Rectal intussusception: can high resolution three-dimensional ano-rectal manometry compete with conventional defecography?

BACKGROUND: Three-dimensional high-resolution anorectal manometry (3DHRAM), used for exploring anorectal disorders, was recently developed, providing interesting topographic data for the diagnosis of pelvic floor disorders such as excessive perineal descent. The aim of our study was to define a diagnostic strategy based on selected 3DHRAM parameters to identify rectal intussusceptions (RI), considering conventional defecography (CD) as the gold standard. METHODS: All patients referred to our center in the previous 6 months for 3DHRAM to explore fecal incontinence or constipation, and who previously achieved CD, were eligible. 3DHRAM results were obtained for all classical parameters and the presence of a narrow band of high pressure in the anal canal during attempted defecation, which was recently found to be associated with RI in some studies. The sensitivity, specificity, and positive and negative predictive values were calculated for various 3DHRAM criterion in order to propose a diagnostic strategy for RI. KEY RESULTS: Twenty-six patients (66%) presented with RI on CD. On 3DHRAM, according to our diagnostic strategy, the most relevant manometric criterion for the diagnosis of RI was the association of an anterior additional high-pressure area and an excessive perineal descent, with a positive predictive value of 100% [81.5-100], a specificity of 100% [75.3-100] and a sensibility of 69.2% [48.2-85.7]. CONCLUSIONS & INFERENCES: In this study, 3DHRAM was used to diagnose RI, and we confirmed its use in the diagnosis of pelvic floor disorders. Further studies will be necessary to define classifications for these new anatomic data from 3DHRAM.

[Pseudotumoral pulmonary AL amyloidosis]. / Amylose AL pulmonaire de forme pseudo-tumorale.

INTRODUCTION: Thoracic involvement in amyloidosis is rare. An isolated pseudotumor without extra-thoracic disease suggests a malignant process. We present the case of a patient with pseudonodular AL amyloidosis, confirmed by lobar lung resection. CASE REPORT: A 57-year-old woman, with a 25-pack-year smoking history, presented with a nodular opacity on chest x-ray. Physical examination was normal. Thoracic CT-scan revealed an isolated spiculated nodule in the right upper lobe. A whole body positron emission tomography (PET) scan revealed high FDG activity in this nodule, without evidence of metastatic disease. Bronchoscopy was negative. Lobectomy revealed lambda L-chain amyloidosis. Investigation for systemic extension was negative. Follow up has been unremarkable. CONCLUSION: A spiculated lung nodule on conventional imaging (radiography, scanner) is cancer until proven otherwise. The use of PET scan in this context is sensitive but not specific. Definitive diagnosis must be obtained by histological examination. Nodular lung amyloidosis must be included in the differential diagnosis of lung nodules and false-positive FDG PET.

Buccodental side effects of sunitinib in patients with metastatic renal cell carcinoma.

BACKGROUND: Sunitinib is a tyrosine kinase inhibitor approved for the treatment of renal cell carcinoma (RCC). Few data evaluated severe buccodental adverse events. The aim of this study was to evaluate sunitinib buccodental toxicity in patients with metastatic RCC and to compare it with that of standard chemotherapy in patients with other solid cancers. METHODS: Patients with RCC treated with sunitinib and patients with other solid tumours treated with chemotherapy were followed for 3 months. Data on dental appliances, oral hygiene/care practices before and during treatment were collected. RESULTS: A total of 116 patients were included (58 RCC treated by sunitinib: group S, and 58 treated by chemotherapy: group C). No differences in dental care habits were noted before treatment. In group S, patients reported significantly more frequent pain (P<0.01), teeth instability (P=0.01), gingival bleeding (P=0.01) and change in teeth colour (P=0.02). In all, 58% of patients in this group had to modify their diet (P<0.01). Frequency of dentist visits for teeth removal was increased (25% vs 8%, P=0.01). CONCLUSION: Sunitinib seems to increase buccodental toxicity as compared with chemotherapy. This finding emphasises the need for optimal dental care and standardised dental follow-up in patients treated with sunitinib.

Postnatal Growth Patterns in a Chilean Cohort: The Role of SES and Family Environment.

Objective. This study examined how family environmental characteristics served as mediators in the relationship between socioeconomic conditions and infant growth in a cohort of Chilean infants. Methods. We studied 999 infants, born between 1991 and 1996, from a longitudinal cohort which began as an iron deficiency anemia preventive trial. SES (Graffar Index), the Life Experiences Survey, and the Home Observation for Measurement of the Environment (HOME) were assessed in infancy. Using path analysis, we assessed the relationships between the social factors, home environment, and infant growth. Results. During the first year, weight and length gain averaged 540 grams/month and 6.5 cm/month, respectively. In the path analysis model for weight gain, higher SES and a better physical environment were positively related to higher maternal warmth, which in turn was associated with higher average weight gain. Higher SES was directly related to higher average length gain. Conclusions. In our cohort, a direct relationship between SES and length gain developed during infancy. Higher SES was indirectly related to infant weight gain through the home environment and maternal warmth. As the fastest growing infants are at risk for later obesity, new strategies are needed to encourage optimal rather than maximal growth.

From a dull enzyme to something else: facts and perspectives regarding aldose reductase.

Aldose Reductase (ALR2) is defined as the first enzyme of the "polyol pathway". As such, ALR2 would convert glucose to sorbitol through an NADPH dependent reaction. Considered a promoter of osmotic imbalance under hyperglycemic conditions, the enzyme has been under intense investigation as a critical target to prevent and control diabetic complications through the inhibition of its activity. Further characterization of ALR2 suggests its participation in cell detoxification mechanisms through the reduction of toxic aldehydes. Moreover, intriguing is the apparent involvement of the enzyme in the signalling machinery of inflammatory cell response. Here, the structural and functional assessment of ALR2 as an aldose/aldehyde reducing enzyme, and its involvement in various aspects of cell function from sugar metabolism to redox homeostasis and cell signaling are presented.

Thiol/disulfide interconversion in bovine lens aldose reductase induced by intermediates of glutathione turnover.

The effectiveness of cysteine and cysteinylglycine to act as protein thiolating agents was investigated using bovine lens aldose reductase (ALR2) as the protein target. Disulfides of both thiol compounds appear to be very effective as ALR2 thiolating agents. Cysteine- and CysGly-modified ALR2 forms (Cys-ALR2 and CysGly-ALR2, respectively) are characterized by the presence of a mixed disulfide bond involving Cys298, as demonstrated by a combined electrospray mass spectrometry and Edman degradation approach. Both Cys-ALR2 and CysGly-ALR2 essentially retain the ability to reduce glyceraldehyde but lose the susceptibility to inhibition by Sorbinil and other ALR2 inhibitors. Cys-ALR2 and CysGly-ALR2 are easily reduced back to the native enzyme form by dithiothreitol and GSH treatment; on the contrary, Cys and 2-mercaptoethanol appear to act as protein trans-thiolating agents, rather than reducing agents. The treatment at 37 degrees C of both Cys-ALR2 and CysGly-ALR2, unlikely what observed for glutathionyl-modified ALR2 (GS-ALR2), promotes the generation of an intramolecular disulfide bond between Cys298 and Cys303 residues. A rationale for the special susceptibility of Cys-ALR2 and CysGly-ALR2, as compared to GS-ALR2, to the thermally induced intramolecular rearrangement is given on the basis of a molecular dynamic and energy minimization approach. A pathway of thiol/disulfide interconversion for bovine lens ALR2 induced, in oxidative conditions, by physiological thiol compounds is proposed.

Modulation of aldose reductase activity through S-thiolation by physiological thiols.

The glutathionyl-modified aldose reductase (GS-ALR2) is unique, among different S-thiolated enzyme forms, in that it displays a lower specific activity than the native enzyme (ALR2). Specific interactions of the bound glutathionyl moiety (GS) with the ALR2 active site, were predicted by a low perturbative molecular modelling approach. The outcoming GS allocation, involving interactions with residues relevant for catalysis and substrate allocation, explains the rationale behind the observed differences in the activity between GS-ALR2 and other thiol-modified enzyme forms. The reversible S-glutathionylation of ALR2 observed in cultured intact bovine lens undergoing an oxidative/non oxidative treatment cycle is discussed in terms of the potential of ALR2/GS-ALR2 inter-conversion as a response to oxidative stress conditions.

Suppression of Il-12 transcription in macrophages following Fc gamma receptor ligation.

Ligating Fc gamma R on macrophages results in suppression of IL-12 production. We show that Fc gamma R ligation selectively down-regulates IL-12 p40 and p35 gene expression at the level of transcription. The region responsive to this inhibition maps to the Ets site of the p40 promoter. PU.1, IFN consensus sequence binding protein, and c-REL: form a complex on this element upon macrophage activation. Receptor ligation abolishes the binding of this PU.1-containing activation complex, and abrogates p40 transcription. A dominant-negative construct of PU.1 diminishes IL-12 p40 promoter activity and endogenous IL-12 p40 protein secretion. Thus, the specificity of IL-12 down-regulation following receptor ligation lies in the inhibition of binding of a PU.1-containing complex to the Ets site of the IL-12 promoter. These findings provide evidence demonstrating for the first time the importance of PU.1 in the transcriptional regulation of IL-12 gene expression.

NAAG inhibits KCl-induced [(3)H]-GABA release via mGluR3, cAMP, PKA and L-type calcium conductance.

The peptide neurotransmitter, N-acetylaspartylglutamate (NAAG), is a selective agonist at the type 3 metabotropic glutamate receptor (mGluR3) where it acts to decrease cAMP levels. Rat cortical interneurons express both NAAG and glutamic acid decarboxylase, as well as mGluR3 mRNA. In the presence of ionotropic glutamate receptor antagonists, both NAAG and the group II metabotropic glutamate receptor agonist, DCG-IV, reduced the calcium-dependent, KCl-induced [(3)H]-GABA release from rat cortical neurons by 35%. This release process was unaffected by tetrodotoxin. The group II antagonist, ethyl glutamate, reversed the effects of DCG-IV and NAAG. The mGluR3-selective antagonist, beta-N-acetylaspartylglutamate, reversed the effect of NAAG. While pretreatment of cortical neurons with forskolin alone did not significantly affect KCl-stimulated [(3)H]-GABA-release, forskolin abolished the inhibition of release produced by NAAG. The protein kinase A inhibitor, H-89, decreased [(3)H]-GABA release while NAAG produced no additional inhibition in the presence of H-89. In contrast, the protein kinase C inhibitor, Ro 31--8220, had no effect on KCl-stimulated release, nor did it affect the inhibition of release produced by NAAG. The L-type calcium channel blocker, nifedipine, also inhibited the release of [(3)H]-GABA and coapplication with NAAG resulted in no significant additional inhibition of release. These data support the hypothesis that the inhibition of KCl-stimulated [(3)H]-GABA release by NAAG is mediated via presynaptic mGluR3 on GABAergic cortical neurons and that this effect is obtained by decreasing cAMP with a consequent decrease in protein kinase A activity and L-type calcium channel conductance.

Thiol disulfide exchange modulates the activity of aldose reductase in intact bovine lens as a response to oxidative stress.

The reversibility of S-thiolation of aldose reductase was shown in intact bovine lens subjected to oxidative stress. The glutathione modified aldose reductase generated in the lens as a consequence of hyperbaric oxygen treatment was recovered in its reduced form following culturing in normobaric air conditions. Nucleus and cortex were differently affected by both oxidative treatment and normobaric air recovery. The extent of S-thiolation of aldose reductase appeared to be higher in the nucleus than in the cortex. Moreover, the nucleus, but not the cortex, was unable to completely recover from the protein S-thiolation process. The ratios of GSH/GSSG and NADPH/NADP(+)as well as the Energy Charge values were determined in the cortex and nucleus both after oxidative stress and recovery. The results are consistent with the existence of a quite well-defined boundary between the two lens regions. Moreover, they are supportive of the hypothesis that thiol/disulfide exchange has the potential to be a regulatory mechanism for certain enzymes which can modulate the flux of NADPH inside the cell.

In vitro recycling of alpha-D-ribose 1-phosphate for the salvage of purine bases.

In this paper, we extend our previous observation on the mobilization of the ribose moiety from a purine nucleoside to a pyrimidine base, with subsequent pyrimidine nucleotides formation (Cappiello et al., Biochim. Biophys. Acta 1425 (1998) 273-281). The data show that, at least in vitro, also the reverse process is possible. In rat brain extracts, the activated ribose, stemming from uridine as ribose 1-phosphate, can be used to salvage adenine and hypoxanthine to their respective nucleotides. Since the salvage of purine bases is a 5-phosphoribosyl 1-pyrophosphate-dependent process, catalyzed by adenine phosphoribosyltransferase and hypoxanthine guanine phosphoribosyltransferase, our results imply that Rib-1P must be transformed into 5-phosphoribosyl 1-pyrophosphate, via the successive action of phosphopentomutase and 5-phosphoribosyl 1-pyrophosphate synthetase; and,in fact, no adenosine could be found as an intermediate when rat brain extracts were incubated with adenine, Rib-1P and ATP, showing that adenine salvage does not imply adenine ribosylation, followed by adenosine phosphorylation. Taken together with our previous results on the Rib-1P-dependent salvage of pyrimidine nucleotides, our results give a clear picture of the in vitro Rib-1P recycling, for both purine and pyrimidine salvage.

Uridine 5'-diphosphoglucuronic acid (UDPGLcUA) in the human fetal liver, kidney and placenta.

The endogenous concentration of uridine 5'-diphosphoglucoronic acid (UDPGLcUA), the endogenus substrate of UDP-glucuronosyltransferase, was measured in the human fetal and adult liver and kidney and in the placenta. The concentrations (mumol/Kg wet weight) of UDPGLcUA were 59.4 +/- 11.3 (fetal liver), 301 +/- 119 (adult liver), 11.9 +/- 3.2 (fetal kidney), 17.4 +/- 3.0 (adult kidney), 17.8 +/- 1.8 (mid-term placenta) and 17.0 +/- 1.7 (term placenta). UDPGLcUA is present in the human fetal liver at a concentration 5-fold lower than in the adult liver indicating a potential limiting factor for glucuronidation ind the human fetus.

Ribose 1-phosphate and inosine activate uracil salvage in rat brain.

The purpose of this study was to determine the mechanism by which inosine activates pyrimidine salvage in CNS. The levels of cerebral inosine, hypoxanthine, uridine, uracil, ribose 1-phosphate and inorganic phosphate were determined, to evaluate the Gibbs free energy changes (deltaG) of the reactions catalyzed by purine nucleoside phosphorylase and uridine phosphorylase, respectively. A deltaG value of 0.59 kcal/mol for the combined reaction inosine+uracil <==> uridine+hypoxanthine was obtained, suggesting that at least in anoxic brain the system may readily respond to metabolite fluctuations. If purine nucleoside phosphorolysis and uridine phosphorolysis are coupled to uridine phosphorylation, catalyzed by uridine kinase, whose activity is relatively high in brain, the three enzyme activities will constitute a pyrimidine salvage pathway in which ribose 1-phosphate plays a pivotal role. CTP, presumably the last product of the pathway, and, to a lesser extent, UTP, exert inhibition on rat brain uridine nucleotides salvage synthesis, most likely at the level of the kinase reaction. On the contrary ATP and GTP are specific phosphate donors.

A new approach against sugar cataract through aldose reductase inhibitors.

Aldose reductase inhibition is one of the therapeutic strategies that has been proposed to prevent or ameliorate long term diabetic complications including retinopathy and sugar cataract. Rats were fed with a galactose rich diet and the aldose reductase inhibitor Tolrestat was topically delivered by ocular instillation. The levels of lens aldose reductase activity, galactitol and the onset of cataract were evaluated during and after treatment with the inhibitor. Topical application of 1-3% Tolrestat (10 microl) four times daily resulted, after 9 days, in a significant decrease in the enzyme activity. Well after interrupting treatment with the drug, the enzyme activity remained impaired and galactose induced cataract was prevented. Our findings may represent the basis for therapeutic plans to prevent sugar cataract by long term cyclic treatments with aldose reductase inhibitors, with reduction in drug doses and side effects.

Physical and genetic map of Streptococcus mutans GS-5 and localization of five rRNA operons.

The physical map of the 2.1 megabase chromosome of Streptococcus mutans GS-5 has been refined by including all ApaI and SmaI fragments of 5 kbp or greater, and by positioning the fragments generated by the endonuclease I-CeuI. Sixty-three new genetic loci have been added to the map, so that it now contains 90 loci. The new loci include those for 35 cloned streptococcal genes of established function and for 23 S. mutans genes of putative function. In addition, five rrn operons were identified and placed on the map of the chromosome. The presence of a SmaI site in each of the rrn operons allowed the direction of transcription of each operon to be deduced. The orientation of the rrn loci indicates that their transcription is directed away from a small region of the chromosome, identifying a possible region for the initiation of chromosome replication.

In vitro assessment of salvage pathways for pyrimidine bases in rat liver and brain.

In this paper we extend our previous observation on the mobilization of the ribose moiety from guanosine to xanthine catalyzed by rat liver extracts (Giorgelli et al., Biochim. Biophys. Acta 1335 (1997) 16-22). The data show that in rat liver and brain extracts the activated ribose, stemming from inosine and guanosine phosphorolysis as ribose 1-phosphate, can be used to salvage uracil to uracil nucleotides. Uridine is an intermediate. The salvage process occurs even in the presence of excess inorganic phosphate suggesting that uridine phosphorylase may function in vivo as an anabolic enzyme. Ribose 5-phosphate cannot substitute for inosine, guanosine or ribose 1-phosphate as ribose donor. When inorganic phosphate was substituted with arsenate, hindering the formation of ribose 1-phosphate, no ribose transfer could be observed. A similar pathway occurs at the deoxy level. The deoxyribose moiety of deoxyinosine can be used to salvage thymine to thymine nucleotides, again in the presence of excess inorganic phosphate. Our results introduce a novel aspect of the salvage pathway, in which ribose 1-phosphate seems to play a pivotal role.

Molecular epidemiology by ribotyping and PCR-ribotyping of Enterococcus faecium strains isolated from intercontinental areas.

In this study classical ribotyping based on hybridization of an enteroccocal ribosomal operon previously cloned from Enterococcus hirae (Sechi and Daneo-Moore, 1993) with XbaI cut chromosomal DNA and PCR-ribotyping were used to characterize the molecular epidemiology of 131 Enterococcus faecium, with high-level resistance to gentamicin, isolated from different hospitals in Italy and the United States. The ribotyping was able to differentiate all 131 clinical isolates into 96 family patterns. These family patterns appeared to be useful in establishing epidemiological spread. The results obtained were in agreement with those previously published, suggesting the presence of five to six operons in the Enterococcus genus (Sechi et al., 1994). We performed PCR-ribotyping, based on conserved sequences at the 3' end of the enterococcal 16S rrn and the 5' end of the 23S rrn, on 131 clinical isolates as well as on several enterococcal ATCC strains tested. The results were then compared with those obtained with the classical ribotyping method. The results suggest the presence of at least four classes of intergenic spacers among enterococci, but these classes are not helpful in differentiating between Enterococci or among Enterococcal isolates.