PubMed Health⌕ Search

Biomedical subjects

S W Unger

Publications and source records attributed to S W Unger.

18 recordsLinked to original sources
PubMed1992

Resident education in surgical endoscopy.

Under the auspices of the Resident Education Committee of the Society of American Gastrointestinal Endoscopic Surgeons, 158 of 298 (53%) of surgical training program directors responded to a survey on the current status of endoscopy in residency programs. Although 100 per cent claim that gastrointestinal endoscopy is provided by their program, only 76 per cent have formal endoscopy training, usually centered around the PGY 3 level, with only 23 per cent having didactic lectures in endoscopy. Directors claim to have trained nearly all of their residents by the completion of residency, averaging 44 esophagogastroscopies, 37 colonoscopies, and 46 flexible sigmoidoscopies per resident. However, they feel only 71 per cent of trainees are able to perform esophagogastroscopies and 67 per cent to perform colonoscopies in clinical practice. Ninety-seven per cent of directors feel endoscopy is important to surgical residency training, and 87 per cent have full-time faculty doing endoscopy. Only 44 per cent have a director of endoscopy; endoscopy is supervised by surgeons exclusively in only 48 per cent. Only 35 per cent have ongoing endoscopy research. When surgeons are not performing endoscopy, 66 per cent feel that the gastrointestinal (GI) service provides adequate service or training. Gastroenterology has a monopoly in endoscopy at 28 per cent of institutions, and 67 per cent of program directors feel there would be resistance to the formation of a separate surgical endoscopy service. Surgeons work in their own surgical endoscopy suite in only 15 per cent of institutions; in a GI suite in 13 per cent; and in a combined suite in the remainder.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗
PubMed1991

Proton nuclear magnetic resonance study of the solution distal histidine orientation in monomeric Chironomus thummi thummi cyanomet hemoglobins. Dynamic stability of the heme pocket as monitored by labile proton exchange.

The 1H nuclear magnetic resonance spectral characteristics of the cyano-Met form of Chironomus thummi thummi monomeric hemoglobins I, III and IV in 1H2O solvent are reported. A set of four exchangeable hyperfine-shifted resonances is found for each of the two heme-insertion isomers in the hyperfine-shifted region downfield of ten parts per million. An analysis of relaxation, exchange rates and nuclear Overhauser effects leads to assignments for all these resonances to histidine F8 and the side-chains of histidine E7 and arginine FG3. It is evident that in aqueous solution, the side-chain from histidine E7 does not occupy two orientations, as found for the solid state, rather the histidine E7 side-chain adopts a conformation similar to that of sperm whale myoglobin or hemoglobin A, oriented into the heme pocket and in contact with the bound ligand. Evidence is presented to show that the allosteric transition in the Chironomus thummi thummi hemoglobins arises from the "trans effect". An analysis of the exchange with bulk solvent of the assigned histidine E7 labile proton confirms that the group is completely buried within the heme pocket in a manner similar to that found for sperm whale cyano-Met myoglobin, and that the transient exposure to solvent is no more likely than in mammalian myoglobins with the "normal" distal histidine orientation. Finally, a comparison of solvent access to the heme pocket of the three monomeric C. thummi thummi hemoglobins, as measured from proton exchange rates of heme pocket protons, is made and correlated to binding studies with the diffusible small molecules such as O2.

Animals↗
PubMed1991

Laparoscopic approach to gallstones in the morbidly obese patient.

Obesity has been suggested to be a contraindication to laparoscopic cholecystectomy (LC). In our center, in which all patients presenting with symptomatic gallstones are considered to be candidates for LC, 24 of the first 325 LC candidates were retrospectively found to be morbidly obese. In all, 20 were women and 4 were men. The average age was 51 years (range 32 to 83 years); the average height and weight amounted to 72 inches and 298 pounds, respectively, for men; and 63.5 inches and 258 pounds, respectively, for women. One-third of these patients suffered from acute cholecystitis, and more than 50% had undergone prior abdominal surgery. The average duration of LC in these subjects was 114 min., which was 25% longer than that in nonobese patients. The average length of the hospital stay was 1.6 days, with patients returning to normal activities within an average of 6.5 days. There was no major morbidity and no mortality. Since obese patients tolerated LC as easily as did normal patients, we concluded that obesity is an indication rather than a contraindication to LC.

Adult↗
PubMed1991

Laparoscopic treatment of acute cholecystitis.

Retrospective review of the first 210 patients treated by laparoscopic cholecystectomy revealed 55 patients (26%) with acute cholecystitis diagnosed preoperatively or intraoperatively. Average age was 52 years amongst 38 women and 17 men. Cardiac history was present in 4%, pulmonary disease was noted in 9%, and other significant medical history was found in 10%. Abnormal preoperative laboratory values (white blood cell count, liver function) were seen in 80%. Operations averaged 104 minutes. Dissection was performed with the potassium titanyl phosphate (KTP) laser in 9%, neodymium-doped yttrium aluminum garnet (Nd Yag) laser in 20%, and electrocautery alone in 71%. Average body habitus was 5 ft 9 in, 178 lb for men and 5 ft 5 in, 155 lb for women. Average length of stay was 2.6 days. Thirty-eight patients (69%) left the hospital in < 2 days. Postoperative complications included one case each of urinary retention, pneumonia, myocardial infarction, and three cases of postoperative fever. Drains were placed in 10 patients (18%). There was no mortality. Suggestions are made for technical considerations that make laparoscopic cholecystectomy a safe and efficient approach to acute cholecystitis.

Acute Disease↗
PubMed1991

Laparoscopic gastrostomy.

Laparoscopic gastrostomy was performed successfully on six consecutive patients after the procedure was developed using a porcine model. These patients were unable to undergo percutaneous endoscopic gastrostomies because of obstruction from cancer or anatomical blockage. Operative time averaged less than 18 min. Three patients underwent the procedure under local anesthesia with intravenous sedation, and two patients were operated on in a strictly outpatient setting. No complications or deaths occurred. Laparoscopic gastrostomy appears to be a safe alternative to open gastrostomy in patients who cannot undergo percutaneous endoscopic gastrostomy.

Aged↗
PubMed1991

Comparison of operative versus percutaneous endoscopic gastrostomy tube placement in the elderly.

To compare techniques of gastrostomy in elderly patients, the records of 100 patients age 70 and older who underwent gastrostomy tube placement as a primary procedure were reviewed. Two separate unmatched groups of 50 patients each were identified: those that underwent operative gastrostomy tube (OGT) placement and those that underwent percutaneous endoscopic gastrostomy tube (PEG) placement. The groups were studied for demographic similarities and for differences in morbidity, mortality, and ease of feeding. Comparison showed that PEGs had a lower mortality (0%) and morbidity (10%) than did OGTs where mortality was 4 per cent and morbidity was 22 per cent. PEGs began feeding sooner (1.0 day vs. 2.8 days) than OGTs. In addition, almost 60 per cent of the PEG patients underwent complete upper endoscopy at the time of the PEG, which revealed pathology that either altered the type of tube placed or the eventual medical management. PEG offers a less morbid, safer, and easier to use method of gastrostomy tube placement than OGT in the majority of elderly patients.

Aged↗
PubMed1991

Tracheostomy. A new indication for percutaneous endoscopic gastrostomy tube placement.

A review of patients undergoing elective tracheostomy (TRACH) and percutaneous endoscopic gastrostomy (PEG) was undertaken to decide whether addition of PEG to a planned tracheostomy was safe and indicated by conditions mandating the tracheostomy. Charts were reviewed for demographic data, details of operation, outcome, and disposition. Sixteen patients with an average age of 61 years were studied. Primary diagnosis included CNS disease (7), trauma (6), and multisystem failure (3). These patients had 35 associated diseases. Indications for tracheostomy were respiratory failure (9) and prolonged intubation (7). The average time from admission to procedure was 23.7 days. Average operative time was 50 minutes. There were three postoperative complications. Ten patients were discharged (5 home, 5 skilled facility) and six expired. All patients had functioning tracheostomies and PEGs at the time of disposition. Percutaneous endoscopic gastrostomy is a logical adjunct to planned tracheostomy, adding little morbidity but with potential benefit to long-term management in this special group of chronic care patients.

Adult↗
PubMed1991

Percutaneous endoscopic jejunostomy in a patient with previous esophagectomy.

Establishment of a percutaneous endoscopic jejunostomy via direct jejunal puncture was accomplished in a 45-year-old woman five years after a partial esophagectomy with cervical esophagogastrostomy for adenocarcinoma of the esophagus. The patient had recurrence of the cancer at the anastomotic site with subsequent inability to eat, necessitating a feeding tube for prolonged enteral nutrition. Although percutaneous puncture of the jejunum has been previously described, it has been limited to patients who had undergone partial or complete gastrectomies with Bilroth II anastomoses. This case report of direct endoscopic jejunal tube placement in a patient after esophagectomy further establishes this procedure as a viable alternative to surgically placed feeding tubes in patients with altered gastric anatomy.

Anastomosis, Surgical↗
PubMed1990

Single session panendoscopy. Indications and expectations for yield.

To assess the indications and yield of single session panendoscopy (SSPE), patients who underwent colonoscopy and esophagogastroduodenoscopy (EGD) at the same time were retrospectively reviewed. Endoscopy records and patient charts of 101 patients who underwent SSPE during a 45-month period were analyzed for demography, indication, and results. Average age was 72.9 years. Common indications were positive occult blood tests (74%), anemia (28%), altered bowel habits (15%), and iron deficiency (13%). Most frequent findings at colonoscopy included diverticulosis (47%), polyps (37%), hemorrhoids (28%), and arteriovenous (AV) malformations (13%). Nine cases of cancer were found, seven of which were right-sided. Colonoscopy was normal in 12 per cent. EGD findings include esophagitis (55%), hiatal hernia (47%), and gastritis (33%). Eleven per cent were normal. Occult blood loss is not predictive of either a positive or negative study. SSPE is a safe and specific approach; however, based on this study, colonoscopy is recommended as the initial study for occult blood loss with plans to proceed to EGD when the lower endoscopy is normal. Even when the colonoscopy suggests the etiology for occult blood loss, EGD will yield a significant number of treatable and unsuspected lesions.

Adult↗
PubMed1990

Endoscopic Nd-YAG laser treatment of colorectal neoplasms. A four-year longitudinal study.

In order to gain a longitudinal perspective of the benefits, complications, and role of the neodymium yttrium aluminum garnet (Nd-YAG) laser in the treatment of colorectal neoplasms, we performed a review of endoscopies using the laser during a 53-month period ending in January 1989. We reviewed the records of 100 patients for details of the endoscopic procedure and demographic data. Performance status and survival were critically assessed. We performed 275 procedures on 57 men and 43 women with an average age of 76.5 years. An average of 2.75 procedures, each lasting an average of 45 minutes, were performed per patient. Half of the patients had fulgurations of rectal tumors with the common indication being bleeding. Thirteen morbid events and no deaths occurred. Ninety-six per cent of the procedures were performed with the patient under intravenous sedation. The Karnofsky performance scale applied to surviving patients revealed that 90 per cent were able to care for themselves and scored greater than 70. Average survival was 5.58 months. Our results indicate that the Nd-YAG is a safe and effective tool in the treatment of colorectal neoplasms offering palliation as well as maintenance of quality of life.

Adult↗
PubMed1990

Crohn's disease of the appendix.

Crohn's disease limited to the appendix is uncommon. The disease may mimic acute appendicitis with fever, leukocytosis, right lower quadrant pain, and occasionally a palpable mass. When Crohn's disease affects the appendix, it typically has a longer clinical period in which the patient has symptoms than do most cases of acute appendicitis. The most common preoperative diagnoses are acute appendicitis and appendiceal abscess. A review of the literature is presented along with our experience in three additional cases of Crohn's disease limited to the appendix. We suggest that Crohn's disease be included in the preoperative differential diagnosis and that extensive intraoperative examination of the gastrointestinal tract be made in any case of suspected appendicitis that has had a protracted preoperative course.

Adolescent↗
PubMed1989

Percutaneous endoscopic gastrostomy. A mandate for complete diagnostic upper endoscopy.

One hundred patients underwent upper endoscopy for the placement of percutaneous endoscopic gastrostomies (PEGS) during a four year period from 1984 to 1988. These cases were retrospectively reviewed to document the need for total endoscopy during PEG. Ninety-seven per cent of the procedures were successful. In 89 per cent, a complete exam of the esophagus, stomach, and duodenum was performed, revealing pathologic findings in 59 per cent. The most common abnormalities were in the esophagus (23%) and the stomach (27%); however, a portion of the findings were also present in the duodenum (12%) and the pylorus (11%). Additional findings present in the complete esophagogastroduodenoscopy (EGD) done at the time of PEG included a five per cent incidence of gastric outlet obstruction and antral ulcers or polyps in six per cent. The breakdown of findings in the duodenum included eight per cent incidence of duodenal ulcers and four per cent incidence of duodenitis. A total of 22 per cent of the patients had some evidence of peptic ulcer disease. Many of the cases in which pathology was found required a change in medications and, when postoperative bleeding occurred after PEG, the other pathologic entity was much more likely to be the cause of the complication than the PEG. A careful and complete EGD is mandated every time a patient is scheduled for PEG.

Adult↗
PubMed1988

Carbohydrate metabolism of the rat C6 glioma. An in vivo 13C and in vitro 1H magnetic resonance spectroscopy study.

Surface coil 13C nuclear magnetic resonance (NMR) spectroscopy was used to investigate the in vivo carbohydrate metabolism of rat C6 gliomas during and after infusion with [1-13C] glucose. In vivo 1H-decoupled 13C NMR spectra of the glioma following infusion with [1-13C]glucose revealed the direct production of [3-13C]lactic acid, [1-13C]glycogen, and [4-13C], [3-13C], and [2-13C]glutamate/glutamine. Lactate levels of in vivo gliomas increased and reached steady state levels during [1-13C]glucose infusion, and decreased following termination of infusion. Complementary in vitro studies using supernatant media collected from C6 glioma cells incubated with media containing [1-13C] or [6-13C]glucose and glutamine were examined by 1H NMR spectroscopy. The [3-(13C/12C)]lactate ratios obtained from 1H spectra of supernatant media containing [1-13C]glucose revealed the percentage of glucose metabolized through the hexose monophosphate shunt to be 10.01 +/- 0.85% (n = 3), while similar measurements of media containing [6-13C]glucose and glutamine showed that glutaminolysis contributed 9.0 +/- 1.0% of total lactate production under these conditions. Enzymatic analysis of media determined lactate production to be 139 +/- 9 nmol per 10(6) cells per h (n = 4). These measurements demonstrate the ability of NMR to monitor brain tumor carbohydrate metabolism both in vitro and in vivo.

Animals↗
PubMed1988

Nd-YAG laser applications in surgical endoscopy: a single center comprehensive experience.

A retrospective review of endoscopic procedures using the Nd-YAG laser was carried out for patients treated between September 1984 and November 1986. Two hundred twenty two procedures were performed on 104 patients (58M:46W) during this 26 month period. The study encompasses a unique period of time in this center, as it includes the initial use of the endoscopic laser technique, the learning curves associated with its application, and finally, the time when its use became routine. Treatment of tumors was the indication in 47 per cent of the cases. Gastrointestinal bleeding of benign cause was the indication in nearly half of the patients; arteriovenous malformations were the most common causes of bleeding. Laser photocoagulation of hemorrhoids was performed in 11 cases. Upper endoscopy was the route in 33 per cent of procedures. Anoscopy, flexible sigmoidoscopy, and colonoscopy were the routes in the remainder. The time spent on the procedure and the energy delivered were found to be variables of the type of lesion and the endoscopic route. Nd-YAG laser endoscopy can be used safely and effectively for a variety of bleeding and obstructive gastrointestinal conditions. Appropriate certification for granting of privileges to laser endoscopists is of utmost importance.

Adult↗
PubMed1979

The nexus in serial cross-sections of myocardium from cats subjected to hypovolemic shock. A three-dimensional interpretation.

Right ventricular papillary muscles from control cats and from cats subjected to hypovolemic shock were studied in cross-section, including serial sections, by electron microscopy. Loops of nexus and a redundant right angle nexus were followed through serial cross-sections in papillary muscles from the shock cats. These unusual nexus configurations were interpreted as a possible means of connecting perpendicular sheets of nexus, of interdigitating adjacent cells, and of providing slack to be taken up during the radial swelling of myocardial contraction. The flexibility of the intercalated disc which is implicit in this interpretation may explain the ability of cardiac myocytes to recover from the severe distortions adjacent to the intercalated disc which occur in myocardial zonal lesions, and perhaps, if they are reversible, in other lesions which occur in proximity to the intercalated disc.

Animals↗
PubMed1975

The relationship of actin and myosin filaments within myocardial zonal lesions.

Cross sections, including serial sections, of myocardial zonal lesions in right vetricular papillary muscles of cats subjected to hypovolemic shock were examined by electron microscopy. It was determined that the basic structure of A and I bands was retained even in severe zonal lesions with herniation of A and I bands through the intercalated disc into adjacent myocytes. The herniated A and I bands, together with accompanying mitochondria, were enclosed in membranes, apparently the unspecialized portion of the intercalated disc. Since the longitudinal orientation of myofilaments is retained in zonal lesions, this study indicates that intact A and I bands must slide past one another during the supercontraction of sarcomeres which is characteristic of zonal lesions. This study also presents evidence that the nexus may become involved in zonal lesions.

Actins↗