SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Cytotoxicity-directed fractionation of an organic extract of the tunicate Lissoclinum patella afforded a new cyclic octapeptide, patellamide F [1]. The structure and absolute stereochemistry of 1 were established by a combination of spectroscopic and chemical methods. Three known cyclic peptides, patellamide B [2], ulithiacyclamide, and lissoclinamide 3, were also isolated and identified.
Four new cyclic peptides, patellamide G (2) and ulithiacyclamides E-G (3-5), along with the known patellamides A-C (6-8) and ulithiacyclamide B (9), were isolated from the ascidian Lissoclinum patella collected in Pohnpei, Federated States of Micronesia. The planar structures of these peptides were determined from 1D and 2D 1H and 13C NMR spectra. The absolute stereochemistries of the amino acid units, except for cysteine, were assigned by chiral GC analysis of N(O)-trifluoroacetyl isopropyl ester derivatives of amino acids obtained by acid hydrolysis of the intact and ozonized peptides. The structures of ulithiacyclamides E-G (3-5) were confirmed by chemical conversion. Patellamides B (7) and C (8) exhibited in vitro modulation of multidrug resistance in CEM/VBL100 cells.
1. The preparation, purification, chemical and spectral properties of potassium 4-methylumbelliferone sulphate are described. 2. The use of 4-methylumbelliferone sulphate as a substrate for the arylsulphatase of Patella vulgata is presented with specific reference to the fluorimetric assay procedure used with this substrate. 3. 4-Methylumbelliferone sulphate is compared with the previously used synthetic sulphatase substrates nitrocatechol sulphate and p-nitrophenyl sulphate with respect to K(m), V(max.) and sensitivity in the assay of arylsulphatase. 4. 4-Methylumbelliferone sulphate was strongly inhibited by phosphate. Sulphate, a less potent inhibitor, appeared to be of the competitive type with some anomalous characteristics.
1. alpha-Mannosidase from the limpet, Patella vulgata, was purified nearly 150-fold, with 40% recovery. beta-N-Acetylglucosaminidase was removed from the preparation by treatment with ethanol. The final product was virtually free from beta-galactosidase. 2. Limpet alpha-mannosidase was assayed at pH3.5 and at this pH it was necessary to add Zn(2+) for full activity. At pH5, the enzyme had the same activity in the presence or absence of added Zn(2+). 3. On incubation at acid pH, the enzyme underwent reversible inactivation, which was prevented by adding Zn(2+). 4. EDTA accelerated inactivation and the addition of Zn(2+) at once restored activity. No other cation was found to reactivate the enzyme. 5. Cl(-) had an unspecific effect on hydrolysis by limpet alpha-mannosidase. It increased the rate of reaction with substrate. The anion did not prevent or reverse inactivation by EDTA. 6. It is concluded that alpha-mannosidase is a metalloenzyme or enzyme-metal ion complex, dissociable at the pH of activity, and that it requires Zn(2+) specifically.
OBJECTIVE: To further our understanding of the pathogenesis of chondromalacia of the patella (CM), we have studied the release into knee joint fluid and serum, obtained from patients with CM, of molecules associated with the metabolism of joint cartilage matrix and synovium. METHODS: Interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), stromelysin-1 (MMP-3), interstitial collagenase (MMP-1), tissue inhibitor for metalloproteinases-1 (TIMP-1), phospholipase activity A2 (PLA2), hyaluronan (HA), aggrecan fragments (AGN) and antigenic keratan sulfate (KS) were quantified in knee joint lavage fluid from 96 patients with CM; KS and HA also was measured in serum. Chondromalacia was graded on a scale of I to IV according to Outerbridge (1961). The histopathology of the synovial membrane close to the patellofemoral joint was evaluated. Control samples were obtained from nine patients with knee pain presenting with arthroscopically normal knee joints. RESULTS: The concentrations of MMP-3, MMP-1 and TIMP-1 proteins in joint lavage fluid were increased in advanced (grade IV) CM, compared with controls. Levels of MMP-1 in lavage fluid correlated with the severity of CM (r = 0.38, P < 0.01) and MMP-1 and MMP-3 concentrations correlated with each other (r = 0.45, P < 0.001). TIMP-1 was elevated in grade IV CM compared with grades II and III CM (P < 0.02, P < 0.01). Interleukins (IL-1 alpha, IL-1 beta and IL-6) showed no significant change in CM. The lavage fluid level of PLA2 increased with the severity of CM (r = 0.40, P < 0.001). Serum KS was higher in CM IV than in controls (P = 0.05), while lavage fluid KS concentration was elevated in CM I (P = 0.04). There were no differences in the lavage fluid levels of AGN and HA between the different study groups. Synovium showed slight or moderate histological signs of inflammation in 9% of CM patients. CONCLUSION: The changes in the release and activity of these marker molecules from serum and synovial fluid may reflect changes in the metabolism of articular cartilage and synovium in CM, that are consistent with those observed in early-stage tibiofemoral cartilage changes in OA.
In the present work, both seawater and limpets (Patella vulgata L.) were collected from different sampling points in the Vigo estuary area (Galicia, NW Spain) and their heavy metal concentrations (Zn, Cd, Pb, Cu) were determined by means of a voltammetric technique. The results showed a direct relationship between the heavy metal levels in seawater and the content in biological samples, especially those obtained from limpet soft tissues, directly related to the increasing importance of anthropogenic environmental contamination. Heavy metal concentrations were usually higher in soft tissues than in shell, with a maximum difference corresponding to Cd and Zn (average of 93.6 and 86 folds, respectively). As expected, heavy metal content was higher in animal samples situated in inner part of the estuary zone, except for cadmium content in soft tissues, where a maximum of 5.62 ppm was quantified in limpet soft tissues collected next to the open sea area. Statistical analysis allowed the establishment of a clear relationship between Zn and Cd content in both shells and soft tissues from limpet, and especially between Zn and Cu in soft tissues (p < 0.001).
Methods to confirm morphine in urine require hydrolysis to liberate morphine from its 3-beta-D glucuronide (M-3G) conjugate. Lengthy enzyme hydrolysis procedures prolong testing turnaround time whereas rapid enzyme methods may produce a low conversion of M-3G to morphine. The purpose of this study was to evaluate the quantitative conversion of M-3G to morphine in human urine using a thermally stable beta-glucuronidase isolated from Patella vulgata; to compare these findings with those obtained from acid hydrolysis; and to compare between-run imprecision for both hydrolysis methods. We found both enzyme and acid hydrolysis techniques to be efficient, giving 90.4% and 92.8% conversion of M-3G to morphine, respectively. Also, both methods were found to be reproducible. Over a 14 week period, 20 opiate confirmation batches were analyzed by each hydrolysis method; the coefficient of variation for morphine liberated from M-3G was 5.5% for enzyme hydrolysis and 2.7% for acid hydrolysis.
1. From the marine mollusc, Patella granatina, a histone has been isolated. Its primary structure has been established and it has been designated histone H2Bpatella. It consists of a polypeptide chain of 121 amino acids. 2. In the carboxy-terminal two thirds of the molecule there is a highly degree of sequence homology to the corresponding region in calf histone H2B with identical residues in 95% of the positions. 3. In the N-terminal 22 amino acids histone H2Bpatella differs considerably from the mammalian histone H2B and it is shorter by four residues.
Spontaneous rupture of the triceps tendon is a rare injury, 24 cases having been previously reported in the Literature. Patella cubiti is the rare anomaly of a sesamoid bone in the triceps tendon. We report a combination of the two conditions.
A two-year-old female alpaca suddenly became lame on its right hindlimb. Eight days later clinical and radiographic examinations showed that the patella had become temporarily fixed within the supratrochlear notch of the femur. Under general anaesthesia an abrasion trochleoplasty followed by fascial imbrication was carried out. After two weeks in supporting slings, the animal put full weight on the leg, and six months after the surgery it showed no signs of lameness or recurrence of the upward fixation.
As part of a series of investigations into the conformational stability of a C2-symmetric or related cyclic peptide isolated from the ascidian Lissoclinum patella, the molecular conformation of patellamide A, the chemical structure of which deviates slightly for C2-symmetry, was determined by X-ray crystal analysis. Patellamide A took on a saddle-shaped rectangular form and wrapped around the water and methanol solvents. This conformation which is very similar to that of C2-symmetric ascidiacyclamide would be proposed as a possible candidate for biologically "active" conformation.
A case of incapacitating patella cubiti, probably of congenital origin, in a 45-year-old farm labourer is described. The fragment was extirpated, the pain disappeared and the patient returned to work.
Osteochondritis dissecans of the patella in 9 patients (6 men, 3 women; mean age 19 years) was located in the median ridge and paramedial areas and was bilateral in 3 patients. All patients were initially treated conservatively with complete relief of symptoms in 5. In 7 patients fragments were excised and the crater was curetted and drilled. At follow-up after 4 (2-8) years, the patients had no restriction of activities and they had no pain.
Posterolateral dislocations involve significant injury to the medial structures of the knee, therefore particular attention should be paid to repairing the medial patella stabilizers at the time of open reduction.
We have observed over 25 different mutations in the diastrophic dysplasia sulphate transporter gene (DTDST) in association with the recessive disorders achondrogenesis 1B, atelosteogenesis 2, and diastrophic dysplasia. The c862t (R279W) transition is the most common mutation in non-Finnish patients, but in these disorders it is usually combined with other DTDST mutations. We had not seen a case of homozygosity for c862t (R279W) until we analysed DNA from a 36 year old male with tall-normal stature (180 cm) who asked for genetic counselling for suspected multiple epiphyseal dysplasia. He was treated for club foot and hip dysplasia at birth. Skeletal changes consistent with multiple epiphyseal dysplasia, with the peculiar finding of a double layered patella, were recognised during childhood. Cleft palate, swelling of the ear pinna, and hitch hiker thumb were absent. He was found to be homozygous, and both healthy parents heterozygous, for the R279W mutation in DTDST, and his fibroblasts showed a sulphate incorporation defect typical of DTDST disorders. Counselling was given for a recessive disorder, thereby considerably reducing the probability of affected offspring. Multiple epiphyseal dysplasia is more frequently caused by dominant mutations in the COMP (EDM1, McKusick 132400) and COL9A2 genes (EDM2, McKusick 600204). A few other patients and families with features similar to our proband have been described previously and considered to have autosomal recessive MED (EDM4, McKusick 226900). This observation confirms the existence of this entity and assigns it to the phenotypic spectrum associated with mutations at the DTDST locus.
We present an interesting case of intra-articular, horizontal dislocation of an adult patella without rupture of the quadriceps muscle tendon or a patellar fracture.
Superior dislocation of the patella is a rare diagnosis, which usually occurs after a trivial trauma. It usually requires manipulation with analgesics or may even need anaesthesia. We report a case of spontaneous reduction of the dislocation, which lead us to believe that this may be more common in the community than has been reported.
Patella dislocation is a classical injury affecting teenagers. In 2/3 of cases, it occurs in sports activities. It is often a benign trauma which happens in a patello-femoral dysplasia context, leading to dislocation and reccurence if nothing is done to correct the defaults. Radiographic and scanner examinations allow to measure the dysplasia parameters and think about its correction. With MRI documentation, capsulo-ligamentous and cartilaginous lesions can be identified and their surgical repair can be discussed. When the dislocation occurs in a normal anatomical context, conservative therapy is still indicated.