Formation of zeolite-like zinc 1,3,5-benzenetriphosphonate open-frameworks by topotactic pillaring of anionic layers.

An ab initio powder X-ray crystal structure analysis revealed that layered zinc 1,3,5-benzenetriphosphonates containing interlayer tetramethylammonium (ZBP-TMA) or 4,4'-bipyridinium cations (ZBP-bpy) are transformed to novel isomorphous 3D open-framework compounds ZBP-M (M: K, Rb, and Cs) by treatment in aqueous alkali metal chloride solutions. ZBP-Ms have a pillared layer-type of anionic framework containing 2D zigzag channels connected with cage-like spaces. The potassium atoms in ZBP-K are located near 8MR windows in the 2D zigzag channels, and the potassium cations are successfully exchanged with ammonium cations retaining the open-framework structure. The ammonium form (ZBP-NH4) showed remarkable cation exchange selectivity for Rb(+) and Cs(+) in a mixture of alkali metal cations. It is assumed that zinc ions partially dissolved from the starting layered ZBP precursors are intercalated in ZBP layers to form pillared layered 3D open-frameworks. These results clearly show that topotactic pillared layer approaches are applicable not only to zeolite-related materials but also to novel open-framework metal organophosphonates.

Laparoscopic resection of hilar cholangiocarcinoma.

BACKGROUND: Surgical resection is the only curative treatment for hilar cholangiocarcinoma. Laparoscopic hepatectomy has been used to treat several types of liver neoplasms. However, technical issues have limited the adoption of laparoscopy for the treatment of hilar cholangiocarcinoma. To date there is only one report of minimally invasive procedure for hilar cholangiocarcinoma in the literature. The present video-assisted procedure shows a laparoscopic resection of hilar cholangiocarcinoma. PATIENT AND METHODS: A 43-year-old woman with progressive jaundice due to left-sided hilar cholangiocarcinoma was referred for treatment. The decision was to perform a laparoscopic left hepatectomy with lymphadenectomy and resection of extrahepatic bile ducts. Biliary reconstruction was performed using the hybrid method. RESULTS: Operative time was 300 minutes with minimum blood loss and no need for blood transfusion. Recovery was uneventful, and the patient was discharged on postoperative Day 7. Pathology revealed a well-differentiated cholangiocarcinoma with negative lymph nodes and clear surgical margins. The patient is well with no signs of the disease 18 months after the procedure. CONCLUSIONS: Laparoscopic left hepatectomy with lymphadenectomy is safe and feasible in selected patients and when performed by surgeons with expertise in liver surgery and minimally invasive techniques. The use of a hybrid method may be needed for biliary reconstruction, especially in cases where position and size of remnant bile ducts may jeopardize the anastomosis. Further studies are still needed to confirm the benefit of this approach over conventional surgery for hilar cholangiocarcinoma.

Intestinal ischemia as a single manifestation of thromboangiitis obliterans--a case report.

Thromboangiitis obliterans (TAO) is an inflammatory, nonocclusive, and nonatherosclerotic vascular disease. It commonly affects arteries, veins, and surrounding neural elements and is directly related to smoking. Although distal vessels of lower and upper extremities are the most commonly involved, other vessels such as intestinal arteries can be rarely affected. The authors describe a 41-year-old white male smoker who presented with abdominal pain for 3 months and developed an acute bowel ischemia. He underwent urgent surgery, and segmental enterectomy was performed. Histopathologic findings were suggestive of TAO, showing typical involvement of small-sized veins and arteries with intact internal elastic lamina, preserved media, a local nonspecific inflammatory reaction, with new and older arterial and venous thromboses associated. Although mesenteric arteries are seldom injured by TAO, this diagnosis must be considered when the usual causes of intestinal ischemia are ruled out. In this case, even without any other clinical symptoms of TAO, this rare diagnosis could be made.

[Effect of guided adhesions on ischemic colic anastomoses in rats]. / Efeito de aderências dirigidas em anastomoses cólicas isquêmicas em ratos.

PURPOSE: Evaluate the effect of conducted adhesions on the mechanical resistance of anastomoses performed in ischemic colon through the Bursting Strength Test and Breaking Strength Test. METHODS: Forty rats were divided into two groups. Group 1 was composed of 20 rats in which the anastomoses were covered with P.V.C. (Polyvinyl Chloride) to prevent the occurrence of adhesions over the anastomotic line. Group 2 was composed of 20 rats in which anastomotic line was covered with epididimal fat besides P.V.C. to prevent formation of other adhesions. RESULTS: The mean Bursting Strength of the anastomoses in the group without adhesion was 10 mmHg and this value was 55.2 mmHg in the group with adhesion (p < 0.05). The mean Breaking Strength of the anastomoses was 142.5 gf in the group without adhesion and 262 gf in the group with adhesion (p < 0.05). CONCLUSION: Based on those mechanical tests, adhesions were benefic to ischemic anastomoses, rising their intrinsic resistance both on Bursting and Breaking Strength.

Efeito de aderências dirigidas em anastomoses cólicas isquêmicas em ratos / Effect of conducted adhesions on ischemic colic anastomoses in rats

OBJETIVO: Avaliar o efeito das aderências dirigidas sobre a resistência mecânica de anastomoses realizadas em cólon isquêmico através da aplicação dos testes Resistência à Pressão de Explosão e Resistência à Força de Tração. MÉTODOS: Quarenta ratos foram distribuídos igualmente em dois grupos. O Grupo 1 era constituído de vinte animais em que as anastomoses cólicas isquêmicas foram recobertas por uma película de polivinilcloreto (P.V.C.) para impedir a formação de aderências sobre as linhas de sutura e o Grupo 2 era constituído por 20 animais em que as anastomoses cólicas isquêmicas foram recobertas pela gordura epididimal, de forma a constituir uma aderência dirigida sobre a linha de sutura, sendo ainda recobertas por uma película de P.V.C. para impedir a formação de outras aderências. RESULTADOS: A média da Pressão de Ruptura à Distensão por Líquidos da anastomose foi de 10 mmHg no grupo sem aderência e de 55,2 mmHg no grupo com aderência (p < 0,05). A média da Força de Ruptura à Tração das anastomoses foi de 142,5 gf no grupo sem aderências e de 262 gf no grupo com aderência (p < 0,05). CONCLUSÃO: As aderências mostraram ser benéficas, elevando a resistência intrínseca das anastomoses tanto na Resistência à Distensão por Líquido quanto na Resistência à Força de Tração.

Associação entre megacólon chagásico e câncer do intestino grosso: apresentação de casos e revisão da literatura / The association between chagasic megacolon and colorectal cancer: presentation of cases and revision of literature

Contrariamente ao megaesôfago, parece ser incomum a associação entre megacólon chagásico e câncer colorretal. Na literatura consultada foram descritos 8 casos, aos quais os autores acrescentam outros 4 de sua experiência. A localização dos tumores vai do ceco ao reto. Ocorreram adenomas em 5 pacientes, sendo 3 destes pertencentes a esta casuística. Há descrito um caso de associação com polipose adenomatosa familiar. A associação relativamente elevada com adenoma faz supor a existência de população cujos riscos sobrepujaram a proteção conferida pela ectasia. O prognóstico parece ser pior.