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Biomedical subjects

P B Meier

Publications and source records attributed to P B Meier.

12 recordsLinked to original sources
PubMed1998

Measurement of soluble transferrin receptor in serum of healthy adults.

The concentration of soluble transferrin receptor (sTfR) in serum is reported to be useful in the diagnosis of iron deficiency, especially for patients with concurrent chronic disease, where routine tests of iron status are compromised by the inflammatory condition. A new diagnostic assay for sTfR is calibrated against natural plasma sTfR, thus minimizing calibration discrepancies that result from differences between the analyte and the cellular transferrin receptor used in other assays. Use of the new assay to measure sTfR concentrations in 225 healthy, hematologically normal adults provided a reference interval against which pathological samples could be compared. There was no difference in the reference intervals for men and women and no correlation of [sTfR] with the age of the subject. Black subjects had significantly higher concentrations than nonblacks, and people living at high altitude had higher concentrations than those living closer to sea level. These differences were additive.

Age Factors↗
PubMed1993

Results of a multicenter trial using a mechanical lithotripter for the treatment of large bile duct stones.

A prospective, uncontrolled trial of the use of a prototype mechanical lithotripter was performed in 116 patients at nine centers. Standard endoscopic approaches had failed to remove all stones, primarily because of large size (80% of patients). For 92% of patients, common bile duct stones were successfully captured and fragmented following the use of this lithotripter. The frequency of pancreatitis and hemorrhage was no greater than with standard endoscopic retrograde sphincterotomy, and complications unique to lithotripter use were not noted. For endoscopists skilled in therapeutic duodenoscopy, this modality should be considered in management of common bile duct stones refractory to standard techniques.

Equipment Design↗
PubMed1989

A US multicenter study of enprostil 35 micrograms twice daily for treatment of prepyloric, pyloric channel, and duodenal bulb ulcers. Enprostil Study Group.

One hundred twenty-seven patients with endoscopically diagnosed active duodenal, pyloric, or prepyloric ulcers participated in this multicenter, double-blind, randomized, controlled trial comparing placebo with enprostil 35 micrograms twice daily for up to four weeks. Cumulative endoscopic healing for the enprostil and placebo treatment groups, respectively, was 25% (15 of 59) and 12% (7 of 60) at two weeks (P = 0.060) and 59% (34 of 58) and 33% (19 of 57) at four weeks (P = 0.005). Excluding prepyloric ulcers, cumulative healing for the enprostil and placebo groups, respectively, was 22% (9 of 41) and 7% (3 of 44) at two weeks (P = 0.104) and 56% (23 of 41) and 24% (10 of 42) at four weeks (P = 0.002). A greater percentage of prepyloric ulcers healed on enprostil than placebo, but the difference was not significant. Mean antacid use in both groups was identical, averaging only two or less tablets per day in each group throughout the study. Daytime pain was relieved more quickly in the enprostil group, while median time to relief of nighttime pain was essentially identical in both groups. The most common side effect in the enprostil treatment group, diarrhea, was mostly mild to moderate in intensity and was generally self-limiting, requiring no specific therapy; no patient withdrew because of this complaint. Other symptoms and laboratory profiles were similar in the two groups. These results indicate that enprostil 35 micrograms taken twice daily for four weeks is effective and safe for the treatment of prepyloric, pyloric channel, and duodenal ulcers.

Adult↗
PubMed1988

Efficacy of chenodeoxycholic acid and ursodeoxycholic acid for lowering cholesterol saturation index of gallbladder in patients with a sphincterotomy.

After endoscopic retrograde sphincterotomy, patients with an intact gallbladder are at risk for developing symptoms or complications of gallbladder stones. Medical dissolution of such stones would be desirable, especially in elderly patients with an increased surgical risk. However, sphincterotomy alters emptying dynamics of the gallbladder and markedly reduces bile salt pool size, effects that may alter response to chenodeoxycholic acid or ursodeoxycholic acid treatment. Studying two groups of 5 patients with an intact gallbladder after endoscopic retrograde sphincterotomy, we found that 15 mg/kg.day of chenodeoxycholic acid increased the mean (+/- SEM) biliary percentage of chenodeoxycholic acid from 35.5% +/- 4.0% to 88.8% +/- 1.9% (p less than 0.01) and decreased the mean saturation index of gallbladder bile from 1.02 +/- 0.22 to 0.55 +/- 0.08 (p less than 0.05). Ursodeoxycholic acid (10 mg/kg.day) increased the mean biliary percentage of ursodeoxycholic acid from 5.6% +/- 1.5% to 44.7% +/- 5.8% (p less than 0.01) and decreased the mean saturation index of gallbladder bile from 1.04 +/- 0.25 to 0.57 +/- 0.03 (p less than 0.05). A long-term trial of bile acid treatment in sphincterotomy patients with stones in an intact gallbladder is needed.

Aged↗
PubMed1987

Pseudomonas infection of the biliary system resulting from use of a contaminated endoscope.

Pseudomonas aeruginosa was present in bile cultures from 10 patients who had undergone previous endoscopic retrograde cholangiopancreatography in 1984. After environmental cultures and review of instrument disinfection, we traced the infections to a single endoscope contaminated with P. aeruginosa, serotype 10. Although the instrument had been cleaned repeatedly with an automatic endoscope cleaning machine, P. aeruginosa survived on residual moisture left in the channels of the endoscope. Contamination ended only after we began to manually suction alcohol through the endoscope before air drying. In 5 of 10 patients, P. aeruginosa caused clinical infections including gangrenous cholecystitis, abscesses, and death. We could identify no factor that distinguished symptomatic from asymptomatic patients. In asymptomatic patients, P. aeruginosa was recovered from gallbladder bile up to 2 mo after endoscopic retrograde cholangiopancreatography. As this P. aeruginosa epidemic was discovered retrospectively because we monitor bile cultures, we advocate this practice as part of endoscopic retrograde cholangiopancreatography procedures.

Bile↗
PubMed1987

Temperature dependence of macroamylase binding.

The presence of macroamylasemia can be suspected when a patient has low renal clearance of amylase relative to creatinine (Cam/Ccr). However, the Cam/Ccr is seldom reduced to the extent expected given the fraction of amylase that appears to be bound in the macroamylase complex by gel filtration studies at 3 degrees C. Therefore, we tested the possibility that the binding of amylase in macroamylase complexes was temperature dependent and that binding at physiological temperatures might be less than at 3 degrees C. Gel filtration of five macroamylase-containing sera was carried out at temperatures of 3 degrees, 25 degrees, 37 degrees, 43 degrees, and 49 degrees C. Binding of amylase in the complex decreased as the temperature increased with virtually all amylase bound at 3 degrees C and virtually no amylase bound at 49 degrees C. The fraction of the amylase that bound at 37 degrees C was approximately what would have been predicted from the Cam/Ccr of each of the five subjects. We conclude that amylase binding in macroamylase complexes is extremely temperature sensitive and appreciable changes in binding may occur over the physiological temperature range of 37-41 degrees C.

Amylases↗
PubMed1986

Urine protein excretion in acute pancreatitis.

The mechanism of the increased renal clearance of amylase and the amylase to creatinine clearance ratio (CAM/CCR) in acute pancreatitis remains controversial with both renal tubular dysfunction and altered glomerular permeability being invoked as explanations. To differentiate between these mechanisms, we investigated the quantity and character of protein excretion in 10 patients with pancreatitis. For a short period of time, seven of 10 patients had mild proteinuria with a mean protein excretion rate of 230 +/- 154 mg/24 hr. Proteinuria decreased in 9/9 survivors to 17 +/- 18 mg/24 hr. Albumin excretion rate initially was minimally increased in 10/10 patients with a mean of 61 +/- 40 mg/24 hr, decreasing during recovery in 8/9 survivors to 10.9 +/- 10.4 mg/24 hr (P less than 0.01). Electrophoresis of urine obtained during the acute phase consistently showed a low molecular weight proteinuria pattern that cleared with recovery. Twenty-one of 22 urinary samples with an elevated CAM/CCR had a low molecular weight protein pattern. All the above findings can be explained by alterations in renal tubular reabsorption of proteins without changes in glomerular permeability. In 2/4 patients a low molecular weight protein was present in urine specimens from the acute phase that was not present in highly concentrated urine specimens from the recovery period. This raises the possibility that an abnormal low molecular weight protein enters the serum in acute pancreatitis, which, after glomerular filtration, produces the renal tubular malfunction found in acute pancreatitis.

Albuminuria↗