Nestmate recognition in Parischnogaster striatula (Hymenoptera Stenogastrinae), visual and olfactory recognition cues.

The recognition of nestmates from alien individuals is a well known phenomenon in social insects. In the stenogastrine wasp Parischnogaster striatula, we investigated the ability of females to recognize nestmates and the cues on which such recognition is based. Recognition of nestmates was observed in naturally occurring interactions between wasps approaching a nest and the resident females on that nest. This recognition was confirmed in experiments in which nestmates or alien conspecifics were presented to resident females. In naturally occurring interactions, nestmates generally approach their nest with a direct flight, while aliens usually hover in front of the nest before landing. In experiments in which the presented wasps were placed close to the nest in a direct manner, antennation of the presented wasp generally occurred, indicating that chemical cues are involved. Experiments in which dead alien individuals, previously washed in hexane, and then reapplied with extracts were recognized by colonies giving further evidence that chemical cues mediate nestmate recognition. Epicuticular lipids, known to be nestmate recognition cues in social insects, were chemically analysed by GC-MS for 44 P. striatula females from two different populations (13 different colonies). Discriminant analysis was performed on the data for the lipid mixture composition. The discriminant model showed that, in the samples from these two populations, 68.2% and 81.9% of the specimens could be correctly assigned to their colony.

Replacement of the entire thoracic aorta according to the reversed Elephant Trunk technique.

The aim of this work is to present our modified Elephant Trunk technique to reduce circulatory arrest time and consequently mortality and morbidity rates. According to Borst's technique the ascending aorta and aortic arch are replaced first, under deep hypothermic circulatory arrest, while a graft segment is left in the descending thoracic aorta. In the second stage of the operation, the descending thoracic aorta is replaced through left thoracotomy using this graft segment. In our modified technique, after the flexion in the proximal segment of the graft, the descending thoracic aorta is replaced first through left thoracotomy in Bio-Pump protection, choosing the best aortic segment for proximal anastomosis. In the second stage we replace the ascending aorta and the aortic arch using the graft and applying Carrel patch anastamosis only to the epiaortic vessels, under deep hypothermic circulatory arrest. It is our opinion that the mortality incidence of this technique is similar to that obtained with Borst's technique, though certainly inferior to the one stage procedure , while the morbidity results are better than those obtained with the Borst Elephant Trunk technique and with the one stage procedure. In fact there are fewer stroke incidents thanks to the reduced times of deep hypothermic circulatory arrest, and fewer postoperative bleedings and respiratory failures thanks to the reduced times of the total cardiopulmonary bypass. At the beginning we used this technique to replace symptomatic aneurysms, covered ruptures, and hematomas of the wall of the descending thoracic aorta, which required replacement of the descending thoracic aorta first; we later extended the treatment to all types of thoracic aorta aneurysms.

Repair of thoracoabdominal aneurysms with minimal diaphragmatic section.

We describe here use of a minimal diaphragmatic section in thoracoabdominal aneurysm surgery, for patients with chronic obstructive lung disease and a history of cigarette smoking. The diaphragmatic section of about 10 cm that concerns only the muscle is taken circumferentially; this does not damage the phrenic nerve and enables quick respiratory recovery in the postoperative period. This procedure is easy to use, whether through thoracoabdominal aorta substitution or reimplantation of the intercostal arteries and visceral vessels. This technique can be useful in extending surgical treatment to patients with respiratory failure.

Aortobronchial fistula after aortic dissection type B.

Although rare, aortobronchial fistula complicates thoracic aortic surgery. Correct diagnosis and the infectious nature of the lesion are the most important conditions to define, for the following best therapy. We presented a case of non-infectious postsurgical aortobronchial fistula, revealed by computed-tomographic scan and angiography procedure, treated with prosthetic graft replacement and broad spectrum antibiotic therapy. In the case of infection our policy is homograft replacement. Computed tomography, being able to make diagnosis, should be performed as the initial technique.

Type III dissection according to DeBakey. Comments on 45 cases treated.

BACKGROUND: There is uncertainty regarding the most suitable form of treatment for both chronic and even more so the acute forms of DeBakey's type III aortic dissections. This retrospective study analyses the indications and methods used in 20 acute cases and 25 chronic cases of type III dissection. METHOD: The 45 patients included in this study presented a high index of operability given that they were selected from more than one coronary unit and referred to our service for this purpose. This study also confirmed a clear indication for medical treatment in uncomplicated acute forms, whereas it is necessary to opt for surgery in the case of ongoing or threatened complications. In chronic forms aorta diameter and/or thrombosis of the false lumen are a valid parameter. RESULTS: The incidence of mortality was 33.3% in the 12 acute forms undergoing surgery, with 4 deaths; in the case of chronic forms undergoing surgery, the incidence was 15% with 3 deaths. Of the 8 patients with acute pathology who were not operated, 87.5% died; whereas of the 5 non-operated chronic patients, 60% died (3 cases). During the post-operative period rethoracotomy was only necessary in 1 case following hemothorax on day 5, whereas at a respiratory level only 50% of patients were extubated within 48 hours, and in 12 cases it was necessary to continue until day 5-7, whereas tracheostomy was performed in 5 cases. CONCLUSIONS: The modern tendency in the treatment of DeBakey's type III acute dissections is to opt for surgery not only in the presence of manifest complications, but also when faced with threatened complications or the failure of medical treatment. Chronic forms present the two key indications for surgery, namely aneurysmatic evolution of the wall (> 5-6 cm) and absent thrombosis of the false lumen.

Aortic arch aneurysms: surgical results and follow up in 56 patients.

From January 1989 to December 1994, 56 patients, 43 male and 13 female, mean age 61.21 +/- 10.05 years, underwent surgical procedures on the aortic arch at our institution. Forty-six patients underwent emergency or urgent operations, fourty-four of them presented acute aortic dissections involving the aortic arch. All operations were performed in cardiopulmonary by-pass, 39 operations in deep hypothermic circulatory arrest, 10 in deep hypothermic circulatory arrest and hypothermic retrograde cerebral perfusion. The overall hospital mortality was 17.9% (10 patients). The main causes of hospital mortality were: multiorgan failure (3 patients) and major neurological damage (2 patients). In the group of patients that underwent hypothermic retrograde cerebral perfusion there was no major neurological damage. In the follow up there were no deaths and 4 reoperations related to the aortic pathology. The cerebral protection represents the main problem in the aortic arch surgery. The deep hypothermic circulatory arrest is an effective method to reduce the cerebral and visceral ischemia, in particular in acute dissection; nevertheless this method leads to more bleeding complications and lengthening of the cardiopulmonary bypass in time. In our experience, the hypothermic retrograde cerebral perfusion associated with deep hypothermic circulatory arrest appears to be a useful method to prevent cerebral damage. However this procedure needs further investigation.

The dacron aorta.

Total aorta replacement is a major and increasingly successful surgical procedure. The paper describes a patient whose progressive aneursymatic disease spread from the ascending segment to the bifurcation over a three-years period during which time after three separate operations, the aorta was totally replaced. The paper describes the diagnostic and surgical procedures deployed and shows the results of angiographic and CT scans. Credit for the success of the replacement is also given to the highly skilled anaesthetists and nurses involved.

[Surgery of the descending thoracic and thoraco-abdominal arteries. Report of 105 cases]. / La chirurgia dell'aorta toracica discendente e toraco-addominale. A proposito di 105 casi.

The Authors show their casistic of about 105 cases of thoracic descending and thoraco-abdominal aorta pathologies between 1.1.1993 and 30.12.1995. After a short introduction about the improvements in anesthesia and reanimation of these pathologies as well as the good reliability of diagnostic and currently available instruments, mortality and mobility parameters are taken into account, the last one referring to paraplegia and ARF. The casistic is evaluated splitting the cases into 2 groups, urgent surgery and election surgery, and differentiating the aneurysm type from the dissection type. Besides, the mortality and mobility are reported for any pathology, with a discussion of the parameters which drove the choice of the most suitable methodology to be adopted (ECC femoro-subclavian shunt, simple clamping). The results achieved show a mortality of 40% in urgency, between 5 and 15% in election, with a rate of paraplegia around 8-10% and a ARF between 5 and 15%. These data match the literature statistics and support the quality of the adopted methodologies.

[The superior vena cava occlusion syndrome. A case of neoplastic thrombosis due to hepatocarcinoma and cirrhosis]. / Sindrome da occlusione della vena cava superiore. Su di un caso di trombosi neoplastica da epatocarcinoma su cirrosi.

The authors report their experience with 11 patients, surgically treated since 1990, affected with superior vena cava syndrome. A peculiar case of neoplastic thrombosis in hepatocarcinoma is stressed. In fact a similar case hadn't been reported in the last ten-year literature, although hepatocarcinoma may spread in different organs. A subject review and a discussion are presented.

Surgical treatment of carotid kinking.

The authors take in exam 34 anatomical variation in the extracranial internal carotid artery (compared with more than 450 operated carotid artery), 15 of which involved kinking in patients with overt neurological symptoms, underwent corrective surgical treatment, and test the most useful and appropriate techniques in any case.

Transglutaminase activity is related to CAG repeat length in patients with Huntington's disease.

Huntington's disease (HD) is a neurodegenerative disorder associated with CAG repeat expansion. We measured transglutaminase (TGase) activity in lymphocytes from 35 HD patients and from healthy individuals to ascertain whether it was altered in this condition. TGase activity was above maximum control levels in 25% of HD patients; it was correlated with the age of the patient and inversely correlated with the CAG repeat length. These results suggest that: (1) HD could be biochemically heterogeneous, and (2) the length of the CAG repeat expansion/TGase ratio could be important in the manifestation of HD.

[Spinal cord protection in surgery of the thoracic, descending, and thoraco-abdominal aorta. Comparison of methods]. / La protezione midollare nella chirurgia dell'aorta toracica, discendente e toraco-addominale. Metodiche a confronto.

The authors compare the strategus needed for the elimination of paraplegia and for protection of abdominal organs after replacement of descending thoracic or thoraco-abdominal aorta. They analyse single technique considering the advantages and the controindications; furthermore they compare these properties and those of possible variants in the light of the presentation; type of disease and general conditions of the patient. These considerations are in agreement with later literature as well as the attitude of the surgeon.

[Pseudoaneurysms after carotid endarterectomy]. / I pseudoaneurismi postendoarterectomia carotidea.

Pseudoaneurysms after TEA of the internal carotid artery are one of the rarest and most severe complications of this form of surgery. Their etiology appears to depend on 3 causes: a suturing defect due to technical errors made by the surgeon or to the incorrect choice of threads; an infections, and lastly the arterial wall weakened by TEA. The patch increases the risk of false aneurysm approximately four fold. We therefore agree with other authors that, in spite of the undoubted value of the patch in the prevention of restenosis, it must only be used in the presence of an internal carotid of small diameter (less than 4 mm). Contrary to what is reported in the literature we performed both these operations under loco-regional anesthesia and a detailed knowledge of this method allows is to be performed on the carotid axis. Only through a careful follow-up of all the carotids operated can the small dilations which often do not require surgical treatmente identified. The two cases reported here were treated by the removal of the pseudoaneurysms and its replacement with a prosthesis in one case and with the vena saphena in the other. Both were monitored with clinical examination and echo-Doppler and no recidivation has been reported to date.

[Invasion of the chest wall in primary lung neoplasms]. / L'invasione della parete toracica nelle neoplasie polmonari primitive.

The authors analyse a series of 5 patients who underwent pulmonary and parietal resection between 1990 and 1993 due to non.microcytoma bronchogenic carcinoma with invasion of the thoracic wall. The patients comprised four men and one woman aged between 45 and 69 years old. Thoracic pain was present in two patients. Pulmonary resection with extrapleural stripping was performed in two patients whereas a block resection from one to five ribs and the corresponding intercostal spaces was performed in the other three patients. The authors' approach is not to perform these operations according to rigid protocols but to adapt them according to the local status of tumour invasion. Therefore to resort to extrapleural resection when there is a free cleavage plane between parietal pleura and rib wall; resection in block of the wall where the carcinoma has infiltrated the endothoracic fascia or deeper. The authors do not report any major complications and record a postoperative mortality rate of 0%. In two cases the thoracic wall was reconstructed using a sheet of Gore-Tex which did not provoke rejection phenomena. Radiotherapy was carried out in cases with positive lymph nodes. The series presented here is too recent to provide significant data regarding survival. However, the only factor seen to influence prognosis in the five patients was the presence or otherwise of lymph node metastasis, irrespective of the histological type and operation performed. The five year survival rate of T3N0M0 patients is in fact similar to that of T2N0M0 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Realities and limitations of the diagnosis of erectile impotence: radical urethro-prostato-cystectomy as a human experimentalmodel]. / Attualità e limiti della diagnostica nell'impotenza erettile: la uretro-prostato-cistectomia radicale come modello sperimentale umano.

Veno-occlusive dysfunction (formerly called "venous leakage") is a clinical-radiographic manifestation of a multi-aetiology syndrome, the pathogenesis of which is to be sought in intrinsic damage to the erectile tissue. It has been attributed to psycho-neurogenic, neurovascular and local--physical factors. The unsatisfactory results of the various surgical techniques proposed (venous ligatures, crural plication, corporopexy) can be explained by the formation of vicarious venous circles, a phenomenon which occurs regardless of the type of procedure adopted and which is the direct consequence of the alteration of the occlusive mechanisms intrinsic to the erectile tissue. At the Urological Institute of the University of Milan, a study has been carried out with the aim of experimentally assessing these aetiopathogenetic hypotheses. 48 sexually potent patients were selected from those scheduled for extensive surgical procedures on account of malignant pathologies of the pelvic cavity (urethro-prostato-cystectomy, radical prostatectomy). The protocol included a series of examinations before and after the operation (at three months): computerised recording of nocturnal erections (NPT test, three consecutive nights), dynamic penile Doppler velocimetry, dynamic cavernosometry/graphy, examination of bulbocavernosus reflex. The goal of the study was to evaluate the haemodynamic consequences of the massive venous ligatures effected during these operations (periprostatic plexus, deep dorsal vein, spongio-cavernous connections). There were 28 cases of radical prostatectomy and 20 cases of radical urethro-prostato-cystectomy. Among the cases of radical prostatectomy, the extrafascial retropubic technique was used for 14 patients, the monolateral nerve-sparing procedure was applied for 10 patients (stage B1) and the transperineal approach was used for 4 patients (the most recent).(ABSTRACT TRUNCATED AT 250 WORDS)

[Hepatic resection. A contribution and its analysis]. / Resezioni epatiche. Un contributo e la sua analisi.

The authors outline their experience in the field of resective hepatic surgery, both with regard to benign and malignant pathologies, and analyse the results in relation to indications and techniques, but also focusing attention on the assessment of postoperative functional alterations, in order to evaluate the hepatic reserve and the organ's response to demolitive surgery. All operations were carried put in the First Division of Surgery at the Ospedale Civile, Asti, from January 1989 to September 1992. In all cases, even in major hepatectomies, a "trans-parenchymal" technique was adopted. Before surgery tests were carried out in relation to the topography of disease, its nature, associated pathologies and the functional hepatic reserve. Operative mortality was zero and morbidity was negligible, probably because rigorous selection criteria and indications for surgery were adopted. Morbidity was even restricted in the two patients suffering from HCC on cirrhosis (?) and this may probably be attributed to the limitation of resection to solely oncological purposes and their classification as Child-Pugh's stage A. The results regarding the liver response to demolitive surgery appear to be indicative and revealed a highly significant and discriminating difference between elective and emergency surgery.

[Major and minor complications in carotid surgery]. / Complicanze maggiori e minori in chirurgia carotidea.

The Authors report their experience of major and minor complications in carotid surgery. They analyse the causes and emphasize that a thorough preoperative study and a quick surgical technique are very important in reducing the rate of complications in this essentially preventive form of surgery.

[Surgical treatment of liver metastases of colorectal carcinoma. Our experience and review of the literature]. / Il trattamento chirurgico delle metastasi epatiche da ca. colo-rettale. Nostra esperienza e revisione della letteratura.

The authors describe their personal experience of the surgical treatment of hepatic MTS caused by colon-rectum ca. Following a review of the literature, including therapeutic protocols which do not always agreed, the problems inherent to the number, site, size and appearance of MTS themselves are discussed. Different approaches are compared in an attempt to clarify this pathology about which still very little is known. There is often uncertainty regarding the cases which should be treated surgically, and there is certainly a need for a greater number of case studies so as to avoid relying on the sensitivity and experience of the individual surgeon.

[Parietal damage in intestinal infarction. Clinical and anatomo-pathological considerations]. / Il danno parietale nell'infarto intestinale. Considerazioni anatomo-patologiche e cliniche.

The physiopathology of parietal damage due to acute ischaemia is reviewed on the basis of a personal series of more than 70 cases. The reported data (not particularly abundant) is examined and an attempt made to draw conclusions that, free from mere theoretical and abstract value, may materially help the surgeon in his by no means easy decision to revascularize or resect an intestinal segment.

[Reimplantation of the inferior mesenteric artery during surgery of abdominal aortic aneurysm. Current trends]. / Il reimpianto dell'arteria mesenterica inferiore nella chirurgia dell'aneurisma aortico addominale. Moderni orientamenti.

After a review of world literature and on the basis of personal experience, the problem of ischaemic colitis following abdominal aortic aneurysmectomy is examined. After remarks on the aetiopathogenesis and clinical picture of the condition the paper stresses the need for early detection of patients at high risk, to prevent a clinical picture that is insidious but serious and tends to develop rapidly. The use of preoperative angiography to study the SMA and IMA as well as intraoperative stump-pressure measurement is considered essential. The paper concludes that ischaemic colitis following abdominal aortic reconstruction can be avoided in a large percentage of cases by IMA implantation on the Dacron prosthesis, a surgical technique that is easy and not time-consuming.