Open repair of massive rotator cuff tears in patients aged sixty-five years or over: is it worthwhile?

The purpose of the study was to evaluate the functional outcome and identify possible preoperative prognostic factors in patients aged 65 years or over undergoing open repair for a massive (>5 cm) full-thickness rotator cuff tear. Patients were assessed after a mean of 48 months by an independent observer by use of the Constant score and the Oxford Shoulder Questionnaire. The outcome was excellent or good in 44% and poor in 23%. The patient satisfaction rate was 84%. Pain relief was obtained in 93%. We found three preoperative variables to be significantly associated with a poor outcome: female sex, duration of symptoms greater than 34 months before surgery, and American Society of Anesthesiologists grade. The results of our study suggest that appropriately selected patients who are aged 65 years or over with a massive full-thickness rotator cuff tear can be expected to have a good functional outcome and pain relief after repair.

Delayed fracture of the ceramic femoral head after trauma.

There are various ways in which a total hip arthroplasty may fail catastrophically. Failure of the ceramic femoral head component is well known and described. It may fail because of trauma, but delayed fracture after trauma has not been described previously. This case report describes this phenomenon and postulates a possible mechanism for this failure.

TGFbeta and PTHrP control chondrocyte proliferation by activating cyclin D1 expression.

Exact coordination of growth plate chondrocyte proliferation is necessary for normal endochondral bone development and growth. Here we show that PTHrP and TGFbeta control chondrocyte cell cycle progression and proliferation by stimulating signaling pathways that activate transcription from the cyclin D1 promoter. The TGFbeta pathway activates the transcription factor ATF-2, whereas PTHrP uses the related transcription factor CREB, to stimulate cyclin D1 promoter activity via the CRE promoter element. Inhibition of cyclin D1 expression with antisense oligonucleotides causes a delay in progression of chondrocytes through the G1 phase of the cell cycle, reduced E2F activity, and decreased proliferation. Growth plates from cyclin D1-deficient mice display a smaller zone of proliferating chondrocytes, confirming the requirement for cyclin D1 in chondrocyte proliferation in vivo. These data identify the cyclin D1 gene as an essential component of chondrocyte proliferation as well as a fundamental target gene of TGFbeta and PTHrP during skeletal growth.

Isolation of a cytokinin gene, ZOG1, encoding zeatin O-glucosyltransferase from Phaseolus lunatus.

Zeatin is the most active and ubiquitous of the naturally occurring cytokinins. The O-glucoside of zeatin, found in all plants examined, is considered to be important in cytokinin transport, storage, and protection against cytokinin oxidases. The enzyme UDPglucose:zeatin O-glucosyltransferase (EC 2.4.1.203) was previously isolated from Phaseolus lunatus seeds. Immunoscreening of an expression library with monospecific antibody resulted in the isolation of a cDNA encoding the enzyme. The recombinant protein efficiently converts labeled zeatin to O-glucosylzeatin and has properties similar to the native enzyme. The cDNA of 1.5 kb contains an ORF encoding a 51. 4-kDa polypeptide of 459 amino acids. The sequence is unique based on a BLAST search of data bases. The genomic sequence, isolated with PCR using specific primers based on the cDNA sequence, does not contain introns. The cloning of this gene provides the tools for further study of the regulation of cytokinin metabolism and analysis of the precise role of O-glucosylzeatin in plant development.

Expression of the yeast FRE genes in transgenic tobacco.

Two yeast genes, FRE1 and FRE2 (encoding Fe(III) reductases) were placed under the control of the cauliflower mosaic virus 35S promoter and introduced into tobacco (Nicotiana tabacum L.) via Agrobacterium tumefaciens-mediated transformation. Homozygous lines containing FRE1, FRE2, or FRE1 plus FRE2 were generated. Northern-blot analyses revealed mRNA of two different sizes in FRE1 lines, whereas all FRE2 lines had mRNA only of the expected length. Fe(III) reduction, chlorophyll contents, and Fe levels were determined in transgenic and control plants under Fe-sufficient and Fe-deficient conditions. In a normal growth environment, the highest root Fe(III) reduction, 4-fold higher than in controls, occurred in the double transformant (FRE1 + FRE2). Elevated Fe(III) reduction was also observed in all FRE2 and some FRE1 lines. The increased Fe(III) reduction occurred along the entire length of the roots and on shoot sections. FRE2 and double transformants were more tolerant to Fe deficiency in hydroponic culture, as shown by higher chlorophyll and Fe concentrations in younger leaves, whereas FRE1 transformants did not differ from the controls. Overall, the beneficial effects of FRE2 were consistent, suggesting that FRE2 may be used to improve Fe efficiency in crop plants.

Protein processing and auxin response in transgenic tobacco harboring a putative cDNA of zeatin O-xylosyltransferase from Phaseolus vulgaris.

Zeatin is rapidly metabolized to O-xylosylzeatin in Phaseolus vulgaris seeds. The zeatin O-xylosyltransferase mediating this conversion, a 50 kDa protein, occurs mainly in the endosperm, both in the cytoplasm and the nuclei. A monoclonal antibody specific to the enzyme was used to isolate cDNAs from an expression library derived from P. vulgaris seeds. Two highly homologous, full-length cDNAs were isolated. The ORFs encode proteins of 69 and 67 kDa, respectively, with 90% homology at the amino acid level. cDNA-encoded protein obtained from in vitro transcription/translation was processed to protein of 50 kDa by bean endosperm extract. Transgenic tobacco plants harboring the larger ORF under the control of the CaMV35S promoter were more sensitive to the auxin NAA than control plants. The symptoms included leaf chlorosis, restriction of root elongation, and eventual cessation of growth. The antigenic preprotein was processed, and labeled zeatin was converted to O-xylosylzeatin in transgenic plants grown on NAA-containing medium. Analyses of independently transformed families indicated that the presence of the transgene coincided with the increased auxin sensitivity and protein processing correlated with the manifestation of auxin-induced damage. These results suggest that posttranslational processing regulates enzyme activity, and offer the possibility that cytokinin-auxin balance may be affected by stimulation of cytokinin metabolic enzyme activity by auxin.

A temperature-dependent morphological mutant of tobacco.

A recessive temperature dependent shooty mutant (tds) of Nicotiana tabacum L. (W38) is described. The mutant phenotype is expressed at low temperature (21 degrees C). Mutant characteristics include thick, narrow leaves with abnormal mesophyll cells, short internodes, and near absence of apical dominance. Most plants remain vegetative and the occasional flower has petaloid stamens. High temperature (30 degrees C) reverses the mutant phenotype, with formation of normal leaves and restoration of apical dominance. However, many flowers still have petaloid stamens. Reciprocal grafting and auxincytokinin interaction experiments do not suggest shifts in auxin-cytokinin balance. Overall, this mutant bears some resemblance to transgenic tobacco overexpressing homeodomain genes from maize and Arabidopsis.

A monoclonal antibody specific to zeatin o-glycosyltransferases of phaseolus.

Zeatin O-xylosyltransferase and zeatin O-glucosyltransferase occur in immature embryos of Phaseolus vulgaris and P. lunatus, respectively. Purified preparations of the xylosyltransferase were used as antigen to elicit the formation of antibodies in mice. Hybridoma clones were produced by fusion of mouse spleen cells with myeloma cell line Fox-NY. A clone secreting monoclonal antibody (MAb), XZT-1, capable of immunoprecipitating both enzymes was obtained. The MAb detected a unique protein band from crude embryo extracts of each species with the correct molecular mass (50 kilodaltons) and relative charge (R(F) = 0.5 and 0.3) of the respective enzymes. Competition experiments with substrates indicated that the glycosyl dinucleotide binding sites of the enzymes are probably not involved in MAb-enzyme recognition. Western blotting of samples from vegetative tissues of P. vulgaris detected a low level of O-glucosyltransferase but not O-xylosyltransferase, in leaves. These findings suggest the occurrence of two genes in P. vulgaris coding for O-glycosylation enzymes with tissue-specific expression. The MAb will be used to screen expression libraries and to obtain pure enzymes for amino acid sequencing and for the production of additional MAbs.

The diagnostic value of arthroscopy in glenohumeral instability.

Over a six-year period, 166 shoulder arthroscopies were performed in 153 patients with symptoms of subluxation, but no firm evidence of dislocation and no clear-cut clinical diagnosis. Arthroscopy confirmed the working diagnosis in 133 shoulders (80%), but changed it in 33 (20%). In 26 shoulders the presumed direction of instability was changed and in seven a different diagnosis was made. Arthroscopy was particularly helpful for patients with shoulder instability of uncertain type or direction.

An enzyme mediating the conversion of zeatin to dihydrozeatin in phaseolus embryos.

A reductase catalyzing the conversion of zeatin to dihydrozeatin was detected in soluble fractions of immature Phaseolus vulgaris embryos. The enzyme was partially purified by ammonium sulfate fractionation and affinity, gel filtration, and anion exchange chromatography. NADPH was the only cofactor required for enzyme activity, and the pH optimum was 7.5 to 8.0. The enzyme did not recognize compounds closely related to zeatin, such as ribosylzeatin, cls-zeatin, O-xylosylzeatin, N(6)-(Delta(2)-isopentenyl)adenine, or N(6)-(Delta(2)-isopentenyl)adenosine. No conversion of dihydrozeatin to zeatin by the enzyme was observed. Two forms of the reductase could be separated by either gel filtration or anion exchange high performance liquid chromatography. The high molecular weight isozyme (M(r) 55,000 +/- 5,000) eluted as the second peak from the anion exchange column, while the low molecular weight isozyme (M(r) 25,000+/- 5000) was less negatively charged. The results suggest that side chain reduction occurs at the free base level. In addition, Phaseolus embryos are useful for the detection of zeatin-specific metabolic enzymes.

Ring uncemented plastic on metal hip replacements--results from an independent unit.

We present 251 Ring uncemented plastic on metal (UPM) hip replacements with a follow-up of 2-5 years. Judging the functional results by the Harris hip evaluation for the surviving 234 hips, 79.8% were good to excellent, 11.7% fair, and 8.5% poor at an average of 3 years. The mortality within one month of surgery was 0.79%. There were 4 cases of deep infection (1.59%), 3 of which required excision arthroplasty. At 3 years, 6 hips (2.39%) had required revision, all for aseptic femoral loosening, 2 of which also had acetabular loosening. Ring UPM hip is both safe and reliable in the hands of many surgeons outside Ring's unit.

Decreased biliary excretion of piperacillin after percutaneous relief of extrahepatic obstructive jaundice.

The biliary excretion of piperacillin has been assessed in 11 patients with obstructive jaundice due to hilar cholangiocarcinoma. After a 1-g intravenous dose administered 30 min before preliminary percutaneous transhepatic cholangiography, no drug was detected in the bile of seven patients; in four others, drug concentrations were far below the corresponding level in serum. After a period of external biliary drainage of up to 28 days, levels of antibiotic in bile after intravenous administration were only minimally increased. The results suggest that although the impairment of hepatic function may be improved by external biliary decompression when assessed by a fall in plasma bilirubin, the biliary elimination of piperacillin and related beta-lactam antibiotics may remain impaired for prolonged periods.

Zeatin Metabolism in Fruits of Phaseolus: Comparison between Embryos, Seedcoat, and Pod Tissues.

Zeatin metabolites were isolated from seedcoats and pod tissues of Phaseolus vulgaris and P. lunatus. The differences observed previously between P. vulgaris and P. lunatus embryos, i.e. the formation of O-ribosyl derivatives in the former and O-glucosyl derivatives in the latter, could also be detected in seedcoats, although the levels of these metabolites were much lower and there was a concomitant increase of breakdown products (adenine, adenosine and AMP). Inner pod wall tissues of both genotypes metabolized zeatin at a slow rate and the major metabolite was the mononucleotide of zeatin. The array of metabolites recovered was not influenced by the extraction method (cold ethanol or modified Bieleski solution).

Erythema ab igne in chronic pancreatic pain: a diagnostic sign.

Two patients with severe chronic pain of pancreatic origin are described. In both there was severe back pain and an area of erythema ab igne lay directly over the portion of the pancreas giving rise to the pain. In both patients therapy directed at these areas of diseased pancreas resulted in relief of symptoms. The presence of erythema ab igne on a patient's back at the level of T12-L2 should arouse suspicion of underlying pancreatic pathology, and this may be valuable in a disease with remarkably little to find on clinical examination. In one patient early obstruction of the pancreatic duct by pancreatic carcinoma caused distal chronic pancreatitis and back pain many months before the onset of obstructive jaundice.

Effects of Thidiazuron on Cytokinin Autonomy and the Metabolism of N-(Delta-Isopentenyl)[8-C]Adenosine in Callus Tissues of Phaseolus lunatus L.

The effects of a highly cytokinin-active urea derivative, N-phenyl-N'-1,2,3-thiadiazol-5-ylurea (Thidiazuron), and zeatin on cytokinin-autonomous growth and the metabolism of N(6)-(Delta(2)-isopentenyl)[8-(14)C]adenosine ([(14)C]i(6) Ado) were examined in callus tissues of two Phaseolus lunatus genotypes, cv Jackson Wonder and P.I. 260415. Tissues of cv Jackson Wonder maintained on any concentration of Thidiazuron became cytokinin autonomous, whereas only tissues exposed to suboptimal concentrations of zeatin displayed cytokinin-autonomous growth. Tissues of P.I. 260415 remained cytokinin dependent under all these conditions. The metabolism of [(14)C]i(6) Ado was similar for the two genotypes, but differed with the medium used. [(14)C]i(6) Ado was rapidly converted to N(6)-(Delta(2)-isopentenyl)[8-(14)C]adenosine 5'-P ([(14)C]i(6) AMP) by tissues grown on zeatin-containing medium, whereas only traces of the nucleotide were formed in tissues grown on medium with Thidiazuron. Incubation with [(14)C] i(6) AMP of tissues grown in the presence of Thidiazuron resulted in rapid conversion to [(14)C]i(6) Ado, while [(14)C]i(6) AMP persisted in tissues maintained on zeatin. Thus, Thidiazuron appears to stimulate enzyme activity converting the ribonucleotide to ribonucleoside. Although the cytokininactive phenylureas and adenine derivatives differ in their effects on cytokinin autonomy as well as nucleotide formation, the two types of effects do not seem to be related.

Cytokinin structure-activity relationships and the metabolism of N-(delta-isopentenyl)adenosine-8-C in phaseolus callus tissues.

The activities of the free base and ribonucleoside forms of cytokinins bearing saturated and unsaturated N(6)-isoprenoid side chains have been examined in callus cultures derived from Phaseolus vulgaris cv. Great Northern, P. lunatus cv. Kingston, and the interspecific hybrid Great Northern x Kingston. In callus of cv. Great Northern, cytokinins bearing saturated side chains (N(6)-isopentyladenine, N(6)-isopentyladenosine, dihydrozeatin, and ribosyldihydrozeatin) were always more active than the corresponding unsaturated analogs (N(6)-[Delta(2)-isopentenyl]adenine, N(6)-[Delta(2)-isopentenyl]adenosine, zeatin, and ribosylzeatin). In callus of cv. Kinston, the cytokinins bearing unsaturated side chains were either more active or equally as active as the saturated compounds. These differences in cytokinin structure-activity relationships were correlated with differences in the metabolism of (14)C-N(6)-(Delta(2)-isopentenyl)adenosine. In Great Northern tissues, this cytokinin was rapidly degraded to adenosine; in Kingston tissues, the major metabolite was the corresponding nucleotide. The growth responses of callus of the interspecific hybrid were intermediate between the parental tissues, and the metabolism of (14)C-N(6)-(Delta(2)-isopentenyl)adenosine by the hybrid callus exhibited characteristics of both parental tissues. The results are consistent with the hypothesis that the weak activity of cytokinins with unsaturated side chains in promoting the growth of Great Northern callus is due to the rapid conversion of these cytokinins to inactive metabolites.