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Biomedical subjects

K L Koch

Publications and source records attributed to K L Koch.

At least 55 records · Page 3Linked to original sources
PubMed1990

Afferent loop obstruction presenting as acute pancreatitis and pseudocyst: case reports and review of the literature.

Afferent loop obstruction after gastrectomy and Billroth II reconstruction is an uncommon problem. Complete acute obstruction requires emergent laparotomy. However, chronic obstruction may begin insidiously and its symptoms may reflect other gastrointestinal diseases. Two patients are described who developed acute abdominal pain, marked hyperamylasemia, and palpable abdominal masses 5 and 15 years after Billroth II gastrectomy. The masses were initially interpreted as pancreatic pseudocysts. Both patients were found to have chronically obstructed afferent limbs, and in one the obstruction was associated with hundreds of stasis stones within the afferent limb. Surgical decompression was accomplished in each patient. Patients who have undergone Billroth II reconstruction have signs, symptoms, and laboratory findings consistent with acute pancreatitis. A history of previous gastrectomy, recurrent or severe abdominal pain, hyperamylasemia with characteristic tomography, and endoscopic findings will establish the diagnosis and necessitate surgical evaluation and intervention.

Acute Disease↗
PubMed1990

The effects of fixation and restricted visual field on vection-induced motion sickness.

Approximately 60% of healthy human subjects experience motion sickness when exposed to a rotating optokinetic drum. The purpose of the present study was to determine the effects of certain visual factors on susceptibility to motion sickness. Vection data (illusory self-motion), horizontal eye movement recordings, subjective motion sickness report, and a measure of gastric myoelectric activity (electrogastrogram, EGG) were obtained from 45 subjects, who were randomly divided into the following three groups: a control group that observed the entire visual field with no fixation, a group that fixated on a central target, and a third group that had a visual field restricted to 15 degrees. The experimental session was divided into the following three 12-min periods: baseline, drum rotation, and recovery. The results showed that fixation greatly reduced nystagmus and slightly reduced vection. The restricted visual field slightly reduced nystagmus and greatly reduced vection. Both of these manipulations significantly reduced symptoms of motion sickness and tachyarrhythmia, the abnormal gastric myoelectric activity that usually accompanies nausea.

Electromyography↗
PubMed1989

Recurrent autonomous esophageal peristalsis in patients with chest discomfort.

Routine esophageal manometry revealed a novel pattern of esophageal motility, recurrent autonomous peristalsis, in five patients evaluated for chest discomfort and heartburn. In the absence of swallowing, esophageal peristalsis occurred at frequencies of 4-8 peristaltic sequences per minute for periods of 2-8 min. The recurrent peristaltic sequences developed spontaneously during manometry and were associated with the onset of vague chest discomfort in four patients; one patient reported no symptoms during recurrent peristalsis. Duration and propagation velocity of the recurrent peristaltic contractions differed significantly from primary peristalsis in four patients. Recurrent autonomous esophageal peristalsis is an unusual motor pattern that may be associated with vague chest discomfort. The circuit(s) mediating recurrent autonomous peristalsis are unknown.

Adult↗
PubMed1989

Sham feeding. Cephalic-vagal influences on gastric myoelectric activity.

The effects of sham feeding on gastric motility of human subjects have not previously been studied. The amplitude of 3-cpm electrogastrogram (EGG) waves increases after the ingestion of food. We hypothesized that sham feeding would stimulate a similar, but briefer gastric myoelectric response. Healthy human subjects chewed and expectorated a hot dog on a roll and later ate a second hot dog. EGGs were continuously recorded before, during, and after sham feeding and eating. The results of experiment I (N = 27) showed that the hand-scored amplitude of the 3-cpm waves increased significantly (P less than 0.01) during sham feeding. Two minutes after sham feeding, the mean amplitude of 3-cpm EGG waves returned to baseline level. The increase in EGG amplitude during eating was also significant (P less than 0.01), and remained increased for approximately 30 min after ingestion. The procedure used in experiment II (N = 20) was similar to experiment I, but EGGs were computer analyzed and power, ie, spectral intensities, at 3 cpm were obtained. The increase in power at 3 cpm during sham feeding and during eating was significant (P less than 0.05 and P less than 0.02, respectively). Similar to experiment I, the duration of increase in power at 3 cpm was brief during sham feeding compared to the postprandial increase. Four vagotomized subjects failed to show an increase in power at 3 cpm in response to sham feeding. We conclude: (1) The cephalic-vagal stimulation of sham feeding increases briefly the amplitude and power of 3-cpm gastric myoelectric activity in healthy subjects but not vagotomized patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Esophageal dysfunction and chest pain in patients with mitral valve prolapse: a prospective study utilizing provocative testing during esophageal manometry.

PURPOSE: The cause of chest discomfort in patients with mitral valve prolapse (MVP) remains unknown. Our aim was to determine prospectively the incidence of esophageal disorders and abnormal responses to edrophonium chloride and esophageal acid infusions in patients with MVP and troublesome non-ischemic chest pain. PATIENTS AND METHODS: After coronary artery disease was excluded, 20 patients with MVP and chest pain underwent esophageal manometry and provocative testing with edrophonium chloride and acid infusion. Seven patients with MVP but without chest pain served as control subjects; they also underwent esophageal manometry with provocative testing. RESULTS: Esophageal manometry revealed esophageal disorders in 16 patients: diffuse esophageal spasm in 14 patients, nutcracker esophagus in one, and hypotensive lower esophageal sphincter in one. Esophageal motility was normal in four patients. Injection of edrophonium and acid infusion tests evoked typical chest discomfort in three of 18 and five of 19 patients, respectively. In six of seven control subjects with MVP but with no chest discomfort, esophageal motility was normal and provocative testing did not produce chest discomfort (p less than 0.05 versus results in patients). CONCLUSION: Esophageal disorders were common and may account for chest discomfort in certain patients with MVP and persistent chest pain syndromes.

Adult↗
PubMed1989

Motion sickness and gastric myoelectric activity as a function of speed of rotation of a circular vection drum.

Motion sickness symptoms and electrogastrograms (EGGs) were obtained from 60 healthy subjects while they viewed an optokinetic drum rotated at one of four speeds: 15, 30, 60 or 90 degrees.s-1. All subjects experienced vection, illusory self-motion. Motion sickness symptoms increased as drum speed increased up to 60 degrees.s-1; i.e., symptoms decreased at 90 degrees.s-1. Power, spectral intensity, of the EGG at the tachygastria frequencies (4-9 cpm) was calculated at each drum rotation speed since previous studies have shown a close correspondence between development of tachygastrias and motion sickness symptoms. Power at 4-9 cpm increased as a function of drum speed up to 60 degrees.s-1 and then decreased at 90 degrees.s-1. Power at 4-9 cpm and 60 degrees.s-1 was significantly greater than at 15 degrees.s-1. The correlation between the motion sickness symptoms and the power at 4-9 cpm was significant. Thus, drum rotation speed influenced the spectral power of the EGG at 4-9 cpm, tachygastria, and the intensity of motion sickness symptoms.

Adult↗
PubMed1989

Adaptation to vection-induced symptoms of motion sickness.

The visual-vestibular-proprioceptive sensory mismatch of vection provokes motion sickness in approximately 60% of healthy subjects. Approximately 60% of astronauts experience motion sickness in microgravity where vestibular/otolith function is altered. The purpose of this study was to determine the extent to which symptoms of motion sickness and tachygastria, an abnormal 4-9 cpm rhythm of the stomach, decrease or adapt during three repeated exposures to a rotating circular vection drum. Subjects sat in the drum for 45 min: 15 min baseline, 15 min drum rotation at 60 degrees.s-1, and 15 min recovery. Gastric myoelectric activity was continuously recorded with the electrogastrogram (EGG). Symptom reports were obtained during rotation. In Experiment I, 10 subjects were exposed to the drum 3 times with intersession intervals of 4-24 d. They failed to show adaptation based on subjective reports and all showed tachygastria. In Experiment II, 14 new subjects were exposed to the drum 3 times with intersession intervals of 48 h. The group experienced a reduction in symptoms and tachygastria with repeated exposure to the drum. Thus, symptomatic and physiological improvement occurred after training in subjects susceptible to vection-induced motion sickness. Preflight adaptation to visual-vestibular sensory mismatch may reduce motion sickness experienced in the environment of microgravity.

Adaptation, Physiological↗
PubMed1989

Gastric emptying and gastric myoelectrical activity in patients with diabetic gastroparesis: effect of long-term domperidone treatment.

We measured gastric emptying and gastric myoelectrical activity with solid-phase gastric-emptying tests and cutaneously recorded electrogastrograms (EGGs), respectively, in six insulin-dependent diabetic patients with nausea and vomiting who did not respond to standard treatments. Baseline solid phase gastric emptying was markedly delayed (78 +/- 8% retained at 120 min) and EGG recordings revealed gastric dysrhythmias; tachygastria (4-9 cpm signals) in one patient, 1- to 2-cpm waves in two patients, and flatline patterns in three patients. No patient had a normal 3-cpm EGG pattern. After 6 months of domperidone treatment, mean upper gastrointestinal symptoms scores decreased from 17.8 to 3.7 (p less than 0.01), and normal 3-cpm EGG frequencies were recorded from each of the six patients. The mean percentage of meal retained at 120 min decreased but did not improve significantly. Thus, establishment of normal 3-cpm gastric myoelectric activity and resolution of dysrhythmias, not normalization of emptying rates, was associated with improvement in upper gastrointestinal symptoms in these diabetic patients.

Adult↗
PubMed1988

Effects of acetylsalicylic acid on electromechanical activity of in vivo rabbit ileum.

Aspirin has antisecretory and ulcerogenic properties in the gastrointestinal tract. The aim of this study was to determine the effects of acetylsalicylic acid (ASA) on the electrical and mechanical activity of the ileum in anesthetized New Zealand White rabbits. Ileal electromechanical activity was recorded from serosal electrodes and a miniature intraluminal balloon. Thirty minutes after injection of ASA (30, 60 and 100 mg/kg intravenous) significant and dose-dependent increases in the percentage of slow waves with action potentials were observed when compared with saline-infected animals. The onset of action potentials correlated with phasic increases in intraluminal pressure, indicating the onset of circular muscle contractions. Injection of 15 mg/kg ASA, sodium salicylate (100 mg/kg intravenous) or saline had no effect on baseline action potential activity. Prostaglandin E2 (PGE2) (5 and 10 micrograms/kg intravenous) significantly increased slow-wave frequency and decreased ASA-induced action potential activity. This study demonstrates that (1) ASA, but not sodium salicylate, stimulates phasic ileal action potential and contractile activity and (2) in ASA-treated animals, PGE2 produces differential effects on in vivo slow-wave frequency and action potential activity.

Action Potentials↗
PubMed1987

Effect of barium meals on gastric electromechanical activity in man. A fluoroscopic-electrogastrographic study.

UNLABELLED: The relationship between the cutaneously recorded electrogastrogram (EGG) and gastric contractions in man is unclear. We investigated: (1) the relationship between the electrogastrogram (EGG) signals and gastric contractions elicited by barium meals and (2) the effects of barium meals on frequency and amplitude of EGG signals. As documented by fluoroscopy in four healthy subjects, barium meals stimulated three per minute gastric peristalsis which corresponded with simultaneously recorded three cycle per minute (cpm) EGG waves. Eighteen other healthy volunteers ingested 45% (w/v) or 60% barium suspensions. As determined by Fourier analysis, the dominant EGG frequency before barium was 3 cpm in 16 subjects; two subjects had no distinct frequency peaks. After barium ingestion, the mean amplitude or power at 3 cpm and 1 cpm increased, but the increase was significant only after 45% barium. IN CONCLUSION: (1) individual EGG waves after barium reflect gastric peristaltic sequences, which are reflected in increases in amplitude or power of 3 cpm EGG activity; (2) density or viscosity of the barium meal affects the gastric myoelectric response; and (3) mechanical correlates of 1 cpm EEG activity are unknown.

Adolescent↗
PubMed1987

Spectral analysis of tachygastria recorded during motion sickness.

The purpose of the present experiment was to study frequency changes in gastric myoelectric activity of healthy human subjects and the development of symptoms of motion sickness as brought about by vection or illusory self-motion. Fifteen fasted healthy human subjects were seated inside a circular vection drum, the rotation of which produces visual signals of self-motion that are in conflict with vestibular signals (i.e., mismatched sensory input). An electrogastrogram was obtained for three 15-min. periods: baseline, rotation, and after drum rotation stopped. Respiration, symptoms volunteered by subjects, and a continuous measure of intensity of symptoms were recorded. Five subjects showed a continuation of normal 3-cycles/min. activity during drum rotation and reported no symptoms of motion sickness. Ten subjects showed a shift of their dominant gastric frequency from 3 cycles/min. to 4-9 cycles/min. during drum rotation and reported symptoms of motion sickness. Running spectral analysis revealed a close correspondence over time between tachygastria and reports of symptoms of motion sickness.

Adult↗
PubMed1987

Crohn's disease and massive lower gastrointestinal bleeding: angiographic appearance and two case reports.

Massive lower gastrointestinal bleeding is described in two patients with Crohn's disease. In case 1, extravasation of contrast material from the ileal branch of the ileocolic artery was seen during selective angiography. In case 2, results of an in vitro labeled 99Tc pyrophosphate red blood cell scan localized bleeding to the ileum. In both cases, medical management was unsuccessful, and surgical resection of the affected bowel was required to stop the bleeding. Angiographic appearance of Crohn's disease is discussed, and a review of the literature of this unusual feature of Crohn's disease is presented.

Adult↗
PubMed1986

Dose-response effects of indomethacin and PGE2 on electromechanical activity of in vivo rabbit ileum.

We determined dose-response characteristics of indomethacin and prostaglandin E2 on the myoelectric activity in ileum of anesthetized New Zealand White rabbits. Monopolar electrodes and an intraluminal saline-filled catheter were used to simultaneously record electrical and mechanical activity. Thirty minutes after injection of 3.0, 5.0, and 10.0 mg/kg indomethacin, the percentage of slow waves with action potentials increased significantly from 10% to over 80%; at 60 min action potential activity decreased but remained dose dependent and significantly greater than controls. Action potential activity correlated with phasic increases in intraluminal pressure. Low-dose indomethacin (1.5 mg/kg) did not significantly alter action potential activity. Action potential activity induced by indomethacin (5 mg/kg) decreased dose dependently after infusion of prostaglandin E2 (PGE2, 1-28 micrograms/kg). In summary, dose-dependent action potential activity was induced by indomethacin and reversed by PGE2. Endogenous inhibitory prostaglandins (PGE2 or others) appear to modulate activity of specific excitatory neuromuscular circuits in in vivo ileum.

Action Potentials↗
PubMed1986

Esophageal disorders in patients with chest pain and mitral valve prolapse.

The origin of chest discomfort in patients with mitral valve prolapse is controversial. We performed esophageal manometry in 18 patients with mitral valve prolapse, chest pain, and no significant coronary artery disease at cardiac catheterization. Fourteen of the 18 had esophageal disorders: five had diffuse esophageal spasm and two had hypertensive lower esophageal sphincter-motility disorders associated with chest pain syndromes; five mitral valve prolapse patients had hypotensive lower esophageal sphincters, a finding that increases the probability of symptomatic gastroesophageal reflux; and two had nonspecific motor abnormalities. Esophageal disorders may provide an explanation for chest discomfort experienced by certain patients with mitral valve prolapse.

Adult↗
PubMed1986

Chest pain associated with mitral valve prolapse. Evidence for esophageal origin.

The cause of chest pain associated with mitral valve prolapse remains unclear. A young woman with chest pain ascribed to mitral valve prolapse is described. Response of chest discomfort to atenolol therapy had been poor. The patient's chest discomfort and concomitant esophageal spasm were provoked by intravenous infusion of edrophonium chloride during esophageal manometry. A Bernstein acid infusion test also induced her chest pain. Review of systems revealed intermittent dysphagia and postprandial heartburn. In certain patients with mitral valve prolapse, esophageal motility disorders may be the cause of chest discomfort.

Adult↗