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Biomedical subjects

R C Lange

Publications and source records attributed to R C Lange.

At least 55 records · Page 3Linked to original sources
PubMed1986

Effects of morphine and naloxone on esophageal motility and gastric emptying in man.

We studied the effect of morphine and naloxone on lower esophageal sphincter pressure, esophageal contraction amplitude, and gastric emptying of solids and liquids in ten normal healthy subjects. Morphine sulfate in a dose of 8 mg intravenous bolus significantly decreased sphincter pressure with a maximum fall of 22.8% of the basal tone. Naloxone, 5 mg intravenous bolus, resulted in a 20% increase in the baseline pressure. There was no change in the esophageal contraction amplitude, duration, or frequency of peristalsis with either morphine or naloxone. Gastric emptying was measured using a dual-isotope technique to simultaneously assess the emptying rates of both solid and liquid meal components. Morphine, 8 mg intravenous bolus, led to a significant inhibition (P less than 0.05) of the gastric emptying of both solids (99mTc sulfur colloid-labeled chicken liver) and liquids (111In DTPA-labeled water). Naloxone, 5 mg intravenous bolus, accelerated the gastric emptying of both solid and liquid components, but this did not achieve statistical significance. These observations suggest that: morphine's inhibitory effect on gastric emptying and lower esophageal sphincter pressure may contribute to its potent emetic properties; the human lower esophageal sphincter and stomach may have opiate receptors and further investigations should be addressed to determining if endogenous opiates play a role in the modulation of sphincter pressure and gastric emptying in humans.

Adult↗
PubMed1985

Effect of nifedipine on gastric emptying in normal subjects.

We studied the effects of the calcium-channel blocker, nifedipine, on solid and liquid phases of gastric emptying in 10 healthy male volunteers. Each subject underwent a dual-isotope radionuclide gastric emptying determination with and without the preadministration of nifedipine, 30 mg orally, given 20 min prior to ingestion of the test meal over 10 min, following which the subject lay supine under the gamma-counter for 2 hr. Blood samples for measurement of plasma nifedipine concentration were obtained at the time of drug administration and every 30 min throughout the gastric emptying determination. There was a threefold variation in the areas under the plasma nifedipine concentration vs time curve (AUC) obtained in these 10 subjects. Percent gastric retention of either the liquid (water) or the solid (chicken liver) marker was not significantly different after 30 mg oral nifedipine, as compared to the nontreatment day. We concluded that plasma nifedipine concentrations previously reported to be associated with significant esophageal motility effects in humans were not associated with effects on gastric emptying of either liquids or solids.

Adult↗
PubMed1985

Vascular thrombosis in acute hepatic allograft rejection: scintigraphic appearance.

Hepatobiliary imaging with 99mTc diisopropyl iminodiacetic acid was employed serially in a patient with an hepatic allograft, in order to follow the function of the transplant. Initially improving liver uptake and biliary excretion was observed; however, 12 days postoperative with clinical deterioration the scintigrams revealed an absence of uptake ("phantom" liver), due to thrombosis of the hepatic artery related to acute rejection. Hepatobiliary imaging can be helpful in the study of hepatic allografts.

Biliary Tract↗
PubMed1984

Delayed hemorrhagic infarction. A cause of late neonatal germinal matrix and intraventricular hemorrhage.

Although a single perinatal or postnatal event may be directly correlated to intraventricular hemorrhage (IVH) in some infants, in other infants IVH may be related to a series of insults. Asphyxia, hypotension, and a pressure-passive low cerebral blood flow (CBF) may lead to an infarction. Subsequent events known to cause sudden rises in the CBF may then produce a hemorrhage into damaged tissues. We report two cases of this proposed model for delayed hemorrhage into infarcted tissues, or late IVH. Both neonates were severely asphyxiated, and both experienced profound hypotension and a low CBF on the first postnatal day. Late IVH was found in both neonates; at 2 to 3 months of age, one neonate was found to have computed tomographic evidence for diffuse encephalomalacia, and the other neonate was noted to have an occipital porencephalic cyst.

Cerebral Hemorrhage↗
PubMed1984

Intraventricular hemorrhage in the preterm neonate: timing and cerebral blood flow changes.

Serial cranial ultrasound studies, 133xenon inhalation cerebral blood flow determinations, and risk factor analyses were performed in 31 preterm neonates. Contrast echocardiographic studies were additionally performed in 16 of these 31 infants. Sixty-one percent were found to have germinal matrix or intraventricular hemorrhage. Seventy-four percent of all hemorrhages were detected by the thirtieth postnatal hour. The patients were divided into three groups: early GMH/IVH by the sixth postnatal hour (eight infants) interval GMH/IVH from 6 hours through 5 days (10), and no GMH/IVH (12). Cerebral blood flow values at 6 postnatal hours were significantly lower for the early GMH/IVH group than for the no GMH/IVH group (P less than 0.01). Progression of GMH/IVH was observed only in those infants with early hemorrhage, and these infants had a significantly higher incidence of neonatal mortality. Ventriculomegaly as determined by ultrasound studies was noted equally in infants with and without GMH/IVH (50%) and was not found to correlate with low cerebral blood flow. The patients with early hemorrhage were distinguishable by their need for more vigorous resuscitation at the time of birth and significantly higher ventilator settings during the first 36 postnatal hours, during which time they also had higher values of PCO2. An equal incidence of patent ductus arteriosus was found across all of the groups. We propose that early GMH/IVH may be related to perinatal events and that the significant decrease in cerebral blood flow found in infants with early GMH/IVH is secondary to the presence of the hemorrhage itself. Progression of early GMH/IVH and new interval GMH/IVH may be related to later neonatal events known to alter cerebral blood flow.

Blood Flow Velocity↗
PubMed1983

Effect of metoclopramide on normal and delayed gastric emptying in gastroesophageal reflux patients.

Gastric emptying has an important role in the pathophysiology of gastroesophageal reflux disease. We investigated the effect of metoclopramide, a gastric prokinetic agent, in gastroesophageal reflux patients with normal as well as delayed emptying. Twenty-six patients with subjective and objective evidence of gastroesophageal reflux ingested an egg salad sandwich meal labeled with 99mtechnetium-DTPA for a baseline study, and then again on a separate day after receiving oral metoclopramide, 10 mg, 30 min prior to the test meal. The mean percent isotope remaining in the stomach after 90 min improved significantly (P less than 0.001) from 70.3 +/- 3.9% (SEM) to 55.2 +/- 4.2% after metoclopramide. Fourteen (54%) had a basal emptying in the normal range of 34-69% retention of isotope at 90 min, (means +/- 2 SD), while it was slow in 12 (46%). For those with delayed basal gastric emptying, the mean retention of 88.9 +/- 2.9% at 90 min was significantly (P less than 0.005) decreased by metoclopramide to 68.6 +/- 6.1%. In those patients with a normal basal gastric emptying and a mean retention of 54.4 +/- 2.3% at 90 min, there was also significant improvement (P less than 0.025) to 43.6 +/- 3.6% after metoclopramide. These data indicate that metoclopramide increased gastric emptying in gastroesophageal reflux patients with normal as well as delayed gastric emptying. Therefore on a patient management level a trial of metoclopramide is warranted in patients with gastroesophageal reflux disease and is not limited by the gastric emptying status of the patient.

Analysis of Variance↗
PubMed1983

Postpartum perfusion of the preterm brain: relationship to neurodevelopmental outcome.

Bayley developmental assessments were performed at 12 months corrected age on 11 preterm infants, all of whom had undergone 133-Xenon cerebral blood flow measurements (CBF) on the 1st day of life and neonatal computerized tomography scans for the detection of intraventricular hemorrhage. The Bayley mental index was found to vary as a quadratic function of CBF to the left hemisphere, with moderate CBF values associated with more favorable outcomes than either low or high CBF values.

Cerebral Hemorrhage↗
PubMed1983

Radionuclide esophageal emptying of a solid meal to quantitate results of therapy in achalasia.

In this study we evaluated esophageal emptying using an isotope-labeled solid meal (an egg salad sandwich labeled with 99mTc-sulfur colloid) and compared it with lower esophageal sphincter pressure and a graded symptom score in the assessment of treatment in achalasia. Twenty-nine achalasic patients had lower esophageal sphincter pressure and esophageal emptying measured before treatment. Emptying at 5 min in the achalasic patients was significantly delayed, compared with normals (p less than 0.001), but did not correlate with resting lower esophageal sphincter pressure. After treatment lower esophageal sphincter pressure fell by 63% (p less than 0.01). A similar improvement was observed in esophageal emptying at 5 min after both pneumatic dilatation (63%, p less than 0.01) and surgery (70%, p less than 0.05). Percentage change in lower esophageal sphincter pressure and percentage change in esophageal emptying were significantly correlated (r = 0.76, p less than 0.01). There was also a significant correlation between symptom score and percentage change in both esophageal emptying (r = 0.70, p less than 0.05) and LES pressure (r = 0.77, p less than 0.05). Radionuclide measurement of esophageal emptying using a solid meal is a simple, noninvasive, and physiologic test of esophageal function. In achalasia, changes in emptying after treatment generally reflect the patient's clinical status and correlate with changes in lower esophageal sphincter pressure. The results suggest that radionuclide esophageal emptying of a solid meal may be a practical alternative to esophageal manometry in the assessment of treatment and may have an important future role as an objective parameter in comparing new treatment modalities.

Adolescent↗
PubMed1982

Gold- 195m, a new generator-produced short-lived radionuclide for sequential assessment of ventricular performance by first pass radionuclide angiocardiography.

The feasibility of performing rapid sequential first pass radionuclide angiocardiography using a new short-lived radiotracer, gold-195m (195mAu) half-life 30.5 seconds) was evaluated. This radionuclide emits a 262 keV gamma ray and is the daughter of mercury-195 (195mHg) (half-life 41.6 hours). The prototype tabletop 195mHg/195mAu generator produced 20 to 25 mCi of 195mAu in 2 ml of eluate (yield of 40 percent). The breakthrough of 195mHg in the eluate was 0.02 percent of the amount of 195mHg in the generator. The eluate contained 20 microCi of 195mHg per study, resulting in an estimated human radiation dose of 0.007 rad/study to the whole body and 0.34 rad/study to the kidney. Four dogs each had 15 to 20 sequential first pass studies performed with 195mHg at 3 to 10 minute intervals using a computerized multicrystal gamma camera. During the left ventricular phase, 160,000 to 190,000 counts/s were acquired. The end-diastolic left ventricular region of interest contained 3,000 to 6,000 counts (background- and decay-corrected). Multiple reproducible values for left ventricular ejection fraction were obtained during stable conditions. The mean (+/- standard deviation) interstudy variability was 4 +/- 2 percent. During infusion of isoproterenol, rapid increase of left ventricular ejection fraction was demonstrated. Excellent agreement was observed between studies performed with technetium-99m diethylenetriaminepentaacetic acid (99mTc-DTPA) and 195mAu. The mean interstudy difference was 4 +/- 3 percent. Thus, sufficiently high yield and dose are obtained from the 195mHg/195mAu generator for reliable high count rate first pass determination of left ventricular ejection fraction. This new short-lived radiotracer makes possible rapid sequential assessments of ventricular function at greatly reduced patient exposure to radiation.

Angiocardiography↗
PubMed1981

Abdominal and hepatic uptake of 99mTc-pyrophosphate in neonatal necrotizing enterocolitis.

Abdominal 99mTc-pyrophosphate (99mTc-PYP) scans were obtained in 15 neonates: 12 with neonatal necrotizing enterocolitis (NEC), two with osteomyelitis, and one with myocarditis. Ten of the babies with NEC had at least one positive scan; of these 10 studies, seven (Group A) showed both diffuse abdominal uptake and localized hepatic activity, two (Group B) showed abdominal uptake and questionable hepatic uptake, and one (Group C) demonstrated diffuse abdominal uptake only. The other two babies with NEC had normal scans (Group D). Pneumatosis intestinalis was unquestionably present in two patients from Group A and one from Group B. Upon resolution of the clinical findings, all NEC patients had normal scans. A patient with myocarditis had hepatic uptake of 99mTC-PYP while the abdominal scan in the two infants with osteomyelitis was normal. These preliminary observations suggest that further study of a relationship between abdominal scan findings and the course of NEC is warranted.

Abdomen↗
PubMed1981

Alterations in cerebral blood flow in preterm infants with intraventricular hemorrhage.

Xenon-133 inhalation hemispheric cerebral blood flow (HCBF) determinations at one to two days and four to six days postnatally and at 37 weeks postconceptual age have been correlated with computed tomography (CT) scan and autopsy findings in 15 preterm infants weighing less than 1,250 gm at birth. Ten of these infants had germinal matrix hemorrhages (GMH) or intraventricular hemorrhages (IVH). Although HCBF obtained at one to two days showed no mean difference between the GMH/IVH group and the nonhemorrhage infants, hemispheric flow ratios showed significant discrepancies in the GMH/IVH group. In addition, in four of five patients in whom the hemorrhage appeared asymmetric on CT scan, the side of higher flow correlated with the hemorrhage. At four to six days HCBF showed a lower mean value in the GMH/IVH patients than in the nonhemorrhage patients and differences in the interhemispheric ratios in the GMH/IVH group persisted. There were no differences in the mean HCBF values or hemispheric ratios between the two groups of infants at 37 weeks postconceptual age.

Cerebral Hemorrhage↗
PubMed1978

Ventilation patterns mimicking COPD in patients with diaphragmatic pacing for Ondine's curse.

Ventilation was studied with 133Xe in 18 patients with central hypoventilation (Ondine's Curse) in whom diaphragmatic pacers were implanted. Three distinct patterns emerged: Type I, improvement in ventilation on the paced side (11 of 18 patients); Type II, improvement on both the paced and unpaced side (4 of 18); and Type III, no improvement (3 of 18). With the pacer off, many of these patients have patterns that mimic chronic obstructive pulmonary disease and that revert to normal with pacing. This retention, clearly reversible, cannot reflect permanent airways or airspace disease.

Adult↗
PubMed1976

The usefulness of the posterior oblique views in perfusion lung imaging.

A total of 116 perfusion lung images, with and without posterior oblique views, were compared by four trained observers. There was a significant increase in the number of perfusion defects detected when the posterior oblique views were included. Pairs of projections of 89 lung images were read by the four observers. The percentage of correct readings for the posterior oblique views was 78% compared with 63% and 56% for the lateral views and AP views, respectively. Inclusion of the posterior oblique views as a routine part of the examination is recommended.

Humans↗