Proliferative osteoarthritis and osteoarthrosis in 15 snakes

Fifteen snakes representing seven species with segmental, proliferative osteoarthritis and osteoarthrosis of the spine were presented for examination. All the snakes were captive, privately owned, and fed domestic rodents. Physical examination, radiography, blood culture, bone culture, necropsy, and histopathology were performed on each snake. All the snakes had similar physical examination, radiologic, and necropsy findings. There were three histologic types of lesions: active bacterial osteoarthritis, predominantly noninflammatory osteoarthrosis with multifocal inflammation suggestive of chronic bacterial osteoarthritis, and noninflammatory lesions consistent with osteoarthrosis without evidence of inflammation or bacteria. These findings suggest that all these snakes represent a single disease process, bacterial infection of the vertebrae. The different histologic lesions observed in these snakes may be a continuum of lesions, from acute to chronic. Gram-negative bacteria were isolated from the blood or bone lesions of 8 of the 15 snakes. In six of these eight snakes, Salmonella species were isolated. Gram-positive bacteria (Streptococcus sp.) were isolated from two other snakes. Blood and bone culture results were well correlated, so blood culture may be effective for detecting active bacterial osteoarthritis.

Can local anesthesia be recommended for routine use in elective knee arthroscopy? A comparison between local, spinal, and general anesthesia

Local anesthesia (LA) for outpatient knee arthroscopy is not a standard procedure at most hospitals. To evaluate the LA technique for knee arthroscopy on medically healthy patients, this study compared 3 anesthesia techniques. Four hundred patients were randomized to either local (n = 200), general (n = 100), or spinal (n = 100) anesthesia. Evaluated outcomes included the patient's subjective view of the procedure, and nausea and pain at rest and during active movement. All variables were recorded perioperatively and postoperatively. In addition, the performing surgeon's opinion of the degree of patient pain and the technical difficulty of the procedure were noted. Three hundred forty-two patients completed the study. In the group receiving local anesthesia (n = 180) the median visual analog scale pain score during surgery was 6 mm (mean, 17.5; SD, 23.2; range, 0 to 100 mm). Twenty-one LA patients would have preferred another form of anesthesia. In 29 patients, LA was not considered as the optimal anesthesia by the performing surgeon. Eight LA patients agreed with the surgeon that the anesthesia method used was not optimal, of these patients, 5 had synovitis (3%). In 5% of the LA patients there were technical problems. Thus, this study shows that elective knee arthroscopy can be performed under local anesthesia in 92% of the patients from a technical point of view. Excluding patients who do not choose local anesthesia and those who have hypertrophic synovitis preoperatively, knee arthroscopies can be performed as safely and effectively under local anesthesia as under any other form of anesthesia. For most patients, local anesthesia can be recommended as the standard procedure for outpatient knee arthroscopy.

Phase I trial of intravenous thymidine and carboplatin in patients with advanced cancer

PURPOSE

To evaluate the biologic interactions and toxicities of carboplatin combined with a 24-hour infusion of thymidine 75 mg/m(2) in a phase I trial.

PATIENTS AND METHODS

Thirty-two patients with cancer refractory to conventional therapy were treated. The first set of patients (n = 7) received thymidine alone 4 weeks before subsequent planned courses of thymidine combined with carboplatin followed (4 weeks) by carboplatin alone. Carboplatin was administered over 20 minutes at hour 20 of the 24-hour thymidine infusion. The carboplatin dose was escalated in patient groups: 200 mg/m(2) (n = 3); 300 mg/m(2) (n = 7); 350 mg/m(2) (n = 4); 400 mg/m(2) (n = 3); 480 mg/m(2) (n = 10); and 576 mg/m(2) (n = 5). At the maximum-tolerated dose (480 mg/m(2)), five patients received combined therapy first and carboplatin alone second, and five patients received carboplatin first and combined therapy second. Maintenance therapy for stable or responding patients was combined therapy.

RESULTS

Evaluation demonstrated a trend toward thymidine protection of carboplatin-induced treatment-limiting thrombocytopenia. Neutropenia with carboplatin alone or in combination was negligible. Thymidine alone had no myelosuppressive effects and produced reversible grade 1 or 2 nausea and vomiting (57%), headache (25%), and grade 1 neurotoxicity (22%). Thymidine did not enhance expected carboplatin toxicities. There was no therapy-related infection or bleeding. Analysis of platinum in plasma ultrafiltrate and urine showed no effect by thymidine. Similarly, thymidine pharmacokinetics was not affected by carboplatin. As predicted, nicotinamide adenine dinucleotide levels in peripheral lymphocytes were increased during exposure to carboplatin and/or thymidine but were decreased by carboplatin alone. In three patients with high-grade glioma, responses included one complete remission (21 months) and one partial remission (14 months) at the 480-mg/m(2)-dose level, and disease stabilization (7 months) at the 400-mg/m(2-dose) level. A minor response was observed in a patient with metastatic colon cancer (5 months) at the 480-mg/m(2)-dose level.

CONCLUSION

The combination of carboplatin and thymidine as described is well tolerated. The data presented have resulted in a phase II study by the North American Brain Tumor Consortium.

Antioxidant status of children with steroid-sensitive nephrotic syndrome

Eighteen children with steroid-sensitive nephrotic syndrome (SSNS) were studied. The control group comprised 20 healthy children. The following indirect parameters of reactive oxygen species activity were determined in nephrotic patients during four stages of the disease (full relapse before prednisone administration, disappearance of proteinuria, prednisone cessation, unmaintained remission): plasma malondialdehyde (MDA) levels, copper/zinc superoxide dismutase (CuZn SOD) activity and glutathione peroxidase (GPX) activity in erythrocytes, reduced glutathione (GSH) and vitamin C levels in whole blood, and vitamin E level in serum. Increased MDA levels, reduced vitamin C levels, and enhanced CuZn SOD activity were found in relapse. GSH concentration was high during all four stages. Vitamin E level was also increased, parallel to the pattern of serum lipids. GPX activity remained low during the proteinuria stage and in remission. We conclude that the majority of abnormal findings can be attributed to the hyperlipidemia of NS. Low GPX activity may be a factor limiting the antioxidant capacity in NS. The present study is inconclusive regarding the role of free radicals in the proteinuria of NS.

The acquired Chiari malformation and syringomyelia following spinal CSF drainage: a study of incidence and management

Firstly, 14 patients are described who developed either an acquired Chiari malformation (ACM) alone (7 cases) or ACM and syringomyelia (7 cases) after lumbar subarachnoid space (SAS) shunting or in one case, epidural anaesthesia with SAS penetration. Four groups are considered: 3 cases with craniofacial dysostosis and communicating hydrocephalus (CH), 4 cases with CH alone, 3 cases with pseudotumour cerebri (PTC) and a miscellaneous group (4 cases). Initial treatment was varied: resiting the shunt to ventricle or cisterna magna [6], adding an H-V valve [1], syrinx shunting [4] and posterior fossa decompression [3]. Further treatment was required in 6 cases. Secondly, incidence was examined in 87 patients with PTC initially treated either by lumbar SAS shunting [70] or cisterna magna shunting [17]. In the first sub-group, 11 cases (15.7 per cent) developed an ACM, 3 symptomatic (as above) and eight asymptomatic with 1 case also having syringomyelia whereas 1 case occurred in the second group with a questionanably symptomatic ACM. While accurate for symptomatic lesions, these figures are tentative with respect to asymptomatic lesions due to inadequate pre-treatment radiology and detailed MR follow-up. The main conclusions are, first, that the incidence of symptomatic ACM and/or syringomyelia is not high enough to warrant abandoning SAS shunting; second that asymptomatic lesions need not necessarily be treated and third, that when treatment is required, shunt resiting is the first choice.

Characterization of prostate-specific antigen proteolytic activity on its major physiological substrate, the sperm motility inhibitor precursor/semenogelin I

The protease prostate-specific antigen (PSA) is a marker widely used clinically for monitoring prostatic malignancies. Under normal conditions, this enzyme is mainly involved in the post ejaculation degradation of the major human seminal protein, the seminal plasma motility inhibitor precursor/semenogelin I (SPMIP/SgI), which is the predominant protein component of human semen coagulum. PSA primary structure and activity on synthetic substrates predict a chymotrypsin-like activity whose specificity remains to be established. The present study was aimed at characterizing the proteolytic processing of the SPMIP/SgI by PSA. Purified SPMIP/SgI was incubated with PSA in the presence or absence of protease inhibitors. General serine protease inhibitors, heavy metal cations (Zn2+ and Hg2+), and the heavy metal chelator 1,10-phenanthroline partially or totally inhibited the proteolytic activity of PSA toward SPMIP/SgI. Under identical conditions, other proteins, such as bovine serum albumin, ovalbumin, and casein, were very poor substrates for PSA. Hydrolysis products were separated by reverse-phase high-performance liquid chromatography, assayed for sperm motility inhibitory activity, and analyzed by immunoblotting and mass spectrometry. The region responsible for the sperm motility inhibitory activity and containing an SPMI antiserum epitope was localized to the N-terminal portion of the molecule between residues 85 and 136. On the other hand, a monoclonal antibody against a seminal vesicle-specific antigen (MHS-5) recognized fragments derived from the central part of the SPMIP/SgI (residues 198-223). PSA hydrolysis occurred almost exclusively at either leucine or tyrosine residues, demonstrating directly for the first time a restricted chymotrypsin-like activity on a physiological substrate. The results suggest that PSA is the main enzyme responsible for the processing of SPMIP/SgI in human semen and that this protease manifests unusual specificity with respect to hydrolyzable substrates and sites of hydrolysis.

Cloning and functional characterization through antisense mapping of a kappa 3-related opioid receptor

We have identified a putative opioid receptor from mouse brain (KOR-3), belonging to the G protein-coupled receptor family, that is distinct from the previously cloned mu, delta, and kappa 1 receptors. Assignment of the clone to the opioid receptor family derives from both structural and functional studies. Its predicted amino acid sequence is highly homologous to that of the other opioid receptors, particularly in many of the transmembrane regions, where long stretches are identical to mu, delta, and kappa 1 receptors. Both cyclazocine and nalorphine inhibit cAMP accumulation in COS-7 cells stably expressing the clone. Northern analysis shows that the mRNA is present in brain but not in a number of other organs. Southern analysis suggests a single gene encoding the receptor. A highly selective monoclonal antibody directed against the native kappa 3 receptor recognizes, in Western analysis, the clone expressed in COS-7 cells. The in vitro translation product is also labeled by the antibody. Additional clones reveal the presence of several introns, including one in the second extracellular loop and another in the first transmembrane region. Antisense studies with an oligodeoxynucleotide directed against a region of the second extracellular loop reveal a selective blockade of kappa 3 analgesia in vivo that is not observed with a mismatch oligodeoxynucleotide based upon the antisense sequence. The mu, delta, and kappa 1 analgesia is unaffected by this antisense treatment. Antisense mapping of the clone downstream from the splice site in the first transmembrane region reveals that six different antisense oligodeoxynucleotides all block kappa 3 analgesia. In contrast, only one of an additional six different antisense oligodeoxynucleotides directed at regions upstream from this splice site is effective. This strong demarcation between the two regions raises the possibility of splice variants of the receptor. An additional clone reveals an insert in the 3' untranslated region. In conclusion, the antibody and antisense studies strongly associate KOR-3 with the kappa 3-opioid receptor, although it is not clear whether it is the kappa 3 receptor itself or a splice variant.

Malignant transformation of angiomyolipoma

Angiomyolipomas are well recognized but uncommon tumors that can involve the kidney. To our knowledge a well documented case of malignant change of angiomyolipoma has never been reported. We report a case of renal angiomyolipoma and leiomyosarcoma with a clearly identified transition of benign to malignant elements seen in the resected tissue.

The effects of ambient temperature on amikacin pharmacokinetics in gopher tortoises

The pharmacokinetics of amikacin were compared in two groups of tortoises, one held at 20 degrees C and the other at 30 degrees C. The mean (+/- SD) residence time for amikacin in the 30 degrees C tortoises was 22.67 +/- 0.50 h; significantly (P less than 0.05) less than those held at 20 degrees C (41.83 +/- 3.23 h). There was no significant difference (P greater than 0.05) in the steady-state volume of distribution (Vd(ss] between the tortoises held at 30 degrees C (0.241 +/- 0.520 l/kg) and those held at 20 degrees C (0.221 +/- 0.019 l/kg). The clearance rate was faster (P less than 0.05) in the warmer tortoises (10.65 +/- 2.42 ml/min/kg at 30 degrees C compared to 5.27 +/- 0.152 ml/min/kg at 20 degrees C). These data indicate that while the volume of distribution was approximately the same, amikacin remained in the colder tortoises longer because of its slower elimination. The oxygen consumption and metabolism were measured and found to be lower in the colder tortoises, almost by the same 2:1 ratio as clearance time (Cl), mean residence time (MRT), and area under the curve (AUC). The data derived from this limited study indicated that an appropriate therapeutic dosage regimen for amikacin in gopher tortoises at 30 degrees C is 5 mg/kg given i.m. every 48 h.

A rapid method for detection of cellular proliferation using carboxyfluorescein. Assay of growth factors (IL-2, IL-1) and growth inhibiting antibodies

The uptake of carboxyfluorescein diacetate (CFDA) into live cells was used as the basis for a simple, rapid and fully automated micromethod for determination of cell growth. The aim of the investigation was to adapt the CFDA method for detection of cell growth factors from cell culture supernatants. Thus, the biological activities of the growth factors IL-2 or IL-1 could be detected and quantitated at the same level of sensitivity as with the conventional [3H]thymidine incorporation. Similarly, the method was well suited to assay inhibition of IL-2-dependent lymphocyte growth by the monoclonal antibody anti-Tac, binding to the human lymphocyte membrane receptor for IL-2. The CFDA method proved to be rapid, reliable and well suited for several applications involving limiting numbers of cells and biological reagents.

Amebiasis in red-footed tortoises

Of 500 red-footed tortoises imported to southern Florida, approximately 200 died during a 2-month period. Clinical signs were nonspecific and included anorexia, listlessness, and watery diarrhea, with lingering death. Necropsy consistently revealed thickened duodenum, with necrotic mucosa and multifocal to diffuse areas of hepatic necrosis. Histologic evaluation of tissues demonstrated numerous amebae in intestinal and hepatic lesions.

Taurine uptake by cultured human lymphoblastoid cells

Cultured human lymphoblastoid cells take up taurine from the medium by two processes: 1) a temperature-dependent, Na+-dependent, saturable "active"-transport system and 2) diffusion. The active transport has properties similar to those reported for taurine transport by other tissues. Apparent Km is about 25 microM and Vmax about 7.2 pmol/min/10(6) cells; saturation occurs at 100 microM taurine. Uptake is competitively inhibited by the beta-amino acids hypotaurine (50% inhibition at 44 microM) and beta-alanine (50% at 152 microM), as measured at 50 microM taurine. Taurocyamine inhibits 50% at 260 microM. Chlorpromazine and imipramine are strong uncompetitive inhibitors, giving 50% inhibition at 26 microM and 115 microM, respectively; at these concentrations cellular viability per se is not affected. Ouabain inhibits 40-50% over a concentration range of 4-500 microM. Diffusion of taurine into the cells is proportional to concentration up to 20 mM. However, at the concentration of taurine in human plasma, 40-100 microM, active transport would provide 90% of the taurine taken up.

Safety and efficacy of intravenous quinidine

The safety and efficacy of intravenous quinidine were evaluated in a patient population with a high prevalence of left ventricular dysfunction and intraventricular conduction delays. Quinidine gluconate (mean dose 9.1 +/- 1.6 mg/kg) was administered during electrophysiologic study to 100 patients with ventricular or supraventricular tachyarrhythmias. Clinical heart failure was present in 68 percent of the patients. Left ventricular end-diastolic pressure, cardiac index, and left ventricular ejection fraction were abnormal in 62, 48, and 70 percent, respectively. Major intraventricular conduction delays (QRS of 120 msec or more) were present in 27 percent, and the H-V interval was prolonged (over 55 msec) in 28 percent. Despite the prevalence of these abnormalities, quinidine was discontinued because of hypotension in only 10 patients. Saline solution was infused to maintain preload in 37 percent, and hypotension responded promptly to saline solution infusion or discontinuation of quinidine infusion in all subjects. Hypotension was not more common in patients with more severe left ventricular dysfunction. QRS duration, H-V interval, QTc, and right ventricular effective refractory period increased significantly (p less than 0.001) after quinidine administration. Heart block or QRS widening of 50 percent or more did not occur. Quinidine prevented arrhythmia induction in 26 percent of patients who received full doses. Ventricular tachycardia cycle length increased in all 41 patients in whom identical forms were induced before and after quinidine (287 +/- 71 msec versus 361 +/- 93 msec, p less than 0.001). Intravenous quinidine may be administered safely to patients with intraventricular conduction delays and moderate heart failure. When antiarrhythmic efficacy is assessed by electrophysiologic study, quinidine compares favorably with other antiarrhythmic agents.