All-inside anterior cruciate ligament reconstruction using semitendinosus tendon and soft threaded biodegradable interference screw fixation

A modification of anterior cruciate ligament (ACL) reconstruction using a minimally invasive and endoscopic all-inside technique is presented. Both the femoral and tibial socket are approached through the joint so that there is no open tibial tunnel, which otherwise often causes significant pain and discomfort during early rehabilitation. The autologous semitendinosus tendon is harvested with a bone plug attached to its tibial insertion. The triple-stranded semitendinosus tendon is looped around the adjacent bone plug and fixed at the original tibial attachment site of the ACL using a soft threaded biodegradable poly-(D,L-lactide) interference screw. The screw is inserted endoscopically in an inside-out direction. In the femoral socket the graft is fixed without a bone plug directly to the tunnel wall using the biodegradable screw. The free part of the graft is thus not longer than the intra-articular distance, which may increase stiffness of the construct.     

Pharmacokinetic-pharmacodynamic modeling of stimulatory and sedative effects of alprazolam: timing performance deficits

Alprazolam decreased the reinforcement rate and increased the shorter-response rate of contingency-controlled timing behavior under a differential reinforcement of low-rate schedule (DRL 45-s) in rats. An integrated pharmacokinetic-pharmacodynamic (PK-PD) model was developed to describe and characterize the effects of i.v. and s. c. administration of alprazolam. The onset, peak and disappearance of alprazolam effects were evaluated during a 3-hr session. After s. c. alprazolam administration, two peak increases in shorter-response rate occurred at moderate alprazolam serum levels, first in the ascending and then in the descending limb of the concentration-time profile. We used a stimulation-sedation PD model incorporating two opposing effect-link sigmoidal Emax functions to model the two peaks after s.c. alprazolam administration. The model suggested that alprazolam possesses both stimulatory and sedative effects in a continuous but sequential fashion, which corresponded to low- and high-concentration effects as indicated by the EC50 values of 0.09 and 0.18 microg/ml, respectively. Owing to the rapid onset of i.v. administration, the first peak (a transition phase before the onset of the sedative effect) was absent, with the presence of the second peak again coinciding with the offset of the sedative effect. The reinforcement rate (IC50 = 0.02 microg/ml) characterized by the indirect response model to account for the initial hysteresis is an index for evaluating the deficit in timing performance. Although the effects of alprazolam can be described in behavioral terms, simultaneous PK-PD optimization numerically defines the performance and hypothesizes the coexistence of stimulation and sedation components for alprazolam. The stimulation-sedation model may help in delineating the possible mechanisms for adverse rebound side effects and of tolerance in humans.     

Sources of variability in data from a positive selection lacZ transgenic mouse mutation assay: an interlaboratory study

Experimental features of a positive selection transgenic mouse mutation assay based on a lambda lacZ transgene are considered in detail, with emphasis on results using germ cells as the target tissue. Sources of variability in the experimental protocol that can affect the statistical nature of the observations are examined, with the goal of identifying sources of excess variation in the observed mutant frequencies. The sources include plate-to-plate (within packages), package-to-package (within animals), and animal-to-animal variability. Data from five laboratories are evaluated in detail. Results suggest only scattered patterns of excess variability below the animal-to-animal level, but, generally, significant excess variability at the animal-to-animal level. Using source of variability analyses to guide the choice of statistical methods, control-vs-treatment comparisons are performed for assessing the male germ cell mutagenicity of ethylnitrosourea (ENU), isopropyl methanesulfonate (iPMS), and methyl methanesulfonate (MMS). Results on male germ cell mutagenesis of ethyl methanesulfonate (EMS) and methylnitrosourea (MNU) are also reported.     

Ancient schwannoma masquerading as parotid pleomorphic adenoma

BACKGROUND: The relationship between severe reactive airway disease (RAD) and gastroesophageal reflux disease (GERD) has been noted but the relationship is poorly understood. This study reports our experience with laparoscopic fundoplication and its effect on the pulmonary status of children with severe steroid-dependent reactive airway disease. METHODS: Fifty-six patients with severe steroid-dependent RAD and medically refractory GERD underwent laparoscopic Nissen fundoplications. Mean age was 7 years and mean weight was 20 kg. All patients had the procedure completed successfully laparoscopically with an average operative time of 62 min. Average hospital stay was 1.6 days. RESULTS: Forty-eight of 56 patients noted significant improvement in their respiratory symptoms in the first week. Fifty of 56 patients have been weaned off their oral steroids and four others have had a greater than 50% decrease in their dose. Sixteen patients had a documented increase in their FEV1 in the initial postoperative period (avg. 26%). CONCLUSION: Patients with steroid-dependent RAD and GERD refractory to medical management show improvement in their respiratory status following fundoplication and the majority can be weaned off of their oral steroids. Laparoscopic techniques allow this procedure to be performed safely even in this high-risk group of patients.     

The effect of female age and ovarian reserve on pregnancy rate in male infertility: treatment of azoospermia with sperm retrieval and intracytoplasmic sperm injection

Factors other than spermatozoa could be the major determinant of the success of assisted reproduction treatment in cases of male infertility. Our aim was to evaluate the effect of the wife's age and ovarian reserve on assisted reproduction success rates in the most severe type of male infertility, i.e. azoospermia. A total of 249 consecutive couples suffering from male infertility caused by azoospermia underwent microsurgical epididymal sperm aspiration (MESA) or testicular sperm extraction (TESE) with intracytoplasmic sperm injection (ICSI). Of these men, 186 had irreparable obstructive azoospermia, and 63 had non-obstructive azoospermia due to testicular failure. Neither the pathology, the source, the quantity, nor the quality of spermatozoa had any effect on fertilization or pregnancy rates. Maternal age and ovarian reserve (number of eggs) had no effect on fertilization or embryo cleavage, but did dramatically affect the embryo implantation, pregnancy and delivery rates. Wives of azoospermic men who were in their 20s had a 46% live delivery rate per cycle, wives aged 30-36 years had a 34% live delivery rate per cycle, wives aged 37-39 years had a 13% live delivery rate per cycle, and wives > or = 40 years had only a 4% live delivery rate per cycle. The number of eggs retrieved also affected pregnancy and delivery rate, but to a lesser extent than age. In virtually all cases of obstructive azoospermia, and in 62% of cases with non-obstructive azoospermia caused by germinal failure, sufficient spermatozoa could be retrieved to perform ICSI, with normal fertilization and embryo cleavage. However, the pregnancy rate and the live delivery rate were dependent strictly on the age of the wife, and on her ovarian reserve. Unfortunately, exaggerated claims of high pregnancy rates can thus easily be made by manipulating, in a very simple way, selection for female factors.     

Analysis of tumor-infiltrating lymphocytes in cutaneous squamous cell carcinoma

OBJECTIVE: To characterize tumor-infiltrating lymphocytes (TILs) within lesions of cutaneous squamous cell carcinoma (SCC) and related disorders. DESIGN: Case series with 1- and 2-color immunohistologic, molecular biological analysis of T-cell clonality and in vitro cytotoxicity assays. SETTING: Academic medical center. PATIENTS: Twenty-one patients, including 6 with actinic keratoses, 4 with SCC in situ, and 11 with invasive SCC. RESULTS: CD8+ TILs were present within lesions of cutaneous SCC and AK. These cells constituted a variable minority of the total T-cell infiltrate, and many expressed a phenotype consistent with major histocompatibility complex-restricted cytotoxic T lymphocytes: CD3+, TIA1+, CD16-, CD56-, CD57-. They also expressed HLA-DR, suggesting their activation in vivo. Virtually all T cells were T-cell receptor (TCR)-beta + delta, indicating that they expressed the TCR-alpha beta protein heterodimer. Molecular biological analysis of TCR-gamma gene rearrangements by the polymerase chain reaction and denaturing gradient gel electrophoresis technique indicated that the TILs were polyclonal. Functional studies suggested that TILs derived from SCC lesions were cytotoxic for autologous tumor cell targets. CONCLUSION: Tumor-infiltrating lymphocytes within cutaneous SCC lesions contain a subpopulation of polyclonal, major histocompatibility complex-restricted cytotoxic T lymphocytes expressing the TCR-alpha beta heterodimer.     

Ionic mechanisms of the effect of adenosine on single rabbit atrioventricular node myocytes

The ionic mechanisms underlying the negative dromotropic effect of adenosine were studied in calcium-tolerant myocytes isolated from the region of the rabbit atrioventricular (AV) node. Action potentials and membrane currents were recorded by using the whole cell patch clamp technique. Adenosine (1 to 50 microM) abolished the spontaneous activity of AV node myocytes with hyperpolarization of the membrane potential. Voltage clamp experiments showed that adenosine induced an inwardly rectifying, time-independent potassium current. These effects were antagonized by 8-cyclopentyl-1,3-dipropylxanthine and produced by ribose 5-phosphate isomerase A, indicating that they were mediated by the A1 adenosine receptor. Adenosine also had a small direct inhibitory action on the inward calcium current (ICa) but had a more marked indirect action following stimulation of the calcium current by isoprenaline. The isoprenaline-induced increase in ICa was abolished in the presence of adenosine 10 microM. In cells pretreated with the nitric oxide synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME), the isoprenaline-induced increase in ICa was not reduced by the addition of adenosine. Coincubation of the cells with L-NAME plus L-arginine (the endogenous substrate of nitric oxide synthase) restored the adenosine-induced attenuation of ICa. A membrane permeable analogue of cGMP, 8Br cGMP, an inhibitor of cGMP-stimulated phosphodiesterase, prevented the antiadrenergic effect of adenosine. These results suggest that adenosine activates guanylyl cyclase following the production of nitric oxide, and the subsequent stimulation of phosphodiesterase enhances the breakdown of isoprenaline-elevated cAMP leading to a reduction in the stimulated ICa. In conclusion, the important ionic mechanisms of the actions of adenosine on AV nodal cells are a direct effect, with activation of a potassium conductance and an indirect antiadrenergic effect on ICa, which is mediated by nitric oxide production and phosphodiesterase stimulation.     

Regulation of ciprofloxacin uptake in human promyelocytic leukemia cells and polymorphonuclear leukocytes

BACKGROUND: It has recently been shown that humoral antigastric autoreactivities occur in a substantial number of Helicobacter pylori infected patients. AIMS: To analyse the relevance of such antigastric autoantibodies for histological and serological parameters of the infection as well as for the clinical course. METHODS: Gastric biopsy samples and sera from 126 patients with upper abdominal complaints were investigated for evidence of H pylori infection using histology and serology. Autoantibodies against epitopes in human gastric mucosa were detected by immunohistochemical techniques. Histological and clinical findings of all patients were then correlated with the detection of antigastric autoantibodies. RESULTS: H pylori infection was significantly associated with antigastric autoantibodies reactive with the luminal membrane of the foveolar epithelium and with canalicular structures within parietal cells. The presence of the latter autoantibodies was significantly correlated with the severity of body gastritis, gastric mucosa atrophy, elevated fasting gastrin concentrations, and a decreased ratio of serum pepsinogen I:II. Furthermore the presence of anticanalicular autoantibodies was associated with a greater than twofold reduced prevalence for duodenal ulcer. CONCLUSION: The data indicate that antigastric autoantibodies play a role in the pathogenesis and outcome of H pylori gastritis, in particular in the development of gastric mucosal atrophy.