Time-dependent molecular emission in IRC+10216

CONTEXT

The variability in IRC+10216, the envelope of the asymptotic giant branch (AGB) star CW Leo, has attracted increasing attention in recent years. Studying the details of this variability in the molecular emission required a systematic observation program.

AIMS

We aim to reveal and characterize the periodical variability of the rotational lines from several molecules and radicals in IRC+10216, and to compare it with previously reported IR variability.

METHODS

We carried out systematic monitoring within the ~80 to 116 GHz frequency range with the IRAM 30m telescope.

RESULTS

We report on the periodical variability in IRC+10216 of several rotational lines from the following molecules and radicals: HC3N, HC5N, CCH, C4H, C5H, and CN. The analysis of the variable molecular lines provides periods that are consistent with previously reported IR variability, and interesting phase lags are revealed that point toward radiative transfer and pumping, rather than chemical effects.

CONCLUSIONS

This study indicates that observations of several lines of a given molecule have to be performed simultaneously or at least at the same phase in order to avoid erroneous interpretation of the data. In particular, merging ALMA data from different epochs may prove to be difficult, as shown by the example of the variability we studied here. Moreover, radiative transfer codes have to incorporate the effect of population variability in the rotational levels in CW Leo.

p27Kip1 Inactivation Provides a Proliferative Advantage to Transplanted Hepatocytes in DPPIV/Rag2 Double Knockout Mice after Repeated Host Liver Injury

Studies were conducted to develop a new DPPIV–/–/Rag2–/– mouse model for hepatocyte transplantation by allogeneic and xenogeneic cells and to compare the proliferative capacity of p27 null hepatocytes versus normal hepatocytes in this system. Dipeptidyl peptidase IV (DPPIV) gene knockout mice, in which wild-type (wt) DPPIV+ donor hepatocytes can be readily identified by enzyme histochemistry, were bred with Rag2 null mice to prepare immunotolerant DPPIV–/–/Rag2–/– double knockout mice. DPPIV–/–/Rag–/– mice were transplanted with wt hepatocytes or p27 null mouse hepatocytes, which show enhanced cell cycle activity due to disruption of the Kip1 cyclin kinase inhibitor gene, and liver repopulation was assessed under nonproliferative versus proliferative experimental conditions. After their initial engraftment, transplanted wt hepatocytes did not proliferate in untreated livers or increase significantly in response to an acute liver regenerative stimulus. p27 null hepatocytes engrafted with the same efficiency as wt hepatocytes, but showed a noticeable, although not statistically significant, increase in proliferation in response to partial hepatectomy or acute CCl4 administration. Repeated treatments with CCl4 substantially increased proliferation and liver repopulation by p27 null hepatocytes but not by wt hepatocytes. These results suggest that p27 gene inactivation does not overcome proliferative restrictions imposed on hepatocytes by the normal liver, but that after repeated episodes of toxic liver injury, the augmented proliferative capacity of p27 null hepatocytes leads to significant liver repopulation compared with wt hepatocytes. These properties of p27-deficient hepatocytes could prove useful as a target for liver repopulation in patients with intermittent or a low level of chronic liver injury.

Assessment of surgical discharge summaries and evaluation of a new quality improvement model

BACKGROUND

Discharge summaries after hospitalization provide the most reliable description and implications of the hospitalization. A concise discharge summary is crucial for maintaining continuity of care through the transition from inpatient to ambulatory care. Discharge summaries often lack information and are imprecise. Errors and insufficient recommendations regarding changes in the medical regimen may harm the patient's health and may result in readmission.

OBJECTIVES

To evaluate a quality improvement model and training program for writing postoperative discharge summaries for three surgical procedures.

METHODS

Medical records and surgical discharge summaries were reviewed and scored. Essential points for communication between surgeons and family physicians were included in automated forms. Staff was briefed twice regarding required summary contents with an interim evaluation. Changes in quality were evaluated.

RESULTS

Summaries from 61 cholecystectomies, 42 hernioplasties and 45 colectomies were reviewed. The average quality score of all discharge summaries increased from 72.1 to 78.3 after the first intervention (P < 0.0005) to 81.0 following the second intervention. As the discharge summary's quality improved, its length decreased significantly.

CONCLUSIONS

Discharge summaries lack important information and are too long. Developing a model for discharge summaries and instructing surgical staff regarding their contents resulted in measurable improvement. Frequent interventions and supervision are needed to maintain the quality of the surgical discharge summary.

Discovery of Time Variation of the Intensity of Molecular Lines in IRC+10216 in The Submillimeter and Far Infrared Domains

We report on the discovery of strong intensity variations in the high rotational lines of abundant molecular species towards the archetypical circumstellar envelope of IRC+10216. The observations have been carried out with the HIFI instrument on board Herschel and with the IRAM 30-m telescope. They cover several observing periods spreading over 3 years. The line intensity variations for molecules produced in the external layers of the envelope most probably result from time variations in the infrared pumping rates. We analyze the main implications this discovery has on the interpretation of molecular line emission in the envelopes of Mira-type stars. Radiative transfer calculations have to take into account both the time variability of infrared pumping and the possible variation of the dust and gas temperatures with stellar phase in order to reproduce the observation of molecular lines at different epochs. The effect of gas temperature variations with stellar phase could be particularly important for lines produced in the innermost regions of the envelope. Each layer of the circumstellar envelope sees the stellar light radiation with a different lag time (phase). Our results show that this effect must be included in the models. The sub-mm and FIR lines of AGB stars cannot anymore be considered as safe intensity calibrators.

Laparoscopic repair of giant diaphragmatic hernias: evolving technical aspects and outcomes

BACKGROUND

Laparoscopic repair of giant diaphragmatic hernias (GDH) can be challenging, especially when partial or complete volvulus of the herniated stomach is encountered.

OBJECTIVES

To review our experience with laparoscopic repair of GDH, emphasizing preoperative investigation, technical aspects, and outcome.

METHODS

We conducted a retrospective review of patients operated on for GDH who were diagnosed when at least half the stomach was found in the mediastinum at surgery. Technical aspects and surgical outcomes were evaluated.

RESULTS

Fifty patients underwent laparoscopic GDH repair during an 8 year period. Four patients admitted with acute symptomatic volvulus of the stomach were initially treated by endoscopic decompression followed by surgery during the same admission. Two cases were converted to open surgery. Initial surgery was successful in 45 patients; 3 had an immediate recurrence, 1 was reoperated for dysphagia during the same admission, and 1 had a mediastinal abscess. During long-term follow-up, six patients required reoperation for recurrent hernias. Another four patients had asymptomatic partial herniation of the stomach. The main reason for failure was incomplete reduction of the hernia sac, especially the posterior component. No correlation was found between the type of repair and surgical failure. Most patients who did not undergo an anti-reflux procedure had postoperative reflux unrelated to their preoperative workup.

CONCLUSIONS

Laparoscopic repair of GDH is challenging, but practical and safe. It should be the treatment of choice for this potentially life-threatening condition. Careful attention to pitfalls, such as the posterior element of the sac, and routine performance of an anti-reflux procedure are crucial.

Hydride spectroscopy of the diffuse interstellar medium: new clues on the gas fraction in molecular form and cosmic ray ionization rate in relation to H3+

The Herschel-guaranteed time key programme PRobing InterStellar Molecules with Absorption line Studies (PRISMAS)(1) is providing a survey of the interstellar hydrides containing the elements C, O, N, F and Cl. As the building blocks of interstellar molecules, hydrides provide key information on their formation pathways. They can also be used as tracers of important physical and chemical properties of the interstellar gas that are difficult to measure otherwise. This paper presents an analysis of two sight-lines investigated by the PRISMAS project, towards the star-forming regions W49N and W51. By combining the information extracted from the detected spectral lines, we present an analysis of the physical properties of the diffuse interstellar gas, including the electron abundance, the fraction of gas in molecular form, and constraints on the cosmic ray ionization rate and the gas density.

Conservative treatment of right-sided colonic diverticulitis

BACKGROUND

Diverticulosis of the right colon occurs in a small percentage of patients in Western countries. Clinical presentation of right-sided colon diverticulitis is indistinguishable from that of acute appendicitis, and the majority of patients undergo surgical intervention for presumed appendicitis. The liberal use of diagnostic radiological modalities whenever appendicitis was suspected led to correct diagnosis and also to more preoperative diagnosis of right-sided diverticulitis, which consented conservative medical therapy in cases of uncomplicated right-sided diverticulitis. The aim of the study was to report the outcome in patients with right-sided diverticulitis diagnosed nonoperatively using computed tomography scanning and treated conservatively.

METHODS

Patients with clinical and radiological diagnosis of cecal or right colon diverticulitis treated conservatively between January 2005 and December 2007 were included. The demographic and clinical data were retrospectively analyzed.

RESULTS

Fifteen patients were included in this study. The median age was 52 years (range, 34-72 years) and the duration of symptoms was 4 days (range, 1-9 days) before the diagnosis. The median hospital stay was 5 days (range, 1-9 days). All patients were successfully treated with medical therapy. During a median follow-up of 32 months (range, 24-52 months) only one patient (6.6%) had a recurrent attack, and he was successfully treated again with medical therapy.

CONCLUSION

The routine use of the computed tomography scan for abdominal pain in the right lower quadrant, and whenever right-sided diverticulitis is suspected, improves diagnosis and reduces surgical interventions. The current study provides additional data in support of conservative therapy as the initial treatment in acute right-sided diverticulitis, even in cases of recurrence.

[Laparoscopic management of peritoneal dialysis catheters]

INTRODUCTION

Peritoneal dialysis (PD) is one of the established methods for the management of patients with end-stage renal failure. Laparoscopy has been used to assist in the insertion of new catheters as well as for the salvage of malfunctioning peritoneal dialysis catheters (PDC).

OBJECTIVES

The purpose of this retrospective study was to review our experience in the utilization of laparoscopy for the management of PDC.

METHODS

We reviewed the charts of all consecutive patients who had undergone either a ap-assisted insertion of a PDC utilizing a modified peritoneoscopic Y-TEC [Medigroup, Inc, Oswego, Ill) technique (YT) under direct laparoscopic vision or laparoscopic-assisted procedures for the salvage of a malfunctioning PD catheter.

RESULTS

Twenty nine patients had undergone 43 procedures that included the insertion of a new PD catheter using the modified YT technique, YT with simultaneous adhesiolysis and omentectomy; YT with repair of an epigastric hernia, omentectomy, adhesiolysis and repositioning of PDC; and ravage and repositioning of the obstructed PD catheter in all patients who needed repositioning of the catheter, the PDC was fixed with an intraperitoneal suture to the lower anterior abdominal wall. Postoperatively, malfunction of the catheter was found in one patient due to reclotting of PDC caused by oozing as a result of extensive adhesiolysis. One patient needed emergent laparotomy due to small bowel perforation that was missed during a difficult laparoscopic adhesiolysis.

CONCLUSIONS

Laparoscopic surgery may be helpfuL for the diagnosis and the management of a malfunctioning PDC. A modified YT technique is safe and may be one of the alternative methods for the placement of a PDC.

Management of acute appendicitis: an imaging strategy in children

The pre-operative diagnosis of acute appendicitis (AA) has markedly changed during the last couple of decades due to the advent of modern imaging technology. Nowadays, the use of imaging has dramatically changed the way we approach children admitted to emergency room for abdominal pain with suspected AA. This change is mainly manifested in our diagnostic strategy.

Young-age onset of colorectal cancer in Israel

AIM

The study was conducted to investigate the differences in clinical-pathological, ethnic, and demographic presentations and the expression of mismatch repair proteins in a cohort of young-onset (</=50 years) versus late-onset Israeli patients (>50 years) with colorectal cancer.

MATERIALS AND METHODS

Clinical, demographic, and histopathological data of patients with colorectal cancer were collected retrospectively from medical records and pathology reports.

RESULTS

Ninety patients, 50 years of age or younger with a mean age of 42 years were compared with a group of 190 patients above 50 years of 50 (see Table 1). Sixty percent of the young-onset patients were females, compared to 40% in the older age group (P = 0.02). Twenty-one percent of the young-onset patients were Arabs as compared to 2% of older-onset patients (P = 0.001). Younger patients displayed a higher percentage of mucinous cancers and a higher percentage of diagnosis at an advanced stage of disease; 40% of young-onset versus 31% of older-onset patients presented Duke's stages C and D (P = 0.02).

CONCLUSIONS

Younger age of onset colorectal cancer in our cohort of Israeli patients is associated with higher percentage of Arab patients, mucinous cancers, female gender, and advanced stage at diagnosis.

Emergency surgery for complicated acute diverticulitis

AIM

Antecedent attacks of diverticulitis are thought to increase the risk of complicated diverticulitis, and unless elective surgery is performed, a high proportion of patients with recurrent symptoms will require emergency operations for complicated diverticulitis with its associated morbidity. In this multicentre study, we aim to assess impact of previous attacks of diverticulitis on patients requiring an emergency surgical intervention.

METHOD

All patients operated on as an emergency for complicated diverticulitis were retrospectively analysed. Patients were separated into two groups: group A included patients without previous history of diverticular disease, and group B those with previous attacks of diverticulitis.

RESULTS

A total of 96 patients were included in the study. Group A included 68 (70.8%) patients, and group B 28 (29.2%) patients. Generalized peritonitis was the reason for operation in 50 (73.5%) patients in-group A and only four (14%) patients in group B. Perforated diverticulitis occurred more often in group A, whereas pericolonic abscess and phlegmon formation occurred more commonly in group B. Resection was performed in all patients in group B; 50% had a Hartmann's procedure, and the other 50% patients had primary anastomosis. Hartmann's procedure was performed in 52 patients (76.5%) in group A, and 8 patients (11.7%) had resection and primary anastomosis. No difference in postoperative complications was identified between the groups.

CONCLUSION

Multiple attacks of diverticulitis are not associated with an increased risk of complicated diverticulitis. Recurrent episodes of diverticulitis are not associated with a less favourable outcome or an increased risk of fatality if complications ensue.

Specimen length as a perioperative surrogate marker for adequate lymphadenectomy in colon cancer: the surgeon's role

The objective of this study was to determine whether there is a correlation between the length of the sigmoid colon removed and the number of harvested lymph nodes (LNs). Pathology charts of 137 sigmoid resections that were done over a 5-year period were reviewed. The length of removed sigmoid specimen reported in the pathology reports was correlated with the number of LNs retrieved from the specimen. The mean and median numbers of retrieved LNs were 9 and 10, respectively. There was an increase in the number of retrieved LNs with increasing length of resected sigmoid colon. For Dukes' B patients, the average length of the resected specimen was 15.1 cm for those with < 12 LNs and 20.3 cm for those with > 12 LNs (P = 0.01). Our data suggest that the surgeon may play an important role in determining the extent of LN harvesting during large bowel resection for cancer.

Abdominal wall abscesses in patients with Crohn's disease: clinical outcome

Abdominal wall abscess due to Crohn's Disease used to be one of the definitive indications for operative treatment. The advent of interventional radiology, the accessibility to percutaneous drainage, and the availability of new medications raised the possibility of nonoperative treatment of this condition. The clinical presentation, treatment, and follow-up of 13 patients with abdominal wall abscesses secondary to Crohn's Disease were retrospectively reviewed. During a 10-year period (1993-2003), 13 patients with abdominal wall abscess were treated. Five patients had an anterolateral abdominal wall abscess and eight had a posterior abscess (psoas). In 11 patients, 17 drainage procedures were performed: 12 percutaneous and 5 operative. Despite initial adequate drainage and resolution of the abscess, all 13 patients eventually needed resection of the offending bowel segment, which was undertaken in 12 patients. The mean time between abscess presentation and definitive operation was 2 months. Percutaneous drainage is an attractive option in most cases of abdominal abscesses. However, in Crohn's Disease patients with an abdominal wall abscess, we found a high failure rate despite initial adequate drainage. We suggest that surgical resection of the diseased bowel segment should be the definitive therapy.

Prospective, multicenter evaluation of highly concentrated fibrin glue in the treatment of complex cryptogenic perianal fistulas

PURPOSE

The surgical management of complex perianal fistulas is challenging and may be associated with the risk of sphincter injury. Instillation of fibrin glue to the fistula tract is a simple procedure that does not involve any muscle division, and potentially results in healing of the fistula. This study was designed to assess the use of highly concentrated fibrin glue with intra-adhesive antibiotics in the treatment of complex cryptogenic perianal fistulas.

METHODS

Patients with complex perianal fistulas of cryptogenic origin were prospectively included in this multicenter study. Injection of the fibrin glue mixed with antibiotics was performed in a uniform fashion. After the procedure, patients were actively examined at fixed time intervals; in cases of recurrent fistula, reinjection of fibrin glue was offered.

RESULTS

Sixty patients were enrolled; complete healing of the fistula was achieved in 32 patients (53 percent). Eight of 28 patients (29 percent) who were not completely healed had significant symptomatic improvement. All patients resumed normal daily activity the day after surgery and none had any deterioration in continence related to the procedure. The majority of the 26 (43 percent) adverse events were considered mild and spontaneously resolved; 2 patients (3 percent) with perianal septic complications were successfully treated by drainage.

CONCLUSIONS

Injection of fibrin glue for the treatment of perianal fistulas is safe, simple, and associated with early return to normal activity. Although moderately successful, it may preclude extensive surgery in more than one-half of these patients.

Suppressive effect of aspirin on aberrant crypt foci in patients with colorectal cancer

BACKGROUND

and aims: Aspirin and other non-steroidal anti-inflammatory drugs have been shown to reduce the risk of colorectal cancer (CRC). Animal models have shown that aspirin is also effective in reducing the density of aberrant crypt foci (ACF). The aim of the study was to evaluate the effect of chronic administration of aspirin on the distribution pattern and histological characteristics of ACF in patients with CRC.

METHODS

Our study compared the distribution patterns and histomorphological characteristics of ACF between a group of CRC patients treated with low dose aspirin (n=59) and a control group without aspirin (n=135). ACF were visualised on methylene blue stained macroscopically normal mucosa, microdissected, and serially cut.

RESULTS

ACF were found in 75.8% of mucosal samples from the control group and in 36% of mucosal samples from the aspirin treated group, indicating a 47% decline in prevalence of ACF in colonic samples of patients treated with aspirin. A significant reduction from 92.5% to 40% (p<0.0001) was found in distal large bowel samples containing one or more ACF. Similarly, the aspirin treated group showed a reduction in ACF density of 64% and 82%, respectively, in both proximal and distal parts of the colon, indicating a significant reduction in ACF/cm(2) in distal colon samples (p<0.01). The aspirin treated group displayed a 52% reduction in dysplastic ACF although this difference was not statistically significant.

CONCLUSIONS

Our study has provided evidence of the effective chemopreventive action of low dose aspirin on ACF in humans.

Angiogenic switch in earliest stages of human colonic tumorigenesis

BACKGROUND

Angiogenesis is activated in numerous physiological and pathological conditions. We examined whether new vessel formation exists in the earliest stages of colonic tumorigenesis.

MATERIALS AND METHODS

Microvascular density (MVD) was examined in 176 formalin-fixed and paraffin-embedded aberrant crypt foci (ACF) dissected from macroscopically-normal mucosa obtained from patients with colorectal cancer. ACF were classified as non-hyperplastic, non-dysplastic (NH-ACF, n = 80), hyperplastic (H-ACF, n = 72) and dysplastic (D-ACF, n = 24). Mucosal strips were stained with methylene blue solution and screened under x 40 magnification for ACF. The identified ACF were microdissected and stained with an anti-CD-34 monoclonal antibody. MVD in ACF were compared to that of normal corresponding mucosa.

RESULTS

The mean MVD for normal mucosa and ACF were 13.7 +/- 7.7 and 23 +/- 13, respectively. Microvessel counts increased in NH-ACF versus normal mucosa (18.7 +/- 10 vs. 13.7 +/- 7.7, p = 0.05), in H-ACF versus NH-ACF (24.8 +/- 14 vs. 18.7 +/- 10, p = 0.002) and in D-ACF versus H-ACF (31.7 +/- 10 vs. 24.8 +/- 14, p = 0.014). We further evaluated the effect of low-dose aspirin on MVD in ACF. No effect of aspirin on microvessel counts could be detected.

CONCLUSION

Our data suggest that angiogenesis occurs in ACF which are the earliest morphologically identifiable preneoplastic and early neoplastic lesions in colonic mucosa. With progression from NH-ACF to D-ACF there is a progressive, statistically significant increase in MVD, suggesting active angiogenesis during the earliest steps of colorectal tumorigenesis.

[Laparoscopic cholecystectomy--1,000 procedures in a surgical department]

The first 1,000 laparoscopic cholecystectomies performed in our department were reviewed. There was no operative mortality; conversion to open cholecystectomy was necessary in 2%. In the last 600 cases the rate of conversion had decreased to 0.5%. There was common bile duct injury in 0.3%, with the injuries identified during primary surgery. This clinical experience is consistent with previous studies, which proved that laparoscopic cholecystectomy is safe and should replace open operation as the procedure of choice.

Octreotide treatment in patients with severe acute pancreatitis

We investigated the effect of octreotide in the treatment of severe acute pancreatitis in a case-control study. Experimental and clinical studies on the effect of octreotide in the treatment of acute pancreatitis have shown controversial results. Since January 1992, we have been conducting a prospective randomized study on the effect of octreotide in severe acute pancreatitis, in three hospitals in Israel. The entering criteria included three or more of the Ranson prognostic signs and CT findings of severe pancreatitis. Patients were randomly assigned to conservative treatment either with or without octreotide (0.1 mg subcutaneously three times a day). The end points of the study included: complication rate (ARDS, sepsis, renal failure, pseudocyst, fistula, and abscess), length of hospital stay, and mortality. From January 1992 to December 1996, 60 patients entered the study. After evaluating the files, 10 patients were excluded due to failure to meet the entering criteria, incomplete data, or incorrect diagnosis. Of the remaining 50 patients, 25 were assigned to octreotide (treatment group) and 25 to conservative treatment only (control group). The two groups matched with regard to age, sex, etiology, and severity of the disease. The complication rate was lower in the treatment group with regard to sepsis (24% vs 76%, P = 0.0002) and ARDS (28% vs 56%, P = 0.04). The hospital stay was shorter in the treatment group (20.6 vs 33.1 days, P = 0.04). Two patients died in the treatment group and eight in the control group (P < 0.019). These results suggest that octreotide may have a beneficial effect in the treatment of severe acute pancreatitis.

Specificity of TUNEL method depends on duration of fixation

Recent evidence has suggested that apoptosis plays an important role in various diseases, but concerns about the specificity of the TUNEL method for detecting apoptosis have been raised. The purpose of the present study was to investigate the specificity of the TUNEL method by using immersion and perfusion fixed tissues from both normal rats and rats with heart failure. Although a few positive cells were observed in perfusion fixed tissues, a significant number of positive cells were observed in immersion fixed tissues, especially when fixed tissues were kept for an extended time before the TUNEL assay was applied. The results of TUNEL staining should be interpreted with caution. When immersion fixation is used, fixed tissues should be assayed by the TUNEL method before the DNA degenerates.

Is apoptosis present in progression to chronic hypertensive heart failure?

BACKGROUND

Cardiomyocyte apoptosis is believed to occur in hypertension. Isolated myocyte data from spontaneously hypertensive heart failure (SHHF) rats, however, suggest that significant myocyte loss does not occur in this model. To investigate this issue further, heart sections from failing and nonfailing SHHF rats were examined by using in situ terminal deoxynucleotidyltransferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labeling (TUNEL). Additional hearts were optimally fixed by perfusion with glutaraldehyde and histologically examined for evidence of myocyte damage or loss.

METHODS AND RESULTS

Five Sprague-Dawley (SD) rats, 8 failing SHHF rats, and 6 nonfailing SHHF rats were perfusion-fixed with formaldehyde and used for TUNEL assay. Heart sections from each group were also treated with DNase for positive controls. There were no significant differences in the number of TUNEL-positive cells in SD, failing SHHF, and nonfailing SHHF rats. Additionally, extensive screening of 1-microm sections of optimally fixed failing hearts revealed little evidence of myocyte loss or nuclear characteristics suggestive of apoptosis.

CONCLUSION

Apoptosis does not appear to be an important component of myocardial remodeling in SHHF rats during hypertrophy or end-stage heart failure. Examination of myocyte nuclear structure by high-resolution microscopy of optimally fixed tissues is recommended as an alternative approach to study apoptosis.

Treatment of acute colonic pseudo-obstruction with neostigmine

BACKGROUND

Colonic pseudo-obstruction is a poorly understood syndrome, described by Ogilvie, and characterized by signs of large-bowel obstruction, without a mechanical cause. An imbalance in the autonomic nerve supply to the colon has been suggested as the pathophysiology. Recently, promising results with pharmacologic manipulation with neostigmine have been described.

STUDY DESIGN

A prospective study was undertaken with 11 consecutive patients with clinical and radiologic signs of colonic pseudo-obstruction, in one general hospital, over a 1-year period. Patients were treated primarily with 2.5 mg of neostigmine in 100 mL of saline for 1 hour, under cardiac monitoring. Results were assessed by the clinical and radiologic responses.

RESULTS

Rapid and effective spontaneous decompression of the colon was achieved in 8 patients after a single dose of neostigmine, within a mean of 90 minutes from the beginning of treatment. In another two patients decompression occurred only after a second dose was administered 3 hours after the first dose. In one patient, no changes were observed and colonoscopic decompression was performed. No significant bradycardia was observed in any of the patients.

CONCLUSIONS

Neostigmine is a simple, safe, and effective therapy for treatment of colonic pseudo-obstruction.

Enema-induced perforation of the rectum in chronically constipated patients

INTRODUCTION

The use of retrograde irrigation enemas is common in the treatment of chronic constipation, especially in the elderly. Perforation of the rectum and sigmoid colon caused by cleansing enemas, used by chronically constipated patients, has not been previously described.

METHODS

We reviewed all patients with colorectal perforations caused by irrigation enemas admitted to our service in the three-year period between January 1995 and December 1997.

RESULTS

Thirteen patients were treated by our surgical service because of perforations of the rectum and sigmoid colon related to a previous retrograde irrigation enema. Ten of these patients came from nursing homes, and the other three lived at home. The relevant information relating the enema administration to the patient's condition was given in only two of the ten patients referred to the emergency room by the institution's nursing or medical staff. In the other eight the information was vague and sometimes misleading. The diagnosis of colorectal perforation was made by history, plain abdominal x-rays, and CT scan with or without meglumine diatrizoate enemas. Ten patients survived, regardless of age, previous diseases, or operative findings. In all of them, diagnosis was made within 36 hours from the perforation. The three deaths occurred in patients in whom the diagnosis was made late.

CONCLUSIONS

Awareness of the possible injury from enemas administered to chronically constipated patients should be stressed. A high degree of suspicion by the attending physician is extremely important, because prompt diagnosis and early surgical treatment carries a relatively good prognosis.

THE EFFECT OF THE SOMATOSTATIN ANALOGUE OCTREOTIDE ON EXPERIMENTAL INTESTINAL OBSTRUCTION IN RATS

Background: Somatostatin has an inhibitory effect on the endocrine and exocrine secretions of the gut. It may have a beneficial effect in the conservative treatment of intestinal obstruction. The aim of the present study is to investigate the effect of octreotide in mechanical intestinal obstruction in rats. Method: Intestinal obstruction was induced in rats by ligation of a segment of the distal ileum. Animals were treated with the somatostatin analogue octreotide (n=16), or saline (n=16). Eight rats were operated but their intestine was not ligated (n=8) serving as sham controls. Forty eight hours after the operation, the animals were operated upon again and blood samples from the femoral vein were tested for electrolytes, urea, glucose, lactic acid, amylase, ph and bicarbonate. Portal vein blood samples were also obtained and tested for lactic acid and amylase. Results: Intestinal obstruction resulted, after 48 hours, in severe dilatation of bowel loops. A significant increase in plasma levels of urea, amylase and lactic acid was observed. Plasma pH decreased. In blood samples from the portal vein, a significant increase in lactic acid was observed, indicating metabolic acidosis, probably secondary to bowel ischemia. Octreotide treatment, resulted in less acidosis, with concomitant lower urea and lactic acid levels in the plasma and especially in the portal vein. Conclusion: Octreotide treatment may have a beneficial effect in the conservative treatment of selected cases of intestinal obstruction.

Aberrant crypt foci in human colons: distribution and histomorphologic characteristics

Aberrant crypt foci (ACF) are one of the earliest putative preneoplastic, and in some cases, neoplastic lesions in human colons. These microscopic lesions, identified on methylene blue-stained mucosa with a low-power-magnification microscope, are thought to be closely related to the earliest steps in multistage colonic tumorigenesis. We investigated the distribution pattern and histomorphological features of ACF in 74 patients with sporadic colorectal cancer. The distribution pattern shows a slightly higher prevalence with older age. The prevalence of the ACF in sigmoid colon was significantly higher in patients with colorectal cancer as compared with patients with benign colonic diseases. Also, significantly more ACF were detected in distal parts of the large bowel (descending, sigmoid colon, and rectum) than in proximal parts. Of 42 microdissected lesions, 12 were dysplastic and 30 were hyperplastic foci. The average size of dysplastic lesions was significantly larger than hyperplastic foci. More apoptotic bodies were found in dysplastic lesions. These lesions also showed an upward expansion of proliferative compartment and higher proliferation indices expressed as proliferating cell nuclear antigen-labeling index. Lymphoid follicles were frequently observed in the base of both hyperplastic and dysplastic foci (40% and 66.6%, respectively). The coincidence of lymphoid follicles was 2.5 to 8 times higher than expected. These features may be related to further progression of selected ACF during colorectal tumorigenesis.

Effect of cyclical salinity changes on cell volume and function in geukensia demissa gills

We acclimated the estuarine mussel Geukensia demissa to a regime of sinusoidal salinity cycling (12 h cycle between 100 % and 60 % seawater) and correlated changes in the volume of gill cells with changes in several indicators of the functional status of gill cells (rate of O2 consumption, ATP content and amino acid transport). There was no indication of short-term volume regulation in the gill cells of mussels acclimated to salinity cycling. When exposed to cycling salinity, cell water space consistently increased to approximately 3 ml g-1 dry mass during the cycle troughs (60 % seawater) and returned to approximately 2 ml g-1 dry mass at the cycle peaks (100 % seawater). In mussels acclimated for 2 weeks to cycling salinity, the gill contents of betaine, taurine and K+ were unchanged (approximately 240, 230 and 160 micromol g-1 dry mass, respectively) between the 60 % and 100 % seawater portions of the salinity cycle. The changes in cell volume did not appear to be associated with large perturbations in the functional status of cells. The rate of O2 consumption was approximately 100 microl O2 g-1 dry mass min-1, and ATP content was approximately 30 micromol g-1 protein, in all salinities to which mussels were exposed. Rates of uptake of taurine, leucine and phenylalanine decreased by approximately 50 % during the first sinusoidal decrease to 60 % seawater, but recovered following re-exposure to 100 % seawater. Uptake rates of all three amino acids were unaffected by any subsequent salinity cycles. These results suggest (1) that the regulation of gill cell volume is normally absent from mussels exposed to repeated, gradual salinity changes, and (2) that any effects of changes in cell volume are not severe enough to justify the energetic expenditure that would be associated with repeated regulation of cell volume. Unlike the response of gill cells to cycling salinity, there was a decrease in the solute contents of ventricles during the salinity troughs compared with the salinity peaks, suggesting that the presence of short-term volume regulation may be more critical in the ventricle.

Long-term reduction of serum bilirubin levels in Gunn rats by retroviral gene transfer in vivo

Conjugation with glucuronic acid, mediated by bilirubin-uridinediphosphoglucuronate glucuronosyltransferase (bilirubin-UGT), is essential for efficient biliary excretion of bilirubin. Inherited absence of this enzyme activity results in the potentially lethal Crigler-Najjar syndrome type I in humans and lifelong hyperbilirubinemia in Gunn rats. To develop a gene therapy for bilirubin-UGT deficiency, we constructed a high-titer replication-deficient amphotropic recombinant retrovirus (MFG-S hB-UGT1) capable of transferring the gene encoding bilirubin-UGT1, the principal bilirubin-UGT isoform in human liver. To stimulate hepatocyte proliferation, Gunn rats were subjected to 66% hepatectomy. After 24 hours, the portal vein, the hepatic artery, and the inferior vena cava above and below the hepatic vein were clamped, and the portal vein and the isolated segment of the vena cava were cannulated. The liver was perfused with the MFG-S hB-UGT1 preparation through the portal vein at 5 ml/min for 10 minutes, then circulation was restored. Control rat livers were perfused with a recombinant retrovirus expressing Escherichia coli beta-galactosidase. In MFG-S hB-UGT1-perfused rats, but not in controls, expression of human bilirubin-UGT1 was shown by immunotransblotting, bilirubin-UGT assay of liver homogenates, and biliary excretion of bilirubin diglucuronide and monoglucuronide. Mean serum bilirubin levels decreased by 20% to 25% in 3 weeks and remained at that level throughout the study period (18 months). This is the first report of long-term amelioration of inherited jaundice by retrovirus-directed gene therapy in an animal model for Crigler-Najjar syndrome.

[Laparoscopic cholecystectomy in acute cholecystitis]

We performed 417 laparoscopic cholecystectomies, including 58 for acute cholecystitis, between September 1991 and April 1995,. All operations were successful, with no mortality or complications. In about 10%, the laparoscopic approach failed and we converted to open cholecystectomy. Average post-operative hospitalization was 24 hours. We also performed primary open cholecystectomies in 55 patients with acute cholecystitis, because of limitations of operating room and staff availability for unscheduled laparoscopic surgery. In these patients, hospital stay was longer and rate of complications higher. In our opinion laparoscopic cholecystectomy is safe and the preferred approach in acute cholecystitis.

Perforation of the terminal ileum induced by blast injury: delayed diagnosis or delayed perforation?

Blast injuries are rare, and although blast-induced perforations of the bowel have been described in the past, the entity of a delayed perforation caused by an evolving injury has not been reported. We report three men injured by the explosion of a terrorist bombing in open air. They suffered primary blast injuries, which resulted in isolated perforations of the terminal ileum. They were operated at different times after the blast event. The resected specimens were examined under light microscopy. One patient was operated immediately, and had three perforations in the terminal ileum. In the other two patients, abdominal complaints appeared only 24 and 48 hours later. These two patients were found to have hematomas in the wall of the terminal ileum, and small perforations therein, with almost no contamination of the peritoneal cavity. On histological examination, there were small perforations with disruption of all intestinal layers. In the vicinity of the perforations, the mucosa was necrotic and disorganized. The submucosa showed edema and vascular thrombi, and at several points mucus was shown dissecting through the muscularis propria, thus creating minute microperforations. Because of the findings in these patients, we suggest a mechanism of evolving damage to the bowel wall and delayed perforation rather than delayed diagnosis, after blast injuries. We suggest that patients exposed to a significant blast should be watched carefully for at least 48 hours.

Preliminary report of a prospective randomized study of octreotide in the treatment of severe acute pancreatitis

BACKGROUND

Experimental and clinical studies on the effect of octreotide in the treatment of patients with acute pancreatitis have presented controversial results. Since January 1992, we have been conducting a prospective randomized study on the clinical effect of octreotide in severe acute pancreatitis, at three hospitals in Israel.

STUDY DESIGN

The entering criteria included three or more of the Ranson's prognostic signs and computed tomographic findings of severe pancreatitis. Patients were randomly assigned to conservative treatment either with or without octreotide (0.1 mg injected subcutaneously three times a day). The end points of the study included: complication rate (adult respiratory distress syndrome [ARDS], sepsis, renal failure, pseudocyst, fistula, and abscess), length of hospital stay, and mortality.

RESULTS

During the first two years (from January 1992 to December 1993), 51 patients entered the study. After evaluation, 13 patients were excluded due to failure to meet the entering criteria, incomplete data, or incorrect diagnosis. Of the remaining 38 patients, 19 were assigned to octreotide (treatment group) and 19 to conservative treatment alone (control group). The two groups were matched with regard to age, sex, etiology, and severity of disease. The complication rate was lower in the treatment group compared with the control group with regard to sepsis (26 compared with 74 percent, p = 0.004) and ARDS (37 compared with 63 percent, p = 0.1). The hospital stay was shorter in the treatment group compared with the control group (17.9 compared with 34.1 days, p = 0.02). Death occurred in two patients in the treatment group and six patients in the control group.

CONCLUSIONS

Although some of the parameters did not reach statistical significance, these preliminary results suggest that octreotide may have a beneficial effect in the treatment of patients with severe acute pancreatitis. This study is scheduled to continue for two more years.

Evidence for a terminal differentiation process in the rat liver

In rapidly renewing epithelia, such as skin and gut, as well as hemopoietic cells and stromal fibroblasts, the process of progenitor cell maturation, terminal differentiation and senescence from cells of a fetal phenotype is strikingly similar. To examine hepatocellular maturation, we studied embryonic, suckling and young adult rat liver cells with multiparametric fluorescence activated cell sorting (FACS), after exclusion of hemopoietic, endothelial, Kupffer, and nonviable cells. With maturation, cell granularity and autofluorescence exponentially increased from fetal liver to suckling and adult liver as the proportion of S phase cells progressively declined from 33.8% +/- 1.3% to 4.9% +/- 2.8% and 1.1% +/- 0.6% (P < 0.05), respectively. In liver from fetal and suckling rats, all hepatocytes were mononuclear and contained diploid DNA whereas 21.2% +/- 5.9% hepatocytes in adult liver were binucleated. Analysis of nuclear DNA content in adult hepatocytes demonstrated that 53.3% +/- 3.9% of the nuclei were diploid, 43.6% +/- 3.5% tetraploid and 0.5 +/- 0.6% octaploid. However, in the adult liver, small, mononuclear cells were also present with granularity and autofluorescence comparable to fetal hepatoblasts, as well as glucose-6-phosphatase activity, diploid DNA in 89.0% +/- 2.1% of the nuclei, and with increased granularity in culture. Since general features of terminal cellularity differentiation and senescence include cessation of mitotic activity, polyploidy and accumulation of autofluorescent secondary lysosomes, our data suggest that liver cells too undergo a process of terminal differentiation.

Octreotide for treatment of postoperative alimentary tract fistulas

Eighteen patients with postoperative fistulas of the gastrointestinal tract were treated with the somatostatin analog octreotide between November 1989 and November 1992. Fourteen patients had enterocutaneous fistulas: seven from the duodenum and seven from the ileum. Another three patients had pancreatic fistulas, and one patient had a biliary fistula. Within 24 hours of octreotide treatment, a mean reduction of 52% in the intestinal fistulas' output, 40% in the pancreatic fistulas, and 30% in the biliary fistula was noted. In the intestinal fistulas group the closure rate was 72% after a mean of 11 days. Early closure (mean 6 days) was achieved in all three pancreatic fistulas. In the patient with the biliary fistula a 30% reduction was observed twice following the administration of octreotide, and an increase occurred when it was withheld. The reduction rate of the secretions in high-output intestinal fistulas (> 500 ml/day) was higher than in the low-output fistulas (63 +/- 8% versus 39 +/- 4%, p < 0.05). Fistula output and the initial response to octreotide treatment had no value in predicting spontaneous healing. In conclusion, octreotide is a valuable tool for the conservative treatment of fistulas of the digestive tract. It is especially valuable for management of high-output enteric fistulas and pancreatic fistulas.

EFFECT OF THE EXTERNAL CONCENTRATION OF CALCIUM ON THE POSTMOULT UPTAKE OF CALCIUM IN BLUE CRABS (CALLINECTES SAPIDUS)

The rate of calcium uptake in blue crabs (Callinectes sapidus Rathbun) acclimated to 2 sea water with a calcium concentration of 1.4 mmol l-1 was dependent on the magnitude and direction of the electrochemical gradient for calcium. When transferred to water with a high calcium concentration (6 mmol l-1), the electrochemical gradient for calcium favoured diffusive influx, and calcium uptake and apparent H+ excretion increased by approximately 50 %. When transferred to water with a low calcium concentration (0.10 mmol l-1), where the electrochemical gradient for calcium strongly favoured diffusive efflux, calcium uptake ceased but apparent H+ excretion continued at a reduced rate. Crabs regulated the free calcium concentration in their blood at approximately 8 mmol l-1 when the external concentration of calcium was 1.4 mmol l-1 or higher, but the concentration of free calcium in the blood decreased to 5.6 and 4.6 mmol l-1, respectively, at external concentrations of calcium of 0.25 and 0.10 mmol l-1. Crabs transferred to water with 0.10 mmol l-1 calcium for the first 2 days after moult accumulated only 2.5 g calcium kg-1 wet mass, about one-quarter of the mass normally accumulated. Seawater-acclimated crabs transferred to 2 salinity at 1 day postmoult took up calcium at a reduced rate, indicating that a period of acclimation is necessary for a component of the active transport system to increase its capacity, for diffusive efflux to be reduced, or for both to occur.

MECHANISM OF THE NET UPTAKE OF WATER IN MOULTING BLUE CRABS (CALLINECTES SAPIDUS) ACCLIMATED TO HIGH AND LOW SALINITIES

Blue crabs (Callinectes sapidus Rathbun) acclimated to a salinity of 2 approximately doubled in wet mass (excluding carapace) during the period from 10 h before moult to 2 h after moult. Both in blue crabs acclimated to 2 salinity and in crabs acclimated to 28 salinity, the drinking rate increased from approximately 0.4 ml 100 g-1 h-1 at 1 day prior to moult to approximately 8 ml 100 g-1 h-1 during the first hour after moult. The drinking rate had decreased 1 day after moult in both salinities, but was significantly higher in crabs acclimated to high salinity (1.84&plusmn;0.16 ml 100 g-1 h-1) than in crabs acclimated to low salinity (0.26&plusmn;0.04 ml 100 g-1 h-1). Drinking accounted for two-thirds of the weight gain during the first hour after moult at both acclimation salinities, indicating that water enters the body at moult primarily through the gut rather than through the gills. [14C]polyethylene glycol, added as a tracer in the bath water, was concentrated in the midgut gland rather than in the stomach, implicating the midgut gland as the primary site of water absorption. The rate of water efflux was significantly greater in crabs acclimated to 30 salinity (66.4&plusmn;9.0 ml 100 g-1 h-1) than in crabs acclimated to 2 salinity (34.0&plusmn;4.7 ml 100 g-1 h-1). The osmotic uptake of water is equal at both salinities as a result of the decreased water permeability at low salinity. The rate of urine formation was estimated to be between 0.5 and 1 ml 100 g-1 h-1 during the first hour after moult in crabs acclimated to both low and high salinities, suggesting that the antennal gland plays a relatively small role in water regulation during this period.

[Intra-operative cholangiography in laparoscopic cholecystectomy]

Intraoperative cholangiography (IC) in laparoscopic cholecystectomy is a controversial issue. According to traditional teaching, the purpose of cholangiography in gallbladder surgery is to discover previously undiscovered common bile duct stones. This examination was extremely important in the era before ERCP. IC enabled surgeons to find stones and remove them at the same operation. With progress in ERCP, the importance of intraoperative cholangiography has diminished. A stone missed during surgery can most often be dealt with by the less invasive ERCP and papillotomy. There has been a difference of opinion in the literature as to whether to perform cholangiography routinely during gallbladder operations or only in cases in which there is a specific indication, such as an enlarged common bile duct, a history of pancreatitis, or elevated enzymes. Routine operative cholangiography prolongs operative time and carries its own inherent risks, such as injury to the bile ducts. The likelihood of stones is not high and over-diagnosis of stones would result in unwarranted common bile duct exploration and the danger of complications from the procedure. The tendency today is towards a more selective approach. In this era of laparoscopic gallbladder surgery, the controversy has come to the fore again, and there is now an additional aspect. In laparoscopic gallbladder surgery there is greater significance to the "road map" provided by X-rays. We rely mainly on the visual sense and have forgone the tactile sense. Therefore, any added visual input in this operation helps avoid the danger of injuring the main bile ducts. It is our contention that the indications for operative cholangiography in laparoscopic cholecystectomy should again be broadened.

Rectus sheath hematoma: a complication of laparoscopic cholecystectomy

We describe a complication in laparoscopic cholecystectomy. The routine introduction of a midclavicular secondary trocar resulted in a large hematoma of the rectus sheath. The patient developed atelectasis and pneumonia and required extended hospitalization. This previously described complication is detailed with recommendations to prevent its occurrence.

Seasonal pattern in the incidence of bleeding caused by peptic ulcer in Israel

We have reviewed all endoscopies performed in our hospital between 1977 and 1986. During that period, 1337 endoscopies were performed to identify bleeding from peptic ulcers. Excluded were cases in which a predisposing factor was found, such as the use of ulcerogenic drugs. Also excluded were chronic or critically ill patients. The remaining 540 cases were reviewed. In 447 of those cases, the bleeding lesion was a duodenal ulcer, whereas, in 93 cases, a gastric ulcer was found (a ratio of 5:1). The seasonal variation in the incidence of bleeding from peptic ulcers was evaluated. We found a significant difference in bleeding in the cold and hot seasons, the incidence being significantly greater during the cold season (November until February). A similar pattern was found for bleeding from both duodenal and gastric ulcers.

Thyrotropin receptor autoantibodies induce human thyroid cell growth and c-fos activation

Graves' disease encompasses hyperthyroidism and a diffuse goiter associated with autoantibodies to the TSH receptor (TRAb). Although the cause of the goiter formation has been attributed to TRAb, the limited growth pattern of human adult thyroid cells in vitro has caused such a conclusion to be based on studies of nonhuman thyroid cell growth. We have recently characterized a predictable and precise technique for the measurement of human thyroid cell proliferation and function using fetal thyroid cells and have used this system to examine the influence of TRAb on human thyroid cell growth. Highly purified human immunoglobulin G (hIgG) preparations from normal individuals (n = 5) had no significant influence on human thyroid cell growth. However, hIgG from patients with detectable TRAb (TRAb-hIgG) (n = 13) induced a dose-related increase in extracellular cAMP (maximum effect at 0.1 mg/ml) and a 3-fold increase in human thyroid cell growth over a 4-day period (maximum effect at 1.5 mg/ml). Under basal thyroid cell culture conditions there were detectable, but low, levels of mRNA specific for the protooncogene c-fos, and this was markedly, and rapidly, induced by the addition of TRAb-hIgG but not normal hIgG. These data demonstrate induction of cellular growth by TRAb-hIgG in an homologous human thyroid cell culture system. Such observations support the hypothesis that goiter formation in patients with Graves' disease is, at least in part, secondary to the growth stimulating activity of TRAb-hIgG.

[Use of somatostatin analogue for intestinal and pancreatic fistulas]

The hormone somatostatin, a tetra-deca-peptide, was discovered in 1972. It inhibits the central nervous system and the endocrine and exocrine secretions of the gastrointestinal tract. The first clinical use of the hormone was to inhibit hormone-secreting tumors of the CNS. It has also been used to treat hormone-secreting tumors of the pancreas and GI tract. Treatment of small bowel and pancreatic fistulas has also been attempted. A new synthetic analogue of the hormone, SMS 210-995, (Sandostatin) has a long half-life and is highly effective after subcutaneous injection. It was used in the treatment of 3 patients with fistulas of the small bowel and pancreas. In all impressive reduction of fistula secretion was achieved within 24 hours. In 2 there was complete, spontaneous closure of the fistula: in 1 after 10 days and in the other after 15 days of treatment. In the 3rd, there was significant reduction of fistula output. There were no side-effects except for mild pain at the injection site in 1 patient. Previous reports and our own results indicate that this somatostatin analogue may be very useful in the nonsurgical treatment of GI tract fistulas.