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Biomedical subjects

R B Scott

Publications and source records attributed to R B Scott.

At least 109 records · Page 6Linked to original sources
PubMed1986

Iron status and liver function in healthy adults: a multiracial pilot study.

We tested 157 apparently healthy, urban adults (78 black, 40 nonblack, 39 race not designated), and found that 7.7% of the entire group had high plasma ferritin levels (6.4%) or transferrin saturation levels (1.3%). Overall, men had significantly higher mean plasma ferritin, serum glutamic pyruvic transaminase, and total serum bilirubin values than women. In this study 17.6% of black men had high plasma ferritin levels and another 11.8% had high transferrin saturation levels. Their mean serum iron and transferrin saturation levels were significantly higher than those of nonblack men. Black men had significantly higher mean serum iron, transferrin saturation, plasma ferritin, serum glutamic pyruvic transaminase, and total serum bilirubin levels than black women. The same tests were not significantly different when black and nonblack women were compared. Likely causes of the laboratory abnormalities are occult inflammation and occult liver disease, but a primary disorder of iron metabolism is also possible.

Adult↗
PubMed1986

Pitted red cell counts in sickle cell disease. Relationship to age, hemoglobin genotype, and splenic size.

Splenic reticuloendothelial function, as determined by pitted red cell counts in 114 pediatric patients with sickle cell disease, was evaluated. Patients with homozygous sickle cell disease (HbSS) had a mean pit count of 11.8 +/- 7.0% and the count increased with age. Sickle cell hemoglobin C disease (HbSC) patients had a mean pit count of 4.9 +/- 9.1%, the count being unaffected by age. One patient with HbS-beta thalassemia had a count of 12%, while eight patients with HbS-beta + thalassemia had a mean count of 0.4 +/- 0.3%. There was one patient each with HbSS-alpha thalassemia, HbS-O Arab, and HbS-Lepore, and the pit counts were 4.9, 31.4, and 0.4%, respectively. In both HbSS and HbSC patients, the pit count was significantly lower in patients who had palpable spleens. The pit count may be used as a predictor of disease severity in the sickle cell disorders.

Adolescent↗
PubMed1986

Effect of duodenal bile acid delivery on fasting intestinal motor activity.

Fasting duodenal bile acid delivery is pulsatile and is cyclically coordinated with the duodenal migrating myoelectric complex (MMC). To determine whether duodenal bile acid delivery influences the duodenal cycle period (CP) of the MMC or the intensity of duodenal motor activity, three dogs were prepared with a duodenal cannula, permitting cannulation of the common bile duct, duodenal infusion, and manometry. CP was measured with the enterohepatic circulation intact and after the common bile duct was cannulated to divert endogenous bile from the duodenum during continuous duodenal infusion (1.6 ml/min) of 0, 2.5, 12.5, or 25 mM sodium taurocholic acid in 154 mM NaCl. During a second protocol with the enterohepatic circulation intact, a control and subsequent CP were measure, and a pulse (1 ml/min for 10 min) of pooled dog bile (112 mM total bile acids) or 0, 20, 80, or 140 mM sodium taurocholic acid in 154 mM NaCl was infused into the duodenum at 40% of the second CP (as estimated from control CP). A motility index was calculated for an interval commencing at 40% of the control CP and at the start of pulse infusion in the succeeding CP. There was no significant difference in CP with the enterohepatic circulation intact compared with that during continuous duodenal infusion of sodium taurocholic acid. There was no significant change in CP or motility index after premature pulse infusion of sodium taurocholic acid or pooled dog bile. Variation in duodenal bile acid delivery did not modulate intensity of duodenal motor activity or cycling of the MMC.

Animals↗
PubMed1985

Advances in the treatment of sickle cell disease in children.

Support from the national sickle cell disease program in the United States is resulting in significant advances in health care. Ten regional comprehensive sickle cell centers provide a variety of management strategies. An example is the inauguration of neonatal diagnosis for sickle hemoglobinopathies, with parental education and the utilization of special follow-up clinics for affected infants. The administration of prophylactic antibiotics and improved vaccines for control of life-threatening infection is enhancing survival in infants and children. A number of antisickling agents are under preliminary clinical investigation in adult patients. Bone marrow transplantation represents another potential method for management of selected types of sickle cell disease. The results of a national cooperative study on the clinical course of the disease, which was inaugurated in 1978, is providing new information that will be helpful to clinicians and health planners. The federally funded sickle cell centers have effectively utilized interdisciplinary personnel to provide comprehensive medical care, psychosocial support, and patient education. These centers serve as models or bridges whereby the fruits of research activity can be more readily applied to the care of patients. This comprehensive approach, no doubt, can contribute to improvement in the survival of and quality of life for patients. There is, however, a need to continue national support for research efforts to attain a definitive cure for this serious, painful, and disabling illness, which affects about 50,000 people in the United States and many more in other countries. Currently, many families of affected patients are unable to cope personally with socioeconomic problems imposed by the long-term nature of this illness, insufficient income, inadequate insurance coverage, and escalating costs of health care. Clearly, there is a need for additional state and/or federal programs to provide supplements for the medical expenses incurred by persons with long-term handicapping diseases of genetic origin.

Anemia, Sickle Cell↗
PubMed1985

Proliferation-associated changes in in vitro mRNA translation in the HL60 cell line.

In order to characterize patterns of gene expression during the proliferation cycle of HL60 cells, we have analysed changes in the population of mRNA available for translation in vitro. HL60 cells were separated into cell cycle phases by centrifugal elutriation, monitoring the separation with flow cytometry. RNA was extracted from cell fractions highly enriched in G1, S or G2+M phases and translated in vitro. Translation products were analysed by two-dimensional electrophoresis followed by autoradiography. Autoradiograms were analysed by a computer-assisted method utilizing a drum-scanning microdensitometer. Spots were identified by their relative positions on the films and their relative intensity was estimated. Of the 159 peptides studied for cell cycle-associated changes in synthesis, nine showed phase-associated changes. The most significant changes were the accumulation of four peptides that showed maximal synthesis only in G2+M phases. An additional four peptides were synthesized maximally in both S and G2+M phases. One peptide showed maximal synthesis in S phase. These changes in gene expression suggest that these relatively abundant transcripts are regulated primarily at a quantitative level during proliferation and may be related to the doubling of structural proteins prior to mitosis.

Cell Line↗
PubMed1985

Gastroesophageal reflux in patients with cystic fibrosis.

Children with cystic fibrosis (CF) and their asymptomatic siblings were surveyed to determine the incidence of symptomatic gastroesophageal reflux. A subgroup of patients with CF with poor nutritional status were studied with esophageal manometry, 24-hour esophageal pH recording, and pulmonary function testing before and after initiation of supplemental continuous nighttime nasogastric feeds. Of 68 patients with CF greater than or equal to 5 years of age, 20.6% experienced regurgitation and 26.5% had heartburn. In the control group of 23 asymptomatic siblings greater than or equal to 5 years of age, none experienced regurgitation and 5.6% had heartburn. Among the patients there was no significant association between symptoms of gastroesophageal reflux and bronchodilator therapy. Eight patients had normal lower esophageal sphincter pressure of 24.8 +/- 8.8 mm Hg and thoracoabdominal pressure gradient of 11.4 +/- 4.6 mm Hg; peristalsis and upper esophageal sphincter pressure were normal. There was a significant increase in reflux episodes, episodes greater than 5 minutes, duration of the longest episode, and percent time esophageal pH was less than 4 in patients, compared with published control data, for the entire 24-hour period and during sleep. During sleep, continuous nasogastric feeding significantly increased episodes of reflux, but did not result in an increase in percent time esophageal pH was less than 4, and was not associated with evidence of aspiration or deterioration in pulmonary function. Our findings indicate that symptoms of gastroesophageal reflux, heartburn, and regurgitation are more frequent in patients with CF than in asymptomatic siblings and that gastroesophageal reflux is significantly more common in patients with CF than in controls. Nighttime nasogastric feedings can safely be used as a means of nutritional rehabilitation in patients with CF.

Adolescent↗
PubMed1985

Electronically determined red blood cell values in a large number of healthy black adults. Subpopulations with low hemoglobin and red blood cell indices.

Using an electronic blood cell counter, the authors determined the hemoglobin, hematocrit, red cell count, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration of 3,668 healthy black adults (1,515 men and 2,153 women) screened 1977-1980 at a mobile health unit operating in Washington, DC, and the surrounding counties in Virginia and Maryland. As expected, males had higher hemoglobin levels than females at all ages. However, these differences diminished with age, both because of a slight increase in hemoglobin values among older females and a decrease in hemoglobin values among older males. Cumulative frequencies of hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin were plotted using probability scales. Among black males, subpopulations with low hemoglobin values and low red cell indices were identified. Because iron deficiency is uncommon in adult males, these findings are probably attributable to alpha- and beta-thalassemia traits. Among black females, individuals with microcytic and hypochromic red cells were detectable at all ages, but a clearly identifiable group with low hemoglobin did not become apparent until after 60 years of age. The authors speculate that mild iron deficiency may have selectively affected the hemoglobin level of non-thalassemic females.

Adult↗
PubMed1985

Painful crises and menstruation in sickle cell disease.

Fifty-two women with sickle cell disease, having genotypes of hemoglobin SS, SC, and S-thalassemia, participated in a questionnaire study pertaining to the relationship of their menses and the occurrence of painful crises. The data indicated that those patients who had sickle cell crises were significantly older and had been menstruating longer, with heavier periods. The results point to the onset of menstruation as a possible precipitant of painful crises in some women with sickle cell disease.

Adolescent↗
PubMed1985

Laxative abuse and secretory diarrhoea.

Three children with chronic diarrhoea secondary to laxative abuse are reported. Growth disturbance, a previously unrecognised feature of this form of abuse, is recorded.

Adolescent↗
PubMed1985

Regulation of fasting canine duodenal bile acid delivery by sphincter of Oddi and gallbladder.

Bile delivery into the duodenum during fasting is rhythmic and coordinated with the migrating myoelectric complex (MMC). To determine the role of the sphincter of Oddi (SO) and gallbladder (GB) in regulating duodenal bile acid delivery, three dogs were surgically prepared with a duodenal cannula and eight bipolar electrodes implanted from the duodenum to the terminal ileum. Fasting intestinal myoelectric activity was recorded during continuous intravenous infusion of [14C]taurocholic acid (TCA). Duodenal delivery of TCA was quantitated under four conditions: indirectly with the SO intact monitoring output with duodenal marker perfusion and directly with the SO cannulated and draining at three levels to vary outflow resistance (5 cm above, level with, or 20 cm below the SO). GB filling or emptying represented the algebraic difference between hepatic secretion (equal to the intravenous infusion rate) and rate of TCA delivery into the duodenum. With the sphincter intact the rate of bile acid delivery averaged one-half the intravenous infusion rate at 0-40% of the MMC cycle period, rose to exceed the intravenous infusion rate at 60-70% of the cycle period, and then fell to lower levels before the next MMC began. The pattern of delivery was identical with the SO cannulated, but the rate and percent infused TCA delivered into the duodenum depended significantly (P less than 0.01) on outflow resistance. They were least with the reservoir elevated 5 cm, intermediate when level, and greatest when 20 cm lower. Thus, duodenal bile acid delivery and GB filling or emptying during fasting were cyclically coordinated with the MMC. Peak rates of duodenal bile acid delivery and active GB emptying occur at 70% of the duodenal cycle period. Elimination of the SO does not eliminate the pulsatile pattern of fasting duodenal bile acid delivery, but outflow resistance determines the quantities delivered into the duodenum or stored in the GB. Thus, during the interdigestive period the net effect of SO function does not differ from a constant output resistance favoring the partition of hepatic biliary secretion into the GB and away from the duodenum, while the pulsatile pattern of duodenal bile acid delivery associated with the MMC results from cyclic active contraction of the GB.

Ampulla of Vater↗
PubMed1985

Characteristics of menstruation in sickle cell disease.

The results of this preliminary study indicate that patients with sickle cell disease have shorter menstrual cycles than normal control subjects. Their periods last longer and are heavier, and they have a greater incidence of dysmenorrhea. This study provides some insight into the menstrual characteristics of these patients and, we hope, can contribute to the counseling and management of patients with this disease.

Adolescent↗
PubMed1985

Correlation of serum ferritin with other tests of iron status in sickle cell disease.

The iron status of 42 patients with homozygous SS disease, none of whom was on chronic transfusion therapy, was investigated using tests for serum ferritin, serum iron, serum transferrin, transferrin saturation, and free erythrocyte protoporphyrin. Correlation coefficients were computed between ferritins and the other test results. The mean ferritin level of the group as a whole showed significant inverse linear correlation with the mean transferrin and free erythrocyte protoporphyrin values. The mean ferritin of the subgroup with normal ferritin levels correlated significantly only with the mean free erythrocyte protoporphyrin value. The mean ferritin of the subgroup with high ferritin levels correlated significantly only with the mean transferrin value. In these patients who had received only sporadic blood transfusions, there was poor correlation of ferritin levels with age and number of transfusions.

Adolescent↗
PubMed1984

Sulfasalazine-induced colitis complicating idiopathic ulcerative colitis.

A diagnosis of idiopathic ulcerative colitis was made in a previously healthy 9-year-old boy. Symptoms persisted despite therapy with sulfasalazine, 50 mg/kg daily, but they eventually responded to treatment with parenteral nutrition and prednisone, 40 mg daily. Metronidazole was also given to eradicate persistent Dientamoeba fragilis from the stools. The symptoms resolved over 3 weeks, and the daily dose of prednisone was tapered. On two subsequent occasions a challenge with sulfasalazine caused an immediate recurrence of loose, blood-streaked stools and of nonspecific histologic features of ulcerative colitis, which resolved when the sulfasalazine was discontinued.

Child↗
PubMed1984

Fasting canine biliary secretion and the sphincter of Oddi.

This study correlates duodenal bile acid delivery with motility of the sphincter of Oddi during the fasting state. Dogs were prepared with a functional cholecystectomy, a duodenal cannula for direct vision cannulation of the common bile duct, and 12 bipolar electrodes serosally implanted from stomach to terminal ileum. In one set of experiments, the bile acid pool was depleted, and during a continuous i.v. infusion of sodium taurocholate (20 mumol/min), duodenal bile acid delivery was assessed over 6 h by a marker perfusion technique. In other experiments, a double-lumen continuously perfused manometry catheter was placed to record motility in the bile duct and sphincter of Oddi for a period of 6 h. Station pull-throughs of the sphincter of Oddi were performed in each phase of the migrating motor complex. Bile acid secretion rates fluctuated about the i.v. infusion rate during duodenal phase I and II, peaked in late phase II, and then fell to barely detectable levels during duodenal phase III. There was no peristaltic contractile activity in the common bile duct in any phase of the migrating motor complex. The sphincter of Oddi maintained a baseline pressure above common bile duct pressure. It was highest during phase III. Phasic contractions of the sphincter of Oddi were intermittent during phase I, increasingly frequent during phase II, and continuous during duodenal phase III of the migrating motor complex. Contractions were frequently peristaltic. We concluded that the occurrence and amplitude of phasic peristaltic contractions of the sphincter of Oddi are cyclically coordinated with the fasting intestinal motor pattern (migrating motor complex), and with cyclical variations in the delivery of bile acids into the duodenum. Both resting pressure and phasic contractions of the sphincter appear to play a role in coordinating the cyclic delivery of bile acids into the duodenum with the migrating motor complex. Intense phasic motor activity appears to impede bile flow, and less intense activity allows or facilitates flow.

Action Potentials↗