Benzoindoloquinolines interact with DNA tetraplexes and inhibit telomerase

Telomeric G-rich single-stranded DNA can adopt a G-tetraplex structure which has been shown to inhibit telomerase activity. We have examined benzoindoloquinolines derivatives for their ability to stabilize an intramolecular G-quadruplex. The increase in T(m) value of the G-quadruplex was associated with telomerase inhibition in vitro.

Interaction of an acridine dimer with DNA quadruplex structures

The reactivation of telomerase activity in most cancer cells supports the concept that telomerase is a relevant target in oncology, and telomerase inhibitors have been proposed as new potential anticancer agents. The telomeric G-rich single-stranded DNA can adopt an intramolecular G-quadruplex structure in vitro, which has been shown to inhibit telomerase activity. The C-rich sequence can also adopt a quadruplex (intercalated) structure (i-DNA). Two acridine derivatives were shown to increase the melting temperature of the G- quadruplex and the C-quadruplex at 1 microM dye concentration. The increase in Tm value of the G-quadruplex was associated with telomerase inhibition in vitro. The most active compound, "BisA", showed an IC(50) value of 0.75 microM in a standard TRAP assay.

Backbone dynamics of Tet repressor alpha8intersectionalpha9 loop

A set of single Trp mutants of class B Tet repressor (TetR), in which Trp residues are located from positions 159 to 167, has been engineered to investigate the dynamics of the loop joining the alpha-helices 8 and 9. The fluorescence anisotropy decay of most mutants can be described by the sum of three exponential components. The longest rotational correlation time, 30 ns at 10 degrees C, corresponds to the overall rotation of the protein. The shortest two components, on the subnanosecond and nanosecond time scale, are related to internal motions of the protein. The initial anisotropy, in the 0.16-0.22 range, indicates the existence of an additional ultrafast motion on the picosecond time scale. Examination of physical models for underlying motions indicates that librational motions of the Trp side chain within the rotameric chi(1) x chi(2) potential wells contribute to the picosecond depolarization process, whereas the subnanosecond and nanosecond depolarization processes are related to backbone dynamics. In the absence of inducer, the order parameters of these motions, about 0.90 and 0.80 for most positions, indicate limited flexibility of the loop backbone. Anhydrotetracycline binding to TetR induces an increased mobility of the loop on the nanosecond time scale. This suggests that entropic factors might play a role in the mechanism of allosteric transition.

Trp scanning analysis of Tet repressor reveals conformational changes associated with operator and anhydrotetracycline binding

We analysed the conformational states of free, tet operator-bound and anhydrotetracycline-bound Tet repressor employing a Trp-scanning approach. The two wild-type Trp residues in Tet repressor were replaced by Tyr or Phe and single Trp residues were introduced at each of the positions 162-173, representing part of an unstructured loop and the N-terminal six residues of alpha-helix 9. All mutants retained in vivo inducibility, but anhydrotetracycline-binding constants were decreased up to 7.5-fold when Trp was in positions 169, 170 and 173. Helical positions (168-173) differed from those in the loop (162-167) in terms of their fluorescence emission maxima, quenching rate constants with acrylamide and anisotropies in the free and tet operator-complexed proteins. Trp fluorescence emission decreased drastically upon atc binding, mainly due to energy transfer. For all proteins, either free, tet operator bound or anhydrtetracycline-bound, mean fluorescence lifetimes were determined to derive quenching rate constants. Solvent-accessible surfaces of the respective Trp side chains were calculated and compared with the quenching rate constants in the anhydrotetracycline-bound complexes. The results support a model, in which residues in the loop become more exposed, whereas residues in alpha-helix 9 become more buried upon the induction of TetR by anhydrotetracycline.

Pancreatic regeneration after subtotal distal resection in rats. Effects of bombesin and octreotide by the in vivo bromodeoxyuridine uptake technique

Forty male Wistar rats were randomly allocated to four treatment groups after 90% distal pancreatectomy: group A (control) received saline (0.5 ml subcutaneously); group B received bombesin (BBS; 10 microg/kg intraperitoneally); group C received octreotide (2.5 microg/kg subcutaneously), and group D received BBS and octreotide. All substances were injected three times a day until sacrifice after 28 days. BBS increased pancreas weight (p = 0.003) and DNA synthesis (p < 0.001), as measured by a bromodeoxyuridine nuclear-labeling index (BrdU LI). The simultaneous administration of octreotide significantly decreases the remnant pancreas weight (p = 0.016) as compared to group B rats; however the BrdU LI is not significantly reduced in group D as compared to group B. BBS administration promotes regeneration of the remnant pancreas in terms of hypertrophy and hyperplasia. Although octreotide appears to significantly reduce the pancreatic weight increase induced by BBS, it does not reduce DNA synthesis and cell proliferation.

Structural investigation of Tet repressor loop 154-167: a time-resolved fluorescence study of three single Trp mutants

We have studied the time-resolved fluorescence of three engineered Tet repressor (TetR) mutants bearing a single Trp residue at positions 162, 163, and 165 in the C-terminal part of the loop joining helices 8 and 9. Detailed analysis indicates that, at 20 degrees, the fluorescence decay of each Trp can be described as the sum of three exponential components with lifetimes in the 1-, 3-, and 6-ns range. Emission wavelength and temperature dependence studies are consistent with a model in which these components are due to the existence of three classes of Trp residues non-interconverting on the nanosecond timescale. Within the framework of the rotamer model, the weak temperature dependence of the lifetimes strongly suggests that the secondary structure of the loop, at least in the 162-165 range, is not altered with temperature. The equilibrium between the rotamers is characterized by an enthalpy-entropy compensation effect which strongly suggests the involvement of background structural regions of TetR in the thermodynamics of the process. The very high deltaH degrees and TdeltaS degrees observed (up to 18 kcal/ mol) should reflect the temperature-dependent conformational change of a large part of the protein which would alter the rotamer distribution of the Trp residues. Taken together, our results are consistent with the existence of (at least) two conformations of the loop and suggest a model for loop motion.

[Gangrenous cystitis. Case report]

A rare case of gangrenous cystitis is described. The questions of the incidence of this pathology are discussed, considering its rareness after the antibiotics age. The etiology of this disease is probably multifactorial and it is never possible to identify a unique cause. The gangrenous cystitis doesn't present with any typical symptomatology, out with urinary troubles common to many urologic diseases. Surgery is often performed in emergency without a preoperative defined diagnosis. Surgical treatment has changed with time from a simple bladder cavity draining to the resection of the necrotized bladder wall. In our case a total cystectomy with uretero-ileocutaneostomy, in two times, was performed. This procedure allowed the patient a good quality of life (1 year of follow-up).

[Unusual cause of gastric bleeding: leiomyoma]

The gastric leiomyoma is a rare non-epithelial tumor of the stomach that can either be asymptomatic (autoptical diagnosis) or, on the contrary, suddenly appear with severe gastric hemorrhage. The authors review the literature and report their own experience concerning 6 cases of gastric leiomyoma observed during 5 years. They discuss the clinical presentation, the difficulties of diagnosis and the therapeutic choices.

Effect of octreotide on pancreatic regeneration in rats measured by bromodeoxyuridine uptake

OBJECTIVE

To study the effects of up to 60 days intermittent octreotide on regeneration of rat pancreas stimulated by cholecystokinin after 70% distal resection. DESIGN. Random controlled experimental study.

SETTING

University hospital, Italy.

MATERIALS

60 Male Wistar rats.

INTERVENTIONS

Distal resection of splenic and gastric lobes of pancreas (70% of whole gland). Rats were allocated to three groups (n = 20 in each): group A (control) were given saline solution 0.5 ml; group B were given cholecystokinin 300 ng/kg; and group C were given cholecystokinin 300 ng/kg and octreotide 2.5 micrograms/kg. All substances were injected subcutaneously twice a day until death. Four rats were killed weekly for four weeks, and the remainder at 60 days.

MAIN OUTCOME MEASURES

Increase in weight of the gland as a percentage of the weight of the whole gland, and DNA synthesis measured by bromodeoxyuridine (BrdU) nuclear labelling index.

RESULTS

In the cholecystokinin alone group pancreatic weight had increased significantly on days 21 and 28 (95% confidence intervals (CI) - 13.8 to 12.2 and -44.1 to 19.7, respectively) and the BrdU index had increased significantly at 21 (0.56 to 0.80), 28 (0.26 to 1.3), and 60 (0.09 to 0.51) days compared with the control group. In the group given both cholecystokinin and octreotide the weight was significantly lower than in the cholecystokinin alone group at 21 and 28 days (95% CI - 1.02 to 66.7 and 3.5 to 34.7, respectively) and the BrdU index was significantly lower at 28 days (0.40 to 1.19).

CONCLUSIONS

Octreotide seems to reduce the pancreatic regeneration induced by cholecystokinin in rats after 70% distal resection. To our knowledge this has not previously been shown, and the mechanism must be elucidated further.

[Splenic abscess: case report and review of the literature]

After the observation of a case of splenic abscess the authors make a review of the literature. It is important to note that splenic abscesses are increasing in number because of some particular situations that can help their development. The diagnosis is not always easy and quick, because of the frequent lack of a typical symptomatology, and the later the diagnosis, the worse the prognosis. Besides, classical surgical therapy must be considered for selected cases, a conservative therapy that can be very useful for patients in very poor conditions.

[Solitary ulcer of the rectum]

The authors review their five-year experience of solitary rectal ulcers. A revision of the most recent literature enables them to outline the characteristics of the disease with reference to its epidemiology, anatomopathology and clinical features. The discussion focuses on the problem of treatment which must be based on a thorough and in-depth knowledge of pathogenetic mechanisms. The paper outlines two theories, the hamortomatous one and the so-called mechanical theory involving the hinge valve, which are referred to by most researchers. The question of treatment is then discussed illustrating the possibility of resorting to surgical-type treatment which appears to be the most suitable for the definitive resolution of the problem. But since, at least in the light of the authors' personal experience; the majority of patients belong to an age group in which other pathologies are often present, the medical treatment option appears to be more rational. The re-education of the alvus achieved using suggestions not only of a dietary type but also regarding the behaviour and correct position to assume during defecation appears, at least theoretically, sufficient to obtain a marked improvement. The local application of therapeutical AIDS, if necessary strengthened by the action of drugs taken systemically, brings considerable further benefit to the patient who cannot and/or does not which to undergo surgery.

[Granulosa cell tumor of Abrikossof]

The authors report a case of Abrikossof's tumor that came under their observation. The reappraisal of the literature permits to review on this disorder that was unknown until few years ago. Electronic microscope and immunohistochemical study allowed to recognize the real origin of this tumor. It arises from peripheric nervous tissue particularly from Schwann's cells. This neoplasm must be considered as benign, especially when of small dimensions. In case of rapidly growing or larger than 8 cm forms a widely exeretic surgery and a careful follow-up, because of the possibility of finding tumors in other district of the body.

[Appendicular mucocele. Clinical cases and review of the literature]

The authors report three cases of mucocele of the appendix. They review the literature on this argument and discuss the hypotheses on etiology, pathologic and clinical classification, problems in diagnosis, principles of therapy and prognosis.

Ribosomal protein S6 kinase and protein kinase C activation by epidermal growth factor after temporary renal ischemia

An initial event in cell response to growth factors is the change in the state of phosphorylation of a number of cellular proteins playing a role in cell proliferation. The effects of a single dose of exogenously administered epidermal growth factor (EGF) on renal serine/threonine protein kinases such as ribosomal protein S6 kinase(s) and protein kinase C (PKC) and on [3H]thymidine incorporation into tubule cell nuclei have been studied during the regenerative repair response after temporary renal ischemia in the rat, followed by reperfusion for up to 72 h. During the postischemic reflow, the PKC and S6 kinase activities increased at 24 and 72 h, respectively. EGF anticipated both increases: the PKC at 4 and the S6 kinase(s) at 24 h. Associated with this EGF-induced rise of S6 kinase activity, a significant increase in renal tubule cell proliferation was observed. These studies suggest the presence of a growth factor-activated serine/threonine phosphorylation cascade in the rat kidney participating in the regulation of cell growth during recovery from an ischemic insult.

Human papilloma virus infection and Ki-ras oncogene in paraffin-embedded squamous carcinomas of the cervix

42 paraffin-embedded squamous cervical carcinomas were screened for the presence of human papilloma virus (HPV; 6b, 11, 16, 18) and for activation of the Ki-ras oncogene family by polymerase chain reaction. In 72% of cases we found one or more HPV types, but no mutations of the Ki-ras gene (codon 12-1 and 61-1, 61-2 and 61-3) were found. We conclude that mutations of the Ki-ras oncogene, at the positions analyzed, are not likely to be involved in the events leading to cervical carcinogenesis.

[Primary stones of the common bile duct]

Primary stones can probably form, although rarely, in the common bile duct. The authors report a series of six cases which they considered as primary common duct stone disease and, in order to get more precise information on this problem, they review the literature on the subject. This disease would be caused by the presence of a lithogenic bile which, with a chronic obstruction of the Vater's ampulla, could let lithiasic particles accumulate in the common bile duct. On the basis of this hypothesis and in order to perform a correct procedure that allows easy drainage of the bile to the intestine to the chronic use of litholytic drugs.

[Mondor syndrome. Etiopathogenesis and case report]

The Authors observed and report a case of Mondor's syndrome in a male. In the attempt to identify the real origin in this peculiar thrombophlebitis they reviewed the recent literature. It is apparently impossible to drawn definitive conclusions from the different studies on this subject. Anyway Mondor's syndrome looks suitable for inclusion in the group of jumping thrombophlebitis. Therefore the real cause of the venous accident should be a pathologic situation next to the venous branch where the thrombophlebitis has broken out.

[Tumors of the small intestine. Case reports and comments]

Tumours of the small intestine are extremely rare and have a particularly severe prognosis. The impossibility of making an early diagnosis due to the scarcity of precise symptoms during the early stages of the disease and the lack of safe instrumental tests limits the results of treatment which is essentially surgical. In order to contribute to the study of the disease and improve its prognosis, the authors report the cases which they have observed and review the literature.

Ribosomal protein S6 kinase is activated after folic acid injury and epidermal growth factor administration but not after unilateral nephrectomy in the rat kidney

Following loss of functional renal mass induced by a single parenteral injection of folic acid, the increased proliferation of tubular epithelium to replace injured and necrotic cells was associated with S6 kinase activation and enhanced phosphorylation of this ribosomal protein in vitro, EGF administered 1.5 h after folic acid promoted the phosphorylation of S6 protein and accelerated the regenerative repair process. In contrast, the hypertrophic response of the kidney following uninephrectomy was not associated with S6 kinase activation. The results of this study suggest a close correlation between levels of S6 protein phosphorylation and the degree of cell proliferation in the rat kidney.

[Carcinoid tumor of the appendix]

The authors after briefly outlining the epidemiological and clinical characteristics of the appendiceal carcinoid, report a case observed by them. They discuss the problem concerning the prognosis of this particular tumoral form, and the prognosis which could be more severe than people generally think.

Picotamide protects mice from death in a pulmonary embolism model by a mechanism independent from thromboxane suppression

We have previously characterized the new antiplatelet agent picotamide as a dual thromboxane synthase inhibitor/thromboxane A2 receptor antagonist in human platelets. We have now studied the antithrombotic activity of this drug in a simple animal model of lung platelet thromboembolism in the mouse. Picotamide, given i.p. 1 hr before the thrombotic challenge, protected mice from death caused by the i.v. injection of collagen plus epinephrine in a dose-dependent way; the dose reducing mortality by 50% was 277 mg/kg while for aspirin it was 300 mg/kg. Picotamide was also able to reduce the mortality provoked by the i.v. injection of the stable TxA2 mimetic U46619; BM 13.505, a pure TxA2-receptor blocker, was also effective while aspirin was totally inactive. Picotamide, finally, reduced the lethal consequences of the i.v. injection of a 12.5% suspension of hardened rat red blood cells, a model in which platelets are not involved; aspirin was totally ineffective in this model while nicardipine, a calcium channel blocker, was active. Picotamide did not inhibit the formation of TxB2 in serum at any of the doses tested (100 to 750 mg/kg i.p.) while it did enhance significantly PGI2-synthesis from mice aortae and, even more, from mice lungs. The i.v. administration of picotamide (250 mg/kg 2 min before the thrombotic challenge) lead to a strong inhibition of serum TxB2 (-84.6%) and was associated with a higher antithrombotic effect.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pilonidal sinus: our experience in the surgical treatment by closed method]

The A. describe the essential traits of the "sinus pilonidalis" disease and report the results obtained by surgical therapy and compared their data with literature data. The A. underline the goodness of the "closed method" particularly if a few special tricks are employed.

Ontogeny of CA 125 antigen in pregnancy: immunoradiometric determination in amniotic fluid and immunohistochemical localization in fetal membranes

CA 125 antigen was measured in amniotic fluid, maternal blood, cord blood, and fetal urine by a commercially available immunoradiometric assay kit. The amniotic fluid was obtained from 99 normal pregnancies at various gestational ages. The mean antigen levels were 29,676, 3350, and 1680 U/ml in amniotic fluid of the first, second, and third trimesters, respectively. In maternal blood, 12.5% of pregnant women in the first trimester of pregnancy showed elevated levels of CA 125 (65 to 100 U/ml). Late in gestation, CA 125 levels in cord blood and fetal urine were always less than 65 U/ml. Immunohistochemical study of CA 125 in fetal membranes, placenta, and decidua showed the presence of antigen only in the amnion. These results suggest that CA 125 is shed into amniotic fluid directly from the amniotic membrane.

[Dyspeptic syndrome in heart diseases]

Many investigations have ascertained the relation between dyspepsia and diseases or disorders of gastrointestinal tract; on the contrary, the topics concerning the dyspeptic syndrome during acute cardiac disorders are very few. For this reason, Authors studied the upper tract of digestive apparatus in some patients affected with congestive heart failure and ischemic heart disease. Data have showed alterations of motility in esophagus, stomach and duodenum in every patient and lesions of gastric mucous membrane in more than half of them.

Comparison of faecal blood loss, upper gastrointestinal mucosal integrity and symptoms after piroxicam beta-cyclodextrin, piroxicam and placebo administration

In order to evaluate the gastric tolerance of the new piroxicam formulation CHF 1194 (piroxicam complexed with beta-cyclodextrin), a double-blind randomized trial was carried out in 21 young healthy volunteers comparing CHF 1194 with piroxicam and placebo. Faecal blood loss measurement by the Cr-51 labelled red blood cell technique, upper gastrointestinal endoscopic evaluation, titration of gastric pH and gastric biopsies before, during and after treatment were used to assess drug tolerability. Four out of 7 volunteers in the piroxicam-treated group withdrew because of severe gastrointestinal symptoms and oesophageal and/or gastroduodenal lesions, while all subjects treated with CHF 1194 or placebo completed the treatment. There was a significant difference between the endoscopic scores of the piroxicam and placebo groups, whereas no differences were found between CHF 1194 and placebo, nor between piroxicam and CHF 1194. Daily mean gastrointestinal blood loss was greater in the piroxicam group than in either the CHF 1194 or placebo groups, but the difference was not significant, due to the small number of piroxicam-treated subjects who completed the study. When administered for a short period to healthy young subjects, CHF 1194 caused less gastric damage and was better tolerated than piroxicam.

Heat shock, protein synthesis and ribosomal protein S6 phosphorylation in vitro in Yoshida AH 130 ascites hepatoma cells

An activated 40S ribosomal protein S6 kinase has been demonstrated previously in cytosolic extracts from proliferating as well as resting cells of a very undifferentiated rat ascites hepatoma cell line (Yoshida AH 130), grown in vivo (Cell Biol. Int. Rep., 1986, 10, 821-831). In the present report we present evidence of unmodified activity of this kinase and S6 phosphorylation in vitro in cells submitted to a physiological stress such as a sublethal temperature elevation (heat shock: 42 degrees C for 2 h). The heat treatment causes a progressive decline in the number of active ribosomes and of L-35S methionine incorporation into total protein, suggesting drastically decreased synthesis of cellular proteins under these conditions. Cells recovering from heat shock show the induced synthesis of a protein with an apparent Mr of 50 kDa. Spontaneous high expression of heat shock proteins (HSP 70, 89, 100), without heat shock, occurs in these tumor cells.

Activation of a ribosomal protein S6 kinase during the 4-dimethylaminoazobenzene-induced rat hepatocarcinogenesis

During the induction of 4-dimethylaminoazobenzene (DAB) hepatocarcinogenesis there was a progressive increase in the activity of a kinase which specifically phosphorylated S6 ribosomal protein in vitro. Liver tumour tissue (hepatocellular carcinoma and cholangioma) showed maximal activation of this kinase and elevated levels of S6 phosphorylation. Control rats fed with the same diet containing no dye showed a gradual decline of this activity, with low or lacking phosphorylation at the end of the experimental regimen, suggesting close correlation between tumor cell growth and phosphorylation of this ribosomal protein, under these conditions.

Protein synthesis, ribosomal protein S6 phosphorylation in vitro and the effects of amiloride: SDS gel electrophoresis studies in the Yoshida ascites tumor (AH 130) grown in vivo

Cell-free cytosolic extracts from the Yoshida (AH 130) rat ascites hepatoma cell line, grown in vivo, showed high ribosomal protein S6 kinase activity in vitro, as measured by transfer of 32P to exogenous 40S rat liver ribosomal subunits, in both exponential growing and stationary phase cells. A significant decrease of protein synthesis (3H-leucine incorporation into total cell protein) was found to occur in cells reaching the stationary phase of growth, suggesting that S6 phosphorylation was not tightly coupled to the rate of the intraperitoneal cell growth and of protein synthesis in these tumor cells. When the cell-free cytosolic extracts were prepared from cells exposed to amiloride, at concentrations that inhibit the Na+/H+ exchange, a decrease of S6 kinase activity was observed only in exponential growing cells, suggesting the possibility of coupling of the Na+/H+ exchange with phosphorylation of intracellular proteins in these tumor cells. Actually, stationary phase cells showed unchanged S6 kinase activity under the same conditions, possibly due to the extremely low Na+/H+ exchange activity, previously demonstrated (Cell Biol. Int. Rep., 1985, 9, 1017-1025). The present experiments support the hypothesis that the regulation of protein synthesis is not tightly coupled to phosphorylation-dephosphorylation cycles, at least of ribosomal protein S6, in cells characterized by a rather uncontrolled growth such as the Yoshida (AH 130) rat ascites hepatoma. In this connection, an elevated degree of protein phosphorylation, such as that of the ribosomal protein S6, could be a general phenomenon of neoplastic transformation.

Auditory evoked potentials in audiometric assessment of compensation and medicolegal patients

The clinical utility of auditory evoked potentials for validation of the pure tone audiogram in adult compensation claimants and medicolegal patients is examined. Large sample comparisons of evoked potential and conventional pure tone thresholds showed that the slow vertex response can estimate true hearing levels within 10 dB in almost all patients. Given adequate tester skills, it is the tool of choice, and it merits more widespread implementation. Properly used, it can improve and abbreviate the assessment battery for detection and quantification of nonorganic hearing loss. The 40-Hz middle latency response is useful as a secondary tool, but at present, cochlear nerve and brain stem potentials have limited audiometric value in this population.