The collagen types in the attachment zone of rotator cuff tendons in the elderly: an immunohistochemical study

OBJECTIVE

The attachment zone of the rotator cuff tendons in the elderly was studied immunohistochemically in order to determine how degenerative changes affected the pattern of collagen fiber distribution.

METHODS

Twenty-seven cuffs with their bony insertion were obtained from 22 postmortem cases of both sexes ranging in age from 52 to 90 years and without a history of shoulder ailments. In addition, 3 cuff specimens from cadavers in the 3rd and 4th decades were examined for comparison. Sections of formalin fixed tissues were stained by peroxidase antiperoxidase (PAP) technique using monoclonal antibodies against types I, II and III collagen.

RESULTS

Degenerative changes affecting the fibrocartilage primarily were characterized by calcification, fibrovascular proliferation and microtears. In addition, they were found in all the cuff tendons of elderly individuals but not in those from younger subjects. Immunohistochemically, the attachment zone in areas without degenerative lesions showed collagen type I labelling strongly in bone but only moderately in the fibrocartilage. The predominant labelling in the fibrocartilage was for collagen type II, and collagen type III labelled principally in perichondrocytic areas. The tide-mark showed inconsistent labelling for any of the collagen types. In the presence of degenerative lesions, the disposition of fiber types was interrupted by calcification and microtears. Collagen type II composition of the fibrocartilage was markedly altered by the presence of fibrovascular tissue which labelled only for collagen type III.

CONCLUSION

We conclude that severe degenerative changes in the cuff tendons of elderly individuals, alter the collagen characteristic of the rotator cuff and that the changes could be associated with impairment of biomechanical properties of the attachment zone, and may give rise to the clinical syndrome of enthesopathy.

Immunohistochemical distribution of type I, II and III collagens in the rabbit supraspinatus tendon insertion

The collagen fibres in the area of attachment of the supraspinatus tendon to bone were studied immunohistochemically in 12 mature female New Zealand white rabbits. The labelling of type I collagen was uniformly prominent in the bone as well as in the fascicles of the tendon proper but inconspicuously scattered in the unmineralised and mineralised zones of the fibrocartilage. Type II collagen, not detected in the tendon proper, was widespread in both zones of the fibrocartilage. Type III collagen, on the other hand, appeared to be confined mainly to the zone of unmineralised fibrocartilage, in addition to its presence in the endotenon of the tendon proper. The region of the tidemark failed to show immunostaining for any of the collagen fibre types. In conclusion, this study demonstrates that, although all the principal fibrous collagen types are constituents of the supraspinatus tendon at its attachment site, the distribution pattern of immunolabelling varies from zone to zone.

[The effect of modified sham-feeding on gastrin-stimulated gastric secretion in patient with duodenal ulcer]

Patients with duodenal ulcer were classified into responders to H2-receptor antagonist and non-responders in whom duodenal ulcer did not heal within three months with the antagonist. In these patients and healthy controls, modified sham-feeding (MSF) test was performed to elucidate the pathophysiological differences between these groups, especially vagal activity of acid output. After tetragastrin 4 micrograms/kg/hr infusion for one hour, MSF was superimposed to the infusion (G + MSF). The acid output of non-responders (8 cases) and controls (8 cases) significantly increased in G + MSF. On the other hand, the acid output of responders (6 cases) significantly decreased. The acid output of non-responders in G + MSF was also significantly higher than that of controls. The results suggest that vagal activity of non-responders is higher than responders, and that there is disturbance of inhibitory mechanism in vagal system.

Characteristics of spermidine uptake by isolated rat enterocytes

Eukaryotic cells require polyamines for growth. The supply of polyamines to growing cells may be increased either by new synthesis or increased uptake. We have recently shown that putrescine uptake by isolated rat enterocytes is energy dependent, saturable, and ouabain insensitive. Although putrescine uptake was inhibited by putrescine and cadaverine, it was not inhibited by equal concentrations of spermine and spermidine. These data indicated that a carrier mechanism separate from that putrescine existed for spermidine and spermine. In the current study spermidine uptake by isolated enterocytes was saturable, temperature dependent, and inhibited by 1 mM KCN. Kinetic analysis resulted in a Km = 2.51 x 10(-6) M and a Vmax = 3.57 x 10(-12) mol.10(6) cells-1.15 min-1. Spermidine uptake was 70% inhibited by 1 mM ouabain. Replacement of sodium by choline, lithium, tetramethylammonium, or N-methyl-D-glucamine also inhibited spermidine uptake. Replacement of Na+ by mannitol or sucrose, however, depressed uptake but not significantly. Spermidine uptake was inhibited by 1 mM ouabain. Spermidine uptake was inhibited by relatively low concentrations of spermine and high concentrations of putrescine; while putrescine uptake was inhibited by relatively high concentrations of both spermine and spermidine. Kinetic data indicated that spermidine and spermine share a carrier that is distinct from the one mediating the uptake of putrescine. While spermidine uptake does not appear to depend on Na+ cotransport, it may be dependent on the electrical gradient established by the Na+-K+-ATPase.

Characteristics of putrescine uptake in isolated rat enterocytes

Polyamines are necessary for the growth of eukaryotic cells and are supplied either by new synthesis or cellular uptake. To our knowledge, no information is available on polyamine uptake by gastrointestinal cells. In the current study, isolated villous enterocytes from the rat accumulated putrescine to an eightfold concentration gradient. Uptake was temperature dependent, saturable, and inhibited by 1 mM KCN. Kinetic analysis showed a Km of 1.23 X 10(-5) M and a Vmax of 2.60 X 10(-10) mol.10(6) cells-1.15 min-1. Enterocytes from the distal one-fourth of the gut showed the highest rate of uptake. Putrescine uptake was inhibited by cadaverine and spermine but not by the amino acids asparagine, AIB, or leucine. Sodium replacement by choline, lithium, N-methyl-D-glucamine, or tetramethylammonium significantly inhibited uptake, but replacement of Na+ by sucrose or mannitol was without effect. The inhibition observed was believed to be due to the ability of the cations to interact in some way with the carrier. Neither ouabain nor digitoxigenin had any effect on uptake. These data indicate that putrescine is accumulated by villous enterocytes by a carrier-mediated process that does not appear to involve Na+ contransport.

Cyclic AMP in gastric juice does not reflect histamine H2 receptor activity in Heidenhain pouch dog

It is strongly believed that cAMP mediates histamine H2 receptor activity, but does not mediate gastrin and acetylcholine stimulation of gastric acid secretion. Therefore, cAMP production could be a marker of H2 receptor activity. Whether endogenous histamine mediates gastrin and/or acetylcholine stimulation, at least partially, remains to be elucidated. If cAMP in the gastric juice reflects H2 receptor activity, we can investigate whether endogenous histamine mediates gastrin and/or acetylcholine stimulation in vivo. In this study, we investigated whether cAMP in the gastric juice reflected histamine H2 receptor activity in the Heidenhain pouch dog in vivo using different kinds of inhibitors of gastric secretion. Our hypothesis was as follows: Upon betazole stimulation, cimetidine, an H2 receptor antagonist, should decrease cAMP output into the gastric juice, but omeprazole, an H+, K+-ATPase blocker, should not, because it blocks at a site more peripheral than the H2 receptor and the production of cAMP. Sixty minutes after betazole administration, 4.0 mumol/kg of cimetidine and 0.18 mumol/kg omeprazole were administered intravenously and they inhibited gastric juice volume to a similar degree, that is, 49.6% and 52.1%, respectively. However, omeprazole caused a greater decrease in cAMP output than cimetidine. Inhibition with 4 mumol/kg/h of cimetidine or 0.2 mumol/kg of omeprazole from the beginning of betazole stimulation also caused similar decreases in gastric juice volume, 66.6% and 60.6%, respectively. Both inhibitors decreased cAMP output into the gastric juice in a similar fashion in the first two 30 minute periods. These results do not agree with our hypothesis.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of carbonic anhydrase in gastric mucosal protection with special reference to H+ back diffusion and concomitant metabolic acidosis induced by acetazolamide

It is suggested that carbonic anhydrase is implicated not only in gastric acid secretion, but in mucosal protection. It was reported that acetazolamide induced gastric mucosal lesions. But acetazolamide also caused concomitant metabolic acidosis by inhibiting H+ secretion from renal tubules. We investigated whether concomitant metabolic acidosis is implicated in gastric mucosal lesions induced by acetazolamide in vivo. We also evaluated the effect of acetazolamide on gastric H+ back diffusion in vivo. Correction of metabolic acidosis with sodium bicarbonate had no effect on the degree of the gastric mucosal lesions. Acetazolamide caused no change in gastric H+ and Na+ flux. These results suggest that metabolic acidosis induced by acetazolamide is not implicated in gastric mucosal lesions. Carbonic anhydrase has no effect on H+ back diffusion but may be implicated in mucosal protection by the disposition of back diffused H+ into the gastric mucosa.

Evaluation of the new giant-biopsy forceps in the diagnosis of mucosal and submucosal gastric lesions

In order to improve the diagnosis of gastric disorders on the basis of biopsy material, we devised larger biopsy forceps (5 mm X 2.5 mm in inside dimensions) which fit into the newer fibergastroscope, GIF-1T (Olympus). Samples from 116 cases yielded 276 specimens; 179 specimens (64.8%) showed the full-thickness of the mucosa with muscularis mucosae, and approximately one-third of the total specimens included a considerable amount of submucosal tissue, but none of them contained parts of muscularis propria. In 4 out of 36 gastric carcinoma cases there was inconsistency between endoscopic and histological recognition of the proximal border of carcinomatous infiltration. Differentiation between adenoma and IIa, and benign and malignant lymphoma were more feasible with our forceps. No complications apart from minor bleeding were seen.

In vitro regeneration of resting lymphocytes from stimulated lymphocytes and its inhibition by insulin

Concanavalin A- (Con A) stimulated mouse lymphocytes were separated from unstimulated cell populations by a bovine serum albumin (BSA) density gradient centrifugation 2 days after the stimulation. The stimulated cells divided, but did not initiate a new round of DNA replication when cultured further in the absence of Con A. The divided cells became similar in various properties to unstimulated lymphocytes during a prolonged incubation, suggesting that they entered the resting state. In the present study, the process toward the resting state of lymphocytes from the proliferating state was manifested by: a) a decrease in a cell volume, b) lowering of protein content, c) a loss of responsiveness to T cell growth factor (Interleukin 2) (TCGF(IL2)) probably as a result of disappearance of TCGF(IL2) receptors, d) disappearance of insulin receptors, and e) a duration of time lag between the addition of Con A and the onset of DNA synthesis. In addition, it was found that insulin was not mitogenic for recently divided lymphocytes, but prevented these cells from entering the resting state. This suggests that there may be an in vivo system that keeps stimulated lymphocytes highly responsive to antigens for at least several days without initiating DNA synthesis and cell division.

In vitro regeneration of resting lymphocytes from stimulated lymphocytes and its inhibition by insulin

Concanavalin A- (Con A) stimulated mouse lymphocytes were separated from unstimulated cell populations by a bovine serum albumin (BSA) density gradient centrifugation 2 days after the stimulation. The stimulated cells divided, but did not initiate a new round of DNA replication when cultured further in the absence of Con A. The divided cells became similar in various properties to unstimulated lymphocytes during a prolonged incubation, suggesting that they entered the resting state. In the present study, the process toward the resting state of lymphocytes from the proliferating state was manifested by: a) a decrease in a cell volume, b) lowering of protein content, c) a loss of responsiveness to T cell growth factor (Interleukin 2) (TCGF(IL2)) probably as a result of disappearance of TCGF(IL2) receptors, d) disappearance of insulin receptors, and e) a duration of time lag between the addition of Con A and the onset of DNA synthesis. In addition, it was found that insulin was not mitogenic for recently divided lymphocytes, but prevented these cells from entering the resting state. This suggests that there may be an in vivo system that keeps stimulated lymphocytes highly responsive to antigens for at least several days without initiating DNA synthesis and cell division.

Dessociation and reconstitution of colicin E3 and immunity substance complex

It has recently been found that so-called native colicin E3, which has been used for studies of its mode of action, is a complex of two kinds of proteins. The complex could be dissociated into the two components in SDS. These components were isolated by gel filtration of 1% SDS followed by treatment with Sowex-2 to remove bounds SDS. One component, characterized by its low molecular weight, prevented colicin E3-induced inhibition of poly(U)-dependent protein synthesis and was designated as immunity substance. The other component (protein A), which was of high molecular weight, had 100-fold higher in vitro ribosome-inactivating activity than native colicin E3, but had lower bacteriocidal activity. Colicin E3 was reconstituted from the two isolated protein components. The reconstituted colicin E3, when compared with protein A, showed a decrease in in vitro activity (inhibition of poly(U)-dependent protein synthesis), but had higher bacteriocidal activity in vivo. Thus complex formation of protein A with immunity substance should play and important role in the bacteriocidal action, but protein A itself might inactivate ribosomes in the interior of the sensitive cells.