A Prospective Evaluation of Intracorporeal Laparoscopic Small Bowel Anastomosis during Gastric Bypass

BACKGROUND

We evaluated the safety and feasibility of performing a laparoscopic intracorporeal end-to-side small bowel anastomosis using a stapling technique as part of a Roux-en-Y gastric bypass operation (RYGBP).

METHODS

80 consecutive patients who underwent RYGBP with laparoscopic jejunojejunostomy were evaluated. Operative time and intraoperative and postoperative complications directly related to the jejunojejunostomy anastomosis were recorded.

RESULTS

All 80 laparoscopic jejunojejunostomy procedures were successfully performed without conversion to laparotomy. Mean operative time was longer for the first 40 laparoscopic RYGBP than for the last 40 RYGBP (32+/-18 min vs 21+/-14 min, respectively, p<0.05). Intraoperative complications were staple-line bleeding (2 patients) and narrowing of the anastomosis (1 patient). Postoperative complications were four small bowel obstructions: technical narrowing at jejunojejunostomy site (2 patients), angulation of the afferent limb (1 patient), and food impaction at the jejunojejunostomy anastomosis (1 patient). These four patients underwent successful laparoscopic re-exploration and creation of another jejunojejunostomy proximal to the original anastomosis. There were no small bowel anastomotic leaks. The median time to resuming oral diet was 2 days.

CONCLUSIONS

Laparoscopic jejunojejunostomy as part of the RYGBP operation is a safe and technically feasible procedure. Postoperative small bowel obstruction is a potential complication, which can be prevented by avoiding technical narrowing of the afferent limb.

Comparison of pulmonary function and postoperative pain after laparoscopic versus open gastric bypass: a randomized trial

BACKGROUND

Impairment of pulmonary function is common after upper abdominal operations. The purpose of this study was to compare postoperative pulmonary function and analgesic requirements in patients undergoing either laparoscopic or open Roux-en-Y gastric bypass (GBP).

STUDY DESIGN

Seventy patients with a body mass index of 40 to 60 kg/m2 were randomly assigned to undergo laparoscopic (n = 36) or open (n = 34) GBP. The two groups were similar in age, gender, body mass index, pulmonary history, and baseline pulmonary function. Pulmonary function studies were performed preoperatively and on postoperative days 1, 2, 3, and 7. Oxygen saturation and chest radiographs were performed on both groups preoperatively and on postoperative day 1. Postoperative pain was evaluated using a visual analog scale and the amount of narcotic consumed was recorded. Data are presented as mean +/- standard deviation.

RESULTS

Laparoscopic GBP patients had significantly less impairment of pulmonary function than open GBP patients on the first three postoperative days (p < 0.05). By the 7th postoperative day, all pulmonary function parameters in the laparoscopic GBP group had returned to within preoperative levels, but only one parameter (peak expiratory flow) had returned to preoperative levels in the open GBP group. On the first postoperative day, laparoscopic GBP patients used less morphine than open GBP patients (46 +/- 31 mg versus 76 +/- 39 mg, respectively, p < 0.001), and visual analog scale pain scores at rest and during mobilization were lower after laparoscopic GBP than after open GBP (p < 0.05). Fewer patients after laparoscopic GBP than after open GBP developed hypoxemia (31% versus 76%, p < 0.001) and segmental atelectasis (6% versus 55%, p = 0.003).

CONCLUSION

Laparoscopic gastric bypass resulted in less postoperative suppression of pulmonary function, decreased pain, improved oxygenation, and less atelectasis than open gastric bypass.

Up-regulation of vascular endothelial growth factor in breast cancer cells by the heregulin-beta1-activated p38 signaling pathway enhances endothelial cell migration

Heregulin (HRG) belongs to a family of polypeptide growth factors that bind to receptor tyrosine kinases ErbB3 and ErbB4. HRG binding induces ErbB3 and ErbB4 heterodimerization with ErbB2, activating downstream signal transduction. Vascular endothelial growth factor (VEGF) is a primary regulator of physiological angiogenesis and is a major mediator of pathological angiogenesis, such as tumor-associated neovascularization. In this study, we demonstrate that HRG-beta1 increased secretion of VEGF from breast cancer cells in a time- and dosage-dependent manner and that this increase resulted from up-regulation of VEGF mRNA expression via transcriptional activation of the VEGF promoter. Deletion and mutational analysis revealed that a CA-rich upstream HRG response element located between nucleotide-2249 and -2242 in the VEGF promoter mediated HRG-induced transcriptional up-regulation of VEGF. While investigating the downstream signaling pathways involved in HRG-mediated up-regulation of VEGF, we found that HRG activated extracellular signal-regulated protein kinases, Akt kinase, and p38 mitogen-activated protein kinase (MAPK). However, only the specific inhibitor of p38 MAPK (SB203580), not extracellular signal-regulated kinase inhibitor PD98059 nor the inhibitor of phosphatidylinositol 3-kinase-Akt pathway (Wortmannin), blocked the up-regulation of VEGF by HRG. The HRG-stimulated secretion of VEGF from breast cancer cells resulted in increased migration of murine lung endothelial cells, an activity that was inhibited by either VEGF-neutralizing antibody or SB203580. These results show that HRG can activate p38 MAPK to enhance VEGF transcription via an upstream HRG response element, leading to increased VEGF secretion and angiogenic response in breast cancer cells.

Minimally invasive esophagectomy

BACKGROUND

Open esophagectomy can be associated with significant morbidity and delay return to routine activities. Minimally invasive surgery may lower the morbidity of esophagectomy but only a few small series have been published.

METHODS

From August 1996 to September 1999, 77 patients underwent minimally invasive esophagectomy. Initially, esophagectomy was approached totally laparoscopically or with mini-thoracotomy; thoracoscopy subsequently replaced thoracotomy.

RESULTS

Indications included esophageal carcinoma (n = 54), Barrett's high-grade dysplasia or carcinoma in situ (n = 17), and benign miscellaneous (n = 6). There were 50 men and 27 women with an average age of 66 years (range 30 to 94 years). Median operative time was 7.5 hours (4.5 hours with > 20 case experience). Median intensive care unit stay was 1 day (range 0 to 60 days); median length of stay was 7 days (range 4 to 73 days) with no operative or hospital mortalities. There were four nonemergent conversions to open esophagectomy; major and minor complication rates were 27% and 55%, respectively.

CONCLUSIONS

Minimally invasive esophagectomy is technically feasible and safe in our center, which has extensive minimally invasive and open esophageal experience. Open surgery should remain the standard until future studies conclusively demonstrate advantages of minimally invasive approaches.

Laparoscopic suturing evaluation among surgical residents

BACKGROUND

Laparoscopic suturing is an integral part of advanced laparoscopic surgery training. The objective of this study was to evaluate the performance and preference of surgical residents performing intracorporeal and extracorporeal knot-tying techniques using conventional and Endo Stitch instruments. The residents were also evaluated on their suturing techniques using conventional instruments, the Endo Stitch, and the Suture Assistant.

METHODS

Using an inanimate laparoscopic trainer model, 39 residents were evaluated as they performed laparoscopic knot tying exercises. Endpoints of the study were execution time and subjective preference of surgical residents with respect to the type of instrument used for knot tying. Forty-three residents were evaluated as they performed laparoscopic suturing exercises with three different types of suturing instruments using the same endpoints.

RESULTS

The intracorporeal technique was the preferred (89%) method of knot tying among surgical residents. The time for completion of laparoscopic suturing was significantly (P < 0.05) shorter with the Endo Stitch (114 +/- 64 s) than with the conventional instrument (206 +/- 107 s) or the Suture Assistant (151 +/- 70 s). Residents preferred the use of the Endo Stitch in all three categories for suturing, knot tying, and handling.

CONCLUSION

The Endo Stitch enhanced laparoscopic skills and was the preferred instrument for laparoscopic knot tying and suturing among surgical residents.

Comparison of minimally invasive esophagectomy with transthoracic and transhiatal esophagectomy

HYPOTHESIS

Minimally invasive esophagectomy can be performed as safely as conventional esophagectomy and has distinct perioperative outcome advantages.

DESIGN

A retrospective comparison of 3 methods of esophagectomy: minimally invasive, transthoracic, and blunt transhiatal.

SETTING

University medical center.

PATIENTS

Eighteen consecutive patients underwent combined thoracoscopic and laparoscopic esophagectomy from October 9, 1998, through January 19, 2000. These patients were compared with 16 patients who underwent transthoracic esophagectomy and 20 patients who underwent blunt transhiatal esophagectomy from June 1, 1993, through August 5, 1998.

MAIN OUTCOME MEASURES

Operative time, amount of blood loss, number of operative transfusions, length of intensive care and hospital stays, complications, and mortality.

RESULTS

Patients who had minimally invasive esophagectomy had shorter operative times, less blood loss, fewer transfusions, and shortened intensive care unit and hospital courses than patients who underwent transthoracic or blunt transhiatal esophagectomy. There was no significant difference in the incidence of anastomotic leak or respiratory complications among the 3 groups.

CONCLUSION

Minimally invasive esophagectomy is safe and provides clinical advantages compared with transthoracic and blunt transhiatal esophagectomy.

Minimally invasive surgical staging for esophageal cancer

BACKGROUND

The incidence of esophageal adenocarcinoma is increasing in the United States, and the 5-year survival rate is dismal. Preliminary data suggest that conventional imaging is inaccurate in staging esophageal cancer and could limit accurate assessment of new treatments. The objective of this study was to compare minimally invasive surgical staging (MIS) with conventional imaging for staging esophageal cancer.

METHODS

Patients with potentially resectable esophageal cancer were eligible. Staging by conventional methods used computed tomography (CT) scan of the chest and abdomen, and endoscopic ultrasound (EUS), whereas MIS used laparoscopy and videothoracoscopy. Conventional staging results were compared to those from MIS.

RESULTS

In 53 patients, the following stages were assigned by CT scan and EUS: carcinoma in situ (CIS; n = 1), I (n = 1), II (n = 23), III (n = 20), IV (n = 8). In 17 patients (32.1%), MIS demonstrated inaccuracies in the conventional imaging, reassigning a lower stage in 10 patients and a more advanced stage in 7 patients.

CONCLUSIONS

In 32.1% of patients with esophageal cancer, MIS changed the stage originally assigned by CT scan and EUS. Therefore, MIS should be applied to evaluate the accuracy of new noninvasive imaging methods and to assess new therapies for esophageal cancer.

A comparison study of laparoscopic versus open gastric bypass for morbid obesity

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (GBP) has been previously described, but a comparative study between laparoscopic and open GBP has not been reported. The purpose of this study was to compare surgical outcomes oflaparoscopic GBP with those of open GBP for treatment of morbid obesity.

STUDY DESIGN

From August 1998 to September 1999, we prospectively collected outcome data on 35 patients with body-mass indices between 40 kg/m2 and 60 kg/m2 who underwent laparoscopic GBP. Demographics, operative data, perioperative complications, and weight losses were collected and compared with those obtained from a retrospective chart review of 35 patients with body-mass indices between 40 kg/m2 and 60 kg/m2 who underwent open GBP before August 1998.

RESULTS

Age, gender, preoperative body-mass index, preoperative comorbidity, and earlier abdominal surgery were similar in both groups. All laparoscopic operations were completed without conversion to laparotomy. Mean operative time, operative blood loss, length of intensive care stay, and length of hospital stay were significantly less after laparoscopic GBP than after open GBP (p<0.05). There was no 30-day mortality in either group. At 1-year followup, analysis of the percentage of excess body weight loss showed no significant difference between the two groups (p<0.05).

CONCLUSIONS

Laparoscopic Roux-en-Y gastric bypass is technically feasible and safe. Laparoscopic GBP confers the clinical benefits of laparoscopy and an initial weight loss similar to that of open GBP.

Contrastive prevalence of feline retrovirus infections between northern and southern Vietnam

The prevalence of infections with three feline retroviruses; feline leukemia virus (FeLV), feline immunodeficiency virus (FIV) and feline foamy virus (FeFV), was examined in domestic cats (Felis catus) and leopard cats (Felis bengalensis) in southern Vietnam in 1998. We then compared this data with our previous study in northern Vietnam in 1997. None of the cats had FeLV antigens in both the northern and southern areas. In contrast, there is a great distinction in the seropositivity of FIV. Twenty-two percent of domestic cats had FIV antibodies whereas no FIV positive cats were detected in northern area. FIV may have entered southern Vietnam recently and spread rapidly. FeFV infections were found in both areas, suggesting that FeFV might be present in the cat populations in Vietnam from the earliest time.

Endoscopic photodynamic therapy for obstructing esophageal cancer: 77 cases over a 2-year period

BACKGROUND

Photodynamic therapy (PDT) is an alternative treatment option for the palliation of obstructive esophageal cancer. We report our experience with PDT for patients presenting with inoperable, obstructing, or bleeding esophageal cancer.

METHODS

Seventy-seven patients with inoperable, obstructing esophageal cancer were treated with PDT from November 1996 to July 1998. Photofrin (1.5-2.0 mg/kg) was administered, followed by endoscopic light treatment (630 nm red dye laser) at 48 h. Dysphagia score (1 for no dysphagia to 5 for complete obstruction), dysphagia-free interval, and patient survival were assessed.

RESULTS

Seventy-seven patients underwent 125 PDT courses. The mean dysphagia score at 4 weeks after PDT in 90.8% of the patients improved from 3.2 +/- 0.7 to 1.9 +/- 0.8 (p < 0.05). PDT adequately controlled bleeding in all six patients who had bleeding. The most common complications after the 125 PDT courses were esophageal stricture (4.8%), Candida esophagitis (3.2%), symptomatic pleural effusion (3.2%), and sunburn (10.0%). Twenty-nine patients (38%) required more than one PDT course, and seven patients required placement of an expandable metal stent for recurrent dysphagia. The mean dysphagia-free interval was 80.3 +/- 58.2 days. The median survival was 5.9 months.

CONCLUSIONS

Photodynamic therapy is a safe and effective treatment for the palliation of obstructing and bleeding esophagus cancer.

Laparoscopy or thoracoscopy for achalasia

Achalasia is an esophageal motor disorder of unknown etiology. Typical manometric findings include aperistalsis of the esophageal body coupled with elevated pressure and incomplete relaxation of the lower esophageal sphincter during swallowing. Medical treatments consist of pneumatic dilatation or injections of botulinum toxin. Surgical treatment consists of Heller's myotomy with or without an antireflux procedure. Relief of dysphagia symptoms can be achieved in 85% to 94% of patients undergoing surgical treatment. In the past decade, the minimally invasive approach for the treatment of achalasia has been proven feasible, safe, and effective. We review the role of thoracoscopy and laparoscopy and address controversies in the management of patients with achalasia.

Thoracoscopic enucleation of an esophageal leiomyoma

A series of reports in the literature suggest that video assisted thoracoscopic resection of an esophageal leiomyoma offers distinct advantage over open approach. We describe a patient with esophageal leiomyoma who underwent surgical resection via thoracoscopic approach using four thoracic trocars. The postoperative period was uneventful and the patient was discharged on postoperative day 3.

Laparoscopic umbilical herniorrhaphy

BACKGROUND

Laparoscopic technique is an alternative approach to ventral hernia repair. This study evaluated the feasibility of performing umbilical hernia repair using a single 5-mm trocar technique.

PATIENTS AND METHODS

During February 1999 to November 1999, we performed laparoscopic umbilical hernia repair in 16 consecutive patients. All operations were performed under general anesthesia. One 5-mm port was used to visualize the defect. A second 5-mm port was inserted only if there was incarcerated omentum requiring reduction. The Endo Close was inserted through a 2-mm incision made directly over the hernia to perform transabdominal closure of the defect using nonabsorbable suture.

RESULTS

The mean size of the umbilical hernia defects was 1.2 cm +/- 0.4 (range 1.0-2.0 cm). All operations were completed laparoscopically with no intraoperative or postoperative complications. The mean operative time was 35 +/- 15 minutes (range 21-75 min). All cases were performed in an outpatient setting. There have been no recurrences at a mean follow-up of 5.9 months.

CONCLUSIONS

Laparoscopic umbilical herniorrhaphy is safe and technically feasible. Its potential advantages, such as a lower rate of recurrence, will need to be validated with longer follow-up.

Subsite mapping of the human pancreatic alpha-amylase active site through structural, kinetic, and mutagenesis techniques

We report a multifaceted study of the active site region of human pancreatic alpha-amylase. Through a series of novel kinetic analyses using malto-oligosaccharides and malto-oligosaccharyl fluorides, an overall cleavage action pattern for this enzyme has been developed. The preferred binding/cleavage mode occurs when a maltose residue serves as the leaving group (aglycone sites +1 and +2) and there are three sugars in the glycon (-1, -2, -3) sites. Overall it appears that five binding subsites span the active site, although an additional glycon subsite appears to be a significant factor in the binding of longer substrates. Kinetic parameters for the cleavage of substrates modified at the 2 and 4' ' positions also highlight the importance of these hydroxyl groups for catalysis and identify the rate-determining step. Further kinetic and structural studies pinpoint Asp197 as being the likely nucleophile in catalysis, with substitution of this residue leading to an approximately 10(6)-fold drop in catalytic activity. Structural studies show that the original pseudo-tetrasaccharide structure of acarbose is modified upon binding, presumably through a series of hydrolysis and transglycosylation reactions. The end result is a pseudo-pentasaccharide moiety that spans the active site region with its N-linked "glycosidic" bond positioned at the normal site of cleavage. Interestingly, the side chains of Glu233 and Asp300, along with a water molecule, are aligned about the inhibitor N-linked glycosidic bond in a manner suggesting that these might act individually or collectively in the role of acid/base catalyst in the reaction mechanism. Indeed, kinetic analyses show that substitution of the side chains of either Glu233 or Asp300 leads to as much as a approximately 10(3)-fold decrease in catalytic activity. Structural analyses of the Asp300Asn variant of human pancreatic alpha-amylase and its complex with acarbose clearly demonstrate the importance of Asp300 to the mode of inhibitor binding.

Minimally invasive esophagectomy for Barrett's esophagus with high-grade dysplasia

BACKGROUND

Barrett's esophagus with high-grade dysplasia (BE/HGD) is associated with invasive carcinoma in 30% to 70% of cases. Esophagectomy is the treatment of choice for patients with BE/HGD but esophagectomy can be associated with high morbidity and mortality. The aim of our study was to report our preliminary experience in applying minimally invasive surgical techniques to esophagectomy for BE/HGD.

METHODS

From August 1996 to February 1999, 12 consecutive patients underwent minimally invasive esophagectomy for biopsy-proven BE/HGD. Our consort consisted of 7 men and 5 women; average age was 64 years (range, 40-78 years). All patients underwent a complete laparoscopic or combined laparoscopic and thoracoscopic resection of the esophagus with cervical anastomosis.

RESULTS

Mean operative time was 7.8 +/- 2.1 hours, mean intensive care unit stay was 2.6 +/- 2.2 days, and mean length of hospital stay was 8.3 +/- 4.7 days. Five patients (42%) had carcinoma in situ or carcinoma identified on pathologic specimen. Analyses of all resected lymph nodes in the 12 patients were negative for metastatic disease. There were 6 major complications in 5 patients: 1 patient had a small bowel perforation requiring operative repair, 2 patients needed prolonged ventilatory support for respiratory insufficiency, and 3 patients had delayed gastric emptying requiring revision of the pyloromyotomy. The single minor complication in this series was a jejunostomy tube-site infection. There were no conversions to laparotomy or thoracotomy. All patients were alive and free of metastatic disease at a mean follow-up of 12.6 months.

CONCLUSIONS

Minimally invasive esophagectomy is a feasible and safe alternative to conventional open esophagectomy for patients with BE/HGD.

Saturable ethanol binding in rat liver mitochondria

The binding of ethanol to rat liver mitochondria is shown to be saturable at physiologically relevant ethanol concentrations. This effect is reversible and is not observed in extracted mitochondrial phospholipids. Brief exposure of the mitochondria to heat abolishes saturable ethanol binding. Previously, saturable ethanol binding was reported in rat liver microsomes. Taken together, the studies indicate that saturable ethanol binding motifs may be widespread in cellular membranes. The possibility is raised that incomplete expression of the hydrophobic effect in membrane assembly results in the expression of amphipathic packing defects which display an affinity for and a sensitivity to ethanol. The presence of saturable binding modalities is reconciled with the long-standing consensus on the biodistribution of ethanol - that ethanol's interactions with tissue are negligible - on the grounds that the affinities of ethanol and of water for membranes are similar; consequently, free ethanol concentrations are insensitive to the presence of tissue despite significant ethanol binding. A fraction of the binding sites possess submillimolar affinities for ethanol consistent with published functional studies, both in vitro and in vivo, that reported submillimolar efficacies for ethanol.

Evaluation of sympathetic nerve terminals with [(11)C]epinephrine and [(11)C]hydroxyephedrine and positron emission tomography

BACKGROUND

The goal of the present study was to directly compare the new radiopharmaceutical agent [(11)C]epinephrine (EPI) with [(11)C]hydroxyephedrine (HED) through the use of PET.

METHODS AND RESULTS

Seven healthy volunteers and 10 patients were investigated after heart transplantation. PET images of both tracers were of excellent quality in the volunteers. Values for radiolabeled metabolites (measured in percent of blood activity) at 5, 20, and 60 minutes after injection were approximately 35%, approximately 82%, and approximately 86% for EPI and approximately 13%, approximately 47%, and approximately 78% for HED, respectively. At 35 minutes, metabolite-corrected mean myocardial retention fraction of EPI (0. 235+/-0.022 min(-1)) was significantly greater (P<0.01) than that of HED (0.142+/-0.012 min(-1)). Corrected tracer retention fractions of both EPI and HED were significantly reduced in transplant recipients (0.055+/-0.004 min(-1), P<0.0001; and 0.050+/-0.006 min(-1), P<0. 0001, respectively) compared with volunteers. Normalization of retention fractions of patients with transplantation within 1 year to volunteers resulted in a value (ratio expressed in percent) of 20. 6+/-1.8% for EPI, significantly (P<0.03) smaller than 27.8+/-0.8% for HED. In patients with transplantation later than 1 year, the values were 26.0+/-2.9% for EPI compared with 44.2+/-5.6% for HED (P<0.014).

CONCLUSIONS

Both tracers showed high selectivity for neuronal uptake in the heart, with a significant reduction in tracer retention in transplant recipients compared with volunteers. Compared with HED, EPI showed greater retention in volunteers and a lower retention ratio in transplant recipients, suggesting that EPI may be the superior tracer with higher sensitivity to neuronal abnormalities. Because EPI reflects neuronal uptake, metabolism, and storage, it may be more suitable for the study of neuronal integrity than HED, which primarily traces uptake-1 capacity.

Hypopharyngeal perforation during laparoscopic Roux-en-Y gastric bypass

Laparoscopic Roux-en-Y gastric bypass was recently introduced as an alternative surgical treatment for morbid obesity. The technique involves placement of a 21-mm anvil transorally down to the gastric pouch for creation of the gastroenterostomy anastomosis using an EEA stapler placed transabdominally. Esophageal injury is a theoretical concern with transoral manipulation of the anvil. The authors present a case of hypopharyngeal perforation after an attempted transoral insertion of an EEA anvil. The perforation was treated with neck exploration and drainage. We discuss the mechanism of injury and alternative method for placement of the gastric anvil.

Acoustic streaming in micromachined flexural plate wave devices: numerical simulation and experimental verification

This paper presents the numerical simulation and experimental validation of acoustic streaming in micromachined flexural plate wave (FPW) devices. Two-dimensional and three-dimensional models of two device types were considered: the classical device with parallel interdigitated electrodes and the focused device with curved electrodes. Influences of different parameters on the time-averaged velocity were investigated. Thermal transport effects of the acoustic streaming were also considered. We observed the amplifying effect of the streaming in the second type numerically and experimentally. To verify simulation results, the method of the particle image velocimetry (PIV) was applied in the experimental investigation.

Comparison of prevalence of feline herpesvirus type 1, calicivirus and parvovirus infections in domestic and leopard cats in Vietnam

A serosurvey of feline herpesvirus type 1 (FHV-1), feline calicivirus (FCV), and feline parvovirus (FPV) in cats from Ho Chi Minh City area in southern Vietnam was conducted in December 1998, and we compared the results with our previous results in northern Vietnam (Hanoi area). The positive rate of FHV and FCV in domestic cats were 44% and 74%, respectively. They were rather higher than those in Hanoi area, while the seropositivity of FPV (44%) was similar to that in Hanoi area. In leopard cats, the positive rate of FPV was high (3/4) and it indicated that FPV was prevailing in leopard cats in Vietnam.

Laparoscopic Roux-en-Y gastric bypass for super/super obesity

Laparoscopic gastric bypass has been recently introduced as an alternative method to conventional open gastric bypass. This procedure has been generally limited to patients with a BMI <60 kg/m2 due to the possible technical limitations of the laparoscopic instruments. In this article, we present a patient with super/super obesity (61 kg/m2) who underwent Rouxen-Y gastric bypass using the laparoscopic approach.

Effect of open and laparoscopic surgery on cellular immunity in a swine model

Immune suppression associated with trauma has been demonstrated to be proportional to the magnitude of injury. Laparoscopic surgery has been shown to produce a diminished stress response compared to open surgery. Postoperative immune function, specifically cellular immunity, may be better preserved after laparoscopic surgery compared to open surgery. The aim of this study was to examine the effect of open versus laparoscopic surgery on cellular immunity in a swine model. Twenty domestic female pigs were randomly selected for laparoscopic cholecystectomy (LC) or open cholecystectomy (OC). Cellular immune functions were evaluated with delayed-type hypersensitivity (DTH) skin test and serial phytohemoagglutinin (PHA)-induced T-cell proliferation of the peripheral blood. There was a significant reduction in PHA-induced T-cell proliferation in both LC and OC groups on days 1 and 3 compared to preoperative values (p < 0.05). The reduction of mitogen-induced T-cell proliferation after LC was significantly less than after OC on day 1 (p = 0.03). The mean DTH reaction was 29.7 +/- 3.7 mm2 in the LC group compared to 13.9 +/- 1.2 mm2 in the OC group (p < 0.001). There was no difference in postoperative white blood count values between the two groups. Suppression of cellular immunity occurred after both LC and OC. The magnitude and duration of impaired cellular immunity after laparoscopic surgery was less than after open surgery as measured by T-cell proliferation and DTH response.

Photodynamic therapy for treatment of malignant dysphagia

Photodynamic therapy (PDT) was recently approved by the Food and Drug Administration for palliating obstructing esophageal cancer. This report reviews our initial experience using PDT to treat malignant dysphagia. Patients with inoperable, obstructing esophageal cancer were considered for PDT. Photofrin was injected 48 hours before endoscopic laser activation. Dysphagia score was assessed. Thirty patients underwent 53 PDT courses. Improvement in dysphagia occurred in 83%. Mean dysphagia score decreased from 2.8 to 1.8 (p < 0.05). Complications included esophageal stricture (9.4%), candida esophagitis (5.7%), symptomatic pleural effusion (5.7%), contained esophageal perforation (1.9%), aspiration pneumonia (1.9%), and sunburn (13.2%). Seventeen patients (57%) required more than one PDT treatment, and in 10 an expandable metal stent was used as an adjunct. The 30-day mortality rate was 7%. PDT is effective in palliating patients with malignant dysphagia. The ideal patient for PDT has an obstructing, primarily endoluminal esophageal tumor with minimal extrinsic compression.

One and the same androgen for all? Towards designer androgens

The introduction of designer oestrogens as a treatment modality in hormone replacement in women has invited to consider the concept of compounds with selective androgenic effects for male hormone replacement therapy. The full spectrum of the actions of testosterone may not be necessary of even undesired for certain indications for testosterone treatment. To define for what indications certain androgenic properties are desired and undesired more insight in basic androgen (patho)physiology is required. There is convincing evidence that aromatization of androgenic compounds to oestrogens might be an advantage for maintenance of bone mass and it might also mitigate negative effects of androgens on biochemical parameters of cardiovascular risks; the potentially negative effects of oestrogens on prostate pathology in ageing men needs further elucidation. While the role of dihydro-testosterone (DHT) for the male sexual differentiation and for pubertal sexual maturation is evident, its role in mature and ageing males seems less significant or may even be harmful. It is, however, of note that a negative effect of DHT on prostate pathophysiology is certainly not proven. For male contraception a progestational agent with strong androgenic properties might be an asset. For most of the androgenic actions the critical levels of androgens are not well established. The latter is relevant since the large amount of androgen molecules required for its biological actions (as compared to oestrogens) is an impediment in androgen replacement modalities. There may be room for more biopotent androgens since delivery of large amounts of androgen molecules to the circulation poses problems for treatment modalities.

Sugar ring distortion in the glycosyl-enzyme intermediate of a family G/11 xylanase

The 1.8 A resolution structure of the glycosyl-enzyme intermediate formed on the retaining beta-1,4-xylanase from Bacillus circulans has been determined using X-ray crystallographic techniques. The 2-fluoro-xylose residue bound in the -1 subsite adopts a 2,5B (boat) conformation, allowing atoms C5, O5, C1, and C2 of the sugar to achieve coplanarity as required at the oxocarbenium ion-like transition states of the double-displacement catalytic mechanism. Comparison of this structure to that of a mutant of this same enzyme noncovalently complexed with xylotetraose [Wakarchuk et al. (1994) Protein Sci. 3, 467-475] reveals a number of differences beyond the distortion of the sugar moiety. Most notably, a bifurcated hydrogen bond interaction is formed in the glycosyl-enzyme intermediate involving Heta of Tyr69, the endocyclic oxygen (O5) of the xylose residue in the -1 subsite, and Oepsilon2 of the catalytic nucleophile, Glu78. To gain additional understanding of the role of Tyr69 at the active site of this enzyme, we also determined the 1.5 A resolution structure of the catalytically inactive Tyr69Phe mutant. Interestingly, no significant structural perturbation due to the loss of the phenolic group is observed. These results suggest that the interactions involving the phenolic group of Tyr69, O5 of the proximal saccharide, and Glu78 Oepsilon2 are important for the catalytic mechanism of this enzyme, and it is proposed that, through charge redistribution, these interactions serve to stabilize the oxocarbenium-like ion of the transition state. Studies of the covalent glycosyl-enzyme intermediate of this xylanase also provide insight into specificity, as contacts with C5 of the xylose moiety exclude sugars with hydroxymethyl substituents, and the mechanism of catalysis, including aspects of stereoelectronic theory as applied to glycoside hydrolysis.

Sequence comparison of the VP2 variable region of infectious bursal disease virus isolates from Vietnam

The variable region in the VP2 gene of twenty-three infectious bursal disease virus (IBDV) isolates, collected in Vietnam in 1997 and 1998, was amplified as cDNA by using the reverse transcription-polymerase chain reaction and sequenced. Analysis of amino acid substitutions and phylogenetic relationships of the deduced amino acid sequences (residues 206-350) showed that the nineteen Vietnamese vv IBDVs clustered with the European vv IBDVs, Japanese vv IBDVs and Chinese vv strains, and that the four vietnamese virulent strains were closely related to European virulent strain 52/70. These results suggest that Vietnamese vv IBDVs, European vv IBDVs, Japanese vv IBDVs and Chinese vv strains have the same origin.

Pulmonary embolism following laparoscopic antireflux surgery: a case report and review of the literature

Deep venous thrombosis and pulmonary embolism are concerning causes of morbidity and mortality in patients undergoing general surgical procedures. Laparoscopic surgery has gained rapid acceptance in the past several years and is now a commonly performed procedure by most general surgeons. Multiple anecdotal reports of pulmonary embolism following laparoscopic cholecystectomy have been reported, but the true incidence of deep venous thrombosis and pulmonary embolism in patients undergoing laparoscopic surgery is not known. We present a case of pulmonary embolism following laparoscopic repair of paraesophageal hernia. The literature is then reviewed regarding the incidence of pulmonary embolism following laparoscopic surgery, the mechanism of deep venous thrombosis formation, and the recommendations for deep venous thrombosis prophylaxis in patients undergoing laparoscopic procedures.

Laparoscopic Roux-en-Y gastric bypass for morbid obesity

Surgery is currently the only effective treatment for morbid obesity. The two most commonly accepted operations are the Roux-en-Y gastric bypass and vertical banded gastroplasty. Although multiple authors have reported on a laparoscopic approach to gastric banding, the Roux-en-Y gastric bypass is a complex operation to be replicated using laparoscopic techniques. In this article, we describe our technique of the Roux-en-Y gastric bypass using a laparoscopic approach in four cases.

Detection of micrometastases in histologically negative lymph nodes in esophageal cancer

BACKGROUND

New molecular techniques may identify micrometastases in histologically negative lymph nodes and have an impact on the staging of esophageal cancer. We investigated the role of the reverse transcriptase-polymerase chain reaction (RT-PCR) assay to identify micrometastases in esophageal cancer.

METHODS

The RT-PCR assay to detect carcinoembryonic antigen (CEA) messenger ribonucleic acid (mRNA) was performed on lymph nodes from patients with esophageal cancer and benign esophageal disorders. The presence of CEA mRNA in lymph nodes was considered evidence of metastases.

RESULTS

Histopathologic study revealed metastases in 50 (41%) of 123 lymph nodes from 30 patients with esophageal cancer. All histologically positive lymph nodes contained CEA mRNA by RT-PCR. Of 73 histologically negative lymph nodes, 36 (49%) contained CEA mRNA, a significant increase compared with the histopathologic diagnosis (p < 0.001). Lymph nodes in patients with benign disease contained no CEA mRNA. In 10 patients, histologic stage was NO. Five of them were also negative by RT-PCR, and all are alive with only one recurrence. In the remaining 5 patients, RT-PCR was positive for occult lymph node metastases; 2 have died of disease, and 1 is alive with recurrent disease.

CONCLUSIONS

In patients with esophageal cancer, RT-PCR detects more lymph node metastases than does histopathology. Initial follow-up suggests a positive RT-PCR with negative histologic findings may have poor prognostic implications. Further studies will be needed to confirm any clinical implications.

The etiology of bacterial pneumonia and meningitis in Vietnam

BACKGROUND

To date no studies on the incidence of Haemophilus influenzae type b (Hib) disease, Hib carrier rates in infants and children or the proportion of bacterial meningitis cases caused by Hib in Vietnam have been performed. The availability of safe and highly effective Hib vaccines makes such information important.

METHODS

The bacterial etiology of a sample of infants and children with pneumonia and meningitis seen at Pediatric Hospital No. 1 in Ho Chi Minh City was studied by culture and latex agglutination of blood, cerebrospinal fluid, urine and pleural fluid. The carriage rate of pneumococci and Hib was studied in a sample of outpatient children.

RESULTS

Hib caused 53% of 34 culture-proven bacterial meningitis cases and pneumococci caused 18%. Of 31 meningitis cases diagnosed by latex agglutination, 39% were caused by Hib and 55% by pneumococci. Ninety percent of cases of Hib meningitis occurred in children <1 year of age. Fifty percent of meningitis cases were associated with acute respiratory infection. In 213 bacteremic pneumonia cases 92.5% of blood cultures grew Streptococcus pneumoniae and only 1% grew Hib. The carrier rate of Hib in outpatients <5 years of age with upper respiratory tract infection increased from 2% to 7.6% between 1993 and 1996.

CONCLUSION

Hib is the most frequent cause of meningitis in infants and children admitted to hospitals in South Vietnam. Ninety percent of Hib meningitis cases occur in patients < 1 year of age. Bacteremic Hib pneumonia in Vietnam is rare. The results suggest that Hib is the major cause of meningitis in Vietnam but do not permit conclusions regarding its true incidence. The carrier rate of Hib in children <5 years of age in Vietnam has increased to approximately 7% since 1993.

Coagulation modifications after laparoscopic and open cholecystectomy in a swine model

BACKGROUND

The stress response to surgical trauma precipitates a state of transient hypercoagulation. Studies have demonstrated that laparoscopic surgery results in a diminished stress response compared to open surgery. The aim of this study was to determine the extent of postoperative hypercoagulability following laparoscopic cholecystectomy (LC) compared to open cholecystectomy (OC).

METHODS

Twenty-one pigs were randomly selected to undergo LC (N = 10) or OC (N = 11). Whole blood was collected preoperatively and on postoperative days (PODs) 1, 2, and 3 for determination of viscoelastic changes using a thromboelastography (TEG) coagulation analyzer. Four parameters were calculated from the TEG: R (reaction time), K (coagulation time), alpha (rate of clot formation), and MA (maximal amplitude). Antithrombin III (AT III) level was measured preoperatively and on POD 1.

RESULTS

After OC, three of four TEG parameters changed to reflect a state of hypercoagulation. Only MA values were significantly changed after LC. Comparison between OC and LC showed no difference in the TEG parameter. There was no significant change in AT III levels after LC or OC.

CONCLUSIONS

OC results in postoperative hypercoagulation typically encountered in open abdominal surgery. Although there were no differences in TEG or AT III between the two groups, after the laparoscopic approach all but one TEG parameter remained unchanged, suggesting a diminished hypercoagulable state. By reducing postoperative hypercoagulation, laparoscopic surgery may reduce the risk of developing postoperative venous thrombosis.

Preliminary results of thoracoscopic Belsey Mark IV antireflux procedure

Laparoscopic Nissen fundoplication has replaced open approaches for refractory gastroesophageal reflux disease (GERD) in many major medical centers. Here we report our preliminary results of the Belsey Mark IV antireflux procedure performed by video-assisted thoracoscopy (VATS-Belsey). Fifteen patients underwent VATS-Belsey. The indications for surgery included GERD refractory to medical therapy (n=10), achalasia (n=2), diffuse esophageal spasms (n=1), epiphrenic esophageal diverticulum (n=1), and paraesophageal hernia (n=1). The median operative time was 235 min. There were three conversions to open minithoracotomy (8-10 cm) necessitated by severe adhesions (n=2) and repair of a gastric perforation (n=1). The median hospital stay was 4 days. Postoperative complications included persistent air leaks, requiring discharge with a Heimlich valve in one patient. There were no perioperative deaths. At a median follow-up of 19 months, ten patients (66%) were asymptomatic and were not taking any antacids. One patient who had taken proton pump inhibitors preoperatively required postoperative H2 blockers for mild heartburn. In three patients, recurrent GERD symptoms (mean follow-up 6 months) led to laparoscopic takedown of the Belsey and Nissen fundoplication. One patient with achalasia, who had recurrent dysphagia after 1 year of relief following VATS myotomy and Belsey, underwent esophagectomy. The Belsey Mark IV antireflux procedure is technically feasible by VATS with minimal morbidity. However, our preliminary results suggest that open thoracotomy for Belsey Mark IV should remain the standard operation for GERD with poor esophageal motility when a thoracic approach is desired. We have modified our approach to laparoscopic partial fundoplications (Toupet or Dor) for severe GERD and poor esophageal motility when an abdominal approach is possible.

Structural and spectroscopic studies of azide complexes of horse heart myoglobin and the His-64-->Thr variant

The high-resolution X-ray crystallographic structures of horse heart azidometmyoglobin complexes of the wild-type protein and the His-64-->Thr variant have been determined to 2.0 and 1.8 A respectively. Azide binds to wild-type metmyoglobin in a bent configuration with an Fe-N-1-N-3 angle of 119 degrees and is oriented into the distal crevice in the direction of Ile-107. The proximity of the His-64 NE2 atom to the N-1 atom of the bound azide indicates stabilization of the ligand by the His-64 side chain through hydrogen bonding. In addition, structural characterization of wild-type horse heart azidometmyoglobin establishes that the only structural change induced by ligand binding is a small movement of the Leu-29 side chain away from the azide ligand. EPR and Fourier transform infrared spectroscopy were used to characterize the myoglobin azide complexes further. EPR spectroscopy revealed that, in contrast with wild-type azidometmyoglobin, two slightly different low-spin species are formed by azide bound to the His-64-->Thr variant both in solution and in a polycrystalline sample. One of these low-spin species has a greater relative intensity, with g values very similar to those of the azide complex of the wild-type protein. These EPR results together with structural information on this variant indicate the presence of two distinct conformations of bound azide, with one form predominating. The major conformation is comparable to that formed by wild-type myoglobin in which azide is oriented into the distal crevice. In the minor conformation the azide is oriented towards the exterior of the protein.

Minimally invasive approach to esophagectomy

BACKGROUND

Recent advances in laparoscopic and thoracoscopic surgery have made it possible to perform esophagectomy using minimally invasive techniques. The aim of this report was to present our preliminary experience with minimally invasive esophagectomy.

METHODS

We reviewed our experience on eight patients who underwent minimally invasive esophagectomy using either laparoscopic and/or thoracoscopic techniques from June 1996 to May 1997. Indications for esophagectomy included stage I carcinoma (5), palliative resection (1), Barrett's with high grade dysplasia (1) and end stage achalasia (1).

RESULTS

The average age was 68 years (54-82). The surgical approach to esophagectomy included laparoscopic transhiatal esophagectomy with cervical anastomosis (n = 4), thoracoscopic and laparoscopic esophagectomy with cervical anastomosis (n = 1), and laparoscopic mobilization with right mini-thoracotomy and intra-thoracic anastomosis (n = 3). Conversion to mini-laparotomy was required in two patients (25%) to complete esophageal dissection and facilitate gastric pull-up. The mean operative time was 460 minutes. The mean intensive care stay was 1.9 days (range of 0-7 days) with a mean hospital stay of 13.8 days. Minor complications included atrial fibrillation (n = 1), pleural effusion (n = 2) and persistent air leak (n = 1). Major complications included cervical anastomotic leak (n = 1), and delayed gastric emptying requiring pyloroplasty (n = 1). There was no perioperative mortality.

CONCLUSIONS

This preliminary experience suggests that minimally invasive esophagectomy is safe and feasible in centers with experience in advanced minimally invasive surgical procedures. Further studies are necessary to determine advantages over open esophagectomy.

Laparoscopic transhiatal esophagectomy for Barrett's esophagus with high grade dysplasia

BACKGROUND

A number of case reports have described the application of minimally invasive surgical techniques to accomplish esophagectomy. However, most reports have employed thoracoscopic or laparoscopic techniques to perform esophagectomy in addition to an "access" incision which often approaches a standard laparotomy or thoracotomy.

CASE REPORT

This report describes a total laparoscopic transhiatal esophagectomy in a 55 year old female with Barrett's esophagus and high grade dysplasia.

CONCLUSIONS

The patient had an uneventful recovery and was discharged home on the fourth day after a total laparoscopic esophagectomy. This report demonstrates the technical feasibility of this complex procedure by a minimally invasive approach.

Characterization of Lnk. An adaptor protein expressed in lymphocytes

Stimulation of the T cell antigen receptor (TCR) activates a set of non-receptor protein tyrosine kinases that assist in delivering signals to the cell interior. Among the presumed substrates for these kinases, adaptor proteins, which juxtapose effector enzyme systems with the antigen receptor complex, figure prominently. Previous studies suggested that Lnk, a 38-kDa protein consisting of a single SH2 domain and a region containing potential tyrosine phosphorylation sites, might serve to join Grb2, phospholipase C-gamma1, and phosphatidylinositol 3-kinase to the TCR. To elucidate the physiological roles of Lnk in T cell signal transduction, we isolated the mouse Lnk cDNA, characterized the structure of the mouse Lnk gene, and generated transgenic mice that overproduce Lnk in thymocytes. Here we report that although Lnk becomes phosphorylated during T cell activation, it plays no limiting role in the TCR signaling process. Moreover, we have distinguished p38(Lnk) from the more prominent 36-kDa tyrosine phosphoproteins that appear in activated T cells. Together these studies suggest that Lnk participates in signaling from receptors other than antigen receptors in lymphocytes.

Myocardial kinetics of carbon-11-epinephrine in the isolated working rat heart

The kinetics of EPI were studied in the isolated rat heart model to evaluate 11C-epinephrine (EPI) as a radiotracer for the assessment of sympathetic neuronal function in the heart.

METHODS

Isolated rat hearts were perfused in a working mode. Carbon-11-EPI was added to the perfusate during wash-in period of 20 min, followed by a washout period of 40 min. Radioactivity in the heart was externally monitored and time-activity curves were recorded as a function of time. Effluent samples were collected throughout each study to determine the fraction of 11C radioactivity as intact tracer.

RESULTS

Time-activity curves of control hearts showed that 11C-EPI is taken up and retained by the myocardium. Desipramine inhibition (DMI) of uptake-1 resulted in a significant decrease in myocardial uptake and retention of 11C-EPI by 91% compared to controls. Addition of DMI to the perfusion medium during washout did not affect kinetics of 11C-EPI compared to control hearts. Reserpine pretreated rat hearts also showed significant decrease in tracer retention of 95% compared to controls. The metabolic data showed that, in control conditions, about 61% of 11C-EPI taken up by the rat heart is rapidly metabolized and released.

CONCLUSION

Carbon-11-EPI traces sympathetic nerve terminals in the isolated rat heart. Uptake blockade by DMI and reserpine suggest that uptake and storage of 11C-EPI appear to be similar to that of norepinephrine. However, the prominent metabolic pathway warrants further consideration. These results suggest that 11C-EPI may be a suitable radiolabeled tracer for the evaluation of sympathetic vesicular function of the heart by PET.

[Hemostasis before retropubic prostatic adenomectomy using temporary clamping of the vesicogenital arteries]

Prostatectomy can be performed via several approaches, but the main problem concerns haemostasis before, during and after prostatectomy. A first series of 187 cases of retropubic prostatectomy was performed, between 1980 and 1989, by bilateral ligation of the genitovesical arteries, associated with suture-ligation of the periprostatic veins prior to prostatic resection. In a second series of 50 cases (1990-1992), the same technique was applied, but with temporary clamping instead of ligation of the 2 genitovesical arteries. This method of haemostasis allowed us to operate in a relatively bloodless field (blood loss less than 150 mL in 80% of cases), prevented immediate or secondary postoperative haemorrhages and simplified the postoperative surveillance.

Capillary electrophoresis of cardiovascular drugs

This review surveys the use of capillary electrophoresis for the analysis of cardiovascular drugs. Each section presents examples of separations according to the class of the cardiovascular agent. The classes presented are beta-adrenergic antagonists (beta-blockers), acetylcholinesterase inhibitors, angiotensin-converting enzyme inhibitors, dieuretics, alpha-adrenergic antagonists, calcium channel blockers, cardiac glycosides, hypolipidemics (HmG-CoA reductase inhibitors and fibric acid), vasodilators and sodium channel blockers. Examples of the separation modes discussed include capillary electrophoresis, micellar electrokinetic chromatography using many additives (e.g. sodium dodecyl sulfate, cyclodextrins, bile salts, proteins, oligosaccharides) and isotachophoresis.

[Oral candidiasis: diagnosis and drug therapy]

Oral candidiasis is the most frequently observed oral mycosis. It can be manifested as a variety of clinical symptoms, and both local and systemic factors may contribute to its development. A confirmation of this infection depends upon the use of appropriate diagnostic tests, in addition to the presence of clinical signs and symptoms. The choice of antifungal agent depends on the location, severity and chronicity of the lesions, as well as the health status of the patient. Oral candidiasis generally responds well to pharmacological treatment. If the infection is persistent or recurrent, a possible underlying homeostatic disturbance should be investigated.

Agent Orange and the Vietnamese: the persistence of elevated dioxin levels in human tissues

OBJECTIVES

The largest known dioxin contamination occurred between 1962 and 1970, when 12 million gallons of Agent Orange, a defoliant mixture contaminated with a form of the most toxic dioxin, were sprayed over southern and central Vietnam. Studies were performed to determine if elevated dioxin levels persist in Vietnamese living in the south of Vietnam.

METHODS

With gas chromatography and mass spectroscopy, human milk, adipose tissue, and blood from Vietnamese living in sprayed and unsprayed areas were analyzed, some individually and some pooled, for dioxins and the closely related dibenzofurans.

RESULTS

One hundred sixty dioxin analyses of tissue from 3243 persons were performed. Elevated 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) levels as high as 1832 ppt were found in milk lipid collected from southern Vietnam in 1970, and levels up to 103 ppt were found in adipose tissue in the 1980s. Pooled blood collected from southern Vietnam in 1991/92 also showed elevated TCDD up to 33 ppt, whereas tissue from northern Vietnam (where Agent Orange was not used) revealed TCDD levels at or below 2.9 ppt.

CONCLUSIONS

Although most Agent Orange studies have focused on American veterans, many Vietnamese had greater exposure. Because health consequences of dioxin contamination are more likely to be found in Vietnamese living in Vietnam than in any other populations, Vietnam provides a unique setting for dioxin studies.

Effect of diclofenac sodium (Voltaren) on hypoxia-induced corneal edema in humans

We evaluated the effect of diclofenac sodium (Voltaren) drops on patients with hypoxia-induced corneal edema. Thirty age- and sex-matched subjects were randomly assigned to one of three groups. Members of each group received masked solutions of either Voltaren, Voltaren vehicle, or a non-preserved lubricant (Cellufresh) every 6 hours for 24 hours and then hourly for 2 hours immediately prior to inducing corneal edema in the experimental eye. Bilateral ultrasonic pachymetry was performed prior to applying a thick contact lens and light patch on the experimental eye of all subjects for 3 hours. The fellow eye served as the control. Following lens removal, bilateral corneal thickness was measured every 30 minutes. The percentage change in corneal swelling for each subject and group was calculated. The findings were also normalized to the control eye to minimize diurnal and individual variability. The results were plotted both as percentage change from hour 0 and percentage change normalized to the control eye. Corneal swelling ranged from 9-11% in all 3 groups, with recovery at 2-3 hours. No significant difference was found among the three groups (P > 0.05, ANOVA). There was a slight trend toward reduced thickness in the Cellufresh group, but this was not statistically significant. Voltaren does not appear to have an effect on the hypoxia-induced corneal edema associated with the production of arachidonic acid pathway metabolites.

Cloning and characterization of rabbit liver UDP-glucuronosyltransferase cDNAs. Developmental and inducible expression of 4-hydroxybiphenyl UGT2B13

A polyclonal antibody generated against rabbit liver p-nitrophenol UDP-glucuronosyltransferase (UGT) was used to screen a rabbit liver cDNA expression library constructed in lambda gt11. A 500-base pair cDNA clone, termed pPNP, generated a fusion protein that was antigenic with the antibody. Clone pPNP encoded the 3' region of a UGT. To identify larger recombinants, clone pPNP was used as a probe to screen a second cDNA library constructed in lambda ZAP. Two different cDNA clones were identified by DNA sequence analysis. Based upon their predicted amino acid sequence analysis, the clones encode transferases belonging to the UGT2 subfamily, and have been identified as UGT2B13 and UGT2B14. The predicted N-terminal sequence of UGT2B13 is identical to that determined for the purified rabbit liver estrone UGT. However, expression of the UGT2B13 cDNA in COS-1 cells displayed no activity in the presence of estrone but efficiently conjugated 4-hydroxybiphenyl. Results of Southern blot analysis using the 5' divergent region of the UGT2B13 cDNA that encodes exon 1 demonstrates that multiple genes share sequence homology to UGT2B13, an observation which indicates that the estrone UGT and UGT2B13 genes are encoded by separate alleles. When the 5' variable regions of the cDNAs where used in Northern blot analysis, the expression of UGT2B13 and UGT2B14 were shown to be expressed primarily in adult rabbits. However, when neonatal rabbits were treated with either dexamethasone or rifampicin, UGT2B13 mRNA levels were induced. The neonatal induction of UGT2B13 mRNA corresponded with similar increases in 4-hydroxybiphenyl UGT activity. The expression and induction of UGT2B13 paralleled that of the developmentally regulated rabbit liver progesterone 6 beta-hydroxylase P4503A6.

An evaluation of xeroradiographs and radiographs in length determination in endodontics

Twelve block sections of mandibles containing incisors, canines, premolars, and molars were dissected from human cadavers (total, 26 teeth). Endodontic access was achieved, and a No. 10 k-type endodontic file was inserted to a point approximately 1 to 2 mm short of the radiographic apex. By securing the mandible and Rinn instrument with plaster mounts, exposures were made from identical angles and film and jaw placement remained constant in both techniques. Conventional film images were recorded on Kodak Ultraspeed film with six to eight impulses. Xeroradiographic images were recorded with four to five impulses. Radiographs and xeroradiographs were evaluated with the use of light from a masked viewbox. A magnifying glass was used to evaluate visualization of the following entities: the root apex; the periodontal ligament; the trabecular pattern; and the measuring instruments. The images were examined and categorized by three examiners, who used the following scores: 3, optimal for diagnostic information; 2, adequate for diagnostic information; 1, poor but providing diagnostic information; and 0, unacceptably poor. In all categories examined, the information provided by xeroradiographs was significantly greater than that provided by conventional radiographs (p less than .05). In terms of diagnostic value and lower patient dose, xeroradiographs are preferred to conventional radiographs.

Paresthesia of the mental nerve after overextension with AH26 and gutta-percha: report of case

Overfilling of a root canal with AH26 and gutta-percha resulted in paresthesia of the mental nerve. After 14 weeks, nerve function was restored.

Transcriptional regulation of the MET3 gene of Saccharomyces cerevisiae

The MET3 gene, coding for ATP sulfurylase (ATPS), an enzyme implicated in methionine biosynthesis in Saccharomyces cerevisiae, was cloned by functional complementation, after transformation, of a yeast met3 mutant strain. The cloned MET3 gene was used as a probe to measure the specific MET3 messenger RNA in a wild-type strain grown under conditions which promote or fail to promote repression of ATPS synthesis. It was found that the level of MET3 messenger RNA is reduced ten-fold when the strain is grown under conditions where ATPS synthesis is repressed, suggesting that the MET3 expression is regulated transcriptionally. The direction of transcription and the size of the transcript have been determined.