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A case of spontaneous recurrent haemarthrosis of the knee presenting 3 months after the unicondylar knee replacement is described. Femoral arteriography demonstrated hypertrophy of the saphenous branch of descending genicular artery with a prominent vascular blush in the region of posteromedial aspect of the popliteal fossa thought to represent a hypertrophic vascular mass of synovium. Therapeutic embolisation of the saphenous branch of descending genicular artery was performed using three fibred platinum coils with satisfactory clinical results. Since the embolisation, the haemarthrosis has not recurred. To our knowledge, this therapeutic procedure used to treat recurrent haemarthrosis following unicondylar knee arthroplasty has not been previously described in the literature.

5-HT3 (5-hydroxytryptamine type 3) receptors are cation-selective ion channels of the Cys-loop transmitter-gated ion channel superfamily. Two 5-HT3 receptor subunits, 5-HT3A and 5-HT3B, have been characterized in detail, although additional putative 5-HT3 subunit genes (HTR3C, HTR3D and HTR3E) have recently been reported. 5-HT3 receptors function as homopentameric assemblies of the 5-HT3 subunit, or heteropentamers of 5-HT3A and 5-HT3B subunits of unknown stoichiometry. The single-channel conductances of human recombinant homomeric and heteromeric 5-HT3 receptors are markedly different, being <1 and approx. 16 pS respectively. Paradoxically, from the results of studies performed on the closely related nicotinic acetylcholine receptor, the channel-lining M2 domain of the 5-HT3A subunit is predicted to enhance cation conduction, whereas that of the 5-HT3B subunit would not. The present study describes a novel determinant of single-channel conductance, out with the M2 domain, which accounts for this anomaly. Utilizing a panel of chimaeric 5-HT3A and 5-HT3B subunits, a profound determinant of single-channel conductance was traced to a putative amphipathic helix (the 'HA stretch') within the large cytoplasmic loop of the receptor. Replacement of three arginine residues (R432, R436 and R440) unique to the HA stretch of the 5-HT3A subunit with the aligned residues (Q395, D399 and A403) of the 5-HT3B subunit increased the single-channel conductance 28-fold. Significantly, from ultrastructural studies of the Torpedo nicotinic acetylcholine receptor, the key residues may be components of narrow openings within the inner vestibule of the channel, located in the cytoplasm, which contribute to the permeation pathway. Our findings indicate an important and hitherto unappreciated function for the HA stretch in the Cys-loop family of transmitter-gated ion channels., (Copyright 2004 Biochemical Society)

Reconstruction of a congenital hand anomaly in a child using single free vascularised transfer of the proximal interphalangeal joint of a second toe with the simultaneous microvascular reconstruction of the donor toe using the stiff joint and its dorsal skin paddle from the hand is described. This is not the first reported case of a toe-finger switch, but it is the first in a free joint transfer, for which it is especially indicated.

Background: The discriminative stimulus effects of ethanol are mediated in part by the gamma-aminobutyric acid type A (GABA(A)) receptor system. We have previously shown that microinjections of the competitive GABA(A) agonist muscimol in the nucleus accumbens and amygdala fully substitute for the discriminative stimulus effects of systemic ethanol. However, it is not known whether allosteric binding sites on GABA(A) receptors located within specific limbic brain regions contribute to the discriminative stimulus effects of ethanol., Methods: Male Long-Evans rats were trained to discriminate between intraperitoneal injections of ethanol (1 g/kg) and saline under a fixed-ratio 10 schedule of sucrose (10% w/v) reinforcement. Injector guide cannulae, aimed at both the nucleus accumbens core and the hippocampus area CA1, were then implanted to allow site-specific infusion of GABA(A)-positive modulators., Results: Infusion of the neurosteroid 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone, or 3alpha-5alpha-P) in the nucleus accumbens resulted in dose-dependent full substitution for intraperitoneal ethanol (50% effective dose = 0.38 ng/microl per side). Likewise, injection of the barbiturate pentobarbital into the nucleus accumbens also substituted dose-dependently for ethanol (50% effective dose = 1.55 microg/microl per side). However, infusions of either 3alpha-5alpha-P or pentobarbital in the hippocampus failed to substitute for ethanol and produced inverted U-shaped dose-response curves., Conclusions: These results demonstrate that allosteric positive modulation of GABA(A) receptors in the nucleus accumbens produces full substitution for the stimulus effects of ethanol. This suggests that GABA(A) receptors in the nucleus accumbens may play a more influential role in the discriminative stimulus effects of ethanol than those in the hippocampus.

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were R. Adron Harris and Susumu Ueno. The presentations were (1) Protein kinase Cepsilon-regulated sensitivity of gamma-aminobutyric acid type A (GABAA) receptors to allosteric agonists, by Robert O. Messing, A. M. Sanchez-Perez, C. W. Hodge, T. McMahon, D. Wang, K. K. Mehmert, S. P. Kelley, A. Haywood, and M. F. Olive; (2) Genetic and functional analysis of a GABAA receptor gamma2 subunit variant: A candidate for quantitative trait loci involved in alcohol sensitivity and withdrawal, by Kari J. Buck and Heather M. Hood; (3) Tryptophan-scanning mutagenesis in GABAA receptor subunits: Channel gating and alcohol actions, by Susumu Ueno; and (4) Can a single binding site account for actions of alcohols on GABAA and glycine receptors? by R. Adron Harris, Yuri Blednov, Geoffrey Findlay, and Maria Paola Mascia.

Rationale: The neurobiological systems that mediate the discriminative stimulus effects of self-administered drugs are largely unknown. The present study examined the discriminative stimulus effects of self-administered ethanol., Methods: Rats were trained to discriminate ethanol (1 g/kg, IP) from saline on a two-lever drug discrimination task with sucrose (10% w/v) reinforcement. Test sessions were conducted with ethanol (0 or 10% v/v) added to the sucrose reinforcement to determine if self-administered ethanol would interact with the discriminative stimulus effects of investigator-administered ethanol, or with the ethanol-like discriminative stimulus effects of the GABAA-positive modulator pentobarbital or the non-competitive NMDA antagonist MK-801., Results: During a saline test session, ethanol (10% v/v) was added to the sucrose reinforcement. Responding by all animals began accurately on the saline-appropriate lever and then switched to the ethanol-appropriate lever after rats self-administered a mean dose of 1.2 +/- 0.14 g/kg ethanol. During cumulative self-administration trials, responding initially occurred on the saline lever and then switched to the ethanol-appropriate lever after ethanol (0.68 +/- 0.13 g/kg) was self-administered. Investigator-administered MK-801 (0.01-1.0 mg/kg, cumulative IP) and pentobarbital (0.3-10.0 mg/kg, cumulative IP) dose-dependently substituted for ethanol. When ethanol (10% v/v) was added to the sucrose reinforcer, MK-801 and pentobarbital dose-response curves were shifted significantly to the left., Conclusions: Self-administered ethanol substituted for and potentiated the stimulus effects of investigator-administered ethanol, suggesting that the discriminative stimulus effects of self-administered ethanol are similar to those produced by investigator-administered ethanol. Self-administered ethanol enhanced the ethanol-like discriminative stimulus effects of MK-801 and pentobarbital, which suggests that the discriminative stimulus effects of self-administered ethanol are mediated by NMDA and GABAA receptors.

Several of the actions of ethanol are mediated by gamma-aminobutyrate type A (GABA(A)) receptors. Here we demonstrated that mutant mice lacking protein kinase C epsilon (PKCepsilon) were more sensitive than wild-type littermates to the acute behavioral effects of ethanol and other drugs that allosterically activate GABA(A) receptors. GABA(A) receptors in membranes isolated from the frontal cortex of PKCepsilon null mice were also supersensitive to allosteric activation by ethanol and flunitrazepam. In addition, these mutant mice showed markedly reduced ethanol self-administration. These findings indicate that inhibition of PKCepsilon increases sensitivity of GABA(A) receptors to ethanol and allosteric modulators. Pharmacological agents that inhibit PKCepsilon may be useful for treatment of alcoholism and may provide a non-sedating alternative for enhancing GABA(A) receptor function to treat other disorders such as anxiety and epilepsy.

Our previous work has documented that physical or psychological stress can alter interleukin (IL)-2, IL-4, and interferon (IFN)-gamma production by spleen or lymph node cells in vitro. To determine if adrenal hormones might be mediating these stress-induced changes in type 1 and type 2 cytokines and immune effector functions, we cultured spleen cells in vitro with either the synthetic glucocorticoid dexamethasone (DEX) or the putative restorative hormone dehydroepiandrosterone (DHEA). Spleen cells were obtained from either young (5-6 weeks old) or mature (7-8 months old) BALB/c mice that were either unimmunized or immunized with the T-cell-dependent antigen keyhole limpet hemocyanin (KLH). We determined that DEX suppressed production of all three cytokines examined. DHEA was not associated with any enhancement of cytokine production. These data challenge the hypothesis that glucocorticoids can differentially regulate Th1-like versus Th2-like cytokine production. Further, they suggest that in stress paradigms in which differential regulation of cytokine production and effector function has been observed, other neuroendocrine factors in addition to glucocorticoids must be relevant.

Widespread basalts and rhyolites were erupted in Madagascar during the Late Cretaceous. These are considered to be related to the Marion hot spot and the breakup of Madagascar and Greater India. Seventeen argon-40/argon-39 age determinations reveal that volcanic rocks and dikes from the 1500-kilometer-long rifted eastern margin of Madagascar were emplaced rapidly (mean age = 87.6 +/- 0.6 million years ago) and that the entire duration of Cretaceous volcanism on the island was no more than 6 million years. The evidence suggests that the thick lava pile at Volcan de l'Androy in the south of the island marks the focal point of the Marion hot spot at approximately 88 million years ago and that this mantle plume was instrumental in causing continental breakup.

The induction of sister chromatid exchanges (SCE) by the hepatocarcinogen methapyrilene hydrochloride was investigated using appropriate in vitro and in vivo mammalian cell systems. Methapyrilene, even at the maximum tolerated dose, did not induce SCE in Chinese hamster ovary cells (CHO) or when CHO cells or hamster lung fibroblasts, V-79, were cocultivated with early cultures of rat liver epithelial cells, which are known to metabolize different classes of chemical carcinogens to active forms. Moreover, a hybrid clone of cells (formed by fusion of CHO cells with rat liver epithelial cells), which is highly sensitive to SCE formation by a number of xenobiotics, failed to produce SCE after treatment with methapyrilene. Experiments in vivo with bone marrow cells and in vitro with CHO cells cocultivated with primary hepatocytes from rats also confirmed the inability of methapyrilene to induce SCE in the indicator cells. Since aflatoxin B1 induced SCE in the in vitro and in vivo models, it may be concluded that methapyrilene does not induce SCE at a concentration which is not cytotoxic to the indicator cells in the different systems described. Autoradiographic studies in cultured rat liver cells with tritiated methapyrilene showed that the label was localized in the cytoplasm but not in the interphase nuclei or in the metaphase chromosomes, indicating a lack of interaction of methapyrilene with the nuclear macromolecules of the putative target cells for methapyrilene.

We have tested the hypothesis that urocanic acid is the photoreceptor molecule for ultraviolet radiation-induced systemic suppression of contact hypersensitivity in the mouse. Almost complete removal of urocanic acid by tape-stripping of exposed skin was not associated with abrogation of immune suppression. This finding makes it unlikely that urocanic acid is the chromophore.

Although methapyrilene (MP) produces hepatocellular carcinomas in rats, it does not elicit many of the cellular responses induced by other hepatocarcinogens. We have investigated the early changes induced in rat liver epithelial cell cultures by MP using morphological, cytochemical, and cytofluorometric techniques. Within 2 h of MP treatment, inclusion bodies which were stainable with lipid stains were observed in the cytoplasm. Ultrastructurally, they resembled lamellar bodies with alternating light and dark lamellae. These bodies were transient in nature, since they disappeared within 24 h of removal of MP. They were, however, retained in the cytoplasm as long as MP was present in the medium. Lamellar bodies appear to be induced in the presence of histamine H1 receptor-blocking agents, since methaphenilene and diphenhydramine produced this reaction, but cimetidine, an H2 antagonist, did not. Morphologically, mitochondria of control cells were long and rod-like, whereas they were short or bizarrely shaped in the MP-treated cells. Moreover, a quantitative increase was observed in the mitochondrial content of the treated cells, when intact liver cells vitally stained with Rhodamine 123 were analyzed with a fluorescence-activated cell sorter. A significant increase in binucleated cells was observed when liver cells were exposed for 10 to 12 days with MP. Collectively, these results suggest that MP might perturb the cytoskeletal elements leading to an alteration in the nuclear and mitochondrial makeup of rat liver cells.

A number of liver epithelial cell cultures were established from 10 to 12-d-old sucklings, 6 to 8-wk-old young adults, or from 2 to 18-month-old partially hepatectomized rats. Improvements in the methods for cell isolation and culture yielded replicating cells from every experiment and they were maintained for different periods with regular passages. The proliferative potential in vitro of adult rat liver cells could be increased if the rats were subjected to partial hepatectomy before cell isolation. In the early passages, the majority of the cells were found to have a true diploid karyotype as studied by the Giemsa-banding technique. Under the culture conditions described, a very high percentage of cells remained in the diploid range for, in most cases, at least 4 months and in some cases for up to 6 months. Afterward, the karyotype was unstable, but no "crisis" period was seen before the cells became aneuploid. Until this time, the growth characteristics of the cells also followed a normal pattern showing density dependent inhibition of division and a lack of markers associated with malignancy. The cultured liver cells exhibited a number of liver specific properties when they were maintained as a confluent monolayer. The early passages of diploid epithelial cell cultures derived from normal and regenerating rat liver are good models for studies of the regulation of cell division and the changes that are related to carcinogenesis.

Repeated exposure of female C3H/HeNCR- mice to sunlight prevented the normal immunologic rejection of a UV-induced tumor. This systemic immunologic alteration was transferred to syngeneic lethally X-irradiated animals with lymphoid cells from mice exposed to sunlight. The lymphoid cells also were able to suppress the capacity of lymphoid cells from normal animals to reject a UV-induced tumor. The 295- to 320-nm wave band appeared to be responsible for this immunosuppressive effect of sunlight because suppression was prevented by filtration of the radiation through Mylar and by application of a sunscreen containing para-aminobenzoic acid. These observations may have importance in understanding the pathogenesis of sunlight-induced skin cancer in humans.