Human proinsulin standards

Two new batches of pancreatic human proinsulin have been compared with biosynthetic human proinsulin. Standards of these three proinsulin preparations were made on the basis of quantitative amino-acid analyses and compared in two proinsulin radioimmunoassays with a proinsulin standard prepared 14 years ago. The curves of the new standards were superimposable. However, they differed considerably from the curve of the old standard which proved to be only one-third of the strength of the new standards, thereby leading to a threefold over-estimation of proinsulin concentrations when the old standard is used. We conclude that the new standards should replace previously used standards.

Bone mineral content in patients on prolonged maintenance hemodialysis: a three year follow-up study

Bone mineral content (BMC) was measured annually over a three year period in 31 consecutive patients on maintenance hemodialysis (HD). No patient had received treatment with vitamin D derivatives, anticonvulsants or corticosteroids, nephrectomy or a renal transplant. Initial median BMC value in per cent of sex and age matched normal mean was significantly decreased to 91.0% (P less than 0.01), indicating bone mineral loss in chronic renal failure prior to HD. During HD a highly significant fall in mean BMC (in per cent of initial value) continued to 95.1%, 92,7% and 90.8% after 1, 2 and 3 years, respectively, with no influence of age, sex or initial BMC value. The interindividual variation in BMC changes, however, was considerable: the BMC loss over 3 years exceeded 10% in 13 (42%) patients ("rapid losers") while 12 (39%) patients had a BMC loss below 5%, or no loss at all. The "rapid loser" group had significantly higher serum levels of parathyroid hormone and alkaline phosphatases and, moreover, developed a lower serum phosphate and calciumXphosphorus product than the other group of patients ("slow losers"). The mean BMC loss over 3 years of HD was pronounced and significant (P less than 0.02) in patients with chronic pyelonephritis (9.8%) and polycystic kidney disease (14.2%), but much smaller, and not significant, in patients with chronic glomerulonephritis (4.8%). It is concluded that a selection of patients with a high degree of bone mineral loss during HD is not possible by means of sex, age, initial BMC, biochemical parameters, or diagnosis (2 patients with chronic glomerulonephritis appeared to be "rapid losers"). For that purpose a high-precision BMC method is mandatory.

Aqueous immune complexes in immunogenic uveitis

A primary immunogenic uveitis was produced in rabbits by the intravitreal injection of bovine plasma albumin or ovalbumin. A secondary or recurrent uveitis was induced by intravenous injection of the specific soluble antigen several months after the cessation of primary inflammation. Aqueous antigen-antibody complexes were studied at times of maximal clinical response in both primary and recurrent forms during resolution of primary immunogenic uveitis, and in a nonspecific protein extravasation induced by aqueous paracentesis. Immune complexes could be demonstrated only during times of clinically evident inflammation in immunogenic uveitis. The results indicate the importance of antigen-antibody complex formation in the pathogenesis of this form of experimental ocular inflammatory disease.

Bioavailability of zinc from a diet based on isolated soy protein: application in young men of the stable isotope tracer, 70Zn

With the aid of the stable isotope, 70Zn, as a tracer and neutron activation analysis, a combination of extrinsic labeling of meals and fecal monitoring of isotope excretion was used as a safe and noninvasive approach for assessing the effects of the vegetable (soy) and animal (milk, beef) proteins on the absorption of zinc in healthy, adult human volunteers. A known amount of 70Zn was added as ZnCl2, to six consecutive meals over a 2-day period during which either one of three isonitrogenous liquid formulas (skim milk; soy isolate; or a 50:50 mixture) or one of two bologna sausages (soy isolate of beef) were given. The mean absorption of 70Zn from milk, soy and soy/milk was 41 +/- 4, 34 +/- 4, and 41 +/- 7% (mean +/- SEM), respectively, the presence of soy protein having no effect on absorption of the extrinsic label. For beef bologna and soy bologna, fractional absorption of the 70Zn tracer was 41 +/- 4 and 30 +/- 3%, respectively. Beef might favor absorption of extrinsic zinc. The kinetics of isotope excretion, pooling procedures, for stool samples and the utility of fecal markers were also evaluated.

The diagnostic value of fasting serum total bile acid concentration in patients with suspected liver disease. A prospective, consecutive study

To assess the diagnostic value of fasting serum total bile acids (STBA) in liver disease, STBA together with serum bilirubin (BIL), serum alkaline phosphatase (AP), and serum aspartate aminotransferase (ASAT) were measured in 66 consecutive patients who had a liver biopsy. Twenty-four of the patients who had normal liver histology all had normal STBA values (less than 8 mumol/l). In the remaining 42 patients with abnormal liver histology STBA values were elevated in 21, corresponding to a sensitivity of 0.50. The same figures for BIL, AP, and ASAT were 0.52, 0.76, and 0.79, respectively. The predictive values of elevated (PVpos) and normal (PVneg) STBA for disclosing or excluding liver disease, respectively, were not better than the figures for BIL, AP, and ASAT. None of the tests were suited for distinguishing among various liver diseases. It is concluded that STBA had no diagnostic advantage as compared with the commonly used liver function tests BIL, AP, and ASAT.

Interagency collaboration: driving and restraining forces

An information base on interagency collaboration which can be used to direct the development of training strategies for persons involved in the design or operation of interagency endeavors is presented. Interagency collaboration is defined as a process in which two or more agencies integrate their resources to provide services to meet the individual needs of handicapped learners. Many key factors are associated with the success of interagency agreements, the most important being the degree to which people associated with the program can work together. The vehicles used to generate the information base were literature review, a working conference, and five case studies.

An investigation of the efficacy of oral myofunctional therapy as a precursor to articulation therapy for pre-first grade children

This study investigated the assumption that oral myofunctional services might facilitate remediation of articulation disorders. Subjects were ten 6-year-old elementary school children who exhibited both tongue-thrust behaviors and articulation errors. All subjects had equal service time for a 14-week period, half receiving articulation services only and the other half receiving oral myofunctional services prior to and in conjunction with articulation services. Results showed that children in both programs made essentially equal progress in correcting placement of tongue-tip sounds, remediating /s/ and /z/ misarticulation, and remediating general articulation errors. Only children who received oral myofunctional services remediated tongue-thrust behaviors.

Immune complexes in Sjögren's syndrome

Sera from 48 patients with Sjögren's syndrome were examined for immune complexes by the Raji cell assay. There was no correlation between levels of immune complexes and the degree of lymphocytic infiltration of the labial salivary glands. Serum complement levels were normal. Five patients were serially followed during the development of pseudolymphoma or malignant lymphoma. Immune complex levels in 4 of the 5 patients were generally unchanged throughout the illness and did not parallel disease activity, rheumatoid factor, or SS-A and SS-B concentrations. Possible roles for immune complexes in Sjögren's syndrome are discussed.

Immune complexes and carcinoembryonic antigen levels in metastatic choroidal tumors

We studied 11 patients with metastatic choroidal tumors and one patient with a metastatic choroidal melanoma by using the Raji cell radioimmunoassay to detect immune complexes, and the carcinoembryonic assay. Ten (91%) patients with choroidal metastases had an increase of either immune complex levels or carcinoembryonic antigen results.

Characterization of retinoblastoma immune complexes

Immune complexes from retinoblastoma sera were characterized with molecular sieve chromatography, affinity chromatography, and polyacrylamide gel electrophoresis (PAGE). Retinoblastoma patients' sera had two well-defined peaks of immune complex activity after molecular sieve chromatography. These protein fractions had a molecular weight of approximately 1.6 x 10(5) and 2.0 x 10(6) daltons. Affinity chromatography with Sepharose 4B-protein A and analytical PAGE demonstrated that IgG was the predominant immunoglobulin in these immune compelxes. Immune complexes also had affinity for Sepharose-concanavalin A, indicating the glycoprotein nature of the antigen component.

Structure-function studies on red pigment-concentrating hormone, II. The significance of the C-terminal tryptophan amide

The significance of the C-terminal tryptophan residue of the red pigment-concentrating hormone (RPCH: Glu-Leu-Asn-Phe-Ser-Pro-Gly-Trp-NH2) regulating the blanching of the crustacean chromatophores has been investigated. RPCH and a number of analogues that differ only in the C-terminal part of the hormone, have been synthesized and assayed for biological activity on the shrimp Leander adspersus. It has been shown that the indole skeleton of tryptophan is an absolute requirement for the biological activity of the hormone. To provide maximum response the tryptophan must be blocked as the amide. The activity of synthetic [Tyr4]RPCH and adipokinetic hormone (AKH) purified from Schistocerca gregaria has been compared with the activity of synthetic RPCH.

Immune complexes in uveitis

We determined the incidence of immune complex increases, the nature of immune complexes, and the correlation between the immune complex level and clinical uveitis status in patients with chronic iridocyclitis and chronic diffuse uveitis. Ten of 16 patients with chronic iridocyclitis had increased levels of immune complexes, and this correlated with disease activity. Immune complexes were detected in ten of 12 patients with chronic diffuse uveitis. These complexes have a molecular weight of approximately 2 X 10(6) daltons. The antibody component of immune complex is IgG; however; the antigenic component of the immune complexes is unclear.

N-alkylation of amino acid residues by chloromethyl groups. A potential side reaction in the solid phase peptide synthesis

A serious side reaction in the peptide synthesis on the Merrifield resin was observed during attempts to synthesize the TMV fragment, Asn-Pro-Thr-Thr-Ala (101--105). The side reaction is consistent with N-alkylation of the amino groups by the residual chloromethyl groups on the resin, which lowers the total yield and complicates evaluation of monitoring data during the synthesis. It is shown that several amino acids can be N-alkylated in different positions in the peptide chain and in different solvents. The extent of N-alkylation is in some cases 50%.

Immune complexes in retinoblastoma

Thirteen patients with retinoblastoma were tested for circulating immune complexes using the Raji cell radioimmunoassay. Eight of 13 patients had statistically significantly increased levels of immune complexes.

Structure-function studies on red pigment-concentrating hormone; the significance of the terminal residues

The significance of the terminal residues of the red pigment-concentrating hormone (RPCH: Glu-Leu-Asn-Phe-Ser-Pro-Gly-Trp-NH2) for its blanching effect on crustacean chromatophores has been investigated. The chemical synthesis of the following small analogues, starting from the C-terminal amino acid are described: Ac-Trp-NH2, Boc-Gly-Trp-NH2, Ac-Gly-Trp-NH2, Gly-Trp-NH2, Ac-Pro-Gly-Trp-NH2, Glu-Trp-NH2, Glu-Pro-Gly-Trp-NH2, Ac-Pro-Gly and Glu-Pro-Gly-NH2. Assay of the biological activity of the various synthetic compounds in the shrimp Leander adspersus has established that only the C-terminal tryptophan residue is indispensable for the blanching effect of the hormone, although elongation of the chain length improves its potency.

Metastatic basal cell carcinoma: a review of the literature and report of two cases

A total of 95 cases of metastasizing basal cell carcinomas have been recorded in the literature with 20 of these metastatic to bone. Two additional cases of metastasizing basal cell carcinoma with osseous metastases are presented, with a review of the literature.