Role of gallbladder mucin in pathophysiology of gallstones

A critical step in the formation of cholesterol gallstones in nucleation (i.e., the formation of cholesterol monohydrate crystals from supersaturated bile). The rate of nucleation of cholesterol depends upon a critical balance between pronucleating and antinucleating factors in bile. Mucin, a high molecular weight glycoprotein secreted by the gallbladder and biliary duct epithelium, is a pronucleating agent in experimental and human gallstone disease. Gallbladder mucin shares with other epithelial mucins the ability to bind lipids and bile pigment. The hydrophobic binding sites in the polypeptide core of mucin may provide a favorable environment for nucleation of cholesterol monohydrate from supersaturated bile. In nearly all animal models of cholelithiasis, mucin hypersecretion is prominent. The stimulus for gallbladder mucin hypersecretion appears to be a component of lithogenic bile. Prostaglandins regulate mucin release in gallbladder epithelium in vitro and probably in vivo. In the cholesterol-fed prairie dog, blockage of mucin release with aspirin inhibits gallstone formation. These findings suggest that inhibition of mucin release may prevent cholesterol stone formation during high-risk periods or after dissolution therapy with bile salts.

Human gallbladder mucin accelerates nucleation of cholesterol in artificial bile

The gallbladder bile of patients with cholesterol gallstones is characterized by two abnormalities: (a) supersaturation with cholesterol and (b) accelerated nucleation of cholesterol monohydrate crystals. We studied the ability of purified human gallbladder mucin to nucleate artificial bile in vitro. Human gallbladder mucin at concentrations of 2 and 4 mg/ml accelerated the nucleation time of cholesterol crystals in model bile. The mean number of cholesterol crystals in artificial bile incubated for 10 days with 4 mg/ml of human gallbladder mucin was 2327/mm3 (p less than 0.01) vs. control of 51/mm3. The number of crystals found in model bile was dependent on the concentration of human gallbladder mucin (2-16 mg/ml) and the time of incubation (4-14 days). Human gallbladder mucin was associated with an increase in the number of liquid crystals after 4 days of incubation, which then decreased in number as solid cholesterol monohydrate crystals formed. Nucleation by human gallbladder mucin was significantly increased only with cholesterol saturation indices greater than 1.0, and in biles containing 10% but not 3% total lipid by weight. Pooled human gallbladder mucin from gallbladders with and without stones both increased nucleation significantly when compared with controls. Increased nucleation of saturated model bile was also observed with purified monkey cervical and bovine gallbladder mucin, but not with porcine gastric mucin. These observations provide further evidence that human gallbladder mucin may contribute to cholesterol gallstone formation in humans by accelerating nucleation of cholesterol monohydrate crystals from supersaturated gallbladder bile.

Glycosylated haemoglobin and serum insulin antibodies in type I diabetes

Type 1 diabetics receiving once (Group 1, n = 72) and twice (Group 2, n = 48) daily subcutaneous injections of conventional beef insulin were compared, on a cross-sectional basis, in respect of insulin antibody binding by serum and total glycosylated haemoglobin (HbA1). Patients in Group 1 had higher insulin antibody binding (25.2 +/- 15.8% vs 17.0 +/- 13.9%; p less than 0.01) and higher HbA1 levels (12.5 +/- 2.0% vs 11.0 +/- 1.8%; p less than 0.001) than patients in Group 2. An inverse correlation (tau = -0.28, p less than 0.01) was observed between HbA1 and insulin antibody binding in C-peptide non-secretors of Group 1 but not in Group 1 C-peptide secretors, nor in C-peptide secretors and/or non-secretors of Group 2. It is suggested that in Type 1 diabetics who receive a single daily insulin injection and who have no endogenous insulin secretion, insulin antibodies may aid glycaemic control by prolonging insulin action.

Results of a nationwide survey of analyses for creatine kinase and creatine kinase isoenzymes

More than 300 laboratories participated in an interlaboratory survey of creatine kinase (CK, EC 2.7.3.2) determinations in which they analyzed seven lyophilized samples for total CK and CK isoenzymes and furnished information about their methodology. The samples were not necessarily intended to mimic typical patients' specimens but rather to determine the analytical ability of the laboratories to distinguish isoenzyme fraction CK-MB from CK-BB and to detect small but abnormal amounts of CK-BB. For total CK measurement, most laboratories used an NADP+ reduction method monitored at 340 nm (89%), and reported results in units per liter (U/L) (99%) at either 30 degrees C (34%) or 37 degrees C (60%). Despite the variety of analytical conditions, most laboratories (89%) correctly reported results within their normal range for all samples. The 287 laboratories that reported isoenzyme distributions in the samples used either cellulose acetate (37%) or agarose (44%) electrophoresis, ion-exchange chromatography (9%), or immunoinhibition (7%). Results from laboratories that used nonspecific CK-MB immunoinhibition techniques were biased when a significant amount of CK-BB isoenzyme was present.

Results of a nationwide survey of analyses for creatine kinase and creatine kinase isoenzymes

More than 300 laboratories participated in an interlaboratory survey of creatine kinase (CK, EC 2.7.3.2) determinations in which they analyzed seven lyophilized samples for total CK and CK isoenzymes and furnished information about their methodology. The samples were not necessarily intended to mimic typical patients' specimens but rather to determine the analytical ability of the laboratories to distinguish isoenzyme fraction CK-MB from CK-BB and to detect small but abnormal amounts of CK-BB. For total CK measurement, most laboratories used an NADP+ reduction method monitored at 340 nm (89%), and reported results in units per liter (U/L) (99%) at either 30 degrees C (34%) or 37 degrees C (60%). Despite the variety of analytical conditions, most laboratories (89%) correctly reported results within their normal range for all samples. The 287 laboratories that reported isoenzyme distributions in the samples used either cellulose acetate (37%) or agarose (44%) electrophoresis, ion-exchange chromatography (9%), or immunoinhibition (7%). Results from laboratories that used nonspecific CK-MB immunoinhibition techniques were biased when a significant amount of CK-BB isoenzyme was present.

Bovine gallbladder mucin binds bilirubin in vitro

Gallbladder mucin glycoprotein and bilirubin are frequently identified at the center of human cholesterol gallstones, suggesting that mucin-bilirubin complexes might function as nucleating agents for cholesterol gallstones. This study was undertaken to determine if bovine gallbladder mucin was capable of binding bilirubin in vitro. Chromatography of dialyzed bovine gallbladder bile on Sepharose 4B revealed that bile pigment (OD420) eluted in a high-molecular weight fraction also containing mucin, as well as in an included (low-molecular weight) fraction. When bilirubin (98.8% as IX alpha by high-pressure liquid chromatography) and purified bovine gallbladder mucin were ultracentrifuged in a sucrose density gradient, the presence of bilirubin-mucin complexes was observed. Alteration of the polymeric structure of mucin with mercaptoethanol caused loss of its ability to bind bilirubin, suggesting that the native polymeric configuration is required. These results indicate that mucin can bind bilirubin in vitro, and might explain their occurrence in the nucleus of human cholesterol stones.

Cerebrospinal fluid pleocytosis following hemorrhagic cerebral infarction

A polymorphonuclear pleocytosis of the cerebrospinal fluid is an occasional occurrence following hemorrhagic cerebral infarction. Because the peak of this neutrophilic reaction occurs 3 to 4 days after the event it is usually missed and not widely appreciated. We have described an example of this response in an attempt to alert physicians to an important differential diagnostic consideration when faced with a neutrophilic CSF pleocytosis.

Microdiffusion and Fluoride-Specific Electrode Determination of Fluoride in Infant Foods: Collaborative Study

Twelve laboratories analyzed (1 replicate) 12 samples of infant foods – milk, pears, and peas – containing 0.2-5 ppm F. There was one laboratory outlier. Mean coefficients of variation were 7.06% for intralaboratory determination of 3 sets of blind duplicates and 21.6% for interlaboratory determination of 12 samples. Variance analysis for all samples yielded a reproducibility standard deviation of 0.41 ppm; for 3 sets of blind duplicates, repeatability standard deviation was 0.26 ppm and reproducibility standard deviation was 0.32 ppm.

Maximal conservation and minimal usage of blood products in open heart surgery

Open heart surgery has previously been associated with the use of large volumes of blood products. This paper describes methods of blood conservation and a simple method of intraoperative autotransfusion that together have resulted in minimal blood product usage in elective open heart surgery cases. This has reduced our dependence on blood bank supplies for the performance of elective open heart surgery.

A study of thyroid stimulating activity in human serum with the highly sensitive cytochemical bioassay

The cytochemical bioassay is able to detect minute amounts of thyroteopin and thyroid stimulating immunoglobulins. Estimations of serum TSH by the cytochemical bioassay are in good agreement with values obtain by radioimmunoassay. In untreated hyperthyroid patients with Graves' disease the TSH levels are significantly lower than in control subjects. Thyroid stimulating immunoglobulins showed a delayed time corse of action in the bioassy and this provided a voncenient method of distinguishing between the two thyroid stimulators.

Polarized Magnetic Field Fluctuations at the Apollo 15 Site: Possible Regional Influence on Lunar Induction

High-frequency (5 to 40 millihertz) induced lunar magnetic fields, observed at the Apollo 15 site near the southeastern boundary of Mare Imbrium and the southwestern boundary of Mare Serenitatis, show a strong tendency toward linear polarization in a direction radial to the Imbrium basin and circumferential to the Serenitatis basin, a property that could be indicative of a possible regional influence on the induction.

Whole Body Response of the Moon to Electromagnetic Induction by the Solar Wind

A comparison has been made of the interplanetary magnetic field as measured both by Apollo 12 on the lunar surface and by Explorer 35 in orbit around the moon. Two examples are given, one of a step change in the field vector and another of a sinusoidally varying field. A large response measured on the surface is attributed to confinement of the induced field lines between the streaming solar plasma and the high-conductivity interior. A steep bulk electrical conductivity gradient in the lunar crust is implied, with a confining layer roughly 100 kilometers deep.

Obstruction of bowel due to lesion in the myenteric plexus

Two patients are described who were found to have a destructive lesion of the myenteric plexus. In one the upper small intestine was involved and the clinical picture was of recurrent pseudo-obstruction; in the other the lesion was in the distal colon and resulted in intractable constipation. The lesion cannot be demonstrated by conventional histological techniques, being seen only in silver preparations cut parallel to the bowel wall, and may have been overlooked in the past. The aetiology is unknown.