Antiinflammatory agents: new series of N-substituted amino acids with complex pyrimidine structures endowed with antiphlogistic activity

A series of N-methyl-N-pyrimidin-2-yl glycines 2a-e, having the pyrimidine ring fused with a cyclohexane [N-methyl-N-(5,6,7,8-tetrahydroquinazolin-2-yl)glycine], cyclohexene [N-methyl-N-(5,6-dihydroquinazolin-2-yl)glycine], 1,2,3,4-tetrahydronaphthalene [N-methyl-N-(5,6-dihydrobenzo[e]quinazolin-2-yl)glycine], benzopyrane [N-methyl-N-(5-phenyl-5H-[1]benzopyrano[4,3-d]pyrimidin-2-yl)glyci ne] and benzothiopyrane [N-methyl-N-(5H-[1]benzothiopyrano[4,3-d]pyrimidin-2-yl)glycine] ring, was prepared and tested for antiinflammatory activity. With the same purpose a number of N-5H-[1]benzopyrano[4,3-d]pyrimidin-2-yl substituted amino acids 3a-e, having a different chain length and branching were also synthesized and tested. All the described products 2 and 3 showed an appreciable antiphlogistic activity, particularly 2b and 2c.

Cardiotoxicity of doxorubicin: effects of 21-aminosteroids

The purposes of this study were to investigate in vivo the effects of two lazaroids,U-74389G (21-[4-(2,6-di-1-pyrrolidinyl-4-pyrimidinyl)-1-piperazinyl]-pregna-1,4,9 (11)-triene-3,20-dione (2)-2-butenenedionate) and U-83836E (-)-2-[[4-(2,6-di-1-pyrrlidinyl-4-pyrimidinyl)-1-piperazinyl]methy l]-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol, dihydrochloride against the cardiotoxicity induced by doxorubicin in rat and the mechanisms underlying such a toxicity. Doxorubicin (DXR) administered intraperitoneally (5 mg/kg 4 times per week for 1 week) induced significant decrease of body weight, ECG alterations and 100% mortality. The lazaroids used in this study did not protect from DXR-induced cardiotoxicity. Our results showed that the compound U-74389G delayed, but did not reduce DXR-induced mortality, and did not prevent body weight loss and ECG changes. The compound U-83836E was unable to modify any toxic effects induced by DXR. These data indicate that oxygen free radicals and the subsequent increase in intracellular calcium are only steps of DXR progressive general toxicity that leads to cardiac injury. In conclusion, we propose that the 21-aminosteroids, potent inhibitors of membrane lipid peroxidation, alone are not enough to protect from DXR toxic effects.

Research on heterocyclic compounds, Part 40. 2-Phenylimidazo[1,2-a]pyridine-3-carboxylic acid derivatives: synthesis and antiinflammatory activity

A series of 2-phenylimidazo[1,2-a]pyridine-3-carboxylic esters, acids, and amides were synthesized and pharmacologically tested in order to evaluate their antiinflammatory and analgesic activity and their ulcerogenic action on the gastro-intestinal tract. The most active member of this series of compounds was found to be 6-methyl-2-phenylimidazo[1,2-a]pyridine-3-carboxylic acid (5c).

Preparation of new 5-aroylamino substituted 3-nicotinoyl/isonicotinoyl-1,3,4-thiadiazol-2(3H)-ones with anti-inflammatory activity

A series of 1,3,4-thiadiazol-2(3H)-ones (2a-j) with a nicotinoyl/isonicotinoyl group in position 3 and an aroylamino substituent in position 5 of the ring was prepared and evaluated for antipyretic and anti-inflammatory activities. All the title compounds and in particular 2e, 2i and 2j exhibited anti-inflammatory activity and were devoid of antipyretic properties.

Synthesis of angelicin heteroanalogues: preliminary photobiological and pharmacological studies

A series of angelicin heteroanalogues, in which the furan was replaced by thiophene or a 1-substituted pyrazole moiety, was synthesised in order to obtain potential therapeutic agents with antiproliferative and/or other biological activities. In general, the antiproliferative activity of the new thioangelicin, tested in different biological substrates, appeared to be higher than that of the angelicin, the natural parent compound, but lower than that of 8-MOP, the furocoumarin ordinarily used in PUVA therapy and photopheresis. Thioangelicin 6 induced strong inhibition of T2 bacteriophage infectivity and was able to significantly repress the DNA synthesis in Ehrlich ascites cells and the clonal growth in HeLa cells. The pyrazolocoumarins did not show any noticeable effect upon UVA irradiation in all the biological systems considered. All the new angelicin heteroanalogues appeared to be free of the known phototoxicity of furocoumarins on the skin. The pyrazolocoumarins have also been tested as anti-inflammatory, analgesic, antipyretic, local anaesthetic, anti-arrhythmic and platelet anti-aggregating agents by standard procedures. In this class of derivatives, 10a showed good anti-inflammatory and antipyretic properties, while 9a and 11a showed significant local anaesthetic activity.

Synthesis and anti-inflammatory activity of esters derived from 5-aryl-1,2-dihydro-2-(2-hydroxyethyl)-3H-1,2,4-triazole-3-thiones

Some aliphatic and aromatic esters 2a-l were prepared starting from 5-aryl-1,2,4-triazoline-3-thiones bearing a 2-hydroxyethyl chain in position 2. The title compounds were evaluated for antipyretic and anti-inflammatory activities. Nearly all derivatives and in particular 2f, 2h, 2k exhibited antiphlogistic properties but were lacking in antipyretic activity.

Eps8, a tyrosine kinase substrate, is recruited to the cell cortex and dynamic F-actin upon cytoskeleton remodeling

Eps8 is a recently identified substrate of receptor and nonreceptor tyrosine kinases implicated in the control of cell proliferation. To investigate potential functions of Eps8, its intracellular localization has been examined in several cell types. In cycling fibroblasts immunolabeling with antibodies to Eps8 reveals a punctate pattern within the perinuclear region and staining of motile peripheral cell extensions and cell-cell contact regions. Stimulation of quiescent Swiss 3T3 fibroblasts with serum induces a striking reorganization of the actin cytoskeleton which is accompanied by the enrichment of Eps8 and cortactin in membrane ruffles and lamellipodia. A similar accumulation of Eps8 to membrane ruffles is observed in cells treated with phorbol esters, which also induce marked changes of the F-actin cytoskeleton. The localization of Eps8 at the cell cortex is largely independent from the binding of Eps8 to an EGFR/ErbB-2 chimeric receptor. Moreover, fractionation studies reveal that a portion of the Eps8 molecules present in the cell periphery, unlike cortactin and the receptor, is resistant to mild extraction with detergent. Upon cellular transformation by the tyrosine kinase v-Src, a pool of Eps8 is recruited to newly formed specialized regions of the cytoskeleton, such as actin bodies in terminally differentiated myotubes and podosomes in fibroblasts, where cortactin and a variety of cytoskeletal proteins are also found. Extraction with Triton X-100 preserves the association of Eps8 to podosomes and leaves the majority of the v-Src tyrosine-phosphorylated Eps8 in the detergent-resistant fraction. The observed recruitment of Eps8 to highly dynamic cytoskeletal structures of normal and transformed cells suggests that Eps8 may play a role in the reorganization of the cytoskeleton, perhaps acting as a docking site for other signaling molecules.

[Intensive hospital monitoring of adverse reactions to benzodiazepines and neuroleptic agents]

BACKGROUND

The main aims of the programme were to highlight the incidence of adverse reactions to the drugs monitored and to define the risk/benefit ratio taking account of the main physiological and physiopathological variations of patients. This paper reports the results of the programme regarding to adverse effects correlated to the use of some psychiatric drugs (benzodiazepines and neuroleptics).

METHODS

A total of 73 records were compiled for 64 patients treated with benzodiazepines and/or neuroleptics.

RESULTS

A very high mean incidence of adverse events was documented (48%) without any severe undesirable effects. 92% of patients treated with neuroleptics reported adverse events. Haloperidol, which caused adverse effects in 80% of patients, revealed mild or moderate forms of parkinsonism (15%), spasm (15%), rigidity (10%), akathisia (5%), reversible postural hypotension (10%), temporary reduction of the visual field (10%), delayed menstrual flow (5%), xerostomia (10%), excessive sweating (10%) and sialorrhea (10%). All the patients treated with clozapine showed adverse effects including postural hypotension (29%), persistent tachycardia (14%), sialorrhea (29%), excessive sweating (14%) and akathisia (14%). Spasms (25%), rigidity (25%) and akathisia (25%) were correlated to the use of clothiapine, whereas postural hypotension was referred to clopenthixol. 44% of patients treated with benzodiazepines showed undesired effects. 20% of those taking chlordemethyldiazepam showed somnolence (33%), sedation (22%) and dysar-thria (44%). Prolonged sedation was observed in 30% of all patients treated with lorazepam. Prazepam was correlated with adverse effects in 75% of cases. No adverse event was documented with bromazepam.

CONCLUSIONS

A higher incidence of adverse events was documented than literature data. Further periods of intensive monitoring will be required to obtain a greater quantity of data from the intensive monitoring of adverse events through the MIO '97 programme.

[Hospital intensive monitoring of adverse reactions of ACE inhibitors]

BACKGROUND AND AIMS

Angiotensin II converting enzyme (ACE) inhibitors represent one of the most important pharmacological instruments for the treatment of arterial hypertension and are currently also used for other cardiovascular indications. The actions of ACE-inhibitors mainly depends on blocking the ACE enzyme in the renin-angiotensin-aldosterone system. However, the ACE enzyme also has a kinase activity. The inhibition of this enzyme may also cause an accumulation of tissue mediators (bradykinin) responsible for a number of adverse reactions.

METHODS

An intensive hospital monitoring programme of adverse reactions to drugs, known as MIO[symbol: see text]'96, was carried out by the Centre of Pharmacoepidemiology of the Faculty of Medicine and Surgery at the Second University of Naples during the period 25 March-18 April 1996. The main aims of the programme were to highlight the incidence of adverse reactions to the drugs monitored and the definition of the risk/benefit ratio taking account of the main physiological and pathophysiological variations of patients. This paper reports the results of the programme of adverse effects correlated to the use of ACE-inhibitors. A total of 175 records were compiled for 105 patients receiving antihypertensive treatment with a number of ACE-inhibitors (captopril, enalapril, lisinopril); a very high mean incidence of adverse events was documented (22%) without any severe undesirable effects.

RESULTS

The following adverse events were documented (the cumulative incidence is given in brackets): dysgeusia (17%), flush (8%), headache (33%), exanthema (17%), diarrhoea (8%), vertigo (8%), xerostomia (8%). Coughing was not reported in any patient.

CONCLUSIONS

Further periods of intensive monitoring will be required to obtain a greater quantity of data from the Intensive Monitoring of adverse events through the MIO[symbol: see text]'97 programme.

Synthesis of 1-methyl-4-(N-aroyl)-piperidinamides with anti-inflammatory and analgesic activities

Two series of 1-methyl-4-(N-aroyl)-piperidinamides were synthesized and evaluated for their anti-inflammatory and analgesic properties, as well as for their gastrointestinal irritation liability. A non-aromatic derivative, 1-methyl-4-(N-cyclohexanoyl)-piperidinamide, was synthesized and evaluated in order to obtain a more exhaustive knowledge of the structure-activity relationship.

Inhibition of frog skeletal muscle sodium channels by newly synthesized chiral derivatives of mexiletine and tocainide

To search for potent use-dependent blockers of skeletal muscle sodium channels as potential antimyotonic agents, the actions of newly synthesized chiral analogs of mexiletine and tocainide were tested in vitro on sodium currents of single fibers of frog semitendinosus muscle by vaseline-gap voltage clamp method. The effect of each drug on the maximal peak Na+ transient (I(Na) max) was evaluated as both tonic and use-dependent block by using infrequent depolarizing stimulation and trains of pulses at 2-10 Hz frequency, respectively. The mexiletine analog 3-(2,6-dimethylphenoxy)-2-methylpropanamine (Me2), having an increased distance between the phenyl and the amino groups, was less potent than mexiletine in producing a tonic block but produced a remarkable use-dependent block. In fact, the half-maximal concentration (IC50) for tonic block of S(-)-Me2 was 108 microM vs. 54.5 microM of R(-)-mexiletine, but the IC50 was 6.2 times lowered by the 10 Hz stimulation with respect to the 2.4 fold decrease observed with mexiletine. The R(-)-mexiletine and the S(-)-Me2 were about twofold more potent than the corresponding enantiomers in producing a tonic block, but the stereoselectivity attenuated during use-dependent blockade. The more lipophilic 2-(4-chloro-2-methylphenoxy)-1-phenylethylamine (Me1), presently available as raceme, produced a potent and irreversible tonic block of the sodium currents with an IC50 of 29 microM, but had a less pronounced use-dependent inhibition, with a 1.9 fold decrease of the IC50 at 10 Hz. The R(-) isomer of 2',6'-valinoxylidide (To1), a tocainide derivative with an increased hindrance on the chiral carbon atom, was twofold (IC50 = 209 microM) and tenfold (IC50 = 27.4 microM) more potent than R(-)-tocainide in tonic and use-dependent block, respectively. Tocainide was almost devoid of stereoselectivity, whereas the eudismic ratio of To1 [(IC50 S(+)-To1/IC50 R(-)-To1] was 1.7. As for mexiletine and Me2, the stereoselectivity of To1 was the weaker the higher the frequency of stimulation. The cyclic pyrrolo-imidazolonic tocainide analog To2 produced a small tonic block at 500 microM, and 1 min stimulation at 10 Hz was needed to show up a 50% block of I(Na) max. All the compounds produced a left-shift of the steady-state inactivation curve correlated positively with the extent of use-dependent inhibition, with the exception of the cyclic To2 that acted as an open-channel blocker. The highly use-dependent blockers Me2 and To1 might be promising drugs to solve high frequency discharges of action potentials typical of myotonic muscles. Concomitantly the high potency of Me1 and the open-channel block exerted by To2 can represent important features to get selective blockers for skeletal muscle sodium channels.

Comparison of three restriction endonucleases in IS1245-based RFLP typing of Mycobacterium avium

IS1245-based restriction fragment length polymorphism (RFLP) analysis has been proposed recently for molecular typing of Mycobacterium avium isolates. As there is no standardised method with respect to the optimal restriction enzyme, three restriction endonucleases were tested for analysis of 17 human isolates. The restriction endonucleases, selected on the basis of the physical maps of IS1245 and of the highly homologous IS1311, were BsaAI, that cleaves IS1245, PvuII, that cleaves IS1311, and NruI, that cleaves both IS1245 and IS1311. All the restriction endonucleases yielded polymorphic and complex RFLP patterns. However, BsaAI- and NruI-generated bands were more evenly distributed and easier to detect than PvuII-generated bands, most of which clustered in a narrow zone of the fingerprint. In some cases, DNA digestion with BsaAI or NruI yielded probe-specific restriction fragments of molecular size lower than expected. Moreover, digestion with NruI, which was expected to generate the highest numbers of bands in all the isolates, yielded fewer bands than were obtained with BsaAI or PvuII in 14 and 5 isolates, respectively. These findings might suggest the existence of unidentified IS1245-related insertion element(s) in M. avium isolates. Computer analysis of the IS1245-based RFLP patterns of M. avium isolates showed that the restriction endonucleases were capable, although with minor differences, of defining distinct banding patterns and clusters of identical or highly related isolates, thus confirming IS1245-based RFLP analysis as a useful technique for epidemiological studies.

Regulation of the tyrosine kinase substrate Eps8 expression by growth factors, v-Src and terminal differentiation

SH3-containing proteins are involved in signal transduction by a number of growth factor receptors and in the organization of the cytoskeleton. The recently identified Eps8 protein, which contains an SH3 domain, is coupled functionally and physically to the EGFR and is tyrosine phosphorylated by this receptor and other receptors as well. Here, we examined the regulation of eps8 expression in response to mitogenic or differentiative signals. We show that Eps8 is expressed at low levels in resting fibroblasts, but its expression is strongly induced during activation by serum, phorbol esters and the v-src oncogene. Conversely, expression of Eps8, but not of other EGFR substrates such as Shc or Eps15, is virtually extinguished in non-proliferating, terminally differentiated murine myogenic cells. The putative role of Eps8 protein as a v-Src substrate was analysed in murine fibroblasts and in quail myogenic cells expressing a temperature-sensitive variant of the tyrosine kinase. Tyrosine phosphorylation of Eps8 was detected only at the permissive temperature. A non-myristylated, transformation-defective mutant of v-Src did not phosphorylate Eps8, whereas it phosphorylated Shc. Together, these findings indicate that Eps8 may be a critical substrate of v-Src. They further establish Eps8 as an example of a signal transducer whose expression senses the balance between growth and differentiation and might, therefore, be involved in the determination of the phenotype.

DNA restriction fragments length polymorphism of Mycobacterium tuberculosis isolates in Pisa, Italy

A total of 60 Mycobacterium tuberculosis strains isolated in the area of Pisa, Italy, over a period from April 1993 to December 1995, were analyzed for the IS6110-based restriction fragments length polymorphism (RFLP). Isolates were found to show a great heterogeneity and only few isolates shared identical DNA banding patterns. In particular, 55 distinct IS6110 patterns were found (average number of isolates per pattern: 1.09) and only 9 strains (15%) occurred in 4 clusters of 2-3 identical clones. Computer analysis of genetic similarities among the strains revealed a family of 17 isolates including the clustered clones implicated in recently acquired infections. No correlation was found between the RFLP DNA patterns of the isolates and drug susceptibility. Of the 5 isolates from immigrants only one showed abnormal DNA fingerprinting. Our data indicate that the patterns of M. tuberculosis isolates in Pisa area are comparable to those of countries with low-prevalence TB and that a low level of TB transmission occurs in this area.

N-arylsubstituted-1-aryl-3,4-diphenyl-5-pyrazole amines with analgesic and antiarrhythmic properties

A series of N-aryl substituted-1-aryl-3,4-diphenyl-5-pyrazole amines was synthesized and evaluated for antiinflammatory, antihypertensive and platelet antiaggregating activities. Several of them were found to exhibit a significant analgesic and antiarrhythmic activity.

Metal fume fever: characterization of clinical and plasma IL-6 responses in controlled human exposures to zinc oxide fume at and below the threshold limit value

Results from animal and preliminary human exposure studies have called into question whether the 5 mg/m3 8-hour time-weighted average threshold limit value (TLV) for zinc oxide fume is sufficient to protect workers against metal fume fever. The objectives of this study were to determine the clinical effects of exposures to low concentrations of zinc oxide and to ascertain whether these exposures elevated circulating levels of specific cytokines, which could account for the symptoms of the metal fume fever syndrome. Thirteen resting naive subjects inhaled, on separate days, air and 2.5 and 5 mg/m3 of furnace-generated zinc oxide fume for 2 hours. Subjects recorded symptoms and temperature and had blood drawn before and after each exposure. The mean (+/- SE) maximum rise in oral temperature at 6 to 12 hours after exposure was 1.4 +/- 0.3 degrees F after 5 mg/m3, compared with 0.6 +/- 0.5 degrees F after air exposure (P < 0.05). Mean temperature was also elevated after exposure to 2.5 mg/m3 zinc oxide (1.2 +/- 0.3 degrees F). In a parallel fashion, plasma levels of interleukin 6 (IL-6), a pyrogen, were significantly elevated after exposure to 5 mg/m3 zinc oxide. Mean IL-6 values (pg/mL) at pre-exposure and at 3 and 6 hours post-exposure were 1.9 (+/- 0.6), 2.8 (+/- 0.7), and 2.9 (+/- 0.6), respectively, on the air day and 1.6 (+/- 0.6), 4.4 (+/- 1.2), and 6.4 (+/- 1.1) on the 5 mg/m3 zinc oxide day. Zinc oxide exposure did not significantly affect plasma levels of tumor necrosis factor. Total symptom scores peaked 9 hours after the 5 mg/m3 zinc oxide exposure. Myalgias, cough, and fatigue were the predominant symptoms reported. Inhalation of zinc oxide for 2 hours at the current TLV of 5 mg/m3 produces fever and symptoms along with elevation in plasma IL-6 levels.

Synthesis of 6-thiosubstituted 5-ethoxycarbonyl-1,3-diphenyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-ones, 6-substituted 5-hydroxy-1,3-diphenyl-2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones and their esters with local anesthetic, antiarrhythmic, antiinflammatory and analgesic activities

The synthesis of 6-thiosubstituted 5-ethoxycarbonyl-1,3-diphenyl-2-thioxo-2,3-dihydropyrimidin- 4(1H)-ones 3, and of 6-substituted 5-hydroxy-1,3-diphenyl-2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones 5 and their esters 6 is described. These derivatives were prepared in order to evaluate the influence on the pharmacological profile of alkyl substituents bearing polar/hydrophilic functionalities at an enethiol substructure as in compounds 3 or to assess the effects arising from the incorporation of the sulfur atom in a thiophene moiety as in thienopyrimidinones 5 and 6 in comparison with a series of 5-substituted 6-acylthio-1,3-diphenyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-ones 1c,d, previously described. Preliminary screenings suggest that all tested compounds maintained or even increased the local anesthetic activity, but failed in the platelet antiaggregating activity; on the other hand, antiarrhythmic and antiinflammatory activity was preserved in some esters 6.

Synthesis of amides with anti-inflammatory and analgesic activities

A series of N-Aroyl-cyclohexyl- and cyclohexenylamides 3- or 4-methylsubstituted were synthesized and evaluated for their anti-inflammatory and analgesic potencies, and gastrointestinal irritation liability. One compound, N-benzoyl-4-methyl-cyclohexylamide 6a, possessed an anti-inflammatory activity comparable to that of indomethacin.

2-Aryl-6-methyl-3-phenylamino-6,7-dihydropyrano[4,3-c]pyrazol-4(2H)-ones with analgesic activity

A series of 2-aryl-6-methyl-3-phenylamino-6,7-dihydropyrano[4,3-c]pyrazol-4(2H )-ones were prepared and tested for antiinflammatory, analgesic, antipyretic, antiarrhythmic, antihypertensive and platelet antiaggregating activities. All of them showed an appreciable level of analgesic activity in mice.

Evidence of nosocomial transmission of tuberculosis among AIDS patients by DNA fingerprinting

DNA restriction fragment length polymorphism (RFLP) analysis was performed on Mycobacterium tuberculosis isolates from patients in the human immunodeficiency virus (HIV) Unit of a community hospital. It was found that M. tuberculosis isolates from two patients with AIDS shared an identical RFLP pattern. Such a fingerprint was not found in M. tuberculosis isolates from any of 40 HIV-negative patients hospitalized in different Units over the same period, assumed as representative of the strains present in the community, thus ruling out that the isolates from the two AIDS patients might match because only a few strains were present in the community. Clinical records of the two AIDS patients showed an 8-day concomitant hospitalization period in the same ward during which one of the two patients showed active tuberculosis; the second patient developed active tuberculosis less than two months later. These findings strongly support the possibility of nosocomial transmission of tuberculosis.

Synthesis and pharmacological activity of some N,N-disubstituted 1-amino-2-phenyl-3H,12H-naphtho[1,2-b]pyrano[2,3-d]pyran-3-ones

The synthesis of some N,N-disubstituted 1-amino-2-phenyl-3H,12H-naphtho[1,2-b]pyrano[2,3-d]pyran-3-ones 4, by reaction of phenylchloroketene with a series of N,N-disubstituted 3-aminomethylene-2,3-dihydro-4H-naphtho[1,2-b]pyran-4-ones, followed by dehydrochlorination in situ of the primary adducts with DBN, is described. Some compounds 4 showed antiarrhythmic and analgesic activities.

Synthesis and SAR study of imidazo[2,1-b]benzothiazole acids and some related compounds with anti-inflammatory and analgesic activities

Some (un)substituted imidazo[2,1-b]benzothiazole carboxylic or acetic acids and some related compounds, i.e. imidazo[2,1-b]naphthol[2,1-d]thiazole, 4H-imidazo[2,1-c][1,4]benzothiazine, 4,5-dihydroimidazo[2,1-d][1,5]benzothiazepine carboxylic and acetic acids were synthesized and tested in vivo in order to study the structure-activity relationships (SAR) of their antiinflammatory and analgesic activities. Pharmacological assays confirmed the interest of this class of compounds as potential antiinflammatory and analgesic drugs with low side effects.

Remodeling of cytoskeleton and triads following activation of v-Src tyrosine kinase in quail myotubes

To study the cellular signals underlying the regulatory mechanisms involved in maintenance of sarcomeric integrity, we have used quail skeletal muscle cells that reach a high degree of structural maturation in vitro, and also express a temperature-sensitive mutant of the v-Src tyrosine kinase that allows the control of differentiation in a reversible manner. By immunofluorescence and electron microscopy we show that v-Src activity in myotubes leads to an extensive cellular remodeling which affects components of the sarcomeres, the cytoskeleton network and the triad junctions. We have previously shown that activation of v-Src causes a selective dismantling of the I-Z-I segments coupled to the formation of aggregates of sarcomeric actin, alpha-actinin and vinculin, called actin bodies. We now show that intermediate filaments do not participate in the formation of actin bodies, while talin, a component of costameres, does. The I-Z-I segments are completely dismantled within 24 hours of v-Src activity, but the A-bands persist for a longer time, implying distinct pathways for the turnover of sarcomeric subdomains. Immunofluorescence labeling of markers of the triad junctions demonstrates that the localization of the alpha 1 subunit of the dihydropyridine receptor is disrupted earlier than that of the ryanodine receptor after tyrosine kinase activation. Furthermore, the location of junctional sarcoplasmic reticulum and transverse tubule membranes is maintained in myotubes in which the I-Z-I have been removed and the regular disposition of the intermediate filaments is disrupted, supporting a role for sarcoplasmic reticulum in the proper positioning of triad junctions. Altogether these results point to a tyrosine kinase signaling cascade as a mechanism for selectively destabilizing sarcomere subdomains and their tethering to the cytoskeleton and the sarcolemma.

[Widened forwarding total laryngectomy ("squared laryngectomy"). Hints of surgical techniques and personal experience]

Primitive T4 laryngeal neoplasms with anterior invasion and neoplasm recurring after partial and subtotal intervention often invade the soft prelaryngeal tissues and in these cases the neoplastic illness can be no longer be controlled be "organ surgery". The widened forwarding total laryngectomy, "squared" or "carrè" laryngectomy according to some Authors of French School, is a surgical procedure not "on an organ" but "in an area" or "region" which proposes to delete, in one step, the larynx, the bone hyoid, the fasciae and the prelaryngeal muscles, the thyroid gland and, if necessary, a more or less large quantity of anterior cervical skin. If the removal involves a vast cutaneous area, it is necessary to mend the loss of substance by wrapping around a miocutaneous flap of pectoralis mayor muscle. In the last five years, 4 male patients, between 48 and 73 years, were treated with widened forwarding total laryngectomy. They were all carriers of epidermoid laryngeal carcinomas with various degrees of differentation: primitive in one patients, recidivist after performance of partial (cordectomy) and subtotal (two Labayle) surgery in the other three patients. In the only case of T4 primitive laryngeal neoplasm it was necessary to carry out a functional neck dissection bilaterally. Loss of substance always required the use of a miocutaneous flap of pectoralis mayor muscle except in one patient in which the removal of the prelaryngeal tissues was limited and therefore it was possible to make a direct seam. We always completely removed the thyroid gland, the prelaryngeal muscular system and skin of the preceding stomy (in the Labayle) sparing, on the other hand, the hyoid bone. Only one patient, who died due to recurrence a year after surgery, underwent complemental percutaneous radiotherapy. At present, three patients are alive and NED: one after 5 years, the others are in excellent conditions although the follow-up is still brief. According to our experience, we can affirm that in selected cases, after an accurate general evaluation of the patient (exclusion of distant metastases, preparation from a metabolic and psychological point of view) a widened forwarding total laryngectomy is a valid procedure since surgery (together with other complementary therapies), is still today the best treatment in forms with anterior evolution.