Pregnancy-related changes in small intestinal myoelectric activity in the rat

To determine if changes in intestinal motility occur during pregnancy, we studied small intestinal myoelectric activity, using monopolar electrodes, in fasted pregnant rats from day 12 to day 18 of the 22-day gestation period. We also studied fasting myoelectric activity in postpartum, nonpregnant, and castrate females. In all rats, the interdigestive myoelectric complex was invariably present with recurring activity fronts appearing at the proximal electrode and moving slowly abroad. Intervals between fronts were similar in all four groups, ranging from 12.61 min to 14.58 min. In pregnant rats, however, there was loss of the periodicity characteristic of activity fronts in the other groups; intervals up to 43 min in length were occasionally noted. Unorganized, randomly occurring spike potentials characterized these intervals. The average coefficient of variation of interval length was significantly (p less than 0.05) greater in pregnant rats (0.401) than in castrate (0.197) and nonpregnant rats (0.248). These studies confirm the presence in rats of pregnancy-related changes in small intestinal myoelectric activity.

Hepatic angiosarcoma associated with short-term arsenic ingestion

In a 45 year old man, hepatic angiosarcoma developed 33 years after medicinal arsenic ingestion of only six months' duration. In addition, the patient had a history of basal cell carcinomas without having had excessive sunlight exposure. Factor VIII staining of the tumor supports an endothelial cell origin of the tumor. The development of skin cancers and hepatic angiosarcoma in this patient suggests that there may be no safe threshold of arsenic exposure. A careful history concerning even short-term arsenic exposure in all patients with hepatic angiosarcoma may uncover more examples of this association.

Effect of pregnancy on gastrointestinal transit

In order to evaluate the possible effects of pregnancy-associated sex steroids on gastrointestinal function, we determined gastrointestinal transit times and sex steroid levels in 15 women during the third trimester of their pregnancies and again 4--6 weeks following delivery when gastrointestinal function had symptomatically returned to normal. Gastrointestinal transit time from ingestion of a liquid lactulose meal to its delivery to the cecum was determined by monitoring breath hydrogen concentrations at 10-min intervals. Gastrointestinal transit times were significantly prolonged in the third trimester of pregnancy, when progesterone and estradiol levels were increased, compared to the postpartum period. This study supports previous findings which suggest that increasing levels of progesterone and estradiol affect gastrointestinal function and therefore may contribute to gastrointestinal symptoms that often occur in pregnant women.

Preparing anesthesia equipment for suspected malignant hyperthermia episodes

Malignant hyperthermia is a relatively rare condition which strikes susceptible patients undergoing surgery. This disorder is an inherited biochemical defect, triggered by certain anesthetic agents and stress. The patient suffers a rapid and potentially dangerous rise in temperature, brought about by an increase in metabolism. If a patient, by family history or test, is suspected of being susceptible to malignant hyperthermia, special precautions must be taken before proceeding with surgery. The clinical engineer must: 1) prepare special anesthesia equipment which is free of trace gases capable of triggering an episode of malignant hyperthermia; 2) provide special monitoring facilities to detect the onset of an episode; and 3) have treatment facilities on hand in the event that an episode does develop.

Stimulation of gastric acid secreted by glycine and related oligopeptides in humans

To investigate the effect of oligopeptides on gastric secretion in humans, we investigated acid secretion in healthy volunteers after the intragastric infusion of physiological saline, glycine (100 mM), diglycine (50 mM), triglycine (33 mM), and tetraglycine (25 mM). All test solutions were equivalent in glycine content, osmolality (300 mosmol), and pH (5.5). Although the rate of acid secretion was greater during glycine than saline infusion [5.6 +/- 0.8 vs. 3.3 +/- 1.1 mmol/h (means +/- SE); P less than 0.05], the rate of acid secretion during glycine infusion was not significantly different from that induced by its related peptides. There were increases in plasma glycine concentration during infusion of glycine and its related peptides but no detectable changes in serum gastrin levels. The increases in plasma glycine must have been due to absorption from the small intestine because there was no gastric absorption of glycine in free or dipeptide form nor diglycine hydrolysis in the stomach. Therefore, our results permit implicating only the increased plasma glycine concentrations as the stimulus for acid secretion by glycine and its homologous peptides.

Lactose malabsorption in recurrent abdominal pain of childhood

In order to evaluate the role of lactose malabsorption in children with recurrent abdominal pain, we performed a prospective controlled double-blinded study in 40 children with RAP of at least three months' duration. Children were studied for lactose malabsorption by breath hydrogen determinations after ingestion of lactose (2 gm/kg of body weight; maximum 50 gm). Lactose malabsorbers were retested with 12.5 gm lactose; lactose absorbers were retested with lactose for ability to produce hydrogen. All children underwent a dietary trial which included two lactose elimination periods. Although 12 children (30%) were lactose malabsorbers, only three malabsorbed part of the smaller, more physiologic, lactose load. Improvement rates of lactose malabsorbers and absorbers during lactose elimination were not significantly different as judged by their physicians and as determined by a 50% or more decrease in pain frequency. These results suggest that lactose malabsorption is of little importance in children with RAP.

Comparative sensitivity of eight- and 24-hour bile acid breath tests and Schilling test in ileopathies

The conventional eight-hour bile acid breath test ("acute measurements"), was compared with a modified, extended, 24-hour breath test ("ratio measurements") and the Schilling test to assess relative sensitivity in detecting ileal dysfunction. Sixty-four patients with ileopathies were studied. The presence or absence of bile acid malabsorption was documented by fecal excretion studies of bile acid labels. The sensitivity of the "acute measurements" in the breath test was not significantly different from that of the "ratio measurements" in the ileopathies, regardless of whether or not bile acid malabsorption was present. The "acute measurements" were positive in 49 (77%), the "ratio measurements" in 54 (84%) and the Schilling test in 49 (77%) of the patients. In about 30%, bile acid breath test and Schilling test were not positive in the same patient. A combination of "acute measurements" (breath test) and Schilling test increased the percentage of cases with at least one positive test to 91%. The results of the study show: 1. The sensitivity of the bile acid breath test does not increase if 14CO2 measurements are carried out beyond eight hours. 2. Although the breath test and Schilling test are of similar sensitivity in ileopathies, they are frequently not positive in the same patient. Therefore, it would be clinically useful to combine both tests in order to increase the likelihood of diagnosing ileal dysfunction.

Biofeedback therapy for fecal incontinence

Twenty-five patients (ages 10 to 79 years; average, 48 years) with fecal incontinence underwent anorectal manometry with a three-balloon system connected to a physiograph. On a basis of manometric criteria showing the presence of rectal sensation, 17 patients underwent biofeedback conditioning. Underlying disorders included irritable bowel syndrome, diabetes mellitus, anal sphincter damage from surgery or disease, and neurogenic anal dysfunction. Twelve of the 17 patients who received biofeedback training had significant improvement in bowel soiling. Follow-up periods ranged from 2 to 38 months (mean, 15 months). There were no significant differences in threshold of rectal sensation, relaxation of the internal anal sphincter, and pre- and postbiofeedback thresholds of external anal sphincter contraction between responders and nonresponders. Minimal criteria for successful treatment appeared to be ability to sense rectal distension, good motivation, and absence of significant psychological dysfunction. Biofeedback conditioning is a simple and effective technique in the treatment of selected patients with fecal incontinence.

Use of biofeedback in treatment of fecal incontinence in patients with meningomyelocele

Fourteen children (aged 5 to 17 years) with meningomyelocele and significant fecal soiling underwent anorectal manometry using a three-balloon system connected to a physiograph. On the basis of manometric criteria demonstrating some rectal sensation, eight patients were treated with biofeedback conditioning. Patients were taught to contract the external and sphincter or nearby gluteal muscles in response to various volumes of rectal distention. Four of the eight patients who were treated with biofeedback had a good clinical response with disappearance of soiling or a greater than 75% improvement in the frequency of soiling. Follow-up periods ranged from three to 12 months. The minimum criteria for successful treatment appeared to be normal threshold of rectal sensation and ability to contract gluteal or related muscles. Anorectal manometry is a rapid, easily obtained test that can identify those children with meningomyelocele and fecal incontinence who may benefit from biofeedback conditioning. Biofeedback is a simple, safe, and effective technique in the treatment of certain children with fecal soiling due to neurogenic anal sphincter dysfunction.

Automatic noninvasive blood pressure monitors: analog/manual adaptation of Dinamap (TM)

This paper describes some of the features and limitations of the newly-developed, automatic, noninvasive blood pressure monitors. In particular, an analog/manual modification is presented which can be adapted to a variety of such devices. The manual/automatic adaptation of the Critikon Dinamap (TM) blood pressure monitor is specifically described. This modification provides continuous observation of cuff pressure and permits the option of manual cuff inflation and deflation. The analog/manual adaptation is useful in special patient conditions and as a teaching aid.

Evidence refuting a role for increased abdominal pressure in the pathogenesis of the heartburn associated with pregnancy

As a model of pseudopregnancy, the lower esophageal sphincter pressure and plasma gastrin and basal gastric pH levels were determined before and after diuresis in 10 men with tense ascites due to cirrhosis of the liver. Prior to diuresis, when abdominal pressure was increased, sphincter pressure was increased. After diuresis, when ascites was no longer a clinical problem, sphincter pressure was normal. None of the men had heartburn or demonstrable acid reflux either before or after diuresis. In addition, no differences in basal fasting levels of gastrin or gastric pH were noticed before and after diuresis. This study refutes a role for increased abdominal pressure due to an enlarging uterus in the pathogenesis of the heartburn of pregnancy. Moreover, it is consistent with those studies which suggest that increasing progesterone levels seen during pregnancy induce a loss of basal lower esophageal sphincter pressure and thereby allow the occurrence of acid reflux which produces symptomatic heartburn.

Gastrointestinal transit: the effect of the menstrual cycle

Gastrointestinal transit time as well as serum estradiol and progesterone levels were measured in 15 normally menstruating women twice during their menstrual cycle, once in the follicular phase (days 8-10) when progesterone levels are low and once in the luteal phase (days 18-20) when progesterone levels are increased. Each subject had a progesterone rise during the luteal phase and onset of menses at the expected time documenting ovulatory cycles. Gastrointestinal transit time from ingestion of lactulose to the delivery of the disaccharide to the cecum was determined by monitoring breath hydrogen levels at 10-min intervals. Gastrointestinal transit time was significantly (p less than 0.01) prolonged in the luteal phase when progesterone levels were increased compared with the follicular phase. This study demonstrates that the menstrual cycle plays an important role in determining the gastrointestinal transit time in normally menstruating women.

Amyloidosis and chronic intestinal pseudoobstruction

A 39-year-old woman with multiple myeloma developed chronic intestinal pseudoobstruction associated with gastrointestinal amyloidosis. Motor abnormalities of the lower esophageal and anal sphincters correlated closely with amyloid infiltration in affected areas. Manometric abnormalities of esophageal and anal sphincter function may provide indirect evidence of amyloid deposition of gastrointestinal smooth muscle in an appropriate clinical setting.

Chronic headache in the shunt-dependent adolescent with nearly normal ventricular volume: diagnosis and treatment

The shunt-dependent adolescent will occasionally manifest shunt malfunction by intermittent or chronic headache without any obvious signs of increased intracranial pressure (ICP). A small percentage of these patients will have nearly normal ventricular volume, making the diagnosis and treatment difficult. The authors present a comprehensive approach to this problem that uses computerized axial tomography (CT), ICP monitoring, positive contrast or isotope shunt scan, shunt revision, subtemporal craniectomy, or medical management as the individual situation dictates. The CT scan identifies patients with nearly normal ventricular volume. ICP monitoring then determines whether there is shunt malfunction. The shunt scan aids in localization of the malfunction. For distal obstruction, a simple revision is performed. When proximal shunt malfunction occurs, either subtemporal craniectomy or revision is carried out. It has been documented that occasionally ICP is episodically increased in the absence of shunt malfunction. This is secondary to abnormal brain compliance, and subtemporal craniectomy alone or in conjunction with corticosteroids is curative. This comprehensive approach is designed to provide a method for recognizing and treating intermittently increased ICP in the shunt-dependent child.

Kaolin-induced hydrocephalus impairs CSF secretion by the choroid plexus

CSF volume flow and sodium (Na+)-influx rates in normal and kaolin-induced hydrocephalic cats were measured during ventricular perfusion with anisotonic sucrose solutions. When ventricular fluid osmolality was 120 mOsm, CSF volume flow ceased for both groups of cats. As ventricular fluid osmolality was increased, the CSF volume flow rate of normal cats increased to 70 microliter per minute, and in hydrocephalic cats to 40 microliter per minute. In normal cats, for ventricular fluid osmolality between 50 and 350 mOsm, Na+-influx was constant and thought to occur by diffusion; while for higher osmolalities, Na+-influx increased. In hydrocephalic cats, Na+-influx increased over the entire range of ventricular osmolality but was less than in normal cats. Acetazolamide decreased the CSF volume flow in normal cats by 40 percent, but was ineffective in hydrocephalic cats. These results suggest that CSF secretion by the choroid plexus of cats with kaolin-induced hydrocephalus is impaired.

Evidence for the movement of fluid, macromolecules and ions from the brain extracellular space to the CSF

This report examines the effect of decreasing serum osmolality on movement into the ventricular system of fluid and of test material injected into the brain. Trace quantities of 22NaCl and 125I-labeled cat serum albumin (CSA) were injected into cerebral white matter of cats. The rates of cerebrospinal fluid volume flow, and appearance of 22Na and 125I-CSA were measured in the effluent fluid using ventriculocisternal perfusion before and while serum osmolality was acutely decreased by the intravenous infusion of a 60 mOsm sucrose solution. As compared to the control period, at the end of the infusion serum osmolality decreased from 321 +/- 4.2 mOsm to 283 +/- 4.0 mOsm and CSF volume flow increased from 21.8 +/- 2.3 microliter/min to 54.9 +/- 4.1 microliter/min (means +/- S.E.). The slope of the regression line describing 22Na influx went from 1.04 to 1.79, while for 125I the slope went from 0 to 1.38. These results suggest that a common pathway may exist for the movement, through the brain and into the ventricular system, of water, ions and large molecules.

Suppressed murine mammary tumor virus (MuMTV) expression in RIII female mice treated neonatally with goat antiserum to MuMTV

Passive immunization of newborn inbred RIII (R3) mice with the globulin fraction of goat antiserum to murine mammary tumor virus (MuMTV) successfully suppressed MuMTV expression in the milk of some of the treated mice throughout nine successive lactations. No mammary tumors developed in the MuMTV-suppressed mice during the first 9 months, whereas all untreated R3 female breeders expressed MuMTV in the milk of the third lactation, and all developed tumors before 9 months of age (mode and median: 189 days).

An animal model for the production of intracranial pressure plateau waves

This communication describes a reproducible model for the generation of intracranial pressure plateau waves by obstructing the spinal cord central canal of cats with experimentally induced hydrocephalus.

Effect of indomethacin on cholera-induced fluid movement, unidirectional sodium fluxes, and intestinal cAMP

Cholera enterotoxin (CT) produces intestinal secretion associated with an elevation of intestinal cyclic AMP (cAMP). Indomethacin, a potent inhibitor of prostaglandin (PG) synthesis, decreases CT-induced secretion, although a role for PG in this process has not been demonstrated. The purpose of this study was to measure the effects of indomethacin on net fluid movement and unidirectional Na fluxes in rabbit jejunal loops exposed to CT and to correlate these findings with intestinal cAMP levels. In untreated animals (no indomethacin), CT loops secreted 0.37 ml per cm per 4 hr compared to absorption in control loops of 0.23 ml per cm per 4 hr (P less than 0.001). In indomethacin-treated animals, there was a striking reduction of secretion in CT loops (0.07 ml per cm per 4 hr, P less than 0.001). Absorption in control loops in indomethacin animals was greater than in untreated animals (0.42 ml per cm per 4 hr, P less than 0.02). Unidirectional Na fluxes were greatly depressed in indomethacin animals at 1 h in both CT and control loops. This effect disappeared by 4 hr. Intestinal cAMP levels in CT loops, although not elevated at 1 hr despite the onset of secretion, were significantly elevated at 4 hr. Indomethacin did not alter cAMP levels at 1 and 4 hr in either cholera or control loops. These studies support the view that PG synthesis is not involved in CT-induced elevation of intestinal cAMP. Indomethacin may depress intestinal secretion by inhibiting a PG-mediated step beyond the generation of cAMP or by acting on some other, as yet unidentified, biological mechanism involved in intestinal secretion.

Sodium exchange between blood, brain, and CSF in normal and hydrocephalic cats

The exchange of sodium between blood, brain, and cerebrospinal fluid was studied in normal and kaolin-induced hydrocephalic cats. The ventricles were perfused to measure fluid formation and Na+ exchange rates. 22Na was added to the perfusion fluid or injected intravenously as a tracer for Na+ movement. Na+ and 22Na were also measured in cortical gray and white matter. Na+ relative specific activities were calculated for brain, effluent fluid, and serum. With 22Na in the perfusion fluid, Na+ exchange was not different from nascent Na+ influx for both normal and hydrocephalic cats. Na+ relative specific activities of cortical gray and white matter were 10 times greater in hydrocephalic than in normal cats. This difference in Na+ relative specific activity for brain may be due to a higher diffusion constant or to a lower brain capillary permeability. When 22Na was given intravenously, the Na+ diffusional exchange for normal cats was less than that measured when 22Na+ was in the perfusion fluid. In hydrocephalic cats, the Na+ diffusional exchange was effectively zero. Na+ relative specific activities of cortical gray and white matter were the same for normal and hydrocephalic cats. These findings suggest that the impaired Na+ diffusional exchange may be due to pathological changes in the choroid plexus.

On the movement of fluid through the brain of hydrocephalic cats

The effects of changes in serum osmolality on the volume flow of fluid into the cerebral ventricles and on brain water content was examined in cats with kaolin-induced hydrocephalus. Slopes of the regression lines relating volume flow and serum osmolality for both normal and hydrocephalic cats are the same. The constant difference in flow rates between the two lines, 7 mul per minute, is probably due to impaired choroid plexuow rates between the two lines, 7 mul per minute, is probably due to impaired choroid plexus function of the hydrocephalic cats. The osmotic pressure gradient that causes the flow of fluid is therefore probably between blood and brain. Under these conditions changes in brain water content of hydrocephalic cats were smaller than in normals and can be related to the edema present in this disorder. Despite the inflammatory response to kaolin, the blood-brain barrier remains intact. From the calculated filtration coefficient, it can be inferred that the flow of water from serum through brain and into cerebrospinal fluid is limited by the resistance of fluid flow through the brain.

Effect of caffeine on the human small intestine

Methylxanthines produce intracellular accumulation of cyclic 3'5'-AMP (cAMP) by inhibition of phosphodiesterase and mucosal cAMP accumulation. Cyclic AMP is thought to mediate small intestinal secretion caused by some enterotoxins, hormones, and methylxanthines. These studies were designed to evaluate the effect of caffeine on small intestinal net fluid movement and transit times. The administration of caffeine in amounts ordinarily contained in many beverages and medications (75 to 300 mg) resulted in striking net secretion in the jejunum which lasted at least 15 minutes. This occurred in six of seven studies. Baseline net absorption of 0.5 ml per cm per hr was reversed to net secretion of 6.0 +/- 2.2 ml per cm per hr after oral caffeine ingestion (P less than 0.01). Net secretion also occurred in the ileum in seven of eight studies, but the onset of secretion appeared 35 min later than in the jejunum. These patterns of secretion correlated best with the passage of the intestinal bolus of caffeine rather than plasma caffeine levels. In contrast to other net secretory conditions, which increase the speed of transit, small intestinal transit times, as determined by dye dilution methods, were unchanged by caffeine. It is possible that methylxanthine-induced small intestinal secretion may play a role in the symptoms experienced by some patients with functional diarrhea.

The effects of ventricular fluid osmolality on bulk flow of nascent fluid into the cerebral ventricles of cats

The effects of ventricular fluid osmolality on the bulk flow of nascent fluid into the cerebral ventricles of anesthetized cats was measured during ventriculocisternal perfusion. This nascent fluid consists of both cerebrospinal fluid (CSF) and fluid which results from an osmotic gradient between ventricular fluid and the blood and/or brain. Perfusions were carried out with both mock CSF and with solutions containing either sucrose, urea, or NaCl. Differences between the normal bulk flow rate of nascent CSF and bulk flow rate measured during perfusion with anisotonic solutions were linearly related to corresponding differences in osmolality of the effluent fluid from the ventricles. The coefficients of somotic flow using sucrose (0.231 mul/min per mOsm) and NaCl (0.224) were similar, and greater than that using urea (0.156). During perfusion with sucrose when effluent osmolality increased by 200 mOsm (63% of normal), bulk flow rate of nascent fluid increased by 50 mul/min (200% of normal). Flow was undetectable when the effluent osmolality was 190 mOsm (decrease of 135 mOsm), although osmotically active particles continued to enter the ventricular system. Intravenous injection of acetazolamide reduced these coefficients to similar values of 0.0963 for NaCl, and 0.0955 for urea. In all experimental conditions no changes were found in cerebral water content. These results suggest that the increased bulk flow which occurs during perfusion with hypertonic solutions originates from the choroid plexus.

The sink action of cerebrospinal fluid volume flow. Effect on brain water content

Effects of changes in serum osmolarity on volume flow of fluid into the cerebral ventricles of cats were measured by ventriculocisternal perfusion with mock cerebrospinal fluid (CSF), mock CSF containing acetazolamide, or a 30 mOsm/liter sucrose solution. Serum osmolarity was altered by intravenous infusion of a sucrose solution ranging between 10 and 650 mOsm/liter changing volume flow. For all perfusion fluids, regression lines relating volume flow to infused solution osmolarity were parallel. After infusion of a 10 mOsm/liter solution, brain water content increased. One hour after infusion, volume flow returned to normal, although serum was still hypotonic. Gray matter water content was still elevated; white matter returned to normal. The results suggest that the source of increased volume flow is the brain, and that the CSF acts as a sink, limiting excess water accumulation during water intoxication.

Effects of changes in serum osmolarity on bulk flow of fluid into cerebral ventricles and on brain water content

The effects of changes in serum osmolarity on the rate and osmolarity of bulk flow of fluid into the cerebral ventricles and on cortical white and grey matter water content were studied in cats. Bulk flow rates and osmolarities were measured during ventriculocisternal perfusion both before and after intravenous infusion of glucose solutions. Infusions of glucose in concentrations greater than 6% decreased fluid bulk flow rate and its osmolarity. Glucose in concentrations less than 6 percent increased fluid bulk flow rate and decreased its osmolarity. Bulk flow rate and serum osmolarity were found to be linearly related with a coefficient of osmotic flow of minus 0.835 mul/min per mOsm/l. At the extremes of induced serum osmolarities, (290 and 360 mOsm/l) bulk flow rate was either increased by 120 percent or completely inhibited. Effluent osmolarity also increased proportionately to serum osmolarity (0.338 mOsm/l per mOsm/l). When compared to controls, cortical grey and white matter water content increased by 1.9 percent and 2.9 percent, respectively, when the infused glucose concentration was 2.5 percent or less, and decreased by 1.8 percent and 2.9 percent when the concentration was 10 percent or more. The results of these experiments suggest that the increased bulk flow comes from the brain, rather then directly from the blood.

The role of fiberoptic endoscopy in the diagnosis and management of duodenal neoplasms

This is a study of 11 cases of duodenal tumors encountered in 1200 consecutive duodenoscopic examinations over a 34-month period at The Johns Hopkins Hospital. Of these tumors, 4 were benign and 7 malignant. Endoscopic removal of 2 benign tumors was accomplished without morbidity and obviated the necessity for transabdominal surgery. The 2 other benign tumors were a probable lipoma and a benign polyp, and did not require surgical intervention. In 6 of the 7 patients with malignant lesions, the indication for performing duodenoscopy was an abnormal roentgenographic study. In each case, direct visualization of the abnormal area, together with biopsy and cytologic brushing, provided a definitive diagnosis of malignant disease and helped plan the therapeutic course. In the seventh patient, a primary adenocarcinoma at the duodenojejunal junction was found on endoscopic examination, after all other available diagnostic studies to find the cause of persistent gastrointestinal bleeding had been exhausted. Although duodenal tumors are not common, they were encountered in 1 of every 100 duodenoscopies at a referral center. With increasing use of fiberoptic endoscopy, such tumors will undoubtedly be seen with increasing frequency. In our experience, endoscopy has proved to be a safe and reliable method of distinguishing between benign and malignant duodenal neoplasms and of assistance in planning subsequent management.