Age and synovitis affect the results of the treatment of knee osteoarthritis with Microfragmented Autologous Fat Tissue

PURPOSE

This study aims to assess the effectiveness of Microfragmented Autologous Fat Tissue (MFAT) treatment for knee osteoarthritis and to investigate whether patients' pre-treatment clinical condition, such as synovitis, correlates with clinical outcomes, to identify potential predicting factors for the success or failure of the treatment.

METHODS

In this prospective Cohort Study Level II multicentric trial, consecutive patients with a diagnosis of early/mild osteoarthritis and failure of previous conservative measures were enrolled to undergo diagnostic arthroscopy and a single MFAT injection. Patients were assessed with repeated scoring systems at baseline, 6 months, and 12 months after surgery. The demographic features, the arthroscopic findings, the immunophenotype of injected tissue and the histologic examination of synovia of failed patients were analyzed.

RESULTS

Data from 91 patients showed a significant improvement in Lysholm, WOMAC scores at 1-year follow-up (p < 0.001). A significant decrease in VAS score was observed, while a significant improvement of measured flexion angle was registered at 1 year (p < 0.001). No major complications were reported. Age and synovitis were identified as significant factors influencing the clinical outcome (p < 0.05). Body mass index, previous or concomitant procedures, and specific cartilage defects had no influence. The mean number of injected adipose tissue-derived mesenchymal stem cells seem not to correlate with the clinical outcome.

CONCLUSION

MFAT is effective in reducing pain when used with a single dose injection in early/mild OA of the knee, without major complications. Age over 60 and synovitis may be predictive for persistent pain at one year and should be considered before indications.

Determination of Epidemiological Cutoff Values for Antimicrobial Resistance of Enterococcus cecorum

Enterococcus cecorum, a commensal Gram-positive bacterium of the chicken gut, has emerged as a worldwide cause of lameness in poultry, particularly in fast-growing broilers. It is responsible for osteomyelitis, spondylitis, and femoral head necrosis, causing animal suffering, mortality, and antimicrobial use. Research on the antimicrobial resistance of E. cecorum clinical isolates in France is scarce, and epidemiological cutoff (ECOFF) values are unknown. To determine tentative ECOFF (COWT) values for E. cecorum and to investigate the antimicrobial resistance patterns of isolates from mainly French broilers, we tested the susceptibility of a collection of commensal and clinical isolates (n = 208) to 29 antimicrobials by the disc diffusion (DD) method. We also determined the MICs of 23 antimicrobials by the broth microdilution method. To detect chromosomal mutations conferring antimicrobial resistance, we investigated the genomes of 118 E. cecorum isolates obtained mainly from infectious sites and described previously in the literature. We determined the COWT values for more than 20 antimicrobials and identified two chromosomal mutations explaining fluoroquinolone resistance. The DD method appears better suited for detecting E. cecorum antimicrobial resistance. Although tetracycline and erythromycin resistances were persistent in clinical and nonclinical isolates, we found little or no resistance to medically important antimicrobials.

Regulation of Cell Wall Plasticity by Nucleotide Metabolism in Lactococcus lactis

To ensure optimal cell growth and separation and to adapt to environmental parameters, bacteria have to maintain a balance between cell wall (CW) rigidity and flexibility. This can be achieved by a concerted action of peptidoglycan (PG) hydrolases and PG-synthesizing/modifying enzymes. In a search for new regulatory mechanisms responsible for the maintenance of this equilibrium in Lactococcus lactis, we isolated mutants that are resistant to the PG hydrolase lysozyme. We found that 14% of the causative mutations were mapped in the guaA gene, the product of which is involved in purine metabolism. Genetic and transcriptional analyses combined with PG structure determination of the guaA mutant enabled us to reveal the pivotal role of the pyrB gene in the regulation of CW rigidity. Our results indicate that conversion of l-aspartate (l-Asp) to N-carbamoyl-l-aspartate by PyrB may reduce the amount of l-Asp available for PG synthesis and thus cause the appearance of Asp/Asn-less stem peptides in PG. Such stem peptides do not form PG cross-bridges, resulting in a decrease in PG cross-linking and, consequently, reduced PG thickness and rigidity. We hypothesize that the concurrent utilization of l-Asp for pyrimidine and PG synthesis may be part of the regulatory scheme, ensuring CW flexibility during exponential growth and rigidity in stationary phase. The fact that l-Asp availability is dependent on nucleotide metabolism, which is tightly regulated in accordance with the growth rate, provides L. lactis cells the means to ensure optimal CW plasticity without the need to control the expression of PG synthesis genes.

Surface proteome analysis of a natural isolate of Lactococcus lactis reveals the presence of pili able to bind human intestinal epithelial cells

Surface proteins of Gram-positive bacteria play crucial roles in bacterial adhesion to host tissues. Regarding commensal or probiotic bacteria, adhesion to intestinal mucosa may promote their persistence in the gastro-intestinal tract and their beneficial effects to the host. In this study, seven Lactococcus lactis strains exhibiting variable surface physico-chemical properties were compared for their adhesion to Caco-2 intestinal epithelial cells. In this test, only one vegetal isolate TIL448 expressed a high-adhesion phenotype. A nonadhesive derivative was obtained by plasmid curing from TIL448, indicating that the adhesion determinants were plasmid-encoded. Surface-exposed proteins in TIL448 were analyzed by a proteomic approach consisting in shaving of the bacterial surface with trypsin and analysis of the released peptides by LC-MS/MS. As the TIL448 complete genome sequence was not available, the tryptic peptides were identified by a mass matching approach against a database including all Lactococcus protein sequences and the sequences deduced from partial DNA sequences of the TIL448 plasmids. Two surface proteins, encoded by plasmids in TIL448, were identified as candidate adhesins, the first one displaying pilin characteristics and the second one containing two mucus-binding domains. Inactivation of the pilin gene abolished adhesion to Caco-2 cells whereas inactivation of the mucus-binding protein gene had no effect on adhesion. The pilin gene is located inside a cluster of four genes encoding two other pilin-like proteins and one class-C sortase. Synthesis of pili was confirmed by immunoblotting detection of high molecular weight forms of pilins associated to the cell wall as well as by electron and atomic force microscopy observations. As a conclusion, surface proteome analysis allowed us to detect pilins at the surface of L. lactis TIL448. Moreover we showed that pili appendages are formed and involved in adhesion to Caco-2 intestinal epithelial cells.

Cell surface of Lactococcus lactis is covered by a protective polysaccharide pellicle

In Gram-positive bacteria, the functional role of surface polysaccharides (PS) that are not of capsular nature remains poorly understood. Here, we report the presence of a novel cell wall PS pellicle on the surface of Lactococcus lactis. Spontaneous PS-negative mutants were selected using semi-liquid growth conditions, and all mutations were mapped in a single chromosomal locus coding for PS biosynthesis. PS molecules were shown to be composed of hexasaccharide phosphate repeating units that are distinct from other bacterial PS. Using complementary atomic force and transmission electron microscopy techniques, we showed that the PS layer forms an outer pellicle surrounding the cell. Notably, we found that this cell wall layer confers a protective barrier against host phagocytosis by murine macrophages. Altogether, our results suggest that the PS pellicle could represent a new cell envelope structural component of Gram-positive bacteria.

Collagen binding is a key factor for the hemorrhagic activity of snake venom metalloproteinases

Snake venom metalloproteinases (SVMPs) are multifunctional enzymes involved in several symptoms following snakebite, such as severe local hemorrhage. Multidomain P-III SVMPs are strongly hemorrhagic, whereas single domain P-I SVMPs are not. This indicates that disintegrin-like and cysteine-rich domains allocate motifs that enable catalytic degradation of ECM components leading to disruption of capillary vessels. Interestingly, some P-III SVMPs are completely devoid of hemorrhagic activity despite their highly conserved disintegrin-like and cysteine-rich domains. This observation was approached in the present study by comparing the effects of jararhagin, a hemorrhagic P-III SVMP, and berythractivase, a pro-coagulant and non-hemorrhagic P-III SVMP. Both toxins inhibited collagen-induced platelet aggregation, but only jararhagin was able to bind to collagen I with high affinity. The monoclonal antibody MAJar 3, that neutralizes the hemorrhagic effect of Bothrops venoms and jararhagin binding to collagen, did not react with berythractivase. The three-dimensional structures of jararhagin and berythractivase were compared to explain the differential binding to collagen and MAJar 3. Thereby, we pinpointed a motif within the Da disintegrin subdomain located opposite to the catalytic domain. Jararhagin binds to both collagen I and IV in a triple helix-dependent manner and inhibited in vitro fibrillogenesis. The jararhagin-collagen complex retained the catalytic activity of the toxin as observed by hydrolysis of fibrin. Thus, we suggest that binding of hemorrhagic SVMPs to collagens I and IV occurs through a motif located in the Da subdomain. This allows accumulation of toxin molecules at the site of injection, close to capillary vessels, where their catalytic activity leads to a local hemorrhage. Toxins devoid of this motif would be more available for vascular internalization leading to systemic pro-coagulant effects. This reveals a novel function of the disintegrin domain in hemorrhage formation.

SpxB Regulates O-Acetylation-dependent Resistance of Lactococcus lactis Peptidoglycan to Hydrolysis

Endogenous peptidoglycan (PG)-hydrolyzing enzymes, the autolysins, are needed to relax the rigid PG sacculus to allow bacterial cell growth and separation. PGs of pathogens and commensal bacteria may also be degraded by hydrolases of animal origin (lysozymes), which act as antimicrobials. The genetic mechanisms regulating PG resistance to hydrolytic degradation were dissected in the Gram-positive bacterium Lactococcus lactis. We found that the ability of L. lactis to counteract PG hydrolysis depends on the degree of acetylation. Overexpression of PG O-acetylase (encoded by oatA) led to bacterial growth arrest, indicating the potential lethality of oatA and a need for its tight regulation. A novel regulatory factor, SpxB (previously denoted as YneH), exerted a positive effect on oatA expression. Our results indicate that SpxB binding to RNA polymerase constitutes a previously missing link in the multistep response to cell envelope stress, provoked by PG hydrolysis with lysozyme. We suggest that the two-component system CesSR responds to this stress by inducing SpxB, thus favoring its interactions with RNA polymerase. Induction of PG O-acetylation by this cascade renders it resistant to hydrolysis.

Studying the Cu binding sites in the PrP N-terminal region: a test case for ab initio simulations

First principle ab initio molecular dynamics simulations of the Car-Parrinello type have proved to be of invaluable help in understanding the microscopic mechanisms of chemical bonding both in solid state physics and in structural biophysics. In this work we present as a test case a study of the Cu coordination mode at the Prion Protein binding sites localized in the N-terminal octarepeat region. Using medium size PC-clusters, we are able to deal with systems with up to about 350 atoms and 10(3) electrons for as long as approximately 2 ps. With a foreseeable forthcoming scaling up of the available CPU times by a factor 10(3), one can hope to be soon able to simulate systems of biological interest of realistic size and for physical times of the order of the nanosecond.

Identification of candidate target antigens for antibody-based immunotherapy in childhood B-cell precursor ALL

BACKGROUND

Contemporary risk adapted treatment protocols for childhood acute lymphoblastic leukemia (ALL) rely on accurate risk assessment strategies for disease re-occurrence by incorporating clinical parameters as well as immunological, molecular and cytogenetic features of the blasts at initial manifestation. Additional risk stratification is provided by analysis of the IN VITRO and IN VIVO response of the blasts towards standard chemotherapy. Despite adapted therapies, a number of children with good and bad prognostic factors still fail therapy. One approach to this problem might be to incorporate monoclonal antibodies (MoAbs) as additional modalities into the first or second line treatment.

PATIENTS AND METHODS

In order to identify target antigen structures, we analyzed the immunological expression profiles of blasts from 181 patients with B-cell precursor ALL treated at our institution in 11 years according to the CoALL-92/97/03 protocols. Blasts were classified according to the EGIL guidelines as 9 proB-, 110 common (c-) and 62 preB-ALL.

RESULTS

> 99 and 96 % of patients expressed CD19 and CD22 on > 90 % of their blasts, respectively. HLA-DR on > 95 % blasts was present in all patients. CD10 was expressed on all c-/preB-ALL and absent on proB-ALL cells. CD20 was expressed on 11-37 % of B-cell precursor ALL samples. CD34 positive blasts were found in 89, 83 and 68 % of patients with proB-, c- and preB-ALL, respectively. CD37 expression was detected in 0-18 % of patients. < 20 % CD45(+) blasts were found in 11, 19 and 18 % of patients with proB-, c- and preB-ALL. CD33(+) was expressed on 33, 29 and 21 % of patients samples with proB-, c- and preB-ALL. Other myeloid antigens (CD13, CD14, CD15, CD65) were positive on blasts in < 25 % of patients. Analyses of the immunological profile of blasts in 9 consecutive children with relapse revealed that the antigen expression profile varied little compared to the initial diagnosis for CD10, CD19, CD22 and HLA-DR.

CONCLUSIONS

These analyses clearly identified the three antigens CD19, CD22 and HLA-DR present on blasts in more than 90 % of patients as potential target structures for targeted therapies with native or toxin-bound monoclonal antibodies in childhood ALL.

Identification of an essential gene responsible for d-Asp incorporation in the Lactococcus lactis peptidoglycan crossbridge

Bacteria such as Lactococcus lactis have D-aspartate (D-Asp) or its amidated derivative D-asparagine (D-Asn), in their peptidoglycan (PG) interpeptide crossbridge. We performed a subtractive genome analysis to identify L. lactis gene yxbA, orthologues of which being present only in bacteria containing D-amino acids in their PG crossbridge, but absent from those that instead insert L-amino acids or glycine. Inactivation of yxbA required a complementing Streptococcus pneumoniae murMN genes, which express enzymes that incorporate L-Ser-L-Ala or L-Ala-L-Ala in the PG crossbridge. Our results show that (i) yxbA encodes D-Asp ligase responsible for incorporation of D-Asp in the PG crossbridge, and we therefore renamed it as aslA, (ii) it is an essential gene, which makes its product a potential target for specific antimicrobials, (iii) the absence of D-Asp may be complemented by L-Ser-L-Ala or L-Ala-L-Ala in the L. lactis PG, indicating that the PG synthesis machinery is not selective for the side-chain residues, and (iv) lactococcal strains having L-amino acids in their PG crossbridge display defects in cell wall integrity, but are able to efficiently anchor cell wall proteins, indicating relative flexibility of lactococcal transpeptidation reactions with respect to changes in PG sidechain composition.

C-terminal WxL domain mediates cell wall binding in Enterococcus faecalis and other gram-positive bacteria

Analysis of the genome sequence of Enterococcus faecalis clinical isolate V583 revealed novel genes encoding surface proteins. Twenty-seven of these proteins, annotated as having unknown functions, possess a putative N-terminal signal peptide and a conserved C-terminal region characterized by a novel conserved domain designated WxL. Proteins having similar characteristics were also detected in other low-G+C-content gram-positive bacteria. We hypothesized that the WxL region might be a determinant of bacterial cell location. This hypothesis was tested by generating protein fusions between the C-terminal regions of two WxL proteins in E. faecalis and a nuclease reporter protein. We demonstrated that the C-terminal regions of both proteins conferred a cell surface localization to the reporter fusions in E. faecalis. This localization was eliminated by introducing specific deletions into the domains. Interestingly, exogenously added protein fusions displayed binding to whole cells of various gram-positive bacteria. We also showed that the peptidoglycan was a binding ligand for WxL domain attachment to the cell surface and that neither proteins nor carbohydrates were necessary for binding. Based on our findings, we propose that the WxL region is a novel cell wall binding domain in E. faecalis and other gram-positive bacteria.

Decreased expression of DMPK: correlation with CTG repeat expansion and fibre type composition in myotonic dystrophy type 1

Myotonic dystrophy type 1 (DM1) is an autosomal dominant disease caused by a trinucleotide repeat-expansion, cytosine-thymine-guanine (CTG)n, in the 3' untranslated region of a gene encoding the myotonic dystrophy protein kinase (DMPK). To correlate CTG expansion and protein expression, we studied muscle specimens from 16 adult DM1 patients using three anti-DMPK antibodies for immunoblotting. We estimated the amount of the full-length DMPK (85 kDa) in muscle biopsies from normal controls and from DM1 patients carrying different (CTG)n expansions. We found that DMPK concentration was decreased to about 50% in DM patients' muscles; the protein decrease did not seem correlated with the CTG repeat length. However, the fibre type composition in skeletal muscle seemed somehow to affect DMPK decrease, as the lowest level of the enzyme was found in patients with the lowest content of type 1 fibre.

Thermal regulation and intraoperative hypothermia

Thermal disturbances are very common perioperatively, especially if paediatric patients are involved. This article consider some aspects of hypothermia during and after surgery under anaesthesia in paediatric patients and how to prevent such disturbances.

Comparison of the thickening properties of four Lactobacillus delbrueckii subsp. bulgaricus strains and physicochemical characterization of their exopolysaccharides

It is now well established that physicochemical properties of exopolysaccharides (EPS) can vary between strains of a given species and according to growth conditions. The EPS production of four strains of Lactobacillus bulgaricus was monitored during growth in milk and in a chemically defined media. All strains, including the non-ropy one, produced EPS. The monosaccharide composition, molar mass (M(w)), and intrinsic viscosity of these EPS were determined and compared. Further characterization using high-performance size-exclusion chromatography revealed the presence of two fractions in all EPS: one fraction exhibited a high M(w) and a high intrinsic viscosity while the other had a low M(w) and a low intrinsic viscosity. Strikingly, the EPS synthesized by the non-ropy strain was mainly composed of the low-M(w) fraction while for the ropy strains, the fraction of high M(w) varied between 43 and 90%. According to our results, we propose that the ratio between the high-M(w) and low-M(w) fractions is critical for the texturing properties of L. bulgaricus EPS.

[Recovery Room. One-year experience]

BACKGROUND

The objective of our study is to present the analysis of the organizational and clinical work carried out in the first year of activity of the Recovery Room (RR) at the Azienda Ospedaliera Santa Maria degli Angeli of Pordenone and to compare personal experience with what is stated in the literature.

METHODS

The RR is located at the center of the operating block (composed of 10 operating rooms), the number of bed is 6, 3 of which are equipped with ventilators. There is a central nursing station where it is possible to concentrate all data deriving from the single monitors on one single screen. The RR operates from Monday to Friday from 8.00 to 20.00. An Anesthetist is on duty for the 12 hours and has the clinical, therapeutic and decision-making responsibility regarding the discharge of patients, while nursing assistance is provided by 2 qualified professional nurses for shift, assisted by an auxiliary. In the first year of activity of the RR, a total of 11,626 surgical operations were carried out; of these 1,047 patients, equal to 9%, were assisted in the RR. The age of 51% of the patients was between 61 and 80 years; 53.3% belonged to the ASA 2 group and only 0.48% to the ASA 4 group. The operations were sub-divided as follows: 56.8% general, thoracic and vascular surgery, 15.3% urological, 10% orthopedic, 7.7% obstetrical and gynecological, 6.1% ENS, 3% stomatological, 1% others. 56.8% off the patients underwent general anesthesia, 30.5% combined anesthesia and 12.6% local-regional anesthesia. The time spent by the patients in RR was between 1 hour 30 minutes and 10 hours 45 minutes, with an average time of 3 hours 49 minutes.

RESULTS

Of the 1,047 patients studied no case of cardio-respiratory arrest or death was recorded, while the complications encountered were: 13.15% cardio-circulatory, 3.62% respiratory, 3.62% PONV, 2.1% oliguria, 1.24% hypothermia, 0.48% disoriented patients, 0.38% hyperthermia and 0.38% shivering. In the area of cardio-circulatory complications encountered, the most important was arterial hypertension (5.6%), followed by cardiac arrhythmia, such as bradycardia (2.5%) and tachycardia (2.6%).

CONCLUSIONS

The conclusion is drawn that correct administration in the early postoperative period is decisive for the final outcome of surgery and that the presence of RR contributes significantly to a reduction in the postoperative morbidity rate. Our case-series leads us, however, to reflect on an excellent organization of the opening hours of RR.

Open-label phase II trial of amprenavir, abacavir, and fixed-dose zidovudine/lamivudine in newly and chronically HIV-1--infected patients

A Phase II clinical trial was designed to evaluate the efficacy and tolerability of twice-daily abacavir, amprenavir, and zidovudine (ZDV)/lamivudine (3TC) in HIV-1-infected study subjects naive to protease inhibitors and 3TC. Plasma and cerebrospinal fluid (CSF) HIV-1 RNA levels and T-cell subsets were measured. In all, 27 newly diagnosed and 12 chronically HIV-1-infected study subjects are included in the analysis. Week 48 plasma HIV-1 RNA levels were <500 copies/ml in 100% of study subjects, and <50 copies/ml in 80% of chronically infected and 100% of newly infected study subjects. The mean change in CD4 was (+)150 cells/microl (newly infected, p <.001), and (+)155 cells/microl (chronically infected, p <.001). At Week 48, evidence of cellular activation persisted in both cohorts. A twice-daily regimen of amprenavir, abacavir, and ZDV/3TC affords potent viral suppression and significant increases in total CD4(+) cells in HIV-1--infected study subjects. Patient intolerance may limit the efficacy of this combination.

Site-directed mutagenesis and deletion of three phosphorylation sites of calsequestrin of skeletal muscle sarcoplasmic reticulum. Effects on intracellular targeting

Calsequestrin (CS) is segregated to the junctional sarcoplasmic reticulum (jSR) of skeletal muscle fibers and is responsible for intraluminal Ca(2+) binding. A chimeric CS-HA1, obtained by adding the nine-amino-acid viral epitope hemagglutinin (HA1) to the carboxy-terminal of CS and shown to be correctly segregated to skeletal muscle jSR in vivo (A. Nori, K. A. Nadalini, A. Martini, R. Rizzuto, A. Villa, and P. Volpe, 1997, Am. J. Physiol. 272, C1420-C1428), is mutagenized in order to identify domains of CS involved in targeting. Since a putative targeting mechanism of CS implies phosphorylation-dependent steps in the endoplasmic reticulum (ER) and/or Golgi complex, five CS-HA1 mutants disrupting the three phosphorylation sites of CS (Thr(189), Thr(229), and Thr(353)) were engineered by either site-directed mutagenesis or deletion: CS-HA1DeltaP1 (Thr(189) --> Ile); CS-HA1DeltaP2 (Thr(229) --> Asn); CS-HA1DeltaP1,2; in which Thr(189) and Thr(229) were changed to Ile and Asn, respectively; and CS-HA1Delta14(COOH) and CS-HA1Delta49 (COOH), in which 14 residues (Glu(354)-Asp(367)) and 49 residues (Asp(319)-Asp(367)), respectively, were deleted at the carboxy-terminal. Mutant cDNAs were transiently transfected in either HeLa cells, cultured myoblasts of rat skeletal muscle, or regenerating soleus muscle fibers of adult rats. Each CS-HA1 mutant was identified by Western blot as a single polypeptide of the predicted molecular weight. The intracellular localization of CS-HA1 mutants was studied by immunofluorescence using specific antibodies against either CS or HA1. CS-HA1 mutants colocalized with ER markers, e.g., calreticulin, and partially overlapped with Golgi complex markers, e.g., alpha-mannosidase II, in HeLa cells and myotubes. CS-HA1 mutants were expressed and retained in ER and ER/SR of HeLa cells and myotubes, respectively, and correctly segregated to jSR of regenerating soleus muscle fibers. Thus, the targeting mechanism of CS in vivo is not affected by phosphorylation(s); i.e., sorting and segregation of CS appear to be independent of posttranslational phosphorylation(s).

Factors affecting exocellular polysaccharide production by Lactobacillus delbrueckii subsp. bulgaricus grown in a chemically defined medium

We developed a chemically defined medium (CDM) containing lactose or glucose as the carbon source that supports growth and exopolysaccharide (EPS) production of two strains of Lactobacillus delbrueckii subsp. bulgaricus. The factors found to affect EPS production in this medium were oxygen, pH, temperature, and medium constituents, such as orotic acid and the carbon source. EPS production was greatest during the stationary phase. Composition analysis of EPS isolated at different growth phases and produced under different fermentation conditions (varying carbon source or pH) revealed that the component sugars were the same. The EPS from strain L. delbrueckii subsp. bulgaricus CNRZ 1187 contained galactose and glucose, and that of strain L. delbrueckii subsp. bulgaricus CNRZ 416 contained galactose, glucose, and rhamnose. However, the relative proportions of the individual monosaccharides differed, suggesting that repeating unit structures can vary according to specific medium alterations. Under pH-controlled fermentation conditions, L. delbrueckii subsp. bulgaricus strains produced as much EPS in the CDM as in milk. Furthermore, the relative proportions of individual monosaccharides of EPS produced in pH-controlled CDM or in milk were very similar. The CDM we developed may be a useful model and an alternative to milk in studies of EPS production.

Myotonic dystrophy protein kinase expressed in rat cardiac muscle is associated with sarcoplasmic reticulum and gap junctions

Myotonic dystrophy (DM) is one of the most prevalent muscular diseases in adults. The molecular basis of this autosomal disorder has been identified as the expansion of a CTG repeat in the 3' untranslated region of a gene encoding a protein kinase (DMPK). The pathophysiology of the disease and the role of DMPK are still obscure. It has been previously demonstrated that DMPK is localized at neuromuscular junctions, myotendinous junctions, and terminal cisternae of the sarcoplasmic reticulum (SR), in the skeletal muscle, and at intercalated discs in the cardiac muscle. We report here new findings about specific localization of DMPK in the heart. Polyclonal antibodies raised against a peptide sequence of the human DMPK were used to analyze the subcellular distribution of the protein in rat papillary muscles. Confocal laser microscopy revealed a strong although discontinuous reactivity at intercalated discs, together with transverse banding on the sarcoplasm. At higher resolution with immunogold electron microscopy, we observed that DMPK is localized at the cytoplasmic surface of junctional and extended junctional sarcoplasmic reticulum, suggesting that DMPK is involved in the regulation of excitation-contraction coupling. Along the intercalated disc, DMPK was found associated with gap junctions, whereas it was absent in the two other kinds of junctional complexes (fasciae adherentes and desmosomes). Immunogold labeling of gap junction purified fractions showed that DMPK co-localized with connexin 43, the major component of this type of intercellular junctions, suggesting that DMPK plays a regulatory role in the transmission of signals between myocytes.

Melatonin cycle in the fiddler crab Uca pugilator and influence of melatonin on limb regeneration

Melatonin was measured over 24 hr in the eyestalks of Uca pugilator by means of radioimmunoassay; crabs were acclimatized either to a LD 12:12 photoperiod or constant darkness. A significant peak occurred at 13.00 hr in the LD 12:12 crabs. A photophase peak in melatonin has only been reported in one other species, also a crustacean. In constant darkness, two melatonin peaks occurred, one at 16.00 hr and the other 12 hr later; these results suggest that the melatonin cycle is a true circadian rhythm. HPLC with ultraviolet-visible detection was used to confirm the identity of melatonin immunoactivity. The influence of melatonin on regeneration of the walking legs was also examined: eyestalks were either removed or left intact, and limb bud length was measured every other day for at least 17 days in control and melatonin-treated crabs (60 microg ml(-1) seawater). Melatonin significantly increased the rate of limb regeneration in both eyestalk-intact and eyestalk-removed groups; this is contrary to results of regeneration studies in other phyla, in which similar melatonin concentrations inhibited regeneration.

Evidence for localization of the myotonic dystrophy protein kinase to the terminal cisternae of the sarcoplasmic reticulum

Myotonic dystrophy is an autosomal dominant multisystem disease primarily affecting skeletal muscle and is characterized by the presence of an amplified trinucleotide repeat in the 3' untranslated region of the myotonic dystrophy protein kinase gene. In this study, the subcellular localization of the myotonic dystrophy protein kinase in muscle tissues has been investigated at both morphological and biochemical level, by using antibodies against the myotonic dystrophy protein kinase. Immunofluorescence studies and Western-blot analysis were carried out with antibodies raised against both a synthetic peptide and a recombinant fusion protein fragment specific for the myotonic dystrophy protein kinase. The kinase is localized both to the surface membranes, and within the skeletal fibres in the region of the A-I band boundary. Consistent with the A-I location of the kinase is that Western-blot analysis of purified fractions from sarcoplasmic reticulum show that triads and sarcoplasmic reticulum terminal cisternae are immunoreactive for two myotonic dystrophy protein kinase proteins of different molecular weight (85 and 54 kDa). The relative amount of these two proteins is different in relation to the muscle type, the 85 kDa protein being more evident in skeletal than in cardiac fibres. In addition, immunofluorescence studies of cardiac muscle reveal a heavy concentration of DM-PK localized to the intercalated discs, as well as a weaker reaction in the sarcoplasm. These results taken together suggest that multiple isoforms of the DM-PK may exist and that they may be differentially located in muscle tissues.

A procedure to raise the tip during correction of the unilateral cleft lip nasal deformity

A method is reported for the correction of the depressed nasal tip in the cleft lip deformities. Open exposure of the nasal frame, septal chondral anterior reinsertion, and lipocutaneous composite graft taken from the submastoid or retroauricular region and positioned at the basis of the columella are the main points of the method. The first results, in 22 patients, are discussed and seem promising.

Alessandro Benedetti, a fifteenth century anatomist and surgeon: his role in the history of nasal reconstruction

Alessandro Benedetti (about 1445-1525) was Professor of Anatomy and Surgery at Padua University. He became famous for the construction of the first anatomical theater ever built, where he personally used to carry out dissections. He published articles on many subjects, first of all on anatomy. His work Anatomice, sive Historia Corporis Humani (Anatomy, or the History of the Human Body), first printed in Venice in 1502, was very popular and influential at that time. Of the many topics treated in the book, one is of special interest to plastic surgeons, i.e., the description of nasal reconstruction by means of a skin flap taken from the arm. The procedure is the same as the one the Branca family practiced in Sicily in the middle of fifteenth century. It is well known that the Brancas kept secret the operation and never published it. Hence, Alessandro Benedetti played an important role in the history of plastic surgery because he first reported in the Western surgical literature the procedure of nasal repair, later called the "Italian" method, almost 100 years before Tagliacozzi's publication in 1597.

Identification and localization of the myotonic dystrophy gene product in skeletal and cardiac muscles

We have raised a polyclonal antibody against a synthetic peptide chosen within the deduced sequence of the myotonic dystrophy gene product. This antibody binds to a protein whose molecular weight is in the range of 50-54 kDa in Western blotting of rat, rabbit and human muscles. Biochemical studies seem to indicate that this protein is a peripheral component of sarcoplasmic reticulum as well as of plasma membrane.

Calsequestrin is a component of smooth muscles: the skeletal- and cardiac-muscle isoforms are both present, although in highly variable amounts and ratios

Expression by smooth-muscle cells of calsequestrin (CS), the low-affinity/high-capacity Ca(2+)-binding protein of striated-muscle sarcoplasmic reticulum (SR), has been investigated in recent years with conflicting results. Here we report the purification and characterization from rat vas deferens of two CS isoforms, the first deemed skeletal muscle, the second cardiac type, on account of their N-terminal amino acids and other relevant biochemical and molecular properties. Compared with vas deferens, the smooth muscles from aorta and stomach, in that order, were found to express lower amounts of CS, whereas in the uterus and bladder the protein was not detectable. The ratio between the two CS isoforms was also variable, with the stomach and aorta predominantly expressing the skeletal-muscle type and the vas deferens expressing the two CSs in roughly similar amount. Because of the property of CSs to localize within the skeletal-muscle SR lumen not uniformly, but according to the distribution of their anchorage membrane proteins, the expression of the protein suggests the existence in smooth-muscle cells of discrete endoplasmic-reticulum areas specialized in the rapidly exchanging Ca2+ storage and release, and thus in the control of a variety of functions, including smooth-muscle contraction.

Dual role of calsequestrin as substrate and inhibitor of casein kinase-1 and casein kinase-2

Calsequestrin from different muscle tissues and species has been phosphorylated by casein kinase-1 and casein kinase-2, in the conditions previously reported by Cala and Jones (J. Biol. Chem. 266, 391-398, 1991). Results indicates that rabbit cardiac and skeletal calsequestrin and frog skeletal calsequestrin are phosphorylated by both casein kinase-1 and casein kinase-2, at variance with chicken skeletal calsequestrin which is a poor substrate for both enzymes. We also observed that chicken calsequestrin is able to inhibit phosphorylation of cardiac calsequestrin, as well as other specific substrates, when added together to the assay medium.

Localization of protein kinase C in skeletal muscle T-tubule membranes

Membrane fractions enriched in transverse tubules, either predominantly free or junctional, sarcoplasmic reticulum subfractions and purified sarcolemmal preparations have been isolated from rabbit skeletal muscle and examined for their contents of protein kinase C. Using activity measurements and immunoblotting methods, we have been able to detect substantial amounts of endogenous protein kinase C in T-tubules membranes and to a lesser extent, in muscle sarcolemma. Protein kinase C was found to be highest in junctional T-tubules and to be virtually absent from sarcoplasmic reticulum-derived membrane fractions. Immunofluorescence staining of muscle fibers is consistent with a T-tubule localization of the kinase. The T-tubule-associated protein kinase C enzyme phosphorylates several potentially important membrane proteins.

Dystrophin is phosphorylated by endogenous protein kinases

Dystrophin, the protein coded by the gene missing in Duchenne muscular dystrophy, is assumed to be a component of the membrane cytoskeleton of skeletal muscle. Like other cytoskeletal proteins in different cell types, dystrophin bound to sarcolemma membranes was found to be phosphorylated by endogenous protein kinases. The phosphorylation of dystrophin was activated by cyclic AMP, cyclic GMP, calcium and calmodulin, and was inhibited by cyclic AMP-dependent protein kinase peptide inhibitor, mastoparan and heparin. These results suggest that membrane-bound dystrophin is a substrate of endogenous cyclic AMP- and cyclic GMP-dependent protein kinases, calcium/calmodulin-dependent kinase and casein kinase II. The possibility that dystrophin could be phosphorylated by protein kinase C is suggested by the inhibition of phosphorylation by staurosporin. On the other hand dystrophin seems not to be a substrate for protein tyrosine kinases, as shown by the lack of reaction of phosphorylated dystrophin with a monoclonal antiphosphotyrosine antibody. Sequence analysis indicates that dystrophin contains seven potential phosphorylation sites for cyclic AMP- and cyclic GMP-dependent protein kinases (all localized in the central rod domain of the molecule) as well as several sites for protein kinase C and casein kinase II. Interestingly, potential sites of phosphorylation by protein kinase C and casein kinase II are located in the proximity of the actin-binding site. These results suggest, by analogy with what has been demonstrated in the case of other cytoskeletal proteins, that the phosphorylation of dystrophin by endogenous protein kinases may modulate both self assembly and interaction of dystrophin with other cytoskeletal proteins in vivo.

Merkel-cell carcinoma of the skin

Three cases of Merkel-cell carcinoma of the skin have been presented. The need for a correct clinical and histologic diagnosis has been highlighted. Rapid widespread growth of the tumor occurs when surgical treatment is delayed. Immunohistochemistry is essential for accurate differential diagnosis.

Purification and characterization of calsequestrin from chicken cerebellum

Chicken cerebellum microsomal fractions contain a protein tentatively identified as calsequestrin (CS) (Volpe et al., Neuron 5, 713-721, 1990). Here we report, for the first time, the purification of cerebellum CS from whole tissue homogenate by DEAE-Cellulose chromatography and Ca(2+)-dependent elution from phenyl-Sepharose. The purified cerebellum CS displays the shift and increase in intrinsic fluorescence characteristic of skeletal muscle CS, and is shown to be a high-capacity, low-affinity Ca2+ binding protein (Kd = 1 mM).

Mortality rate and prognostic indices in 2615 burned patients

Two thousand six hundred and fifteen burned patients are analysed according to mortality rate and the results are compared with other prognostic indices. Our statistical data are similar to those reported by Feller et al. (1976), but differ from those expected by Roi et al. (1983) and Bull (1971). It is suggested that other burns centres should produce their statistical figures in the same way, thereby producing a wider statistical experience and a more accurate prognostic index. The improvement in the survival rate in our centre in the past 5 years is also discussed.

Co-localization of the dihydropyridine receptor and the cyclic AMP-binding subunit of an intrinsic protein kinase to the junctional membrane of the transverse tubules of skeletal muscle

Junctional transverse tubules (TT) isolated from triads of rabbit skeletal muscle by centrifugation in an ion-free sucrose gradient were compared with membrane subfractions, predominantly derived from the free portion of TT, that had been purified from sarcoplasmic reticulum membrane contaminants by three different methods. The markers used were diagnostic membrane markers and the dihydropyridine (DHP) receptor, which is a specific marker of the junctional membrane of TT. Junctional TT have a high membrane density (Bmax. 60 pmol/mg of protein) of high-affinity (Kd 0.25 nM) DHP-binding sites using [3H]PN200-110 as the specific ligand. When analysed by SDS/PAGE under reducing conditions and by Western blot techniques, the TT were found to contain a concanavalin A-binding 150 kDa glycoprotein which probably corresponds to the alpha 2-subunit of the DHP receptor. This conclusion was supported by correlative immunoblot experiments with a specific antibody. Junctional TT are further distinguished from free TT by the presence of a high number (Bmax. 20 pmol/mg of protein) of [3H]cyclic AMP receptor sites, as determined by the Millipore filtration technique of Gill & Walton [(1974) Methods Enzymol. 38, 376-381]. Use of this method means that the number of receptors may have been underestimated. The TT-bound cyclic AMP receptor was identified as a 55 kDa protein by specific photoaffinity labelling with 8-N3-[3H]cyclic AMP, and had similar phosphorylation properties and apparent molecular mass to the RII form of the regulatory subunit of cyclic AMP-dependent protein kinase. Co-localization of the intrinsic cyclic AMP-dependent protein kinase and of the DHP receptor complex to the junctional membrane of TT supports the hypothesis that the 170 kDa alpha 1-subunit of the receptor is a substrate for the kinase.

Beta 2-microglobulins and renal dysfunction in burned patients

Studies have been made of the serum and urinary beta-microglobulin levels in 18 burns patients in order to estimate glomerular and proximal tubular dysfunction. The greatest urinary excretion of beta 2-microglobulin was found in severely burned patients during the second and third weeks after injury. Urinary measurements of this protein in patients with renal tubular dysfunction have proved to be of value in the assessment of renal tubular damage.

The use of Omiderm, a new skin substitute, in a burn unit

The use of a new synthetic material for temporary dressing of burn surfaces and skin donor sites is reported. Forty-six patients whose burns were divided into superficial dermal, deep dermal and full thickness post-escharectomy areas and donor sites are presented. For each group of patients the evolution of the wounds and the final results are described.

[Changes in the concentration of urinary homovanillic acid as a prognostic factor in patients treated for malignant melanoma]

In 34 patients with malignant melanoma in three different stages HVA concentrations were determined. Some patients in stage 1 presented a considerable discrepancy between concentration values and values reported in other works. This group had been controlled for three years to observe the development of disease. We found three subgroups: the first with values within 4,3-6.0 mg/24 hr haven't had any recurrence; the second with values within 6.8-11.75 mg/24 hr presented lymphonodal metastasis in the lapse of six months - 1 year; in the third with values within 10-20 mg/24 hr patients died in two years for disseminated metastasis. The Authors according to the results achieved, conclude that variation of HVA concentration will be further prognostic factor.

[Reconstruction of the breast after radical mastectomy]

The Authors review the indications for mammary reconstruction following mastectomy, and add a new series of procedures after considering the oldest ones. They point out the possible post operative complications and evaluate the result of a reconstruction which can prove useful both cosmetically and psychologically.