Outcome of arthroscopic single-bundle anterior cruciate ligament reconstruction: anteromedial portal technique versus transtibial drilling technique.

PURPOSE: Controversies exist about the femoral tunnel preparation technique in anterior cruciate ligament (ACL) reconstruction surgeries. The aim of this study was to evaluate mid-term outcomes of transtibial (TT) technique in comparison with anteromedial portal (AMP) one. METHODS: Demographic data, height, weight, period of time from injury to surgery, and follow-up duration of patients underwent ACL reconstruction using single-bundle hamstring graft by the senior author between 2007 and 2011 were evaluated, retrospectively. Mid-quadriceps circumference difference, passive range of motion of the joint, anterior drawer test, Lachman test, and pivot shift test were assessed for each case. Function of the knee joint was calculated using International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores. RESULTS: Of 50 cases in the AMP group (age 30.6 ± 6.5), 45 were male and of the 44 patients in the TT group (age 30.0 ± 6.5), forty were male. Mean follow-up times in the AMP and TT group were 18.2 months (range 12-84 months) and 25.7 months (range 16-48 months), respectively. No statistically significant difference was found in mid-quadriceps circumference difference (P = 0.861). Also, functional knee scores (P values of IKDC = 0.329, Lysholm score = 0.08, Tegner = 0.504) and stability tests (P values of anterior drawer test = 0.07, Lachman test = 0.486, pivot shift test = 0.348) did not differ statistically between groups. CONCLUSION: There is no superiority of AMP technique on TT technique in ACL reconstructive surgeries. It could be suggested that performing a well-done technique, either TT or AMP, may be more important than only choosing a technique.

The healing effect of bioglue in articular cartilage defect of femoral condyle in experimental rabbit model.

BACKGROUND: The full-thickness articular cartilage defects of knee have a poor healing capacity that may progress to osteoarthritis and need a knee replacement. This study determines the healing effect of bioglue in fullthickness articular cartilage defect of femoral condyle in rabbit. METHODS: Forty-eight male rabbits were randomly divided into four equal groups. In group A, 4 mm articular cartilage defects were created in the right and left medial femoral condyles. Then a graft from xiphoid cartilage was transferred into the defect together with a designed bioglue and the knees were closed. In group B, an articular cartilage defect was created identical to group A, but the defect size was 6 mm. In group C, 4 and 6 mm articular cartilage defects were created in the right and left medial femoral condyles respectively. The graft was transferred into the defect and the knees were stitched. In group D, articular cartilage defects were created similar to group C, just filled with bioglue and closed. The rabbits were euthanized and subgroups were defined as A1, B1, C1 and D1 after 30 days and A2, B2, C2 and D2 after 60 days. The cartilages were macroscopically and histologically investigated for any changes. RESULTS: Microscopic and macroscopic investigations showed that bioglue had a significant healing effect in the femoral condyle. CONCLUSION: Addition of bioglue can effectively promote the healing of articular cartilage defects.

Mechanism of vasopressin-induced increase in intracellular Ca2+ in LLC-PK1 porcine kidney cells.

Analysis of the signal transduction cascade of vasopressin-induced increase in intracellular Ca2+ concentration ([Ca2+]i) in LLC-PK1 cells was performed. First, a comparison of the effect of vasopressin on [Ca2+]i in LLC-PK1 cells with that produced in rat hepatocytes was performed [an intracellular mobilizing mechanism involving a V1 receptor coupled to the production of inositol 1,4,5-trisphosphate (IP3)]. Second, the effect of known inhibitors of intracellular Ca2+ mobilization on vasopressin Ca2+ response in LLC-PK1 cells was studied. Vasopressin induced a transient increase in [Ca2+]i in both LLC-PK1 cells and hepatocytes. In contrast to the single [Ca2+]i spike seen in LLC-PK1 cells, vasopressin induced an average of two to three [Ca2+]i spikes in hepatocytes. The V1 antagonist (Pmp1-O-Me-Tyr2-[Arg8]vasopressin, 1 microM) abolished vasopressin Ca2+ response in both cell types. Inhibitors of intracellular Ca2+ mobilization, thapsigargin (5 microM) and U-73122 (3 microM), abolished the Ca2+ response by vasopressin in LLC-PK1 cells. The results suggest that vasopressin-induced increase in [Ca2+]i in LLC-PK1 cells is mediated via a V1-like receptor and involves the mobilization of intracellular Ca2+ through an IP3- or thapsigargin-sensitive Ca2+ pool.

GM1 ganglioside reduces ethanol intoxication and the development of ethanol dependence.

The monosialoganglioside, GM1, protects the nervous system against a variety of insults. In this study, we evaluated the protective properties of GM1 on ethanol intoxication and development of dependence. GM1 (20-40 mg/kg, IP) reduced the extent and duration of ataxia produced by ethanol (2 g/kg, IP, 15-95 min), and delayed the onset of loss and reduced the duration of the righting reflex (LORR) produced by ethanol (4.2 g/kg, IP). GM1 did not alter ethanol-induced hypothermia or the rate of ethanol clearance. Rather, GM1 increased the waking blood ethanol concentration. In animals fed a complete liquid diet containing 4.5% ethanol, concurrent administration of GM1 (40 mg/kg/day) blocked the tremors, hypolocomotion, and anxiety-like behavior associated with ethanol withdrawal. These findings demonstrate that GM1 reduces both ethanol's acute intoxication and the signs and symptoms of ethanol withdrawal by a mechanism not related to ethanol pharmacokinetics.

Sensitization to 5-HT1C receptor agonist in rats observed following withdrawal from chronic ethanol.

Anxiogenic action of m-chlorophenylpiperazine (mCPP), a 5-HT1C receptor agonist, was studied in naive rats and in ethanol-tolerant rats following withdrawal from chronic ethanol administration. The purpose of this investigation was to determine whether a sensitization to mCPP develops during withdrawal from chronic ethanol. Male Long-Evans hooded rats were fed a liquid diet containing 4.5% ethanol or dextrin (as control) for four days. Twelve hours (acute withdrawal) or 4 days (protracted withdrawal) after the last dose of ethanol, rats were injected with saline or mCPP (0.08-5.0 mg/kg) and were tested in the elevated plus-maze 15 min postinjection. A reduction in percent open-arm activity, indicative of anxiogenic behavior, was observed in ethanol-treated rats injected with saline. Administration of mCPP further reduced the percent open-arm entries and time in ethanol-withdrawn rats. An eightfold reduction in maximum effective dose of mCPP was observed during acute ethanol withdrawal as compared to that in naive rats. During protracted ethanol withdrawal the maximum effective dose of mCPP was reduced by 75%. A shift of the mCPP dose-response curve to the left following withdrawal from chronic ethanol may indicate that 5-HT1C receptor sites are more sensitive to the activation by an agonist. This effect may be exploited in developing specific 5-HT1C receptor antagonists for the treatment of ethanol withdrawal symptoms.

Potential role of 5HT1C and/or 5HT2 receptors in the mianserin-induced prevention of anxiogenic behaviors occurring during ethanol withdrawal.

A single dose of mianserin (a 5HT1C/5HT2 antagonist), administered 1 hr, 48 hr, or 7 days before testing, was evaluated for its efficacy in alleviating or preventing the occurrence of anxiogenic behaviors observed during ethanol withdrawal. Other behavioral experiments using selected drug interactions were conducted to examine whether the effect of mianserin was related to a long-term modification of 5-hydroxy-tryptamine (5HT) receptor function. Rats were fed a liquid diet containing 4.5% ethanol for 4 days. They were tested on the elevated plus-maze (EPM) 12 hr (acute withdrawal) and 5 days (protracted withdrawal) after the last ethanol dose. Ethanol withdrawal induced a pattern of "anxiogenic" behavior that consisted of reduced activity (total entries) and a reduced proportion of open arm activity. Mianserin, injected as a single dose given either 1 hr (0.16-5 mg/kg, ip) before testing or given (20 mg/kg, ip) on the morning of the 3rd day of ethanol administration, i.e., 48 hr and 7 days before testing, dose-dependently prevented or reversed the ethanol withdrawal induced reduction in open-arm activity. In contrast, the 5HT1C/5HT2 receptor agonist (+/- )-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl (DOl) did not affect behaviors in the EPM in ethanol-naive rats, nor in those undergoing ethanol withdrawal. However, although there was a marked tolerance to DOl-induced body shakes (a measure of 5HT2 function) during withdrawal, DOl reversed the action of mianserin in the EPM. The 5HT1 receptor agonist, 5HT2 receptor antagonist 1-naphthyl-piperazine (1-NP) reduced open-arm activity in ethanol-naive rats and this action was enhanced during withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

Conflicting evidence regarding the efficacy of ondansetron in benzodiazepine withdrawal.

These experiments tested the efficacy of the 5-hydroxytryptamine3 antagonist ondansetron (OND) in reversing various aspects of benzodiazepine withdrawal in rats. Three tests were used in which the benzodiazepine antagonist flumazenil was administered to rats receiving chronic administration of chlordiazepoxide. In one test, the elevated plus-maze, flumazenil produced a reduction in time spent in the open arms of the maze; OND completely reversed this effect of flumazenil in a dose-related fashion. However, OND failed to block the effects of the anxiogenic drug pentylenetetrazole (PTZ) in the elevated plus-maze. In a second test, rats were trained to discriminate PTZ. After chlordiazepoxide, flumazenil substituted for PTZ; OND failed to block flumazenil. In a third test, rats maintained on a chronic base line of chlordiazepoxide were trained to discriminate flumazenil from vehicle. In this discrimination, PTZ substituted for flumazenil, and pentobarbital blocked the flumazenil stimulus; OND, however, failed to block the flumazenil stimulus. In a separate set of experiments, OND also failed to reverse the suppression of responding produced in a conditioned emotional response paradigm. Thus, some data from the elevated plus-maze are consistent with the hypothesis that benzodiazepine withdrawal shares common effects with other stimuli known to be anxiogenic, and that OND blocks this aspect of withdrawal. However, all other data are inconsistent with the hypotheses that OND is anxiolytic or has efficacy in reversing benzodiazepine withdrawal. We suggest that ondansetron is likely to have minimal efficacy in humans for the treatment of sedative-hypnotic withdrawal.

Anxiogenic behavior in rats during acute and protracted ethanol withdrawal: reversal by buspirone.

This study investigated the effectiveness of buspirone in reversing the anxiogenic behaviors occurring during ethanol withdrawal as measured in the elevated plus-maze. In response to anxiogenic drugs, rats spend less time in and make fewer entries onto the open arms of an elevated plus-maze, whereas anxiolytic drugs produce opposite effects. In this study, rats were fed a liquid diet containing 4.5% ethanol for 7 days. Twelve h (acute withdrawal) and 7 days (protracted withdrawal) following cessation of the ethanol diet, rats were tested on the elevated plus-maze. During these withdrawal periods, the percent open-arm entries and time spent on the open arms were significantly reduced relative to animals fed an ethanol-free diet, suggestive of anxiogenic-like symptoms. Buspirone (0.32-1.25 mg/kg) dose dependently reversed the withdrawal-induced decreases in open-arm activity. The anxiolytic-like activity of buspirone observed during ethanol withdrawal may be due to a reduction in serotonergic neurotransmission through activation of presynaptic 5-HT1A autoreceptors. The results obtained in this study suggest that pharmacotherapy with selective 5-HT1A agonists may be beneficial in alleviation of anxiety during ethanol withdrawal.

Mianserin in the treatment of ethanol withdrawal in the rat: prevention of behaviors indicative of anxiety.

The present investigation was a pilot study to determine whether a single dose of mianserin, which produces long-term down-regulation of serotonin1C (5-HT1c) and 5-HT2 receptors, would prevent anxiogenic behaviors occurring during ethanol withdrawal as evaluated in the elevated plus maze. Male Long-Evans hooded rats were fed a liquid diet containing 4.5 percent ethanol for 4 days. Mianserin (20 mg/kg, i.p.) was injected on the morning of the third day of ethanol administration, or 48 hrs and 7 days prior to testing. When animals were tested either 12 hrs (acute withdrawal) or 5 days (protracted withdrawal) after the last dose of ethanol, anxiogenic behaviors were observed as a significant reduction in both percentage of open-arm entries and time spent on the open arms. In contrast, these anxiogenic behaviors were prevented by pre-injection with mianserin 48 hrs or 7 days prior to testing. Attenuation of this important symptom of ethanol withdrawal is of particular importance because, in addition to the nonaddicting properties of mianserin relative to current anxiolytics, the beneficial effects appear to be long lasting and can be achieved with a single dose.

Modulation of benzodiazepine agonist and inverse-agonist receptor binding by GABA during ethanol withdrawal.

1. The present study examined the capacity of GABA to modulate flunitrazepam and Ro15-4513 binding to putative GABAA receptors. Binding was measured in distinct brain regions both before and during selected periods of withdrawal from ethanol. 2. Rats were fed a nutritionally complete liquid ethanol (4.5% w/v) diet for 4 days and at various times after the last dose of ethanol (0, 12, 24, & 72 hr), rats were sacrificed and extensively washed brain membrane fractions were prepared. 3. Competitive inhibition of 3H-flunitrazepam binding by either flunitrazepam or Ro15-4513 (10(-10)M to 10(-7)M) was performed in the absence and presence of GABA (10(-5)M). In the presence of GABA, the apparent affinity for flunitrazepam was increased approximately 1.7 fold and the apparent affinity for Ro15-4513 was decreased by 1.7 fold. 4. No alteration in the capacity of GABA to modulate flunitrazepam or Ro15-4513 affinity (e.g. GABA-shift) was observed in cortical membrane preparations either 12 or 72 hr following ethanol cessation. 5. Further, no changes in GABA-modulation of flunitrazepam binding was evident 0, 12, 24, or 72 hr after the last ethanol dose in membranes prepared from cortex, hippocampus or cerebellum. 6. Therefore, results from the present study indicate that the capacity of GABA to modulate receptor affinity for benzodiazepine agonists and inverse-agonists in rat cortex, hippocampus or cerebellum is not altered during withdrawal from chronic ethanol.

Effects of inorganic mercury on [3H]dopamine release and calcium homeostasis in rat striatal synaptosomes.

Inorganic mercury (Hg2+) in vitro increases spontaneous transmitter release from nerve terminals. The mechanisms of action are not well understood but may involve alterations in intraterminal Ca2+ dynamics. In this study we describe actions of Hg2+ in vitro on isolated mammalian CNS striatal nerve terminals (synaptosomes). Cobalt (2 mM) completely blocked the effect of 2 microM Hg2+ on spontaneous [3H]dopamine release. Cadmium (100 microM) was equipotent to Co2+ in blocking depolarization-dependent [3H]dopamine release, but did not alter the 2 microM Hg2(+)-induced spontaneous [3H]dopamine release. Depolarization-dependent [3H]dopamine release was not altered by 5 microM Hg2+. It appears that the site of action of Hg2+ on spontaneous [3H]dopamine release is not the Ca2+ channel. The effects of Hg2+ on intraterminal ionized Ca2+ [( Ca2+]i) were evaluated using the Ca2(+)-specific fluorescent probe, fura-2. Hg2+ (1-8 microM) had no effect on [Ca2+]i in 1.2 mM Ca2(+)-containing buffers. In nominal Ca2+ media, 4 and 8 microM Hg2+ significantly decreased [Ca2+]i. Following exposure to 4 and 8 microM Hg2+ the quenching of extrasynaptosomal fura-2 by Mn2+ was increased, suggesting that Hg2+ facilitated the leakage of fura-2. This apparent leakage was probably due to a nonspecific increase in membrane permeability since 2 microM Hg2+ produced a Co2(+)-insensitive increase in [3H]deoxyglucose phosphate efflux. Hg2+ did not increase the leakage of either lactate dehydrogenase or soluble protein from synaptosomes. Hg2+ produced a concentration-dependent (1-8 microM) increase in 45Ca2+ efflux from superfused synaptosomes which was insensitive to blockade either by 2 mM Co2+ or by 100 microM Cd2+. These data suggest that the transmitter releasing action of Hg2+ involves interactions with sites that also interact with Co2+ but not with Cd2+. Furthermore, Hg2+ may have direct transmitter releasing actions (i.e., Ca2(+)-mimetic properties), as well as nonspecific actions on plasma membrane permeability which may not necessarily be linked to [3H]dopamine release.

Fura-2 measurement of cytosolic free calcium in rat brain cortical synaptosomes and the influence of ethanol.

The effects of ethanol on resting and KCl-depolarized cytosolic calcium concentrations ([Ca2+]i) were measured in purified rat cortical synaptosomes using the calcium indicator fura-2. Ethanol (500-700 mM) significantly elevated the resting [Ca2+]i by 13-25% in the presence of 100 microM external calcium. In the absence of external Ca2+, ethanol (50-200 mM) significantly increased [Ca2+]i by 17-23%. Ethanol (200-700 mM) also significantly decreased KCl-induced rise in [Ca2+]i (delta K) by 40-82% in fura-2 loaded preparations incubated in the absence or presence of external calcium. Ethanol did not produce a significant change in delta K at 50 and 100 mM concentrations. These results suggest that ethanol may cause an elevation in [Ca2+]i via mobilization of intracellular calcium stores which may be linked to a calcium-dependent inactivation of voltage-sensitive calcium channels.

Aging does not alter cytosolic calcium levels of cortical synaptosomes in Fischer 344 rats.

Several lines of experimental evidence support an association between altered Ca2+ regulation and aging. It has been supposed that free cytosolic Ca2+ concentrations ([Ca2+]i) may decrease or increase in aged animals. In this study, both resting and KCl-stimulated [Ca2+]i were measured in purified cortical synaptosomes from young (3 mo.), middle-aged (12 mo.), and old (24 mo.) Fischer 344 rats. Two additional groups of rats were included, one middle-aged and one old which were trained on a treadmill for 6 months prior to experimentation. The [Ca2+]i was determined using the fluorescent Ca2+ chelator fura-2. Net KCl-dependent changes (delta K) in [Ca2+]i were determined by the difference between stimulatory (100 microM Ca2+/60 mM KCl) and resting (100 microM Ca2+/5 mM KCl buffer) conditions among the 3 age groups. Significant increases in [Ca2+]i were observed in each age group upon depolarization with 60 mM KCl. However, there were no significant age-dependent differences in either resting [Ca2+]i or KCl-stimulated [Ca2+]i.

Differential sensitivity of synaptosomal calcium entry and endogenous dopamine release to omega-conotoxin.

The presynaptic neurotoxin omega-conotoxin (omega-CgTx) was tested for its ability to inhibit voltage-dependent calcium flux and transmitter release in rat brain synaptosomes. Conotoxin (0.001-10 microM) had no effect on calcium uptake or endogenous dopamine release from rat striatal synaptosomes in the absence of potassium depolarization. Fast-phase potassium stimulated calcium influx was only partially (20-30%) inhibited by conotoxin at concentrations between 1 nM and 10 microM. The fast-phase release of endogenous dopamine from the same synaptosomal preparation was inhibited by approximately 25% at 0.01 microM and by 60% at 10 microM. These results suggest that a subgroup of high affinity omega-CgTx-sensitive calcium channels may be involved in regulating the release of endogenous dopamine from brain synaptosomes.