Effect of freeze time during renal cryoablation: a swine model

BACKGROUND AND PURPOSE: Cryotherapy provides a minimally invasive treatment for small renal tumors via an open, percutaneous, or laparoscopic approach. We sought to determine the most appropriate duration of freezing and the number of probes necessary to produce cell death without concomitant morbidity. MATERIALS AND METHODS: Nine domestic female pigs were divided into three groups of three animals each. Each group underwent a single freeze cycle with a commercially available cryotherapy device with 3.4-mm probes: group 1 for 5 minutes, group 2 for 10 minutes, and group 3 for 15 minutes. The right kidney was treated with a single probe, the left with a double probe. Animals were permitted to survive for an average of 4.8 days (range 4-7 days), after which the kidneys were harvested. A single pathologist examined the kidneys for gross and histologic changes. Evidence of complications (fistula, bleeding, bowel injury) was documented at the time of necropsy. RESULTS: For group 1, the temperature obtained with a single probe 5, 10, 15, and 20 mm from the probe was -57 degrees C, 3 degrees C, 25 degrees C, and 33 degrees C, respectively; for group 2 -85 degrees C, -37 degrees C, -2 degrees C, and 25 degrees C; and for group 3 -10 degrees C, -45 degrees C, -20 degrees C, and 6 degrees C. For group 1, the temperature obtained with a double probe at 5, 10, 15, and 20 mm from each probe was -65 degrees C, 0 degrees C, 20 degrees C, and 30 degrees C, respectively; for group 2 -72 degrees C, -25 degrees C, 5 degrees C, 25 degrees C; and for Group 3 -82 degrees C, -30 degrees C, -12 degrees C, 13 degrees C. Complete necrosis was seen 5 mm from the cryoprobe within each group, but only in groups 2 and 3 did necrosis extend 10 mm or beyond the probes when utilizing either single or double probes. The maximum diameter of consistent necrosis was 35 to 40 mm in the animals in group 3 treated with a double probe. Bleeding and renal fracture were the two most common complications. CONCLUSIONS: A 5-minute freeze appears to be inadequate to cause tissue necrosis and is associated with excessive bleeding at the time of the procedure, whereas the 15-minute freeze produces consistent necrosis but is associated with renal fracture. In this animal model, the 10-minute freeze with the single or double probe configuration appears optimal to produce necrosis without complications.     

Identification and rapid determination of the antibiotic resistance of enterobacteria with the automated ABAC identibiogram

Rapid identification and antimicrobial testing of Enterobacteriaceae by an automated system, the ABAC-Identibiogramme. The system was directly inoculated with a dilution of positive blood culture broths. The results were compared with those of API 20E and the disk method for antibiogram. The ratios of agreement of 94.5% for identification and of 93.4% for antimicrobial testing demonstrate a good accuracy of the ABAC-Identibiogramme.     

Retrovirus-mediated correction of the metabolic defect in cultured Farber disease cells.

Farber disease is a rare severe lysosomal storage disorder due to a deficient activity of the enzyme acid ceramidase (AC). Patients have granulomas along with lipid-laden macrophages that accumulate in a number of tissues, leading to multiple diverse clinical symptoms. There is no therapy for the disorder and most patients succumb to the disease in early childhood. The severity of the disease progression seems to correlate with the amount of the accumulated ceramide substrate. Since the cDNA for human AC has been elucidated we sought to establish if genetic transfer of this sequence would lead to enzymatic and, especially, functional correction of the catabolic defect in Farber patient cells. To do this, a novel amphotropic recombinant retrovirus was constructed that engineers transfer of the human AC cDNA. On infection of patient fibroblasts, AC enzyme activity in cell extracts was completely restored. Further, substrate-loading assays of intact living cells showed a fully normalized catabolism of lysosomal ceramide. Lastly, as reported for some other corrected enzymatic defects of lysosomes, metabolic cooperativity was seen, in that functionally corrected patient fibroblasts secreted AC that was taken up through the mannose 6-phosphate receptor and used by uncorrected fibroblasts as well as recipient Farber lymphoblastoid cells. This overall transduction and uptake scenario for Farber disease allows future treatment of this severe disorder to be envisioned using gene transfer approaches.     

Analysis of ureteric stent kinking forces: the role of curvature in stent failure

OBJECTIVE

To further characterize the kinking forces and degree of curvature that result in failure of various stents, as malignant obstruction of the ureter causes failure of about half of ureteric stents.

MATERIALS AND METHODS

Several stents (Silhouette 4.6 F and 6 F, Applied Medical, Rancho Santa Margarita, CA; Sof‐Curl^TM Tecoflex 6 F, Gyrus ACMI, Southborough, MA; Polaris^TM Ultra 6 and 7 F, and Percuflex® 6, 7 and 8 F stents, Boston Scientific, Natick, MA, USA) were tested. The amount of force necessary to result in kinking of the stent was measured, and the degree of curvature at failure was calculated for each stent.

RESULTS

The Silhouette 4.6 and 6 F stents were the most resistant to failure by kinking and curvature. In general, smaller stents allowed more curvature before failing than their larger counterparts.

CONCLUSIONS

The greater allowable curvature and resistance to kinking achieved by the Silhouette ureteric stents might result in fewer stent failures in cases of malignant obstruction or other retroperitoneal processes.     

Utility of serum tumor markers as an aid in the differential diagnosis of patients with clinical suspicion of cancer and in patients with cancer of unknown primary site

Cancer may be diagnosed in advanced stages, when the patient has already developed metastasis, with symptoms that can be also observed in benign diseases. The objective of this study was to evaluate tumor marker sensitivity and specificity in the differential diagnosis of patients with suspected signs of cancer. We studied 2.711 consecutive patients admitted to the Internal Medicine Department of our hospital with suspected cancer; 1.240 patients had non-malignant processes and 1.471 had malignant disease. Determinations were considered positive for suspected malignancy when serum levels were carcinoembryonic antigen >15 ng/ml (>20 in patients with renal failure or liver disease), alpha fetoprotein >40 ng/ml (>80 ng/ml in patients with liver diseases), carbohydrate antigen (CA) 19.9 > 200 U/ml (>500 U/ml in patients with liver diseases or gamma glutamyl transpeptidase (GGT) <150 UI/L or effusions; >1.000 U/ml in patients with jaundice or GGT > 150 UI/L), neuron-specific enolase >45 ng/ml (renal failure >50 ng/ml; samples with hemolysis were excluded), prostate-specific antigen > 30 ng/ml (excluding acute prostatitis), tumor-associated glycoprotein-72 >80 U/ml, cytokeratin 19 fragment 21-1 > 7.5 ng/ml (>19 ng/ml in patients with renal failure; >11 ng/ml in patients with liver cirrhosis or jaundice), >3.5 ng/ml for squamous cell carcinoma (excluding patients with renal failure or skin disorders), CA 15.3 >100 U/ml, and CA 125 >350 U/ml (>600 U/ml in patients with pleural effusion and >900 U/ml in those with ascites). There was a specificity of 97.6% in patients without malignancy, 67.4% of sensitivity in patients with malignancy, and 75.4% of sensitivity in the 1,280 patients with epithelial tumors (53.7% in patients with locally advanced tumors and 79.4% in patients with metastases). Sensitivity was 81.4% in patients with cancer of unknown primary site. Tumor markers were useful in the differential diagnosis between epithelial and non-epithelial tumors, brain masses (metastases vs. primary tumors), and between benign or malignant origin of different clinical situations such as wasting syndrome, effusions, liver or bone lesions, and effusions with a positive predictive value higher than 95%. Tumor markers are useful as an aid in the evaluation of the risk of cancer of these patients with suspected cancer and may be useful to reduce the hospitalization time, morbidity, and the number of diagnostic tests required for diagnosis.     

Cutaneous Crohn''s disease mimicking Melkersson–Rosenthal syndrome: treatment with methotrexate

A woman with a 5-year history of unilateral orofacial granulomatosis required repeated evaluations (including sequential colonoscopies) to establish the diagnosis of cutaneous Crohn's disease, a condition that proved responsive to low doses of oral methotrexate administered weekly. To our knowledge this is the first report describing the use of methotrexate for treatment of orofacial granulomatosis caused by underlying Crohn's disease.     

Naevus lipomatosus cutaneous superficialis

A young male presenting with cutaneous papules and plaques in a segmental distribution in the pelvic girdle area is reported. The clinical features were suggestive of naevus lipomatosus cutaneous superficialis, but diagnostic biopsy is essential to demonstrate the typical histopathological features and exclude important differential diagnoses such as segmental neurofibromatosis.