[Re-coronary artery bypass grafting for anomalous origin of left coronary artery from pulmonary artery (Bland-White-Garland syndrome) after operation in infancy: a case of 18-year follow-up]

Anomalous origin of the left coronary artery from the pulmonary artery is a very rare congenital malformation. Re-coronary artery bypass grafting was performed in a 18-year-old man who had received coronary artery reconstruction with a homologous saphenous vein (from his mother) at 7-months old. After the first operation, clinical course was uneventful, but the patient became symptomatic because of effort angina at age 15. The electrocardiogram showed abnormal ST segments in Lead V2-5 and abnormal T waves in Lead V5-6. Coronary arteriography revealed that saphenous vein graft was occluded. The left internal thoracic artery (LITA) was anastomosed to the left anterior descending artery and a two coronary system was established. Postoperative angiography revealed that LITA was patent, and relief of angina was obtained.

Clozapine effects on glucose metabolic rate in striatum and frontal cortex

Eighteen patients with schizophrenia had cerebral metabolic rates assessed with positron emission tomography during a double-blind, placebo-controlled crossover study of clozapine treatment. Relative metabolic rates were increased in the basal ganglia, especially on the right side. In the frontal lobe, metabolic rates were lowered, more on the left than on the right. The anterior nuclei of the thalamus also showed lower metabolic rates after clozapine. We have previously observed patients with schizophrenia to have low metabolic rates in the basal ganglia and to lack the normal right > left asymmetry; in this study, clozapine normalized striatal activity. In the frontal lobe, asymmetry was normalized, but hypofrontal function was, if anything, exaggerated. This effect in the frontal lobe was not observed with haloperidol in earlier studies. The cortical effects of clozapine may be related to its unique clinical properties and suggest important differences between typical and atypical antipsychotic drugs.

Characteristic karyotypic features in lacrimal and salivary gland carcinomas

Short-term cultures from 12 non-squamous cell carcinomas (NSCCs) of the head and neck were cytogenetically investigated. Three tumours were acinic cell carcinomas, two adenoid cystic carcinomas, three mucoepidermoid carcinomas, two carcinomas in pleomorphic adenoma, and two adenocarcinomas. Clonal chromosome aberrations were detected in all but one adenocarcinoma. Including our data, a total of 40 head and neck NSCCs with clonal aberrations have been described. Deletions of the long arm of chromosome 6 are the most common aberrations (11/40 cases); they have been detected in all types of NSCC except carcinoma in pleomorphic adenoma. Two aberrations seem to be closely associated with tumour type: t(6;9)(q21-24;p13-23), which has been seen in three of 11 adenoid cystic carcinomas (in two as the sole aberration), and structural rearrangements of 8q12-13, which have been detected in three of four carcinomas in pleomorphic adenoma.

An immunocytochemical study of bone morphogenetic protein in experimental fracture healing of the rabbit mandible

A monoclonal antibody raised against bone morphogenetic protein (BMP-McAb) has been used to demonstrate the presence of bone morphogenetic protein (BMP) in experimental fracture healing. Rabbit mandibles were fractured using standardized methods and left to heal for 3, 7, 14, 21 and 24 d, respectively. The avidin-biotin complex (ABC) method demonstrated an accumulation of positively stained primitive mesenchymal cells at the fracture site in the hematoma stage of bone repair. These cells appeared to undergo differentiation into positively-stained chondroblasts and osteoblasts during the phase of callus formation. Undifferentiated mesenchymal cells showed a high positive reactivity in the early post-fracture stages but a much lower reactivity during the remodelling phase. The results of our study suggest that bone inductive processes are accompanied by the presence of BMP in osteoprogenitor cells during fracture healing of the mandible and that BMP may play a significant role in osteogenesis during bone healing.

The toxic effects, GSH depletion and radiosensitivity by BSO on retinoblastoma

Retinoblastoma is the most common intraocular malignant tumor in children. Previous investigations have reported that buthionine sulfoximine (BSO) can deplete intracellular glutathione (GSH) by specific inhibition and increase cellular radiosensitivity. The toxic effects, GSH depletion and radiosensitivity of BSO on retinoblastoma cells are reported in this paper. GSH content of retinoblastoma cell lines Y-79, So-Rb50 and retinoblastoma xenograft is 2.7 +/- 1.3 x 1.0(-12) mmol/cell, 1.4 +/- 0.2 x 1.0(-12) mmol/cell, and 2.8 +/- 1.2 mumol/g, respectively. The ID50 of BSO on Y-79 and So-Rb50 in air for 3 h exposure is 2.5 mM and 0.2 mM, respectively. GSH depletion by 0.1 mM BSO for 24 h on Y-79 cells and 0.01 mM BSO for 24 h on So-Rb50 cells is 16.35%, and 4.7% of control. GSH depletion in tumor and other organ tissues in retinoblastoma-bearing nude mice after BSO administration is differential. GSH depletion after BSO exposure in Y-79 cells in vitro decreases the Do value of retinoblastoma cells. The SER of 0.01 mM and 0.05 mM BSO for 24 h under the hypoxic condition is 1.21 and 1.36, respectively. Based on these observations, the authors conclude that BSO toxicity on retinoblastoma cells depends on the characteristics of cell line and that BSO can increase hypoxic retinoblastoma cells' radiosensitivity in vitro. Further study of BSO radiosensitization on retinoblastoma in vivo using nude mouse xenograft is needed.

Quantitative cellular and nuclear volumetric alterations in epithelium from lichen planus lesions of human buccal mucosa

Patients with oral lichen planus lesions may represent a relatively high risk population for subsequent development of oral cancer. Little is known of the relative effects of chronic inflammation and the process of malignant transformation itself on the histological structure of transforming epithelia. We have assessed cellular and nuclear volumes in defined basal and spinous cells from normal buccal mucosa epithelium, from epithelium associated with a non-specific chronic inflammatory infiltrate and from lichen planus lesions. Normal (N) tissues were obtained from the margins of non-neoplastic buccal mucosa lesions. Inflammatory (INF) lesions were from areas of the buccal mucosa diagnosed clinically as traumatic irritation without ulceration, and lichen planus (LI) lesions were biopsied from areas exhibiting Wickham's striae. Basal and spinous epithelial cells from normal and pathological human buccal mucosa were measured on haematoxylin and eosin-stained sections imaged through a video camera using a Zeiss VIDAS analyser and from these measurements, nuclear (VN) and cellular (VCELL) volumes were determined. VN and VCELL derived for both basal and spinous strata were similar in N and INF groups but were almost doubled in the LI group. Comparisons between LI and all other groups were significantly elevated. The effects of the inflammatory infiltrate on the oral epithelium in lichen planus and in non-specific inflammation thus differ significantly. VN and VCELL may serve as potential discriminators between benign lesions and premalignant lichen planus.

A processed form of the Spatzle protein defines dorsal-ventral polarity in the Drosophila embryo

Stein et al. (1991) identified a soluble, extracellular factor that induces ventral structures at the site where it is injected in the extracellular space of the early Drosophila embryo. This factor, called polarizing activity, has the properties predicted for a ligand for the transmembrane receptor encoded by the Toll gene. Using a bioassay to follow activity, we purified a 24 × 10(3) M(r) protein that has polarizing activity. The purified protein is recognized by antibodies to the C-terminal half of the Spatzle protein, indicating that this polarizing activity is a product of the spatzle gene. The purified protein is smaller than the primary translation product of spatzle, suggesting that proteolytic processing of Spatzle on the ventral side of the embryo is required to generate the localized, active form of the protein.

Solvent effects on the conformation of cyclo(-D-Trp-D-Asp-Pro-D-Val-Leu-). An NMR spectroscopy and molecular modeling study

The conformations of cyclo(-D-Trp-D-Asp-Pro-D-Val-Leu-) in dimethyl sulfoxide-d6 (DMSO-d6) and water were determined using two-dimensional nuclear magnetic resonance spectroscopy and restrained molecular dynamics. Comparisons were made between conformations of the cyclic pentapeptide in both solvents. The NMR study revealed that, while the backbone remained relatively unchanged in both solvents, the side-chains adopted distinctly different orientations in DMSO-d6 vs. H2O. A modeling study, minus NOE constraints, produced a set of low-energy conformers possessing agreement in backbone conformation with the NMR-derived structures; however, lowest-energy conformers did not have this agreement. These results show that different solvents can significantly affect the preferred side-chain conformation of small cyclic peptides in solution. This finding will impact the selection of solvent when determining structures for use as templates in rational drug design.

Tissue reactions to titanium implants containing bovine bone morphogenetic protein: a scanning electron microscopic investigation

Cylindric titanium implants treated with bovine bone morphogenetic protein (bBMP) (Group I) and with bovine serum albumin (BSA) (Group II) were implanted in the edentulous mandibles of 15 adult dogs. They were examined 1, 2, 4, 8, and 12 weeks after insertion of the implants by scanning electron microscopy (SEM). In all specimens from Group I, active bone formation had occurred between the implant and host bone, with a well-adapted fit between the implant and the newly formed bone 4 weeks after implantation. The surrounding bone was of normal structure by week 8. However, 3 months after implantation, fibrous tissue was consistently seen surrounding parts of the implants in Group II. The results of this study suggest that the implants treated with bBMP are capable of forming new bone of normal structure at a faster rate than BSA controls and that this new bone is closely adapted to the implant surface.

Characterization of alpha 2-adrenoceptor binding sites in rabbit ciliary body membranes

PURPOSE

This study sought to identify and characterize subtypes of alpha 2-adrenoceptors in rabbit ciliary body.

METHODS

Radioligand binding assays were performed with the alpha 2-agonist ligand [125I]-p-iodoclonidine ([125I]PIC) and the antagonist ligand [3H]rauwolscine.

RESULTS

Both [125I]PIC and [3H]rauwolscine bound to a single population of receptors in membrane preparations of rabbit ciliary body. The densities for the two ligands were the same (about 640 fmol/mg). However, the affinity of [125I]PIC (dissociation constant, Kd = 1.91 +/- 0.24 nM) was about threefold higher than that of [3H]rauwolscine (dissociation constant = 6.79 +/- 1.5 nM), and binding of [125I]PIC exhibited guanine nucleotide sensitivity. Inhibition of [125I]PIC binding by epinephrine, idazoxan, and amiloride was examined to differentiate between alpha 2-adrenoceptors and the imidazoline-preferring receptor. Epinephrine and idazoxan competed for all of the [125I]PIC binding; relative potency was epinephrine > idazoxan >> amiloride. Subtypes of alpha 2-adrenoceptors were further studied by competition for [125I]PIC binding by subtype-selective compounds. [125I]PIC binding sites showed the pharmacologic characteristics of an alpha 2A-adrenoceptor (oxymetazoline > chlorpromazine >> prazosin), and competition by oxymetazoline and chlorpromazine was best fit by a one-site model. Likewise, the relative potency of inhibition of [3H]rauwolscine binding was oxymetazoline > chlorpromazine. However, inhibition of [3H]rauwolscine-binding by oxymetazoline was better fit by a two-site model, which was converted to a one-site model in the presence of 100 microM 5'-guanylimidodiphosphate.

CONCLUSIONS

A large number of alpha 2-adrenoceptors are present in rabbit ciliary body. They are not the imidazoline-preferring receptor but are alpha 2-adrenergic-specific receptors of the alpha 2A subtype.

The transport of two iron chelators, desferrioxamine B and L1, across Caco-2 monolayers

The transport of two iron chelators, desferrioxamine B (DFO) and L1 (1,2-dimethyl-3 hydroxypyridin-4-one) has been studied in vitro using the human adenocarcinoma cell line, Caco-2. The transport of DFO and L1 has also been compared with that of their iron-bound complexes, ferrioxamine (FO) and L1(3)-Fe, respectively. We report an apparent permeability coefficient (Papp) value for DFO of 0.170 x 10(-7) +/- 0.080 cm s-1. The Papp value of L1 was 1.297 x 10(-5) +/- 0.133 cm s-1. The Papp values of their iron bound complexes FO and L1(3)-Fe are 0.230 x 10(-7) +/- 0.065 cm s-1 and 2.356 x 10(-6) +/- 0.365 cm s-1, respectively. We have shown that the transport of DFO and FO is similar in the Caco-2 cell system. The transport of L1, however, is greatly reduced when complexed to iron. The value for total uptake after 60 min for DFO into the Caco-2 cells was 1.49 +/- 0.09 x 10(-3) nmol per filter. The values for total uptake after 60 min for L1 and L1(3)-Fe were 0.37 +/- 0.03 nmol per filter and 0.04 +/- 0.01 nmol per filter, respectively. Our results indicate that the poor oral bioavailability of DFO can be attributed to the low epithelial permeability of the molecule coupled with its size (mol wt 656). In contrast, the oral bioavailability observed with L1 is due to the high lipophilicity and low molecular weight (mol wt 139) of the molecule. We believe that these differences between the two molecules account for L1 being better orally absorbed than DFO.

Influence of alloferin on neuromuscular function in myasthenia patients undergoing thymectomy

Myasthenia gravis patients are hypersensitive to nondepolarizing relaxants, such as alcuronium, an intermediate-long nondepolarizing agent. This study observed the effects of alcuronium treatment in myasthenia gravis patients as compared with non-MG patients during operation. Ten MG patients (Ossermann class I-IV, scheduled for thymectomy) and 10 non-MG patients (ASA class I-II, scheduled for operation) were selected. An induction dose of alcuronium 0.2 mg/kg and thiopental 4-6 mg/kg was given, followed by intubation and ventilation with 50% nitrous oxide in oxygen and 0.5-1.5% ethrane. Neuromuscular transmission was monitored using an accelerograph and degrees of neuromuscular function at different depths were recorded. There were statistically significant differences between the two groups. The effect of alloferin in the MG group was quicker and deeper. This study also found a relation between MG class and the recovery of respiration: Respiratory recovery was quicker in classes I-II than in classes III-IV.

[Experimental study of changes in biomechanical properties of pig skin after rapid expansion]

The purpose is to evaluate the biomechanical properties of conventional skin expansion, rapid expansion and unexpanded skin. In four pigs, 240 ml expanders of square shape are placed. The flaps are divided into three groups: (1) Rapid expansion flap: the expander is inflated daily until maximum volume is obtained. (2) Conventional expansion flap: inflation is done weekly. (3) Unexpanded skin is used as control. By using the tensometer, the skin is evaluated for stress strain, stress relaxation, density of strain energy, parameters of strength, and a mathematical model is obtained. We conclude that the biomechanical properties of the expanded skin are different from that of the unexpanded skin. But the biomechanical properties of conventional expanded skin are similar to that of rapid expanded skin. It is shown that the rapid expansion may be accepted in the practice.

The role of the local immune response in the pathogenesis of peptic ulcer formation

Mucosal immune responses are designed to provide local protection against infection, without inducing excessive amounts of inflammation that would alter epithelial integrity or function. It has become clear that the epithelium not only serves as a barrier to exclude pathogens, but also initiates host responses to infection. Gastric epithelial cells infected with Helicobacter pylori can respond within hours to produce inflammatory mediators that recruit and activate neutrophils. The gastric epithelium can also be recognized by local T-cells, resulting in their activation and ability to induce epithelial damage. During infection with H. pylori, there is a remarkable increase in the level of local IgG antibodies, which may also recognize and damage the epithelium. Thus, activated neutrophils, T-cells and auto-antibodies may contribute to a weakened epithelial barrier that allows luminal acid and other factors to contribute to peptic ulceration. The epithelium appears to play a key role in the initiation of the local inflammatory and immune responses that may contribute to the more serious sequelae associated with H. pylori infection.

Interferon-gamma increases cytoplasmic motility of alveolar macrophages via nitric oxide-dependent signaling pathways

The effects of interferon-gamma (IFN-gamma) were investigated on cytoplasmic motility of alveolar macrophages (AM) from rat lungs in vitro. Cytoplasmic motility was examined by measuring remnant field strength from the cell surface of AM containing Fe3O4 particles, and the relaxation rate (lambda 0; min-1), which is related to cytoplasmic motility, was determined. IFN-gamma caused an increase in lambda 0 in a concentration-dependent fashion with the maximal effect at 1,000 U. Dibutyryl cyclic GMP (db cyclic GMP; 10(-3) M) mimicked IFN-gamma-induced effects, but db cyclic AMP (10(-3) M) decreased lambda 0. IFN-gamma (1,000 U)-induced increases in lambda 0 were concentration-dependently inhibited by NG-monomethyl-L-arginine (L-NMMA) with complete inhibition of a concentration of 10(-4) M and were also completely inhibited by either methylene blue (10(-5) M) or KT 5823 (10(-5) M), a specific inhibitor of protein kinase G. IFN-gamma (1,000 U) caused significant nitrite (NO2-) production from the control values of 0.2 +/- 0.1 to 10.0 +/- 0.2 microM/24 h per 10(6) cells (P < 0.001, n = 10), and this increase in NO2- production by IFN-gamma (1,000 U) was completely inhibited by L-NMMA (10(-4) M). IFN-gamma caused a concentration-dependent increase in a filamentous-actin (F-actin) content with the maximal effect at 1,000 U. db cyclic GMP (10(-3) M) mimicked IFN-gamma induced effects on F-actin formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Ocular alpha 2-receptor subclasses and antiglaucoma efficacy

An overview of the ocular hypotensive actions of some alpha 2-agonists with imidazoline structures is presented. These agents inhibit isoproterenol-stimulated adenylate cyclase (AC) activity in ciliary process membrane through a Na+ and GTP-dependent mechanism. Receptor binding studies with the alpha 2-agonist radioligand [125I] p-iodoclonidine ([125I]PIC) in rabbit ciliary body membranes indicate that the alpha 2-receptor subtype is alpha 2A. Gpp(NH)p and NaCl dose-dependently decreased the number of [125I]PIC binding sites by shifting the receptor-G protein complexes from the high affinity state to the low affinity state for agonist binding. This is consistent with the observations that inhibition of AC was Na+ and GTP dependent. The NaCl and Gpp(NH)p effects on binding appeared to be through different mechanisms. The alpha 2-receptor in ciliary process thus appears to be an alpha 2A-receptor that is negatively coupled to the AC-cAMP generating system.

Capsaicin desensitization inhibits swallowing reflex in guinea pigs

To determine whether capsaicin-sensitive sensory nerves are involved in the swallowing reflex, we examined swallowing reflex in terms of the number of swallows elicited by injections of three different volumes (0.2, 0.4, and 0.6 ml) of distilled water, into the pharynx through a catheter in anesthetized guinea pigs pretreated with and without systemic capsaicin. The number of swallows was counted by submental electromyographic activity and visual observation of characteristic laryngeal movement. Injections of distilled water caused a volume-dependent increase in the number of swallows in animals treated with and without capsaicin. Capsaicin treatment significantly decreased the number of swallows elicited by all volumes of distilled water (p < 0.01). Exogenously administered substance P (SP) caused a dose-dependent increase in the number of swallows in all volumes but calcitonin gene-related peptide and acetylcholine were without effect. FK 888 (10(-5) M; 1 ml), a specific inhibitor of NK1 receptor, reduced the number of swallows elicited by distilled water to a similar degree as capsaicin treatment. Pharyngeal application of lidocaine (4%; 1 ml) also inhibited distilled water-induced swallowing. These results suggest that nonmyelinated C-fibers regulate the swallowing reflex through the release of SP in response to stimulation.

A statistical model of infant mortality

"We have developed here a statistical model for describing infant deaths. Even though the model is tested with Canadian data, it will be a good approximation of the relationship between infant deaths and age in any population. The model needs improvement when high risk populations are studied."

[External work of canine latissimus dorsi muscle after vascular delay]

The first purpose of this study was to estimate physiological performance of skeletal muscle for circulatory assist. External work in the form of linear dynamic contraction was studied in canine latissimus dorsi muscle (LDM). The second purpose was to relate the effect of vascular delay of the LDM to the physiological performance. The left LDM with vascular delay (VD) were compared to the right control LDM (CTR) without vascular delay. Simultaneous dynamic contraction of both VD and CTR LDM were studied under various settings of the preloads and the afterloads. Maximal external work per single contraction were 136 +/- 38 mJ in VD and 81 +/- 21 mJ in CTR. Maximal total work, which includes external work and preload work, were 578 +/- 195 mJ in VD and 407 +/- 146 mJ in CTR. Maximal fractional shortenings of the LDMs were 22.8 +/- 4.7% in VD and 17.5 +/- 2.6% in CTR. The maximal external work of VD was 81% of canine LV stroke work and 620% of canine RV stroke work. The maximal total work of VD was 340% of canine LV stroke work. The fractional shortenings, external work and total work of VD were higher than those of CTR under all loading conditions. The physiologic performance of canine LDM was improved after vascular delay.