Inducción de fenotipo presentador de antígenos y apoptosis en células de leucemia linfática crónica B incubadas con oligodeoxinucleótidos sintéticos con motivos PyNTTTTGT (IMT504) / Phenotype´s induction presenter of antigens and apoptosis in cells of incubated lymphatic leukemia chronic B with oligodeoxynucleotides synthetics with PyNTTTTGT(IMT504) reasons

Introducción: El sistema inmune no es capaz de reconocer los cambios en células transformadas por mutaciones en la leucemia linfática crónica de estirpe B (LLC-B). Su incubación con linfocitos autólogos no induce citotoxicidad. Puede deberse a la ausencia de linfocitos T citotóxicos o a la incapacidad de las células de LLC en expresar moléculas coestimulatorias (CD80, CD86), a pesar de tener expresión de HLA clase I y II. El ADN bacteriano y los ODNs que contienen motivos PyNTTrrGT, CpG y otros motivos, pueden activar a los monocitos, las células dendríticas y los linfocitos B. Aparte, algunos ODNs tienen efectos directos sobre las células LLC-B. Material y métodos: se incubaron células leucémicas provenientes de 20 pts. con LLC-B con 3 diferentes ODNs: a) IMT504, con motivos PyNTTrrGT b) 2006 con motivos CpG y c) ODN inactivo de control. Previo y posterior a la incubación se efectuaron determinaciones de CD80, CD86, CD40, MHC clase I y II, CD5, CD19 y CD20 por citometría de flujo. Además se determinó (por medio de la detección de fosfatidilserina por la unión ala Anexina V) la capacidad de inducir la apotosis de las células transformadas, y se estudió la morfología de las células en cultivo. Resultados: Se observó el aumento de la detección de fosfatidilserina por la unión ala Anexina V) la capacidad de inducir la apotosis de las células transformadas, y se estudió la morfología de las células en cultivo. Resultados: Se observó el aumento de la expresión de CD80, CD86 y CD40 en las células incubadas con IMT504 y 2006. Además las células LLC-B expresaron significativamente mayor cantidad de Anexina v. La morfología de las células en cultivo a largo plazo mostró las características de apoptosis. Los estudios efectuados con el ODN de control no mostraron ninguna de las características descritas. Conclusión: La incubación de ODN con motivos PyNTTTTGT (IMT504) y con motivos CpG (2006) induce en las células de LLC-B un fenotipo considerado de células presentadoras de antígenos, y además apoptosis. Perspectiva: En otros estudios preclínicos y clínicos los ODNs han demostrado muy baja toxicidad, lo que permitiria efectuar estudios de Fase I/II en LLC-B

Laparoscopic management of Meckel's diverticulum in adults.

BACKGROUND: Meckel's diverticulum is an uncommon entity. A high index of suspicion is necessary for opportune diagnosis and prompt treatment. Technetium (TC) 99m pertechnetate scintigraphy is a sensitive and specific test for Meckel's diverticulum. In adults, the scan contributes little to clinical decision making and often will not change the need for surgical intervention. We describe our experience with four patients. METHODS: Between August 2000 and August 2001, four patients were seen with Meckel's diverticula. Three were male and one was female. The mean age was 39 years (range, 18-64). Three patients presented with anemia and one with an acute abdomen. A 99mTc pertechnetate scan was performed at a cost of 900 dollars in the three anemic patients after other endoscopic and radiographic tests were nondiagnostic. Only one patient had a positive scan. All four patients underwent exploratory laparoscopy and small bowel resection. In one patient, a minilaparatomy had to be performed. RESULTS: All patients had a satisfactory outcome without complications. Three patients were discharged within 3 days of surgery. The remaining patient had a prolonged hospital stay because of ongoing chemotherapy for small cell lung cancer. In the three anemic patients who underwent enterectomy, ulcerated small bowel outside the diverticulum was found by the pathologist. CONCLUSION: Laparoscopy is safe, cost-effective, and efficient for the diagnosis and definitive management of Meckel's diverticulum. Technetium 99m pertechnetate scintigraphy scanning adds considerable time and expense to the care of the patient without significant benefits in adults. The practice of exploratory laparoscopy rather than scintigraphy is recommended.

Totally laparoscopic management of gallstone ileus.

Gallstone ileus is an uncommon disease of elderly patients who present with bowel obstruction. Mortality and severe complications are common, even in modern series, due to the comorbidities in the affected patient population. A number of less invasive ways to treat this disease are described. We report on a case where enterolithotomy was performed laparoscopically. The patient is a 60-year-old diabetic woman who presented with a bowel obstruction and pneumobilia on abdominal radiographs. She underwent exploratory laparoscopy using three reusable ports, an enterolithotomy, and her remaining bowel was examined. The benefits to a minimal access approach to this rare disorder are discussed. The ability to suture laparoscopically is emphasized.

Laparoscopic choledochojejunostomy and gastrojejunostomy in a porcine model.

BACKGROUND: Surgical extirpation remains the only known curative treatment for cancer of the pancreas. Because of locally advanced or metastatic tumor, up to 80% of patients are unresectable at the time of initial diagnosis [13]. Other investigators previously have suggested that laparoscopy before laparotomy aids in the diagnosis of unresectable pancreatic cancer in a fair number of patients even after negative computed tomography scans [3, 17]. Many surgeons are reluctant to incorporate laparoscopy into the workup of patients with cancer of the pancreas because of the frequent need for surgical bypass in the management of either biliary tract obstruction or gastric outlet obstruction [9, 13]. Previous studies have demonstrated the feasibility of laparoscopic cholecystojejunostomy combined with gastrojejunostomy in a porcine model, as well as the individual accomplishment of laparoscopic choledochojejunostomy. The purpose of this study was to document the feasibility of performing laparoscopic choledochojejunostomy with gastrojejunostomy. METHODS: Under general anesthesia, seven pigs underwent laparoscopic choledochojejunostomy and gastrojejunostomy using an intracorporeal hand-sutured technique. RESULTS: The mean operating time ranged from 150 to 450 min. All the animals recovered completely from the operation and had patent anastomoses at the time of necropsy. One pig died of gastric bleeding on postoperative day 13, and two animals had intraabdominal fluid collections discovered at the time of necropsy. CONCLUSIONS: These results suggest that synchronous laparoscopic bypass of biliary and gastric outlet obstruction is feasible, and can be performed in a manner similar to that used in open operations. We believe this lends support to the argument promoting laparoscopy in the evaluation of pancreatic cancer.

Totally laparoscopic feeding jejunostomy.

BACKGROUND: A feeding jejunostomy should be used for nutritional support in a small subset of patients. Minimal-access approaches for the placement of jejunal tubes have been described, but they often require special equipment not common to all operating theaters. We describe a technique of totally laparoscopic jejunostomy tube (LJT) placement using equipment found in most operating theaters. METHODS: Thirty-five patients underwent LJT over a 12-month period. Indications included gastroparesis, anorexia nervosa, oral cancer, cerebral palsy, and Huntington's chorea. The technique involved three incisions for trocars (one for a 10-mm camera and two for 5-mm working ports) and one small incision for the tube. A 16-Fr T-tube was passed transabdominally under direct vision, and a jejunotomy was made approximately 20 cm distal to the ligament of Trietz. Each limb of the T-tube was passed into the lumen of the bowel, and a purse-string suture was placed around the enterotomy and tied intracorporeally. After insertion, the serosa surrounding the insertion site is tacked to the anterior abdominal wall in four places with a reusable stainless steel suture passer. To test whether the tube was watertight, we injected methylene blue solution into the tube. RESULTS: All of the patients tolerated the procedure well. There were no operative deaths. Five LJTs were electively removed in the office. One patient was reoperated on 10 days postoperatively because of intractable pain, but the source of pain was not found and the LJT was intact. CONCLUSIONS: LJT may be placed safely using the described technique. No significant morbidity or mortality occurred in our series. The results of this study have prompted us to consider LJT for any patient requiring access to the jejunum for feeding.

Laparoscopic autopsies.

BACKGROUND: In recent years, autopsy consent rates have fallen nationwide. In our institution they have declined from 15% to 7% in 10 years. We perceived that family reluctance to grant permission for autopsy was related to the invasiveness of the open procedure, so we began to do autopsies by needle biopsy, with an increase in consents to 25% during the first year. However, the procedure is inherently inaccurate, so we recently have introduced minimally invasive laparoscopic autopsy. METHODS: From July through October 1999, needle biopsy was performed on 25 patients who died at our institution, which was followed by laparoscopic evaluation. Consent for full conventional autopsy had been granted in nine cases, and these then were performed. Data from these autopsies were compared with those from the laparoscopic procedures. RESULTS: Of the patients for whom consent was obtained for open autopsy, there was complete agreement as to cause of death between the laparoscopic and conventional procedures. In one case, a liver hemangioma was missed by laparoscopy, and in two other cases, colon polyps were not discovered. Biopsies of internal organs were accurately performed on the pancreas, kidneys, and adrenals, all of which had been troublesome for needle biopsy alone. CONCLUSIONS: Laparoscopic autopsy is much more acceptable to the families of patients than the conventional form, resulting in a higher consent rate. On the basis of our study group, this procedure provides accurate data concerning the cause of death. In addition, performing these autopsies gives surgical residents invaluable training in laparoscopic skills.

The routine use of diagnostic laparoscopy in the intensive care unit.

BACKGROUND: Delay in the diagnosis of intraabdominal pathology is a major contributor to the morbidity and mortality of intensive care unit (ICU) patients. Laparoscopy is a valuable diagnostic tool that can be used safely and efficiently in the evaluation of intraabdominal processes that may be difficult to diagnose with conventional methods. Our goal was to show that laparoscopy performed at the bedside in the ICU could be used as a routine diagnostic tool in the evaluation of critically ill patients, just as computed tomography (CT), ultrasonography (US), and radiography are. METHODS: We present 11 patients who underwent 12 bedside examinations in the ICU of a community teaching hospital. Several different surgeons with varying degrees of laparoscopic experience performed these procedures over a 1-year period. RESULTS: Four patients had previously undergone recent abdominal operations. Nontherapeutic laparotomy was avoided in six patients because of diagnostic laparoscopy. One patient also underwent a therapeutic maneuver at the time of diagnostic laparoscopy. None of the patients required general anesthesia, although local anesthetics and sedation with midazolam or propofol were used. One patient underwent the procedure without endotracheal intubation. There were no complications or mortalities directly related to the procedure. CONCLUSION: We conclude that bedside laparoscopy in the ICU under local anesthesia is a diagnostic and potentially therapeutic tool that can be used safely in the work-up of potential abdominal pathology in critically ill patients.

Laparoscopic distal pancreatectomy for blunt injury to the pancreas. A case report.

Laparoscopic pancreatic resection has not been reported for traumatic injuries to the pancreas. We present the case of a laparoscopic distal pancreatectomy performed on a 10-year-old boy after he sustained a distal transection of the pancreas due to blunt abdominal trauma. The spleen and its vessels were preserved. The patient was sent home on postoperative day 3 without any postoperative complications. Performing an advanced laparoscopic pancreatic procedure is feasible, in the trauma setting, particularly in children.

Incidence of incipient contralateral hernia during laparoscopic hernia repair.

BACKGROUND: In addition to its well-known benefits of decreased postoperative pain and shorter recovery time, laparoscopic hernia repair has the major advantage of allowing the surgeon to explore the side contralateral to the clinically diagnosed hernia. The purpose of this study was to evaluate the incidence of incipient unsuspected contralateral hernia during totally extraperitoneal (TEP) laparoscopic inguinal herniorrhaphy and to analyze the risks and benefits of identifying these hernias at the time of the initial surgery. METHODS: We did a retrospective review of the charts of all of the 724 male patients who underwent laparoscopic TEP repair of 958 groin hernias between September 1991 and September 1999. The initial clinical impression of the existence of unilateral or bilateral hernias was noted and compared to our operative findings. The same surgeon performed all the repairs. Exploration of the contralateral side was performed in a systematic fashion. A second mesh prosthesis was placed if a contralateral hernia was found. RESULTS: Bilateral hernia repair was performed on 234 patients (32. 3%). In 62 of them (11.2%), the contralateral hernia was diagnosed only at the time of the procedure. Operative time ranged from 14 to 185 min (median, 38.6). The operative time for the contralateral exploration ranged from 2 to 5 min (median, 2.8). The rate of complications was 4.1%, but no complications were directly related to the exploration of the asymptomatic side. CONCLUSION: Our study shows that a large number of inguinal hernias are undiagnosed by physical examination (11.2%). Systematic contralateral exploration using the TEP approach is safe and does not greatly increase the operative time. Early identification and repair of a contralateral hernia obviates the need for reoperation, reduces overall costs to the health care system, and eliminates any further work loss for the patient.

Combination salvage chemotherapy with MIZE (ifosfamide-mesna, idarubicin and etoposide) for relapsing or refractory lymphoma.

In this study, 54 patients with relapsed or refractory non-Hodgkin's lymphoma (NHL) were treated in a phase II, multicentric trial with ifosfamide-mesna 1500 mg/m2 IV days 1-3, idarubicin 12 mg/m2 IV day 1 and etoposide 100 mg/m2 IV day 1-3 (MIZE). Overall response was 72%; complete response (CR) and partial response (PR) were 46% and 26% respectively. In Stage I-II pts CR was 59% and in Stage III-IV pts CR was 40.5%. Patients who relapsed from an initial CR had a 64% CR rate when treated with MIZE, in contrast to refractory disease's patients who only had 19% CR (p = 0.004). The group of pts that had an objective response (CR + PR) to front line therapy had a 2 year survival rate of 55% compared with none for refractory disease (p = 0.029) after salvage therapy. Median survival for the entire group was 17.5 months. Better survival was seen in pts who were asymptomatic with low levels of LDH, previous CR, non high-grade histology, and limited disease stage at relapse. Toxicity was mainly hematologic: 91.5% had neutropenia, (56.5% grade III-IV), and 9.5% died from infectious complications. Other clinical toxicities including cardiac toxicity were negligible. MIZE chemotherapy was effective in patients with relapsed and refractory lymphoma and showed limited clinical and cardiac toxicity. Myelosupression was the most frequent single toxicity.

Regulation of apoptosis in thymocytes.

Programmed cell death, or apoptosis, is tightly regulated during the development of T lymphocytes. Several studies have indicated that in normal mice, thymocyte are sensitive to apoptosis primarily during a brief period relatively late in the CD4+8+ maturation stage, when both positive and negative selection are thought to occur. One factor regulating sensitivity to apoptosis may be the expression and signalling capacity of the TcR/CD3 complex on developing thymocytes. In the present study, we report that sensitivity to apoptosis in immature thymocytes may also be regulated by a mechanism that can prevent induction of apoptosis in many thymocytes. This protective mechanism is induced by TcR/CD3 engagement and cross-linking, as well as by agents that mimic TcR/CD3-dependent phosphoinositol bisphosphate hydrolysis and activate Ca++ fluxes and Protein Kinase C. Cyclosporin A (CsA) inhibits the protective mechanism, permitting the induction of apoptosis by TcR/CD3 or TcR/CD3-mimicking stimuli in otherwise resistant thymocytes. In contrast, mature naive T cells do not undergo apoptosis following stimulation by these agents, even in the presence of CsA, suggesting that in mature naive T-cells the apoptotic machinery itself is normally no longer inducible. We discuss the possible implications of these results for regulation of T-cell development. In this study we also demonstrate that CsA can inhibit the ability of accessory cells to trigger thymocyte apoptosis in accessory cell-dependent assays, which may explain previous reports that CsA can inhibit the induction of thymic clonal deletion in vivo.

The effects of immunosuppressive drugs on the regulation of activation-induced apoptotic cell death in thymocytes.

This study investigated the effects of immunosuppressive drugs on the regulation of thymocyte sensitivity to clonal deletion via programmed cell death, or apoptosis. We have previously shown that TcR/CD3 cross-linking and intracellular stimuli that mimic TcR/CD3 cross-linking induce apoptosis in many immature thymocytes in the presence, but not in the absence, of cyclosporine (CsA). We have interpreted those results to suggest that TcR/CD3-associated signals induce a CsA-sensitive mechanism that protects the cells from activation-induced apoptosis. In the present study, we compared the effects of CsA, FK506, and rapamycin (RAP) on the regulation of thymocyte apoptosis. Optimal concentrations of CsA and FK506 augmented apoptosis to similar levels. However, FK506 was approximately 100-fold more potent than CsA in thymocytes, which parallels the relative potencies of these drugs in inhibiting mitogen-induced proliferation of mature T cells. In contrast to CsA and FK506, RAP did not exhibit substantial apoptosis-augmenting activity. However, RAP interfered with the activity of FK506. This pattern mirrors that of RAP in TcR/CD3-mediated signaling pathways in mature T cells. Together these results provide evidence (1) that CsA, FK506, and RAP can act on immature thymocytes, (2) that the mechanisms by which the drugs affect mature and immature T cell responses are similar, and (3) that immunosuppressive drug therapy may affect not only mature peripheral T cells but also developing immature thymic T cells.

Synergistic actions of PAF-acether and sodium arachidonate in human platelet aggregation. 1. Studies in normal human platelet rich plasma.

The effect of sodium arachidonate and paf-acether in the activation of human platelet was studied. Concentrations of paf-acether which induced a reversible aggregation in normal human platelet rich plasma (0.029-0.0029 microM) and subthreshold concentrations of sodium arachidonate (0.25-0.35 mM), produced full aggregation when added together. Pre-exposition of platelets to paf-acether that renders them insensitive to paf-acether supresed the synergism. With full aggregation a markedly increase of thromboxane synthesis was detected by RIA. In vitro addition of aspirin (200 micrograms/ml) or indomethacin (12 microM) prevented aggregation and thromboxane formation by the joint action of sodium arachidonate plus paf-acether. Specific inhibition of 12-lipoxygenase by esculetin (10 microM) did not affect the synergistic action of paf-ace-ther and sodium arachidonate. These findings suggest that synergism between both agonists is mediated by active derivatives of arachidonic acid via cyclooxygenase.

Erythrokinetic studies in myelofibrosis: their significance for prognosis.

Eighty-three patients with myelofibrosis have been studied by erythrokinetics and have been followed up until death or for at least 12 months. Because of a large plasma volume the venous haematocrit gives only a poor idea of the red blood cell volume. The red cell survival was reduced in the majority of cases but significant haemolysis was rare. The amount of haemolysis of autologous and isologous red cells was similar, suggesting an extra-corpuscular origin for the haemolysis. Plasma iron turnover was always increased, sometimes markedly, but red cell iron incorporation was reduced in 70% of cases, indicating ineffective erythropoiesis. Surface counting showed an absence on diminution of sacral iron fixation and a rapid and marked splenic uptake in more than 90% of the cases; uptake of iron by the liver occurred in half the cases, usually not very high; iron release from the spleen was absent or reduced in 67% of the cases. The degree of ineffective erythropoiesis as measured by radio-iron incorporation and release by the spleen, the amount of haemolysis, and the red cell volume were strongly correlated with prognosis. These factors enabled a more precise prediction to be made of the clinical outcome in the 2 years following the study, than the clinical data alone. A prospective study might show whether erythrokinetic studies are also useful in determining the choice of treatment.