Turgor loss point and vulnerability to xylem embolism predict species-specific risk of drought-induced decline of urban trees.

Increasing frequency and severity of drought events is posing risks to trees' health, including those planted in urban settlements. Drought-induced decline of urban trees negatively affects ecosystem services of urban green spaces and implies cost for maintenance and removal of plants. We aimed at identifying physiological traits that can explain and predict the species-specific vulnerability to climate change in urban habitats. We assessed the relationships between long-term risk of decline of different tree species in a medium-sized town and their key indicators of drought stress tolerance, i.e. turgor loss point (TLP) and vulnerability to xylem embolism (P50 ). Starting from 2012, the study area experienced several summer seasons with positive anomalies of temperature and negative anomalies of precipitation. This trend was coupled with increasing percentages of urban trees showing signs of crown die-back and mortality. The species-specific risk of decline was higher for species with less negative TLP and P50 values. The relationship between species-specific risk of climate change-induced decline of urban trees and key physiological indicators of drought tolerance confirms findings obtained in natural forests and highlights that TLP and P50 are useful indicators for species selection for tree plantation in towns, to mitigate negative impacts of climate change.

Refilling of embolized vessels in young stems of laurel. Do We need a new paradigm?

Recovery of hydraulic conductivity after the induction of embolisms was studied in woody stems of laurel (Laurus nobilis). Previous experiments confirming the recovery of hydraulic conductivity when xylem pressure potential was less than -1 MPa were repeated, and new experiments were done to investigate the changes in solute composition in xylem vessels during refilling. Xylem sap collected by perfusion of excised stem segments showed elevated levels of several ions during refilling. Stem segments were frozen in liquid N2 to view refilling vessels using cryoscanning electron microscopy. Vessels could be found in all three states of presumed refilling: (a) mostly water with a little air, (b) mostly air with a little water, or (c) water droplets extruding from vessel pits adjacent to living cells. Radiographic probe microanalysis of refilling vessels revealed nondetectable levels of dissolved solutes. Results are discussed in terms of proposed mechanisms of refilling in vessels while surrounding vessels were at a xylem pressure potential of less than -1 MPa. We have concluded that none of the existing paradigms explains the results.

Drought resistance of Ailanthus altissima: root hydraulics and water relations.

Drought resistance of Ailanthus altissima (Mill.) Swingle is a major factor underlying the impressively wide expansion of this species in Europe and North America. We studied the specific mechanism used by A. altissima to withstand drought by subjecting potted seedlings to four irrigation regimes. At the end of the 13-week treatment period, soil water potential was -0.05 MPa for well-watered control seedlings (W) and -0.4, -0.8 and -1.7 MPa for drought-stressed seedlings (S) in irrigation regimes S1, S2 and S3, respectively. Root and shoot biomass production did not differ significantly among the four groups. A progressively marked stomatal closure was observed in drought-stressed seedlings, leading to homeostasis of leaf water potential, which was maintained well above the turgor loss point. Root and shoot hydraulics were measured with a high-pressure flow meter. When scaled by leaf surface area, shoot hydraulic conductance did not differ among the treated seedlings, whereas root hydraulic conductance decreased by about 20% in S1 and S2 seedlings and by about 70% in S3 seedlings, with respect to the well-watered control value. Similar differences were observed when root hydraulic conductance was scaled by root surface area, suggesting that roots had become less permeable to water. Anatomical observations of root cross sections revealed that S3 seedlings had shrunken cortical cells and a multilayer endodermal-like tissue that probably impaired soil-to-root stele water transport. We conclude that A. altissima seedlings are able to withstand drought by employing a highly effective water-saving mechanism that involves reduced water loss by leaves and reduced root hydraulic conductance. This water-saving mechanism helps explain how A. altissima successfully competes with native vegetation.

[Modified radical mastectomy in local anesthesia]. / Mastectomia radicale modificata in anestesia locale.

The authors report their experience on the use of local anesthesia for modified radical mastectomy. They have used this modality in five patients who could not undergo general anesthesia because of underlying severe medical illness and in a sixth one who adamantly refused general anesthesia. They describe in detail the technique used, stressing the importance of a thorough knowledge of regional neuroanatomy. There were no complications in their small series. The authors conclude by stating that the use of local anesthesia may expand the indications for "toilet mastectomy" to include patients in poor medical condition, unsuitable for general anesthesia.

[Caroli's disease associated with cholangiocarcinoma. A case of our own observation]. / Malattia di Caroli associata a colangiocarcinoma. Un caso di nostra osservazione.

The authors report a case of Caroli's disease associated with cholangiocarcinoma. The patient presented with pain and jaundice and ultrasonography disclosed multiple common bile duct stones, cystic dilatation of the extrahepatic biliary tree and a mass in the right lobe of the liver. At operation, after a frozen section demonstrated cholangiocarcinoma, a common bile duct exploration, right hepatic lobectomy and hepato-jejunostomy were performed. They review the literature on the subject and stress the fact that hepatic tumors are associated with Caroli's disease in 7% of cases. Therefore, in these patients, when a stenosis of the biliary tree is found, multiple diagnostic manoeuvres are indicated in order to exclude the presence of malignancy.

[The Knight-Griffen technique in colorectal surgery]. / La tecnica di Knight-Griffen nella chirurgia colorettale.

The use of stapling devices has changed the practice of colorectal surgery. The authors report their experience with the "double stapling" technique introduced by Knight and Griffen in 1980 for the performance of low colorectal anastomosis. They treated 42 patients, with a mean age of 63.2 years. In 34 surgery was performed for rectal adenocarcinoma, while 8 patients were being reoperated on for closure of a colostomy after Hartmann's operation. In one patient a diverting colostomy was fashioned because of poor bowel cleansing, secondary to a stenosing rectal carcinoma. Mortality was nil. There were no clinical anastomotic leaks. There were 2 cases of late postoperative anastomotic stenosis that responded to endoscopic pneumatic dilatation.

[Rectal foreign bodies. Principles of therapy]. / Corpi estranei endorettali. Principi di terapia.

The authors report their experience with the treatment of endorectal foreign bodies (EFB). They review the literature on the subject and examine the various therapeutic options. Considering the possible complications of leaving an EFG in place for prolonged period of times in the hope of spontaneous delivery, they suggest that immediate removal is always indicated. They describe various technical modalities for endoscopic removal, that can avoid laparotomy in the majority of cases.

[Local anesthesia in anal surgery. Technical note and immediate results]. / L'anestesia locale nella chirurgia anale. Note di tecnica e risultati immediati.

The authors report their experience with the use of local anesthesia in anal surgery (hemorrhoids, anal fissures and fistulas). They describe their technique in detail, stressing the importance of thorough knowledge of the neuroanatomy of the anal canal and of a stepwise blockage of all sensory and motor fibers to the area. They report their results on 300 anal procedures performed under local anesthesia, with good patient acceptance.

[The conservative treatment of infected vascular prostheses in surgery to revascularize the lower limbs]. / Trattamento conservativo delle protesi vascolari infette nella chirurgia di rivascolarizzazione degli arti inferiori.

Infected vascular grafts are associated with very high rates of limb loss and mortality. "Classic" treatment has invariably included graft excision. Recent reports have suggested that a more conservative approach may be indicated in selected cases, leaving the graft in place and using an aggressive local treatment associated with appropriate intravenous antibiotics. The authors report their experience with two patients with infected prosthetic vascular grafts in the groin. They both had purulent drainage from the groin wound, with the graft exposed close to the femoral anastomosis. They were both treated successfully without graft removal, and both graft maintained patency, with a follow-up of 22 and 19 months.

[Intraportal air secondary to gastric dilatation. A clinical case]. / Aria intraportale secondaria a dilatazione gastrica. Un caso clinico.

The authors report a case of hepatic portal venous gas (HPVG) secondary to massive gastric dilatation in a diabetic patient following blunt trauma. Both flat plate of the abdomen and ultrasound of the liver were necessary to reach the correct diagnosis. They review the pertinent literature and stress the importance of an accurate nosologic assessment of this uncommon entity in order to avoid undue mishaps.

[Crural hernia after inguinal hernia repair. A technical note]. / Ernia crurale dopo plastica per ernia inguinale. Note di tecnica.

A case of femoral hernia following repair of an inguinal hernia with the Shouldice method is presented. The authors discuss the pathogenesis, suggest the use of ultrasound for a precise preoperative diagnosis, and propose the "plug" technique of Lichtenstein as the method of choice for the repair. This method offers a minimally invasive approach, without disturbing the previous inguinal repair and it is very simple to perform.

[Inguinal hernia surgery under local anesthesia. Technical note and immediate results]. / Plastica per ernia inguinale in anestesia locale. Note tecniche e risultati immediati.

The authors report their experience on local anesthesia for inguinal hernia repair in 164 patients. They describe the neuroanatomy of the inguinal region as well as the technique of loco-regional anesthesia. The Shouldice repair was most frequently employed, followed by the Bassini repair. Local anesthesia was very well tolerated by the patients, sometimes with the addition of mild sedation. The postoperative course was definitely shortened by the use of local anesthesia, and all patients were able to take a regular diet and to walk few hours after surgery.

[Acute intestinal infarction. Diagnostic and therapeutic problems]. / Infarto intestinale acuto. Problemi diagnostici e terapeutici.

The authors report their experience in thirteen cases of mesenteric infarction. They emphasize the difficulty in diagnosing and treating this entity, considering also the impossibility in most centers of performing emergency selective angiography of the superior mesenteric artery (SMA) When feasible, mesenteric rivascularization should always be attempted, followed 24 hours later by a "second look" procedure.

[Calculosis of the cystic duct]. / Calcolosi del confluente biliare.

The authors report on three cases of cystic duct syndrome, a fairly uncommon complication of cholelithiasis, consisting in migration of a large gallstone from the gallbladder to the common bile duct, resulting in the formation of a common cavity between cystic, hepatic and common bile ducts. They review the pathogenesis of this entity, as well as the diagnostic modalities best suited to a precise diagnosis. They stress that surgical therapy must be chosen on a case by case basis, trying to restore a functional extrahepatic biliary tree.

[Subacute Budd-Chiari syndrome treated with rTPA. Considerations on a case]. / Sindrome di Budd-Chiari subacuta trattata con rTPA. Considerazioni a proposito di un caso.

The authors report on a case of hepatic vein thrombosis or Budd-Chiari syndrome (BCS) successfully treated with recombinant Tissue Plasminogen Activator (rTPA). They briefly outline the etiology and symptomatology of this disease as well as the various surgical procedures used for treatment. Medical therapy has been so far poorly effective in treatment BCS, but recently various reports seem to indicate that rTPA may have a role. The authors suggest that rTPA may be used as the only therapy in selected cases, or in treating patients that are not candidates for surgical intervention, or as a temporizing measure to improve symptoms in patients awaiting surgery.

[Frey's syndrome: physiopathology and medical therapy]. / Sindrome di Frey: fisiopatologia e terapia medica.

Frey syndrome (gustatory sweating, auricolotemporal syndrome) is a complication of parotidectomy, probably caused by misdirection of regenerating fibers in the auricolotemporal nerve. The authors review the pathophysiology and describe the treatment used in this entity.

[Infected pseudoaneurysms of the upper limb. A case re-evaluation]. / Pseudoaneurismi infetti dell'arto superiore. Rivalutazione di un caso.

The authors report a case of infected pseudoaneurysm of the brachial artery in a drug addict, treated with aneurysm excision and brachio-brachial bypass with inverted saphenous vein. They review the literature on the subject and management options.

[Femoro-popliteal bypass with reversed saphenous vein. Experience in a General Surgery Department]. / Bypass femoro-poplitei in safena invertita. Esperienza di una divisione di chirugia generale.

Femoro popliteal bypass with reversed saphenous vein are "the gold standard" for revascularization of lower extremities with femoro popliteal occlusion. This form of therapy is usually performed in a Vascular Surgery Department. We report the experience of a General Surgery Department, with patency of 90% at two years.

[Surgical treatment of toxic megacolon]. / II trattamento chirurgico del megacolon tossico.

After an introduction on the various aetiological factors involved in toxic megacolon, its onset, medical treatment and indications to surgery, the paper describes personal experience with seven cases. The report highlights the importance of medical treatment which is recommended as the appropriate initial therapeutic approach. Then after a review of evolving surgical techniques, it is suggested , again on the basis of personal experience, that the surgical approach should be neither excessively aggressive (total proctocolectomy with permanent ileostomy) nor excessively conservative (multistoma decompression). According to this report, the operation of choice is currently subtotal colectomy plus ileostomy and sigmoidostomy which combine modest morbidity and mortality with the possibility of future reconstruction.

Spontaneous rupture of the liver.

A case of spontaneous hepatic rupture associated with bacterial cholangiohepatitis, an entity not previously described as an etiologic factor, is reported and the literature reviewed. Awareness of the pathophysiology of this process and avoidance of certain procedures are important parts of the surgical armamentarium.