Rapid coupling between ice volume and polar temperature over the past 150,000 years.

Current global warming necessitates a detailed understanding of the relationships between climate and global ice volume. Highly resolved and continuous sea-level records are essential for quantifying ice-volume changes. However, an unbiased study of the timing of past ice-volume changes, relative to polar climate change, has so far been impossible because available sea-level records either were dated by using orbital tuning or ice-core timescales, or were discontinuous in time. Here we present an independent dating of a continuous, high-resolution sea-level record in millennial-scale detail throughout the past 150,000 years. We find that the timing of ice-volume fluctuations agrees well with that of variations in Antarctic climate and especially Greenland climate. Amplitudes of ice-volume fluctuations more closely match Antarctic (rather than Greenland) climate changes. Polar climate and ice-volume changes, and their rates of change, are found to covary within centennial response times. Finally, rates of sea-level rise reached at least 1.2 m per century during all major episodes of ice-volume reduction.

Laparoscopic colectomy for transverse colon carcinoma.

BACKGROUND: Laparoscopic resection of transverse colon carcinoma is technically demanding and was excluded from most of the large trials of laparoscopic colectomy. The aim of this study was to assess the safety, feasibility, and outcome of laparoscopic resection of carcinoma of the transverse colon. METHODS: A retrospective review was performed to identify patients who underwent laparoscopic resection of transverse colon carcinoma. These patients were compared to patients who had laparoscopic resection for right and sigmoid colon carcinoma. In addition, they were compared to a historical series of patients who underwent open resection for transverse colon cancer. RESULTS: A total of 22 patients underwent laparoscopic resection for transverse colon carcinoma. Sixty-eight patients operated for right colon cancer and 64 operated for sigmoid colon cancer served as comparison groups. Twenty-four patients were identified for the historical open group. Intraoperative complications occurred in 4.5% of patients with transverse colon cancer compared to 5.9% (P = 1.0) and 7.8% (P = 1.0) of patients with right and sigmoid colon cancer, respectively. The early postoperative complication rate was 45, 50 (P = 1.0), and 37.5% (P = 0.22) in the three groups, respectively. Conversion was required in 1 (5%) patient in the laparoscopic transverse colon group. The conversion rate and late complications were not significantly different in the three groups. There was no significant difference in the number of lymph nodes harvested in the laparoscopic and open groups. Operative time was significantly longer in the laparoscopic transverse colectomy group when compared to all other groups (P = 0.001, 0.008, and <0.001 compared to right, sigmoid, and open transverse colectomy, respectively). CONCLUSIONS: The results of laparoscopic colon resection for transverse colon carcinoma are comparable to the results of laparoscopic resection of right or sigmoid colon cancer and open resection of transverse colon carcinoma. These results suggest that laparoscopic resection of transverse colon carcinoma is safe and feasible.

Stable high-order molecular sandwiches: hydrocarbon polyanion pairs with multiple lithium ions inside and out.

Stable ten-component sandwich compounds have been characterized in which four lithium ions reside between two tetraanions derived from corannulene or its alkyl-substituted derivatives and four additional lithium ions decorate the exterior. In tetrahydrofuran solution, the four lithium ions inside the sandwich can exchange environments with the four external lithium atoms, but the two tetraanion decks of the sandwich never separate from one another on the time scale of nuclear magnetic resonance. Theoretical calculations point to a "stacked bowl" conformation and a low energy barrier for synchronous double inversion of the tetraanion bowls in the solvated sandwich compounds.

Acetylcholinesterase and butyrylcholinesterase genes coamplify in primary ovarian carcinomas.

The genes for acetylcholinesterase (ACHE) and butyrylcholinesterase (CHE) are expressed in multiple tumor tissues, including ovarian carcinomas. Both CHE and ACHE genes coamplify in leukemias. To examine the relationship of gene amplification to the expression of these genes in tumors, ACHE and CHE genes and their expression were studied in primary ovarian carcinomas. DNA blot hybridization demonstrated a significant amplification and mutagenesis of both genes in 6 of 11 malignant tumors studied. This was greater or of the same order of magnitude as the amplification of the oncogenes c-rafi, v-sis, and c-fes in these tumors. No amplification was found in normal ovarian tissues or benign ovarian cysts. Xenopus oocyte microinjections, blot and in situ hybridizations, and immuno- and cytochemical staining revealed translatable CHEmRNA and its active protein product in discrete tumor foci. The frequent coamplification in ovarian carcinomas of ACHE and CHE genes implicates cholinesterases in neoplastic growth and/or proliferation.

Laparoscopically assisted reversal of Hartmann's procedure.

BACKGROUND: Restoration of bowel continuity after Hartmann's procedure is a major surgical procedure associated with substantial morbidity and occasional mortality. The authors review their experience with laparoscopically assisted reversal of Hartmann's procedure (LARH) to assess difficulties and potential advantages associated with this procedure. METHODS: A retrospective chart review of a prospectively entered database was performed to identify patients who underwent LARH over a period of 7 years. Data regarding demographic and clinical characteristics, surgical details, and postoperative course were reviewed. Specifically, age, gender, diagnosis at initial operation, American Society of Anesthesiology (ASA) score, comorbidities, operative time, conversion, surgical team, complications, postoperative bowel movements, and hospital stay were assessed. All surgeries were performed by six experienced laparoscopic surgeons. RESULTS: A total of 27 patients, 17 men and 10 women, with mean ages of 58.1 and 62.9 years, respectively, underwent LARH. The procedure was laparoscopically completed for 23 patients. Conversion to laparotomy was required for four patients (14.8%) because of dense adhesions after the initial Hartmann's procedure in three patients and rectal perforation in one patient. The median operative time was 226 min, and the median hospital stay was 6 days. The overall morbidity rate was 33% (9 patients), attributable to colostomy site infection in 5 of the 9 patients. One patient required reoperation because of intraabdominal bleeding. No anastomotic leaks or intraabdominal abscesses were recorded. There was no operative mortality. CONCLUSIONS: Laparoscopically assisted reversal of Hartmann's procedure is technically challenging and time consuming. However, in the hands of experienced laparoscopic surgeons, it is safe and associated with a reasonably low conversion rate. Furthermore, the relatively low morbidity rate, short hospital stay, and earlier return of bowel function may be beneficial to patients.

Splenic artery aneurysms in liver transplant patients.

We found splenic artery aneurysms in 6 of 71 consecutive patients who underwent orthotopic liver transplantation at the Mayo Clinic. The incidence of splenic artery aneurysms in cirrhotic patients with portal hypertension was 10%. Five of the aneurysms were found in patients suffering from chronic active hepatitis, whereas no aneurysms were encountered in patients with primary sclerosing cholangitis or primary biliary cirrhosis. One patient ruptured a splenic artery aneurysm shortly after liver transplantation, and 1 patient developed an aneurysm 3 months after transplantation. We recommend coeliac angiography to be performed prior to liver transplantation, and if splenic artery aneurysms are found, ligation of the splenic artery should be performed at the time of transplantation to prevent possible rupture.

The use of radioiodinated toluidine blue for preoperative localization of parathyroid pathology.

The efficiency of preoperative radioactive toluidine blue (RTB) scintigraphy for the localization of parathyroid pathology was evaluated prospectively in 69 patients (age range, 15 to 81 years; mean, 56 years) with primary hyperparathyroidism. Four patients have previously undergone negative exploratory surgery. Patients underwent preoperative dual radionuclide parathyroid-RTB/technetium 99m (Tc 99m)-thyroid scintigraphies with a computer-interfaced gamma-camera with a pinhole collimator. Computer-acquired scintigraphic data were analyzed for parathyroid localizations by an RTB-parathyroid/thyroid superposition technique. At surgery, parathyroid adenomas were found in 64 patients (single adenomas in 60 patients; two adenomas in four patients), nine of these adenomas were mediastinal. Four patients had parathyroid hyperplasia. One patient had no parathyroid pathology (negative exploratory surgery). Correlation between the surgical-pathologic findings and the scintigraphic RTB localization studies disclosed a sensitivity of 87%, with a specificity of 94%, and an overall accuracy of 92%. The routine use of preoperative scintigraphic parathyroid-RTB/Tc 99m-thyroid localization has proved to be highly effective, enabling detection of small hyperfunctioning parathyroid glands in normal and ectopic locations in a wide range of weights. In this series a success rate of 98% was achieved on initial and reexploratory surgery for primary hyperparathyroidism.

The role of circulating N-terminal parathyroid hormone fragments in the early postparathyroid adenomectomy period.

Calcium metabolism and hormonal control after parathyroid adenomectomy are poorly understood. During the first postoperative hours, biologically active intact parathyroid hormone (PTH) (hPTH 1-84) levels are subnormal and, in spite of down-regulation of PTH peripheral receptors (caused by hypercalcemia before surgery), total and ionized calcium concentrations are maintained in the normal range. Serum samples from 20 patients with primary hyperparathyroidism were collected in the immediate preoperative period and 4 and 48 hours after excision of one parathyroid adenoma. Total and ionized calcium, intact (iPTH), midregion (mrPTH) specific PTH (hPTH 53-68), and N-terminal PTH (N-PTH) serum concentrations were determined. Levels of N-PTH were obtained with a radioimmunoassay by a modified reverse immunoextraction procedure that measures N-PTH fragments after exclusion of the interfering iPTH. No significant correlation was found between ionized and total calcium, mrPTH, and iPTH. However, total and ionized calcium levels correlated well with N-PTH (r = 0.9999, p = 0.0054, and r = 0.9993, and p = 0.0226, respectively). The data suggest that the relatively moderate decrease in calcium levels, in spite of marked decrease in circulating iPTH during the first postoperative hours, may be attributable to the minimal decrease of the bioactive N-PTH epitope concentrations. We would hypothesize that hPTH (1-34) fragments may play a significant role in regulating serum calcium levels in the early postoperative period.

Release of antral gastrin in response to an intestinal meal in dogs.

This study was designed to determine whether gastrin is released by the antrum in response to an intestinal meal in dogs. Two groups of anesthetized dogs were prepared with innervated antral pouches. The antrum and duodenum were separated by complete division at the pylorus to prevent duodenoantral reflux. The duodenum and proximal jejunum were perfused with 10% liver extract at 200 ml/hr. In one group of six dogs a significant elevation of antral vein gastrin levels was observed after 45 minutes. Gastrin levels in portal and peripheral blood were not significantly elevated. In another group of eight dogs, in which antral veins were not cannulated, a significant rise in peripheral gastrin concentration was noted after 60 minutes. We conclude that gastrin is released by the antrum during the intestinal phase of gastric acid secretion; significantly increased levels of gastrin are detected in both antral and peripheral venous blood. Duodenoantral reflux, as a possible cause of this release, is ruled out by complete surgical separation between duodenum and antrum.

Correct preoperative localization: does it permit a change in operative strategy for primary hyperparathyroidism?

BACKGROUND: A meticulous bilateral neck exploration by an experienced endocrine surgeon offers a high cure rate with low morbidity for patients with primary hyperparathyroidism. The advent of localizing studies raises the possibility of unilateral neck exploration. The cost-effectiveness of preoperative localizing studies and unilateral neck exploration in primary hyperparathyroidism are controversial issues. This study was designed to determine the risks of missing a contralateral pathologic parathyroid gland in patients with preoperative localization that was confirmed at neck exploration. METHODS: Preoperative studies (ultrasonography, nuclear radioactive imaging scan, or both) were performed in 79 patients with primary hyperparathyroidism. In 58 patients a definite localization of an enlarged parathyroid gland was confirmed at operation. All patients underwent a meticulous bilateral neck exploration. RESULTS: Unilateral neck exploration was feasible only in 73.4% of the patients, according to our localizing modalities, and an additional enlarged parathyroid gland on the contralateral side, not detected before operation, was revealed in five patients (8.6%). False-positive rates were 1.7% for ultrasonography and 13% for scan. CONCLUSIONS: These results indicate an unacceptably high surgical failure rate for unilateral neck exploration guided by preoperative localizing studies compared with a bilateral neck exploration by an experienced endocrine surgeon, questioning the cost-effectiveness of preoperative localizing studies.

Ureterocele--a familial congenital anomaly.

Nonidentical twins with ectopic ureteroceles, and duplication of the urinary collecting system in two more members of the same family are described. This incidence may indicate that inborn anomalies of the urinary tract may have a genetic background.

Surgical aspects of gastrointestinal persimmon phytobezoar treatment.

One hundred thirteen patients presented with gastrointestinal complications due to persimmon phytobezoars during a 3 year period. One hundred three patients had a history of persimmon ingestion. One hundred five patients had undergone previous gastric operation for duodenal ulcer, one patient underwent highly selective vagotomy, and seven patients had not undergone previous operation. An elevated temperature, leukocytosis, and decreased bowel sounds were typical early clinical manifestations of small bowel obstruction by persimmon phytobezoars. In 13 patients, gastric bezoars were found, in 20 patients, gastric and intestinal bezoars, and in 80 patients, intestinal bezoars. One hundred patients were treated surgically. In 14 of the 20 patients with concomitant gastric and intestinal phytobezoars, extraction of the bezoars was achieved by gastrotomy. Of the remaining six patients, it was achieved by intraoperative milking of the gastric bezoar into the small bowel in two patients and by conservative treatment in four patients. Of the 100 patients who presented with small bowel obstruction, 60 were treated by milking of the bezoar into the large bowel, 34 by enterotomy, and 6 by conservative therapy with intravenous fluids, gastric suction, and a water-soluble contrast meal. Small bowel resection of a gangrenous segment was necessary in two patients. Two patients died after operation because of sepsis and respiratory complications. Eleven of the 13 patients in whom postoperative wound infection developed underwent gastrotomy or enterotomy. We conclude that the treatment of choice of intestinal obstruction due to persimmon phytobezoars is milking of the bezoar into the large bowel without enterotomy. Preoperative or operative endoscopy should be performed in patients presenting with complications of gastrointestinal phytobezoars. Patients who have undergone gastric operation should be warned against the risk of persimmon ingestion.

Does luminal gastrin stimulate gastric acid secretion?

The effects of pentagastrin on acid secretion, short circuit current, electrical conductance and potential difference were determined in isolated bullfrog fundic mucosa. Biologically active luminal pentagastrin had no effect on gastric mucosa, even at a concentration 100 times higher than that necessary for stimulation of the mucosa from the serosal side. It is concluded that luminal gastrin does not appear to have a physiologic role in gastric secretory processes.

Osteomyelitis of the clavicle after subclavian vein catheterization.

Osteomyelitis of the clavicle or the sternoclavicular joint is a rare complication of subclavian vein catheterization. Soft tissue infections around the puncture site occur frequently and respond well to topical and antibiotic treatment. If symptoms persist for several weeks, osteomyelitis or sternoclavicular pyo-arthrosis should be considered. Bone and gallium scintigraphy scans and computerized tomography scans are helpful diagnostic measures.

Laparoscopic transabdominal suspension sutures.

A limited number of access ports used in laparoscopic surgery may impair the ability of the surgeon to achieve adequate retraction and exposure, or to stabilize "moving targets" while operating on nonfixed organs. Solutions such as adding more ports or using a hand-assisted technique have the disadvantages of being more invasive, possibly creating a cumbersome situation of multiple instruments in a limited working space. We describe a useful technique for retraction and stabilization with the use of temporary sutures that pass through the abdominal wall. Although not new, this technique is not widely known or used, and laparoscopic surgeons may find it useful for a variety of applications.

Laparoscopic management of surgical complications after a recent laparotomy.

BACKGROUND: The use of laparoscopy in the scarred abdomen is now well established. However, recent laparotomy and the presence of a fresh abdominal wound usually preclude laparoscopic intervention. Thus, early postlaparotomy complications, which mandate surgical interventions, are usually treated by a second laparotomy. We report our experience with the use of laparoscopy for the treatment of postoperative complications, after open abdominal procedures. METHODS: Fourteen patients were operated for a variety of conditions, and postoperative complications, such as bowel obstruction, intraabdominal infection, or anastomotic insufficiency, were handled laparoscopically. RESULTS: Eleven patients recovered from the acute condition. One patient died from sepsis, one retroperitoneal abscess was missed and later drained percutaneously, and one conversion to open surgery was necessary because of adhesions and lack of working space. CONCLUSIONS: We conclude that a recent laparotomy is not a contraindication for laparoscopic management of acute abdominal conditions. Postlaparotomy complications can be successfully treated by laparoscopy. Avoiding the reopening of the abdominal wound and a second laparotomy may reduce the additional surgical trauma, and thus result in easier recovery.

Preperitoneal bupivacaine attenuates pain following laparoscopic inguinal hernia repair.

BACKGROUND: Laparoscopic preperitoneal inguinal hernia repair is associated with a short hospital stay and an early return to normal activity. Therefore, early postoperative pain control is important. The aim of this study was to evaluate the effect of preperitoneal Bupivacaine instilled into the preperitoneal cavity on pain following laparoscopic mesh repair of inguinal hernia. METHODS: After institutional review board approval, 44 patients undergoing elective laparoscopic inguinal hernia repair were prospectively randomized into two groups. Upon completion of the Prolene mesh repair, group A received 80 mg of Bupivacaine in 25 cc of saline installed into the preperitoneal space, whereas group B received normal saline installed into the preperitoneal space. Pain was assessed using a visual analog scale at fixed time intervals; the amount of analgesics required was also recorded. RESULTS: Twenty-two patients were included in each group. The demographic characteristics and type of surgery (unilateral vs bilateral) did not significantly differ between the two groups. The average pain levels were significantly attenuated in group A compared to group B at 1 (4.0 vs 5.0, respectively; p = 0.0038), 2 (4.0 vs 5.9, respectively; p = 0.0015), and 4 (4.3 vs 5.8, respectively; p = 0.0038) h after surgery. Furthermore, the analgesic intake was significantly decreased in group A compared to group B. CONCLUSION: Preperitoneal Bupivacaine attenuates pain following laparoscopic inguinal hernia repair and should be considered in these cases.

Laparoscopic distal pancreatectomy.

BACKGROUND: Advanced laparoscopic techniques have been adapted to various surgical pathologies, including pancreatic tumors, with the potential benefits of attenuated surgical trauma, faster recovery, and improved cosmesis. Laparoscopic pancreatic surgery is technically demanding, and thus has not yet gained widespread acceptance. The aim of this study was to review our preliminary experience with laparoscopic distal pancreatectomy for benign and malignant pancreatic pathologies. METHODS: A retrospective chart review of consecutive patients with benign and malignant pancreatic tumors who underwent laparoscopic distal pancreatectomy in a university-affiliated department of surgery between 1997 and 2003 was performed. Data relative to demographic and clinical characteristics, indications for surgery, surgical procedure, and postoperative course were recorded. RESULTS: Laparoscopic distal pancreatectomy was attempted for 12 patients with benign (n = 8) and malignant (n = 4) pancreatic tumors and successfully completed laparoscopically in 75%, of these cases. Six early postoperative complications (two abscesses, two instances of diabetes mellitus, two pancreatic leaks) developed in three patients. The spleen was successfully preserved in 58% of the cases. CONCLUSIONS: This preliminary experience suggests that laparoscopic distal pancreatectomy is a feasible and safe procedure with a morbidity rate comparable with that for the conventional open procedure. However, laparoscopic surgery for malignant pancreatic tumors remains controversial. Larger series with longer follow-up periods are necessary to determine the role of laparoscopic surgery in the treatment of pancreatic pathologies.

Pitfalls and complications with laparoscopic intraperitoneal expanded polytetrafluoroethylene patch repair of postoperative ventral hernia.

BACKGROUND: This study reviewed our experience with laparoscopic ventral postoperative (incisional) hernia repair. METHODS: Clinical data from the first 100 cases were analyzed retrospectively. RESULTS: Between 1997 and 2000, 64 women and 36 men (mean age, 58.4 +/- 13.6 years; range, 27-87 years) underwent laparoscopic hernioplasty. Hernias (mean diameter, 6.2 +/- 3.7 cm) were in a midline (74%), subcostal (10%), or other incision location, and were recurrent in 25%, of the patients. The mean operative time was 119 +/- 77 min. Extensive adhesiolysis was necessary in 37 cases. There was no mortality. The recorded complications included inadvertent enterotomies (n = 6), seromas (n = 11), prolonged ileus (n = 4), and prolonged fever (n = 3). Seven cases were converted; to repair accidental enterotomies (n = 4) due to difficult adhesiolysis (n = 2), or to control bleeding (n = 1). Six patients underwent reoperation because of enetric leak (n = 3) or bowel obstruction (n = 3). There were two documented recurrences (2%). The mean follow-up period was 19 months (range, 12-54 months). CONCLUSIONS: Laparoscopic intraperitoneal approach to postoperative ventral (incisional) hernia repair may be associated with significant complications and morbidity, which can be prevented in part by meticulous technique and liberal conversions. The justification of this procedure is the low recurrence rate, according to preliminary results.

140 consecutive cases of minimally invasive, radio-guided parathyroidectomy: lessons learned and long-term results.

BACKGROUND: The advent of highly accurate parathyroid imaging and the ever-increasing trend towards minimally invasive procedures have changed considerably the surgical approach to the patient with primary hyperparathyroidism (PHPT) caused by a single parathyroid adenoma. This study analyzes the short- and longer-term results of 140 patients who underwent minimally invasive, radio-guided parathyroidectomy. METHODS: Demographic, clinical, and pre-operative imaging data, operative findings, and short- and long-term results of 140 consecutive patients operated within a 20 months period (8/1999-4/2002), were prospectively entered into a database. Immediate pre-operative sestamibi scintigraphy with skin marking of focal adenoma uptake were followed by intraoperative hand-held gamma probe for the removal of the parathyroid adenoma by unilateral minimal access surgery. Preoperative and surgical data were analyzed and correlated to outcomes, measured by success or failure to cure PHPT, associated morbidity and mortality, predictive value of localizing studies, and postoperative laboratory results in the immediate as well as long-term period. RESULTS: 140 patients, mean age: 55.1 +/- 14.1 years (range 19-88 years), female to male ratio 94:46 with PHPT proven by concomitantly elevated serum calcium and parathormone (PTH) levels, with a single adenoma identified by sestamibi single photon emission tomography (SPECT) scintigraphy and high-resolution sonography, underwent minimally invasive, radio-guided parathyroidectomy. Mean serum levels of preoperative calcium, phosphorus, and PTH were 11.6 +/- 0.8 mg/dL (range 9.1-14), 3.0 +/- 0.3 mg/dL, and 147.1 +/- 94.3 pg/mL (range 68-784), respectively. Overall, in 3 out of 140 patients (2.1%), focused, minimally invasive surgery failed to identify and remove the adenoma. Positive predictive value when both localizing modalities concurred was 99.2%. Positive predictive value of SPECT scan alone was 97.2%. Overall success rate was 97.8% (137/140). 24 hours postoperative mean serum calcium was 9.2 +/- 0.8 mg/dL and at 6 months mean serum calcium, phosphorus, and PTH were 9.4 +/- 1.06 mg/dL, 3.2 +/- 0.8 mg/dL, and 32.1 +/- 11.9 pg/mL, respectively (p = 0.0001). There was no mortality. In 2 patients (1.4%) there was transient vocal cord paresis and there were 8 instances of clinically significant hypocalcemia. In 3 cases (2.1%), a second adenoma manifested itself 9-14 months following surgery and was removed by minimal access procedure. CONCLUSIONS: Minimally invasive, radio-guided focused parathyroidectomy for a single adenoma is safe and effective in curing hyperparathyroidism with a 97% success rate. A second adenoma occurring in less than 3% may be successfully treated with a second minimal access operation. The combined positive predictive value of concurring sestamibi SPECT scintigraphy and sonography of 99.2% may increase success rate, and thus implementing this technique in patients with concurring sonography and scintigraphy may be advocated.