Identification and enzymatic characterization of two diverging murine counterparts of human interstitial collagenase (MMP-1) expressed at sites of embryo implantation

Remodeling of fibrillar collagen in mouse tissues has been widely attributed to the activity of collagenase-3 (matrix metalloproteinase-13 (MMP-13)), the main collagenase identified in this species. This proposal has been largely based on the repeatedly unproductive attempts to detect the presence in murine tissues of interstitial collagenase (MMP-1), a major collagenase in many species, including humans. In this work, we have performed an extensive screening of murine genomic and cDNA libraries using as probe the full-length cDNA for human MMP-1. We report the identification of two novel members of the MMP gene family which are contained within the cluster of MMP genes located at murine chromosome 9. The isolated cDNAs contain open reading frames of 464 and 463 amino acids and are 82% identical, displaying all structural features characteristic of archetypal MMPs. Comparison for sequence similarities revealed that the highest percentage of identities was found with human interstitial collagenase (MMP-1). The new proteins were tentatively called Mcol-A and Mcol-B (Murine collagenase-like A and B). Analysis of the enzymatic activity of the recombinant proteins revealed that both are catalytically autoactivable but only Mcol-A is able to degrade synthetic peptides and type I and II fibrillar collagen. Both Mcol-A and Mcol-B genes are located in the A1-A2 region of mouse chromosome 9, Mcol-A occupying a position syntenic to the human MMP-1 locus at 11q22. Analysis of the expression of these novel MMPs in murine tissues revealed their predominant presence during mouse embryogenesis, particularly in mouse trophoblast giant cells. According to their structural and functional characteristics, we propose that at least one of these novel members of the MMP family, Mcol-A, may play roles as interstitial collagenase in murine tissues and could represent a true orthologue of human MMP-1.

Growth hormone and nutrition as protective agents against methotrexate induced enteritis

OBJECTIVE

To determine whether exogenously administered growth hormone can reduce or prevent chemotherapy-induced intestinal mucosa injury. The expected results will allow to consider its potential clinical use.

DESIGN

Experimental and randomized study.

SETTING

Experimental Surgery Service, La Paz University Hospital.

SUBJECTS

Adult Wistar rats weighing 250-300 g.

MATERIALS AND METHODS

A chemotherapy protocol with methotrexate (MTX) (120 mg/kg) was employed. Animals fed either with a normoproteic or a hyperproteic liquid diet were treated with either saline or growth hormone (1 mg/kg/day) since three days before until four days after chemotherapy. Animals were sacrificed seven days after MTX administration for tissue sampling.

RESULTS

Co-administration of growth hormone and a hyperproteic diet increased intestinal crypt proliferation and reduced MTX-induced apoptosis.

CONCLUSIONS

Jejunal mucosal structure (morphometry), proliferation (Ki-67) and apoptosis (TUNNEL) were assessed.

Collagen metabolism is markedly altered in the hypertrophic cartilage of growth plates from rats with growth impairment secondary to chronic renal failure

Skeletal growth depends on growth plate cartilage activity, in which matrix synthesis by chondrocytes is one of the major processes contributing to the final length of a bone. On this basis, the present work was undertaken to ascertain if growth impairment secondary to chronic renal insufficiency is associated with disturbances of the extracellular matrix (ECM) of the growth plate. By combining stereological and in situ hybridization techniques, we examined the expression patterns of types II and X collagens and collagenase-3 in tibial growth plates of rats made uremic by subtotal nephrectomy (NX) in comparison with those of sham-operated rats fed ad libitum (SAL) and sham-operated rats pair-fed with NX (SPF). NX rats were severely uremic, as shown by markedly elevated serum concentrations of urea nitrogen, and growth retarded, as shown by significantly decreased longitudinal bone growth rates. NX rats showed disturbances in the normal pattern of chondrocyte differentiation and in the rates and degree of substitution of hypertrophic cartilage with bone, which resulted in accumulation of cartilage at the hypertrophic zone. These changes were associated with an overall decrease in the expression of types II and X collagens, which was especially marked in the abnormally extended zone of the hypertrophic cartilage. Unlike collagen, the expression of collagenase-3 was not disturbed severely. Electron microscopic analysis proved that changes in gene expression were coupled to alterations in the mineralization as well as in the collagen fibril architecture at the hypertrophic cartilage. Because the composition and structure of the ECM have a critical role in regulating the behavior of the growth plate chondrocytes, results obtained are consistent with the hypothesis that alteration of collagen metabolism in these cells could be a key process underlying growth retardation in uremia.

Bronchial sensitivity to histamine in former asthmatics: redevelopment of symptoms during a year of followup

The aim of this protocol was to study bronchial responsiveness in 23 former asthmatics who were free of symptoms for at least 5 years. Bronchial hyperreactivity (BHR) was evaluated with histamine challenge test and the results were compared with those of 20 normal subjects and 20 current asthmatic patients. Among the former asthmatics 65% fulfilled the criteria of BHR. During 1 year of followup, two former asthmatics redeveloped asthma symptoms. Interestingly, one patient had no BHR when initially tested. These findings suggest that the absence of BHR does not guarantee the nonrecurrence of asthma symptoms in former asthmatics.

Distribution of choline acetyltransferase immunoreactivity in the brain of an elasmobranch, the lesser spotted dogfish (Scyliorhinus canicula)

Although the distribution of cholinergic cells is remarkably similar across the vertebrate species, no data are available on more primitive species, such as cartilaginous fishes. To extend the evolutionary analysis of the cholinergic systems, we studied the distribution of cholinergic neurons in the brain and rostral spinal cord of Scyliorhinus canicula by immunocytochemistry using an antibody against the enzyme choline acetyltransferase (ChAT). Western blot analysis of brain extracts of dogfish, sturgeon, trout, and rat showed that this antibody recognized similar bands in the four species. Putative cholinergic neurons were observed in most brain regions, including the telencephalon, diencephalon, cerebellum, and brainstem. In the retrobulbar region and superficial dorsal pallium of the telencephalon, numerous small pallial cells were ChAT-like immunoreactive. In addition, tufted cells of the olfactory bulb and some cells in the lateral pallium showed faint immunoreactivity. In the preoptic-hypothalamic region, ChAT-immunoreactive (ChAT-ir) cells were found in the preoptic nucleus, the vascular organ of the terminal lamina, and a small population in the caudal tuber. In the epithalamus, the pineal photoreceptors were intensely positive. Many cells of the habenula were faintly ChAT-ir, but the neuropil of the interpeduncular nucleus showed intense ChAT immunoreactivity. In the pretectal region, ChAT-ir cells were observed only in the superficial pretectal nucleus. In the brainstem, the somatomotor and branchiomotor nuclei, the octavolateral efferent nucleus, and a cell group just rostral to the Edinger-Westphal (EW) nucleus contained ChAT-ir neurons. In addition, the trigeminal mesencephalic nucleus, the nucleus G of the isthmus, some locus coeruleus cells, and some cell populations of the vestibular nuclei and of the electroreceptive nucleus of the octavolateral region exhibited ChAT immunoreactivity. In the reticular areas of the brainstem, the nucleus of the medial longitudinal fascicle, many reticular neurons of the rhombencephalon, and cells of the nucleus of the lateral funiculus were immunoreactive to this antibody. In the cerebellum, Golgi cells of the granule cell layer and some cells of the cerebellar nucleus were also ChAT-ir. In the rostral spinal cord, ChAT immunoreactivity was observed in cells of the motor column, the dorsal horn, the marginal nucleus (a putative stretch-receptor organ), and in interstitial cells of the ventral funiculus. These results demonstrate for the first time that cholinergic neurons are distributed widely in the central nervous system of elasmobranchs and that their cholinergic systems have evolved several characteristics that are unique to this group.

ADAM 23/MDC3, a human disintegrin that promotes cell adhesion via interaction with the alphavbeta3 integrin through an RGD-independent mechanism

ADAM 23 (a disintegrin and metalloproteinase domain)/MDC3 (metalloprotease, disintegrin, and cysteine-rich domain) is a member of the disintegrin family of proteins expressed in fetal and adult brain. In this work we show that the disintegrin-like domain of ADAM 23 produced in Escherichia coli and immobilized on culture dishes promotes attachment of different human cells of neural origin, such as neuroblastoma cells (NB100 and SH-S(y)5(y)) or astrocytoma cells (U373 and U87 MG). Analysis of ADAM 23 binding to integrins revealed a specific interaction with alphavbeta3, mediated by a short amino acid sequence present in its putative disintegrin loop. This sequence lacks any RGD motif, which is a common structural determinant supporting alphavbeta3-mediated interactions of diverse proteins, including other disintegrins. alphavbeta3 also supported adhesion of HeLa cells transfected with a full-length cDNA for ADAM 23, extending the results obtained with the recombinant protein containing the disintegrin domain of ADAM 23. On the basis of these results, we propose that ADAM 23, through its disintegrin-like domain, may function as an adhesion molecule involved in alphavbeta3-mediated cell interactions occurring in normal and pathological processes, including progression of malignant tumors from neural origin.

[Effect of low calcitonin doses on bone remodeling in postmenopausal women with high bone turnover rate]

BACKGROUND

Calcitonin is specially indicated for the treatment of osteoporosis in women that cannot receive estrogen replacement therapy or that have a high bone turnover rate.

AIM

To study the effects of low intranasal calcitonin doses on bone remodeling in postmenopausal women with a high bone turnover.

PATIENTS AND METHODS

Forty one healthy women aged 56 +/- 6 years old, with a mean lapse after menopause of 7.6 +/- 6.5 years and with a high bone turnover rate, evidenced by an urinary hydroxyproline (mg/dl)/creatinine (g/dl) ratio of 52.4 +/- 7.2, were studied. They were randomly assigned to receive 100 or 50 U/calcitonin thrice a week during 3 months or to a control group that received placebo. All received 500 mg/day calcium carbonate. Urinary hydroxyproline/creatinine ratio was measured a 0, 15, 30, 60 and 90 days. Plasma bone fraction of alkanine phosphatases was measured at 0, 30 and 90 days.

RESULTS

Initial urinary hydroxyproline/creatinine ratio and plasma bone fraction of alkanine phosphatases were similar in all study groups and there was no change in these parameters during the study period.

CONCLUSIONS

Intranasal calcitonin in doses of 100 U thrice a week or less, does not modify accelerated bone turnover in postmenopausal women.

Tribenzylphosphine oxide

The title compound, (C(6)H(5)CH(2))(3)PO, is an organic tertiary phosphine oxide. The molecule has threefold symmetry, with the P-O bond along the threefold axis. Main dimensions include P-O 1.488 (4), P-C 1.823 (3) A and O-P-C 114.7 (1) degrees. The crystals were accidentally obtained when preparing complexes of nickel(II) with dibenzylphosphine.

[Bone turnover in lactating adolescent: evaluation at the end of pregnancy, during and after the weaning period]

BACKGROUND

There is paucity of information about bone metabolism during pregnancy or breast feeding in teenagers.

AIM

To study bone turnover at the end of pregnancy and during breast feeding in teenagers and correlate it with environmental, hormonal or nutritional variables.

SUBJECTS AND METHODS

Thirty teenagers during their breast feeding period after a first pregnancy and 30 nulliparous girls matched for age, age of menarche and body mass index were assessed three weeks after delivery (period 1), at six months of breast feeding (period 2) and one year after the lactating period (period 3). Calcium intake and plasma calcium, phosphorus, alkaline phosphatases, parathormone, estradiol and prolactin were measured. Calcium, creatinine and hydroxyproline were also measured in a morning urine sample.

RESULTS

Lactating and control girls were aged 16.3 +/- 0.8 and 16.1 +/- 0.7 years old respectively. Calcium intake in lactating and control girls was 798 +/- 421 and 640 +/- 346 g/day respectively in period 1, 612 +/- 352 and 592 +/- 309 mg/day in period 2 and 495 +/- 180 and 456 +/- 157 g/day in period 3. During periods 1 and 2, lactating girls had higher alkaline phosphatases (161 +/- 37 compared to 119 +/- 28 U/l and 149 +/- 37 compared to 106 +/- 23 U/l), parathormone (4.3 +/- 2.6 compared to 2.8 +/- 0.8 ng/dl and 3.6 +/- 1.6 compared to 3.0 +/- 0.9 ng/dl) and urinary hydroxyproline (95 +/- 16 compared to 63 +/- 15 mg/g creatinine and 84 +/- 19 compared to 59 +/- 15 mg/g creatinine). No differences were observed in period 3. No correlation between bone turnover variables, body mass index or hormonal parameters, was observed.

CONCLUSIONS

In teenagers, there is an increase in bone turnover at the end of pregnancy, that persists during the lactating period. These changes are not related to nutritional or hormonal variables.

Different bone growth rates are associated with changes in the expression pattern of types II and X collagens and collagenase 3 in proximal growth plates of the rat tibia

Skeletal growth depends on endochondral ossification in growth plate cartilage, where proliferation of chondrocytes, matrix synthesis, and increases in chondrocyte size all contribute to the final length of a bone. To learn more about the potential role of matrix synthesis/degradation dynamics in the determination of bone growth rate, we investigated the expression of matrix collagens and collagenase 3 in tibial growth plates in three age groups of rats (21, 35, and 80 days after birth), each characterized by specific growth rates. By combining stereological and in situ hybridization techniques, it was found that the expression of matrix collagens and collagenase 3 was specifically turned on or off at specific stages of the chondrocyte-differentiation cycle, and these changes occurred as a temporal sequence that varied depending of animal growth rate. Furthermore, the expression of these matrix proteins by a growth plate chondrocyte was found to be sped up or slowed down depending of the growth rate. In addition to expression of types II and X collagen, collagenase-3 expression was found to constitute a constant event in the series of changes in gene expression that takes place during the chondrocyte-differentiation process. Collagenase-3 expression was found to show a biphasic pattern: it was intermittently expressed at the proliferative phase and uniformly expressed at the hypertrophic stage. An intimate relationship between morphological and kinetic changes associated with chondrocyte hypertrophy and changes in the expression pattern of matrix collagens and collagenase 3 was observed. Present data prove that the matrix synthesis/degradation dynamics of the growth plate cartilage varied depending on growth rate; these results support the hypothesis that changes in matrix degradation and synthesis are a critical link in the sequence of tightly regulated events that lead to chondrocytic differentiation.

Hepatic fibrogenic activity in chronic alcoholic pancreatitis

The prevalence and the mechanisms of hepatic fibrosis in chronic alcoholic pancreatitis remain uncertain. The aim of this study was to investigate the fibrogenic activity of the liver in patients with chronic pancreatitis and its relation with either the alcohol or cholestasis. Liver biopsies were obtained from 16 patients with chronic pancreatitis at the time of surgery and from 10 organ donors. Samples were processed for histologic examination to assess the presence and extent of fibrosis, inflammatory reactions, and cholestasis- and alcohol-related lesions. In other samples, the collagen content was measured by morphometry, and prolylhydroxylase activity was determined. Liver-function tests, ultrasonography, and endoscopic retrograde cholangiopancreatography were performed before surgery in all the patients. Of patients with chronic pancreatitis, 75% had significantly greater hepatic fibrosis and prolylhydroxylase activity than the control group. Moreover, prolylhydroxylase activity in patients with chronic pancreatitis was higher in those with cholestasis or partial obstruction of the common bile duct than in those without cholestasis or partial obstruction of the common bile duct. Both the fibrogenic activity and the collagen content in the livers of patients with chronic alcoholic pancreatitis are significantly increased, even in those without histologic lesions, and these alterations may be secondary to a partial occlusion of the common bile duct.

Norplant((R)) implants and progesterone vaginal rings do not affect maternal bone turnover and density during lactation and after weaning

Bone density and turnover was assessed in a longitudinal study of healthy lactating women who initiated use of Norplant((R)) implants (NOR, n = 29), progesterone vaginal rings (PVR, n = 28) or Copper T 380A intrauterine devices (T-Cu, n = 51, control group) around day 60 postpartum. Bone density, serum calcium, phosphorus, alkaline phosphatases, parathyroid hormone (PTH), follicle stimulating hormone (FSH), oestradiol and prolactin, and urinary hydroxyproline and creatinine were measured at postpartum months 1 (PM1), and 12 (PM12) and 6 or 12 months after weaning; at month 6 postpartum (PM6) serum and urine tests alone were performed. Baseline characteristics and lactation performance were similar between groups. Biochemical markers of bone turnover were higher at PM1, PM6 and PM12 than after weaning, with no differences between groups. Bone density in the lumbar spine (L2-L4) and femoral neck at PM1 and PM12 ( approximately 1.11 g/cm(2)) was similar in three groups. Lumbar spine values were found to be lower in lactating women than those present in non-lactating women, but increased after weaning to similar values. The two progestin-only contraceptives studied appear to have no deleterious effect upon bone density and metabolism in healthy lactating women.

Central retinal vein thrombosis associated with prothrombin 20210G/A gene variant

We describe a patient with central retinal vein thrombosis associated with the prothrombin gene 20210G/A. The associated risk factors and the patient's personal and family history of thrombosis are dealt with. In addition, the literature on the cases reported up to now is reviewed as is the prevalence of this new mutation in patients with central retinal vein thrombosis.

Collagenase 3 is a target of Cbfa1, a transcription factor of the runt gene family involved in bone formation

Collagenase 3 (MMP-13) is a recently identified member of the matrix metalloproteinase (MMP) gene family that is expressed at high levels in diverse human carcinomas and in articular cartilage from arthritic patients. In addition to its expression in pathological conditions, collagenase 3 has been detected in osteoblasts and hypertrophic chondrocytes during fetal ossification. In this work, we have evaluated the possibility that Cbfa1 (core binding factor 1), a transcription factor playing a major role in the expression of osteoblastic specific genes, is involved in the expression of collagenase 3 during bone formation. We have functionally characterized a Cbfa motif present in the promoter region of collagenase 3 gene and demonstrated, by cotransfection experiments and gel mobility shift assays, that this element is involved in the inducibility of the collagenase 3 promoter by Cbfa1 in osteoblastic and chondrocytic cells. Furthermore, overexpression of Cbfa1 in osteoblastic cells unable to produce collagenase 3 leads to the expression of this gene after stimulation with transforming growth factor beta. Finally, we show that mutant mice deficient in Cbfa1, lacking mature osteoblasts but containing hypertrophic chondrocytes which are also a major source of collagenase 3, do not express this protease during fetal development. These results provide in vivo evidence that collagenase 3 is a target of the transcriptional activator Cbfa1 in these cells. On the basis of these transcriptional regulation studies, together with the potent proteolytic activity of collagenase 3 on diverse collagenous and noncollagenous bone and cartilage components, we proposed that this enzyme may play a key role in the process of bone formation and remodeling.

[Detection of thyroglobulin autoantibodies and potential interference with serum thyroglobulin measurement]

BACKGROUND

Thyroglobulin measurement is useful for the follow up of patients subjected to total thyroidectomy for differentiated thyroid carcinoma. Thyroglobulin autoantibodies may interfere with its determination.

AIM

To measure thyroglobulin autoantibodies and their interference with thyroglobulin determination.

MATERIAL AND METHODS

The presence of thyroglobulin autoantibodies was investigated in 801 serum samples sent to the laboratory for measurement of thyroglobulin levels. A serum was considered positive for these autoantibodies when radioactivity corresponding to 125I-thyroglobulin bound to thyroglobulin autoantibodies, precipitated with human gamma globulin, exceeded in 1.4 times that of a negative sera pool. In positive sera, thyroglobulin autoantibody concentration was measured and its interference with thyroglobulin radioimmunoassay was assessed through a recuperation test using exogenous thyroglobulin.

RESULTS

Thyroglobulin autoantibodies were detected in 149 sera (18.6%). Of these, 65 had a recuperation that fluctuated between 1 and 80%. Thyroglobulin autoantibody concentration was negatively correlated with recuperation percentages (r = -0.64; p < 0.001) but not with thyroglobulin concentrations (r = 0.08). Thyroglobulin was higher in positive sera with a recuperation over 80% than in sera with a recuperation of less than 80% (12.7 +/- 1.7 and 5.9 +/- 0.6 ng/ml, respectively; p < 0.001).

CONCLUSIONS

Thyroglobulin autoantibodies interfere with thyroglobulin measurement by radioimmunoassay, sequestering variable amounts of thyroglobulin. The presence of these autoantibodies must be investigated prior to thyroglobulin determination.

Unusual fracture of distal third of the clavicle in a hockey player: case report and a new approach to treatment

Clavicle fractures represent 5% of all skeletal injuries, and the distal third of the clavicle is involved in approximately 10%-15% of all these fractures. The incidence of delayed union or non-union in Neer type II fractures of the distal third of the clavicle is high. The ideal treatment for Neer type II fractures of the distal third of the clavicle is still open to controversy. Several treatments have been proposed, but there is no consensus about the treatment of choice. The case reported here presents a unique type of fracture of the lateral end of the clavicle that, since a medial fragment is involved, is a Neer type II fracture, but because of the nature of the fracture line the coracoclavicular ligaments remained intact. Trans-bony suture between the two fracture fragments was performed as the only treatment. This treatment has not been previously described and, although it has just been used in a single case, it appears to be an effective, efficient and simple alternative for the treatment of Neer type II fractures of the distal third of the clavicle.

Growth plate cartilage formation and resorption are differentially depressed in growth retarded uremic rats

To characterize the modifications of growth plate in individuals with growth impairment secondary to chronic renal failure, young rats were made uremic by subtotal nephrectomy (NX) and, after 14 d, their tibial growth plates were studied and compared with those of sham-operated rats fed ad libitum (SAL) or pair-fed with NX (SPF). NX rats were growth retarded and severely uremic. Growth plate height (mean +/- SD) was much greater (P<0.05) in NX (868.4+/-85.4 microm) than SAL (570.1+/-93.5 microm) and SPF (551.9+/-99.7 microm) rats as a result of a higher (P<0.05) hypertrophic zone (661.0+/-89.7 versus 362.8+/-71.6 and 353.0+/-93.9 microm, respectively). The increased size of the growth plate was associated with a greater number of chondrocytes and modifications in their structure, particularly in the hypertrophic zone adjacent to bone. In this zone, chondrocytes of NX animals were significantly (P<0.05) smaller (12080.4+/-1158.3 microm3) and shorter (34.1+/-2.5 microm) than those of SAL (16302.8+/-1483.4 microm3 and 37.8+/-2.0 microm) and SPF (14465.8+/-1521.0 microm3 and 36.3+/-1.8 microm). The interface between the growth plate cartilage and the metaphyseal bone appeared markedly irregular in NX rats. Kinetics of chondrocytes was also modified (P<0.05) in the NX rats, which had lower cell turnover per column per day (5.4+/-0.9), longer duration of hypertrophic phase (89.0+/-15.2 h), and reduced cellular advance velocity (7.4+/-2.2 microm/h) compared with SAL (8.0+/-1.6, 32.1+/-6.7 h, and 11.3+/-2.7 microm/h) and SPF (7.2+/-1.1, 34.8+/-5.1 h, and 10.1+/-2.5 microm/h). Cell proliferation was no different among the three groups. Because the growth plates of SPF and SAL rats were substantially not different, modifications observed in the NX rats cannot be attributed to the nutritional deficit associated with renal failure. These findings indicate that chronic renal failure depresses both the activity of the growth plate cartilage by altering chondrocyte hypertrophy and the replacement of cartilage by bone at the metaphyseal end. The two processes are differentially depressed since cartilage resorption is more severely lowered than cartilage enlargement and this leads to an accumulation of cartilage at the hypertrophic zone.

Effect of four enteral foods on the small bowel of undernourished rats after midgut resection

OBJECTIVE

To describe the effects of new enteral foods on the adaptation of the gut mucosa after massive intestinal resection in rats.

DESIGN

Laboratory experiment.

SETTING

Teaching hospital, Spain.

SUBJECTS

91 male Wistar rats, 69 of which were studied (5 were excluded and 17 died).

INTERVENTIONS

Previously undernourished rats were subjected to either massive bowel resection (n = 30) or laparotomy (n = 26) and fed four enteral hypocaloric diets for 7 days: Alitraq (n = 7 in each group), Impact (n = 8 and 7), Enrich (n = 8 and 6), and Elemental (n = 7 and 6). The remainder were not operated on and fed chow (n = 7) or a diet containing no protein (n = 6). Two diets were high in protein (Alitraq and Impact) and two contained normal amounts (Enrich and Elemental).

MAIN OUTCOME MEASURES

Bowel mucosal thickness and proliferation; disaccharidase activity; intestinal weight and length; body weight; and plasma somatostatin, IGF-1, and peptide YY concentrations.

RESULTS

Enriched diets provided a higher body and intestinal weight, and increased length of jejunal and ileal villous size. Peptide concentrations were modified by resection but not by the diet given. Concentrations of somatostatin and insulin-like growth factor were reduced in all groups with the exception of somatostatin in the two diets high in protein in the sham-operated rats.

CONCLUSIONS

Enriched diets all improve the intestinal adaptive response to massive bowel resection in rats, offering advantages over diets with normal amounts of protein.

[Hyperthyroxinemia and clinical euthyroidism. Report of one case]

The association of hyperthyroxinemia and euthyroidism is frequent and characterized by high plasma thyroxin concentrations, normal TSH values and absence of clinical signs of hyperthyroidism. We report an asymptomatic 28 years old male presenting with a serum total plasma thyroxin of 18.5 micrograms/dl (N 6.1-12.5), a free thyroxin of 2.9 ng/dl (N 0.8-1.4), a TSH of 3.4 microIU/ml (N 0.5-5), and a triiodothyronine of 128 ng/dl (N 80-180). Laboratory assessment did not find high thyroxin binding globulin, albumin or prealbumin concentrations or antithyroxin antibodies. The thyroxin binding capacity of albumin was elevated to 58.2 micrograms/dl (N 11.5-34.1). TSH responded normally to TRH stimulus and was suppressed with exogenous triiodothyronine, which caused an hyperthyroid syndrome. We concluded that this patient had a familial dysalbuminemia.

Synthesis and degradation of collagen in pancreatic fibrogenesis

The mechanism of fibrogenesis in the pancreas is not well known. We analyzed the role of prolylhydroxylase and collagenase activities in the development of fibrosis in chronic alcoholic pancreatitis (CAP). Nineteen patients with CAP and 11 controls (organ donors) with normal pancreatic histology were included in the study. Pancreatic tissue was obtained from all subjects to measure (a) area of fibrosis (histomorphometric method); (b) prolylhydroxylase activity (PHase), which reflects the intracellular synthesis of collagen (Hutton's method); and (c) collagenase activity, which reflects the degradation of collagen (collagenase assay system, 3H). The percentage of the fibrosis area in relation to the total area of pancreatic tissue was significantly higher in CAP than in the control group (70.6+/-20.2% vs. 4.6+/-1.8%; p<0.001). Mean pancreatic PHase activity was also significantly higher in CAP than in the control group (775+/-258 cpm/mg protein/h vs. 405+/-151 cpm/mg protein/h; p<0.001). The collagenase activity was significantly lower in CAP than in the control group (8.7+/-3.5 cpm/cpm added/mg protein vs. 18.0+/-3.9 cpm/cpm added/mg protein; p<0.001). A significant correlation was observed between percentage fibrosis evaluated histomorphometrically and PHase activity in all patients (r = 0.72; p<0.001), and between PHase and collagenase activities in controls (r = 0.70; p = 0.024), but not in CAP. Pancreatic tissue in CAP has an increased fibrogenic activity and an impaired collagen-degradation capacity. These findings might explain the excessive development of fibrosis in CAP.

Collagenase-3 expression is associated with advanced local invasion in human squamous cell carcinomas of the larynx

Collagenase-3 (MMP-13) is a matrix metalloproteinase recently identified on the basis of differential expression in normal breast tissues and in breast carcinoma. To date, collagenase-3 expression has been reported only in breast carcinomas and in articular cartilage of arthritic patients; the presence and possible implication of this enzyme in the progression of other malignant tumours are unknown. In this study collagenase-3 mRNA expression has been analysed by northern blot in a series of 35 matched squamous cell carcinomas of the larynx and the corresponding adjacent non-neoplastic tissues. In addition, mRNA expression of membrane type 1-matrix metalloproteinase (MT1-MMP) and gelatinase A, two matrix metalloproteinases which have the ability to activate collagenase-3 in vitro, was also examined in the same cases. No collagenase-3 expression was detected in any of the 35 normal mucosae, but collagenase-3 mRNA was observed in 20 of the 35 carcinomas (57 per cent). Western blot analysis revealed the presence of collagenase-3 protein in those carcinomas with high levels of mRNA expression, whereas no protein was detected in the carcinomas with negative mRNA expression, or in any of the normal tissues. The protein was localized predominantly in tumour epithelial cells. Collagenase-3 expression correlated significantly with better histological differentiation of the tumours (p = 0.026), as well as with advanced local invasion (p = 0.026). Collagenase-3 upregulation was also significantly associated with MT1-MMP and gelatinase A overexpression. These findings suggest that collagenase-3 expression may contribute to the progression of a significant subset of squamous cell carcinomas of the larynx and that its coordinate overexpression with MT1-MMP and gelatinase A may have a cooperative effect in the progression of the tumours.

Collagenase 2 (MMP-8) expression in murine tissue-remodeling processes. Analysis of its potential role in postpartum involution of the uterus

Neutrophil collagenase or collagenase 2 (MMP-8) is unique among the family of matrix metalloproteinases (MMPs) because of its exclusive pattern of expression in inflammatory conditions. At present, no evidence of the occurrence of this enzyme in tissues other than human has been reported. In this work, we have cloned the murine homologue of human collagenase 2. The isolated cDNA contains an open reading frame coding for a polypeptide of 465 amino acids, which is 74% identical to its human counterpart. The mouse collagenase 2 exhibits the domain structure characteristic of several MMPs, including a signal sequence, a prodomain with the cysteine residue essential for enzyme latency, an activation locus with the Zinc-binding site, and a COOH-terminal fragment with sequence similarity to hemopexin. It also contains the three conserved residues (Tyr-209, Asp-230, and Gly-232) located around the Zinc-binding site and are distinctive of the collagenase subfamily. Northern blot analysis of RNAs isolated from a variety of mouse tissues revealed that collagenase 2 is expressed at late stages during mouse embryogenesis, coinciding with the appearance of hematopoietic cells. In addition, collagenase 2 was highly expressed in the postpartum uterus starting at 1 day postpartum and extending up to 5 days. Enzymatic analysis revealed that matrilysin, another MMP overexpressed in uterine tissue, is able to activate murine procollagenase 2. These data suggest that both enzymes could form an activation cascade resulting in the generation of the collagenolytic activity required during the process of massive connective tissue resumption occurring in the involuting uterus.

Collagenase-3 (MMP-13) expression in chondrosarcoma cells and its regulation by basic fibroblast growth factor

Human collagenase-3 (MMP-13) is a member of the matrix metalloproteinase family of enzymes that was originally identified in breast carcinomas and subsequently detected during fetal ossification and in arthritic processes. In this work, we have found that collagenase-3 is produced by HCS-2/8 human chondrosarcoma cells. An analysis of the ability of different cytokines and growth factors to induce the expression of collagenase-3 in these cells revealed that basic fibroblast growth factor (bFGF or FGF-2) strongly up-regulated the expression of this gene. By contrast, other factors, including interleukin-1beta and transforming growth factor-beta, previously found to induce collagenase-3 expression in other cell types, did not exhibit any effect on the expression of this gene in chondrosarcoma cells. Further analysis of the bFGF-induced expression of collagenase-3 in human chondrosarcoma cells revealed that its effect was time and dose dependent, but independent of the de novo synthesis of proteins. Western blot analysis revealed that the up-regulatory effect of bFGF on collagenase-3 was also reflected at the protein level as demonstrated by the increase of immunoreactive protein in the conditioned medium of HCS-2/8 cells treated with bFGF. Immunohistochemical analysis of the presence of collagenase-3 in a series of 8 benign and 16 malignant cartilage-forming neoplasms revealed that all analyzed malignant chondrosarcomas stained positively for collagenase-3, whereas only 2 of 8 benign lesions produced this protease. In addition, the finding that bFGF was detected in all analyzed chondrosarcomas, together with the above in vitro studies on HCS-2/8 cells, suggest that this growth factor may be an in vivo modulator of collagenase-3 expression in these malignant tumors. These results extend the pattern of tumor types with ability to produce this matrix metalloproteinase and suggest that collagenase-3 upregulation may contribute to the progression of human chondrosarcomas.

[Diffuse sclerosing papillary thyroid carcinoma. Report of two cases]

Unlike classical papillary carcinoma, diffuse sclerosing papillary thyroid carcinoma presents as a diffuse goiter with a discretely irregular surface, associated to hypo or hyperthyroidism, specially in young women. We report two women aged 41 and 23 years old with this disease, one with normal thyroid function and the other with hyperthyroidism. It is concluded that diffuse sclerosing papillary thyroid carcinoma must be suspected in patients with rapidly growing goiter with irregular surface or diffuse minute calcifications, specially in the presence of hypo or hyperthyroidism. Fine needle aspiration is a good diagnostic procedure.