Selective immediate responders to amoxicillin and clavulanic acid tolerate penicillin derivative administration after confirming the diagnosis.

BACKGROUND: An increasing number of patients show immediate selective hypersensitivity reactions to clavulanic acid (CLV) and amoxicillin (AX), probably due to their increased prescription. The maintenance of this response should be established. OBJECTIVE: To assess that the immediate hypersensitivity selective response to AX or to CLV is maintained after repeated administration of penicillin G (PG)/penicillin V (PV) and AX. METHODS: Patients with proven immediate hypersensitivity to AX (Group A) or CLV (Group B) were included. Diagnosis was performed using skin tests with major and minor determinants of PG (PPL/MDM), AX and CLV and by drug provocation test (DPT) if required. Selectivity was established by confirming tolerance to PG/PV (Group A) and to PG/PV and AX (Group B). The maintenance of the selective response was verified by repeating DPT, 15 days after the initial investigation, with the same procedure. RESULTS: Of 51 patients, 78% belonged to Group A and 22% to Group B. Most had anaphylaxis. In Group A, 72% were skin test positive; 28% required DPT. In Group B, 63% were skin test positive; 37% required DPT. Only two AX-selective cases developed positive responses after re-provocation with PG/PV. No cases selective for CLV developed a positive response to PG, PV or AX. DISCUSSION: The selective response to AX appears consistent, and a response to penicillin determinants only develops in a minority of cases. For the case of CLV, the selective response appears not to be modified by exposure to penicillin determinants, meaning that patients with CLV allergy can take penicillin derivatives safely.

Ultrasound-assisted extraction followed by disposable pipette purification for the determination of polychlorinated biphenyls in small-size biological tissue samples.

The use of solid-phase extraction pipette tip (also called disposable pipette extraction, DPX) has been evaluated for the purification of environmentally relevant polychlorinated biphenyls (PCBs) in fatty extracts obtained by ultrasound-assisted extraction with a sonication probe from small-size biological tissues. Complete sample treatment involved only 50 mg of sample and was completed in ca. 15 min with minimal sample manipulation and reagents consumption (i.e., 1.5 mL of n-hexane and 0.8 g of acidic silica). The performance of the proposed methodology for the intended determination was firstly evaluated by determination of the endogenous PCB levels in a naturally contaminated internal reference material. The determined concentrations showed a good agreement with those obtained using a more conventional sample preparation procedure previously validated in our laboratory (recoveries, as compared to levels determined using the latter method, were in the 85-123% range for a large majority of the studied congeners, and the relative standard deviations were in general lower than 14%). Results obtained for the analysis of reference food samples and certified reference materials NIST 1945 and 1947 demonstrated that, when combined with gas chromatography coupled to ion trap mass spectrometry working in the tandem mode, GC-ITD(MS/MS), the proposed methodology allowed accurate determination of most of the investigated PCBs and that 50 mg of sample sufficed for the screening of less abundant toxic congeners.

Deiodination in cancer growth: the role of type III deiodinase.

Thyroid hormone (TH) is a pleiotropic agent that has widespread biological functions, i.e., it controls cellular growth, tissue development and homeostasis and neoplastic transformation. Suitable TH levels are critical for the development of various types of tissues and are essential for the regulation of metabolic processes throughout life. The serum concentrations of TH affect its biological activity. Moreover, at tissue level, TH action is regulated by the expression and activity of deiodinases, i.e., the enzymes that mediate the metabolic pathways by activating and/or inactivating TH. The type I and II deiodinases (D1 and D2) initiate TH action by converting thyroxine (T4) into the active TH form (T3), whereas type III deiodinase (D3) mediates the local attenuation of TH by converting T4 and T3 into the inactive metabolites rT3 and T2, respectively. The deiodinase system is a potent mechanism of pre-receptoral control of TH action; it is often altered in such pathological conditions as cancer. D3 is widely expressed in embryonic tissues and in placenta, where it blocks excessive maternal-to-fetal transfer of TH. In contrast, during late neonatal and adult life, D3 is expressed mainly in the central nervous system and skin. Interestingly, D3 expression is re-activated in various types of human cancers. Here we review recent evidence that D3 expression plays a crucial role in human carcinogenesis, and speculate as to its complex role in the regulation of cell proliferation in several neoplastic contexts. It is conceivable that the local modulation of TH action via deiodinases is a powerful molecular tool to manipulate the intracellular TH status, thus influencing the growth and maintenance of selected hormone-dependent cancers.

[Adenocarcinoma of the appendix. A case report and review of the literature]. / L'adenocarcinoma dell'appendice ileo-ciecale: presentazione di un caso clinico e revisione della letteratura.

Primary adenocarcinoma of the appendix is a rare malignancy that constitutes less than 0.5% of all gastrointestinal neoplasms. Usually the diagnosis is made only after histological examination of surgically removed inflamed appendix. Alternatively represent an unexpected finding, confirmed by frozen section, during surgery performed for acute appendicitis or other non appendiceal pathologies. Natural history is strongly influenced by anatomic peculiarities of the appendix that predispose to early spread and perforation. Frequently is associated with synchronous and metachronous colorectal or extraintestinal cancers. The correct management is the right hemicolectomy as a primary procedure in the case of preoperatively or intraoperatively diagnosis or as secondary procedure, after two-three weeks from appendectomy, when the microscopic examination of specimen reveals the presence of adenocarcinoma. Right hemicolectomy is the best treatment for all histologic types (colonic, mucinous, adenocarcinoid), in presence of perforation and even in Dukes A tumors. A careful intraoperative search for synchronous lesions and a life-long program of surveillance for the detection of early stage metachronous carcinomas are recommended. The Authors report a case of primary adenocarcinoma of the appendix occurred in a 78 year-old female patient, diagnosed incidentally during surgery performed for ileus from suspected cecal neoplasm.

[Complicated diverticular disease. Three cases of colovesical fistulas and review of literature]. / La malattia diverticolare complicata: le fistole colo-vescicati. Presentazione di tre casi clinici e revisione della letteratura.

Colovesical fistulas represent a possible less frequent complication of diverticular disease of colon. They represent a complex condition because of the possible and unexpected evolution into a septic shock with a high risk of death. The Authors report three cases of colovesical fistula as a complication of diverticular disease. They underline the importance of early diagnosis, specific antibiotic therapy and appropriate surgical therapy realized in one or two stages according to general and local conditions of each patient.

A homology model of the pore region of HCN channels.

HCN channels are activated by membrane hyperpolarization and regulated by cyclic nucleotides, such as cyclic adenosine-mono-phosphate (cAMP). Here we present structural models of the pore region of these channels obtained by using homology modeling and validated against spatial constraints derived from electrophysiological experiments. For the construction of the models we make two major assumptions, justified by electrophysiological observations: i), in the closed state, the topology of the inner pore of HCN channels is similar to that of K(+) channels. In particular, the orientation of the S5 and S6 helices of HCN channels is very similar to that of the corresponding helices of the K(+) KcsA and K(+) KirBac1.1 channels. Thus, we use as templates the x-ray structure of these K(+) channels. ii), In the open state, the S6 helix is bent further than it is in the closed state, as suggested (but not proven) by experimental data. For this reason, the template of the open conformation is the x-ray structure of the MthK channel. The structural models of the closed state turn out to be consistent with all the available electrophysiological data. The model of the open state turned out to be consistent with all the available electrophysiological data in the filter region, including additional experimental data performed in this work. However, it required the introduction of an appropriate, experimentally derived constraint for the S6 helix. Our modeling provides a structural framework for understanding several functional properties of HCN channels: i), the cysteine ring at the inner mouth of the pore may act as a sensor of the intracellular oxidizing/reducing conditions; ii), the bending amplitude of the S6 helix upon gating appears to be significantly smaller than that found in MthK channels; iii), the reduced ionic selectivity of HCN channels, relative to that of K(+) channels, may be caused, at least in part, by the larger flexibility of the inner pore of HCN channels.

[A fecal fistula in patient who underwent an abdomino-perineal resection with a continent magnetic prosthesis: observations on an obsolete technique]. / Fistola stercoracea in paziente sottoposta ad intervento di Miles e portatrice di protesi magnetica: considerazioni su una tecnica obsoleta.

The Authors consider a case of a patient who underwent an abdominal-perineal resection and presented a fecal fistula as a late complication of a magnetic prosthesis implant. After a revision of the literature, the Authors evaluate the reasons for abandoning this surgical technique of continence many years ago, underlying not only the complications observed during the experimentation but also the lack of those benefits for which this technique was proposed.

[Pelvic abscesses. Treatment modalities and personal experience]. / Gli ascessi pelvici. Modalità di trattamento ed esperienza personale.

The pelvic abscesses as complication of surgical operations or various pathologies is a delicate clinical situation because of the possible and unexpected evolution into a settic shock with a high risk of death. The authors report their personal experience of 16 cases undergone surgical treatment. They underline the importance of an early diagnosis, of a control of the patient general conditions with a specific antibiotic therapy, of the possibility to treat this pathology in a percutaneous way with the help of radiologic techniques or eventually by surgery.

Adeno-associated viral vector-mediated human vascular endothelial growth factor gene transfer stimulates angiogenesis and wound healing in the genetically diabetic mouse.

AIMS/HYPOTHESIS: We studied the gene therapy efficacy of diabetes-associated wound healing disorder with an adeno-associated virus (AAV) vector expressing the 165-amino acid isoform of human vascular endothelial growth factor-A (VEGF-A) by using an incisional skin-wound model produced on the back of female diabetic C57BL/KsJ db+/db+ mice and their normal littermates ( db+/+m). METHODS: Animals were randomized to receive intradermally into the wound edges either rAAV-LacZ (a control gene), or rAAV-VEGF165. Animals were killed on different days (7 and 14 days after skin injury) and wounded skin tissues were used for gene marker studies, histological evaluation and immunohistochemistry, and wound breaking strength analysis. Furthermore we studied the VEGF mature protein in the wounds. RESULTS: We found that AAV vectors are highly efficient for gene transfer to the mouse skin, displaying an exquisite tropism for the panniculus carnosus by using the beta-galactosidase activity assay. We confirmed the increased expression of the angiogenic factor at day 7 by measuring the wound content of the mature protein. Delivery of VEGF165 to incisional skin wounds of diabetic mice resulted in a remarkable induction of new vessel formation with consequent improvement in the wound healing process. The rAAV-VEGF165 gene improved wound healing in diabetic mice through the stimulation of angiogenesis, reepithelization, synthesis and maturation of extracellular matrix. Moreover the recombinant AAV encoding the human VEGF165 increased the breaking strength of the wound and enhanced the wound content of VEGF. CONCLUSION/INTERPRETATION: Our study suggests that VEGF gene transfer might represent a new approach to treat wound healing disorders associated with diabetes.

Peritoneal mesothelioma in a case of inguinal hernia. A review of the literature.

The peritoneal mesothelioma (PM) is a rare, benign or malignant, primary tumour, arising from the peritoneal membrane. The most frequent histological form is the malignant one with an incidence of 2-2.6 new cases per million per year. The symptomatology is insidious and poses difficult problems in the diagnosis and the treatment. Instrumental diagnostic investigations are useful only in the diagnostic orientation. Only the pathologic examination allows to distinguish a peritoneal carcinomatosis from PM. The prognosis of MPM is pour. An intense multimodal therapy, combining surgery with CT and RT, increases the survival rates in the patients with MPM. It has been proposed that hernia of abdominal wall play a role in the pathogenesis of this tumor. We believe that hypothesis seems unlikely considering the enormous discrepancy between the incidence of hernial pathology and PM.

NMDA-evoked excitotoxicity increases tissue transglutaminase in cerebellar granule cells.

In neuronal cells, excessive activation of glutamate receptors causes excitotoxic damage culminating in apoptotic and necrotic cell death. The molecular mechanism of excitotoxicity has been associated with excessive Ca(2+) influx and overload, triggering biochemical events that lead to cell death and tissue degeneration. Following mild insults via NMDA-receptor activation, central neurons undergo several biochemical modifications recognizable as early events in apoptotic machinery.Tissue transglutaminase, the most ubiquitous among cell transglutaminases, catalyzes the Ca(2+)-dependent protein cross-linking probably associated with morphological changes in several neurodegenerative disorders. The possible involvement of this enzyme in excitotoxicity-mediated events was investigated in primary cultures of cerebellar granule cells exposed for 30 min to NMDA (100 microM) in Locke's buffer. Under these conditions time-dependent increases in transglutaminase activity were observed. Tissue transglutaminase expression reached the highest levels within 3-4 h of NMDA exposure. Similarly, high levels of incorporation of fluorescent substrates were observed in living cells. Confocal laser microscopy analysis showed that fluorescein-labelled structures were distributed within the cytoplasm and close to the membranes of NMDA-exposed cells. These effects were dependent on the Ca(2+) influx triggered by the excitotoxic stimulus. Morphological changes in NMDA-treated cells gave evidence of significant cell damage which appeared within 5-6 h of NMDA exposure. These results suggest that increases in tissue transglutaminase may be associated to the effects of NMDA-induced excitotoxicity. Therefore, it is reasonable to hypothesize that if tissue transglutaminase levels and activity are up-regulated under such conditions, the protein cross-linking could be likely involved in excitotoxic response.

Recombinant AAV vector encoding human VEGF165 enhances wound healing.

Delivery of therapeutic genes represents an appealing possibility to accelerate healing of wounds that are otherwise difficult to treat, such as those in patients with metabolic disorders or infections. Experimental evidence indicates that in such conditions potentiation of neo-angiogenesis at the wound site might represent an important therapeutic target. Here we explore the efficacy of gene therapy of wound healing with an adeno-associated virus (AAV) vector expressing the 165 amino acid isoform of vascular endothelial growth factor-A (VEGF-A). By gene marker studies, we found that AAV vectors are highly efficient for gene transfer to the rat skin, displaying an exquisite tropism for the panniculus carnosus. Gene expression from these vectors is sustained and persistent over time. Delivery of VEGF165 to full thickness excisional wounds in rats resulted in remarkable induction of new vessel formation, with consequent reduction of the healing time. Histological examination of treated wounds revealed accelerated remodeling of epidermis and dermis, with formation of a thick granular layer, containing numerous newly formed capillaries, as well as vessels of larger size. These data underline the importance of neo-angiogenesis in the healing process and indicate that VEGF gene transfer might represent a novel approach to treat wound healing disorders.

Eruptive syringomas with calcium deposits in a young woman with Down's syndrome.

Eruptive syringomas are uncommon in the general population. We describe here an 18-year-old female, affected by Down's syndrome, who presented with an abrupt eruption of small skin-colored or reddish papules on the face, neck and limbs. Light microscopy allowed us to diagnose syringomas, whereas the study of the ultrastructural features revealed calcium deposits in many lumina and also in the mitochondria. This observation confirms the hypothesis that the syringeal structure plays a role in the pathogenesis of calcinosis cutis.

Distributed motor pattern underlying whole-body shortening in the medicinal leech.

Whole-body shortening was studied in the leech, Hirudo medicinalis, by a combination of videomicroscopy and multielectrode recordings. Video microscopy was used to monitor the animal behavior and muscle contraction. Eight suction pipettes were used to obtain simultaneous electrical recordings from fine roots emerging from ganglia. This vital escape reaction was rather reproducible. The coefficient of variation of the animal contraction during whole-body shortening was between 0.2 and 0.3. The great majority of all leech longitudinal motoneurons were activated during this escape reaction, in particular motoneurons 3, 4, 5, 8, 107, 108, and L. The firing pattern of all these motoneurons was poorly reproducible from trial to trial, and the coefficient of variation of their firing varied between 0.3 and 1.5 for different motoneurons. The electrical activity of pairs of coactivated motoneurons did not show any sign of correlation over a time window of 100 ms. Only the left and right motoneurons L in the same ganglion had a correlated firing pattern, resulting from their strong electrical coupling. As a consequence of the low correlation between coactivated motoneurons, the global electrical activity during whole-body shortening became reproducible with a coefficient of variation below 0.3 during maximal contraction. These results indicate that whole-body shortening is mediated by the coactivation of a large fraction of all leech motoneurons, i.e., it is a distributed process, and that coactivated motoneurons exhibit a significant statistical independence. Probably due to this statistical independence this vital escape reaction is smooth and reproducible.

Apoptosis and necrosis occurring in excitotoxic cell death in isolated chick embryo retina.

Excitotoxic studies using isolated chick embryo retina indicated that such an in vitro model provides a valid tool to characterize the effect of different agonists for subtypes of glutamate ionotropic receptors. In retinas maintained for 24 h in a Krebs medium, after a brief exposure (30 min) to glutamate agonists, we compared the effects produced by NMDA and non-NMDA-agonists, such as kainic acid (KA) or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Delayed retinal damage was assessed by measuring lactate dehydrogenase (LDH) present in the medium after exposure to the previously named agonists. Although at high concentrations, both KA and AMPA produced more relevant release than NMDA, 7-8% of total retinal LDH was released after exposure to a 50 microM concentration of non-NMDA agonists. These values were similar to those obtained after 100 microM NMDA. In this regard, retinal tissue appeared to be less sensitive to excitotoxicity based on the activation of NMDA receptor subtype. All three agents produced histopathological lesions typical for excitotoxic damage. A delayed form of excitotoxicity observed in retina segments was predominated by necrotic features. However, the activation of apoptotic machinery early during the incubation period subsequent to brief exposure to NMDA (100 microM) was also present. The activation of caspase enzymes was studied by a fluorometric protease activity assay as well as by western blot analysis. Caspase-3-like activity reached the highest value within 3 h of incubation after exposure to excitotoxin, then the level of enzyme activity declined to lower values. As confirmed by a time-related appearance of TUNEL-positive nuclei, apoptotic features appeared to be specific for retina response to NMDA. In contrast, the exposure to a 50 microM concentration of KA or AMPA induced necrotic cell damage which was evident through the incubation, leading to a delayed mechanism of excitotoxicity. These observations provide evidence that in the retinal model, with regard to agonist concentrations and subtype of glutamate receptors, the cascade of events leading to excitotoxicity may result in either apoptotic or necrotic neuronal cell damage.

The use of optical flow to characterize muscle contraction.

Muscle contraction is usually measured and characterized with force and displacement transducers. The contraction of muscle fibers, however, evokes in the tissue a two and even three-dimensional displacement field, which is not properly quantified by these transducers because they provide just a single scalar quantity. This problem can be circumvented by using optical measurements and standard tools of computer vision, developed for the analysis of time varying image sequences. By computing the so called optical flow, i.e. the apparent motion of points in a time varying image sequence, it is possible to recover a two-dimensional motion field, describing rather precisely the displacement caused by muscle contraction in a flattened piece of skin. The obtained two-dimensional optical flow can be further analyzed by computing its elementary deformation components, providing a novel and accurate characterization of the contraction induced by different motoneurons. This technique is demonstrated analyzing the displacement caused by muscle contraction in the skin of the leech, Hirudo medicinalis. The proposed technique can be applied to monitor and characterize all contractions in almost flat tissues with enough visual texture.

Mechanisms involved in stimulation of human immunodeficiency virus type 1 replication by aminooxypentane RANTES.

Aminooxypentane (AOP)-RANTES is a potent inhibitor of nonsyncytium-inducing (NSI), CCR5-tropic (R5) human immunodeficiency virus type 1 (HIV-1) isolates. Although classical chemotactic responses are not induced in primary leukocytes by AOP-RANTES, recent studies suggest that a remnant of cell signaling occurs upon binding of receptor to this compound. We have detected a breakthrough of NSI/R5 replication from the inhibitory effects of high AOP-RANTES concentrations (<100 nM). A stimulation of different primary syncytium-inducing (SI), CXCR4-tropic (X4) HIV-1 isolates was also observed in the presence of AOP-RANTES. This stimulation was also observed after 110 h in PCR and RT-PCR for minus-strand strong-stop DNA and unspliced and multiply spliced RNA, respectively. However, there was significant variability between different SI/X4 or NSI/R5 HIV-1 isolates with regard to this AOP-RANTES-mediated stimulation or breakthrough, respectively. To further define the mechanism(s) responsible for this AOP-RANTES effect, we performed detailed retroviral replication studies with an NSI/R5 (B-92BR021) and SI/X4 (D-92UG021) HIV-1 isolate in the presence of the drug. Treatment of peripheral blood mononuclear cells with 125 nM AOP-RANTES and virus did not alter coreceptor expression, HIV-1 entry, reverse transcription, or mRNA transcription from the long terminal repeat, but it did result in increased HIV-1 integration. This AOP-RANTES-mediated increase in HIV-1 integration was diminished by treatment with pertussis toxin. Phosphorylation of the mitogen-activated protein kinase (MAPK) isoforms, extracellular signal-regulated kinase 1 (ERK1) and ERK2, was increased in a CD4(+) CCR5(+) U87 cell line treated with AOP-RANTES or with an NSI/R5 HIV-1 isolate. These findings suggest that AOP-RANTES may induce a MAPK/ERK signal transduction pathway upon binding to a G-protein-coupled receptor. MAPK/ERK1 and -2 appear to phosphorylate the HIV-1 preintegration complex, a step necessary for nuclear translocation and successful integration.

[Endoscopic treatment of non-neoplastic cholestasis]. / L'approccio endoscopico alla colestasi ad etiopatogenesi non neoplastica.

Now, draining the cholestasis by endoscopic way is a safe and effective solution. The most of Authors think that the non neoplastic cholestasis find her substantial solution by endoscopic methodology. We reported the most important endoscopic techniques used in these cases, especially the papillosphincterotomy, the pneumatic dilatation and the placing of endoprosthesis.