Early major complications after bariatric surgery in the USA, 2003-2014: a systematic review and meta-analysis.

The effectiveness of bariatric surgery has been well-studied. However, complications after bariatric surgery have been understudied. This review assesses <30-d major complications associated with bariatric procedures, including anastomotic leak, myocardial infarction and pulmonary embolism. This review included 71 studies conducted in the USA between 2003 and 2014 and 107,874 patients undergoing either gastric bypass, adjustable gastric banding or sleeve gastrectomy, with mean age of 44 years and pre-surgery body mass index of 46.5 kg m-2 . Less than 30-d anastomotic leak rate was 1.15%; myocardial infarction rate was 0.37%; pulmonary embolism rate was 1.17%. Among all patients, mortality rate following anastomotic leak, myocardial infarction and pulmonary embolism was 0.12%, 0.37% and 0.18%, respectively. Among surgical procedures, <30-d after surgery, sleeve gastrectomy (1.21% [95% confidence interval, 0.23-2.19%]) had higher anastomotic leak rate than gastric bypass (1.14% [95% confidence interval, 0.84-1.43%]); gastric bypass had higher rates of myocardial infarction and pulmonary embolism than adjustable gastric banding or sleeve gastrectomy. During the review, we found that the quality of complication reporting is lower than the reporting of other outcomes. In summary, <30-d rates of the three major complications after either one of the procedures range from 0% to 1.55%. Mortality following these complications ranges from 0% to 0.64%. Future studies reporting complications after bariatric surgery should improve their reporting quality.

Perioperative risk and complications of revisional bariatric surgery compared to primary Roux-en-Y gastric bypass.

INTRODUCTION: Growing number of patients requires revisional bariatric surgery. This study compares perioperative course and outcomes of revisional versus primary bariatric surgery. METHODS: Patients who underwent revisional bariatric surgery from Jan 1997 to Sept 2012 were reviewed retrospectively. Every revisional patient with BMI >35 and age <70 was matched with a primary Roux-en-Y gastric bypass control patient based on preoperative BMI, age, sex, and year of surgery. Patients' preoperative indications, intraoperative/postoperative course, and complications were analyzed. RESULTS: Two hundred and fifty five patients underwent revisional bariatric surgery with resulting Roux-en-Y gastric bypass anatomy while 1,674 patients underwent primary gastric bypass in the same time interval. Of 255 patients, 172 patients were paired with 172 primary gastric bypass patients. Revisional bariatric group had preoperative BMI 48 ± 9, age 52 ± 9 years, 93 % female, 44 % laparoscopic, 30 % diabetic, 60 % hypertensive. Primary bypass patients had preoperative BMI 49 ± 8, age 52 ± 9 years, 93 % female, 97 % laparoscopic, 49 % diabetic, 67 % hypertensive. Compared to primary bypass patients, revisional patients had significantly higher estimated blood loss (463.7 vs. 113.3 mL), longer operative time (272.5 vs. 175.5 min), greater risk for ICU stay (N = 24, 14 % vs. N = 2, 1 %), and longer hospital stay (5.6 vs. 2.5 days). There were significantly more intraoperative liver (N = 13, 8 % vs. N = 1, 1 %) and spleen (N = 18, 10 % vs. N = 0) injuries, and more enterotomies (N = 9, 5 % vs. N = 0) in the revisional group. There were also significantly more postoperative complications (N = 94, 55 % vs. N = 48, 28 %), readmissions (N = 27, 16 % vs. N = 12, 7 %), and reoperations (N = 16, 9 % vs. N = 3, 2 %) within 30 days of surgery. Mean percentage weight loss at 1 year was significantly less for revisional patients (27 vs. 37 %). There was no significant difference in 30 day mortality between the two groups (N = 6 vs. 0). CONCLUSION: Even in experienced hands, complex revisional bariatric surgery should be approached with significant caution, especially given that weight loss is less substantial.

Decrease in hepatic very-low-density lipoprotein-triglyceride secretion after weight loss is inversely associated with changes in circulating leptin.

AIM: Although weight loss usually decreases very-low-density lipoprotein-triglyceride (VLDL-TG) secretion rate, the change in VLDL-TG kinetics is not directly related to the change in body weight. Circulating leptin also declines with weight loss and can affect hepatic lipid metabolism. The aim of this study was to determine whether circulating leptin is associated with weight loss-induced changes in VLDL-TG secretion. METHODS: Ten extremely obese subjects were studied. VLDL-TG secretion rate and the contribution of systemic (derived from lipolysis of subcutaneous adipose tissue TG) and non-systemic fatty acids (derived primarily from lipolysis of intrahepatic and intraperitoneal TG, and de novo lipogenesis) to VLDL-TG production were determined by using stable isotopically labelled tracer methods before and 1 year after gastric bypass surgery. RESULTS: Subjects lost 33 +/- 12% of body weight, and VLDL-TG secretion rate decreased by 46 +/- 23% (p = 0.001), primarily because of a decrease in the secretion of VLDL-TG from non-systemic fatty acids (p = 0.002). Changes in VLDL-TG secretion rates were not significantly related to reductions in body weight, body mass index, plasma palmitate flux, free fatty acid or insulin concentrations. The change in VLDL-TG secretion was inversely correlated with the change in plasma leptin concentration (r = -0.72, p = 0.013), because of a negative association between changes in leptin and VLDL-TG secretion from non-systemic fatty acids (r = -0.95, p < 0.001). CONCLUSIONS: Weight loss-induced changes in plasma leptin concentration are inversely associated with changes in VLDL-TG secretion rate. Additional studies are needed to determine whether the correlation between circulating leptin and VLDL-TG secretion represents a cause-and-effect relationship.

Esophageal manometric characteristics and outcomes for laparoscopic esophageal diverticulectomy, myotomy, and partial fundoplication for epiphrenic diverticula.

PURPOSE: The purpose of this study is to characterize the esophageal motor and lower esophageal sphincter (LES) abnormalities associated with epiphrenic esophageal diverticula and analyze outcomes for laparoscopic esophageal diverticulectomy, myotomy, and partial fundoplication. METHODS: The endoscopic, radiographic, manometric, and perioperative records for patients undergoing laparoscopic esophageal diverticulectomy, anterior esophageal myotomy, and partial fundoplication from 8/99 until 9/06 were reviewed from an Institutional Review Board (IRB)-approved outcomes database. Data are given as mean +/- standard deviation (SD). RESULTS: An esophageal body motor disorder and/or LES abnormalities were present in 11 patients with epiphrenic diverticula; three patients were characterized as achalasia, one had vigorous achalasia, two had diffuse esophageal spasm, and five had a nonspecific motor disorder. Presenting symptoms included dysphagia (13/13), regurgitation (7/13), and chest pain (4/13). Three patients had previous Botox injections and three patients had esophageal dilatations. Laparoscopic epiphrenic diverticulectomy with an anterior esophageal myotomy was completed in 13 patients (M:F; 3:10) with a mean age of 67.6 +/- 4.2 years, body mass index (BMI) of 28.1 +/- 1.9 kg/m2 and American Society of Anesthesiologists (ASA) 2.2 +/- 0.1. Partial fundoplication was performed in 12/13 patients (Dor, n = 2; Toupet, n = 10). Four patients had a type I and one patient had a type III hiatal hernia requiring repair. Mean operative time was 210 +/- 15.1 min and mean length of stay (LOS) was 2.8 +/- 0.4 days. Two grade II or higher complications occurred, including one patient who was readmitted on postoperative day 4 with a leak requiring a thoracotomy. After a mean follow-up of 13.6 +/- 3.0 months (range 3-36 months), two patients complained of mild solid food dysphagia and one patient required proton pump inhibitor (PPI) for gastroesophageal reflux disease (GERD) symptoms. CONCLUSION: The majority of patients with epiphrenic esophageal diverticula have esophageal body motor disorders and/or LES abnormalities. Laparoscopic esophageal diverticulectomy and anterior esophageal myotomy with partial fundoplication is an appropriate alternative with acceptable short-term outcomes in symptomatic patients.

Laparoscopic splenectomy for splenic masses.

BACKGROUND: This study aimed to evaluate the perioperative outcomes and pathology of patients undergoing laparoscopic splenectomy for splenic masses. METHODS: The records for 174 patients who underwent laparoscopic splenectomy from May 1994 to August 2006 were reviewed. Patient demographics, preoperative imaging, American Society of Anesthesiologists (ASA) score, body mass index (BMI), estimated blood loss (EBL), operative time, spleen size, complications, hospital length of stay (LOS), pathology, and mortality were extracted from the records. Data are expressed as means +/- standard deviation. Statistical significance (p < 0.05) was determined using a two-tailed t-test and Fisher's exact test. RESULTS: A splenic mass was diagnosed preoperatively for 18 patients (10.3%) (7 males and 11 females). The mean patient age was 51.4 +/- 13.7 years. The mean ASA was 2.3 +/- 0.8, and the mean BMI was 27.3 +/- 5.8 kg/m(2). Computed tomography scans demonstrated splenic masses in all the patients. The mean mass size was 4.3 +/- 3.3 cm (range, 1.0-11.0 cm), and the mean spleen length was 14.6 +/- 7.5 cm (range, 5.5-40.2 cm). Total laparoscopic splenectomy was completed for 15 patients, and hand-assisted splenectomy was performed for 3 patients (2 converted). The mean operative time was 128.3 +/- 38.5 min, and the mean EBL was 110 +/- 137.5 ml. There were no intraoperative complications or 30-day mortalities. The postoperative complication rate was 11.1%, and the mean LOS was 1.9 +/- 1.0 days. The pathology for six patients (33.3%) was malignant (5 lymphomas and 1 adenocarcinoma). There were three false-positive positron emission tomography (PET) scans. Compared with 73 patients undergoing laparoscopic splenectomy for idiopathic thrombocytopenic purpura, there was no significant difference in mean EBL, operative time, conversion rate, complication rate, LOS, or 30-day mortality rate (p > 0.05). CONCLUSIONS: Laparoscopic splenectomy is appropriate for patients whose indication for surgery is splenic mass. Suspicious splenic masses should be removed due to the relatively high incidence of malignant pathology, most commonly lymphoma.

Outcomes analysis of laparoscopic resection of pancreatic neoplasms.

BACKGROUND: Experience with laparoscopic resection of pancreatic neoplasms remains limited. The purpose of this study is to critically analyze the indications for and outcomes after laparoscopic resection of pancreatic neoplasms. METHODS: The medical records of all patients undergoing laparoscopic resection of pancreatic neoplasms from July 2000 to February 2006 were reviewed. Data are expressed as mean +/- standard deviation. RESULTS: Laparoscopic pancreatic resection was performed in 22 patients (M:F, 8:14) with a mean age of 56.3 +/- 15.1 years and mean body mass index (BMI) of 26.3 +/- 4.5 kg/m2. Nine patients had undergone previous intra-abdominal surgery. Indications for pancreatic resection were cyst (1), glucagonoma (1), gastrinoma (2), insulinoma (3), metastatic tumor (2), IPMT (4), nonfunctioning neuroendocrine tumor (3), and mucinous/serous cystadenoma (6). Mean tumor size was 2.4 +/- 1.6 cm. Laparoscopic distal pancreatectomy was attempted in 18 patients and completed in 17, and enucleation was performed in 4 patients. Laparoscopic ultrasound (n = 10) and a hand-assisted technique (n = 4) were utilized selectively. Mean operative time was 236 +/- 60 min and mean blood loss was 244 +/- 516 ml. There was one conversion to an open procedure because of bleeding from the splenic vein. The mean postoperative LOS was 4.5 +/- 2.0 days. Seven patients experienced a total of ten postoperative complications, including a urinary tract infection (UTI) (1), lower-extremity deep venous thrombosis (DVT) and pulmonary embolus (1), infected peripancreatic fluid collection (1), pancreatic pseudocyst (1), and pancreatic fistula (6). Five pancreatic fistulas were managed by percutaneous drainage. The reoperation rate was 4.5% and the overall pancreatic-related complication rate was 36.4%. One patient developed pancreatitis and a pseudocyst 5 months postoperatively, which was managed successfully with a pancreatic duct stent. There was no 30-day mortality. CONCLUSIONS: Laparoscopic pancreatic resection is safe and feasible in selected patients with pancreatic neoplasms. With a pancreatic duct leak rate of 27%, this problem remains an area of development for the minimally invasive technique.

Experience with laparoscopic gastric resection: results and outcomes for 37 cases.

BACKGROUND: This study aimed to review the authors' technique, results, and outcomes for laparoscopic gastric wedge and segmental resections in patients with benign gastric diseases. METHODS: A retrospective clinical chart review was performed for all the patients who underwent laparoscopic gastric resection at the Washington University Medical Center from 1997 through March 2004. The surgical approach, operative results, complications, and subsequent clinical course were analyzed. Data are expressed as mean +/- standard deviation. RESULTS: Laparoscopic gastric resection was attempted in 37 cases involving 21 women and 16 men with a mean age of 61 +/- 13 years. The indications for surgery included suspected gastric stromal tumor (GIST) or carcinoid (n = 22), other benign gastric lesions (n = 6), benign gastric outlet obstruction (n = 4), and nonhealing peptic ulcer (n = 5). Segmental resection using gastroenteric anastomosis, with or without vagotomy, was performed in 14 patients, wedge resection in 22 patients, and laparoscopic enucleation in 1 patient. Resection was totally laparoscopic in 25 cases and laparoscopically assisted (with an accessory incision) in 12 cases. The mean operative time was 165 +/- 58 min, and the blood loss was 84 +/- 77 ml. Two patients (5.4%) underwent conversion to open resection. Intraoperative gastroscopy was performed in 16 cases (44%) as an aid to the resection. Regular diet was resumed at a mean of 3.0 +/- 1.7 days, and the mean length of hospital stay was 3.9 +/- 2.1 days. Four patients (10.8%) experienced major complications including subphrenic abscess (n = 1), pneumonia with respiratory failure (n = 1), splenic vein injury requiring splenectomy (n = 1), and gastric outlet obstruction (n = 1) that required reoperation 1 year later. Minor complications included intraabdominal fluid collection (n = 1), postoperative gastroparesis (n = 1), urinary retention (n = 1), and incisional hernia (n = 1). CONCLUSIONS: Laparoscopic gastric resections can be performed safely in patients with a variety of benign gastric disorders. The use of an accessory incision for reanastomosis and specimen extraction facilitates the procedure in difficult cases.

Department of Veterans Affairs, University of Utah consortium participation in the NLM/AHCPR Large Scale Vocabulary Test.

The Large Scale Vocabulary Test (LSVT) was designed to evaluate how well the Metathesaurus plus planned additions to Meta covered the documentation needs of clinicians. Our consortium collected 10,538 clinical narratives from patient problem lists recorded at 65 Veterans Hospitals, internal medicine ambulatory care practices, diagnostic history and physical examination data elements from Iliad, and nursing shift notes and emergency transport patient records. The results showed 94% of submitted terms resulted in acceptable matches. 49% of submitted terms were judged to be synonymous with the match terms, 35% were judged to be more specific (usually due to modifiers), 2%, were less specific, and 6% had an associative relationship. In 8% of cases either no match was found by the LSVT interface or all proposed matches were rejected by the raters. The LSVT content was quite suitable for coding our narratives. Necessary improvements for an electronic record would include the ability to compose modifiers together with root concepts.

Inter-rater reliability and review of the VA unresolved narratives.

To better understand how VA clinicians use medical vocabulary in every day practice, we set out to characterize terms generated in the Problem List module of the VA's DHCP system that were not mapped to terms in the controlled-vocabulary lexicon of DHCP. When entered terms fail to match those in the lexicon, a note is sent to a central repository. When our study started, the volume in that repository had reached 16,783 terms. We wished to characterize the potential reasons why these terms failed to match terms in the lexicon. After examining two small samples of randomly selected terms, we used group consensus to develop a set of rating criteria and a rating form. To be sure that the results of multiple reviewers could be confidently compared, we analyzed the inter-rater agreement of our rating process. Two rates used this form to rate the same 400 terms. We found that modifiers and numeric data were common and consistent reasons for failure to match, while others such as use of synonyms and absence of the concept from the lexicon were common but less consistently selected.

Ectopic jejunal pacemakers after jejunal transection and their relationship to transit.

The hypothesis was that orally moving pacesetter potentials distal to a site of jejunal transection and anastomosis would slow transit through jejunum containing them and that reoperation with excision of bowel containing these pacesetter potentials would restore transit to the control. In six conscious dogs with jejunal serosal electrodes for recording myoelectric activity and a jejunal perfusion/aspiration catheter for measuring transit, jejunal pacesetter potential frequency decreased distal to a midjejunal transection and anastomosis from 18.7 +/- 0.3 (SE) cycles/min (cpm) proximal to the site to 14.4 +/- 0.6 cpm distal to the site (P < 0.05). In addition, orally propagating pacesetter potentials occurred > 25% of the time in a 37 +/- 7 cm length of bowel distal to the site during fasting and after feeding. Transit through the segment with the orally moving pacesetter potentials was slowed during feeding (half time before and after transection, 7.7 +/- 1.1 and 13 +/- 2.0 min, respectively, P < 0.05). Resection of the segment with the abnormal pacesetter potentials shortened the length of bowel containing them to 24 +/- 2 cm (P > 0.05) and restored transit to the control. In conclusion, orally moving pacesetter potentials distal to a canine jejunal transection and anastomosis slowed transit through the segment of bowel containing them. Resection of the segment restored transit to the control.

Effect of electrical stimulation on gastric electrical activity, motility and emptying.

The aim was to measure the effect of gastric electrical stimulation on the frequency of canine antral pacesetter potentials (PPs), the strength of antral contractions, and the rate of gastric emptying while fasting, after feeding and with pentagastrin stimulation. Four conscious dogs with a stimulating electrode placed 10 cm proximal to the pylorus and recording electrodes and strain gauges placed 7, 5 and 3 cm proximal to the pylorus underwent myoelectric and strain gauge recordings while fasting, after feeding (250 ml 5% dextrose labelled with polyethylene glycol), and during pentagastrin infusion (0.5 micrograms kg-1 min-1) on four separate days. On each day, electrical stimulation was done using one of four stimulation frequencies (0, 6, 30 and 1200 stimuli per minute [s.p.m.]). Stimulation at 6 and 30 s.p.m. increased the fasting and fed PP frequency, whereas 1200 s.p.m. stimulation did not. Feeding decreased the maximum driven frequency, and pentagastrin increased it. Neither the motility index nor the gastric emptying rate were consistently changed by stimulation at any frequency. In conclusion, canine proximal antral stimulation at 6 and 30 s.p.m. sped PP frequency during fasting and after feeding, but stimulation over a wide range of frequencies had little effect on gastric contractions and emptying.

Gastrointestinal peptide hormones during postoperative ileus. Effect of octreotide.

The hypothesis was that postoperative ileus might be caused by a disturbed balance between the motor-stimulating hormones, motilin and substance P, and the motor-inhibitory hormone, vasoactive intestinal polypeptide, and that octreotide might prevent this disturbance and so ameliorate the ileus. In 15 conscious dogs with chronic gastrointestinal electrodes, electrical activity was recorded and blood was drawn for radioimmunoassay of motilin, substance P, and vasoactive intestinal peptide (VIP) during fasting and after a liquid meal. Ileus was then induced by celiotomy and intestinal abrasion. During and after operation, five dogs received 154 mM NaCl only, five dogs octreotide, 0.19 micrograms/kg/hr, and five octreotide, 0.83 micrograms/kg/hr. Plasma levels of motilin, substance P, and VIP were changed little by operation, but cyclical increases in plasma motilin, which occurred preoperatively during phase III of the interdigestive myoelectric complex, were completely abolished postoperatively during ileus, as was the complex itself. Octreotide ameliorated the ileus and restored the cyclic increases in motilin found in health, nor did it alter plasma substance P and VIP. In conclusion, octreotide ameliorates postoperative ileus, but it does not do so by increasing plasma motilin or substance P or decreasing plasma VIP.

Gastrointestinal pacing.

Gastrointestinal pacing has been used to alter motor function and is effective in animal models in modulating gastric emptying, intestinal transit, and absorption. Application of gastrointestinal pacing to disorders of the human stomach and small bowel is an attractive treatment option that may some day become a clinical reality. Several technical problems must be overcome before further clinical testing can proceed.

Effects of gastric pacing on canine gastric motility and emptying.

Gastric pacing has been achieved in dogs and humans, but its effects on gastric motility and emptying have not been thoroughly explored. Seven dogs had bipolar electrodes placed 1 and 10 cm proximal to the pylorus for reverse and forward pacing and monopolar recording electrodes and strain gauges placed 3, 5, and 7 cm proximal to the pylorus. After recovery, myoelectrical and contractile activity and gastric emptying of a mixed meal (50 g 99mTc-labeled liver and 250 ml 111In-labeled 5% dextrose broth solution) were measured in each of three conditions: no pacing, reverse pacing, and forward pacing (frequency 0.5 cycles/min above intrinsic pacesetter potential frequency). Reverse pacing reversed the direction of > 90% of antral pacesetter potentials and peristaltic waves in six of seven dogs, prolonged the lag phase of solid emptying, prolonged the half emptying time of solids and liquids, and increased the antral motility index. Forward pacing entrained pacesetter potentials but had no consistent effect on emptying or antral contractions. In conclusion, reverse gastric pacing slows gastric emptying of digestible solids and liquids by reversing the direction of antral peristalsis and increasing the antral motility index, whereas forward pacing has no such effects.

Treatment of acute postoperative ileus with octreotide.

Our hypothesis was that postoperative ileus is caused by the release of neurotransmitters in the gut wall that inhibit motility. We reasoned that blocking the release with octreotide would prevent ileus. We placed serosal electrodes on the small intestine and stomachs of 15 dogs and inserted a duodenal cannula. After the animals recovered, electrical activity was recorded, and small bowel transit, colonic transit, and gastric emptying were studied radiographically and scintigraphically. Ileus was induced by celiotomy and intestinal abrasion. Dogs were randomized to receive on postoperative days 0 through 3 either a placebo (n = 5), octreotide, 1.5 micrograms/kg/8 hr subcutaneously (n = 5), or octreotide 0.83 micrograms/kg/hr intravenously (n = 5). Both doses of octreotide resulted in a faster return to preoperative values of small bowel interdigestive myoelectric activity and transit and colonic transit than did the placebo. The larger dose of octreotide, however, slowed gastric emptying. In conclusion, octreotide shortened the duration of postoperative ileus in the small bowel and colon of dogs.

Postgastrectomy syndromes.

Anatomic and physiological changes introduced by gastric surgery result in postgastrectomy syndromes in approximately 20% of patients. Most of these disorders are caused by operation-induced abnormalities in the motor functions of the stomach, including disturbances in the gastric reservoir function, the mechanical-digestive function, and the transporting function. Division of the vagal innervation to the stomach and ablation or bypass of the pylorus are the most significant factors contributing to postgastrectomy syndromes. Either rapid or slow emptying may result, depending on the relative importance of lack of a compliant gastric reservoir, loss of an effective contractile force, and loss of controlling factors that slow or speed gastric emptying and result in duodenal-gastric reflux. Clearly defining which syndrome is present in a given patient is critical to developing a rational treatment plan. In syndromes with slow gastric emptying, bilious vomiting, or alkaline reflux gastritis, the use of endoscopy is essential to rule out mechanical causes of the syndrome. Contrast radiography and scintigraphic gastric emptying studies are useful to document rapid or delayed gastric emptying. Postgastrectomy syndromes often abate with time. Conservative measures, including medical, dietary, and behavioral therapy, should be given at least a 1-year trial. If these nonoperative measures fail, surgical therapy is recommended. The Roux-en-Y gastrojejunostomy is useful for patients with dumping, because it slows gastric emptying and the transit of chyme through the Roux limb. The same operation helps patients with alkaline reflux gastritis, because it diverts pancreaticobiliary secretions away from the gastric remnant. Near-total gastrectomy, which reduces the size of a flaccid gastric reservoir, can be used to treat delayed gastric emptying. This operation should be combined with the Roux procedure to prevent postoperative reflux gastritis and esophagitis. Newer techniques, such as gastrointestinal pacing and the uncut Roux operation, may improve the treatment of the postgastrectomy syndromes in the future.

Proton magnetic resonance imaging of the ocular lens.

Several osmotic cataract models as well as human diabetic lenses were tested by nuclear magnetic resonance spectroscopy and imaging. Both longitudinal (T1) and transverse (T2) relaxation times increased with increase in lens hydration. Therefore proton magnetic resonance imaging (MRI) can be used to detect changes of the biophysical environment of water proton in the lens. T2-weighted imaging sequence (spin-echo) can be used to differentiate lenses with hydrational changes since they exhibit higher signal intensity (because of long T2) than normal lenses at the same TE (echo time). A greater contrast can be achieved with the inversion-recovery sequence, which, in addition to contribution from T2, also incorporates T1 and proton density terms. Proton MRI is potentially useful for the detection of pre-cataractous changes.

Cimetidine modulates natural killer cell function of patients with chronic lymphocytic leukemia.

Peripheral blood natural killer (NK) activity in patients with B-cell chronic lymphocytic leukemia (B-CLL) is frequently low or absent. Because cimetidine (a histamine-2 antagonist) has been shown to alter human lymphocyte function in vitro, we decided to study cimetidine's effect on peripheral blood NK activity of patients with B-CLL and controls. We administered cimetidine orally (1.2 gm per day) to seven patients with B-CLL and 12 controls for up to 28 days. Peripheral blood NK activity of patients with B-CLL rose from a pretreatment level of 0.7 +/- 0.5 (mean +/- SEM) lytic units/10(6) cells (LU) to 8.7 +/- 2.4 LU (P less than 0.05) at day 28. Peripheral blood NK activity of controls decreased after 14 days of cimetidine treatment but returned to pretreatment levels by day 28. When peripheral blood cells from controls were exposed to cimetidine during in vitro incubation (10 micrograms/ml), mean NK activity was increased at 48 hours (54% +/- 22% increase over controls, n = 5, P less than 0.05). Single cell cytotoxicity assays revealed increased killing of target cells (but not effector-target conjugation) with cimetidine-exposed effector cells. These data suggest that cimetidine may be useful to augment peripheral blood NK activity for patients with B-CLL.