool in ceruloplasmin.
The possibility that ceruloplasmin (CP) functions as a copper transferase has fueled a continuing interest in studies of the copper release process. The principal goal of the current investigation has been to identify the most labile copper centers in sheep protein. In fact, subjecting the enzyme to a slow flux of cyanide at pH 5.2 under nitrogen in the presence of ascorbate and a phenanthroline ligand produces partially demetalated forms of the protein. By standard chromatographic techniques it is possible to isolate protein with a Cu/CP ratio of approximately 4 or approximately 5 as opposed to the native protein which has Cu/CP = 5.8. In contrast to other blue oxidases, analysis suggests that CP preferentially loses its type 1 coppers under these conditions. Thus, the spectroscopic signals from the type 1 centers exhibit a loss of intensity while the EPR signal of the type 2 copper becomes stronger. Furthermore, the Cu/CP approximately 4 and Cu/ CP approximately 5 components retain about 50% of the activity of the native protein, consistent with an intact type 2/type 3 cluster. All three type 1 copper sites appear to suffer copper loss. Reconstitution with a copper(I) reagent restores the spectroscopic properties of the native protein and 90% of the original activity. The results suggest a possible functional significance for the presence of three type 1 coppers in CP. By employing a pool of redox-active but relatively labile type 1 copper centers, the enzyme can serve as a copper donor, if necessary, without completely sacrificing its oxidase activity.
Animals↗
Cervico-thoracic tumors resection through transmanubrial osteomuscular sparing approach.
Twelve patients with cervico-thoracic tumors underwent transmanubrial approach during a 1-year period. All but two patients with NSCLC (n = 8), had double approaches. Three cases with cervical esophageal cancer underwent TMA and laparotomy. The last patient underwent TMA for cervical fibrosarcoma. One patient underwent subclavian artery resection, while another one resection of the left brachicephalic vein with graft replacement. Two cases, in the esophageal cancer group, had laryngeal nerve palsy requiring temporary tracheostomy. TMA affords an excellent exposure of the thoracic in/outlet allowing extended resection. Sparing the main osteo-muscular structures, it respects shoulder mobility of the scapular girdle, thus avoiding deformities due to clavicle resection.
Adult↗
Surfing prognostic factors in head and neck cancer at the millennium.
The ability to reliably predict cancer outcome could tailor therapy to the aggressiveness of the tumour to achieve the best results in terms of loco-regional control, overall survival and quality of life. Retrospective and prospective clinical trials involving large series of patients have validated some predictive clinical and pathological factors, whereas the utility of many other prognostic factors has not been established. This has led to some confusion in clinical practice. In order to clarify the significance, role and cost of these prognostic factors we carried out a Medline search of all papers published between 1993 and 1998 concerning the reliability and cost of markers with prognostic significance, in head and neck squamous cell carcinoma, and assessed the results according to a number of criteria relating to reliability and cost. Regarding reliability we classified prognostic factors into: (1) those with a proven significance based on the fact that they were unanimously reported as having an independent statistical correlation with outcome and prognosis; and (2) those for which results were not unanimous, and which significance is still controversial. Cost analysis showed a substantial difference between validated tests which are of low cost and experimental tests which are expensive. Based on these data regarding both the reliability and cost of each prognostic factor, we propose guidelines for their use in clinical practice in the year 2000.
Biomarkers, Tumor↗
The multifunctional oxidase activity of ceruloplasmin as revealed by anion binding studies.
The effect of multiple binding of azide, N3-, on the structural and functional properties of ceruloplasmin (CP) has been reinvestigated by means of both spectroscopic and enzymatic techniques. High affinity binding of the anion to human CP resulted in a dramatic increase of the absorbance at 610 nm and in a concomitant decrease of the optical density at 330 nm. The oxidase activity toward Fe(II) was essentially unaffected, while turnover parameters versus nonferrous substrates dramatically changed, with an approximately 100-fold enhancement of the kcat/Km parameter. Chloride at physiological concentration proved to behave very similarly to N3- bound with high affinity, in that it not only induced the spectroscopic changes previously interpreted in terms of an intramolecular electron transfer from reduced type 1 to type 3 copper ions [Musci, G., Bonaccorsi di Patti, M.C. & Calabrese, L. (1995) J. Protein Chem. 14, 611-617], but it also enhanced some 60-fold the kcat/Km value. A different behavior was observed with chicken CP, where a decrease at 330 nm occurred without a concomitant modification at 603 nm. The chicken enzyme was less sensitive also in terms of enzymatic activity, which was nearly unchanged in the presence of either high affinity N3- or Cl-. At higher N3- concentrations, optical changes of both human and chicken CP were mainly focussed on the appearance of ligand-to-metal charge transfer bands below 500 nm, and the anion behaved as an inhibitor of the oxidase activity versus Fe(II) as well as noniron substrates. The well known bleaching of the blue chromophore could be observed, at neutral pH, only at very high N3-/CP ratios. The data presented in this paper are consistent with a mechanism of structural and functional modulation of CP by anions, that would be able to dictate the substrate specificity of the cuproprotein, and suggest the possibility that CP may act in vivo as a multifunctional oxidase.
Animals↗
Homology modeling of the multicopper oxidase Fet3 gives new insights in the mechanism of iron transport in yeast.
Fet3, the multicopper oxidase of yeast, oxidizes extracellular ferrous iron which is then transported into the cell through the permease Ftr1. A three-dimensional model structure of Fet3 has been derived by homology modeling. Fet3 consists of three cupredoxin domains joined by a trinuclear copper cluster which is connected to the blue copper site located in the third domain. Close to this site, which is the primary electron acceptor from the substrate, residues for a potential iron binding site could be identified. The surface disposition of negatively charged residues suggests that Fet3 can translocate Fe(3+) to the permease Ftr1 through a pathway under electrostatic guidance.
Amino Acid Sequence↗
Cancer screening in otorhinolaryngology.
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France↗
Detecting alcohol use disorders in the severely mentally ill.
The frequent co-occurrence of alcoholism with serious mental illnesses ("dual diagnosis") necessitates that clinicians are able to recognize its presence in people with disabling mental illnesses. This study demonstrates that professionals often miss the diagnosis, but that their ability to detect alcoholism can be greatly enhanced by the use of a simple screening tool. Members of an urban psychosocial rehabilitation program who received psychiatric treatment in an affiliated outpatient clinic were interviewed after their clinic therapists and rehabilitation counselors had been asked questions pertaining to their general health and substance use. The members were interviewed with two screening tests, the CAGE and the SMAST, and a clinical DSM-III-R diagnosis of alcohol use disorder was established. Both the SMAST and CAGE had good sensitivity and the addition of a screener enhanced the clinicians' ability to detect alcohol use disorders.
Adult↗
Thalidomide revisited: pharmacology and clinical applications.
Thalidomide is attracting new interest. Since the discovery of its remarkable efficacy in erythema nodosum leprosum, the drug has been used successfully in a variety of dermatologic and other diseases whose apparent common thread is immune dysregulation. Meanwhile, immunomodulatory and anti-inflammatory activities of thalidomide, particularly its inhibition of tumour necrosis factor alpha (TNF-alpha), have been identified and elucidated. The drug has also been found to inhibit angiogenesis. Recent clinical trials have shown thalidomide effective in graft-versus-host disease, Behçet's syndrome and aphthous ulcers and wasting associated with HIV infection. Provocative findings in other diseases, including primary HIV infection, HIV-associated diarrhoea, inflammatory bowel disease, cancer and sepsis, have suggested additional clinical applications. Use of thalidomide in women capable of childbearing is controversial. However, guidelines have emerged for prevention of teratogenicity and peripheral neuropathy, the drug's other major adverse effect. With appropriate safeguards, thalidomide may hold benefit for patients with a broad variety of disorders in which existing treatments are inadequate. Its current use may represent only a small part of its therapeutic potential.
Journal Article↗
[Thrombosis of the portal vein].
The portal venous thrombosis is an infrequent disease that accounts from 0.25 to 1%. The etiopathogenesis is unknown in about one half of cases. Sometimes the thrombosis of mesenterico-portal venous axis is a complication following splenectomy, especially when the operation is performed for hematologic disease. The authors report a clinical case of chronic portal venous thrombosis widespread to superior mesenteric and splenic vein, in man 38 years old after splenectomy, in pediatric age, manifesting with gastrointestinal bleeding due to rupture of esophagogastric varices. On the basis of literature, the following were taken into consideration the incidence, the epidemiology, the aetiopathogenesis, the clinical characteristics, the diagnosis as well as the therapy of portal venous thrombosis.
Adult↗
[Primary neoplasms of the jejunum-ileum. The clinico-diagnostic and surgical therapy considerations: the clinical cases and a retrospective study of our experience].
Primary tumors of the jejunum-ileum are rare and constitute about 2% of gastrointestinal neoplasms. The first clinically reported small bowel tumor was a jejunal carcinoma described in 1824 by Sorlin. The authors reviewed our surgical experience of 9 patients treated at the Department of General Surgery of the "E. Franchini" Hospital of Montecchio Emilia (Re) during a 13-years period from 1984 to 1997. On the basis of literature on the topic, the following are taken into consideration, the history, the incidence, the epidemiology, the aetiopathogenesis, the clinical characteristics, the diagnostic, the surgical therapy of these tumors. The subjects included 6 males and 3 females. The average age of the patients was 66 years, with a male predominance ratio of 2:1. Of the seven primary malignant tumors observed, two patients had adenocarcinomas, two had leiomyosarcomas, two had lymphomas and one carcinoid. The benign tumors were respectively leiomyomas and small intestinal stromal tumor. The most common signs and symptoms were abdominal pain and obstruction of the intestine. Preoperative diagnosis was established in 4 of these patients only by roentgenographic examinations, in 2 by ultrasound scan, in 2 by ultrasound scan and computed tomography, in 1 by endoscopic examination. All the 9 tumors were resected: in 7 patients (77.7%) the resection were considered as curative and in 2 patients (22.3%) palliative. All operated patients were staged by the TNM-classification using pathological and surgical reports. The staging of the disease was the following: 2 patients with stage 1 (T2N0M0), 2 patients with stage II (T4N0M0), 3 patients with stage III (1 with T3N1M0 and 2 with T4N1M0), 2 patients with stage IV (T4N1M1). Survival correlated with the different TNM stage: the median survival time was 60 months for stage I, 60.5 months for stage II, 40 months for stage III and 18 months for stage IV.
Adult↗
[Noninvasive breast carcinomas: anatomicopathological, diagnostic and therapeutic findings].
The carcinoma in situ of the breast is a noninvasive variant of breast cancer which has an favorable prognosis with appropriate management. The widespread use of mammography has contributed to its increased rate of diagnosis. Special attention to the problem of in situ carcinoma is justified by the increasing frequency of its recognition and the controversy surrounding the proper treatment. Carcinoma in situ (CIS) of the breast can be divided in two categories, depending on where it arises: ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). The two histologic kinds of this cancer have distinct pathologic and biologic characteristics, with different therapeutic implication. The author, on the basis of literature on the topic, reviews present studies of DCIS and LCIS with a particular care for the pathology, the diagnostic approaches and the current treatment of these tumors.
Biopsy, Needle↗
Investigation of the integration process of dental implants by means of a numerical analysis of dynamic response.
OBJECTIVES: The aim of this work was to present a preliminary numerical analysis of the integration process of dental implants using a finite element simulation of the dynamic response following impulse excitation. Assessment of the osseointegration process has been previously examined using a numerical approach by calculating the natural frequency of a cantilever attached to the implant. The methodology adopted in this work allows a direct measurement of the implant response following impulse loading and avoids the addition of a bulky cantilever set-up. METHODS: The geometric configuration was obtained by averaging the coordinate data from tomographic scans of 14 mandibles. The materials properties were approximated from experimental analysis performed on trabecular and cortical bone tissue. A load was applied to the top of the implant in one direction resulting in an initial displacement. The implant was then freed and allowed to vibrate over approximately 10 cycles. Three fixity conditions were assumed by changing the properties of the surrounding bone ranging from full integration to a poorly integrated implant typical of the situation during bone healing following surgery. The results of the three fixity conditions were compared by calculating the fundamental displacement amplitudes and frequencies of the vibrating impact. RESULTS: The calculated results indicated that the implant vibrated at a predominant frequency when partially integrated with a displacement principally in the direction of the applied impulse. However, when the implant was fully integrated a more complex vibration pattern ensued, suggesting the superposition of two or more fundamentals. SIGNIFICANCE: Attention has been paid to the formulation of the numerical model for validation purposes as well as a reliable reference for the optimum interpretation of the experimental data. In this way it was possible to establish a simulation procedure to investigate the response of the tissues surrounding the implant and their properties at different stages of healing. It should be pointed out that the numerical procedures represented a valid preliminary approach to the problem and were capable of indicating a guide to the optimum design of the experimental apparatus for measurement of displacement and frequency in vivo.
Alveolar Process↗