Preliminary insights into RNA in CSF of pediatric SMA patients after 6 months of nusinersen

BACKGROUND

Spinal muscular atrophy (SMA) is a rare autosomal-recessive neurodegenerative disorder caused by mutations in survival motor neuron 1 (SMN1) gene, and consequent loss of function of SMN protein, which results in progressive loss of lower motor neurons, and muscular wasting. Antisense oligonucleotide (ASO) nusinersen (Spinraza®) modulates the pre-mRNA splicing of the SMN2 gene, allowing rebalance of biologically active SMN. It is administered intrathecally via lumbar puncture after removing an equal amount of cerebrospinal fluid (CSF). Its effect was proven beneficial and approved since 2017 for SMA treatment. Given the direct effect of nusinersen on RNA metabolism, the aim of this project was to evaluate cell-free RNA (cfRNA) in CSF of SMA patients under ASOs treatment for biomarker discovery.

METHODS

By RNA-sequencing approach, RNA obtained from CSF of pediatric SMA type 2 and 3 patients was processed after 6 months of nusinersen treatment, at fifth intrathecal injection (T6), and compared to baseline (T0).

RESULTS

We observed the deregulation of cfRNAs in patients at T6 and we were able to classify these RNAs into disease specific, treatment specific and treatment dependent. Moreover, we subdivided patients into "homogeneous" and "heterogeneous" according to their gene expression pattern. The "heterogeneous" group showed peculiar activation of genes coding for ribosomal components, meaning that in these patients a different molecular effect of nusinersen is observable, even if this specific molecular response was not referable to a clinical pattern.

CONCLUSIONS

This study provides preliminary insights into modulation of gene expression dependent on nusinersen treatment and lays the foundation for biomarkers discovery.

New CACNA1A deletions are associated to migraine phenotypes

Background

Familial hemiplegic migraine type 1 (FHM1) is a form of migraine with aura caused by heterozygous mutations in 4 genes: CACNA1A, ATP1A2, SNC1A and PRRT2, but further heterogeneity is expected. Here have been described clinical and molecular features in patients suffering from migraine with Aura (MA), without (MO) and hemiplegic migraine attacks.

Next Generation Sequencing by TruSeq Custom Amplicon for CACNA1A and ATP1A2 gene has been performed. All genetic variants have been confirmed by Sanger sequencing and all samples were also analyzed with MLPA assay for ATP1A2-CACNA1A genes to detect duplication or deletion. All MLPA data were verified by Real Time PCR.

Results

Sequencing analysis showed 3 point mutations, two novel variants and one already described in literature. Moreover, MLPA analysis showed 3 deletions in 9 sporadic hemiplegic migraine (18%), in 3 patients with non-hemiplegic migraine (4.1%) and in 3 patients affected by episodic ataxia (20%). Two sporadic patients showed a deletion in exons 41–43, while the rest of HM patients (5) showed a deletion in the terminal part of the CACNA1A gene.

About episodic ataxia, we have identified deletions in exon 12–15 and in exon 47. Finally, in migraine patients, we have found different subjects affected by different phenotypes deleted in exon 47.

Conclusion

This work highlights the importance to complement analysis as direct sequencing with quantitative analysis (MLPA). In fact, intragenic CACNA1A rearrangements have been detected. Our work demonstrated that deletions in CACNA1A gene may be associated also to different migraine phenotypes.

Chronic inflammatory demyelinating polyneuropathy: evaluation of the vestibular system with cervical and ocular vestibular evoked myogenic potentials

PURPOSE

To investigate the possibility of vestibular damage in a group of patients suffering from chronic inflammatory demyelinating polyneuropathy (CIDP) using a diagnostic protocol including the caloric test, C-VEMPs and O-VEMPs.

METHODS

Twenty patients suffering from CIDP (mean age 58.5 years, range 33-80 years; 4 women and 16 men) were investigated. To assess any eventual audio-vestibular involvement, all patients of the study underwent pure tone audiometry, Fitzgerald-Hallpike caloric vestibular test, C-VEMPs and O-VEMPs.

RESULTS

In 11 patients with CIDP values of both O-VEMPs and C-VEMPs were either absent or abnormal. An absent trace at O-VEMPs testing occurred in 36% of these pathological patients, whereas an increase of n10 latency and amplitude was present in the other 64% .

CONCLUSIONS

A specific diagnostic protocol including the caloric test, C-VEMPS, O-VEMPS, could be useful when employed for identifying vestibular damage in CIDP patients.

Usher's Syndrome Type II: A Comparative Study of Genetic Mutations and Vestibular System Evaluation

Objective Usher's syndrome type II (USH2) is characterized by moderate to profound congenital hearing loss, later onset of retinitis pigmentosa, and normal vestibular function. Recently, a study investigating the vestibular function of USH2 patients demonstrated a pathologic response to vestibular tests. In this cross-sectional study we performed vestibular tests of a group patients with genetic diagnosis of USH2 syndrome to demonstrate if vestibular damage is present in USH2 patients. Study Design Cross-sectional study. Setting Tertiary referral center. Subjects and Methods Mutated genes of 7 patients with a clinical diagnosis of USH2 were evaluated. Vestibular function was investigated by audiometry, Fitzgerald-Hallpike caloric vestibular testing, cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and video head impulse test (v-HIT). Results Genetic tests confirmed the USH2 diagnosis in 5 of 7 patients examined, with 1 patient reporting a unique mutation on genetic tests. Four (80%) of the 5 patients with a genetic diagnosis of USH2 showed pathological O-VEMPs. Two patients (40%) reported bilateral absent or abnormal values of C-VEMPs. The superior semicircular canal presented a significant deficit in 2 (40%) patients. The same 2 cases showed a pathologic response of the v-HIT of the horizontal semicircular canal. Finally, the posterior semicircular canal presented a significant deficit in 4 (40.0%) patients. Conclusion A vestibular evaluation with vestibular evoked myogenic potentials and v-HIT seems to identify latent damage to the vestibular receptors of USH2 patients.

Vestibular neurolabyrinthitis: a follow-up study with cervical and ocular vestibular evoked myogenic potentials and the video head impulse test

OBJECTIVES

The aim of this study was to evaluate prospectively, in a group of patients affected by vestibular neurolabyrinthitis (VN), a diagnostic protocol including cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and the video head impulse test (vHIT).

METHODS

The diagnosis of VN was based on the patient's clinical history, an absence of associated auditory or neurologic symptoms, and a neuro-otological examination with an evaluation of lateral semicircular canal function by use of the Fitzgerald-Hallpike caloric vestibular test and the ice test.

RESULTS

In our series, 55% of the cases were superior and inferior VN, 40% were superior VN, and 5% were inferior VN. These cases, however, comprised different degrees of vestibular involvement, as the individual vestibular end organs have different prognoses. Four patients had only deficits of the horizontal and superior semicircular canals or their ampullary nerves.

CONCLUSIONS

The implementation of C-VEMPs, O-VEMPs, and the vHIT in a vestibular diagnostic protocol has made it possible to observe patients with ampullary VN in a way that has not been feasible with other types of vestibular examinations. The age of the patient seems to have some impact on recovery from VN. When recovery occurs in the utricular and saccular nerves first and in the ampullary nerves subsequently, it may be reasonable to expect a more favorable outcome.

Selective Vestibular Neurolabyrinthitis of the Lateral and Superior Semicircular Canal Ampulla and Ampullary Nerves

Objectives:

The diagnosis of vestibular neurolabyrinthitis is based on the sudden appearance of vertigo that lasts for hours or days without associated cochlear or central nervous system signs or symptoms. The advent of the video head impulse test, cervical vestibular evoked myogenic potential testing, and ocular vestibular evoked myogenic potential testing has provided interesting clinical evidence for evaluating and monitoring the damage to specific compartments of the vestibular apparatus. These various methods of testing individual end-organ functions may have a clinical impact on the vestibular workup of neurolabyrinthitis.

Methods:

This report describes 3 patients with acute vestibular neurolabyrinthitis in whom caloric tests, cervical vestibular evoked myogenic potentials, ocular vestibular evoked myogenic potentials, and the video head impulse test led to a suspicion of peripheral vestibular deficits of the lateral or superior semicircular canal ampulla or ampullary nerves.

Results:

In our patients, the examination results (normal hearing, absence of responses on caloric testing, and bilateral preservation of cervical and ocular vestibular evoked myogenic potentials) disclosed an acute partial superior vestibular neurolabyrinthitis.

Conclusions:

To our knowledge, these are the first reported cases in which selective damage to the lateral and superior semicircular canals and their nerves caused by neurolabyrinthitis was demonstrated clinically. Our clinical results indicate that the damage can be selective for specific vestibular end organs.

Rosiglitazone reverses increased duodenal inhibitory response in spontaneously hypertensive rats

BACKGROUND

Thiazolidinediones (TZDs) including rosiglitazone (ROSI) are insulin sensitizing agents with beneficial gastrointestinal effects. However, no studies are available on TZDs effect in gastrointestinal motility. We evaluated the effects of ROSI on gastrointestinal inhibitory neurotransmission focusing on the modulatory roles of nitric oxide synthase/nitric oxide (NOS/NO) and heme oxygenase/carbon monoxide (HO/CO) pathways.

METHODS

Spontaneously hypertensive rats (SHR) were used as model of insulin resistance. Duodenal strips were obtained from vehicle-treated SHR, ROSI-treated SHR (5 mg kg(-1) by gavage daily per 6 weeks), and Wistar Kyoto (WKY). Inhibitory responses to electrical field stimulation (EFS) were evaluated in the presence of HO inhibitor zinc protoporphyrin IX (ZnPPIX, 10 μmol L(-1)) or NOS inhibitor N(G)-nitro-L-arginine (L-NNA, 100 μmol L(-1)), alone and in combination. Protein levels of HO and NOS isoforms were evaluated by immunohistochemistry and western blot analysis.

KEY RESULTS

Basal responses to EFS were significantly increased in duodenum strips from vehicle-treated SHR vs WKY. This effect was reversed in ROSI-treated SHR. The EFS-mediated relaxation was comparably reduced by ZnPPIX in WKY and SHR, but not in ROSI-treated SHR animals. The L-NNA reduced EFS response to a similar extent in WKY and ROSI -treated SHR, but its effect was significantly higher in vehicle-treated SHR. Expression of HO-1 protein was significantly lower, whereas HO-2 protein levels were unchanged in ROSI-treated SHR with respect to vehicle-treated SHR. Finally, increased levels of nNOS in vehicle-treated SHR were reduced in ROSI-treated SHR.

CONCLUSIONS & INFERENCES

Chronic ROSI treatment reverses increased SHR duodenal inhibitory response acting on CO and NO components.

Curcumins promote monocytic gene expression related to β-amyloid and superoxide dismutase clearance

Neurodegenerative diseases are associated with accumulation of modified proteins or peptides including amyloid-β (Aβ) in Alzheimer's disease (AD), and misfolded superoxide dismutase-1 (SOD-1) in amyotrophic lateral sclerosis (ALS). Clearance of Aβ or SOD-1 by the innate immune system may be important for controlling or preventing disease onset. Curcumins restore Aβ phagocytosis by peripheral blood mononuclear cells (PBMCs) from AD patients and Aβ clearance with upregulation of key genes including MGAT3, vitamin D receptor (VDR) and Toll-like receptors (TLRs). Certain curcumins inhibit inflammatory processes of PBMCs from ALS patients. We developed an in vitro system using human monocytes from patients and monocytic cell lines (i.e. U-937, THP-1) for evaluating curcuminoid potency of innate immune cell stimulation. Bisdemethoxycurcumin and certain analogs potentiated MGAT3,VDR and TLR gene expression 3- to 300-fold in U-937 cells. The effect of curcumins on inflammation in monocytes from patients with ALS was examined. Recursive medicinal chemistry was applied to identify compounds that stimulate the innate immune system for use in the clearance of Aβ in AD and the reversal of neuroinflammation and defective SOD-1 accumulation in ALS.

Evaluation in vitro of synthetic curcumins as agents promoting monocytic gene expression related to β-amyloid clearance

Accumulation of amyloid-beta (Aβ) is one of the hallmarks of Alzheimer's disease (AD), and efficient clearance of Aβ by cells of the innate immune system may be an important mechanism for controlling or preventing disease onset. It was reported that peripheral blood mononuclear cells (PBMCs) of most AD patients are defective in the phagocytosis of soluble Aβ. Natural curcumins were shown to restore Aβ phagocytosis by AD PBMCs and to up-regulate the expression of key genes including MGAT3 and those encoding Toll-like receptors (TLRs). Bisdemethoxycurcumin (BDC), a minor component of natural curcumin, was shown to have the greatest potency for stimulating AD PBMCs. Because natural curcumins have inherent limitations with regard to physicochemical properties, synthetic curcumin analogues were developed that showed improved solubility, stability, and bioavailability. An in vitro system using human monocytic cell lines (U-937, THP-1) was used to evaluate analogues for the potency of innate immune cell stimulation. These cell lines showed responses to curcuminoids and to 1α,25-dihydroxyvitamin D3 (VD3) resembling those seen in human PBMCs. From more than 45 curcuminoids analyzed, the most potent compounds possessing enhanced pharmaceutical properties were identified. The most promising candidates included prodrug versions containing water solubility-enhancing amino acids and stability-increasing modifications near the central diketone. In vivo studies showed compound (5) substantially increased bioavailability by combining several promising structural modifications. Studies examining ex vivo phagocytosis of Aβ and bead particles in mouse microglia showed that BDC and several water-soluble analogues were quite effective compared to curcumin or an unnatural analogue. In vitro studies using monocytic cell lines reported herein complement those using human PBMCs and represent a routinely accessible and uniform cellular resource allowing direct comparisons between compounds.

Electrocatalysts for methanol oxidation based on platinum/carbon nanofibers nanocomposite

New carbon nanomaterials, i.e., carbon nanotubes and nanofibers, with special physico-chemical properties, are recently studied as support for methanol oxidation reaction electrocatalysts replacing the most widely used carbon black. Particularly, carbon fibrous structures with high surface area and available open edges are thought to be promising. Platelet type carbon nanofibers, which have the graphene layers oriented perpendicularly to the fiber axis, exhibit a high ratio of edge to basal atoms. Different types of carbon nanofibers (tubular and platelet) were grown by plasma enhanced chemical vapour deposition on carbon paper substrates. The process was controlled and optimised in term of growth pressure and temperature. Carbon nanofibers were characterised by high resolution scanning electron microscopy and X-ray photoelectron spectroscopy to assess the morphological properties. Then carbon nanofibers of both morphologies were used as substrates for Pt electrodeposition. High resolution scanning electron microscopy images showed that the Pt nanoparticles distribution was well controlled and the particles size went down to few nanometers. Pt/carbon nanofibers nanocomposites were tested as electrocatalysts for methanol oxidation reaction. Cyclic voltammetry in H2SO4 revealed a catalyst with a high surface area. Cyclic voltammetry in presence of methanol indicated a high electrochemical activity for methanol oxidation reaction and a good long time stability compared to a carbon black supported Pt catalyst.

Platinum-gold nanoclusters as catalyst for direct methanol fuel cells

Nanosized platinum-gold alloys clusters have been deposited on gas diffusion electrode by sputter deposition. The deposits were characterized by FE-SEM, TEM and XPS in order to verify the formation of alloy nanoparticles and to study the influence of deposition technique on the nanomorphology. The deposition by sputtering process allowed a uniform distribution of metal particles on porous surface of carbon supports. Typical island growth mode was observed with the formation of a dispersed metal nanoclusters (mean size about 5 nm). Cyclic voltammetry was used to determine the electrochemical active surface and the electrocatalytic performance of the PtAu electrocatalysts for methanol oxidation reaction. The data were re-calculated in the form of mass specific activity (MSA). The sputter-catalyzed electrodes showed higher performance and stability compared to commercial catalysts.

Cardiovascular complications in diabetes: lessons from animal models

Micro- and macro-vascular complications are the leading causes of morbidity and mortality in type 1 and type 2 diabetic patients. Despite the vast clinical experience linking diabetic metabolic abnormalities to cardiovascular lesions, the molecular basis of individual susceptibility to diabetic cardiovascular injury is still largely unknown. Significant advances in this area may come from studies on suitable animal models. Although no animal model can accurately reproduce the human disease, experimental studies in animals have the great advantage to eliminate factors such as ethnicity, economic and geographic variables, drug interactions, diet, gender and age differences that importantly limit clinical studies. Indeed, appropriate animal models have provided important information on genetic and environmental risks of diabetes, and helped to dissect molecular mechanisms underlying the development, progression and therapeutic control of this disease. Unfortunately, none of the diabetic models presently available fully mimics the human syndrome. Therefore, the current knowledge on the pathogenesis of cardiovascular complications relies on the evaluation of distinct phenotypes from various diabetic models. In addition to strains prone to diabetes, this disease can be induced by surgical, pharmacological or genetic manipulation in several animal species. Rodents are the most used, although some studies are still performed in larger animals as rabbits, cats, pigs or monkeys. Far from being exhaustive, this work should serve as a general overview of the most relevant clues provided by major species and models for the overall comprehension of cardiovascular complications in type 1 and type 2 diabetes.

Vestibular evoked periocular potentials in Meniere's disease after glycerol testing

OBJECTIVES

The present investigation was specifically designed to evaluate the clinical application of vestibular evoked periocular potentials (VEPPs) in the diagnosis of endolymphatic hydrops.

METHODS

We compared the results of the traditional pure tone audiometry glycerol test with those of the vestibular evoked myogenic potential (VEMP) glycerol test and the VEPP glycerol test in 22 patients affected by unilateral endolymphatic hydrops.

RESULTS

Some patients had positive depletive tests with both VEMPs and VEPPs, and other patients had positive tests with either VEMPs or VEPPs.

CONCLUSIONS

Our outcomes confirmed that vestibular evoked potentials represent a useful additional diagnostic tool in the diagnosis of endolymphatic hydrops. The role of VEPPs in this particular issue was not inferior to that of VEMPs. The outcomes also suggested that not only the saccule, but also the utriculus, may be involved in the genesis of VEPPs.

Hernia repair with porcine small-intestinal submucosa

PURPOSE

Although at present nonabsorbable meshes are the preferred material for tension-free hernioplasty, some problems with their use have yet to be addressed (i.e., chronic pain and infections). In order to address these disadvantages, a collagen-based material, the porcine small-intestinal submucosa mesh (Surgisis Inguinal Hernia Matrix, Cook Surgical, Bloomington, IN, USA), has recently been developed for hernia repair.

METHODS

With the aim of investigating the clinical safety and effectiveness of Surgisis IHM inguinal hernia repair, we report our experience of 45 consecutive hernioplasties with a medium-term follow-up. The surgical technique for the use of this material in hernioplasty is described in detail.

RESULTS

Although some local (i.e., seromas) and general (i.e., hyperpyrexia), complications appeared in the immediate postoperative period (all of them disappeared spontaneously), no rejection or infection was observed after operations. At the 2-year follow-up, a low degree of pain and discomfort and no recurrences were observed.

CONCLUSIONS

We conclude that the Surgisis IHM hernioplasty is feasible with promising results and, from a clinical perspective, seems safe and effective.

Use of porcine dermal collagen graft (Permacol) for hernia repair in contaminated fields

BACKGROUND

Complicated hernias often involve contaminating surgical procedures in which the use of polypropylene meshes can be hazardous. Prostheses made of porcine dermal collagen (PDC) have recently been proposed as a means to offset the disadvantages of polypropylene meshes and have since been used in humans for hernia repairs. The aim of our study was to evaluate the safety and efficacy of incisional hernia repair using PDC as a mesh in complicated cases involving contamination.

METHODS

A prospective study of hernia repair of complicated incisional hernias with contamination using PDC grafts was carried out at the Department of General, Emergency and Transplant Surgery of St Orsola-Malpighi University Hospital.

RESULTS

From January 2004 up to the writing of this article, seven patients were treated for complicated incisional hernias with a PDC prosthesis. In six out of seven patients a bowel resection was carried out. There were not surgical complications. Morbidity was 14.2%. No recurrences and wound infections were observed.

CONCLUSIONS

Incisional hernioplasty using PDC grafts is a potentially safe and efficient approach in complicated cases with contamination.

Experimental evaluation of Surgisis as scaffold for neointestine regeneration in a rat model

The aim of the study was to evaluate the use of Surgisis (Cook Biotech Inc.), a porcine derived extracellular matrix already used in tissue engineering, as a scaffold for neointestinal regeneration in a rat model. A 3-cm length of tubular Surgisis graft was interposed with bilateral anastomoses in the middle of an isolated ileal loop of Sprague Dawley rats with an ileostomy. The grafts were harvested and analyzed using histology and immunohistochemistry at 24 weeks after operation. Macroscopic examination revealed neither stenosis nor adhesions in the area surrounding the neointestine. The regenerated small bowel showed a mean shrinkage of 30.7% (range 20%-40%). Histologic and immunohistochemical evaluation showed a well-developed three layers of mucosa and smooth muscle and serosa in the regenerated bowel wall that were similar to those of the normal bowel with evident neovascularization. Also, the regeneration of smooth muscle fibers and innervation were evident. The preliminary results of this study showed that Surgisis allowed rapid regeneration of mucosa and smooth muscle and therefore may be a promising material for the creation of a neointestine.

On the difference in scattering behavior of cyclic and linear polymers in bulk

It has been suggested that, due to topological constraints, rings in the melt may assume a more compact shape than Gaussian chains. In this paper, we exploit the availability of narrow fractions of perdeuterated linear and cyclic polydimethylsiloxane (PDMS) and, through the analysis of the small angle neutron scattering (SANS) profiles, demonstrate the difference in scattering properties of linear and cyclic PDMS molecules. As expected for Gaussian chains, for the H/D linear PDMS samples, log-log plots of the scattered intensity versus scattering vector Q display a Q((-2)) dependence. However, for H/D cyclic blends, the scaling exponent is higher than 2, as predicted by computer simulations reported in the literature. We show that cyclic molecules in bulk display the characteristic maximum in plots of scattered intensity versus Q((-2)) that is expected on the basis of Monte Carlo calculations and from the Casassa equation [E. F. Casassa, J. Polym. Sci. A 3, 605 (1965)]. It is also shown that, for rings, the Debye equation [P. Debye, J. Appl. Phys. 15, 338 (1944)] is no longer appropriate to describe the SANS profiles of H/D cyclic blends, at least up to M(w) approximately 10 000. For these samples, the Casassa form factor gives a better representation of the SANS data and we show that this function which was developed for monodisperse cyclics is still adequate to describe our slightly polydisperse samples. Deviations from all above observations are noted for M(w)>11 000 and are attributed to partial contamination of cyclic samples with linear chains. The failure of both the Debye and the Casassa form factors could be due to contamination of the cyclic fractions by linear polymers or to a real conformational change.

Lichtenstein repair of inguinal hernia with Surgisis inguinal hernia matrix soft-tissue graft in immunodepressed patients

While polypropylene mesh remains the preferred prosthesis material for hernioplasties, there are some problems with infections, intestinal obstruction and fistulization, and migration particularly in immunodepressed patients. A new degradable and reabsorbable material, the porcine small intestinal submucosa (Surgisis) has been developed for hernia repairs in humans. This prospective study evaluated the safety and efficacy of Lichtenstein hernioplasty using the Surgisis inguinal hernia matrix soft-tissue graft as a mesh in ten immunodepressed subjects. Six subjects were HIV-positive in the immunodepressive phase, and the other four had undergone transplantation (three kidney, one liver). There were no intraoperative or postoperative complications, recurrences, or wound infections. Thus Lichtenstein's hernioplasty using the Surgisis inguinal hernia matrix soft-tissue graft in immunodepressed patients promises safety and efficacy.

Selective inhibition of osteoclast vacuolar H(+)-ATPase

The proton pump expressed on the plasma membrane of bone resorbing osteoclasts, and which mediates the acidification of the extracellular environment in resorption lacuna, belongs to the family of vacuolar H(+)-ATPases, which are enzymes ubiquitously distributed among all cells and are evolutionary conserved. These pumps have two functional domains: a peripherally associated cytoplasmatic section, and a proton channel composed of several subunits one of which, the 116 kDa subunit, is expressed exclusively in osteoclasts and confers unique functional and pharmacological properties to the osteoclast V-ATPase. It was demonstrated that inhibition of this pump can abolish bone resorption; therefore, osteoclast-selective inhibitors could provide novel and useful agents for the treatment of osteoporosis. This paper reviews the medicinal chemistry approaches that have allowed to obtain such new agents, most of which have been designed starting from the natural macrolide antibiotic bafilomycin A(1), a potent and selective inhibitor of all V-ATPases. Identification of SAR and of minimal structural requirements for bafilomycin activity have allowed to obtain (2Z,4E)-5-(5,6-dichloroindolyl)-2-methoxy-N-(1,2,2,6,6-pentamethylpiperidin-4-yl)-2,4-pentadienamide (SB-242784) which inhibits the osteoclastic proton pump and bone resorption in vitro. Although it inhibits the activity of non-osteoclastic proton pumps as well, it appears to have reasonable selectivity and its administration for 6 months prevented the loss of femoral and vertebral BMD in ovariectomized rats, without any significant renal effects in control and acid-loaded animals. Other independent approaches that did not start from bafilomycin have led to the discovery of a different class of V-ATPase inhibitors, among which 4-(2,6-dichlorobenzoyl)amino-2-trifluoromethyl(benzoimidazol-1-yl)acetyl morpholine (FR177995) was the most effective in preventing bone resorption in an ovariectomized rat model of osteoporosis. These compounds are of great pharmaceutical and medical interest because they allow to target a specific function of the osteoclast; however, only clinical trials might demonstrate whether they have significant advantages over other inhibitors of bone resorption for the treatment of osteoporosis.

[Expression of epithelial oncoproteins in large intestine neoplasms]

The high incidence of the colorectal cancer in the industrialized countries has drawn the interest of the scientific community to detect and investigate its morphologic precursors. Growth factors and oncoproteins could be useful to investigate the morphologic and biologic evolution of precancerous lesions of the large bowel. Therefore the Authors report the results obtained from 30 selected patients with hyperplastic and adenomatous polyps, and different histotypes of colorectal cancer, investigated using the EGF-r and p62 protein expression. The results show the potential usefulness of such markers to evaluate the biology of intestinal tumors.

Use of prosthetic mesh in complicated incisional hernias

BACKGROUND

Incisional hernia (IH) repair with conventional techniques is associated with high recurrence rate. Surgical repair using prosthetic biomaterials is becoming increasingly popular. On the basis of the good results an increasing number of surgeons have begun to use this technique. However prosthesis use in contaminated fields is still debated. In complicated IH contaminating surgical procedure are often performed and the use of meshes can be hazardous. The aim of this study was to report our experience about the treatment of complicated IH with prosthetic materials in an emergency surgery setting.

METHODS

From November 1995 to November 2001 55 patients were submitted to emergency surgical treatment for complicated IH. Eleven patients were treated using a prosthetic device. Patients mean age was 71.3 (range 38-91). About 70% of patients had concomitant major cardiac or pulmonary diseases.

RESULTS

Thirty-two IH were strangulated, 23 were incarcerated. In all patients a viscerolysis was carried out. In 6 patients a small bowel resection was done and in 4 subjects a large bowel resection was performed. Eight patients were submitted to omental resection. There were not differences in morbidity and mortality between the studied group. Recurrence rate was significantly lower in prosthetic treated group.

CONCLUSIONS

We concluded that prosthetic repair of complicated IH is feasible in selected cases allowing abdominal wall anatomy re-establishment.

Stepwise Modulation of Neurokinin-3 and Neurokinin-2 Receptor Affinity and Selectivity in Quinoline Tachykinin Receptor Antagonists

A stepwise chemical modification from human neurokinin-3 receptor (hNK-3R)-selective antagonists to potent and combined hNK-3R and hNK-2R antagonists using the same 2-phenylquinoline template is described. Docking studies with 3-D models of the hNK-3 and hNK-2 receptors were used to drive the chemical design and speed up the identification of potent and combined antagonsits at both receptors. (S)-(+)-N-(1-Cyclohexylethyl)-3-[(4-morpholin-4-yl)piperidin-1-yl]methyl-2-phenylquinoline-4-carboxamide (compound 25, SB-400238: hNK-3R binding affinity, K(i) = 0.8 nM; hNK-2R binding affinity, K(i) = 0.8 nM) emerged as the best example in this approach. Further studies led to the identification of (S)-(+)-N-(1,2,2-trimethylpropyl)-3-[(4-piperidin-1-yl)piperidin-1-yl]methyl-2-phenylquinoline-4-carboxamide (compound 28, SB-414240: hNK-3R binding affinity, K(i) = 193 nM; hNK-2R binding affinity, K(i) = 1.0 nM) as the first hNK-2R-selective antagonist belonging to the 2-phenylquinoline chemical class. Since some members of this chemical series showed a significant binding affinity for the human mu-opioid receptor (hMOR), docking studies were also conducted on a 3-D model of the hMOR, resulting in the identification of a viable chemical strategy to avoid any significant micro-opioid component. Compounds 25 and 28 are therefore suitable pharmacological tools in the tachykinin area to elucidate further the pathophysiological role of NK-3 and NK-2 receptors and the therapeutic potential of selective NK-2 (28) or combined NK-3 and NK-2 (25) receptor antagonists.

Discovery of a novel antitumor benzolactone enamide class that selectively inhibits mammalian vacuolar-type (H+)-atpases

A series of naturally occurring compounds reported recently by multiple laboratories defines a new small-molecule class sharing a unique benzolactone enamide core structure and diverse biological actions, including inhibition of growth of tumor cells and oncogene-transformed cell lines. Here we show that representative members of this class, including salicylihalamide A, lobatamides A-F, and oximidines I and II inhibit mammalian vacuolar-type (H+)-ATPases (V-ATPases) with unprecedented selectivity. Data derived from the NCI 60-cell antitumor screen critically predicted the V-ATPase molecular target, while specific biochemical assays provided confirmation and further illumination. The compounds potently blocked representative V-ATPases from human kidney, liver, and osteoclastic giant-cell tumor of bone but were essentially inactive against V-ATPases of Neurospora crassa and Saccharomyces cerevisiae and other membrane ATPases. Essential regulation of pH in cytoplasmic, intraorganellar, and local extracellular spaces is provided by V-ATPases, which are ubiquitously distributed among eukaryotic cells and tissues. The most potent and selective V-ATPase inhibitors heretofore known were the bafilomycins and concanamycins, which do not discriminate between mammalian and nonmammalian V-ATPases. Numerous physiological processes are mediated by V-ATPases, and aberrant V-ATPase functions are implicated in many different human diseases. Previous efforts to develop therapeutic pharmacological modulators of V-ATPases have been frustrated by a lack of synthetically tractable and biologically selective leads. Therefore, availability of the unique benzolactone enamide inhibitor class may enable further elucidation of functional and architectural features of mammalian versus nonmammalian V-ATPase isoforms and provide new opportunities for targeting V-ATPase-mediated processes implicated in diverse pathophysiological phenomena, including cancer.

[Argyrophilic nucleolar organizer regions (AgNORs) as malignancy biomarkers in colorectal neoplasms]

The high incidence of intestinal cancer has aroused strong interest in researching and trying to discover its morphologic precursors. In this contest the study of nucleolar organizing regions could be interesting as prognostic factor for bowel neoplasm and useful for differential diagnosis of intestinal diseases. The Authors report on the results of their study performed on 30 selected samples from 6 different bowel lesions.

Novel bone antiresorptive agents that selectively inhibit the osteoclast V-H+-ATPase

The vacuolar proton pump (V-ATPase) located on the plasma membrane of the osteoclast is a potential molecular target for the discovery of novel bone antiresorptive agents useful for the treatment of osteoporosis. In order to design novel compounds able to selectively inhibit the osteoclast V-ATPase we firstly identified the minimal structural requirements of bafilomycin A1, a macrolide antibiotic which potently inhibits all V-ATPases. This information allowed the design of 2-(indole)pentadienamide derivatives whose optimization led to a novel class of potent inhibitors that demonstrated a high degree of selectivity for the osteoclast V-ATPase. The most interesting derivative, SB-242784, was able to inhibit bone resorption by human osteoclasts in vitro and to completely prevent ovariectomy-induced bone loss in rats when administered orally at 10 mg kg(-1) day(-1). Structure activity relationships of this class of compounds were investigated further by replacing the 2,4-pentadienoyl chain with suitable spacers able to maintain the correct orientation and distance between the indole ring and the amide moiety.

A sensitive method to assay the xanthine oxidase activity in primary cultures of cerebellar granule cells

Since xanthine oxidase (XO, Xanthine:oxidoreductase, E.C.1.2.3.22) is a key enzyme in reactive oxygen specie formation which plays a major role in cell oxidative stress, the availability of a sensitive and simple assay useful to detect its activity in monolayer cell cultures is worthwhile. In order to achieve this, we developed a method in which the conversion of pterine into isoxanthopterin is monitored fluorimetrically. Temperature assay was 50 degrees C. The activity of XO was detected in cerebellar granule cells exposed to glutamate. Since XO is formed from protease-dependent xanthine dehydrogenase processing, its activity appearance was found to be prevented by the protease inhibitor, leupeptin, as well as the glutamate NMDA-receptor inhibitor, MK-801, and the Ca(++) complexing agent, EGTA. The reported novel protocol, at variance with a conventional method, is shown to be a simple, fast, sensitive and relatively cheap method to assay XO activity. In addition, the reported assay can be applied to any cell type in culture.

Chemistry and structure activity relationships of bafilomycin A1, a potent and selective inhibitor of the vacuolar H+-ATPase

Bafilomycin A1, a macrolide antibiotic isolated from the fermentation of Streptomyces spp., is a potent and selective inhibitor of vacuolar-type proton translocating ATP-ases (V-ATPases) and was used to study the physiological role of this class of enzymes. An extensive chemical effort on the unusual structure of this macrolide led to the synthesis of significantly different bafilomycin derivatives. None of the new analogues was more potent than the parent compound but provided a significant amount of information about the structural requirements for the inhibitory activity of bafilomycin A1 in particular on chicken osteoclast (cOc) ATPase. The vinylic methoxy group adjacent to a carbonyl function, the dienic system and the hydroxy group at position 7 were recognized to be essential features for bafilomycin V-ATPase-inhibitory activity. This information was utilized to design simplified novel derivatives as inhibitors of bone resorption.

Glutamate neurotoxicity in rat cerebellar granule cells involves cytochrome c release from mitochondria and mitochondrial shuttle impairment

To gain some insight into the mechanism by which glutamate neurotoxicity takes place in cerebellar granule cells, two steps of glucose oxidation were investigated: the electron flow via respiratory chain from certain substrates to oxygen and the transfer of extramitochondrial reducing equivalents via the mitochondrial shuttles. However, cytochrome c release from intact mitochondria was found to occur in glutamate-treated cells as detected photometrically in the supernatant of the cell homogenate suspension. As a result of cytochrome c release, an increase of the oxidation of externally added NADH was found, probably occurring via the NADH-b5 oxidoreductase of the outer mitochondrial membrane. When the two mitochondrial shuttles glycerol 3-phosphate/dihydroxyacetone phosphate and malate/oxaloacetate, devoted to oxidizing externally added NADH, were reconstructed, both were found to be impaired under glutamate neurotoxicity. Consistent early activation in two NADH oxidizing mechanisms, i.e., lactate production and plasma membrane NADH oxidoreductase activity, was found in glutamate-treated cells. In spite of this, the increase in the cell NADH fluorescence was found to be time-dependent, an index of the progressive damage of the cell.

Replacement of the quinoline system in 2-phenyl-4-quinolinecarboxamide NK-3 receptor antagonists

Results from a medicinal chemistry approach aimed at replacing the quinoline ring system in the potent and selective human neurokinin-3 (hNK-3) receptor antagonists 1-4 of general formula I are discussed. The data give further insight upon the potential NK-3 pharmacophore. In particular, it is highlighted that both the benzene-condensed ring and the quinoline nitrogen are crucial determinants for optimal binding affinity to the hNK-3 receptor. Some novel compounds maintained part of the binding affinity to the receptor (5, 6, 10 and 13) and compound 5, featuring the naphthalene ring system, appears to be suitable for further modifications; it offers the option to introduce electron-withdrawing groups at position 2 and 4, conferring on the ring an overall electron-deficiency similar to that of the quinoline.

[Virtual reality: a simple joke or therapeutic instrument?]

Virtual reality is a relatively new application for rehabilitative neurology, and achieve many successes in assessment and treatment of CNS damages. The Authors describe a prototype computer simulation for virtual environment reconstruction to assess the fundamental living skills of every day dedicated to persons in which CNS injury was occurred.

Ilizarov external fixation in the treatment of comminuted leg fractures

Fifty consecutive comminuted leg fractures were treated by Ilizarov external fixation. Eleven were closed fractures, 37 were Grade II, and 2 were Grade III open fractures. Forty-five fractures healed within 6 months. In 5 fractures the Ilizarov device was removed and healing occurred by intramedullary nailing (2 cases) and decortication (3 cases). The causes of failure were: rapid peroneal union or bone fragment necrosis. Subjective tolerance and fracture stability are limited by septic loosening of the wires requiring frame removal after 6 to 8 months. Excellent results may be obtained (no leg length discrepancy, no angulation, no rotation, no joint stiffness), but the time required for union is long and additional surgery is required.

(2Z,4E)-5-(5,6-dichloro-2-indolyl)-2-methoxy-N-(1,2,2,6,6- pentamethylpiperidin-4-yl)-2,4-pentadienamide, a novel, potent and selective inhibitor of the osteoclast V-ATPase

Optimisation of a novel series of osteoclast ATPase inhibitors led to (2Z,4E)-5-(5,6-dichloro-2-indolyl)-2-methoxy-N-(1,2,2,6,6- pentamethylpiperidin-4-yl)-2,4-pentadienamide (1) that was the most potent compound in an in vitro osteoclast ATPase assay and in human bone resorption assays. Two of the possible geometric isomers have also been prepared and shown to be significantly less potent than 1.

[Computerized tomography false positives in knee medial meniscus injuries. Retrospective study of 400 cases]

PURPOSE

We retrospectively evaluated the diagnostic reliability of high resolution CT (HRCT) in the study of knee joint conditions.

MATERIAL AND METHODS

We reviewed the results of 400 HRCT examinations of the knee performed in 1993 and compared them with arthroscopic findings. The patients were affected with knee pain and the physical findings were insufficient for diagnosis but a sufficient indication for further instrumental tests. CT slices were 1 mm, with .5 mm feed; the images were reconstructed on the coronal and sagittal planes (2 mm thickness and 2 mm gap) with a CT Sytec 3000 unit (GE Systems, Milwaukee, WI, USA).

RESULTS

The patients positive for meniscal fracture were submitted to arthroscopy and operated on if positive arthroscopically. We had 164 surgical cases even though the meniscus was damaged in 236 cases. CT was negative in 16 of 164 surgical cases. The meniscal injury was demonstrated with both CT and arthroscopy in 236 cases; there were 8 false positives and 32 questionable cases. In the latter, arthroscopy showed 24 cases of meniscal degeneration and 8 horizontal fractures. Diagnostic accuracy was 96%. CT showed the 8 false positives as radial injuries of the free margin, but in fact they were false images caused by a normal fold which increases in knee valgus.

DISCUSSION AND CONCLUSIONS

HRCT is more reliable than conventional CT (diagnostic accuracy: 96% vs 85-90%) and MRI (90% reliable). The use of thin slices also permitted to show that a meniscal tissue interruption on the radial margin is not referrable to fracture, as indicated also in the recent literature, but to a normal fold.

Synthesis and structure-activity relationships of bafilomycin A1 derivatives as inhibitors of vacuolar H+-ATPase

The macrolide antibiotic bafilomycin A1 is a highly potent and selective inhibitor of all the vacuolar ATPases (V-ATPases). With the aim of obtaining novel analogues specific for the osteoclast subclass of vacuolar ATPase, 31 derivatives of bafilomycin A1 were synthesized and tested for their ability to inhibit differentially the V-ATPase-driven proton transport in membrane vesicles derived from chicken osteoclasts (cOc) and bovine chromaffin granules (bCG). Although none of the new analogues were more potent than the parent compound, the obtained data provided a significant amount of information about the structural requirements for the inhibitory activity of bafilomycin A1. The different effects of a few analogues on the two enzymes could also suggest the possibility of a selective modulation of the V-ATPases in different tissues.

5-(5,6-Dichloro-2-indolyl)-2-methoxy-2,4-pentadienamides: novel and selective inhibitors of the vacuolar H+-ATPase of osteoclasts with bone antiresorptive activity

The vacuolar H+-ATPase (V-ATPase), located on the ruffled border of the osteoclast, is a proton pump which is responsible for secreting the massive amounts of protons that are required for the bone resorption process. With the aim to identify new agents which are able to prevent the excessive bone resorption associated with osteoporosis, we have designed a novel class of potent and selective inhibitors of the osteoclast proton pump, starting from the structure of the specific V-ATPase inhibitor bafilomycin A1. Compounds 3a-d potently inhibited the V-ATPase in chicken osteoclast membranes (IC50 = 60-180 nM) and were able to prevent bone resorption by human osteoclasts in vitro at low-nanomolar concentrations. Notably, the EC50 of compound 3c in this assay was 45-fold lower than the concentration required for half-maximal inhibition of the V-ATPase from human kidney cortex. These results support the validity of the osteoclast proton pump as a useful molecular target to produce novel inhibitors of bone resorption, potentially useful as antiosteporotic agents.

Neuronal apoptosis in rats is accompanied by rapid impairment of cellular respiration and is prevented by scavengers of reactive oxygen species

Apoptosis of cerebellar granule cells induced by potassium withdrawal is accompanied by a very rapid decrease in both cell and mitochondrial respiration supported by glucose and succinate, respectively. The respiratory control ratio, which is an index of oxidative phosphorylation and therefore reflects the ability of mitochondria to produce ATP, is reduced by 50% within the first 2 h after the beginning of apoptosis, insulin-like growth factor I (IGF-I), actinomicin D or cycloheximide, previously reported to inhibit apoptosis, fully prevent the impairment of cellular respiration while scavengers of reactive oxygen species partially inhibit apoptosis and restore cellular respiration.

Fumarate permeation in normal and acidotic rat kidney mitochondria: fumarate/malate and fumarate/aspartate translocators

In order to gain some insight into the fate of fumarate synthesised in the cytosol in the purine nucleotide cycle and in amino acid catabolism, the capability of both rat kidney mitochondria and acidotic rat kidney mitochondria to take up either externally synthesised, via adenylsuccinate lyase, or added fumarate in exchange with intramitochondrial malate or aspartate was tested by means of both spectrophotometric and isotopic techniques. The appearance of either malate or aspartate caused by the presence of fumarate was revealed outside normal and acidotic mitochondria by using specific substrate detecting systems. Consistently, externally added fumarate was found to cause efflux of either [14C]-malate or [14C]-aspartate from loaded mitochondria. The occurrence in rat kidney mitochondria of two separate translocators, i.e., fumarate/malate and fumarate/aspartate carriers, is shown in the light of saturation kinetics and the different inhibitor sensitivity. The fumarate/aspartate antiporters found in normal and acidotic mitochondria appear to differ from each other.

Glutamate stimulates 2-deoxyglucose uptake in rat cerebellar granule cells

Although glutamate is the most widely used excitatory neurotransmitter in mammalian brain a prolonged exposure of neurons to this amino acid causes their degeneration and death, an event also referred to as excitotoxicity. Since one of the earliest events of excitotoxicity is an impairment of energy metabolism, we have assessed whether such damage is due to a concomitant alteration of glucose uptake in rat cerebellar granule cells. We report that glutamate rather than inhibiting actually activates glucose uptake in a time- and temperature-dependent fashion and that this effect is completely blocked by MK-801, a specific inhibitor of glutamate receptors of the NMDA type. Moreover, while the rate of glucose uptake is constant between 2 DIV and 10 DIV, the extent of glutamate-triggered increase above the basal level is undetectable at 2 DIV and becomes progressively higher with days of incubation in cultures, in a fashion overlapping the appearance of functionally active glutamate receptors. The action of this excitatory amino acid is also mimicked, to various extents, by other glutamate agonists such as kainate, NMDA and quisqualate. The glutamate stimulation of glucose uptake occurs in the same range of concentrations as those necessary to cause neuronal death. These findings are discussed in the light of the possible metabolic mechanism responsible of such activation and in connection with previous similar studies performed on glial or mixed glial-neuronal cultures, whereby the stimulating action of glutamate is achieved via alternate pathways not involving glutamate receptors.