Different beta-adrenergic receptor density in different rat skeletal muscle fibre types

The effects of adrenaline on skeletal muscle differ between fibre types. The aim of the present study was to investigate the beta-adrenoceptor density, affinity and subtype in rat skeletal muscles with different fibre type composition. beta-Adrenoceptors were determined in cryostat sections to avoid methodological problems with variable recovery, using the non-selective beta-adrenoceptor ligand [3H]CGP-12177 and beta 1- and beta 2-selective cold ligands CGP 20712A and ICI 118,551. In the presence of protease inhibitors [3H]CGP-12177 binding was stable, saturable, reversible, and displaceable. Scatchard analysis of binding saturation data was compatible with a single class of specific binding sites. Binding site density (Bmax) was higher (P < 0.02) in adult soleus (9.38 +/- 1.13 fmol x mg protein-1) than in adult extensor digitorum longus (4.74 +/- 0.39 fmol x mg protein-1), whereas the dissociation constants (Kd), 0.37 +/- 0.05 and 0.31 +/- 0.04 nM for soleus and extensor digitorum longus, respectively, were not significantly different. For young rats (5-6 weeks), Bmax was 11.21 +/- 0.33 and 5.45 +/- 0.11 fmol x mg protein-1 (P < 0.05), and Kd was 0.27 +/- 0.02 and 0.24 +/- 0.04 nM for soleus and epitrochlearis, respectively. These results correspond to a receptor density of 2 and 1 pmol x g w.wt.-1 in muscles containing.mainly type I and type II fibres, respectively. Displacement studies with CGP 20712A and ICI 118,551 were compatible with mainly beta 2-adrenoceptors, but 7-10% beta 1-adrenoceptors were present in both types of muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Islet expression of Rhombotin and Isl-1 suggests cell type specific exposure of LIM-domain epitopes

The homeodomain protein Isl-1 and the proto-oncogene Rhombotin (a LIM-only protein), share a double zinc-binding LIM domain and have both been implicated in neural and possibly endocrine development. Isl-1 is expressed in all endocrine cell-types of the islet of Langerhans while Rhombotin mRNA expression was reported in rat insulinoma cells. We have cloned and sequenced Rhombotin cDNA from rat insulinoma (99.4% identical to human and mouse sequences) and demonstrate that it is expressed in normal islets, intestinal tissue, and testis, in addition to the brain; but absent in all other organs tested. Rhombotin mRNA is expressed in phenotypically distinct islet tumours (α-, β, and δ-tumours) at levels comparable to that of normal islets. Antisera raised against two distinct epitopes contained within a short synthetic peptide representing part of the N-terminal LIM domain of Rhombotin surprisingly stain α- and δ-cells, respectively, on sections of rat pancreas. Rhombotin is undetectable by immunocytochemistry using LIM-domain antisera on intact monolayer islet tumor cells or transfected fibroblasts while readily detectable when equipped with a FLAG epitope, as detected with FLAG antiserum. In contrast, recombinant FLAG-Rhombotin is efficiently recognised by Western blotting or immunoprecipitation with all LIM-specific antisera. Almost identical results were obtained with LIM-specific versus homeodomain/C-terminal Isl-1 antisera staining α-cell cytoplasm or all islet nuclei, respectively. We conclude that Rhombotin in addition to Isl-1 is expressed in the islet of Langerhans and propose that the differential staining patterns obtained with antisera towards the LIM domains versus flanking epitopes of both proteins reflect (1) cell-specific protein-protein interactions of these domains or, alternatively, (2) islet cell type specific expression of novel homologous LIM domain proteins.

Myxoid liposarcoma of the anterior mediastinum. Diagnosis by fine needle aspiration biopsy

The mediastinum is an uncommon primary site of liposarcoma, which constitutes < 1% of tumors at that site. We report a case of myxoid liposarcoma evaluated with fine needle aspiration biopsy in a 66-year-old male who presented with cardiac tamponade, superior vena cava syndrome and radiologic evidence of a large anterior mediastinal mass. Cytologically the neoplastic cells were strikingly dyscohesive, with ovoid or spindle-shaped, hyperchromatic nuclei. The cytoplasm was abundant and often finely vacuolated with lipid. They were associated with a prominent myxoid, intercellular substance and distinct, arborized capillary structures. Survival is influenced by the tumor cell type and differentiation. The overall prognosis seems to be poorer than that of liposarcomas occurring in other areas. To the best of our knowledge, this is the first reported case of primary mediastinal liposarcoma diagnosed by fine needle aspiration biopsy.

Adrenaline stimulated glycogen breakdown in rat epitrochlearis muscles: fibre type specificity and relation to phosphorylase transformation

The effect of adrenaline on glycogen breakdown in different skeletal muscle fibre types was investigated in the epitrochlearis muscle in vitro. Histochemical studies showed that adrenaline stimulated glycogen breakdown in all three major fibre types, with a higher absolute glycogen breakdown in type IIB fibres compared to type IIA and type I fibres. In biochemical studies we found that the glycogenolytic rate decreased during prolonged incubation with adrenaline, although the percentage phosphorylase in the a form and the concentration of glucose-6-phosphate (G-6-P) remained high. In the dose response studies we found an EC50 of 2.2 x 10(-8) M adrenaline for adrenaline stimulated glycogen breakdown, with an EC50 of 2.0 x 10(-7) M for adrenaline stimulated accumulation of G-6-P, excluding G-6-P as the key inhibitor of phosphorylase a activity.

Developmental and symptom specificity of hopelessness, cognitive errors, and attributional bias among clinic-referred youth

The present study examined the unique and interactive relationships between age and indices of psychopathology (i.e., anxiety, aggression, and depression), with three types of maladaptive cognitions: hopelessness, negative cognitive errors, and attributional bias. Some negative cognitions were not unique to depression and were associated with broader psychopathology. Developmental considerations also influenced some negative cognitions or qualified the association between negative cognitions and depression.

Characterization of trout galanin and its distribution in trout brain and pituitary

Galanin was purified from an extract of the stomach of the rainbow trout, Oncorhynchus mykiss, and its primary structure was established as Gly-Trp-Thr-Leu-Asn-Ser- Ala-Gly-Tyr-Leu10-Leu-Gly-Pro-His-Gly-Ile-Asp-Gly-His-Arg20- Thr-Leu-Ser-Asp- Lys-His-Gly-Leu-Ala. Trout galanin shows six amino acid substitutions compared with pig galanin, but the N-terminal region (residues 1-14) has been fully conserved. The distribution of galanin-immunoreactive (GAL-IR) structures in the trout brain and pituitary was studied via immunohistochemistry. GAL-IR cell bodies were observed only in the caudal telencephalon, the preoptic region, and the mediobasal hypothalamus. GAL-IR fibers, however, are widely distributed throughout the brain, with a much lower density in the midbrain and posterior brain than in the tel- and diencephalon. Particularly dense innervation of the mediobasal hypothalamus, the ventral and supracommissuralis parts of the caudal telencephalon, and the region above and below the anterior commissure was observed. A heavy innervation of the pituitary was consistently detected. GAL-IR fibers were present in neurohypophyseal digitations of both the anterior and intermediate lobes with highest density in the region of the proximal pars distalis, where growth hormone and gonadotropic cells are located. Fibers were also seen in digitations of the rostral pars distalis, in particular between the prolactin follicles. The distribution of GAL-IR neurons in the central nervous system and pituitary of the trout suggests that the peptide may exercise an important role in the regulation of neuroendocrine functions, particularly those related to reproduction.

The role of phagocytic cells in resistance to disseminated candidiasis in granulocytopenic mice

This study assessed the involvement of phagocytic cells in murine resistance to disseminated candidiasis of endogenous origin. SCID mice and their immunocompetent CB.17 (BALB/c) counterparts were colonized with a pure culture of Candida albicans and treated with an antigranulocyte monoclonal antibody (anti-Gr-1), polyinosinic:polycytidylic acid (poly[I.C]), or both to impair macrophage function in vivo. Candida-colonized SCID mice were more susceptible to disseminated candidiasis after treatment with anti-Gr-1 or poly(I.C) than were CB.17 mice. Histopathology of orogastric tissues demonstrated that combined treatments with anti-Gr-1 and poly(I.C) also enhanced the susceptibility of SCID and CB.17 mice to orogastric candidiasis. These data indicate that macrophages as well as granulocytes play an important role in host resistance to mucosal and disseminated candidiasis of endogenous origin.

A retrospective analysis of 279 patients with isolated mandibular fractures treated with titanium miniplates

PURPOSE

This article addresses the suitability of semirigid fixation for the treatment of mandibular fractures.

MATERIALS AND METHODS

Between 1986 and 1991, 279 patients with 447 isolated mandibular fractures were treated with miniplate fixation using the tension-band principle of Champy et al. The time from trauma to treatment, etiology, number and location of the fractures, and the presence of preoperative infection and neurosensory disturbances were recorded. Postoperative complications such as infections, neurosensory disturbances, malocclusion, and nonunions also were recorded, as well as the reasons for removal of the miniplates.

RESULTS

Postoperative infection occurred in 10 patients (3.6%). These infections were controlled by antibiotics and the miniplates were removed after the acute phase. Occlusion disturbances were noted postoperatively in 13 patients (4.7%), and they were corrected by minimal occlusal grinding in the majority of cases. Neurosensory disturbances were noted preoperatively in 26.9% of the patients and 12 months postoperatively in 1.4% of the patients. Forty-seven plates (8.1%) in 32 patients (11.5%) were removed for a variety of reasons. No cases of nonunion occurred.

CONCLUSION

Semirigid fixation of mandibular fractures with miniplates is a viable treatment option for the management of such injuries.

Humoral and cellular immune responses to enolase after alimentary tract colonization or intravenous immunization with Candida albicans

Immune responses to defined antigens of the AIDS opportunistic pathogen Candida albicans that arise as a consequence of alimentary tract colonization or induced candidemia were assessed. Lymphocyte activation and antibody production to the abundant immunodominant antigen enolase were evident in germfree mice colonized with C. albicans. Lymphocytes from colonized or intravenously challenged mice responded to a recombinant C. albicans enolase fusion protein (EFP). The responses to EFP were significantly higher than the responses to a control protein, glutathione S-transferase. In immunoblotting experiments, enolase was the immunodominant humoral immunogen in these mice. These results demonstrate that enolase stimulates cellular and humoral responses and that specific immune responses to enolase are sensitive indicators of the presence of proliferating C. albicans in mice.

Obsessive-compulsive disorder: admission patterns and diagnostic stability. A case-register study

All first-time admissions from 1970 to 1986 with obsessive-compulsive neurosis (OCD) (ICD-8 diagnosis number 300.39) or obsessive-compulsive personality disorder (OCPD) (ICD-8 diagnosis number 301.49) were analyzed based on an extract from the nationwide Psychiatric Case Register in Denmark. All patients with secondary diagnoses other than neurotic disorders or personality disorders (including "neuroses characterogenes") were excluded from the study. A total of 284 patients were first-time admitted with a main diagnosis of OCD during the period. The sex ratio was 0.67 (males/females). A total of 126 were first-time admitted with a diagnosis of OCPD, with a sex ratio of 1.18 (males/females). Seventy-seven percent of the readmitted patients with a first-time diagnosis of OCD kept a diagnosis within the "emotional spectrum" at the last admission. About half kept OCD as a main diagnosis, whereas only 15% shifted to a severe psychiatric diagnosis such as schizophrenia or manic-depressive psychosis. Of the readmitted patients with OCPD, 13% later developed a diagnosis of manic-depressive psychosis.

Prospective, randomized, endoscopic-blinded trial comparing precolonoscopy bowel cleansing methods

PURPOSE

Recent reports have suggested that precolonoscopy bowel preparation is easier to tolerate if a small volume solution is used. Therefore, the aim of this study was to compare three oral solutions for colonoscopy to determine any changes in either patient compliance or cleansing ability.

METHODS

Four hundred fifty patients were prospectively randomized to receive either a standard 4-liter polyethylene glycol solution, a newer sulfate-free 4-liter polyethylene glycol solution, or a 90-ml oral sodium phosphate preparation. Before and after bowel preparation all patients were weighed, and serum electrolytes as well as phosphate, magnesium, calcium, and osmolarity were measured. In addition, a detailed questionnaire was used to assess side effects and patient satisfaction. Endoscopists blinded to the type and quantity of preparation used scored the type of residual stool and the percentage of bowel wall visualized for each segment of colon and for the overall examination. Nurses recorded all procedure times as well as the quantity of irrigation and aspiration.

RESULTS

Four hundred twenty-two age-matched and sex-matched patients completed all phases of the trial. There were no clinically significant changes in weight or in any biochemical parameters. There was, however, asymptomatic hyperphosphatemia in the sodium phosphate group (P < 0.01). The length of time to the cecum was similar for all three groups, with a higher volume of fluid suctioned for sodium phosphate (P < 0.01). Overall, endoscopists scored sodium phosphate as "excellent" or "good" in 90 percent vs. 70 percent and 73 percent after the polyethylene glycol or sulfate-free lavage, respectively (P < 0.01). Particulate or solid stool was found in all segments of the colon more frequently after both large volume preparations than after sodium phosphate (P < 0.05). There were no significant differences in the frequency or intensity of any of the 11 side effects questioned. Eighty-three percent of the patients who received the sodium phosphate preparation stated they would take this same preparation again, vs. only 19 percent and 33 percent for polyethylene glycol and the sulfate-free lavage, respectively (P < 0.01).

CONCLUSION

The smaller volume oral sodium phosphate was not associated with any clinically significant problem, caused no increase in the incidence of side effects, was preferred by patients, and was more effective in colonic cleansing. However, the hyperphosphatemia seen may limit its use in patients with impaired renal function.

Nerve transposition and implant placement in the atrophic posterior mandibular alveolar ridge

The results obtained with a modified surgical technique for transposition of the inferior alveolar nerve followed by immediate placement of endosseous implants in mandibles with moderate to severe atrophy are presented. Ten transpositions of the inferior alveolar nerve together with the installation of 21 implants were performed in six patients. The mean postoperative follow-up time was 23 months, with a range of 12 to 46 months. All implants with functioning pontics remained stable, with no mobility nor signs or symptoms of pain and infection during the follow-up period. Postoperative radiographic evaluation disclosed no pathologic bone loss around the implants. Neurosensory evaluation was performed using the two-point discrimination test. One patient with unilateral transposition had objective neurosensory dysfunction at 12 months postoperative, although all the nerve function were reported as normal by the patients. Strict patient selection criteria are necessary, with full awareness by the patient of the possibility of long-term or even permanent nerve paresthesia, when this procedure is contemplated.