Biomedical subjects
Publications and source records attributed to R Colombo.
We present the case of a 44-year old man, presenting with acute left flank pain and gross haematuria, affected by bilateral renal mass and massive para-aortic and mediastinic lymphadenopathy, highly suspicious for metastatic renal cancer.
The objective was to confirm the hypothesis that shortening reaction (ShoRe), normally occurring on forcibly shortening a muscle, is depressed or delayed in post-stroke patients. Eight post-stroke patients and ten age-matched normal subjects had a 50 degrees wrist extension or flexion induced by a torque-motor in the affected and the non-affected upper limb. Patients were instructed either not to intervene or to assist displacement (reaction-time condition, RT). Frequency of occurrence and latency of stretch reflex (SR) and ShoRe, and RTs were measured from the electromyograms (EMG) of wrist flexor (FCR) and extensor (ECR) muscles. SR had higher than normal frequency in both muscles. ShoRe disappeared in ECR on the affected side but had normal frequency in FCR of both sides. ShoRe latency was prolonged in FCR and ECR, in both affected and unaffected sides. RTs were prolonged in both FCR and ECR, in both affected and unaffected sides. Across all patients, RTs and ShoRe latencies in the FCR were correlated. Neither RTs nor ShoRe latencies were correlated to Ashworth score. RTs were inversely correlated to Medical Research Council scores. The decreased and delayed ShoRe in post-stroke patients supports a role for the cortico-spinal pathway in its production or modulation. Monitoring of ShoRe can give insight into the recovery of the descending control of spinal reflexes.
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BACKGROUND: Scabies is a very common skin infection in convicts. The SIMSPE Society (Società Italiana di Medicina e Sanità Penitenziaria) has organized and conducted a multicentre, randomized, comparative, parallel group, investigator-blinded trial to evaluate the efficacy and tolerability of synergized pyrethrins foam (PF) in comparison with benzyl benzoate (BB) lotion. METHODS: A total of 240 convicted patients, enrolled in eight National Jail Institutions, with a clinical diagnosis of scabies, were treated with PF (n = 120) for three consecutive days or BB (n = 120) for five consecutive days. Primary study endpoints were the clinical cure rate and the local tolerability. Secondary endpoints were clinical evolution of scabietic lesions and itching intensity. Study outcomes were assessed using appropriate semiquantitative scores at baseline and after 2 and 4 weeks. A second treatment cycle was applied if after 2 weeks the patient was not judged clinically cured. RESULTS: At week 2, a total of 75% (95% CI: 66-82%) and 71% (95% CI: 62-78%) of patients showed a complete clinical cure rate in the PF and BB groups, respectively. At week 4, the percentage of totally cured patients increased up to 95% (95% CI: 89-97%) and 91% (95% CI: 83-94%) in the PF and BB groups, respectively (P = NS between groups). At week 4, 5% in the PF group and 9% in the BB group complained of itching. Burning and irritation after treatment applications were more common in the BB group in comparison with the PF group. The tolerability score was better in the PF group in comparison with to BB group (2.9 vs. 2.2; P = 0.0001). A total of 95% of patients in the PV group had a good tolerability score (i.e. = 3) in comparison with 41% in the BB group. CONCLUSION: Our results show that a 3-day treatment with pyrethrins thermofobic foam is at least as effective as a 5-day treatment with benzyl benzoate lotion in convicted subjects with scabies. The foam formulation is better tolerated than the benzyl benzoate lotion.
BACKGROUND: It is possible to consider microcirculation as a kind of OwitnessO of the complex biological reactions triggered by the dialytic treatment. The reactivity of microcirculation to the dialytic stress may represent a measure of the overall biocompatibility of the membrane. In this study we tested the hypothesis that different synthetic membranes may have different biological effects, particularly related to microcirculation. SUBJECTS AND METHODS: In this crossover study, we observed 16 chronically hemodialyzed patients. All patients were treated with the EVAL membrane; we recorded the TcPO2 during the second treatment of the week. All patients were then switched to the hf-PS membrane. During the study observation we did not change the dialytic prescription or the pharmacologic treatment. RESULTS: From the beginning of the session until 90O, the behavior of TcPO2 is similar for both the membranes. From 120O to the end of the treatment in sessions with the EVAL membrane, the TcPO2 values come back to the starting level, whereas in the treatments with hf-PS the TcPO2, the values remain at a lower level; there was a significant difference between EVAL and hf-PS in the values recorded. Arterial blood gas values of paO2 and paCO2 are quite similar in the treatments with both the membranes, without any significant difference. CONCLUSIONS: The analysis of microcirculation by means of TcPO2 measurement is a useful tool to obtain a OclinicalO measure of biocompatibility of the dialytic treatment and different membranes may have different impacts on TcPO2.
The aim of this article was to review the main indications of laparoscopic colostomy. A series of 9 patients is reported, stressing the technical steps of laparoscopic colostomy. The laparoscopic approach in patients with unresectable colorectal cancer permit to avoidance mayor laparotomy. In conclusion this technique appears safe, feasible and effective.
INTRODUCTION: Superficial bladder cancer can be treated by transurethral resection (TUR) and adjuvant intravesical therapy. Intravesical bacillus Calmette-Guérin (BCG) has been proven to be more efficacious with respect to recurrence prevention than intravesical chemotherapy, although at the cost of more severe side effects. There is a need for a new treatment modality with higher efficacy and less toxicity. The subject of this study is the efficacy of local microwave hyperthermia and chemotherapy treatment in intermediate or high risk superficial transitional cell carcinoma (TCC) of the bladder. PATIENTS AND METHODS: Ninety eligible patients received adjuvant treatment with a combination of mitomycin-C (MMC) and local microwave hyperthermia. All patients had multiple or recurrent Ta or T1 TCC of the bladder and were classified as intermediate or high risk according to EAU criteria. In total, 41 patients were BCG failures. The treatment regimen included 6 to 8 weekly sessions followed by 4 to 6 monthly sessions. Follow-up consisted of video-cystoscopy and urine cytology every 3 months. All patients were observed for 2 years. RESULTS: Kaplan-Meier analyses of the total group (N = 90) indicated that 1 year after treatment only 14.3% (SE 4.5%) of all patients experienced a recurrence. After 2 years of follow-up the risk of recurrence was 24.6% (SE 5.9%). No progression in stage and grade was observed. CONCLUSION: Microwave induced hyperthermia combined with MMC has promising value in intermediate or high risk superficial bladder cancer patients compared to literature data of BCG and/or intravesical chemotherapy, particularly where other treatments, i.e. BCG, have failed.
OBJECTIVES: To evaluate the effectiveness of combined local bladder hyperthermia and intravesical chemotherapy for the treatment of patients with high-grade (G3) superficial bladder cancer. METHODS: Patients with G3 bladder tumors (Stage Ta or T1) were treated with combined intravesical chemotherapy with mitomycin-C and local radiofrequency hyperthermia of the bladder wall. The patients were treated with either a prophylactic protocol (40 mg mitomycin-C) after complete transurethral resection of all tumors or with an ablative protocol (80 mg mitomycin-C) when visible tumor was seen on video-cystoscopy or bladder biopsies were positive for carcinoma in situ. RESULTS: Combined chemo-thermotherapy was administered to 52 patients with high-grade superficial bladder cancer (40 patients with Stage T1 tumor, 11 with Ta, and 3 with concomitant or isolated carcinoma in situ). At a median follow-up of 15.2 months (mean 23, range 6 to 90), no stage progression to T2 or disease-related mortality had occurred. The bladder preservation rate was 86.5%. The prophylactic protocol was administered to 24 patients. After a mean follow-up of 35.3 months, 15 patients (62.5%) were recurrence free. The bladder preservation rate was 95.8%. The ablative protocol was administered to 28 patients. Complete ablation of the tumor was accomplished in 21 patients (75%). After a mean follow-up of 20 months, 80.9% of these patients were recurrence free. The bladder preservation rate for the ablative group was 78.6%. CONCLUSIONS: Combined local bladder hyperthermia and intravesical chemotherapy has a beneficial prophylactic effect in patients with G3 superficial bladder cancer. Ablation of high-grade bladder tumors is feasible, achieving a complete response in about three quarters of the patients.
S-glutathionylation, the reversible formation of mixed disulphides of cysteinyl residues in target proteins with glutathione, occurs under conditions of oxidative stress; this could be a posttranslational mechanism through which protein function is regulated by the cellular redox status. A novel physiological relevance of actin polymerization regulated by glutathionylation of Cys(374) has been recently suggested. In the present study we showed that glutathionylated actin (GS-actin) has a decreased capacity to polymerize compared to native actin, filament elongation being the polymerization step actually inhibited. Actin polymerizability recovers completely after dethiolation, indicating that S-glutathionylation does not induce any protein denaturation and is therefore a reversible oxidative modification. The increased exposure of hydrophobic regions of protein surface observed upon S-glutathionylation indicates changes in actin conformation. Structural alterations are confirmed by the increased rate of ATP exchange as well as by the decreased susceptibility to proteolysis of the subtilisin cleavage site between Met(47) and Gly(48), in the DNase-I-binding loop of the actin subdomain 2. Structural changes in the surface loop 39-51 induced by S-glutathionylation could influence actin polymerization in view of the involvement of the N-terminal portion of this loop in intermonomer interactions, as predicted by the atomic models of F-actin.
The prevalence of superficial transitional cell carcinoma of the bladder (STCCB) is still increasing in spite of improved adjuvant chemotherapeutic and/or immunoprophylaxis approaches. Thus, there is certainly an urgent need to improve our ability to control this disease. Local hyperthermia has a therapeutical potential for the treatment of many solid tumors, especially when used in combination with other treatments, such as radiation and chemotherapy. In particular, a synergistic or, at least, supra-additive anti-tumor cell killing effect was documented when local hyperthermia was administered in combination with selected cytostatic drugs. Recently, advances in miniaturized technology have allowed the development of a system specifically designed for delivering an endovesical thermo-chemotherapy regimen in humans. In preliminary clinical experiences, insofar mainly carried out as mono-institutional investigations, the combined treatment using this system was demonstrated to be feasible, minimally invasive and safe when performed on out-patient basis. Moreover, the anti-tumoral efficacy seemed to be significantly enhanced when compared with that obtained using intravesical chemotherapy alone for both adjuvant (prophylaxis) and neo-adjuvant (ablative) approaches to superficial bladder cancer.
A significant specific increase in the actin carbonyl content has been recently demonstrated in human brain regions severely affected by the Alzheimer's disease pathology, in postischemic isolated rat hearts, and in human intestinal cell monolayers following incubation with hypochlorous acid (HOCl). We have very recently shown that exposure of actin to HOCl results in the immediate loss of Cys-374 thiol, oxidation of some methionine residues, and, at higher molar ratios of oxidant to protein, increase in protein carbonyl groups, associated with filament disruption and inhibition of filament formation. In the present work, we have studied the effect of methionine oxidation induced by chloramine-T (CT), which at neutral or slightly alkaline pH oxidizes preferentially Met and Cys residues, on actin filament formation and stability utilizing actin blocked at Cys-374. Methionines at positions 44, 47, and 355, which are the most solvent-exposed methionyl residues in the actin molecule, were found to be the most susceptible to oxidation to the sulfoxide derivative. Met-176, Met-190, Met-227, and Met-269 are the other sites of the oxidative modification. The increase in fluorescence associated with the binding of 8-anilino-1-naphtalene sulfonic acid to hydrophobic regions of the protein reveals that actin surface hydrophobicity increases with oxidation, indicating changes in protein conformation. Structural alterations were confirmed by the decreased susceptibility to proteolysis and by urea denaturation curves. Oxidation of some critical methionines (those at positions 176, 190, and 269) causes a complete inhibition of actin polymerization and severely affects the stability of actin filaments, which rapidly depolymerize. The present results would indicate that the oxidation of some critical methionines disrupts specific noncovalent interactions that normally stabilize the structure of actin filaments. We suggest that the process involving formation of actin carbonyl derivatives would occur at an extent of oxidative insult higher than that causing the oxidation of some critical methionine residues. Therefore, methionine oxidation could be a damaging event preceding the appearance of carbonyl groups on actin and a major cause for the functional impairment of the carbonylated protein recently observed both in vivo and in vitro.
BACKGROUND: Several studies have provided convincing evidence that in apparently healthy subjects elevated serum levels of plasma C-reactive protein (CRP) are associated with an increased risk of experiencing myocardial infarction and sudden cardiac death. It has been claimed that, in dialytic patients, the hepatic synthesis of this 'acute phase response' plasma protein is primarily induced by the macrophage-derived interleukin 6 (IL-6). Little information is available, however, regarding CRP and IL-6 plasma levels in pre-dialytic renal failure. METHODS: Plasma CRP by a modification of the laser nephelometry technique, IL-6 and serum albumin were determined in 103 chronic pre-dialytic patients (mean age 50 +/- 6.3 years; creatinine clearance (Cr.cl.) 36.3 +/- 23.1 ml/min). RESULTS: CRP was >5 mg/l (normal upper range) in 42% of the global population. CRP and IL-6 were significantly related (r = 0.35, p < 0.0004). CRP and IL-6 were related to renal function (CRP vs. Cr.cl., r = -0.56, p < 0.0001; IL-6 vs. Cr.cl., r = -0.55, p < 0.0001, Spearman correlation coefficient). When patients were divided in tertiles according to renal function, CRP median value resulted 7.9 mg/l (interquartile interval: 5-12) in the first tertile (Cr.cl. <18.5 ml/min), 4.0 mg/l (3-6) in the second tertile (Cr.cl. 18.5-45 ml/min) and 3.2 mg/l (2.7-4.0) in the last tertile (Cr.cl. >45 ml/min) (p < 0.0001). A negative correlation between CRP and S-albumin was also found (r = -0.52, p < 0.0001, Spearman correlation coefficient). CONCLUSIONS: IL-6 and CRP were increased and were inversely related to creatinine clearance in our population of 103 chronic predialytic patients. The possibility of a decreased renal clearance of CRP and/or cytokines as a cause of an activated acute-phase response is discussed. A negative correlation between CRP and S-albumin was found confirming the link between chronic inflammation and malnutrition in chronic renal patients.
BACKGROUND: In this study we investigate the effects of parenteral immunotherapy on children below 5 years of age in order to prove the safety and clinical efficacy of dust mite specific immunotherapy (SIT) in such young patients. In young children, allergy is often due to dermatophagoides and causes a persistent inflammation that leads to recurrent respiratory infections. This condition impairs the normal development of airways by inducing remodelling. Although many paediatric allergists are used to treating young allergic children with SIT, this method is still subject to discussion. The benefits versus risks of SIT must also be defined. METHODS: In a case control study, 28 patients with dermatophagoides induced asthma and rhinitis treated with subcutaneous immunotherapy were assessed alongside a comparable control group. Symptom and drugs scores were collected from diary cards. RESULTS AND DISCUSSION: Scores proved to be significantly lower in the immunotherapy group in respect to the control group (p = 0.001). In particular, asthma attacks in the case group decreased significantly during the first year of treatment (p = 0.001). SIT was well tolerated and compliance was good. CONCLUSIONS: Our results confirm the safety and the efficacy of SIT in children below 5 years of age and above all, they confirm that SIT can begin at a very early age.
Actin is the major constituent of the cytoskeleton of almost all the eukaryotic cells. In vitro experiments have indicated that oxidant-stressed nonmuscle mammalian cells undergo remarkable changes in their morphology and in the structure of the actin cytoskeleton, often resulting in plasma membrane blebbing. Although the microfilament network is one of the earliest targets of oxidative stress, the mechanism by which oxidants change both the structure and the spatial organization of actin filaments is still a matter of debate and far from being fully elucidated. Starting from the 2-fold role of oxidants as injurious by-products of cellular metabolism and essential participants in cell signaling and regulation, this review attempts to gather the most relevant information related to (i) the activation of mitogen-activated protein (MAP) kinase stress-activated protein kinase-2/p38 (SAPK2/p38) which, via MAP kinase-activated protein (MAPKAP) kinase 2/3, leads to the phosphorylation of the actin polymerization (F-actin) modulator 25/27 kDa heat shock protein (HSP25/27), whose phosphorylation is causally related to the regulation of microfilament dynamics following oxidative stress; (ii) the alteration of the redox state of actin or some actin regulatory proteins. The actin cytoskeleton response to oxidants is discussed on the basis of the growing body of evidence indicating the actin system as the most sensitive constituent of the cytoskeleton to the oxidant attack.
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Tumor pretargeting with biotinylated antibody/avidin complexes improves the therapeutic index of systemically administered biotin-tumor necrosis factor (TNF) conjugates. Since the number of biotins in this conjugate is known to be critical for activity, we have characterized the structure of different biotin-TNF conjugates, prepared by reaction with d-biotinyl-6-aminocaproic acid N-hydroxysuccinimide ester and identified the biotinylation sites by trypsin digestion, reverse-phase chromatography, and electrospray mass spectrometry analyses. The results have shown that N-terminal valine is a preferential biotinylation site at pH 5.8, half of biotins being located on the alpha-amino group of this residue in a conjugate bearing one biotin/trimer (on average). Moreover, evidence has been obtained to suggest that the remaining part of biotins are linked to the epsilon-amino group of lysine 128, 112, and 65, while lysine 11, 90, and 98 were practically unmodified. No evidence of O-biotinylation of serine, threonine and tyrosine was obtained.
The number of protein-bound carbonyl groups is an established marker of protein oxidation. Recent evidence indicates a significant increase in actin carbonyl content in both Alzheimer's disease brains and ischemic hearts. The enhancement of actin carbonylation, causing the disruption of the actin cytoskeleton and the loss of the barrier function, has also been found in human colonic cells after exposure to hypochlorous acid (HOCl). Here, the effects of oxidation induced by HOCl on purified actin are presented. Results show that HOCl causes a rapidly increasing yield of carbonyl groups. However, when carbonylation becomes evident, some Cys and Met residues have been already oxidized. Covalent intermolecular cross-linking as well as some noncovalent aggregation of carbonylated actin have been found. The covalent cross-linking, unaffected by reducing and denaturing agents, parallels an increase in dityrosine fluorescence. Moreover, HOCl-mediated oxidation induces the progressive disruption of actin filaments and the inhibition of F-actin formation. The molar ratios of HOCl to actin that lead to inhibition of actin polymerization seem to have effect only on cysteines and methionines. The process that involves oxidation of amino acid side chains with formation of a carbonyl group would occur at an extent of oxidative insult higher than that causing the oxidation of some critical amino acid residues. Therefore, the increase in actin content of carbonyl groups found in vivo would indicate drastic oxidative modification leading to drastic functional impairments.
Creatine supplementation in humans has been reported to enhance power and strength both in normal subjects and in patients with various neuromuscular diseases. The purpose of this study was to examine the effects of supplementation on exercise performance and maximal voluntary isometric muscular contraction (MVIC) in Amyotrophic Lateral Sclerosis (ALS) patients. We report the results obtained in 28 patients with probable/definite ALS. In each patient we acquired the dynamometric measurement of MVIC in 10 muscle groups of upper and lower limbs and a measure of fatigue by means of an high-intensity intermittent protocol in elbow flexors and knee extensors muscles. All patients completed the protocols at the baseline and after supplementation of 20 g per day for 7 days and after supplementation of 3 g per day for 3 and 6 months. MVIC increased after 7 days of supplementation in 20 patients (70%) in knee extensors and in 15 (53%) of them also in elbow flexors. A statistically significant difference between pre and post-treatment mean values of MVIC was found both in elbow flexors (P<0.05) and knee extensors (p<0.04). The analysis of the slopes of fatigue test showed a statistically significant improvement after 7 days of supplementation in 11 patients (39%) in elbow flexors and in 9 patients (32%) also in knee extensors muscles. During the 6-month follow-up period all the examined parameters showed a linear progressive decline. In conclusion, our preliminary results have demonstrated that supplementation temporary increases maximal isometric power in ALS patients so it may be of potential benefit in situations such as high intensity activity and it can be proposed as a symptomatic treatment.