Collagenase digestion demonstrates carboxy-terminal crosslinking in acid-soluble collagen

Among the products of the collagenase cleavage of Type I acid-soluble collagen from calf and rabbit tendons, there can be found fragments with the lengths of half alpha-chains. Because purified collagenase cleaves the alpha-chains three-quarters of the length from the amino-terminus, the presence of half-length chains is evidence for the occurrence of crosslinks between two carboxy-terminal, quarter-length fragments, The collagen preparations were reduced with [3H]borohydride, the collagenase-cleaved fragments were separated by gel electrophoresis, and their 3H-labeled crosslink derivatives were analyzed. The major labeled components in the half-length chains were the reduced aldol condensation product and hydroxylysinonorleucine. These experiments demonstrate that the carboxy-terminal telopeptides in monomer-enriched collagen samples form aldol crosslinks which are probably intramolecular, but some intermolecular aldol and aldimine crosslinks may also be formed.

The treatment of soft-tissue sarcomas of the extremities: prospective randomized evaluations of (1) limb-sparing surgery plus radiation therapy compared with amputation and (2) the role of adjuvant chemotherapy

Between May 1975 and April 1981, 43 adult patients with high-grade soft tissue sarcomas of the extremities were prospectively randomized to receive either amputation at or above the joint proximal to the tumor, including all involved muscle groups, or to receive a limb-sparing resection plus adjuvant radiation therapy. The limb-sparing resection group received wide local excision followed by 5000 rads to the entire anatomic area at risk for local spread and 6000 to 7000 rads to the tumor bed. Both randomization groups received postoperative chemotherapy with doxorubicin (maximum cumulative dose 550 mg/m2), cyclophosphamide, and high-dose methotrexate. Twenty-seven patients randomized to receive limb-sparing resection and radiotherapy, and 16 received amputation (randomization was 2:1). There were four local recurrences in the limb-sparing group and none in the amputation group (p1 = 0.06 generalized Wilcoxon test). However, there were no differences in disease-free survival rates (71% and 78% at five years; p2 = 0.75) or overall survival rates (83% and 88% at five years; p2 = 0.99) between the limb-sparing group and the amputation treatment groups. Multivariate analysis indicated that the only correlate of local recurrence was the final margin of resection. Patients with positive margins of resection had a higher likelihood of local recurrence compared with those with negative margins (p1 less than 0.0001) even when postoperative radiotherapy was used. A simultaneous prospective randomized study of postoperative chemotherapy in 65 patients with high-grade soft-tissue sarcomas of the extremities revealed a marked advantage in patients receiving chemotherapy compared with those without chemotherapy in three-year continuous disease-free (92% vs. 60%; p1 = 0.0008) and overall survival (95% vs. 74%; p1 = 0.04). Thus limb-sparing surgery, radiation therapy, and adjuvant chemotherapy appear capable of successfully treating the great majority of adult patients with soft tissue sarcomas of the extremity.

Age-related changes in EGF and protease in submandibular glands of C57BL/6J mice

The submandibular glands of male C57BL/6J mice were studied cytologically and chemically at the following ages (months): 1-1.5, 6-8, 12-13, 28-32. The relative proportion of granular convoluted tubules (GCT), as well as the size and content of secretion granules of GCT cells, progressively increased throughout the first year of life. Correspondingly, the concentration within the glands of two GCT cell products, epidermal growth factor (EGF) and protease, also steadily increased. In senescent glands, GCTs formed relatively less of the gland parenchyma and were composed of shorter cells with reduced amounts of secretory granules. The concentration of EGF was reduced to 17% of its peak value at one year, while protease activity declined to 50% of its peak value. These morphologic and chemical findings imply a functional impairment in submandibular glands of the mouse with senescence.

Lithium carbonate and granulocyte production: dose optimization

To determine the optimal dose of lithium for inducing granulocytosis, the authors administered lithium carbonate to normal volunteers at five dose levels. The authors performed assessments of circulating and marginated blood pools of granulocytes and of marrow reserve granulocytes to confirm that the early granulocytosis following lithium administration is due to increased granulocyte production rather than redistribution. At 300 mg/day and 600 mg/day, lithium had no significant effect on granulocyte production. Doses of 900, 1200, and 1500 mg/day, corresponding to lithium levels of 0.55 to 1.50 mEq/liter, were associated with increased granulocyte production. Within this therapeutic range, no correlation between lithium level and granulocyte production was demonstrated. This study suggests that any lithium dose which achieves a lithium level of greater than 0.55 mEq/liter, i.e., doses greater than or equal to 900 mg/day, is adequate to induce granulocytosis. While lithium did not increase platelet production, doses of 900 mg/day to 1500 mg/day were associated with decreased bleeding times.

A study of patients with psychosocial problems in a family practice

This study was conducted to test the hypothesis that family practice patients with intrapersonal psychosocial problems are likely to be identified as having more health problems in general than patients not afflicted in this way. A second general objective of the study was to provide a health profile of patients having intrapersonal problems as compared with patients who do not. The total number of patients identified as having intrapersonal problems was 321 patients, 30.5 percent of this teaching practice population, but for purposes of the study a small sample (n = 94) was randomly selected. A control group was randomly selected from patients matched by age and sex in the practice. Study group patients were found to have a significantly greater number of family problems, hospital admissions, major surgical procedures, number of visits to the practice, gastrointestinal disorders, and illness due to inflammatory causes when compared to controls. This group was also found to have received more psychiatric care, more attention from allied health professionals, and more frequent psychotropic drugs. This study suggests that family physicians care for a cohort of patients with a high frequency of psychosocial problems and that these patients have an increased use of health care services.

Computed tomographic evaluation of laryngeal neoplasms

Nineteen patients with laryngeal lesions each underwent diagnostic studies consisting of laryngoscopy and computed tomography (CT). Sixteen patients had linear tomography and coronal and sagittal reconstruction of their transaxial CT images. The results of each examination were compared with the surgical and pathological findings to assess their relative value. The results confirmed previous reports of the accuracy and value of transaxial CT and direct laryngoscopy, but indicated that coronal and sagittal reconstruction as well as linear tomography added no significant information.

Sterile host yeasts (SHY): a eukaryotic system of biological containment for recombinant DNA experiments

A system of biological containment for recombinant DNA experiments in Saccharomyces cerevisiae (Brewer's/Baker's yeast) is described. The principle of containment is sterility: the haploid host strains all contain a mating-type-non-specific sterile mutation. The hosts also contain four auxotrophic mutations suitable for selection for the various kinds of vectors used. All vectors are derivatives of pBR322 which can be selected and maintained in both yeast and Escherichia coli. The system has recently been certified at the HV2 level by the National Institutes of Health.

The role of religious institutions in evangelization

Religious institutions are called to make an exodus out of their own holy land into the true holy land of humankind. By reflecting on the Beatitudes and Jesus' humanity, Catholic-sponsored health care institutions can better understand the meaning of evangelization.

Hyperparathyroidism--a reversible cause of cimetidine-resistant gastric hypersecretion

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Discrimination of infants' cry-signals

A technique for clustering infants' cry-signals on the basis of perceptually discriminable acoustic characteristics is reported. A cry-sequence containing all pairwise combinations of 24 signals was constructed. These signals have been used previously in cry-recognition studies (e.g., Wasz-Hockert, et al., 1968) and consist of six each of pain, hunger, pleasure, and birth. 20 musically competent subjects were tested individually and instructed to compare each cry with the one immediately preceding it in the sequence. Forced-choice "similarity" scores were summed for every pair of cries. These "similarity scores" were data for both a manual and a computerized clustering method. There was absolute agreement between these two methods, and the clusters of cry-signals correspond very closely to the four original cry groups. This seems a valid technique for examining the acoustic similarity of infants' cry-signals.

Erythrocyte membrane lipids in Friedreich's ataxia

In a study of the lipid composition of erythrocyte membranes in Friedreich's ataxia, the concentration of the major membrane components (phospholipids, cholesterol and protein) in ataxic patients, family members, and control subjects were found to be the same. The total fatty acid distribution was also normal. However, an altered distribution of phospholipid classes in erythrocytes was noted (an increase of PI + PS and a decrease of PE in Friedreich's ataxia patients).

Unfolding and refolding occur much faster for a proline-free proteins than for most proline-containing proteins

The kinetics for unfolding and refolding of a parvalbumin (band 5) have been examined as a function of pH near the transition region, using stopped-flow techniques. This protein is rather unusual in that it has no proline residues, and therefore serves as a good example to test the hypothesis that the rate-limiting step seen in denaturation reactions is due to the cis-trans isomerization of proline peptide bonds in the denatured state. The kinetics for parvalbumin unfolding and refolding are complex, with the data being resolvable into two fast phases at 25 degrees. The slower of the two phases seen for the parvalbumin is about 100 to 500 times faster than the slow phase seen for proline-containing proteins under the same conditions! These results argue strongly in support of the proline isomerization hypothesis. It is also suggested that the slower phase seen for parvalbumin and the second-slowest phase seen for proline-containing proteins might be due to the cis-trans isomerization of peptide bonds of non-proline residues.

Prognostic value of infranodal conduction time in patients with chronic bundle branch block

His bundle recordings were obtained in 121 patients with chronic bundle branch block and the patients were followed for a mean period of 18 months. Seventy-nine patients had an infranodal conduction time (H-Q) less than 70 msec while 42 had H-Q greater than or equal to 70 msec. There was no significant difference in mean age, smoking history, diabetes, syncope, dizziness, blood pressure, and serum cholesterol or triglyceride levels between the two groups. There was a significantly greater incidence of progresssion to second degree or third degree atrioventricular block (9/42, 21%), and of severe congestive heart failure (16/42, 38%) in patients with H-Q greater than or equal to 70 compared with those with H-Q less than 70 (1/79, 1.3%; and 13/79, 16%, respectively). The risk of sudden death was significantly greater only in the group with H-Q greater than or equal to 70 and severe congestive heart failure. There was no correlation between the presence of first degree atrioventricular block and/or any particular type of bundle branch block pattern with sudden death and/or progression to second degree or third degree atrioventricular block. Analysis of the surface electrocardiogram is only of limited value in predicting high risk patients with chronic bundle branch block. Electrophysiologic studies are of greatest value in patients with bundle branch block with transient neurologic symptoms in whom no cause for the symptoms is evident.

Pigment binding of copper in human bile

The copper profile of human bile was studied using a Cu-free preparative polyacrylamide gel system. 85 percent and 91 percent of the Cu in the bile of two subjects was found in a leading pigmented band with no additional detectable copper in the remainder of the gel in either subject. The content of the pigmented band was recovered from the gel by an intermediate electrophoretic technique. Subsequent n-butanol extraction removed contaminating bile salts with the formation of a Cu containing pigmented precipitate. Using thin-layer cellulose chromatography this precipitate was separated into two pigments which on the basis of color and diazotization reaction were believed to be conjugated bilirubins. Addition of Cu transformed the pigments into biochemically different species. 64Cu verified copper binding by the altered pigments.

Consideration of the Possibility that the slow step in protein denaturation reactions is due to cis-trans isomerism of proline residues

A model is proposed to account for the observation that the denaturation of small proteins apparently occurs in two kinetic phases. It is suggested that only one of these phases--the fast one--is actually an unfolding process. The slow phase is assumed to arise from the cis-trans isomerism of proline residues in the denaturated protein. From model compound data, it is shown that the expected rate for isomerism is in satisfactory agreement with the rates actually observed for protein folding. It is also shown that a simple model of protein unfolding based on the isomerism concept is very successful in accounting for many known experimental characteristics of the kinetics and thermodynamic of protein denaturation. Thus, the model is able to predict that two kinetic phases will be seen in the transition region while none are seen in the base-line regions, that both the fast and slow refolding phases lead to the native protein as the product, that the fast phase becomes the only observable phase for jumps ending far in the denatured base-line region, that most or all small proteins show a limiting low-temperature activation energy of ca. 20,000 cal, and that the relaxtion time for the slow phase seen in cytochrome c denaturation is much shorter than for all other small proteins. By utilizing "double-jump" experiments, it is shown directly that the slow phase is not part of the unfolding process but that it corresponds to a transition among two or more denatured forms which have identical spectroscopic (286.5 nm) properties. Thus, the slow relaxation is "invisible" except in the transition region where it couples to the fast unfolding equilibrium. Finally, since the present model assumes that only one of the major kinetic phases seen in denaturation reactions is concerned with the denaturation process per se, it is in agreement with numerous thermodynamic studies which show consistency with the two-state model for unfolding.