[Bean or blue rubber blue nevus syndrome. Presentation of 6 patients]

INTRODUCTION/AIMS

Bean or Blue Rubber Bleb Nevus Syndrome (BRBNS) is an uncommon disease characterized by multifocal venous malformations that predominantly affect the skin, soft tissues and gastrointestinal tract. Our objective is to familiarize the pediatric surgeon with this condition, promoting early diagnosis and seriated surgical treatment as therapeutic options. We have reviewed the diagnosis and treatment of 6 patients treated from 1993 to 2009.

MATERIAL AND METHODS

All the patients had a venous malformation (> 10 cm) that acted as a marker. After, characteristic skin lesions appeared as well as chronic anemia due to digestive bleeding associated to hypofibrinogenemia. Age of appearance of the anemic picture varied from 6 months to 7 years, it being more aggressive the earlier its appearance. The diagnosis of the disease was made by endoscopically. All the patients required transfusion with blood derivatives 5 to 25 times a year. Treatment was multidisciplinary: periodic transfusions in every case, endoscopic sclerosis in lesions that affect the colon or stomach and surgical treatment for lesions of the jejunum and ileum. In two of these patients, 23 and 46 lesions were excised, respectively. In the last year, the tendency has been to use enterotomy and fulguration with Argon.

RESULTS

The patients who have undergone excision of the digestive malformations have experienced a significant decrease in their transfusion needs. One female patient with miliary dissemination died.

CONCLUSIONS

BRBNS is a difficult to diagnose due to its low frequency. Treatment of gastrointestinal tract lesions is multidisciplinary, combining endoscopic and surgical techniques that decrease transfusions and improve the quality of life of the patients.

[Indication for early excision of the giant congenital nevus]

INTRODUCTION

Most of specialists involved in giant congenital nevi (GCN) care, agree that the risk of melanoma is probably not significant enough to warrant the prophylactic removal of all those lesions. However, many patients benefit from very early surgical procedures.

MATERIAL AND METHODS

In the last 15 years 41 children undergwent surgical removal of their large or giant melanocityc lesions in the first year of life at our institution. Indications for such an early excision were as follows: painful ulceration or bleeding, alarming dermatoscopic changes, location in the scalp being removable with primary closure, concomitant surgical procedures, multiple expected interventions and severe parental psychosocial distress.

RESULTS

All patients had a good cosmetic result. All nevus in the scalp between 3 and 5 cms were removed with a primary closure in order to avoid future need of scalp expansion. Familial psychological distress improved significantly and disturbances related to scholar activities were not noticed.

CONCLUSIONS

Despite the lack of international consensus regarding the appropriate timing for large or giant congenital nevi excision, a selection of patients and their families can benefit from early surgical removal.

[Bladder malformations in a model of myelomeningocele. Preliminary report]

PURPOSE

To describe the presence of bladder malformations in a surgically induced model of myelomeningocele (MMC).

METHODS

A MMC like defect was created in the mid gestation using the previously described model in sheep. Bladders were examined macroscopically and histopathological changes were assessed using H-E.

RESULTS

Non prenatally corrected animals presented dilated bladders and separation between muscle bundles. Those malformations were not found in corrected animals or controls.

CONCLUSIONS

Some bladder changes can be described in a surgically-induced model of MMC. These changes could be prevented using open fetal surgery.

Ag-doped manganite nanoparticles: new materials for temperature-controlled medical hyperthermia

The purpose of this study was to introduce newly synthesized nanomaterials as an alternative to superparamagnetic ironoxide based particles (SPIO) and thus to launch a new platform for highly controllable hyperthermia cancer therapy and imaging. The new material that forms the basis for this article is lanthanum manganite particles with silver ions inserted into the perovskite lattice: La(1-x)Ag(x)MnO(3+delta). Adjusting the silver doping level, it is possible to control the Curie temperature (T(c)) in the hyperthermia range of interest (41-44 degrees C). A new class of nanoparticles based on silver-doped manganites La(1-x)Ag(x)MnO(3+delta) is suggested. New nanoparticles are stable, and their properties were not affected by the typical ambient conditions in the living tissue. It is possible to monitor the particle uptake and retention by MRI. When these particles are placed into an alternating magnetic field, their temperature increases to the definite value near T(c) and then remains constant if the magnetic field is maintained. During the hyperthermia procedure, the temperature can be restricted, thereby preventing the necrosis of normal tissue. A new class of nanoparticles based on silver-doped manganites La(1-x)Ag(x)MnO(3+delta) was suggested. Ag-doped perovskite manganites particles clearly demonstrated the effect of adjustable Curie temperature necessary for highly controllable cellular hyperthermia. The magnetic relaxation properties of the particles are comparable with that of SPIO, and so we were able to monitor the particle movement and retention by MRI. Thus, the new material combines the MRI contrast enhancement capability with targeted hyperthermia treatment.

[Prenatal techniques to prevent central nervous system malformations in the surgically induced model of myelomeningocele]

AIM

To describe central nervous system malformations in the surgically induced model of Myelomeningocele (MMC) and their prevention using different prenatal treatments.

METHODS

MMC was surgically created in 33 fetal lambs. Fifteen did not undergo fetal repair (group A). Of the lambs that did undergo repair, 10 were repaired with open two layer surgical closure (group B), 5 with fetoscopic coverage using bioglue (group C) and 3 fetoscopically using a patch (group D). All procedures were recorded and lamb brains and spinal cords were examined grossly and microscopically in coronal sections for structural organization anomalies. Histopathological changes were assessed using HE and S-100 neural marker.

RESULTS

Hydrocephalus, Arnold-Chiari type II (AC-II) malformation and some neuronal migration disorders were observed in group A. Brains from group B and D were not hydrocephalic and had neither cell migration disorders nor hindbrain herniation. Group C presents mild degrees of hydrocephalus and AC-II. In group C lumbar lesion was covered by fibrous tissue.

CONCLUSIONS

Some of the central nervous system abnormalities observed in human disease are present in the surgically induced model of MMC. In this model avoidance of fluid drainage using open fetal surgery limits malformation severity.

Transport of prion protein across the blood-brain barrier

The cellular form of the prion protein (PrP(c)) is necessary for the development of prion diseases and is a highly conserved protein that may play a role in neuroprotection. PrP(c) is found in both blood and cerebrospinal fluid and is likely produced by both peripheral tissues and the central nervous system (CNS). Exchange of PrP(c) between the brain and peripheral tissues could have important pathophysiologic and therapeutic implications, but it is unknown whether PrP(c) can cross the blood-brain barrier (BBB). Here, we found that radioactively labeled PrP(c) crossed the BBB in both the brain-to-blood and blood-to-brain directions. PrP(c) was enzymatically stable in blood and in brain, was cleared by liver and kidney, and was sequestered by spleen and the cervical lymph nodes. Circulating PrP(c) entered all regions of the CNS, but uptake by the lumbar and cervical spinal cord, hypothalamus, thalamus, and striatum was particularly high. These results show that PrP(c) has bidirectional, saturable transport across the BBB and selectively targets some CNS regions. Such transport may play a role in PrP(c) function and prion replication.

[Tuberculosis of the breast: imaging findings in two patients]

Diagnosis of breast tuberculosis is difficult and rare in western countries. We describe two cases of mammary tuberculosis, with mastitis as clinical feature that fail to heal despite antibiotic therapy. Mammographic findings showed a large opacity involving the entire breast in case 1, and a focal asymmetric density with irregular margins in case 2. Sonographic findings revealed in both cases hypoechoic nodules with fistulous tracks and axillary lymph nodes. Magnetic resonance was performed in one case, which showed parenchymal asymmetry with heterogeneous enhancement including irregular internal ring enhancement. Fine needle aspiration cytology revealed inflammatory cells in first case and atypical cells in second case. Core needle biopsy was performed in both cases to rule out malignant lesions. Acid-fast bacilli were negative in both patients while polymerase chain reaction was positive in one case. There was a good clinical response to antituberculosis therapy.

Cypermethrin effects on the adult mice seminal glands

The insecticide cypermethrin acts upon the sodium channels. Their effects over animal health are not understood. Here, the effects of cypermethrin on the seminal glands (SGs) are studied (1/5 DL50 i.p.). Forty-five adult mice (CF1) were distributed in three groups: (1) untreated, (2) vehicle (oil), and (3) experimental (cypermethrin in oil). The animals were sacrificed at 1 and each 8.6 days. The SGs were processed for histology: Haematoxylin/P.A.S, Thyonin (0.6%) and Immunohistochemistry (Ki-67). In the SGs was quantified: the epithelium height, mastocytes, and cell proliferation. In the results, cypermethrin exerts an intense effect on epithelium height and cell proliferation. A net increase of both parameters was observed at 24 h (p0.05). However, the mastocytes increased drastically and progressively during the experimental period (p0.05). Then, the effects have acute manifestations, which would be responsible for the potential changes in the male's reproductive potentiality.

Brain malformations in the sheep model of myelomeningocele are similar to those found in human disease: preliminary report

PURPOSE

To examine if brain malformations, similar to those which account for cognitive disorders seen in human disease, are present in an ovine model of myelomeningocele (MMC).

METHODS

An MMC-like lesion was surgically created in 16 fetal lambs between 60 and 80 days of gestation. Ten did not undergo fetal repair (group A), 2 were repaired with an open two-layer closure (group B), 2 with open bioglue coverage (group C) and 2 with fetoscopic coverage (group D). Lambs were killed and their brains were examined. Two brains from normal unoperated lambs served as controls.

RESULTS

Thirteen lambs died in utero (81%). Two lambs in group A and 1 in group B were delivered at term. Group A brains showed hydrocephalus and extensive areas of polymicrogyria. There was also an extensive denudation of the ependymal lining under the polymicrogyric areas and the corpus callosum was thinner than normal. No hindbrain herniation was observed. Brains from group B and the control did not show any of these abnormalities.

CONCLUSIONS

Some of the central nervous system abnormalities associated to MMC in human patients are also found in the uncorrected fetal lamb model of MMC but not in the only survivor to intrauterine coverage. Further studies are necessary to ascertain if these abnormalities can be prevented by coverage of the defect.

Processing noxious information at the subnucleus reticularis dorsalis (SRD) of anesthetized cats: wind-up mechanisms

With the exception of one monkey's study, where wind-up was not reported, electrophysiological data from SRD neurons were obtained in rodents where they show wind-up. This work was designed to examine the response properties of SRD neurons in anesthetized cats to study how general the data from rats may be. Since cat's SRD cells showed wind-up, its underlying mechanisms were approached, an issue not previously addressed at supraspinal level. Electrical stimulation, extracellular (combined with microiontophoresis) and intracellular techniques revealed that A delta information reaches the SRD via the ventrolateral cord, whereas C information preferentially follows a dorsal route. Wind-up was usually generated by spinal and peripheral stimulation, but it was also evoked either by stimulating the nucleus reticularis gigantocellularis (NRGc), even after spinal cord section and bilateral full thickness removal of the cerebral cortex, or by applying microiontophoretic pulses of l-glutamate at 0.3-1 Hz. Wind-up relied on afferent repetitive activity gradually depolarizing the SRD neurons leading 3-4.5 Hz subthreshold membrane rhythmic activity to threshold. Riluzole retarded wind-up generation and decreased the number of spikes per stimulus during wind-up. GABA or glycine abolished spontaneous and sensory-evoked activity and bicuculline, but not strychnine, increased spontaneous and stimulus-evoked activity. These results demonstrate that wind-up at the SRD is not merely the reflection of spinal wind-up, but (i) can be locally generated, (ii) is partially dependent upon persistent sodium currents, and (iii) is under the modulation of a tonic GABAa-dependent inhibition decreasing SRD excitability. Injury and/or inflammation producing tonic C-fiber activation will surpass tonic inhibition generating wind-up.

[Morbility and mortality associated with prosthetic patch in congenital diaphragmatic hernia]

AIM

To analyze morbility, mortality and neonatal intensive care management in CDH patients who required a prosthetic patch to close the diaphragmatic defects, and to compare these results with those who were made a primary closure.

MATERIAL AND METHODS

We reviewed the clinical charts of CDH patients managed at our institution between January 1994 and December 2006, including demographic data, clinical management, treatment options, complications and mortality. Appropriate statistical tests were used to evaluate the data: mortality, need of high frequency oscillatory ventilation (HFOV), days of intubation, days of total parenteral nutrition (TPN), days of admission, reherniation, need of Nissen funduplication and intestinal obstruction; a p value less than 0.05 was considered statistically significant.

RESULTS

Eighty-seven CDH patients were reviewed, 68 right, 17 left and 2 bilateral defects. Seventeen died before surgery (19.5%). Among the 70 operated patients, 21 (24.1%) required a prosthetic patch, 18 in the left and 3 in the right side. Overall mortality, need of HFOV, intubation days, need of TPN, days of admission, reherniation rate and need of Nissen funduplication were all significantly worse in the group who required a patch. Rate of intestinal obstruction was similar in both groups.

CONCLUSIONS

Patients who required a prosthetic patch to close the diaphragmatic defect suffered from higher morbidity and presented a higher mortality than those who did not required the patch.

[A satisfaction survey of the evolution of 238 otoplasty]

PURPOSE

The prominent ear is a frequent problem that can be a source of important psychosocial troubles. The aim of this paper has been to evaluate the psychosocial repercussion, cosmetic result and degree of satisfaction in patients treated at our Institution for prominent ears in the last 4 years.

MATERIAL AND METHODS

A questionnaire has been sent to 127 patients. All of them underwent Mustarde's otoplasty.

RESULTS

238 otoplasty were performed in 127 patients (87% bilateral procedures). The mean age was 8.15 +/- 3.25 years (range: 1-15 years), with a follow-up of 27.15 +/- 13.62 months (range: 4-52 months). Sixty-two % of the patients underwent otoplasty without having self-image affected while 38% of the group were patients older enough to see surgery to correct a long-standing defect. Patients did not require a period of postoperative psychosocial adjustment to their new appearance. Two patients described their results of surgery as little improvement. Three undergo partial recurrence and 5 suffered from total recurrence. All of the patients resume their lives with an improved level of self confidence. Conclusions. Otoplasty is a safe procedure for prominent ears to be considered in children with psycosocial, emotional or behavioural effects.

[Complex lymphatic malformations: diagnostic and therapeutical implications]

BACKGROUND

Complex lymphatic malformations (CLM) consist of disturbances of lymphatic system development, most often with a genetic origin and with mixed vascular system involvement: lymphatic, venous and capillary. They affect a large corporal area or are associated to other syndromes or systemic diseases.

METHODS

We reviewed 21 patients with CLM treated in our hospital during the last 15 years. We used D2-40 monoclonal antibody (by immunohistochemistry) as lymphatic marker to evaluate the level of lymphatic involvement. Furthermore we analysed surgical implications in this group of patients.

RESULTS

Twelve children had only lymphatic involvement and nine mixed lymphatic-capillary or lymphatic-venous one. Two died of: respiratory insufficiency (in the neonatal period) and refractory hypoproteinemia (at 8 years of age). The skin was affected between 10 and 35% of total body surface. Three patients suffered from visceral involvement (lungs and mediastinum) and eighteen musculoskeletal. Severe deformity (20), lymphorhagia (15), repeated lymphangitis and chronic pain (5) were the most common symptoms reported. The immunoreaction intensity with monoclonal antibody D2-40 was related to the severity of the local and systemic involvement as well as to the presence of associated malformations. Fifteen cases underwent sequential surgical treatment, seven were treated with sclerotherapy (OK-432) and four with CO2 laser vaporization. Residual lymphorhagia in patients with total extirpation of the lymphatic malformation stopped after repeated evacuator punctures and healing took place.

CONCLUSIONS

(1) D2-40 monoclonal antibody is a marker of bad prognosis in CLM. (2) The complete excision of the lymphatic malformation lead to healing and the associated lymphorragia should not be considered as a recurrence, which will stop with evacuator punctures in all cases. (3) A multidisciplinary team approach is essential for the proper care of CLM in order to minimize postoperative sequelae and late complications.

Disrupting beta-amyloid aggregation for Alzheimer disease treatment

Alzheimer's disease is a devastating degenerative disorder for which there is no cure or effective treatment. Although the etiology of Alzheimer's disease is not fully understood, compelling evidence indicates that deposition of aggregates composed by a misfolded form of the amyloid beta peptide (Abeta) is the central event in the disease pathogenesis. Therefore, an attractive therapeutic strategy is to prevent or reverse Abeta misfolding and aggregation. Diverse strategies have been described to identify inhibitors of this process, including screening of libraries of small molecules chemical compounds, rational design of synthetic peptides, assessment of natural Abeta-binding proteins and stimulation of the immune system by vaccination. In this article we describe these different approaches, their principles and their potential strengths and weaknesses. Overall the available data suggest that the development of drugs to interfere with Abeta misfolding and aggregation is a feasible target that hold great promise for the treatment of Alzheimer's disease.

[How can we improve symptomatic hypotension in hemodialysis patients: cold dialysis vs isothermic dialysis]

BACKGROUND

Symptomatic hypotension is the most frequent acute complication affecting patients during chronic hemodialysis treatment sessions. Many reports have demonstrated that the use of cool dialysate has a protective effect on blood pressure during hemodialysis treatments. In the present study, we investigated whether preventing the hyperthermic response had favourable effects on hemodynamic stability during the hemodialysis procedure while affording good tolerance to patients.

METHODS

We investigated the effect of thermal control of dialysate on hemodynamic stability in hypotension-prone patients in our center. Patients were eligible for the study if they had symptomatic hypotensive episodes (> 3/12session/ month) during the screening phase. The study was designed with two phases for the same selected patients and two treatment arms, each phase lasting 4 weeks. In the first phase, we adjusted dialysate temperature on 36 masculineC for 12 sessions (cold dialysis) and in the second phase we used a device allowing the regulation of thermal balance (Blood Temperature Monitor; Fresenius Medical Care, Bad Homberg, Germany), that keep body temperature unchanged (isothermic dialysis).

RESULTS

Nine HD patients were enrolled and completed the study. During the screening phase the mean ultrafiltration was 4 1% of dry weight, and blood pressure decreased from 9916 to 8016 mm Hg (p<0.001). In 5.01.7 sessions of 12 treatments were complicated by hypotension. In the first and second phase we observed a decrease of complicated treatments with symptomatic hypotension (5.01.7 versus 2.71.6 y 2.81.7; p<0.01). Both procedures: Cold dialysis and Isothermic dialysis was well tolerated by patients.

CONCLUSION

Results show that active control of body temperature can significantly improve intradialytic tolerance in hypotension-prone patients.

The intriguing prion disorders

Prion diseases are among the most intriguing illnesses. Despite their rare incidence, they have captured enormous attention from the scientific community and general public. One of the most hotly debated issues in these diseases is the nature of the infectious material. In recent years increasing evidence has emerged supporting the protein-only hypothesis of prion transmission. In this model PrPSc (the pathological isoform of the prion protein, PrPC) represents the sole component of the infectious particle. However, uncertainties about possible additional factors involved in the conversion of PrPC into PrPSc remain despite extensive attempts to isolate and characterize these elusive components. In this article, we review recent developments concerning the protein-only hypothesis as well as the possible involvement of cellular factors in PrPC to PrPSc conformational change and their influence on the pathogenesis of prion diseases.

Inhibition of protein misfolding and aggregation by small rationally-designed peptides

Several human diseases are associated with the presence of toxic fibrillar protein deposits. These diseases called protein misfolding disorders, are characterized by the accumulation of misfolded protein aggregates in diverse tissues. Strong evidence indicates that the conversion of a normal soluble protein into a beta-sheet-rich oligomeric structure and further fibrillar aggregation are the key events in the disease pathogenesis. Therefore, a promising therapeutic target consists of the prevention and dissolution of misfolded protein aggregates. Peptides designed to specifically bind to the pathogenic protein and block and/or reverse its abnormal conformational change constitute a new class of drugs. This article reviews this approach, describing diverse compounds reported to have this activity.

Phase III study of gemcitabine plus vinorelbine (VG) versus vinorelbine (V) in patients (pts) with metastatic breast cancer (MBC) previously treated with anthracyclines (A) and taxanes (T). Final results of GEICAM 2000–04 study

575

Background: VG has shown to be efficacious and safe in MBC in pts previously treated with AT. This study compared treatment (TT) V with the combination of VG. Primary objective was progression free survival (PFS). Methods: pts previously treated with AT, aged ≥18, ECOG ≤ 2, were randomized to V: 30 mg/m2 day (d) 1, d8, or VG 30/1200 mg/m2 d1, d8, both every 21 days until disease progression. Stratification criteria were previous lines of TT for MBC (0 vs.1 vs.2) and visceral disease (yes vs. no). 126 pts per arm were needed to demonstrate a prolongation in PFS of 2 months (m) (from 3 to 5; HR = 1.67; α and β errors 0.05 and 10). Results: 252 pts (127 V and 125 VG) were recruited between 2001 and 2005. Arms were well balanced: median age was 57 years; median number of metastatic sites 2; visceral disease was present in 75% of pts; 17%, 53% and 29% of pts received study TT as first, second and third line respectively. Median number of cycles were 4 (1–21) in V and 6 (1–26) in VG. Median PFS was 6.3 m (95% CI, 5.3–7.3) for VG and 4.1 m (95% CI, 3.3–4.9) for V (p=0.0011). Objective response rate was 37% (CI 95% 29–46) for VG and 25% (CI 95%: 17–33) for V (p= 0.035). CTC grade 3–4 hematologic toxicity was significantly higher with VG vs. V (65% vs. 43% neutropenia, 33% vs. 17% leucopenia, and 11% vs. 2% thrombocytopenia); febrile neutropenia was present in 10.5% of pts on VG and 6% of pts in V (p=ns). Non-hematological toxicity was low and manageable in both arms. Conclusions: VG demonstrated significant efficacy advantages over V in pts with MBC previously treated with AT, with manageable toxicity. This favorable risk-benefit profile supports the use of this combination in this patient population.

[Table: see text]

Capecitabine (X) and taxanes in patients (pts) with anthracycline-pretreated metastatic breast cancer (MBC): Sequential vs. combined therapy results from a MOSG randomized phase III trial

570

Introduction: Capecitabine (Xeloda [X]) shows synergy with taxanes and adding X to docetaxel (T) extends overall survival (OS), response rate (RR) and progression free-survival (PFS) beyond T alone. Sequential single-agent therapy could confer convenience benefits and may be more appropriate than combination chemotherapy for some pts. Methods: Pts with anthracycline-pretreated MBC received 3-weekly cycles of 1 of the following regimens: X→taxane (X 1250mg/m2 bid d1–14, followed after progression (PD) by T 100mg/m2 or paclitaxel [P] 175mg/m2 day 1; X+P (X 825mg/m2 bid days 1–14 + P 175mg/m2 day 1) or X+T (X 825mg/m2 bid days 1–14 + T 75mg/m2 day 1). Results: Of the 368 pts enrolled, 91 are either still on therapy or not evaluable. The table shows baseline characteristics, efficacy and safety in evaluable pts. Median follow up is 15.5 months. Median doses for X in each arm (1st cycle vs. 8th cycle, mg/m2 bid): 1218 vs. 1054; 948 vs. 900; 846 vs. 751. Median doses for P and T (1st cycle vs. 8th cycle, mg/m2): 173 vs. 169 and 75 vs. 72, respectively. In the X→taxane arm, 58 pts (64%) received sequential taxane; the remainder did not receive a taxane, either because they were still on X, had CR or had rapid PD. Conclusions: RR is higher with XP and XT, but PFS and OS are similar at a median follow-up of 15.5 months. All regimens were well tolerated with minimal grade 4 AEs. Because there is no clear superiority of sequential vs. combined therapy, pt characteristics are likely to be used to decide which regimen is the most appropriate.

[Table: see text]

[Table: see text]

Pomegranate juice supplementation in chronic obstructive pulmonary disease: a 5-week randomized, double-blind, placebo-controlled trial

OBJECTIVE

The aim of the present study is to investigate the effect of antioxidant polyphenol-rich pomegranate juice (PJ) supplementation for 5 weeks on patients with stable chronic obstructive pulmonary disease (COPD), since the oxidative stress plays a major role in the evolution and pathophysiology of COPD.

DESIGN

A randomized, double-blind, placebo-controlled trial was conducted.

SUBJECTS

A total of 30 patients with stable COPD were randomly distributed in two groups (15 patients each).

INTERVENTIONS

Both groups consumed either 400 ml PJ daily or matched placebo (synthetic orange-flavoured drink) for 5 weeks. Trolox Equivalent Antioxidant Capacity (TEAC) of PJ, blood parameters (14 haematological and 18 serobiochemical), respiratory function variables, bioavailability of PJ polyphenols (plasma and urine) and urinary isoprostane (8-iso-PGF(2alpha)) were evaluated.

RESULTS

The daily dose of PJ (containing 2.66 g polyphenols) provided 4 mmol/l TEAC. None of the polyphenols present in PJ were detected in plasma or in urine of volunteers. The most abundant PJ polyphenols, ellagitannins, were metabolized by the colonic microflora of COPD patients to yield two major metabolites in both plasma and urine (dibenzopyranone derivatives) with no TEAC. No differences were found (P > 0.05) between PJ and placebo groups for any of the parameters evaluated (serobiochemical and haematological), urinary 8-iso-PGF(2alpha), respiratory function variables and clinical symptoms of COPD patients.

CONCLUSIONS

Our results suggest that PJ supplementation adds no benefit to the current standard therapy in patients with stable COPD. The high TEAC of PJ cannot be extrapolated in vivo probably due to the metabolism of its polyphenols by the colonic microflora. The understanding of the different bioavailability of dietary polyphenols is critical before claiming any antioxidant-related health benefit.

SPONSORSHIP

'Fundación Séneca' (Murcia, Spain), Project PB/18/FS/02 and Spanish CICYT, Project AGL2003-02195.

GABA(B) receptor-mediated modulation of cutaneous input at the cuneate nucleus in anesthetized cats

This study examined the modulatory influence exerted by GABA(B) receptors on the transmission of cutaneous afferent input to cuneate nucleus neurons in anesthetized cats. Electrical stimulation at the center of a receptive field activated cuneate nucleus cells at latencies of < or = 7 ms whereas stimulation at neighboring sites (receptive field edge) increased the response latency. Extracellular recording combined with microiontophoresis demonstrated that GABA(B) receptors are tonically active. Blockade of GABA(B) receptors prolonged sensory-evoked response durations and decreased times of occurrence of successive bursts whereas the agonist baclofen suppressed both these effects. Ejection of baclofen delayed the evoked response from the receptive field edge with respect to the receptive field center response and inhibited responses from the receptive field edge more effectively than responses from the receptive field center. From these results it is concluded that activation of GABA(B) receptors precludes cuneate cells from reaching firing threshold when afferent inputs are weak, spatially modulate cuneate nucleus excitability, play a major role in temporal pattern of discharges, and shape cutaneous receptive fields.

Role of endogenous channels in red blood cells response to their exposure to the pore forming toxin Sticholysin II

Sticholysin II (St II) is a highly hemolytic cytolysin isolated from the sea anemone Stichodactyla heliantus. The toxin hemolytic action takes place through the formation of channels that provoke an electrolyte unbalance leading to osmotic shock. The lytic event must involve the exchange of electrolytes and the entrance of water, leading to red blood cell disruption. These processes can occur through St II pores and/or the endogenous red blood cells transporters. In order to evaluate the contribution of these channels to water, anion and cation transport, we have measured the hemolysis and K+ efflux rates in the presence of several specific inhibitors. The results obtained in the presence of Hg, an AQP1 blocker, indicate that water transport through these channels is not essential for the occurrence of the lytic process induced by St II. The data also support a partial role of K+ and anion transporters. In particular, they are compatible with a preferential K+ efflux though the K(+)/Cl- co-transport as a response to the promoted swelling. Furthermore, they suggest that chloride influx, a process that can regulate both K+ efflux and lysis, is partially mediated by the endogenous cell transporters, in particular, band-3 anion exchange system being relevant at early stages of the lytic process.

Winery solid residue revalorization into oil and antioxidant with nutraceutical properties by an enzyme assisted process

Revalorization of the winery industry residue, grape seed is studied for the production of an oil and defatted meal with nutraceutical properties. Conventional grape seed oil extraction process is carried out by pressing at high temperature affecting the product quality. Oil extraction by cold pressing improves product quality, but it gives a low oil yield. Oil extracted is increased at the pressing stage, when an enzymatic pre-treatment is incorporated in to the conventional process. The yield is determined by determining the residual oil in the pressed cake. Using an enzymatic treatment during 9 hours at 45 degrees C and 50% of moisture, with a mixture of two commercial enzymes grape seed oil extraction yield by cold pressing is raised up to 72%, being a 59.4% increment in comparison to the yield obtained by the control, without enzymes. The defatted meal by enzimatic assisted process improves its phenolic compounds between 2 and 4 times, depending on the conditions of phenolics extraction in comparison to the control samples.

Radiology of bacterial pneumonia

Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings.

Beta-sheet breakers for Alzheimer's disease therapy

A growing wealth of evidence indicates that the key pathological event in Alzheimer's disease is the conversion of the normal soluble amyloid-beta peptide into beta-sheet-rich oligomeric structures which have a neurotoxic activity and ability to form insoluble amyloid deposits that accumulate in the brain. Beta-sheet breakers constitute a new class of drugs that are designed to specifically bind amyloid-beta peptide and block and/or reverse this abnormal conformational change. In this article we review this approach, describe diverse compounds reported to have this activity and summarize the data supporting the view that beta-sheet breakers could be serious candidates to combat this devastating disease.

Beta-sheet breaker peptide prevents Abeta-induced spatial memory impairments with partial reduction of amyloid deposits

Current evidence supports the notion that beta-amyloid deposits or Abeta intermediates may be responsible for the pathogenesis in Alzheimer's disease (AD) patients. In the present work, we have assessed the neuroprotective effect of the chronic intraperitoneal administration of a five-amino-acid beta-sheet breaker peptide (iAbeta5p) on the rat behavioral deficit induced by the intrahippocampal Abeta-fibrils injection. At 1 month after the injection, animals showed a partial reduction of the amyloid deposits formed and a decreased astrocytic response around the injection site. More importantly, we report that following the iAbeta5p treatment, hippocampal-dependent spatial learning paradigms, including the standard Morris water maze and a working memory analysis, showed a significant prevention from impairments induced by Abeta deposits in the dorsal hippocampus. Thus, it is possible that a noninvasive treatment such as the one presented here with beta-sheet breaker peptides may be used as a potential therapy for AD patients.

Silymarin induces recovery of pancreatic function after alloxan damage in rats

Alloxan has been widely used to produce experimental diabetes mellitus syndrome. This compound causes necrosis of pancreatic beta-cells and, as is well known, induces oxidant free radicals which play a relevant role in the etiology and pathogenesis of both experimental and human diabetes mellitus. Previously we have reported hypoglycemic and antilipoperoxidative actions of silymarin in serum and pancreatic tissue respectively. The aim of this study was to test whether silymarin could reduce the hyperglycemia and revert the pancreatic damage in alloxan treated rats, tested with silymarin in two protocols: using both compounds simultaneously for four or eight doses, or using the compound 20 days after alloxan administration for 9 weeks. Serum glucose and insulin were determined, and pancreatic fragments were used for histology and insulin immunohistochemistry. Pancreatic islets were isolated to assess insulin and Pdx1 mRNA expression by RT-PCR. Our results showed that 72 hours after alloxan administration, serum glucose increased and serum insulin decreased significantly, whereas pancreatic tissue presented morphological abnormalities such as islet shrinkage, necrotic areas, loss of cell organization, widespread lipoid deposits throughout the exocrine tissue, and loss of beta cells, but insulin and glucagon immunoreactivity was scattered if any. In contrast the pancreatic tissue and both insulin and glucose serum levels of rats treated with silymarin were similar to those of control animals. In addition, insulin and glucagon immunoreactive cells patterns in Langerhans islets were also normal, and normal insulin and Pdx1 mRNA expression patterns were detected during pancreatic recovery in Langerhans islets. The overall results suggest that silymarin induces pancreatic function recovery demonstrated by insulin and glucagon expression protein and normoglycemia after alloxan pancreatic damage in rats.

Intracuneate mechanisms underlying primary afferent cutaneous processing in anaesthetized cats

The cutaneous primary afferents from the upper trunk and forelimbs reach the medial cuneate nucleus in their way towards the cerebral cortex. The aim of this work was twofold: (i) to study the mechanisms used by the primary afferents to relay cutaneous information to cuneate cuneolemniscal (CL) and noncuneolemniscal (nCL) cells, and (ii) to determine the intracuneate mechanisms leading to the elaboration of the output signal by CL cells. Extracellular recordings combined with microiontophoresis demonstrated that the primary afferent cutaneous information is communicated to CL and nCL cells through AMPA, NMDA and kainate receptors. These receptors were sequentially activated: AMPA receptors participated mainly during the initial phase of the response, whereas kainate- and NMDA-mediated activity predominated during a later phase. The involvement of NMDA receptors was confirmed by in vivo intracellular recordings. The cutaneous-evoked activation of CL cells was decreased by GABA and increased by glycine acting at a strychnine-sensitive site, indicating that glycine indirectly affects CL cells. Two subgroups of nCL cells were distinguished based on their sensitivity to iontophoretic ejection of glycine and strychnine. Overall, the results support a model whereby the primary afferent cutaneous input induces a centre-surround antagonism in the cuneate nucleus by activating (via AMPA, NMDA and kainate receptors) and disinhibiting (via serial glycinergic-GABAergic interactions) a population of CL cells with overlapped receptive fields that at the same time inhibit (via GABAergic cells) other neighbouring CL cells with different receptive fields.

[Reticulocyte response after immediate withdrawal of recombinant human erythropoietin in chronic hemodialysis patients]

The sudden interruption of recombinant human erythropoietin (rHuEPO) in end-stage renal disease (ESRD) patients leads to rapid anemization. The mechanisms of this phenomenon are, however, insufficiently understood. The present study examined the response to immediate rHuEPO withdrawal in dialysis patients.

METHODS

10 chronic hemodialysis (HD) patients regularly receiving rHuEPO were studied. rHuEPO was stopped and reinitiated after 7 days. Reticulocyte profile, haemoglobin and haematocrit were measured at 0, 7 and 15 days. As a complementary study, and with the purpose of analyzying whether uremia was a relevant factor, 10 non-uremic male Wistar rats were treated with rHuEPO. After two weeks, rHuEPO was withdrawn in 5 animals, and continued for 7 additional days in the remainder. The same variables than in the human study were determined.

RESULTS

Changes in reticulocyte subtypes from baseline to day 7 were: total 18.2 +/- 0.9 vs 14.3 +/- 1.8% (p < 0.06); high-fluorescence (HFR): 2.6 +/- 0.4 vs 0.75 +/- 0.2 (p < 0.001); medium-fluorescence (MFR): 13.0 +/- 1.1 vs 6.6 +/- 0.9% (p < 0.02); and low-fluorescence (LFR): 84.2 +/- 1.4 vs 92.7 +/- 1% (p NS). The baseline pattern was recovered upon 7 days of rHuEPO reinitiation (p NS). Mean hemoglobin and hematocrit decreased by day 14 (p < 0.02) in spite of rHuEPO reinitiation at day 7. In non-uremic rats, changes were similar to that in the ESRD patients.

CONCLUSION

rHuEPO induces changes in the reticulocyte pattern, consisting in a reduction of immature reticulocytes. These changes appear to be independent of the presence of uremia. Accordingly, complete rHuEPO withdrawal in HD patients will cause a rapidly-developing anaemia due to an alteration in the reticulocyte maturation series; therefore, sudden rHuEPO interruption should be avoided whenever is possible. As a collateral application, the specific changes described herein have potential use for detecting illegal administration of rHuEPO.

New corticocuneate cellular mechanisms underlying the modulation of cutaneous ascending transmission in anesthetized cats

The ascending cutaneous transmission through the middle cuneate nucleus is subject to cortico-feedback modulation. This work studied the intracuneate cellular mechanisms underlying the corticocuneate influence. Single unit extracellular records combined with iontophoresis showed that the corticocuneate input activates cuneo-lemniscal (CL) and noncuneo-lemniscal (nCL) cells via N-methyl-D-aspartate (NMDA) and non-NMDA receptors as shown by the decrease of the cortical-induced activation on ejection of CNQX and APV, either alone or in combination. These results were confirmed by in vivo intracellular recordings. Two subgroups of nCL cells were distinguished according to their sensitivity to iontophoretic ejection of glycine and its antagonist, strychnine. Finally, the corticalevoked activation of CL cells was decreased by GABA and increased by glycine acting at a strychnine-sensitive site, indicating that glycine indirectly affects the cuneo-lemniscal transmission. A model is proposed whereby the cortex influences CL cells through three different mechanisms, producing 1) activation via non-NMDA and NMDA receptors, 2) inhibition through GABAergic nCLs, and 3) disinhibition via serial glycinergic-GABAergic nCL cells. These corticocuneate feedback effects serve to potentiate the activity of CL cells topographically aligned through direct activation and disinhibition, while inhibiting, via GABAergic cells, other CL neurons not topographically aligned.

Are beta-sheet breaker peptides dissolving the therapeutic problem of Alzheimer's disease?

Alzheimer's disease (AD) is a neurodegenerative disorder for which there is no cure or effective treatment. One of the major neuropathological signatures of AD is the deposition of amyloid plaques in the brain of affected people. Although the role of these structures in the pathogenesis of the disease is not fully understood, recent findings have provided evidence that amyloid may be a key player in the disease. Therefore, preventing and reversing cerebral amyloid deposition have become an attractive therapeutic strategy for AD. We have engineered synthetic beta-sheet breaker peptides to bind soluble amyloid peptide and prevent and reverse its conversion to the beta-sheet rich aggregated structure, precursor of the amyloid plaques. Results in vitro, in cell culture and in vivo suggest that beta-sheet breaker peptides might be candidates for an AD-therapy focused to reduce amyloid deposition.

Protein misfolding and disease: the case of prion disorders

Recent findings strongly support the hypothesis that diverse human disorders, including the most common neurodegenerative diseases, arise from misfolding and aggregation of an underlying protein. Despite the good evidence for the involvement of protein misfolding in disease pathogenesis, the mechanism by which protein conformational changes participate in the disease is still unclear. Among the best-studied diseases of this group are the transmissible spongiform encephalopathies or prion-related disorders, in which misfolding of the normal prion protein plays a key role in the disease. In this article we review recent data on the link between prion protein misfolding and the pathogensis of spongiform encephalopathies.

The lemniscal-cuneate recurrent excitation is suppressed by strychnine and enhanced by GABAA antagonists in the anaesthetized cat

In the somatosensory system, cuneolemniscal (CL) cells fire high frequency doublets of spikes facilitating the transmission of sensory information to diencephalic target cells. We studied how lemniscal feedback affects ascending transmission of cutaneous neurons of the middle cuneate nucleus. Electrical stimulation of the contralateral medial lemniscus and of the skin at sites evoking responses with minimal threshold induced recurrent activation of CL cells at a latency of 1-3.5 ms. The lemniscal feedback activation was suppressed by increasing the stimulating intensity at the same sites, suggesting recurrent-mediated lateral inhibition. The glycine antagonist strychnine blocked the recurrent excitatory responses while GABAA antagonists uncovered those obscured by stronger stimulation. CL cells sharing a common receptive field (RF) potentiate one another by recurrent activation and disinhibition, the disinhibition being produced by serial interactions between glycinergic and GABAergic interneurons. Conversely, CL cells with different RFs inhibit each other through recurrent GABA-mediated inhibition. The lemniscal feedback would thus enhance the surround antagonism of a centre response by increasing the spatial resolution and the transmission of weak signals.

[Asymptomatic bacteriuria in type 2 diabetics women ]

BACKGROUND

Urinary tract infection (UTI) is frequent among diabetics, especially women. It may be preceded by asymptomatic bacteriuria.

AIM

To study the frequency of asymptomatic bacteriuria in type 2 diabetic women.

PATIENTS AND METHODS

Fifty women with type 2 diabetes and 50 non diabetic women were studied. In aseptic conditions, morning midstream urine specimens were obtained for microbiological analysis. The test was repeated in similar conditions during consecutive days. Urine samples were cultured in blood agar, Mac Conkey agar and CPS ID 2. Colony forming units were counted. Asymptomatic bacteriuria was defined as the presence of 100,000 or more colony forming units per ml. Leukocyturia was also quantified.

RESULTS

There was microbial growth in 40% of samples from diabetic women and 6% of samples from controls (p < 0.01). Asymptomatic bacteriuria was present in 32% of diabetics and 4% of controls (p < 0.01). E Coli was the most frequently isolated strain, in 55% of patients and 100% of controls. Klebsiella pneumoniae was isolated in 10% of diabetics, coagulase negative Staphylococcus in 10%, Enterococcus spp in 10% and Pseudomonas aeruginosa in 5%. Leukocyturia of more than 10 cells per field, was present in 80% of diabetic women with positive culture. Women with positive cultures had a longer lasting diabetes than those with negative cultures. There was no association between urine microbiological results and glycosilated hemoglobin, fasting blood glucose, chronic complications of diabetes and treatment received.

CONCLUSIONS

This study shows a high prevalence of asymptomatic bacteriuria among diabetic women.

Altering prion replication for therapy and diagnosis of transmissible spongiform encephalopathies

Transmissible spongiform encephalopathies, also known as prion-related diseases, are a group of fatal neurodegenerative disorders associated with the misfolding of the prion protein. In this article, the potential use of the principles of prion replication to develop novel therapeutic and diagnostic strategies for these devastating diseases are described.

Biochemical and structural studies of the prion protein polymorphism

A hallmark event in transmissible spongiform encephalopathies is the conversion of the physiological prion protein into the disease-associated isoform. A natural polymorphism at codon 129 of the human prion gene, resulting in either methionine or valine, has profound influence on susceptibility and phenotypic expression of the disease in humans. In this study, we investigated the local propensity of synthetic peptides, corresponding to the region of the polymorphism and containing either methionine or valine, to adopt a beta-sheet-rich structure similar to the pathological protein. Circular dichroism studies showed that the methionine-containing peptide has a greater propensity to adopt a beta-sheet conformation in a variety of experimental conditions. The higher beta-sheet tendency of this peptide was also associated with an increased ability to aggregate into amyloid-like fibrils. These results suggest that methionine at position 129 of the prion protein increases its susceptibility to switch to the abnormal conformation, in comparison with the presence of valine at the same position.

Fluorescence in situ hybridization study of TEL/AML1 fusion and other abnormalities involving TEL and AML1 genes. Correlation with cytogenetic findings and prognostic value in children with acute lymphocytic leukemia

BACKGROUND AND OBJECTIVES

The TEL/AML1 fusion is the most common genetic abnormality found in childhood acute lymphoblastic leukemias (ALL). Although it is very difficult to identify by conventional cytogenetic techniques it can be readily detected using fluorescence in situ hybridization (FISH). We carried out cytogenetic and FISH studies on 42 children with ALL in order to know the frequency of this translocation in our population, the incidence of TEL and/or AML1 gene alterations, and their correlation with clinical evolution and prognosis. In addition, we performed reverse transcription polymerase chain reaction (RT-PCR) in some cases, confirming the feasibility of FISH techniques in the detection of this translocation.

DESIGN AND METHODS

Bone marrow samples were obtained from 42 childhood ALL patients. The copy number of AML1 and TEL genes were studied using fluorescent in situ hybridization with a dual color DNA probe specific for the AML1 and TEL genes.

RESULTS

We found a frequency of TEL/AML1 fusion of 17% in our sample. Double TEL/AML1 fusion, lack of TEL signal and extra AML1 signals were frequent additional FISH abnormalities. Duplication of a chromosomal complement, deletion of chromosome 12p arm, and polysomies of chromosome 21 are plausible explanations for these additional FISH findings. However, a relatively high proportion of our cases (9.5%) presented specific amplification of AML1. A statistically significant difference in prognosis was found between patients with and without these additional AML1 or TEL FISH alterations (p<0.02), which could be related to the presence of specific karyotypes.

INTERPRETATIONS AND CONCLUSIONS

The frequency of TEL/AML1 fusion is similar to that found in other populations (17%). We found that FISH analysis of AML and TEL is related to the evolution of the disease. The absence of alterations in these genes revealed by FISH could be indicative of bad prognosis, while the presence of alterations is related to a good evolution. Our results suggest that interphase FISH analysis to search for alterations in AML and TEL genes could be extremely useful for complementing cytogenetic studies and for providing additional information about the possible outcome of the disease in patients with ALL.

Alloxan decreases intracellular potassium content of the isolated frog skin epithelium

Alloxan has been widely used to provoke diabetes mellitus. This compound induces necrosis of the beta-pancreatic cells and the renal tubules. However, the mechanism of this action has not been fully established. There is some evidence that this drug may act by an alteration of several ionic transport mechanisms. Nevertheless, there is scant information on the effect of alloxan on these ionic transport mechanisms of the membrane in epithelial cells. We reported that this drug induces a decrease in sodium transport in the frog skin. In order to obtain information about the mechanism involved in the sodium transport diminution provoked by alloxan, in this study the function of Na+-K+ ATPase enzyme on transepithelial sodium transport altered by alloxan is explored. We measured changes in the short circuit current and in the intracellular content of sodium and potassium under conditions of maximally stimulated enzyme activity. Short circuit current was not modified by the treatment with alloxan during the period of highest activity of the enzyme, suggesting a site of action independent of this ATPase. Cell potassium was reduced in alloxan-treated epithelia, without significant changes in Na+ content. This finding points out the existence of an alteration induced by alloxan of some modulator mechanisms of the intracellular K+ concentration. The treatment of the frog skin with cesium chloride, a K+ channel blocker, prevented the decrease of Na+ transport produced by alloxan. This result suggests an action of this diabetogenic drug on the K+ channels of the frog skin epithelium.

[The cerebral cortex modulates the cutaneous transmission through the dorsal column nuclei]

INTRODUCTION

The mechanisms used by the cerebral cortex to modulate the cutaneous information at prethalamic level have been scarcely studied. This article reviews experimental evidence leading to a better understanding of this issue at the level of the cuneate nucleus (Burdach nucleus).

DEVELOPMENT

The primary afferents and the corticocuneate fibers make synaptic contact with cuneothalamic neurons and with inhibitory interneurons in the middle cuneate nucleus. By stimulating the skin at different places while recording the cuneothalamic intracellular activity in anaesthetized animals with the cortex intact, with the cortex pharmacologically inactivated, or in absence of a cerebral cortex it was possible to ascertain the functional role of the corticocuneate fibers. The primary afferents activated by stimulating a particular zone of the skin induce monosynaptic excitation on a group of cuneothalamic cells at the same time at which inhibit, through intranuclear interneurons, neighboring cuneothalamic cells with unmatched receptive fields. Similarly, the corticocuneate cells receiving information from the stimulated skin further increase the excitation of the cuneothalamic neurons with matched receptive fields while inhibiting others with unmatched fields. The cortex exaggerates an excited center surrounded by an inhibited periphery thus increasing the tactile discrimination both spatially and temporally which is essential for exploratory and manipulative purposes.

Sensitive detection of pathological prion protein by cyclic amplification of protein misfolding

Prions are the infectious agents responsible for transmissible spongiform encephalopathies. The principal component of prions is the glycoprotein PrP(Sc), which is a conformationally modified isoform of a normal cell-surface protein called PrP(C) (ref. 1). During the time between infection and the appearance of the clinical symptoms, minute amounts of PrP(Sc) replicate by conversion of host PrP(C), generating large amounts of PrP(Sc) aggregates in the brains of diseased individuals. We aimed to reproduce this event in vitro. Here we report a procedure involving cyclic amplification of protein misfolding that allows a rapid conversion of large excess PrP(C) into a protease-resistant, PrP(Sc)-like form in the presence of minute quantities of PrP(Sc) template. In this procedure, conceptually analogous to polymerase chain reaction cycling, aggregates formed when PrP(Sc) is incubated with PrP(C) are disrupted by sonication to generate multiple smaller units for the continued formation of new PrP(Sc). After cyclic amplification more than 97% of the protease-resistant PrP present in the sample corresponds to newly converted protein. The method could be applied to diagnose the presence of currently undetectable prion infectious agent in tissues and biological fluids, and may provide a unique opportunity to determine whether PrP(Sc) replication results in the generation of infectivity in vitro.

Protein misfolding and disease; protein refolding and therapy

Diverse human disorders, including several neurodegenerative diseases and systemic amyloidosis, are thought to arise from the misfolding and aggregation of an underlying protein. Recent findings strongly support this hypothesis and have increased our understanding of the molecular mechanism of protein conformational disorders. Many questions are still pending, but the data overall suggest that correction of protein misfolding constitutes a viable therapeutic strategy for conformational diseases.