The role of operative arthroscopy for the diagnosis and treatment of lesions about the distal ulna

Operative arthroscopy of the wrist compliments the physical examination and radiographic imaging to improve diagnosis and treatment of lesions about the distal ulna. This article reviews the relevant anatomy, biomechanics, and classification of acute and degenerative lesions of the triangular fibrocartilage complex (TFCC). Minimally invasive diagnostic and management techniques for TFCC tears are described in detail.     

Efficacy of anterior, posterior and total fundoplication in an experimental model

BACKGROUND: This study examined the effect of different types of laparoscopic fundoplication on an incompetent lower oesophageal sphincter to test their effectiveness at preventing gastro-oesophageal reflux in the early postoperative period. METHODS: An experimental porcine model was used. Initial oesophageal myotomy ensured an incompetent lower oesophageal sphincter with free reflux of 'intragastric fluid'. Anterior, posterior or total fundoplication was then performed laparoscopically in 15 laboratory pigs (five in each group). Fundoplication competence and efficacy were determined 2 weeks after laparoscopic antireflux surgery by inflating the stomach with liquid through a gastrostomy cannula. Some animals were also studied at 4 and 6 weeks. Lower oesophageal sphincter pressure was determined using a water-perfused oesophageal manometry catheter incorporating a Dent sleeve. RESULTS: All three types of fundoplication produced similar increases in postoperative resting lower oesophageal sphincter pressure and restored adequate competence to the gastro-oesophageal junction. CONCLUSION: All three variants of laparoscopic fundoplication restore gastro-oesophageal competence in the early postoperative period.     

Temporary vascular occlusion during cerebral aneurysm surgery

Mood disorders and attention deficit-hyperactivity disorder (ADHD) co-occur in 20-30% of children and adolescents diagnosed in both epidemiological and clinical studies, but little information is available regarding cognitive factors that may be relevant to the expression of co-occurring mood disorders and ADHD. This study examined whether ADHD with and without a comorbid mood disorder could be differentiated on the basis of cognitive factors associated with prominent theories of depression. Children meeting diagnostic criteria for ADHD (n = 14) or ADHD and a comorbid mood disorder (n = 27) were assessed on a variety of cognitive indices. Children in the comorbid group reported more negative views of themselves and a more depressogenic attributional style. Cognitive disturbances associated with A. T. Beck's (1967) cognitive model and attributional style theories of depression differentiate ADHD children with significant mood pathology.     

The anti-ischemic properties of new specific bradycardic agents, derivatives of 2-mercaptobenzimidazole

Experiments on narcotized cats demonstrated that the derivatives of 2-mercaptobenzimidazole possessing the properties of specific bradycardic agents and coded as CM-251, CM-266, and CM-345, reduce the mean rise of segment ST on numerous leads of the epicardial electrogram during 5-min occlusion of the anterior descending branch of the left coronary artery. The agents stabilize the heart pumping and contracting functions under conditions of 30- and 60-min reperfusion of the coronary artery, respectively. It is concluded on the grounds of the obtained data that the 2-mercaptobenzimidazole derivatives possess a marked anti-ischemic action.     

Differentiation-specific enhancer activity in transduced keratinocytes: a model for epidermal gene therapy

Active sequences from the laminin alpha1 and alpha2 chain carboxyl-terminal globular domains (G domain) have been identified by screening overlapping synthetic peptides in a number of biological assays (Nomizu et al. [1995] J. Biol. Chem. 270:20583-20590; Nomizu et al. [1996] FEBS Lett. 396:37-42). We have tested the activity of these peptides in submandibular gland explants of embryonic day 13 mice to determine the functional sites involved in organ development. The laminin alpha1 chain peptide, RKRLQVQLSIRT (residues 2719-2730 and designated AG-73), significantly inhibited epithelial branching morphogenesis. In contrast, other cell adhesive laminin alpha1 chain peptides including the AASIKVAVSADR and NRWHSIYITRFG failed to inhibit the branching. MG-73, a homologue of AG-73 from the laminin alpha2 chain, did not inhibit the branching. The alpha2 chain peptide had no effect, which may be due to the low levels of this laminin chain in day 13 mice. Laminin alpha2 chain-specific monoclonal antibodies strongly reacted with the basement membranes of developed acini but only weakly stained embryonic day 13 submandibular epithelium. The expression of E-cadherin and alpha6 integrin, as detected by immunofluorescence, were unchanged in both AG-73 and control scramble peptide-treated epithelial cells of the explants. In contrast, immunostaining of nidogen/entactin showed that explants treated with AG-73 for 3 days had a discontinuous basement membrane. Explants treated for 3 days with control peptide showed a normal basement membrane. These results suggest that the region containing the AG-73 sequence of the laminin alpha1 chain is crucial for development of submandibular gland at early embryonic stages. The discontinuous basement membrane in AG-73-treated explants may indicate an important role for this region in basement membrane assembly.     

Protein-protein and protein-DNA interactions in the type I restriction endonuclease R.EcoR124I

The type I restriction-modification system EcoR124I recognizes and binds to the split DNA recognition sequence 5'-GAAN(6)RTCG-3'. The methyltransferase, consisting of HsdM and HsdS subunits with the composition M2S, can interact with one or more subunits of the HsdR subunit to form the endonuclease. The interaction of the methyltransferase with HsdR has been investigated by surface plasmon resonance, showing that there are two non-equivalent binding sites for HsdR which differ in binding affinity by at least two orders of magnitude. DNA footprinting experiments using Exonuclease III suggest that the addition of HsdR to the methyltransferase (at a stoichiometry of either 1:1 or 2:1) increases the stability of the resulting DNA-protein complex but does not increase the size of the footprint. More extensive in situ footprinting experiments using copper-phenanthroline on the DNA-protein complexes formed by M2S, R1M2S and R2M2S also show no difference in the detailed cleavage pattern, with approximately 18 nucleotides protected on both strands in each complex. Thus the HsdR subunit(s) of the endonuclease stabilise the interaction of the M2S complex with DNA, but do not directly contribute to DNA binding. In addition, the thymidine nucleotide in the tetranucleotide recognition sequence GTCG is hyper-reactive to cleavage in each case, suggesting that the DNA structure in this region is altered in these complexes.     

Venezuelan field trials of vaccines against brucellosis in swine

We have investigated the inter-relationship between the opioid and aminergic systems in the control of secretion of the pro-oestrous LH surge and the involvement of delta-opioid receptor subtypes in this process. Conscious female rats bearing a cannula in the femoral artery were injected i.p. with a selective delta-opioid receptor agonist (DPDPE) either alone or with the opioid antagonist (naloxone) at 1300 h on the day of pro-oestrus. Blood samples were collected hourly between 1500 h and 1900 h, and plasma LH levels were measured by RIA. At the end of this period (1900 h), the animals were autopsied and the concentrations of the amines (noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5HT)) and their metabolites (dihydroxyphenolglycol (DHPG) and 5-hydroxyindoleacetic acid (5HIAA), metabolites of NA and 5HT respectively) were determined by HPLC with electrochemical detection in the medial preoptic area, suprachiasmatic nucleus, median eminence and arcuate nucleus. DPDPE abolished the LH surge and concomitantly decreased hypothalamic NA and DHPG concentrations in all the areas examined. The levels of DA, 5HT and 5HIAA were also reduced in all hypothalamic regions studied, except DA and 5HIAA in the suprachiasmatic nucleus. Naloxone reversed these inhibitory effects of the delta-agonist. We conclude that activation of delta-opioid receptors may exert an inhibitory effect on LH release. The effect is probably an indirect one mediated by the monoaminergic systems, as they are suppressed by DPDPE in nearly all the hypothalamic regions studied.