Effect of critical dimension variation on SAW correlator energy.

The effect of critical dimension (CD) variation and metallization ratio on the efficiency of energy conversion of a surface acoustic wave (SAW) correlator is examined. We find that a 10% variation in the width of finger electrodes predicts only a 1% decrease in the efficiency of energy conversion. Furthermore, our model predicts that a metallization ratio of 0.74 represents an optimum value for energy extraction from the SAW by the interdigitated transducer (IDT).

Intestinal anastomosis with the biofragmentable anastomosis ring.

BACKGROUND: The fear of anastomotic complications prevents the spread of the use of the biofragmentable anastomosis ring (BAR) in intestinal surgery. PATIENTS AND METHODS: A total of 453 patients underwent intestinal resection and anastomosis with the BAR. RESULTS: In all, 514 anastomoses have been carried out, 424 (83%) in elective settings, and 90 (18%) in emergency. Fifty-one patients had multiple anastomoses. Reoperation was performed in 4 patients (1%) who had a complete anastomotic leakage. In 13 patients (3%), anastomotic leakage was partial, and only 1 patient required reoperation. No postoperative intestinal obstruction occurred. Four patients (1%) developed late anastomotic strictures, which have been treated by endoscopic dilation. CONCLUSIONS: The results of our experience and those of other large clinical series definitely confirm the effectiveness of the BAR method, which seems to be a standard, easy, rapid, and safe technique either in elective or emergency surgery.

[Use of the duodenum in demolition surgery of the stomach. Reconversion gastroduodenostomy in post-resection syndromes following Billroth II operations]. / L'utilizzazione del duodeno nella chirurgia demolitiva dello stomaco. La gastro-duodenostomia di riconversione nelle sindromi post-resezione tipo Billroth II.

Stress is laid on the importance in digestive and absorptive physiology. The methods used for the re-insertion of the duodenum in the digestive circuit in the surgical correction of servious post-Billroth II syndromes are explained. Direct duodenal reconversion by means of the transformation of gastrojejunostomy into gastroduodenostomy is recommended in the light of results obtained in 25 cases of p.o.p.u., dumping syndrome, inflammation of the anastomosis, and ALS. It is suggested that jejunal interposition should be kept for cases in which the particular shortness of the gastric stump makes simple re-insertion of the duodenum into the stomach impracticable.

[Intestinal obstruction due to Meckel's diverticulum. Description of three cases]. / Occlusione intestinale da diverticolo di Meckel. Descrizione di tre casi.

Among 588 small bowel mechanical obstructions operated since January 1982 until December 1996 at the Flajani Surgery Department and Emergency Department of the San Camillo Hospital in Rome, 3 male patients were operated for intestinal obstruction due to Meckel's diverticulum. In one case, obstruction was caused by a small bowel volvulus rolling on a Meckel's diverticulum, whose gangrenous extremity was "blocked" on caecum. In the other two cases, intestinal loops were incarcerated into an internal hernial ring constituted by the same diverticulum whose inflamed extremity was fixed to corresponding mesentery. We examined embryologic and clinical aspects of the pathology here considered, particularly its complications, obstruction being the most common in adult age. Diagnosis is often misunderstood, since a complicated Meckel's diverticulum simulates many other abdominal pathologies. A straight radiography and an ultrasonography of the abdomen may be useful to reach the correct diagnosis. We performed diverticulectomy, using a linear stapler and we underline the opportunity of this method. In young age laparoscopy resection is considered the gold treatment of this pathology by some authors. We didn't observe any mortality, although one of our patients was in a severe septic condition. It is necessary to examine the last ileal 100 centimetres when a suspected acute appendicitis is not initially found by operation. The opportunity of a promptly performed operation is underlined to prevent that such a benign pathology may induce also exitus.

[Rare neoplasms of the pancreas: the papillary-cystic tumor. A report of 2 cases]. / Neoplasie rare del pancreas: il tumore papillare-cistico. Osservazioni a proposito di due casi.

The authors report two cases of papillary-cystic tumor of the pancreas in two young women. Making a review of literature, they emphasize the rarity of this neoplasm and analyze the possible histopathologic origin, the difficult diagnosis before surgery, surgical therapy and the good prognosis of this pancreatic "curable" tumor.

[Ileorectal anastomosis with a B.A.R. A clinical case report. Bowel anastomosis ring]. / Anastomosi ileo rettale con B.A.R. Descrizione di un caso clinico.

The device invented in 1892 by Murphy is now being used again: as a matter of fact, modern technologies allowed for the development of a pressure bowel-anastomosis system with complete reabsorption, whose mechanical structure resembles Murphy's device. In 1987, in digestive anastomosis, the B.A.R. (Bowel Anastomosis Ring) pressure suturing device was successfully used. In this case report, the authors, on the basis of previous experiences concerning pressure bowel anastomosis with biodegradable material, describe the use of the B.A.R. for the performance of an ileo-rectal sub-peritoneal anastomosis in a patient with rectal neoplasia and previous ileorectostomy. In the authors' opinion, the absence of post-surgery complications and the very good functional outcome that was achieved in such a complex case, from a pathological and surgical point of view, is a further contribution to the validity of such methodology, which is also supported by several studies carried out both in the U.S.A. and in Europe on colic and upper digestive surgery. By overcoming the last hindrance represented by the performance of esophageal anastomosis, it will be possible to consider B.A.R. as a useful and proper method to be generally applied in digestive surgery.

Construction and nonclinical testing of a Puumala virus synthetic M gene-based DNA vaccine.

Puumala virus (PUUV) is a causative agent of hemorrhagic fever with renal syndrome (HFRS). Although PUUV-associated HFRS does not result in high case-fatality rates, the social and economic impact is considerable. There is no licensed vaccine or specific therapeutic to prevent or treat HFRS. Here we report the synthesis of a codon-optimized, full-length M segment open reading frame and its cloning into a DNA vaccine vector to produce the plasmid pWRG/PUU-M(s2). pWRG/PUU-M(s2) delivered by gene gun produced high-titer neutralizing antibodies in hamsters and nonhuman primates. Vaccination with pWRG/PUU-M(s2) protected hamsters against infection with PUUV but not against infection by related HFRS-associated hantaviruses. Unexpectedly, vaccination protected hamsters in a lethal disease model of Andes virus (ANDV) in the absence of ANDV cross-neutralizing antibodies. This is the first evidence that an experimental DNA vaccine for HFRS can provide protection in a hantavirus lethal disease model.

Biofragmentable anastomosis ring in emergency surgery.

BACKGROUND: The biofragmentable anastomosis ring (BAR) proved its usefulness in elective bowel surgery. AIMS: To verify the validity of the BAR in restoring bowel continuity in emergency. MATERIAL AND METHODS: The authors retrospectively evaluated the results of 62 intestinal resections and primary anastomoses with the BAR performed in 53 consecutive patients undergoing single-stage surgery for acute abdomen. No patients had either preoperative bowel preparation or intraoperative intestinal lavage. RESULTS: No proximal ileostomy or colostomy was used. A single anastomosis was made in 47 patients, while the remaining 6 patients underwent multiple intestinal resections with primary anastomoses. Forty-nine of the 53 patients had an uneventful recovery. Anastomotic leakage occurred in 2 patients (3.2%) operated on for an obstructing carcinoma of the left colon. One patient was successfully treated with a period of total parenteral nutrition, whereas the other required reoperation for a complete anastomotic leak due to failed closure of the device which was re-inserted successfully. Two patients (3.7%) died postoperatively of myocardial infarction and hepato-renal syndrome. CONCLUSIONS: Although this is a non-randomised trial, these results suggest that the BAR can be employed effectively in the emergency setting, even when single-stage intestinal surgery is performed.

The impact of routine CT of the chest on the diagnosis and management of newly diagnosed squamous cell carcinoma of the head and neck.

OBJECTIVE: The purpose of the study was to ascertain how often additional malignant neoplasms are detected on CT scans of the thorax in patients with newly diagnosed squamous cell carcinoma of the head and neck and to determine how often these findings are evident on conventional radiographs of the chest. SUBJECTS AND METHODS: One hundred eighty-nine patients with newly diagnosed squamous cell carcinoma of the head and neck were prospectively examined in a 5-year period. At the time of the initial diagnosis, each patient underwent both chest radiography (posteroanterior and lateral radiographs in 95%, anteroposterior in 5%) and thoracic CT to assess the prevalence of additional primary or metastatic malignant neoplasms of the thorax and upper abdomen. RESULTS: Of the 189 patients studied, 66 showed a total of 73 significant abnormalities on thoracic CT scans of which only 17 abnormalities (23%) were detected on chest radiographs alone. Of these 66 patients, 36 (55%) were found to have one or more primary or metastatic neoplasms. These 36 patients manifested a total of 41 additional primary or secondary malignant neoplasms including 24 cases in which one or more pulmonary nodules were detected, six cases of lymphadenopathy, three hepatic lesions, three bone lesions, two pleural masses, two esophageal masses and one adrenal mass. Of these 41 malignant tumors, 13 (32%) were synchronous primary tumors and 28 were metastases. Only 12 (29%) of the 41 malignant tumors detected by thoracic CT were seen on the chest radiographs. In all patients in which an additional malignant tumor was diagnosed, clinical management was significantly affected, resulting in a modification of the planned surgery or the addition of chemotherapy, radiation therapy, or both. CONCLUSION: A relatively large percentage of patients (19%) with newly diagnosed squamous cell cancer of the head and neck was found to have additional malignant tumors, 32% of which were synchronous primary tumors. The discovery of these additional neoplasms had a major effect on both the therapy and the prognosis of these patients. The combination of a relatively poor detection rate for conventional chest radiography, with only 29% of the malignant tumors detected on CT scans of the chest being seen on chest radiographs, and the high prevalence of disease in this population support the routine inclusion of thoracic CT in these patients.