Diagnostic accuracy of contrast-enhanced magnetic resonance angiography and duplex ultrasound in patients with peripheral vascular disease

INTRODUCTION

Noninvasive techniques such as duplex ultrasound (DU) and contrast-enhanced magnetic resonance angiography (CE-MRA) are valid alternatives in the preoperative evaluation of such patients. Our aim is to assess the diagnostic accuracy of CE-MRA and DU in patients with peripheral arterial disease (PAD).

METHODS

Forty consecutive patients underwent DU, hybrid CE-MRA, and digital subtraction angiography (DSA). Magnetic resonance angiography and DSA images were evaluated independently and in a blinded fashion. Every segment was graded as normal, stenosed less than 50%, stenosed more than 50%, or occluded.

RESULTS

There were 1720 segments for analysis. Duplex ultrasound depicting stenosis >50% demonstrated a sensitivity (S) 81.4%, specificity (E) 99%, positive predictive value (PPV) 96.2%, and negative predictive value (NPV) 94.8%. Occlusions showed S 90%, E 97%, PPV 98.1%, and NPV 88.4%. Magnetic resonance angiography depicting stenosis >50% demonstrated a S 91%, E 99%, PPV 96.7%, and NPV 97.6%. Occlusions showed S 95.4%, E 98%, PPV 98.4%, and NPV 94.7%.

CONCLUSION

Combined CE-MRA and DU is the first diagnostic approach in the preoperative assessment of PAD, leading to the use of DSA for selected cases.

Evaluation of the potential association of preoperative chemotherapy with steatohepatitis in surgical patients with hepatic colorectal metastases

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Background: The treatment of hepatic colorectal cancer metastases is increasingly multi-modal. Preoperative chemotherapy may be associated with steatohepatitis, which may increase morbidity in patients undergoing resection. Our objective was to determine if preoperative chemotherapy is associated with steatohepatitis and to determine which agents confer the greatest risk. Materials and Methods: 149 patients who had undergone liver resection or biopsy for hepatic colorectal cancer metastases were identified from an institutional database. Surgical specimens were assessed for percent steatosis and the presence of steatohepatitis as defined by the Kleiner score. The medical record was reviewed for details of preoperative chemotherapy and post-operative course. The association of preoperative chemotherapy with steatosis and steatohepatitis was assessed. Preoperative non-contrast CT scans were reviewed for evidence of steatosis as determined by the radiographic liver/spleen (L/S) ratio. The association of the L/S ratio with the presence of steatohepatitis was determined. Post-operative outcome was compared in patients with and without steatohepatitis. Results: The mean age of the population was 60.8 ±11.6 years, 56% of patients were male, and 37% of patients received preoperative chemotherapy. Steatohepatitis was identified in 45.7% of specimens. There was no statistically significant difference in the rate of steatohepatitis (59% vs. 50%, p=0.49) or percent steatosis (37% vs. 32%, p=0.29) with or without preoperative chemotherapy. No individual agent predicted a greater risk of steatohepatitis or a greater degree of steatosis. There was no significant difference in the L/S ratio in patients with or without steatohepatitis (p=NS). In patients undergoing liver resection, there was no difference in total ICU stay, blood loss, total surgery time or total length of stay between the steatohepatitis and non-steatohepatitis groups. Conclusions: Although steatohepatitis remains a potential complication of systemic chemotherapy in surgical patients with hepatic colorectal metastases, the risk and impact of chemotherapy associated steatohepatitis have not been significant in our patient population.

No significant financial relationships to disclose.

Impact of model for end-stage liver disease on patient survival and disease-free survival in patients receiving liver transplantation for hepatocellular carcinoma

We combined data from two transplant centers to determine the impact of the model for end-stage liver disease (MELD) allocation system on outcomes in patients undergoing liver transplantation for hepatocellular carcinoma (HCC). We compared 55 patients listed before MELD to 117 patients in the MELD era. Patients before MELD were less likely to receive a transplant (67% vs 91%) and waited a median of 127 days vs 20 days (P < .001). On an intention to treat (ITT) basis, the 1-, 3-, and 5-year survivals for patients before MELD were 79%, 60%, and 48%, and in the MELD era were 84%, 73%, and 73% (P = .055). On an ITT basis, the 1-, 3-, and 5-year tumor-free survivals before MELD were 58%, 58%, and 55% vs 83%, 74%, and 70% in the MELD era (P = .018). In patients who received a transplant, however, there were no differences in overall or tumor-free survival. In these patients, the 1-, 3-, and 5-year patient survivals were 92%, 84%, and 67% before MELD, and 90%, 81%, and 81% in the MELD era (P = .57). In transplanted patients, the 1-, 3-, and 5-year tumor-free survivals before MELD were 88%, 88%, and 83% vs 92%, 83%, and 78% in the MELD era (P = .403). On explant, patients listed before MELD had lower grade tumors (P = .046). We concluded that patients with HCC listed in the MELD era had higher and more rapid rates of transplantation with improvements in survival. However, the more efficacious rates of transplantation did not result in lower rates of tumor recurrence.

Incidental hepatocellular carcinoma after liver transplantation: population characteristics and outcomes

We combined data from two liver transplant centers to determine the tumor characteristics and outcomes of 51 patients transplanted with incidental hepatocellular carcinoma (iHCC) compared with 143 patients transplanted for previously known HCC (pkHCC). There were no differences in age, gender, or frequency of hepatitis C infection. Patients with iHCC were more likely to be African-American (22% vs 10%; P = .016), more likely to be screened by ultrasound (38% vs 9%; P < .001), had a lower alpha-fetoprotein (83.9 +/- 258.1 vs 572.4 +/- 2376.4 ng/mL; P = .005), and had a higher model for end-stage liver disease (MELD) score (14.3 +/- 4.1 vs 11.8 +/- 4.7; P < .001). The liver explants of patients with iHCC had smaller total tumor burden than patients with pkHCC (3.1 +/- 3.5 vs 4.1 +/- 2.6 cm; P < .001), but a similar percentage of single lesions (66% vs 65%) and tumors that met Milan criteria (76% vs 65%). Patients with iHCC had 1-, 3-, and 5-year survivals of 78%, 67%, and 58%, and 1-, 3-, and 5-year recurrence-free survivals of 90%, 87%, and 87% compared with the 1-, 3-, and 5-year survivals of 90%, 82%, and 70%, and the 1-, 3-, and 5-year tumor-free survivals of 91%, 84%, and 78% in patients with pkHCC. We concluded that patients with iHCC were more likely to be African-American, to be screened by ultrasound, to have a lower alpha-fetoprotein, and a higher MELD score. Ultrasound is not a sensitive modality for screening patients for HCC. Patients with iHCC do not have an advantage in survival over those with pkHCC.

Incidental hepatocellular carcinoma after liver transplantation: population characteristics and outcomes

We combined data from two liver transplant centers to determine the tumor characteristics and outcomes of 51 patients transplanted with incidental hepatocellular carcinoma (iHCC) compared with 143 patients transplanted for previously known HCC (pkHCC). There were no differences in age, gender, or frequency of hepatitis C infection. Patients with iHCC were more likely to be African-American (22% vs 10%; P = .016), more likely to be screened by ultrasound (38% vs 9%; P < .001), had a lower alpha-fetoprotein (83.9 +/- 258.1 vs 572.4 +/- 2376.4 ng/mL; P = .005), and had a higher model for end-stage liver disease (MELD) score (14.3 +/- 4.1 vs 11.8 +/- 4.7; P < .001). The liver explants of patients with iHCC had smaller total tumor burden than patients with pkHCC (3.1 +/- 3.5 vs 4.1 +/- 2.6 cm; P < .001), but a similar percentage of single lesions (66% vs 65%) and tumors that met Milan criteria (76% vs 65%). Patients with iHCC had 1-, 3-, and 5-year survivals of 78%, 67%, and 58%, and 1-, 3-, and 5-year recurrence-free survivals of 90%, 87%, and 87% compared with the 1-, 3-, and 5-year survivals of 90%, 82%, and 70%, and the 1-, 3-, and 5-year tumor-free survivals of 91%, 84%, and 78% in patients with pkHCC. We concluded that patients with iHCC were more likely to be African-American, to be screened by ultrasound, to have a lower alpha-fetoprotein, and a higher MELD score. Ultrasound is not a sensitive modality for screening patients for HCC. Patients with iHCC do not have an advantage in survival over those with pkHCC.

Memory consolidation and amnesia modify 5-HT6 receptors expression in rat brain: An autoradiographic study

Traditionally, the search for memory circuits has been centered on examinations of amnesic and AD patients, cerebral lesions and, neuroimaging. A complementary alternative might be the use of autoradiography with radioligands. Indeed, ex vivo autoradiographic studies offer the advantage to detect functionally active receptors altered by pharmacological tools and memory formation. Hence, herein the 5-HT(6) receptor antagonist SB-399885 and the amnesic drugs scopolamine or dizocilpine were used to manipulate memory consolidation and 5-HT(6) receptors expression was determined by using [(3)H]-SB-258585. Thus, memory consolidation was impaired in scopolamine and dizocilpine treated groups relative to control vehicle but improved it in SB-399885-treated animals. SB-399885 improved memory consolidation seems to be associated with decreased 5-HT(6) receptors expression in 15 out 17 brain areas. Scopolamine or dizocilpine decreased 5-HT(6) receptors expression in nine different brain areas and increased it in CA3 hippocampus or other eight areas, respectively. In brain areas thought to be in charge of procedural memory such basal ganglia (i.e., nucleus accumbens, caudate putamen, and fundus striate) data showed that relative to control animals amnesic groups showed diminished (scopolamine) or augmented (dizocilpine) 5-HT(6) receptor expression. SB-399885 showing improved memory displayed an intermediate expression in these same brain regions. A similar intermediate expression occurs with regard to amygdala, septum, and some cortical areas in charge of explicit memory storage. However, relative to control group amnesic and SB-399885 rats in the hippocampus, region where explicit memory is formed, showed a complex 5-HT(6) receptors expression. In conclusion, these results indicate neural circuits underlying the effects of 5-HT(6) receptor antagonists in autoshaping task and offer some general clues about cognitive processes in general.

Landfill leachate treatment using a rotating biological contactor and an upward-flow anaerobic sludge bed reactor

This paper describes the feasibility of an aerobic system (rotating biological contactor, RBC) and a biological anaerobic system (upward-flow anaerobic sludge bed reactor) at small scale for the treatment of a landfill leachate. In the first phase of the aerobic system study, a cyclic-batch RBC system was used to select perforated acetate discs among three different acetate disc configurations. These discs were chosen on the basis of high COD removal (65%) and biological stability. In the second phase, the RBC system (using four stages) was operated continuously at different hydraulic retention times (HRT), at different rotational speeds, and with varying organic concentrations of the influent leachate (2500-9000mgL(-1)). Forty percent of the total surface area of each perforated disc was submerged in the leachate. A COD removal of about 52% was obtained at an HRT of 24h and a rotational speed of 6rpm. For the anaerobic system, the reactor was evaluated with a volumetric organic load of 3273g-COD m(-3) day(-1) at an HRT of 54, 44, 39, 24 and 17h. At these conditions, the system reached COD removal efficiencies of 62%, 61%, 59%, 44% and 24%, respectively.

Follow-up of concomitant treatment with gemcitabine/radiotherapy in locally advanced squamous cell carcinoma of head and neck

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Background: The stages of the locally advanced head and neck cancer have a negative prognosis, therefore, new treatments are continuously explored. One of these treatments consists of the use of Gemcitabine concomitant with radiotherapy. We previously evaluated the rate of response and the toxicity profile of this treatment in 15 patients and now we are reporting the follow up of such study. Methods: Fifteen patients, with histological report of locally advanced squamous cell carcinoma of head and neck, initiated treatment of Gemcitabine at intravenously doses of 50 mg\m2 per application weekly concomitant with radiotherapy. The radiotherapy consisted of an initial photons dose of 3960 cGy in 22 fractions of 180 cGy to the primary site and regional lymph with posterior increments of 2880 cGy in 16 fractions of 180 cGy excluding the spinal cord and electrons increments if necessary. Results: In 9 of the 15 patients complete response was obtained, achieving organ preservation. Four of the 15 patients presented a partial response and two presented progression. The principal severe toxicity presented was mucositis. The mean follow-up is 23 months with a range of 19–27 months. From the 9 patients that presented a complete response, one presented bone recurrence 13 months after achieving the total response; another one of them died because an infectious process without evidence of tumoral activity. The rest 7 patients are to the present date without evidence of tumoral activity. One of the patients with partial response is still alive with tumoral activity in central nervous system. The remaining patients died due to tumoral activity. Conclusions: In our study with 15 patients an overall response of 87% was obtained. With a follow up to 23 months only one recurrence has been presented. We concluded that the treatment is feasible and it could have an impact in the overall survival but studies with a greater number of patients and a larger follow up are needed.

No significant financial relationships to disclose.

Presbiacusia: degeneración neuronal y envejecimiento en el receptor auditivo del ratón C57/BL6J

Presbycusis is a progressive hearing impairment associated with aging, characterized by hearing loss and a degeneration of cochlear structures. In this paper we analyze the effects of aging on the auditory system of C57/BL6J mice, with electrophysiological and morphological studies. With this aim the auditory potentials of mice aging 1, 3, 6, 9, 12, 15, 18, 21 and 24 months were recorded, and then the morphology of the cochleal were analyzed. Auditory potentials revealed an increase in wave latencies, as well as a decrease in their amplitudes during aging. Morphological results showed a total Corti's organ degeneration, being replaced by a flat epithelial layer, and a total absence of hair cells.

[Standard precautions: are these known? Are they applied?]

A study carried out among postgraduate nurses detected a high degree of confusion regarding standard precautions. This led to the formation of a multidisciplinary group from various sections of the health system to investigate this topic in greater detail. Our study observed a high degree of conceptual confusion and a lack of knowledge about standard precautions and the new recommendations regarding decontamination and hand washing in diverse health collectives. It is worrisome to detect at risk habits in relation to self-protective measures among one-third of those surveyed. Knowledge of standard precautions should be integrated with greater efficiency in the medical study programs as well as in continuing professional development programs for health professionals.

Hystological and pharmacological study of Thymus piperella (L.)

Histological and pharmacological assays have been carried out with methanol, hexane, dichloromethane and butanol extracts of Thymus piperella (L.) leaves. All the extracts were considered innocuo in the toxicity test. Methanol and also hexane, dichlorometane and butanol fractions, inhibited significantly the contractions induced by acetylcholine in isolated rat ileum in a concentration-dependent manner and the hexane extract was the most potent. However, the methanol extract did not modify the contractile effect of noradrenaline and histamine on isolated rat aorta and guinea-pig trachea respectively at the assayed dose (10, 100, 200 microg/mL). These results contribute to explain in part the use of this plant in folk medicine. In addition, morphological and histological structures characteristic of this species have been described for the first time.