Which Technical Aspects have an Impact on Perceived Pain during Transperineal Prostate Biopsy? A Prospective Study Involving 445 Cases

To assess the technical aspects determining the perceived pain during prostate biopsy via transperineal access.

Materials and Methods

We conducted prostate biopsy with transperineal access in local anesthesia. Between January 2007 and January 2008, data on prostatic biopsies were prospectively surveyed. The patient was requested to assess perceived pain by means of a Visual Analogue Scale ranging from 0 (no pain) to 10 (unbearable pain). Complications were recorded by telephone interviews 30 days after the biopsy. The histological diagnosis was recorded.

Results

445 prostate biopsies were conducted. The average perceived pain score amounted to 2.60. At univariate analysis, a lower score was recorded in cases where the anesthetic agent was diluted with physiological saline, those in which a single cutaneous access was chosen along the middle line, those in the first bioptic series as compared to the following series and those in which no sampling involved the transition region. However, the multivariate analysis showed that only the single cutaneous access was statistically significant. In those cases, also the rates of delayed perineal pain were significantly lower. The cancer diagnosis rate showed no correlations with the type of cutaneous access.

Conclusions

A single median cutaneous access reduces the pain associated to transperineal prostatic biopsy.

Cardiac remodeling in patients with primary aldosteronism

OBJECTIVE

To evaluate the morpho-functional changes of the myocardium in patients with primary aldosteronism (PA).

DESIGN

An observational study in a university referral center for blood pressure diseases.

PATIENTS

Twenty- three patients with PA, 24 patients with essential hypertension (EH), and 15 normotensive controls (C) underwent conventional echocardiography with integrated backscatter (IBS) and tissue Doppler imaging (TDI) analysis. The corrected IBS (C-IBS) values and the systo-diastolic variation of IBS (CV-IBS) were performed at both interventricular septum and the posterior wall levels. TDI myocardial systolic (Sm), early diastolic (Em), and late diastolic (Am) velocities of both left ventricular walls were also determined.

RESULTS

In PA patients, septal and posterior wall CV-IBS were significantly lower than C (p<0.0001) and EH patients (p<0.001). In EH, CV-IBS was significantly lower than C (p<0.001). Patients with PA exhibited lower Sm, lower Em, and higher Am, and a subsequently reduced Em/Am ratio than C (p<0.001 for all) and EH (p<0.01 for all) at interventricular septum and lateral wall levels. In the latter, Sm, Em, and Em/Am ratio were lower and Am was higher than C (p<0.001 for all). In PA and EH patients, CV-IBS at both septum (r=-0.66, p<0.001) and posterior wall levels (r=-0.67, p<0.001) and Sm peak of both septum (r=-0.52, p<0.001) and lateral wall (r=-0.55, p<0.001) were inversely related to plasma aldosterone.

CONCLUSIONS

Patients with PA showed myocardial wall remodeling characterized by increased myocardial fibrosis and early left ventricular systodiastolic function abnormalities.

Radical Cystectomy for Transitional Cell Carcinoma with Orthotopic Neobladder in Renal Transplant Recipients: Surgical Procedure, Functional and Therapeutic Evaluation

Introduction

Transitional Cell Carcinoma (TCC) shows a high prevalence in renal tranplant recipients, nevertheless urinary reconstruction by way of orthotopic neobladder is rarely reported.

Patients and Methods

Two kidney transplant patients (1 man and 1 woman) affected by TCC underwent radical cystectomy and urinary reconstruction by neobladder according to the “Vescica Ileale Padovana” technique.

Results and Discussion

No patients claimed incontinence or urine retention. The spherical rebuilding assured an adequate bladder capacity and a low endovesical pressure. After 48 months one patient died because of disease progression. The first relapse was detected in ureter two years after cystectomy. The other patient is still alive after 40 months and in good health conditions.

Conclusions

This anecdotal report suggests that the “Vescica Ileale Padovana” technique could be useful in renal transplant recipients with TCC. A possible role of Rapamycin on our results cannot yet be excluded.

Tumor Suppressor Proteins are Differentially Affected in Human Ependymoblastoma and Medulloblastoma Cells Exposed to Nerve Growth Factor

The aim of our study was to investigate the role of nerve growth factor (NGF) on the expression of the p73 protein in human ependymoblastoma (EP) and medulloblastoma (MB) cells. It was found that NGF exposure on MB cells blocks proliferation, as well as on EP cells and induces overexpression of p73. NGF reduces the number of cells and promotes the expression of TrkA of these neoplastic cells. Moreover, NGF plus cisplatin treatment reduces the cytotoxic effect of cisplatin. These observations indicate that NGF by interfering with mechanisms associated with cells proliferation and survival might induce the differentiation event through TrkA pathways.

A phylogenetic approach to detect selection on the target site of the antifouling compound irgarol in tolerant periphyton communities

Using DNA sequence data for phylogenetic assessment of toxicant targets is a new and promising approach to study toxicant-induced selection in communities. Irgarol 1051 is a photosystem (PS) II inhibitor used in antifouling paint. It inhibits photosynthesis through binding to the D1 protein in PS II, which is encoded by the psbA gene found in genomes of chloroplasts, cyanobacteria and cyanophages. psbA mutations that alter the target protein can confer tolerance to PS II inhibitors. We have previously shown that irgarol induces community tolerance in natural marine periphyton communities and suggested a novel tolerance mechanism, involving the amino acid sequence of a turnover-regulating domain of D1, as contributive to this tolerance. Here we use a large number of psbA sequences of known identity to assess the taxonomic affinities of psbA sequences from these differentially tolerant communities, by performing phylogenetic analysis. We show that periphyton communities have high psbA diversity and that this diversity is adversely affected by irgarol. Moreover, we suggest that within tolerant periphyton the novel tolerance mechanism is present among diatoms only, whereas some groups of irgarol-tolerant cyanobacteria seem to have other tolerance mechanisms. However, it proved difficult to identify periphyton psbA haplotypes to the species or genus level, which indicates that the genomic pool of the attached, periphytic life forms is poorly studied and inadequately represented in international sequence databases.

NGF, DCX, and NSE upregulation correlates with severity and outcome of head trauma in children

BACKGROUND

Secondary brain damage after traumatic brain injury (TBI) involves neuroinflammatory mechanisms, mainly dependent on the intracerebral production of specific biomarkers, such as cytokines, neurotrophic factors, and neuron-specific enolase (NSE). NSE is associated with neuronal damage, while neurotrophic factors play a neuroprotective role due to their ability to modulate neuronal precursor biosynthesis, such as doublecortin (DCX). However, the relationships between the expression of these factors and the severity and outcome of TBI are not understood.

METHODS

To determine whether the concentrations of neurotrophic factors (nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], glial-derived neurotrophic factor [GDNF]), DCX, and NSE in the CSF of children with TBI correlate with the severity of brain damage and neurologic outcome, we prospectively collected CSF samples from 32 children at 2 and 48 hours after admission for severe TBI and from 32 matched controls. Severity of TBI was evaluated by Glasgow Coma Scale and neurologic outcome by Glasgow Outcome Score.

RESULTS

Early NGF, DCX, and NSE concentrations correlated significantly with the severity of head injury, whereas no correlation was found for BDNF and GDNF. Furthermore, NGF and DCX upregulation and lower NSE expression were associated with better neurologic outcomes. No significant association was found between BDNF and GDNF expression and outcome.

CONCLUSIONS

Nerve growth factor (NGF), doublecortin (DCX), and neuron-specific enolase concentrations in the CSF are useful markers of brain damage following severe traumatic brain injury (TBI). NGF and DCX upregulation correlates also with better neurologic outcome and could be useful to obtain clinical and prognostic information in children with severe TBI.

High values of Th1 (CXCL10) and Th2 (CCL2) chemokines in patients with psoriatic arthtritis

OBJECTIVE

To evaluate serum levels of CXCL10 and CCL2 in a large series of PsA patients, and to relate chemokines levels to the clinical phenotype of these patients.

METHODS

Serum levels of CXCL10 and CCL2 were measured in 68 PsA patients, and in gender- and age-matched (1:1) controls drawn from the general population.

RESULTS

PsA patients showed significantly (p<0.001) higher mean CXCL10 serum levels than controls (p<0.0001), (269+/-234 vs. 92+/-53 pg/ml; respectively). By defining a high CXCL10 level as a value at least 2 SD above the mean value of the control group (>198 pg/ml), 49% of patients with PsA and 5% of the control subjects had high CXCL10 (p<0.0001; chi-square). A significant inverse correlation was observed between CXCL10 serum levels and disease duration (r= 0.374, p=0.002).Patients with PsA showed significantly higher mean CCL2 serum levels than controls (p<0.001), (512+/-309 vs. 386+/-172, pg/ml; respectively). By defining a high CCL2 level as a value at least 2 SD above the mean value of the control group (>730 pg/ml), 19% of patients with PsA, 2% of the control subjects had high CCL2 (p<0.001; chi-square=22.02).

CONCLUSION

In conclusion, high circulating levels of CXCL10 and CCL2 have been found in PsA patients, with a Th1 immune predominance in the early phase of the disease. A decline of CXCL10 levels has been observed in long lasting PsA, with a significant increase of the CCL2/CXCL10 ratio, suggesting a shift from Th1 to Th2 immune response in long duration PsA.

CXCL10 and CCL2 serum levels in patients with mixed cryoglobulinaemia and hepatitis C

BACKGROUND

No study evaluates serum levels of CXCL10 and CCL2 chemokines in patients with hepatitis C associated mixed cryoglobulinaemia.

AIMS

To measure circulating CXCL10 and CCL2 in cryoglobulinaemic patients.

PATIENTS AND METHODS

Serum CXCL10 and CCL2 were assayed in 70 consecutive cryoglobulinaemic patients, and in 2 control groups (1:1, gender- and age-matched) of healthy (controls), or of chronic hepatitis C subjects without cryoglobulinaemia.

RESULTS

Cryoglobulinaemic patients showed higher CXCL10 serum levels than controls (p<0.0001), or hepatitis C patients (p=0.001) (389 +/- 141, 91 +/- 51, 311 +/- 142 pg/ml, respectively). By defining a "high CXCL10" as a value at least 2 S.D. above the mean value of the control group (>193 pg/ml), 79% of cryoglobulinaemic patients, 5% of the controls and 69% of hepatitis C patients had high CXCL10 (p<0.0001). CXCL10 levels were (p<0.01) increased in cryoglobulinaemic patients with active vasculitis, with respect to those without (445+/-108, 339 +/- 161 pg/ml, respectively). Cryoglobulinaemic patients showed significantly higher CCL2 serum level than controls (p<0.01), but not than hepatitis C patients (541 +/- 493, 387 +/- 173 and 451 +/- 281 pg/ml, respectively).

CONCLUSION

Our study first demonstrates high serum levels of CXCL10 and CCL2 chemokines in cryoglobulinaemic patients. Circulating CXCL10 is higher overall in cryoglobulinaemic patients with active vasculitis, suggesting a prevalence of the Th1 immune response in this phase.

Aminolevulinic Acid in Diagnosis and Treatment of Bladder Urothelial Carcinoma

It might be difficult to diagnose either bladder's flat lesions, such as CIS, or small papillary lesions using white-light endoscopy.

Neoplastic cells can be differentiate from the normal bladder mucous membrane by using Hexyl-ALA. Hexyl aminolevulinate produces protoporphyrin's overstock inside cancer cells causing a clearly visible red fluorescence when these are hit by a predetermined wavelenght light. The purpose of this study is to evaluate effectiveness of PDD (photodynamic diagnosis) by using Hexyl-ALA to identify and treat bladder's surface cancer.

This study considers 39 patients (33 men and 6 women) from November 2008 to January 2009. On these patients were taken, previous filling of their bladders with hexyl aminolevulinate solution, 106 hystological samples (among these: 38 were first step diagnosis, 15 were a second look and 53 were taken for a relapse suspect). The 72.6% of these samples (77) were positive for cancer, while the 27,4% (29) was normal.

Of those 77 samples, 30 were discovered to be positive exclusively by using PDD and include CIS (66.6%), Ta G1–2 (20%), reactive hyperplasia (3.3%) and incipient papillary neoplasia (10%). (Anatomopathologist described the last two lesions as partial nuclear alterations not fullfilling the criteria of pathology). This research proves that, among other diagnostic methods, photodynamic diagnosis has a higher sensibility, although the specificity is lower.

Serum Th1 (CXCL10) and Th2 (CCL2) chemokine levels in children with newly diagnosed Type 1 diabetes: a longitudinal study

AIMS

Cell-mediated immunity and pro-inflammatory cytokines are implicated in the pathogenesis of Type 1 diabetes. The aim of this study was to investigate whether circulating chemokines involved in T-helper 1 (CXCL10) and T-helper 2 (CCL2) autoimmunity are increased in children with Type 1 diabetes at onset and follow-up.

METHODS

Serum CXCL10 and CCL2 were measured in 96 children with newly diagnosed Type 1 diabetes, 59 age-matched first-degree relatives of diabetic children and 40 age-matched non-diabetic children with no family history of diabetes. In the diabetic children, an additional serum sample was obtained a median of 16 months after diagnosis.

RESULTS

Serum CXCL10 levels were significantly higher in Type 1 children than in relatives or control children (P < 0.001); 44.7% of patients had a serum CXCL10 level >or= 2 standard deviation above the mean value of the control group vs. 3.4% of relatives (P < 0.0001). In contrast, serum CCL2 levels were similar in patients, relatives and control subjects. In the Type 1 diabetic patients at follow-up, CXCL10 was significantly reduced vs. baseline (P = 0.01), while CCL2 did not change.

CONCLUSIONS

In children with newly diagnosed Type 1 diabetes, raised serum CXCL10 and normal CCL2 concentrations signal a predominant T-helper 1-driven autoimmune process, which shifts toward T-helper 2 immunity over the first 1-2 years from diagnosis.

Effect of macrophage depletion on viral DNA rebound following antiretroviral therapy in a murine model of AIDS (MAIDS)

In the attempt to eradicate HIV-1 infection, a strategy to eliminate macrophages, one of the most important cellular reservoirs in sustaining virus replication during HAART, could be of great benefit in the suppression of viral rebound. Aware of the ability of clodronate to cause macrophage depletion, the effect of the administration of clodronate encapsulated in erythrocytes on disease progression and on viral rebound was evaluated in a murine model of AIDS (MAIDS). One group of LP-BM5 retroviral complex-infected C57BL/6 mice received oral administrations of azidothymidine and dideoxyinosine daily for 12 weeks; two other groups received in addition, either clodronate-loaded erythrocytes or free clodronate at 7-10 day intervals. At the end of the treatment, the three groups maintained parameters characterizing disease progression similar to those of uninfected mice and showed a significantly lower level of BM5d DNA than infected mice in all organs and cells tested. To assess the viral rebound, some animals were left for an additional 4 month period without any treatment. After this time, the BM5d DNA content in blood leukocytes increased in all groups, but the group having received clodronate-loaded erythrocytes, in addition to transcriptase inhibitors, showed a significant delay in viral rebound.

[Correlation of a quantitative videocapillaroscopic score with the development of digital skin ulcers in scleroderma patients]

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of the skin and visceral organs. The microangiopathy is early detectable in the course of the disease by nailfold videocapillaroscopy (NVC), a non-invasive technique with a high diagnostic value.

OBJECTIVE

Aim of our study was to evaluate the feasibility of a quantitative score and its correlation with the digital skin ulcers, which frequently complicate SSc microangiopathy.

METHODS

We retrospectively analysed the NVC of 65 SSc patients, performed by 200x videocapillaroscopy connected to image analyse software (Videocap; DS MediGroup, Milan, Italy). The analysis of NVC images included: total number of capillaries in the distal row (N), maximum diameter (D) and number of giant capillaries (M), M/N ratio and percentage of M, presence/absence of micro-haemorrhages and tortuosity.

RESULTS

21/65 SSc patients experienced digital ulcers within three months after the NVC examination. The N, D, M/N, and percentage of M significantly correlated with the appearance of ischemic ulcers. A multiple regression analysis showed a statistically significant correlation for N, M/N and D, while sensitivity and specificity of these parameters were unsatisfactory. A capillaroscopic score, according to the formula D x M/N2, showed a high specificity and sensibility (93.2% and 85.7% respectively; area under ROC curve: 0.918) to predict the appearance of digital ulcers.

CONCLUSIONS

This capillaroscopic score may represent a feasible and simple tool in SSc patients' assessment. The routinely use of this parameter might permit to recognize and to preventively treat SSc patients at high risk to develop digital ulcers.

Renal cell carcinoma associated with incidental presentation of renal artery aneurysm: surgical management

The Renal Artery Aneurysm (RAA) is a relatively uncommon vascular lesion. A renal artery disease coexisting in patients with Renal Cell Carcinoma (RCC) is an even more infrequent clinical presentation. We reported on the treatment of a rare case of incidentally intraoperative renal artery aneurysm discovered during a nephron-sparing surgery for RCC. After the surgery the patient did not need hypertension therapy any longer. This event is well-known, in fact a number of possible contributions to a renin-mediated hypertension management has been postulated.

[Renal cell carcinoma associated with incidental presentation of renal artery aneurysm: surgical management]

The Renal Artery Aneurysm (RAA) is a relatively uncommon vascular lesion. A renal artery disease coexisting in patients with Renal Cell Carcinoma (RCC) is an even more infrequent clinical presentation. We reported on the treatment of a rare case of incidentally intraoperative renal artery aneurysm discovered during a nephron-sparing surgery for RCC. After the surgery the patient did not need hypertension therapy any longer. This event is well-known, in fact a number of possible contributions to a renin-mediated hypertension management has been postulated.

A 7-case anatomopathology revision in the presence of renal relapse after conservative therapy: implications on surgical technique

Anatomopathology revision of the cases which underwent second surgery because of a renal neoplasm relapsing after conservative surgery in order to find possible relations with the surgical technique.

Materials and Methods.

At our institution, Nephron-sparing surgery (NSS) is currently indicated as elective technique for neoplasms smaller than 4cm in diameter. The technique involves the removal of the neoplasm with a margin of healthy parenchyma and with the perilesional fat. The patients are monitored with a first CT check after 4 months and then with ultrasound/CT checks every 6 months in the first 2 years and then once a year. In the present study we analyze the records of the cases in the period 1994–2005 undergoing a second operation for a renal tumor relapsing in the operated kidney after NSS. All specimens were reviewed by a single experienced uro-pathologist, who determined the size of the surgical margins and the relations between the seat of recidivism and the seat of the preceding enucleoresection.

Results.

Seven cases with renal relapse were found out of 267 undergoing conservative surgery in the same period (incidence: 2.6%). The diagnosis had always been made lacking any other disease localizations at a complete re-staging; the average relapse latency was 19.4 months (8–46 months). In 5 cases the second tumor was found in the seat of the previous NSS: for these cases the minimum margin of the enucleoresection was lower than 3mm (median minimum margin: 1.6 mm). Differently, in the remaining 2 cases, both with a wider surgical margin (median minimum margin: 12.0 mm), the seat of the first and that of the second neoplasm were distant. In particular, in one case a multifocal relapse with a spread microvascular embolization was found, while in the other the two neoplasms showed a different histotype.

Discussion and Conclusions.

In the 5 cases with a little resection margin and relapsing tumor in the seat of the enucleoresection, the persistence of a peritumoral microscopic neoplastic disease can be assumed. In the other 2 cases showing a wider surgical margin the relapse can be attributed to the widespread microscopic multifocality in one case, and to the development of a second de novo neoplasm in the other case. The extension of the surgical margin seems then to have played a role in determining a relapse in the seat of enucleoresection.

[A 7-case anatomopathology revision in the presence of renal relapse after conservative therapy: implications on surgical technique]

Anatomopathology revision of the cases which underwent second surgery because of a renal neoplasm relapsing after conservative surgery, in order to find possible relations with the surgical technique. MATERIALS AND METHODS. At our institution, Nephron-sparing surgery (NSS) is currently indicated as elective technique for neoplasms smaller than 4cm in diameter. The technique involves the removal of the neoplasm with a margin of healthy parenchyma and with the perilesional fat. The patients are monitored with a first CT check after 4 months and then with ultrasound/CT checks every 6 months in the first 2 years and then once a year. In the present study we analyze the records of the cases in the period 1994-2005 undergoing a second operation for a renal tumor relapsing in the operated kidney after NSS. All specimens were reviewed by a single experienced uro-pathologist, who determined the size of the surgical margins and the relations between the seat of recidivism and the seat of the preceding enucleoresection. RESULTS. Seven cases with renal relapse were found out of 267 undergoing conservative surgery in the same period (incidence: 2.6%). The diagnosis had always been made lacking any other disease localizations at a complete re-staging; the average relapse latency was 19.4 months (8-46 months). In 5 cases the second tumor was found in the seat of the previous NSS: for these cases the minimum margin of the enucleoresection was lower than 3mm (median minimum margin: 1.6 mm). Differently, in the remaining 2 cases, both with a wider surgical margin (median minimum margin: 12.0 mm), the seat of the first and that of the second neoplasm were distant. In particular, in one case a multifocal relapse with a spread microvascular embolization was found, while in the other the two neoplasms showed a different histotype. DISCUSSION AND CONCLUSIONS. In the 5 cases with a little resection margin and relapsing tumor in the seat of the enucleoresection, the persistence of a peritumoral microscopic neoplastic disease can be assumed. In the other 2 cases showing a wider surgical margin the relapse can be attributed to the widespread microscopic multifocality in one case, and to the development of a second de novo neoplasm in the other case. The extension of the surgical margin seems then to have played a role in determining a relapse in the seat of enucleoresection.

Cancer in kidney transplantation

Cancer in the transplanted kidney is rare, and its clinical and surgical management can be controversial. We report 3 cases of cancer in renal transplantation (1 case of renal cell carcinoma and 2 cases of transitional cell carcinoma) and their treatment. Our data and those reported in the literature suggest that these cancers can be treated like a neoplasm in the general population. However, a higher number of cases and longer follow-up periods are necessary to confirm our findings.

Thyroid fine needle aspiration: how to improve clinicians' confidence and performance with the technique

Studies from single institutions report an acceptable accuracy rate for thyroid fine needle aspiration (FNA). However, FNA accuracy is much lower in many other centers in Europe and the USA and large multicenter studies indicate that the clinicians' confidence in the FNA technique remains low. One explanation for this is that there is an excess of inadequate and indeterminate findings for a follicular nodule at FNA cytology. In a University Hospital with large and qualified experience on thyroid nodule diagnosis, a review of 320 slides with an FNA diagnosis of indeterminate follicular nodule from different minor Italian Hospitals led to a different diagnosis in 61%. Since ancillary thyroid imaging may be overutilized and only a few authors report a proportion of excised nodules lower than 10%, we suspect that use of the FNA procedure is suboptimal. Several techniques are reported to improve the performance of thyroid FNA. Among these are tumor markers and large needle aspiration biopsy (LNAB). Immunodetection of the tumor marker galectin-3 has been evaluated by large multinational studies. Analysis of LNAB specimens reduces the number of inadequate FNA findings, improves the diagnostic determination of indeterminate follicular FNA findings and represents a better substrate for the determination of galectin-3. Therefore, we propose that clinical practice guidelines reflect these adjuvant techniques to thyroid FNA in order to improve selection criteria for thyroid nodule surgery.

Neurotrophic factor expression in newborns with myelomeningocele: preliminary data

BACKGROUND

Neurotrophic factors play a crucial role in the stimulation of sprouting, synaptic plasticity and reorganization after spinal cord damage. The aim of this study was to investigate the expression of some neurotrophic factors [brain derived neurotrophic factor (BDNF), glial derived neurotrophic factor (GDNF), and nerve growth factor (NGF)] in the cerebrospinal fluid (CSF) of newborns with myelomeningocele (MMC) and to determine their correlations with this malformation.

METHODS

To measure the expression of BDNF, GDNF, and NGF, we collected CSF samples of six newborns during the neurosurgical operation to correct the open MMC and of 10 matched controls. Endogenous neurotrophic factor levels were quantified using a two-site immuno-enzymatic assay. The statistical analysis was performed using the Mann-Whitney two-tailed two-sample test.

FINDINGS

In the CSF of patients analysis of neurotrophic factor expression showed a significant increase of BDNF, GDNF, and NGF compared to the mean level of the control group (445.8+/-82.3, 86.5+/-2.6, and 59.9+/-6.2 pg/mL, respectively, respect to 10.2+/-5.9, 19.9+/-11.3, and 15.3+/-2.6 pg/mL) (p<0.001).

INTERPRETATION

Our study shows an over-expression of neurotrophic factors in the CSF of newborns with MMC. This neurotrophin up-regulation may stimulate axonal sprouting and synaptic reorganization of the damaged neural cells at the site of spinal cord lesion. The neurotrophic factor up-regulation may represent a particularly important biochemical markers of spinal cord damage and might be associated with the severity of spine injury in MMC patients.

Surgery for renal carcinoma metastases

During the last few years, the increasing use of diagnostic imaging (especially ultrasound) has allowed a remarkable rise in the detection of asymptomatic, early-stage renal neoplasms, possibly treatable by radical surgery. Renal cell carcinoma, however, is still the renal neoplastic condition with the highest mortality rate, due in most cases to the presence of distal metastases.

Because of a lack of agreement on an efficient systemic therapeutic approach, surgery is generally considered to be the most suitable option to remove metastases: it is technically easy to perform, it can increase survival and the patient's psychological compliance, though metastasectomy is unlikely to cure the metastatic patient.

In our experience, we studied 1475 patients who underwent surgery for renal cell carcinoma from 1983 on. 304 (20%) developed a metastasis; 4 subjects only (5.4%) out of the 74 having multiple metastatic anatomical sites were long-surviving. 39 subjects (16.9%) out of the 230 having single-site metastases are currently disease-free (mean follow-up: 80 months from diagnosis): 33 out of the 111 patients who underwent metastasectomy, 4 out of the 57 who received a medical therapy, 1 out of the 14 being administered radiotherapy, and 1 out of the 48 who were cared under palliative purposes only.

Therefore we concluded that, in case of single-site (lung or adrenal) metastases, surgery is the most suitable and advisable therapeutic approach, being the only option able to achieve survival even for a small amount of patients.

New biologic drugs are currently under investigation, which can interfere with tumor proliferation and angiogenesis: the study results are still preliminary, nevertheless these drugs open the way to a multimodal medical option of treatment for metastatic renal cell carcinoma.

HCV infection: pathogenesis, clinical manifestations and therapy

Chronic hepatitis C virus (HCV) infection is a worldwide public health problem with a global prevalence of 2-3%. It is believed that about 170 million people are currently infected (about 3% of the world's population), and a further 3-4 million are infected each year. HCV is the main reason for liver transplantation in the developed world, and the main cause of liver-related morbidity and mortality in a number of countries, including Italy. It is not only a frequent cause of chronic liver diseases such as hepatitis, cirrhosis and hepatocellular carcinoma, but is also involved in the pathogenesis of various autoimmune and rheumatic disorders (arthritis, vasculitis, sicca syndrome, porphyria cutanea tarda, lichen planus, nephropathies, thyroid diseases, and lung fibrosis), as well as in the development of B-cell lymphoproliferative diseases. Furthermore, patients suffering from C hepatitis tend to produce rheumatoid factor, cryoglobulins and a large series of autoantibodies (ANA, anti-SSA/SSB, SAM, ATG, aCL). The use of glucocorticoids or immuno-suppressant agents in HCV infected individuals, which are needed to treat autoimmune and rheumatic disorders, leads to a risk of worsening the clinical outcome of HCV. Under these conditions, the viral infection often needs to be treated with antiviral agents, mainly pegylated interferon combined with ribavirin. However, cyclosporine A seems to be safe and effective in patients with autoimmune disease (AD) and concomitant chronic HCV infection as is documented by the reduction in viremia and transaminases, particularly in patients with high baseline levels. Finally, HCV is the main trigger of mixed cryoglobulinemia. An attempt at viral eradication is therefore indicated in most patients, and is particularly effective in the case of mild or moderate manifestations. In severe cases, rituximab is an apparently safe and effective alternative to conventional immunosuppression and, specifically, it controls B-cell proliferation.

[Surgery for renal carcinoma metastases]

During the last few years, the increasing use of diagnostic imaging (especially ultrasound) has allowed a remarkable rise in the detection of asymptomatic, early-stage renal neoplasms, possibly treatable by radical surgery. Renal cell carcinoma, however, is still the renal neoplastic condition with the highest mortality rate, due in most cases to the presence of distal metastases. Because of a lack of agreement on an efficient systemic therapeutic approach, surgery is generally considered to be the most suitable option to remove metastases: it is technically easy to perform, it can increase survival and the patient's psychological compliance, though metastasectomy is unlikely to cure the metastatic patient. In our experience, we studied 1475 patients who underwent surgery for renal cell carcinoma from 1983 on. 304 (20%) developed a metastasis; 4 subjects only (5.4%) out of the 74 having multiple metastatic anatomical sites were long-surviving. 39 subjects (16.9%) out of the 230 having single-site metastases are currently disease-free (mean follow-up: 80 months from diagnosis): 33 out of the 111 patients who underwent metastasectomy, 4 out of the 57 who received a medical therapy, 1 out of the 14 being administered radiotherapy, and 1 out of the 48 who were cared under palliative purposes only. Therefore we concluded that, in case of single-site (lung or adrenal) metastases, surgery is the most suitable and advisable therapeutic approach, being the only option able to achieve survival even for a small amount of patients. New biologic drugs are currently under investigation, which can interfere with tumor proliferation and angiogenesis: the study results are still preliminary, nevertheless these drugs open the way to a multimodal medical option of treatment for metastatic renal cell carcinoma.

Percutaneous large-needle aspiration biopsy histology of palpable thyroid nodules: technical and diagnostic performance

AIM

To report original and review existing data on safety and performance of large-needle aspiration biopsy (LNAB) histology in the preoperative selection of palpable thyroid nodule.

METHODS AND RESULTS

The English literature and original data were reviewed or analysed. The literature on LNAB of thyroid nodules did not report any complications. A study on needle dimensions has explained why LNAB obtains more tissue than fine-needle aspiration (FNA) and is safe. LNAB histology has higher specificity than FNA cytology and markedly reduces the number of inadequate and indeterminate FNA findings. A comparison of 150 FNA-derived cell blocks with 200 LNAB-derived histological blocks after galectin-3 determination in a large nationwide (Italian) study has shown that one to two sections in 10% of the FNA cell blocks and at least five sections in 90% of the LNAB blocks were available for further determinations of thyroid tumour markers.

CONCLUSION

LNAB merits further consideration for the preoperative selection of thyroid nodules.

HCV-related autoimmune and neoplastic disorders: the HCV syndrome

Hepatitis C virus (HCV) chronic infection may be associated with a great number of both hepatic and extrahepatic manifestations. HCV lymphotropism is responsible for poly-oligoclonal B-lymphocyte expansion, which is the common underlying alteration in a significant percentage of HCV-infected individuals. The consequent production of different autoantibodies and immune-complexes, including cryoglobulins, may lead to organ- and non-organ-specific immunological alterations. Mixed cryoglobulinemia, a small-vessel systemic vasculitis, is characterized by the coexistence of autoimmune and lymphoproliferative alterations; therefore, it represents the prototype of HCV-associated disorders. Moreover, HCV shows an oncogenic potential; several studies support its pathogenetic link with some malignancies, mainly hepatocellular carcinoma and B-cell lymphomas. On the whole, HCV-related disorders present a heterogeneous geographical distribution, suggesting a role of other important genetic and/or environmental cofactors. While the majority of HCV-infected individuals is asymptomatic or may develop only liver manifestations, a significant percentage of them may develop a variable combination of autoimmune lymphoproliferative disorders. The resulting multiform clinico-pathological condition can be termed HCV syndrome. The natural history of HCV syndrome is the expression of multifactorial and multistep pathogenetic process, which usually proceeds from mild, often isolated manifestations to systemic immune-mediated disorders, and less frequently to overt malignancies.

Nephron-sparing surgery versus radical nephrectomy in the treatment of renal cell carcinoma up to 7 cm

Purpose

To compare the oncological outcome of nephron-sparing surgery versus radical nephrectomy in renal cell carcinoma up to 7 cm by retrospectively reviewing our surgical experience.

Materials and Methods

Data collected from 1290 consecutive patients, who underwent surgery for renal carcinoma, have been stored since 1983 into a dedicated database. The cases with unilateral carcinoma up to 7 cm, pT1a/pT1b/pT3a N0/Nx M0, followed up for a minimum of 12 months if disease-free were reviewed.

Results

732 patients were selected (mean follow-up: 72 months); 329 had a tumor less than 4 cm in diameter (182 cases of nephron-sparing surgery, 147 cases of nephrectomy), while for 403 of them the tumor was 4 cm or more (57 cases of nephron-sparing surgery, 346 cases of nephrectomy). The comparison between tumors less and equal to/more than 4 cm showed worse progression and disease-free survival rates for the latter, even though the type of surgery (nephron-sparing or radical) had no significant impact. Patients with extracapsular carcinoma >4 cm, treated with nephron-sparing surgery, had a particularly poor prognosis.

Conclusions

The conservative management can be cautiously suggested for renal cancers up to 7cm, since the prognosis worsens proportionally with the diameter increase, with no statistical difference for both nephron-sparing and radical surgery. Nephron-sparing surgery proved to be the suitable treatment modality also for pT3a tumors measuring <4 cm, whereas when the tumor size increases, an adequate intraoperative evaluation of peritumoral tissues is essential to rule out fat infiltration. These results comply with the few similar studies available in literature, and suggest the possibility of designing a prospective study aiming at comparing conservative and radical surgery in the management of renal carcinoma up to 7 cm.

Characterization and biological activity of the main flavonoids from Swiss Chard (Beta vulgaris subspecies cycla)

The molecular components of a phenolic fraction (P2), obtained from liquid chromatography of a Swiss Chard (Beta vulgaris subsp. cycla) extract, were identified using HPLC-ESI-MS/MS. The primary P2 components were: vitexin-2''O-rhamnoside, its demethylated form 2''-xylosylvitexin, isorhamnetin 3-gentiobioside, and rutin. P2 "in toto" and the single components were characterized for antioxidant capacity, antimitotic activity on MCF-7 human breast cancer cells and for toxicity to human lymphocytes and macrophages. P2 inhibited MCF-7 cell proliferation (IC(50) value = 9 microg/ml) without inducing apoptosis, showed no toxicity to human lymphocytes and slight toxicity to macrophages. Vitexin-2''O-rhamnoside strongly inhibited DNA synthesis in MCF-7 cells, whereas 2''-xylosylvitexin and isorhamnetin 3-gentiobioside were activators; combinations of activators and inhibitors maintained the over-all inhibitory effect.

[Cardiovascular remodelling in patients with sub-clinical hypothyroidism]

Sub-clinical hypothyroidism is defined by elevated serum thyroid-stimulating hormone level in the face of normal free thyroid hormone values. The role of sub-clinical hypothyroidism as independent risk factor for atherosclerosis has been suggested by clinical studies which demonstrated a higher prevalence of peripheral arterial disease, aortic atherosclerosis and coronary artery disease, in patients affected by this pathological condition. This association have been confirmed by the assessment of subclinical atherosclerosis by means of B-mode ultrasonography. Using this method an higher intima-media thickness (IMT) of carotid artery, a close marker of early atherosclerosis changes, have been found in patients with subclinical hypothyroidism compared to control euthyroid subjects. Levothyroxine replacement therapy of sub-clinical hypothyroidism was able to improve both the carotid IMT and atherogenic lipid profile, suggesting that lipid infiltration of the endothelium may represent a mechanism underlying the atherosclerotic process in patients with this pathological condition. Morphologic and functional changes of the myocardial tissue has been also demonstrated in patients with sub-clinical hypothyroidism, using ultrasonic backscatter video densitometry. All these data provide evidence of cardiovascular remodelling in patients with sub-clinical hypothyroidism. Vascular remodelling in sub-clinical hypothyroidism patients could be also studied by means of backscatter analysis of carotid artery, a method which allows the assessment of vascular sclerosis. Our preliminary results using this method suggested that not only atherosclerosis by also sclerosis characterises vascular remodelling in sub-clinical hypothyroidism patients.

Effect of L-thyroxine treatment on left ventricular function in subclinical hypothyroidism

Aim of this study was to investigate the effects of thyroxine treatment on myocardial regional left ventricular (LV) systolic and diastolic function in patients with subclinical hypothyroidism (SH) by tissue Doppler imaging (TDI). Forty-two patients (29 women and 13 men; mean age 52.2+/-15.1 years) with SH, as judged by elevated serum thyroid-stimulating hormone (TSH) levels (>3.6 mIU/l; range, 3.8-12.0) and free thyroid hormones (FT4 and FT3) within the normal range, and 30 euthyroid volunteers (21 women and nine men; mean age 50.4+/-17.1 years) underwent standard echocardiography and TDI-derived early (Em) and late (Am) diastolic velocities, systolic (Sm) velocity, and isovolumetric relaxation time (IVRTm). Patients were randomly assigned to receive or not L-thyroxine replacement therapy. All patients returned after 6 months to repeat thyroid function tests and the evaluation of all parameters. No significant differences were seen in the Sm peak between SH and control groups. Respect to controls, SH patients exhibited a lower Em, a higher Am, and, subsequently, a reduced Em/Am ratio of both lateral wall (LW) and interventricular septum (IVS) (P<0.001 for both). The IVRTm was distinctly longer in SH patients, as compared to controls (P<0.001). At 6 months, L-thyroxine-treated patients showed a significant increase of Em (P<0.01) and a subsequent increase of the Em/Am ratio (P<0.01), whereas IVRTm significantly reduced (P<0.05). No significant change in any of these parameters was observed in the untreated group. Our data suggest that SH is associated with a subtle, reversible impairment of myocardial function. TDI analysis detects and extends these functional defects by displaying alterations in regional myocardial function. L-T4 replacement therapy should be advised for these patients with the aim to correct preclinical cardiac dysfunction and prevent the development of clinically significant myocardial dysfunction.

Heart rate variability and QT dispersion in patients with subclinical hypothyroidism

The effect of subclinical hypothyroidism (SH) on cardiovascular autonomic function and ventricular repolarization has not been yet elucidated. The aim of the present study was to evaluate the dispersion of QT interval, i.e. an index of inhomogeneity of repolarization, and heart rate variability (HRV), i.e. a measure of cardiac autonomic modulation, in SH patients.

METHODS

The study included 42 patients (29 women and 13 men; mean age 53.2+/-14.2 years; body surface area 1.76+/-0.14 m2) with SH, as judged by elevated serum TSH levels (>3.6 mIU/l; range, 3.8-12.0) and normal free thyroid hormones (FT4 and FT3) and 30 euthyroid volunteer. Subjects with cardiac, metabolic, neurological disease or any other systemic disease that could affect autonomic activity were excluded from the study. Patients with SH and control subjects underwent a full history, physical examination, standard 12-lead ECG, and 24-h ambulatory ECG monitoring. To evaluate the effect of treatment with L-thyroxine on QT dispersion and HRV, 15 patients with SH were randomly assigned to receive therapy with L-thyroxine. All the subjects were evaluated at enrolment and after 6 months.

RESULTS

Patients with SH showed higher QT dispersion and lower HRV measures than healthy controls (P<0.01 for all). In SH patients, the standard deviation of N-Ns (SDNN) was negatively related to TSH (r=-0.42, P=0.006), while low frequency (LF)/high frequency (HF) ratio was positively related to TSH (r=0.42, P=0.006). Moreover, in SH patients both QT dispersion and QTc dispersion were positively related to TSH (r=0.64 and r=0.63, P<0.001 for both). After 6 months, the patients treated with L-tiroxine exhibited a reduction of QT dispersion and an increase of HRV parameters.

CONCLUSION

The results of the present study demonstrated that SH can alter autonomic modulation of heart rate and cause increased inhomogeneity of ventricular recovery times. Accordingly, early L-thyroxine treatment may be advised not only to prevent progression to overt hypothyroidism but also to improve abnormal cardiac autonomic function and ventricular repolarization inhomogeneity.

Serum levels of the interferon-γ-inducible α chemokine CXCL10 in patients with active Graves' disease, and modulation by methimazole therapy and thyroidectomy

Background

The interferon-γ-inducible chemokine CXCL10 is highly expressed in infiltrating inflammatory cells, and in thyrocytes in patients with Graves' disease. The aim of this study was to measure serum levels of CXCL10 in relation to thyroid function and treatment.

Methods

Serum levels of CXCL10 were measured in 22 patients with Graves' disease when hyperthyroid, when euthyroid under methimazole therapy, and 3 days after near-total thyroidectomy. They were compared with levels in three groups of age- and sex-matched controls: 44 subjects with no thyroid disorder, 44 patients with euthyroid autoimmune thyroiditis and 20 with toxic nodular goitre.

Results

Basal serum levels of CXCL10 in patients with Graves' disease were higher than levels in patients with toxic nodular goitre or no thyroid disorder, and similar to levels in patients with autoimmune thyroiditis (mean(s.d.) 167(121), 100(24), 78(46) and 142(107) pg/ml respectively; P &lt; 0·010). Among patients with Graves' disease, serum levels of CXCL10 were significantly higher in those aged over 50 years (P = 0·010), with a hypoechoic pattern at thyroid ultrasonography (P &lt; 0·001) or with hypervascularity (P = 0·001). CXCL10 levels in patients with Graves' disease decreased significantly when euthyroidism was achieved by methimazole therapy (P &lt; 0·010), and a further decrease was observed after thyroidectomy (P &lt; 0·010).

Conclusion

Serum levels of CXCL10 are higher in newly diagnosed hyperthyroid patients with Graves' disease than in those with toxic nodular goitre, and decrease when euthyroidism is achieved with antithyroid therapy. This high level may be related to the active inflammatory phase of Graves' disease. A further reduction of CXCL10 levels after thyroidectomy indicates that it is produced mainly in the thyroid in patients with autoimmune thyroid disease.

Spatial memory deficits in middle-aged mice correlate with lower exploratory activity and a subordinate status: role of hippocampal neurotrophins

The aim of the present work was to relate age-related individual differences in cognitive function with behavioural strategies employed in social and non-social challenges. To this purpose, the behaviour of adult (5-month-old) and middle-aged (13-month-old) CD-1 mice was scored in the social interaction, plus-maze, Morris water maze (MWM) and open-field tests. In addition, brain levels of nerve growth factor and brain-derived neurotrophic factor (BDNF) were analysed and correlated with the behaviours scored. Compared to adults, middle-aged mice showed greater anxiety in both non-social and social situations, spending less time in the open arms of the plus-maze and performing more freezing behaviour in response to aggression. Based upon their behaviour in the social interaction test, adult and middle-aged subjects were classified as dominant or subordinate and their behaviour in the open field, plus-maze and MWM tests subjected to factor analysis, taking into account age and social status. Results highlighted meaningful differences in exploratory strategies as a function of social status only in middle-aged subjects. In particular, middle-aged dominants were, overall, more explorative than same-aged subordinates, spending less time in peripheral areas and approaching more readily a novel object. Interestingly, in middle-aged mice, superior performance in the MWM task was associated with exploratory strategies exploited by dominants. At adulthood, BDNF hippocampal levels, but not specific behaviours, were positively correlated with the ability to learn a spatial task. Overall, data indicate that, in middle-aged subjects individual differences in exploratory strategies, rather than neurotrophin levels, are able to predict the degree of impairment in a spatial learning task.

Human lung fibroblast response to NGF, IL-1beta, and dexamethsone

It has been shown that lung mast cells, eosinophils, and fibroblasts are receptive to the action of nerve growth factor (NGF) and that NGF is released in to the bloodstream of subjects affected by allergic inflammatory response. The role of NGF in lung inflammatory disorders is unclear because there is evidence suggesting that NGF can be involved in both proinflammatory and anti-inflammatory responses. Lung fibroblasts play a marked role in inflammation. In this study we investigated the effect of NGF, interleukin 1beta (II-1beta), and dexamethasone (DEX) on human lung fibroblasts in vitro. We found that II-1beta, but not NGF, promotes fibroblasts' survival and that NGF stimulates trkA receptor expression, down regulates TFG-alpha, and has no effect on TNF-beta immunoreactivity. Moreover, DEX exerts different effects on NGF release by fibroblasts pre-exposed to II-1gamma. Our findings suggest that the NGF released by lung fibroblast during inflammation is not associated with the increase of proinflammatory factors such as TNF-alpha and II-1beta.

Anti-CD38 autoimmunity in children with newly diagnosed type 1 diabetes mellitus

AIMS

To test for anti-CD38 autoimmunity in children with newly-diagnosed type 1 diabetes mellitus (DM1).

METHODS

Serum anti-CD38 autoantibodies were detected by Western blot in 270 children (130 girls, 140 boys, mean age 8 +/- 4 years) with newly-diagnosed DM1 and 179 gender- and age-matched non-diabetic children. In 126 diabetic children, another blood sample was obtained 15 +/- 4 months after the diagnosis.

RESULTS

Anti-CD38 autoantibody titers at least 3 SD above the mean value for the control group were found in 4.4% of children with DM1 vs 0.6% of controls (chi2 = 5.8, p <0.016). No statistical differences were observed between anti-CD38 positive and negative patients in terms of phenotype. At follow-up, of six diabetic children who were positive for anti-CD38 antibodies, two were new cases. A positive correlation was found between the antibody titer of diabetic sera at diagnosis and follow up (r = 0.46, p <0.0001).

CONCLUSION

An autoimmune reaction against CD38, a protein expressed in human islets, is associated with newly-diagnosed DM1. In children with DM1, CD38 autoimmunity increases with time and persists.

The pro-fibrogenic effect of nerve growth factor on conjunctival fibroblasts is mediated by transforming growth factor-beta

BACKGROUND

Nerve growth factor (NGF) and nerve growth factor receptor (NGFR) expressions have been found to be increased in sub-conjunctival scarring.

OBJECTIVE

The aim of this study was to investigate the in vitro effects of NGF on some pro-fibrogenic properties of human conjunctival fibroblasts.

METHODS

Expression of NGF, trkA(NGFR) and p75NTR on human fibroblasts grown from conjunctival biopsies and incubated for 2 or 6 days with NGF were evaluated by immunofluorescence, RT-PCR, flow cytometry and ELISA. The fibrogenic effect of NGF on conjunctival fibroblasts was investigated by evaluating their migration (wound model), proliferation ([3H]-thymidine incorporation), collagen production (3H]-proline incorporation), expression of alpha-smooth muscle actin (alpha-SMA) (cell surface ELISA) and contraction of 3D collagen gels.

RESULTS

NGF induced the expression of p75NTR in the fibroblasts that constitutively expressed only trkA(NGF) and increased the migration of wounded fibroblasts, but not their proliferation and collagen production. NGF induced the conversion of fibroblasts into myofibroblasts expressing alpha-SMA, and enhanced their contraction of a collagen matrix. Interestingly, chronic NGF treatment induced transforming growth factor-beta1 (TGF-beta1) production by fibroblasts, and following specific TGF-beta neutralization, all the NGF-induced effects were completely abrogated.

CONCLUSION

Our findings indicate that NGF, via TGF-beta induction, is likely to be involved in the healing or fibrotic processes occurring in conjunctiva during some pathological conditions.

Expression of neurotrophic factors in cerebrospinal fluid and plasma of children with viral and bacterial meningoencephalitis

AIM

To evaluate the expression of neurotrophic factors (nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF)) and their association with the clinical-radiological characteristics and outcome of children with viral and bacterial meningoencephalitis (ME).

METHODS

Prospective observational clinical study performed on 13 children with ME and 12 controls with non-inflammatory obstructive hydrocephalus. Neurotrophic factor levels in the cerebro-spinal fluid (CSF) and plasma were measured using an immunoenzymatic assay.

RESULTS

High levels of NGF and BDNF were demonstrated in all patients, while GDNF levels did not undergo significant variations. NGF expression in the CSF was higher in viral ME than in bacterial ME and was correlated with CSF cellularity (particularly mononuclear cells). BDNF expression in the CSF was higher in bacterial ME than in viral ME and was correlated with CSF cellularity and blood platelet count. No relationships were noted between CSF protein or serum C-reactive protein levels and the expression of neurotrophic factors. Regarding clinical and radiological features, elevated NGF/BDNF levels in the CSF correlated with higher incidence of seizures and prolonged comatose state and with specific radiological lesions. No correlation was found between NGF/BDNF levels and final outcome.

CONCLUSIONS

The variations in neurotrophic factor levels may reflect an endogenous attempt at neuroprotection against biochemical and molecular changes during both viral and bacterial ME. The expression of these factors is likely to play a neuro-immunomodulatory or neurosurvival role in ME infections.

Relapsing Recto Vescical Fistula Treated According to the York Mason Technique

Recto-urinary fistulas are a rare event and their therapeutic management can be different. We present the case of a relapsing recto-vesical fistula, non-responsive to multiple therapeutic approaches, which was finally treated according to the York Mason technique to have immediate access to the fistula.

Stacking-fault based microscopic model for platelets in diamond

We propose a new model for {001} platelets in diamond based on the formation of a metastable stacking-fault. The core of the defect is a double layer of threefold coordinated sp2 carbon atoms embedded in the sp3 diamond matrix. The properties of the model were determined using ab initio calculations. All significant experimental signatures attributed to the platelets are fully accounted for. The model is also very appealing from the point of view of kinetics, since naturally occurring shearing processes will lead to the formation of the metastable fault.