Mutation of the galectin-3 glycan-binding domain (Lgals3-R200S) enhances cortical bone expansion in male mice and trabecular bone mass in female mice

We previously observed that genomic loss of galectin-3 (Gal-3; encoded by Lgals3) in mice has a significant protective effect on age-related bone loss. Gal-3 has both intracellular and extracellular functionality, and we wanted to assess whether the affect we observed in the Lgals3 knockout (KO) mice could be attributed to the ability of Gal-3 to bind glycoproteins. Mutation of a highly conserved arginine to a serine in human Gal-3 (LGALS3-R186S) blocks glycan binding and secretion. We generated mice with the equivalent mutation (Lgals3-R200S) and observed a subsequent reduction in Gal-3 secretion from mouse embryonic fibroblasts and in circulating blood. When examining bone structure in aged mice, we noticed some similarities to the Lgals3-KO mice and some differences. First, we observed greater bone mass in Lgals3-R200S mutant mice, as was previously observed in Lgals3-KO mice. Like Lgals3-KO mice, significantly increased trabecular bone mass was only observed in female Lgals3-R200S mice. These results suggest that the greater bone mass observed is driven by the loss of extracellular Gal-3 functionality. However, the results from our cortical bone expansion data showed a sex-dependent difference, with only male Lgals3-KO mice having an increased response, contrasting with our earlier study. These notable sex differences suggest a potential role for sex hormones, most likely androgen signaling, being involved. In summary, our results suggest that targeting extracellular Gal-3 function may be a suitable treatment for age-related loss of bone mass.

Loss of Lgals3 Protects Against Gonadectomy-Induced Cortical Bone Loss in Mice

Sex hormone deprivation commonly occurs following menopause in women or after androgen-depletion during prostate cancer therapy in men, resulting in rapid bone turnover and loss of bone mass. There is a need to identify novel therapies to improve bone mass in these conditions. Previously, we identified age- and sex-dependent effects on bone mass in mice with deletion of the gene encoding the β-galactoside binding lectin, galectin-3 (Lgals3-KO). Due to the influence of sex on the phenotype, we tested the role of sex hormones, estrogen (β-estradiol; E₂), and androgen (5α-dihydroxytestosterone; DHT) in Lgals3-KO mice. To address this, we subjected male and female wild-type and Lgals3-KO mice to gonadectomy ± E₂ or DHT rescue and compared differential responses in bone mass and bone formation. Following gonadectomy, male and female Lgals3-KO mice had greater cortical bone expansion (increased total area; T.Ar) and reduced loss of bone area (B.Ar). While T.Ar and B.Ar were increased in response to DHT in wild-type mice, DHT did not alter these parameters in Lgals3-KO mice. E₂ rescue more strongly increased B.Ar in Lgals3-KO compared to wild-type female mice due to a failure of E₂ to repress the increase in T.Ar following gonadectomy. Lgals3-KO mice had more osteoblasts relative to bone surface when compared to wild-type animals in sham, gonadectomy, and E₂ rescue groups. DHT suppressed this increase. This study revealed a mechanism for the sex-dependency of the Lgals3-KO aging bone phenotype and supports targeting galectin-3 to protect against bone loss associated with decreased sex hormone production.

Regulation of cytoskeleton and adhesion signaling in osteoclasts by tetraspanin CD82

We used a myeloid-specific Cre to conditionally delete CD82 in mouse osteoclasts and their precursors. In contrast to global loss of CD82 (gKO), conditional loss of CD82 (cKO) in osteoclasts does not affect cortical bone, osteoblasts, or adipocytes. CD82 loss results in greater trabecular volume and trabecular number but reduced trabecular space in 6-month old male mice. Though this trend is present in females it did not reach significance; whereas there was an increase in osteoclast numbers and eroded surface area only in female cKO mice. In vitro, there is an increase in osteoclast fusion and defects in actin assembly in both gKO and cKO mice, irrespective of sex. This is accompanied by altered osteoclast morphology and decreased release of CTX in vitro. Integrin αvβ3 expression is reduced, while integrin β1 is increased. Signaling to Src, Syk, and Vav are also compromised. We further discovered that expression of Clec2 and its ligand, Podoplanin, molecules that also signal to Syk and Vav, are increased in differentiated osteoclasts. Loss of CD82 reduces their expression. Thus, CD82 is required for correct assembly of the cytoskeleton and to limit osteoclast fusion, both needed for normal osteoclast function.

Global deletion of tetraspanin CD82 attenuates bone growth and enhances bone marrow adipogenesis

CD82 is a widely expressed member of the tetraspanin family of transmembrane proteins known to control cell signaling, adhesion, and migration. Tetraspanin CD82 is induced over 9-fold during osteoclast differentiation in vitro; however, its role in bone homeostasis is unknown. A globally deleted CD82 mouse model was used to assess the bone phenotype. Based on microCT and 4-point bending tests, CD82-deficient bones are smaller in diameter and weaker, but display no changes in bone density. Histomorphometry shows a decrease in size, erosion perimeter, and number of osteoclasts in situ, with a corresponding increase in trabecular surface area, specifically in male mice. Male-specific alterations are observed in trabecular structure by microCT and in vitro differentiated osteoclasts are morphologically abnormal. Histomorphometry did not reveal a significant reduction in osteoblast number; however, dynamic labeling reveals a significant decrease in bone growth. Consistent with defects in OB function, OB differentiation and mineralization are defective in vitro, whereas adipogenesis is enhanced. There is a corresponding increase in bone marrow adipocytes in situ. Thus, combined defects in both osteoclasts and osteoblasts can account for the observed bone phenotypes, and suggests a role for CD82 in both bone mesenchyme and myeloid cells.

Adherence to and effects on physical function parameters of a community-based standardised exercise programme for overweight or obese patients carried out by local sports clubs

OBJECTIVES

To evaluate the adherence to a sports-club-based standardised real-life exercise programme for overweight or obese patients. The effects on physical function parameters, anthropometry and quality of life were also assessed.

STUDY DESIGN

Within this prospective cohort study data from patients in Austrian sports-club-based programmes were analysed.

METHODS

Sports-club-based programmes were held twice a week and carried out by local trainers. The target group was overweight or obese patients. Adherence was determined after 2 and 6 months, and physical function parameters were evaluated at baseline and after 2 months.

RESULTS

A total of 71 patients (age: 52.0; standard deviation [SD: 12.1] years; body mass index [BMI]: 37.3 [SD: 8.2] kg/m²) took part in the study. Within the first 2 months the adherence rate was 62%, while 20% (14/71) participated in ≥75% of all offered sessions. After 6 months, 49% (17/35) of the retained sample still participated regularly in an exercise class. At baseline, muscle strength represented only 70% of the age- and sex-specific reference values and could be increased in a range from +4.0% (1.3 [SD: 3.0] kg; muscular endurance for the pectoral muscles) to +22.5% (16.1 [SD: 17.5] kg) (muscular endurance for the lower limb muscles). Concerning endurance capacity, the heart rate for a constant submaximal workload decreased from 126.4 (SD: 21.7) beats per minute at baseline to 120.9 (SD: 21.1) after 2 months (P < 0.001).

CONCLUSIONS

Sports clubs, as a non-clinical setting, can offer attractive standardised exercise programmes for a minority of overweight or obese patients. Long term changes in life-style, that result in sufficient levels of health enhancing physical activity still remain a huge public health challenge.

[Baseline- and health enhancing physical activity in adults with obesity]

Physical inactivity is one of the major risk factors for people to become overweight or obese. To achieve a substantial health benefit, adults should do at least 150 min of moderate or 75 min of high intensity aerobic activity per week and additionally they should do muscle strengthening exercises. This recommendation represents the lower limit and not the optimum. To loose body weight a significantly higher level of physical activity is required. Exercise programs can play an important part to reach the required level of health-enhancing physical activity. The Austrian pilot projects "Aktiv Bewegt" and "GEHE-Adipositas" showed that obese adults were interested in structured exercise programs and that they were also willing to use them. Clear defined quality criteria, the differentiation from conventional programs for already active and fit people and a recommendation from a doctor or other health professionals were important motivation reasons.

Is the umbo matrix of bivalve shells (Laternula elliptica) a climate archive?

Heavy metal accumulation into bivalve soft tissues has received increasing interest in recent years with respect to biomonitoring of environmental change including pollution. To a lesser extent, accretion of elements from the environment into bivalve hard structures (shells) has been investigated, although the importance of the shells as environmental archives has been acknowledged. Here we report element distribution within consecutive growth bands in the shells of the Antarctic soft shell clam Laternula elliptica, which is currently exposed to vast environmental change in Antarctic Peninsula coastal environments that undergo rapid climate warming. We performed a high spatial resolution analysis for Al, Fe, Mn, Cu, Pb and U in the shell umbo, by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Element ratios within the umbo did not resemble either the ratios in the surrounding seawater, the sedimenting material in Potter Cove, or even the Earth's crust basal composition. Mn and Cu were preferentially incorporated into the umbo. A strong decrease of element accretion with time could be related to lifetime respiration mass (R) of the animals. This indicates element accretion into the umbo and shell matrix to be largely a function of animal ecophysiology and life history, and these effects need to be considered in the context of potential usefulness of L. elliptica shells as environmental archives.

Association of the kappa-opioid system with alcohol dependence

Opioid receptors and their endogenous peptide ligands play important roles in the reward and reinforcement of drugs such as heroin, cocaine, and alcohol. The binding of dynorphins to the kappa-opioid receptor has been shown to produce aversive states, which may prevent the development of reinforcement. We genotyped SNPs throughout OPRK1, encoding the kappa-opioid receptor, and PDYN, which encodes its ligand prodynorphin, in a group of 1860 European American individuals from 219 multiplex alcohol dependent families. Family-based analyses demonstrated associations between alcohol dependence and multiple SNPs in the promoter and 3' end of PDYN, and in intron 2 of OPRK1. Haplotype analyses further supported the association of PDYN. Thus, variations in the genes encoding both the kappa-opioid receptor and its ligand, OPRK1 and PDYN, are associated with the risk for alcohol dependence; this makes biological sense as variations in either should affect signaling through the kappa-opioid system.

Ghrelin is not suppressed in hyperglycemic clamps by gastric inhibitory polypeptide and arginine

Systemic ghrelin concentration falls rapidly after nutrient ingestion in vivo. The effect incretins on ghrelin secretion in humans remains unclear. We quantified circulating ghrelin concentrations under hyperglycemic conditions combined with infusion of gastric inhibitory polypeptide (GIP) and arginine.

METHODS

Eight healthy volunteers were studied with a hyperglycemic clamp followed by addition of GIP (2 pmol.kg(-1).min(-1), 60-115 min) and an arginine-bolus and -infusion (10 mg.kg(-1).min(-1), 90-115 min).

RESULTS

Hyperglycemia alone increased circulating insulin concentrations (p<0.01), and decreased ghrelin concentrations to 89.8% of basal (p=0.208). GIP-infusion resulted in circulating insulin concentration of 1109+/-942 pmol/l (p<0.02) and no further decrease of ghrelin (86.2% of baseline, p=0.050). Under arginine- and GIP-infusion together, insulin concentrations increased progressively to 3005+/-1604 pmol/l (p<0.01) without further decreasing in ghrelin concentrations (98.9% of baseline, p=0.575).

CONCLUSIONS

Hyperglycemic hyperinsulinemia and further increases of hyperinsulinemia to supraphysiological and high supraphysiological concentrations under GIP- and arginine-infusion do not significantly decrease ghrelin concentrations in healthy subjects. Moreover, there is no dose-dependent suppression of ghrelin by insulin in the hyperglycemic condition. Neither GIP nor arginine affected ghrelin release.

Laboratory diagnosis of Ebola and Marburg hemorrhagic fever

The control of Filovirus outbreaks can be greatly enhanced by timely laboratory confirmation of infection or the identification of alternative disease processes. The status of current laboratory diagnostics for Ebola and Marburg virus infections is discussed in terms of the assays available and their interpretation. In addition, the role of field-based laboratory support and its limitations and capabilities in an outbreak response setting, especially in regards to real-time PCR and immunofiltration assays, is presented.

Transplantation of livers from hbc Ab positive donors into HBc Ab negative recipients: a strategy and preliminary results

Here we describe a strategy for using livers from hepatitis B core antibody (anti-HBc) positive donors in anti-HBc negative recipients and report our preliminary results. Adult anti-HBc negative recipients were immunized against hepatitis B virus (HBV) prior to transplantation. Liver biopsies from anti-HBc positive, HBs Ag negative donors were performed at the time of procurement to rule out acute hepatitis or chronic liver disease. Donor serum and liver samples were collected for HBV DNA analysis by PCR. Recipients were given HBIG (10000 units, i.v.) during the anhepatic phase of transplantation. Patients were treated with lamivudine (150 mg) beginning on postoperative day (POD) 1. If HBV DNA was not detected in either donor liver or serum by PCR, recipient antiviral therapy was stopped. If donor liver and serum were positive for HBV DNA by PCR, the recipient was maintained on combination lamivudine and HBIG therapy. If HBV DNA was detected in donor liver but not in donor serum, the patient was managed on lamivudine therapy alone. Between February 1999 and June 2000, six anti-HBc negative recipients received liver transplants from anti-HBc positive donors. PCR analysis of serum from the six donors was negative for HBV DNA in each, while donor liver PCR analysis was positive in five of six for HBV DNA. Accordingly, all patients were given HBIG in the anhepatic phase of transplantation and five of six were maintained on daily lamivudine therapy. Follow-up periods have ranged from 2 to 18 months. There has been no emergence of de novo hepatitis B. Serial serum HBs Ag and HBV DNA assays have all proven negative. Moreover, while on lamivudine therapy, 2 patients now have undetectable HBV DNA in hepatic allograft biopsies by PCR analysis. Our strategy for using livers from anti-HBc donors has yielded promising initial results. De novo hepatitis B has not occurred and our data suggest residual hepatitis B virus may be eradicated in recipients maintained on lamivudine therapy.

Alpha-1 antitrypsin deficiency and splenic artery aneurysm rupture: an association?

OBJECTIVE

Theoretically, patients with alpha 1-antitrypsin deficiency may be vulnerable to the development of splenic artery aneurysms. alpha-1 antitrypsin deficiency can induce cirrhosis with portal hypertension, and resulting protease-antiprotease imbalances may exaggerate arterial wall weakness due to proteolysis of arterial structural proteins. A splenic artery aneurysm rupture 7 days after liver transplantation provoked a reassessment of the incidence of this phenomenon in a liver transplant population.

METHODS

Case records from three institutions and the results of a survey sent to 126 liver transplantation programs in the United Network for Organ Sharing database were reviewed. The incidence of splenic artery aneurysm rupture in the peritransplantation period, etiology of liver disease associated with this phenomenon, and recommendations regarding management of splenic artery aneurysms was assessed.

RESULTS

Twenty-one cases of splenic artery aneurysm rupture were identified. alpha-1 antitrypsin deficiency was the most common cause of cirrhosis in the majority of identified patients who presented with splenic artery aneurysm rupture, which was associated with a mortality rate of 57%. Respondents to the survey indicated that a preoperative evaluation was warranted if a splenic artery aneurysm was suspected; however, no consensus regarding management exists.

CONCLUSIONS

The presence and risk of rupture of splenic artery aneurysms may be greater in patients with alpha-1 antitrypsin deficiency. If identified before rupture, an aggressive approach to diagnosing and treating these aneurysms should be initiated. At present, no consensus exists regarding the management of splenic artery aneurysms.

Liver transplantation: perspectives after 250 liver transplants at the Ochsner Clinic

At the Ochsner Clinic we recently performed our 250th liver transplant. Reaching this milestone has led us to reflect back on the history of liver transplant, both at our own institution and nationally, noting the many achievements and improvements in liver transplantation during the relatively brief history of this therapeutic modality. Furthermore, there are a number of issues both medical and political which will likely be affecting how liver transplantation is performed in the future.

Liver transplantation for hepatocellular carcinoma: one center's experience, 1987-1994

A retrospective review was done to evaluate the detection of hepatocellular carcinoma preoperatively, using ultrasonography and alpha-fetoprotein in patients awaiting orthotopic liver transplantation. Sixteen of the 187 patients who underwent 209 orthotopic liver transplantations at the Ochsner Transplant Center from 1987 to 1994 were diagnosed with hepatocellular carcinoma, 3 preoperatively and 11 at the time of pathological inspection of the liver explant. Two developed metastatic hepatocellular carcinoma while awaiting orthotopic liver transplantation. Ultrasonography detected abnormalities in the region where hepatoma was identified in 5 of 11 (45%) patients with incidental hepatocellular carcinoma, in all 3 with overt hepatocellular carcinoma, and in neither of the 2 who developed metastatic hepatocellular carcinoma while awaiting orthotopic liver transplantation. Hepatocellular carcinoma was present in 5 of 23 (22%) patients with an alpha-fetoprotein greater than 20 ng/mL and in 3 of 10 (30%) with an alpha-fetoprotein greater than 50 ng/mL.

Mitochondrial abnormalities in oculopharyngeal muscular dystrophy

This report describes a 56-yr-old man with a dominantly inherited disorder affecting four generations and characterized by bilateral ptosis and dysphagia. Muscle biopsy showed only minor light microscopic abnormalities but electron microscopy revealed fibres containing paracrystalline mitochondrial inclusions. Southern analysis of mitochondrial DNA obtained from muscle did not reveal mitochondrial gene deletions. An extensive search eventually identified the characteristic intranuclear filaments of oculopharyngeal muscular dystrophy (OPMD). Abnormal mitochondria are non-specific epiphenomena in OPMD but a potential source of confusion with a late-onset mitochondrial cytopathy. This case further emphasizes the necessity for a diligent search for the diagnostic intranuclear filaments when oculopharyngeal muscular dystrophy is suspected clinically.

Skin reservoir formation and bioavailability of dermally administered chemicals in hairless guinea pigs

There is concern as to whether dermally applied chemicals that remain in the skin after exposure are bioavailable and should be included as part of the systemic dose; this study was conducted to investigate the temporal relationship between the skin depot and absorbed dose. Single doses of 14C-labelled phenanthrene, benzo[a]pyrene or di(2-ethylhexyl) phthalate were administered dermally to groups of four female, Hartley hairless guinea pigs which were housed individually in metabolism cages to collect urine and faeces for radioassay. The animals were sacrificed at 6 hr, 24 hr, 48 hr, 7 days or 14 days after dosing to harvest skin specimens for the determination of radioactivity by autoradiographic and liquid scintillation methods, and to determine the dose that remained in the body. It was found that for all three compounds the amount of chemical left in the skin decreased over time while the cumulative percent dose excreted in urine and faeces increased. The autoradiographic results were consistent with those obtained from the liquid scintillation method showing a gradual decrease in radioactivity grain accumulation over the time periods for the three compounds, with the highest grain density observed around hair follicles of the skin. The results of this study indicate that the chemicals left in the skin after surface washing eventually enter the systemic circulation and should be considered as part of the total dose absorbed, and that the hair follicle may play an important role in percutaneous penetration.

In vitro and in vivo percutaneous absorption of 14C-chloroform in humans

Chloroform has been found in potable water and there is concern that significant dermal absorption may arise from daily bathing and other activities. The present study examines percutaneous absorption of 14C-chloroform in vivo using human volunteers and in vitro using fresh, excised human skin in a flow-through diffusion cell system. Fifty microlitre doses of either 1000 micrograms ml-1 chloroform in distilled water, (16.1 micrograms cm-2) or 5000 micrograms ml-1 of chloroform in ethanol, (80.6 micrograms cm-1) were applied to the forearm of volunteers with exhaled air and urine being collected for analysis. Single doses of either 0.4 microgram ml-1 chloroform in distilled water (low dose, 0.62 microgram cm-2, 1.0 ml dosed) or 900 micrograms ml-1 chloroform in distilled water (high dose, 70.3 micrograms cm-2, 50 microliters dosed) were applied to discs of the excised abdominal skin placed in flow-through diffusion cells and perfused with Hepes buffered Hank's balanced salt solution, with a wash at 4 h. In vivo absorption was 7.8 +/- 1.4% (water as vehicle) and 1.6 +/- 0.3% (ethanol as vehicle). Of the dose absorbed in vivo, more than 95% was excreted via the lungs (over 88% of which was CO2), and the maximum pulmonary excretion occurred between 15 min and 2 h after dosing. The percentage of dose absorbed in vitro (skin+perfusate) was 5.6 +/- 2.7% (low dose) and 7.1 +/- 1.4% (high dose). The above data demonstrate that a significant amount of the dissolved chloroform penetrates through the human skin, and that a higher percentage of the applied dose was absorbed using water as vehicle.(ABSTRACT TRUNCATED AT 250 WORDS)

Serological studies on the infection of dogs in Ontario with Borrelia burgdorferi, the etiological agent of Lyme disease

A serological study was undertaken to determine whether dogs in Ontario are being exposed to Borrelia burgdorferi, the etiological agent of Lyme disease. This study consisted of a survey of randomly selected dogs and testing of diagnostic submissions from candidate Lyme disease cases. The survey of 1,095 dogs, bled between January 1988 and August 1989, revealed a total of 65 (5.9%) enzyme-linked immunosorbent assay (ELISA) reactors, of which 22 had immuno-fluorescent antibody assay (IFA) titers >/=1:32. All but one of the IFA-positive and 10 of the ELISA-positive, IFA-negative sera were further tested by western blot. Eight western blot positive and three equivocal reactors were obtained. Three of the eight confirmed reactors had visited areas known to be endemic for Lyme disease, leaving five reactors that might have been infected in previously undocumented areas for B. burgdorferi activity in Ontario. Diagnostic submissions of sera from 223 dogs were received between August 1987 and February 1992. Test results revealed 21 (9.4%) IFA reactors, of which only six had significant titers (>/=1:256) and were reactive by an immunodot Borrelia test. All six dogs had travelled to known Lyme endemic areas. Based on results obtained from this study, it seems likely that the agent of Lyme disease is not widespread in Ontario.

Cervical spondylotic myelopathy with occult foramen magnum meningioma--a case for MRI?

A fatal case of occult foramen magnum meningioma is described which presented with features of cervical myelopathy confirmed by cervical myelogram. Surgical decompression led to initial improvement followed by progressive deterioration and death. Postmortem examination revealed a 4 cm diameter foramen magnum meningioma. The dangers of using only standard radiographic investigations of the cervical cord are discussed.

Computerized patient anesthesia records: less time and better quality than manually produced anesthesia records

STUDY OBJECTIVE

To compare manual and computerized anesthesia information management systems (AIMS's) with respect to time demands on the anesthetist and record quality.

DESIGN

Videotaped clinical anesthesia cases were independently reviewed along with the records produced.

SETTING

Private practice anesthesia at a 150-bed community hospital.

PATIENTS

Ten consecutive ASA physical status I patients having video arthroscopy of the knee by the same surgeon and having general anesthesia.

INTERVENTIONS

One anesthetist recorded six cases: three with the computer and three manually. Two more anesthetists each recorded two cases: one with the computer and one manually.

MEASUREMENTS AND MAIN RESULTS

The proportion of the anesthetist's time spent on the documentation for the computer records was significantly less than that spent on manual records (14.9% vs. 36.6%; p < 0.001). Nevertheless, significantly more vital sign data points were recorded on the computer than on the manual records (245.2 vs. 45.0 vital sign points per case; p < 0.001), as well as significantly more notes and drug information (61.0 vs. 40.0 notes per case; p < 0.02). The computer record was always legible, but this was not the case with the manual records. There was no significant difference in the number of artifacts detected on the records.

CONCLUSION

The concern that the introduction of computerized AIMS's may complicate the anesthesia working environment by requiring more time than manual AIMS's and thus detracting from direct patient care is not supported by this study. In fact, this computer approach not only required less time but also produced a more complete and higher-quality record than did the manual AIMS.

Ulceration in necrobiosis lipoidica--a case report and study

A case of aggressive ulceration of necrobiosis lipoidica was successfully treated with oral prednisolone. A retrospective study of 23 cases of necrobiosis lipoidica revealed a 13% incidence of ulceration. The pathogenesis, clinical features and treatment of ulceration in necrobiosis lipoidica are discussed.

Effect of cocaine, lidocaine kindling and carbamazepine on batrachotoxin-induced phosphoinositide hydrolysis in rat brain slices

Repeated administration of a subconvulsant dose of a local anesthetic will eventually induce seizures, a phenomenon similar to electrical kindling. We have investigated the effect of repeated lidocaine and cocaine administration on the phosphoinositide (PI) hydrolysis induced by batrachotoxin (BTX), a specific Na channel activator. Rats were injected with cocaine or saline daily for 6 days and PI hydrolysis was assayed in sliced frontal cortex. Cocaine treatment had no effect on BTX-induced PI hydrolysis while in vitro cocaine blocked the BTX effect. In a second experiment, rats received daily injections of lidocaine or saline. After a rat developed at least two seizures, it was sacrificed together with a rat receiving lidocaine injections which had never seized and a rat receiving saline injections. Basal, BTX and ibotenic acid (IBO; a glutamate receptor agonist)-stimulated PI hydrolysis did not differ among the three groups in slices of either hippocampus (HC) or piriform cortex (PC) though IBO-stimulated PI hydrolysis was much greater in the HC than in the PC. Neither in vitro nor in vivo carbamazepine altered the effect of cocaine on BTX-induced PI hydrolysis. These results demonstrate that local anesthetic kindling does not alter PI hydrolysis coupled to Na channel or IBO activation.

NMR spectral analysis of cytotoxic ether lipids

Several cytotoxic ether lipid analogs of platelet activating factor exhibit a wide range of interesting pharmacological properties. Furthermore, at least two members of this family of lipids have progressed to phase I clinical trials as potential cancer chemotherapeutic agents. In spite of the promise that these compounds hold as anticancer drugs, they remain poorly characterized. We report herein the first complete 1H NMR analysis of several palmityl-based ether lipids. In addition, we report the 13C NMR spectral assignments for these lipids, which are based, in part, on both the presence and magnitude of 31P-13C and 14N-13C coupling constants.

M modes in a diode side-pumped Nd:glass slab laser

We have operated a pulsed Nd:glass slab laser in a hemiconfocal cavity with beam stops to produce a multibounce beam in the shape of the letter M. This configuration permits the extraction of diffraction-limited beams from a large volume of the slab. The output of the slab was in four beams, and the optical slope efficiency was 14%.

Blue parametric generation from temperature-tuned LiB(3)O(5)

We have demonstrated optical parametric generation from 470 to 487 mn with LiB(3)O(5), using a 355-nm pump in a noncritical phase-matched orientation by temperature tuning. A Conversion efficiency of 9% at 480 nm was achieved at room temperature.

Getting into the act: a Canadian nurse's experience

The Canada Health Act became law in April 1984 after years of debate and negotiations. The Canadian Nurse's Association (CNA) with a membership of 169,000 took a leading role in the lobby to influence that act, the guiding legislation for Canada's national health insurance system. The CNA lobbied for changes in the Canada Health Act that implied fundamental reforms in the health care delivery system. This paper will chronicle the political activity of CNA and its twelve member associations as they sought to influence the design of the new legislation.