A comparison of the abuse liability and dependence potential of nicotine patch, gum, spray and inhaler

RATIONALE

Nicotine replacement therapy (NRT) in varying forms is becoming widely used. Clinicians, therapists and regulatory authorities are interested in the abuse liability and dependence potential of the different forms.

OBJECTIVES

To compare the abuse liability and dependence potential of nicotine gum, transdermal patch, spray and inhaler.

METHODS

504 male and female smokers seeking help with stopping smoking were randomly allocated to the four products. Measures were taken at the designated quit date, then 1 week, 4 weeks, 12 weeks and 15 weeks later. Smokers were advised to use the product for up to 12 weeks. Those still using the product at the 12-week visit were advised to cease use by week 14. Measures included: pleasantness and satisfaction ratings at weeks 1 and 4 (used as a marker of abuse liability); ratings of feeling dependent on NRT at weeks 1, 4, 12 and 15 (used as a marker of subjective dependence); mood and physical symptoms ratings at weeks 12 and 15 (the change being used to assess physical dependence on NRT), continued usage of NRT at week 15 (used as an marker of behavioural dependence).

RESULTS

Average ratings of pleasantness were low. The nicotine patch was rated as less unpleasant to use than all other products. There were no significant differences between the products in terms of satisfaction or subjective dependence except at week 15 when no patch users rated themselves as dependent. Continued use of NRT at week 15 was related to rate of delivery of nicotine from the products - 2% for patch, 7% for gum and inhaler, 10% for spray (P<0.05 for linear association). Among those

Proteomics of the chloroplast: systematic identification and targeting analysis of lumenal and peripheral thylakoid proteins

The soluble and peripheral proteins in the thylakoids of pea were systematically analyzed by using two-dimensional electrophoresis, mass spectrometry, and N-terminal Edman sequencing, followed by database searching. After correcting to eliminate possible isoforms and post-translational modifications, we estimated that there are at least 200 to 230 different lumenal and peripheral proteins. Sixty-one proteins were identified; for 33 of these proteins, a clear function or functional domain could be identified, whereas for 10 proteins, no function could be assigned. For 18 proteins, no expressed sequence tag or full-length gene could be identified in the databases, despite experimental determination of a significant amount of amino acid sequence. Nine previously unidentified proteins with lumenal transit peptides are presented along with their full-length genes; seven of these proteins possess the twin arginine motif that is characteristic for substrates of the TAT pathway. Logoplots were used to provide a detailed analysis of the lumenal targeting signals, and all nuclear-encoded proteins identified on the two-dimensional gels were used to test predictions for chloroplast localization and transit peptides made by the software programs ChloroP, PSORT, and SignalP. A combination of these three programs was found to provide a useful tool for evaluating chloroplast localization and transit peptides and also could reveal possible alternative processing sites and dual targeting. The potential of proteomics for plant biology and homology-based searching with mass spectrometry data is discussed.

Renal effects of amino acid infusion in cardiac surgery

OBJECTIVE

To evaluate effects of amino acids on renal function and oxygen consumption and the role of individual amino acids on renal blood flow (RBF) changes.

DESIGN

Prospective, randomized, controlled study.

SETTING

Operating room in cardiothoracic surgery department, university hospital.

PARTICIPANTS

Twenty-two male patients submitted to elective first-time coronary artery bypass surgery.

INTERVENTIONS

A catheter was placed in the left renal vein for thermodilution RBF measurements and blood sampling. In 11 patients, a balanced mixed amino acid infusion was infused (200 mL/hr) for 30 minutes immediately after the operation.

MEASUREMENTS AND MAIN RESULTS

RBF and glomerular filtration rate increased during amino acid infusion compared with the control group. Renal oxygen consumption increased in the amino acid group and correlated with the increase in RBF (r = 0.70, p<0.001). Amino acid infusion induced two- to fourfold increases in plasma concentrations of individual amino acid concentrations and promoted renal extraction of aspartate, glutamate, glycine, and histidine. No correlation was observed between arterial concentration or uptake of individual amino acids and RBF.

CONCLUSIONS

The increase in RBF from a mixed amino acid infusion was associated with increased glomerular filtration rate and renal consumption of oxygen. Changes in RBF of a mixed amino acid infusion could not be linked to plasma level or renal uptake of any individual amino acids.

Pain and health related quality of life after heart, kidney, and liver transplantation

No study has focused particularly on the sensory and affective experience of bodily pain among transplanted patients. The aim of this study was to explore pain and other factors that influence health related quality of life (HRQOL) in heart, kidney, and liver transplant recipients during the first 2 yr after transplantation, and to define similarities and/or differences in the three groups. A total of 76 patients, 18-60 yr old, undergoing heart, kidney, or liver transplantation between 1995 and 1997 with a follow-up of 6-24 months were included. HRQOL and pain were investigated by using the Short-Form-36 items (SF-36), the Hospital Anxiety and Depression Scale (HAD), and the Pain-O-Meter (POM). Overall, the patients show satisfactory HRQOL. There were no differences in experienced HRQOL 6 24 months after transplantation between kidney, liver, and heart transplant recipients except in the area of Role-Physical (RP). Fifty-three percent of all patients reported bodily pain. The most common locations were the hands, feet, and back, and sensory experiences were burning, stabbing, or dull pain. There was a correlation between number of rejections and total score for POM-VAS (p < 0.05) (rho = 0.47). There was also a correlation between the number of rejection episodes and the total pain intensity score for POM-WDS (p < 0.05) (rho = 0.48). Patients with pain scored higher in the area of depression (p < 0.05). Bodily pain is an important problem after organ transplantation, affecting daily living even in patients with good allograft function and it limits physical function. vitality, and general health.

Randomized comparative trial of nicotine polacrilex, a transdermal patch, nasal spray, and an inhaler

BACKGROUND

There are several nicotine replacement products on the market, and physicians are likely to be asked with increasing frequency about which of these products their patients should use.

OBJECTIVE

To provide a basis for rational advice by comparing nicotine polacrilex (gum), a transdermal patch, nasal spray, and an inhaler.

DESIGN

Randomized trial with assessments at the quit date and 1, 4, and 12 weeks later.

SETTING

Hospital smokers' clinic.

PATIENTS

Male and female community volunteers (N = 504) smoking 10 or more cigarettes per day and seeking help to stop smoking.

INTERVENTIONS

Patients were given brief advice, and purchased their nicotine replacement treatment at approximately half the regular retail price.

MAIN OUTCOME MEASURES

Nicotine replacement treatment use, ratings of withdrawal symptoms, ratings of product characteristics and helpfulness, and biochemically validated continuous lapse-free abstinence.

RESULTS

The products did not differ in their effects on withdrawal discomfort, urges to smoke, or rates of abstinence. The continuous validated 12-week abstinence rates were 20%, 21%, 24%, and 24% in the gum, patch, spray, and inhaler groups, respectively. Compliance with recommended nicotine replacement treatment use was high for the patch, low for gum, and very low for the spray and the inhaler. The spray was underused because of adverse effects more often than the other products. In the subjects using the spray, the level of use among abstainers at week 1 predicted outcome at week 12. The inhaler was rated as more embarrassing to use than the other products, but provided at least as much nicotine as the gum.

CONCLUSION

When asked about nicotine replacement treatment products available, physicians should note that, despite low compliance with the recommended dose of the spray and inhaler and differences in product ratings, overall, there are no notable differences between the products in their effects on withdrawal discomfort, perceived helpfulness, or general efficacy.

The effects of fluoxetine combined with nicotine inhalers in smoking cessation--a randomized trial

AIMS

Nicotine replacement therapy (NRT) is an established aid in stopping smoking, while the role of antidepressants remains uncertain. Antidepressants added to NRT might improve abstinence rates. Our aim was to determine the efficacy of nicotine inhaler and fluoxetine vs. nicotine inhaler and placebo in attempts to quit smoking.

DESIGN

A randomized, double-blind, placebo-controlled trial.

SETTING

A smoker's cessation clinic.

PARTICIPANTS

One hundred volunteers smoking 10 cigarettes/day or more.

INTERVENTIONS

Subjects were instructed to start taking a daily dose of 10 mg of fluoxetine or placebo 16 days before stopping smoking, then 20 mg 10 days before quitting, continuing for up to at least 3 months. Subjects were instructed to use 6-12 units per day of nicotine inhalers after stopping smoking for up to 6 months.

MEASUREMENTS

Continuous abstinence rates recorded at various time points up to 12 months from the quit date.

FINDINGS

The sustained abstinence rate for the inhaler-fluoxetine group was 54%, 40%, 29% and 21% after 1.5, 3, 6 and 12 months, respectively, compared to 48%, 40%, 32% and 23% for the inhaler-placebo group. The differences were not significant at any time point. Abstinence up to 3 months was more likely in older smokers, those with a lower Beck Depression Inventory Score (BDI), lower Fagerström Test of Nicotine Dependence (FTND) score and no history of alcoholism. Fluoxetine appeared to increase abstinence rates among high BDI smokers compared to high BDI smokers assigned placebo. Serum levels of nicotine during treatment in the inhaler-fluoxetine group were lower than in the inhaler-placebo group so that fluoxetine may have reduced inhaler use through a common site of action.

CONCLUSIONS

We found no evidence that fluoxetine treatment when used as an adjunct to NRT in unselected smokers is effective, but there may be an advantage to using it in depressed smokers.

The use of continuous positive airway pressure by face mask and thoracic epidural analgesia after lung transplantation. Gothenburg Lung Transplant Group

OBJECTIVE

To evaluate the clinical use of continuous positive airway pressure (CPAP) and thoracic epidural analgesia (TEA) after lung transplantation (LTx).

DESIGN

Retrospective case series.

SETTING

Cardiothoracic intensive care unit (ICU) at a university hospital.

PARTICIPANTS

All heart-lung, bilateral, and single-lung transplant recipients between 1990 and 1996 at this institution (n = 102).

INTERVENTIONS

Postoperative pain was controlled by a thoracic epidural infusion of bupivacaine, 1 mg/mL, and sufentanil, 1 microg/mL. After extubation, CPAP, 5 to 10 cm H2O by face mask, was used to prevent reperfusion edema.

MEASUREMENTS AND MAIN RESULTS

In 99 patients, the length of ventilation (LOV) was a median of 4.3 hours (range, 1.0 to 312.0 hours). The median LOV was 8.0 hours (range, 1.5 to 41.0 hours) in the heart-lung recipients, 4.5 hours (range, 2.0 to 47.0 hours) in the bilateral-lung recipients, and 3.5 hours (range, 1.0 to 312.0 hours) in the single-lung recipients. Three transplant recipients, all with primary pulmonary hypertension, were prematurely extubated and reintubated because of pulmonary edema. Twelve hours after extubation, the median oxygenation index (PaO2/F(I)O2, PaO2 in kilopascal units) was greater than 35. The median ICU length of stay for all transplant recipients was 4 days (range, 2 to 270 days).

CONCLUSION

The postoperative use of CPAP and TEA is associated with early and safe tracheal extubation after LTx and may shorten ICU stay.

A proteome analysis of livers from obese (ob/ob) mice treated with the peroxisome proliferator WY14,643

The PPAR (peroxisome proliferator activated receptor) transcription factors are ligand-activated receptors which regulate genes involved in lipid metabolism and homeostasis. PPARalpha is preferentially expressed in the liver and PPARgamma preferentially in adipose tissue. Activation of PPARalpha leads to peroxisome proliferation in rodents and increased beta-oxidation of fatty acids. PPARgamma-activation leads to adipocyte differentiation and improved insulin signaling of mature adipocytes. Both of these PPAR receptors are potential targets for treatment of dyslipidemia in man. Studies by others using a proteomics approach have characterized the effects of PPARalpha agonists in livers from lean healthy mice. However, we wanted to map the effects of a therapeutic dose of a PPARalpha agonist in a disease model of insulin resistance and diabetes, the obese diabetic ob/ob mouse, by proteomics. Therefore, ob/ob mice, which have highly elevated levels of plasma triglycerides, glucose and insulin, were treated for one week with WY14,643 (180 micromol/kg/day), a well-characterized selective PPARalpha agonist. Plasma triglycerides, glucose and insulin levels were determined and we found significant therapeutic effects on triglycerides and glucose levels. The liver protein compositions were investigated by high-resolution two-dimensional gel electrophoresis which showed that WY14,643 produced up-regulation of at least 16 spots. These were identified by mass spectrometry and 14 spots were found to be components of the peroxisomal fatty acid metabolism. Thus, WY14,643 at a therapeutic dose, caused induction of peroxisomal fatty acid beta-oxidation in obese diabetic mice.

The long-term effect of nicotine on the oral mucosa

AIMS

Although nicotine replacement therapy (NRT) has been used to aid smoking cessation for the last 20 years, little information exists on the effect of nicotine products on the oral mucosa, particularly with regard to the direct effect at the site of application. This study aimed to assess the oral safety of a new sublingual tablet containing 2 mg nicotine with regard to lesions at the site of application.

DESIGN

Prospective follow-up to 12 months of smokers using the 2-mg sublingual tablet over a period of 3-6 months.

SETTING

A smoking cessation programme.

PARTICIPANTS

Thirty smokers.

MEASUREMENTS

Oral mucosa was inspected and photographed at each visit. At 6 months, subjects were asked for consent to take a biopsy from the site of application.

FINDINGS

Spontaneous smoking cessation outcome at 12 months was 27% allowing for lapses. At baseline 21 mucosal lesions were diagnosed in 15 subjects. After 6 months eight lesions were observed in six subjects. The predominant diagnosis at all visits was melanin pigmentation. Eight subjects had lesions in the floor of the mouth during the 6-month medication period, all of which appeared in the first 1-6 weeks of treatment. By the 6-month visit all such lesions had resolved. The local symptoms were all mild and tolerable.

CONCLUSION

The sublingual tablet appears to be a safe form of administration of nicotine with mild and transient effects on the floor of the mouth.

[Antibiotic resistance of Helicobacter pylori in Malmö. Therapeutic success in spite of antibiotic resistance]

Triple therapy (omeprazole, clarithromycin and metronidazole) is associated with a sensitive Helicobacter pylori (HP) eradication rate of over 90 per cent. As treatment failure is mainly due to poor patient compliance, satisfactory patient information is vital. Despite the high prevalence (29-40%) of metronidazole-resistant HP in Malmö, the eradication rate is over 90%. Clarithromycin-resistance among HP strains has increased in prevalence from 1 to 7% over the past four years, and always results in treatment failure. In order to avoid unnecessary antibiotic treatment, especially in cases of patients not responding to triple therapy, it is important to follow treatment up with, for example, the urea breath test.

Primary structure characterization of the photosystem II D1 and D2 subunits

Mass spectrometry techniques have been applied in a protein mapping strategy to elucidate the majority of the primary structures of the D1 and D2 proteins present in the photosystem II reaction center. Evidence verifying the post-translational processing of the initiating methionine residue and acetylation of the free amino group, similar to those reported for other higher plant species, are presented for the two subunits from pea plants (Pisum sativum L.). Further covalent modifications observed on the D1 protein include the COOH-terminal processing with a loss of nine amino acids and phosphorylation of Thr2. In addition, the studies reported in this paper provide the first definitive characterization of oxidations on specific amino acids of the D1 and D2 proteins. We believe that these oxidations, and to a much lesser extent the phosphorylations, are major contributors to the heterogeneity observed during the electrospray analysis of the intact subunits reported in the accompanying paper (Sharma, J., Panico, M., Barber, J., and Morris, H. R. (1997) J. Biol. Chem. 272, 33153-33157). Significantly, all of the regions that have been identified as those particularly susceptible to oxidation are anticipated (from current models) to be in close proximity to the redox active components of the photosystem II complex.

Effects of dihydroergotamine and sumatriptan on isolated human cerebral and peripheral arteries and veins

BACKGROUND

Pharmacological cerebral vasoconstriction has recently been suggested as treatment for patients with increased intracranial pressure (ICP) after severe traumatic brain lesions. Hypothetically, a moderate constriction of precapillary resistance vessels might be advantageous since it decreases intracapillary blood pressure, and a contraction of cerebral veins might effectively reduce intracranial blood volume and ICP. This report examines the in vitro effects of two vasoconstrictors, dihydroergotamine (DHE) and sumatriptan, which may be considered for treatment of increased ICP.

METHODS

The reactivity of isolated small human cerebral subcutaneous and omental arteries and veins were studied during exposure to different concentrations of DHE and sumatriptan.

RESULTS

Both sumatriptan and DHE induced concentration-dependent contractions in human cerebral arteries and veins and 50% of maximum contractions were obtained at significantly lower concentrations of DHE than of sumatriptan. The maximum contraction of cerebral arteries was significantly higher with sumatriptan than with DHE. Both drugs caused contractions of subcutaneous arteries at concentrations of 10(-7)-10(-6)M, which is within the therapeutic concentration range of sumatriptan, while no effect was obtained in omental vessels.

CONCLUSIONS

Both DHE and sumatriptan cause contraction of isolated human cortical arteries and veins at very low concentrations. The differences observed between the two drugs may be explained by the fact that DHE is an alpha-adrenergic as well as a 5-HT agonist while sumatriptan acts specifically on 5-HT receptors. The study supports the hypothesis underlying the use of DHE for the treatment of increased ICP in patients with severe traumatic brain lesions.

Relation between polymerase chain reaction findings and morphological changes during cytomegalovirus infection in transplanted lung

Cytomegalovirus (CMV) can be present as a latent or productive infection resulting in disease. The polymerase chain reaction (PCR) is a sensitive technique to document the presence of CMV (DNA). Negative reactions are indicative of its absence. The presence of CMV (DNA) was assessed longitudinally in 261 transbronchial lung biopsy (TBB) specimens from 37 patients over a 6-month period. The TBB specimens from six serologically CMV-negative recipients who received lungs from serologically CMV-negative donors never showed a positive CMV-PCR(DNA) reaction during the study. Based on a study of their TBB specimens, 10 serologically CMV-positive recipients who received lungs from serologically CMV-negative donors all developed a CMV-PCR(DNA)-positive reaction and five (50%) morphologically manifested CMV disease. The remaining 21 serologically CMV-positive recipients who received lungs from serologically CMV-positive donors all developed a CMV-PCR(DNA)-positive reaction and 15 (71%) developed CMV pneumonitis. The data show that development of a positive CMV-PCR(DNA) reaction in a TBB sample within the first month after transplantation indicates a greatly increased risk of developing CMV disease. In addition, a positive CMV-PCR(DNA) reaction preceded morphologically manifest disease on average by 2 weeks. Comparisons between TBB and bronchoalveolar lavage show the former to provide a more dependable template.

Treatment with an antioxidant inhibits vascular changes caused by circulating lymphocytes during acute lung rejection in dogs

BACKGROUND

Experiments were designed to evaluate the effect of treatment with an inhibitor of lipid peroxidation, H 290/51, on the interaction of lymphocytes and pulmonary arteries during acute lung rejection. It was hypothesized that inhibition of lipid peroxidation would reduce contractions of the pulmonary arteries to autogenous rejection-activated lymphocytes.

METHODS

Single-lung transplantation was performed in three groups of dogs: group 1 was maintained on immunosuppression for 8 days postoperatively; in group 2, immunosuppression was discontinued on postoperative day 5, so that rejection occurred on postoperative day 8; in group 3, immunosuppression was discontinued after 5 days, and the lipid peroxidation inhibitor H 290/51 was given orally for 3 days. The pulmonary arteries were removed, cut into rings, and suspended in organ chambers for measurement of isometric force.

RESULTS

Macrophage-depleted mononuclear cells (MNCs; lymphocytes) isolated from blood caused cell number-dependent contractions in rings of the pulmonary arteries from all dogs. In the rejecting dogs treated with H 290/51 (group 3), contractions to MNCs were significantly greater in rings without endothelium compared to rings with endothelium. Contractions to MNCs with or without endothelium were reduced by adding deteroxamine to the medium but not by adding superoxide dismutase and catalase.

CONCLUSIONS

The results of this study show that treatment with a lipid peroxidation inhibitor, H 290/51, does not prevent acute rejection of transplanted lungs. The treatment with the peroxidation inhibitor modifies contractions of the pulmonary arteries in response to rejection-activated lymphocytes, indicating that reactive oxidative metabolites may be involved in the vasoactive response resulting from this interaction.

The nicotine inhaler in smoking cessation

BACKGROUND

Nicotine replacement therapy has been shown to improve success rates in smoking cessation treatment. However, the available products cause adverse effects, which prevent some smokers from using them. A new method of delivering nicotine via inhaler supplies nicotine orally through inhalation from a plastic tube. This mode of delivering nicotine resembles smoking, as it includes handling and active inhalation.

OBJECTIVES

To assess the efficacy and safety of the nicotine inhaler as an aid in smoking cessation.

METHODS

A 1-year, randomized, double-blind, placebo-controlled study was conducted in a smoking cessation clinic. Two hundred forty-seven smokers who smoked at least 10 cigarettes per day and who had previously made a serious attempt to stop smoking using nicotine chewing gum were recruited through advertisements. Randomization to treatment or control conditions were made at the first group session, with 123 participants receiving nicotine inhalers and 124 receiving placebo inhalers. The inhalers were distributed at the second session and participants were allowed to use the inhalers for 6 months.

MAIN OUTCOME MEASURE

Biochemically verified continuous abstinence from smoking after 2 and 6 weeks and at 3, 6, and 12 months.

RESULTS

Significantly more participants who had used the nicotine inhalers were continuously abstinent compared with those who had used the placebo inhalers. The respective success rates after 12 months were 28% and 18% (P = .046). At 6 months, 20 participants (16%) in the nicotine group were still using the inhaler, compared with 4 (3%) in the control group (P < .001).

CONCLUSION

The nicotine inhaler was an effective smoking cessation aid that produced a few mild and transient adverse effects.

Inflammatory cells and activation markers in BAL during acute rejection and infection in lung transplant recipients: a prospective, longitudinal study

Acute rejection of the transplanted lung is a clinical problem, since it decreases graft survival and predisposes the patient to chronic rejection and obliterative bronchiolitis (OB). In an earlier study, we had indications that eosinophil cationic protein (ECP) from activated eosinophils and hyaluronan (HYA) from fibroblasts were associated with acute pulmonary rejection. This prospective longitudinal study was designed to investigate whether molecules from activated inflammatory cells in bronchoalveolar lavage (BAL) fluid could serve as clinically useful diagnostic markers for acute rejection. BAL fluid from 138 bronchoscopies performed in 10 single lung, four bilateral lung and five heart-lung transplant recipients were analysed. Nine patients were studied for a period of more than 1 yr (mean 13.4 months) after surgery. Differential cell counts were made from the BAL fluid. ECP, myeloperoxidase (MPO), HYA and interleukin-8 (IL-8) were used as indirect markers for activation and attraction of eosinophils, neutrophils and fibroblasts, respectively. Fifty four episodes of acute rejection were diagnosed. Two patients developed OB. Nine episodes of bacterial infection, 13 episodes of cytomegalovirus (CMV) pneumonitis, three of Pneumocystis carinii infection and one of respiratory syncytial virus (RSV) infection were diagnosed. The mean levels of ECP, MPO, HYA and IL-8 were all higher during rejection episodes, but differences were not statistically significant compared to no rejection, when the confounding factors of time, concomitant infection, and repeated measures in the same individual had been accounted for. We could not confirm that measurements of eosinophil cationic protein, myeloperoxidase, hyaluronan and interleukin-8 in bronchoalveolar lavage fluid can be used as diagnostic markers for acute rejection in the postoperative follow-up of lung transplant recipients.

Increased levels of circulating nitrates and impaired endothelium-mediated vasodilation suggest multiple roles of nitric oxide during acute rejection of pulmonary allografts

Experiments were designed to determine whether changes in pulmonary artery function could be reduced by treatment with a lipid peroxidation inhibitor (H 290/51) during acute rejection of pulmonary allografts. Single lung transplantation was performed in three groups of dogs: group 1 was maintained on immunosuppression for 8 days after operation (immunosuppressed, n = 5); in group 2, immunosuppression was discontinued on postoperative day 5, so that rejection occurred on postoperative day 8 (rejecting, n = 6); in group 3, immunosuppression was discontinued after 5 days, and the lipid peroxidation inhibitor H 290/51 (25 mg/kg) was given perorally for 3 days (rejecting + H 290/51, n = 6). Plasma nitric oxide (NO(x)) was measured by use of chemoluminescence. On postoperative day 8 rejection was observed in groups 2 and 3. Contractions to angiotensin I and endothelium-dependent relaxations to adenosine diphosphate were reduced in pulmonary arteries from rejecting lungs. Responses of rings from dogs treated with H 290/51 were similar to those from rejecting lungs. Rejection did not alter relaxations to exogenous nitric oxide. However, plasma levels of NO(x) increased significantly during rejection independently of treatment with H 290/51. Results of this study confirm that endothelium-dependent relaxation of pulmonary arteries is reduced during acute rejection of lung allografts. The result extends these observations to suggest that treatment with a lipid peroxidation inhibitor neither protects the pulmonary artery function nor affects levels of circulating NO(x). Therefore mechanisms other than lipid peroxidation participate in vascular changes associated with allograft rejection.

Saliva cotinine levels as a function of collection method

Saliva cotinine is commonly used to estimate nicotine intake but laboratories use different methods of collection. In three small trials, comparisons were made between (1) sugar vs. unstimulated saliva production (n = 29), (2) wax chewing vs. unstimulated production (n = 15) and (3) between two consecutive unstimulated saliva samples (n = 10). Sugar-stimulated saliva cotinine scores were 26% below unstimulated levels (p < 0.001); correlation between measures was high (r = 0.90; p < 0.001). Wax stimulated saliva yielded levels 6% below unstimulated (p < 0.05; correlation: r = 0.98; p < 0.001). No differences were observed between two unstimulated samples taken within a approximately 20-minute period (correlation: r = 0.99; p < 0.001). It is postulated that changes in salivary flow can account for the findings.

Insulin and amino acid infusion after cardiac operations: effects on systemic and renal perfusion

OBJECTIVE

The purpose of this study was to answer two questions: (1) Does a mixed amino acid infusion enhance systemic and renal perfusion in the early postoperative period after heart operations? (2) Does the addition of insulin (glucose-insulin-potassium solution) provide additional effects to those of an amino acid infusion?

METHODS

Thirty-three male patients undergoing coronary artery bypass grafting (mean age 65.9 +/- 1.2 years) were included in a prospective, controlled, randomized study. Eleven patients (AA group) received infusion of mixed amino acids (11.4 gm), 11 patients (AA + GIK group) received infusion of mixed amino acids (11.4 gm) and insulin solution (225 IU insulin, glucose with glucose clamp technique, and potassium), and 11 patients served as control subjects.

RESULTS

Amino acid infusion alone had no effect on systemic vascular resistance or cardiac index but increased renal blood flow 51% +/- 11% (from 114 +/- 13 to 172 +/- 24 ml.min-1.m-2 in one kidney, p < 0.05 vs the control group). Insulin solution in addition to amino acid infusion reduced systemic vascular resistance 24% +/- 3% (from 1280 +/- 85 to 960 +/- 57 dyn.sec.cm-5, p < 0.05 vs the control and AA groups) and increased cardiac index 13% +/- 3% (from 2.3 +/- 0.2 to 2.6 +/- 0.2 L.min-1.m-2, p < 0.05 vs the control and AA groups). Insulin had no significant additive effect on renal blood flow.

CONCLUSIONS

Our data imply that (1) infusion of mixed amino acids enhances renal blood flow after cardiac operations but has no effect on systemic perfusion and (2) the addition of insulin solution improves systemic perfusion. The combined treatment may potentially reduce the risk of renal hypoperfusion injury in the postoperative period after coronary artery bypass grafting.

Efficacy of a nicotine inhaler in smoking cessation: a double-blind, placebo-controlled trial

A non-combustible nicotine inhaler, administered orally, has been developed for treatment of smokers. The inhaler allows weaning from nicotine while maintaining partial reinforcement of the ritual/sensory phenomena of smoking. Subjects were randomly assigned to active (n = 112) and placebo (n = 111) groups. Some behavioral intervention occurred as a function of participation. Strict abstinence (primary outcome criterion) was defined by CO < or = 8 ppm with no slips allowed at any time and cotinine values < or = 14 at 1 year. Survival analysis showed active inhaler was superior to placebo (p < 0.01). Active vs. placebo success rates were: 63% vs. 47% (day 3), 46% vs. 28% (week 1), 36% vs. 19% (week 2), 33% vs. 16% (week 3), 29% vs. 14% (week 6), 24% vs. 10% (3 months), 17% vs. 9% (6 months) and 13% vs. 8% (1 year). chi 2 analyses were significant through 3 months but not at 6 months (p < 0.08) or 1 year. Craving was relieved with active inhalers at day 3 and week 1. Subjects averaged six inhalers/day. Cotinine levels were 57-61% of smoking levels. Common side effects included throat/mouth irritation and coughing. Failure was predicted by early slips. The inhaler is clearly useful for short-term smoking cessation with potential for long-term efficacy. Extended access to the inhaler and relapse prevention training could improve success rates. Another promising approach would be to combine the inhaler with a nicotine patch.

Activation of eosinophils and fibroblasts assessed by eosinophil cationic protein and hyaluronan in BAL. Association with acute rejection in lung transplant recipients

Lung transplantation has become an accepted therapy for end-stage lung disease. Acute rejection of the transplanted hung still remains a major clinical problem since it decreases graft survival. Eosinophil cationic protein (ECP) from activated eosinophils, hyaluronan (HYA) from fibroblasts, and circulating intercellular adhesion molecule 1 (1CAM-1) have been associated with acute rejection in kidney and liver grafts. We investigated whether these, as well as other molecules, were increased in acute rejection of lung allografts. Serum and BAL fluid from 38 bronchoscopies performed in 9 single lung, 2 bilateral lung, and 4 heart-lung transplant patients were studied. Differential cell counts were made from the BAL fluid. Levels of ECP, myeloperoxidase (MPO), and HYA were used as indirect markers for activation of eosinophils, neutrophils, and fibroblasts, respectively. In addition, levels of circulating ICAM-1, cVCAM-1, and cE-selectin were analyzed. Twenty-two episodes with acute rejection were diagnosed. Of these, 7 were minimal, 13 were mild, and 2 were of moderate character. We found increased levels of ECP and HYA in BAL fluid during mild acute rejection of the allograft. Numbers of eosinophils were also increased. Activation of neutrophils or neutrophil numbers were not significantly increased. Levels of circulating ICAM-1, cVCAM-1, and cE-selectin did not differ between the groups. This retrospective study shows that measurements of ECP and HYA can give information about the inflammatory process present during acute rejection in patients who have undergone lung transplants. Analysis of cCAMS, however, appears to be of limited value as markers for acute rejection.

Impaired endothelium-mediated vasodilatation in the peripheral vasculature of patients with acute pulmonary allograft rejection

BACKGROUND

Experimental studies have provided evidence that, during acute pulmonary allograft rejection, endothelial dysfunction occurs not only in the transplanted lung but also in arteries of organs native to the transplant recipient. We therefore tested the hypothesis that allograft rejection leads to the release of factors into the circulation that could affect the endothelial function in lung transplant recipients.

METHODS

Acetylcholine (10, 30, and 60 micrograms/min) and sodium nitroprusside (1, 3, and 6 micrograms/min) were infused into the brachial artery in nine transplant recipients (five single lung, one double lung, three heart-lung) 2 to 37 weeks after transplantation, during both acute rejection and rejection-free episodes. Changes in forearm blood flow were assessed with venous occlusion plethysmography. Plasma levels of interleukin-2, -6, and -8, endothelin-1, L-arginine, and asymmetric dimethylarginine were measured and correlated to rejection episodes.

RESULTS

The vasodilatory response to acetylcholine was significantly reduced during acute rejection compared with rejection-free episodes (percentage increase from basal flow: 156% +/- 21%, 395% +/- 65%, and 585% +/- 87% during rejection versus 272% +/- 75%, 633% +/- 113%, and 933% +/- 158% during absence of rejection, p < 0.05). No statistically significant difference was found between vasodilatory responses to nitroprusside during acute rejection and rejection-free episodes. Plasma levels of L-arginine, asymmetric dimethylarginine, interleukin-6, and endothelin-1 were not significantly altered during lung rejection.

CONCLUSIONS

These data indicate that a reversible peripheral decrease in endothelium-dependent vasodilatation occurs during acute rejection in lung transplant recipients. This result may be due to interactions among circulating cytokines and leukocytes activated by the rejection process and the endothelium.

Sumatriptan-induced cerebral vasoconstriction as treatment of experimental intracranial hypertension

BACKGROUND

Increased intracranial pressure (ICP) is a major cause of mortality in severe head injuries and pharmacologically induced cerebral vasoconstriction has been suggested as a possible treatment. In the present study a porcine model of increased ICP was utilized to study the changes in cerebral haemodynamics and energy metabolism induced by a selective 5-hydroxytryptamine1 agonist (sumatriptan).

METHODS

ICP was raised by inflation of two balloons covering both parieto-occipital regions extradurally. The animals were randomized into four groups receiving sumatriptan. 0.01 mg.kg-1 (A), 0.03 mg.kg-1 (B), 0.1 mg.kg-1 (C), and 0.5 mg.kg-1 (D) intravenously over 10 min. Measurements of cerebral blood flow (CBF), arterio-venous oxygen content difference (CavO2), and jugular venous pH (vpH) were performed 5, 20, 40, 60, and 75 min after start of the infusion. ICP, mean arterial pressure, and EEG were recorded continuously. Direct effects of sumatriptan were also compared in cortical arteries and veins in vitro.

RESULTS

Significant decreases in ICP were obtained in groups A, B, and C while group D exhibited a progressive increase in ICP. Significant reductions in CBF, increase in CavO2, and slowing of EEG were observed in groups B, C, and D. Sumatriptan caused moderate constriction of the arteries and a more pronounced dilatation of veins in vitro.

CONCLUSION

The results indicate that a low dose of sumatriptan has the potential to reduce a raised ICP. High doses of sumatriptan cause a further increase of ICP possibly by dilatation of intracerebral veins.

Identification of the heme adduct and an active site peptide modified during mechanism-based inactivation of rat liver cytochrome P450 2B1 by secobarbital

The olefinic barbiturate secobarbital (SB) is a sedative hypnotic known to be a relatively selective mechanism-based inactivator of rat liver cytochrome P450 2B1. Previous studies have demonstrated that such inactivation results in prosthetic heme destruction and irreversible drug-induced protein modification, events most likely triggered by P450 2B1-dependent oxidative activation of the olefinic pi-bond. However, the precise structure of the SB-modified heme and/or the protein site targeted for attack remained to be elucidated. We have now isolated the SB-heme adduct from P450 2B1 inactivated by [14C]SB in a functionally reconstituted system and structurally characterized it by electronic absorption spectroscopy and tandem collision-induced dissociation (CID), matrix-assisted laser desorption ionization on time of flight (MALDI-TOF), and liquid secondary ion mass spectrometry in the positive mode (+ LSIMS) as the N-(5-(2-hydroxypropyl)-5-(1-methylbutyl)barbituric acid)protoporphyrin IX adduct. The [14C]SB-modified 2B1 protein has also been isolated from similar inactivation systems and subjected to lysyl endopeptidase C (Lys-C) digestion and HPLC-peptide mapping. A [14C]SB-modified 2B1 peptide was thus isolated, purified, electrotransferred onto a poly-(vinylidene) membrane, and identified by micro Edman degradation of its first N-terminal 17 residues (S277NH(H)TEFH(H)ENLMISLL293) as the Lys-C peptide domain comprised of amino acids 277-323. This peptide thus includes the peptide domain corresponding to the distal helix I of P450 101, a region highly conserved through evolution, and which is known not only to flank the heme moiety but also to intimately contact the substrates. This finding thus suggests that SB-induced protein modification of P450 2B1 also occurs at the active site and, together with heme N-alkylation, contributes to the SB-induced mechanism-based inactivation of P450 2B1.

Cerebral vasoconstriction by indomethacin in intracranial hypertension. An experimental investigation in pigs

BACKGROUND

Uncontrolled increase in intracranial pressure is the most significant cause of mortality in patients with severe traumatic brain lesions, and the efficacy of common non-surgical treatments has been questioned. Pharmacologically induced cerebral vasoconstriction aiming at a decrease of cerebral blood volume and brain edema has recently been suggested as an alternative. Limited clinical experience with indomethacin as a cerebral vasoconstrictor has been reported but dose- or concentration-effect relationships were not investigated. In particular, there is a lack of data showing whether a therapeutic window exists in which risk of cerebral ischemia is minimized.

METHODS

In a porcine model of intracranial hypertension induced with two epidural balloons to a level of 26-28 mmHg, 18 animals were randomized into three groups receiving 0.1, 0.3, and 3.0 mg.kg-1.h-1 indomethacin, respectively, as an infusion during 80 min. Intracranial pressure, mean arterial blood pressure, and electrocortical activity were recorded continuously and measurements of cerebral blood flow, arteriovenous difference in oxygen content and cerebral venous pH were performed at 5, 20, 40, 60, and 75 min during and 10 min after the indomethacin infusion. Baseline measurements, performed before the indomethacin infusion, were used as an internal control. The infusions were pharmacokinetically designed to mimic the reported clinical conditions.

RESULTS

An 11% mean decrease in intracranial pressure during the infusion, but no effects on cerebral blood flow, arteriovenous difference in oxygen content, venous pH, and electrocortical activity were observed in the group of animals receiving 0.1 mg.kg-1.h-1. When the rate of infusion was 0.3 and 3.0 mg.kg-1.h-1, the decrease in intracranial pressure was 20 and 25%, respectively, but this was accompanied by a decrease in cerebral blood flow and venous pH, an increase in arteriovenous difference in oxygen content, and a slowing of the electrocortical activity. All changes were statistically significant.

CONCLUSIONS

Indomethacin, which is known to constrict precapillary resistance vessels, caused a decrease in intracranial pressure during experimental intracranial hypertension. This was accompanied by signs of cerebral ischemia when indomethacin was used in a dose that has previously been suggested for the treatment of increased intracranial pressure in patients.

Protective effects of an indenoindole antioxidant on coronary endothelial function after long-term storage

Experiments were designed to evaluate function of the endothelium and smooth muscle of coronary arteries following storage of hearts in cardioplegia containing an inhibitor of lipid peroxidation (H 290/51, cis-7-methyl-9-methoxy-5,5a, 6,10b tetrahydroindeno [2,1-b] indole). Canine hearts were perfused with crystalloid cardioplegia (Plegisol, 15 ml/kg, 4 degrees C) and left circumflex arteries were isolated and studied either immediately (group I, n = 6), or after storage of the hearts at 4 degrees C for 10 (group II, n = 6) or 24 hr with (group III, n = 6) or without (group IV, n = 6) addition of H 290/51. The final concentration of H 290/51 was 1 mumol/L. Arteries were removed, cut into rings, and suspended in organ chambers for measurements of isometric force. In selected rings, the endothelium was removed in order to study the function of the smooth muscle. In order to discriminate effects of ischemia/reperfusion and protective properties on coronary endothelium or smooth muscle, drugs with different mechanisms were used. The function of the endothelium were studied with the alpha 2-adrenergic agonist UK 14,304, bradykinin and A 23187. The smooth muscle function were studied with isoproterenol and nitric oxide. Endothelium-dependent relaxations to the alpha 2-adrenergic agonist UK 14,304 and bradykinin, but not to A 23187, were reduced significantly in arteries from hearts stored for 24 hr in cardioplegic solution alone. Relaxations of arteries from hearts stored for 24 hr with H 290/51 were comparable to those arteries from hearts that were not stored. Endothelium-independent relaxations to isoproterenol and nitric oxide among the different groups were comparable. These results suggest that storage of canine hearts with crystalloid cardioplegia selectively inhibits endothelium-dependent relaxations mediated by receptor activation. Inhibition of lipid peroxidation with H 290/51 preserves these relaxations and may therefore represent a therapeutic alternative to preserve hearts used for transplantation.

Effects of dihydroergotamine on cerebral circulation during experimental intracranial hypertension

Different cerebral vasoconstrictors have recently been suggested for the treatment of raised intracranial pressure (ICP), in patients with severe traumatic brain lesions. Such treatment may be associated with severe side effects. A porcine model simulating an intracranial mass lesion was utilized to examine the haemodynamic cerebral effects of dihydroergotamine (DHE), a recently introduced pharmacological treatment for raised intracranial pressure. Intracranial hypertension was induced by inflation of two tonometric gastric balloons placed extradurally covering the parieto-occipital region bilaterally. The animals were randomized into one group with six animals receiving 1.0 mg of DHE i.v. followed by a continuous infusion of 0.2 mg/h (high dose) and another group of six animals receiving 0.15 mg i.v. followed by 0.03 mg/h (low dose). Measurements of cerebral blood flow (CBF) and arterio-venous difference in oxygen content (CaVO2) were performed by 5, 20 and 60 min after the DHE infusion. Intracranial pressure (ICP), mean arterial blood pressure (MAP) and cerebral electrical activity (EEG) were recorded continuously. In both groups infusion of DHE caused a lasting decrease in ICP probably achieved mainly by a decrease in cerebral blood volume due to constriction of both arterial and venous capacitance vessels. In the group treated with high-dose DHE, but not in that given low-dose DHE, a progressive increase in CaVO2, a fall in jugular venous pH and an increase in EEG delta activity were observed indicating cerebral hypoxia. The study supports the view that DHE may be a valuable tool in the pharmacological treatment of increased ICP in traumatic brain lesions but underscores the importance of a proper dosage.

A porcine model for evaluation of cerebral haemodynamics and metabolism during increased intracranial pressure

In patients with severe head injuries raised intracranial pressure (ICP) constitutes the most important cause of mortality. Several new therapies for increased ICP have recently been suggested and it is of importance to study the physiological effects of these treatments in animal experiments during steady state conditions. A porcine model for evaluation of cerebral haemodynamics and metabolism during increased ICP is presented. Intracranial hypertension was induced by inflation of two tonometric gastric balloons placed extradurally covering a major part of the parietooccipital region bilaterally. The distribution of the blood flow supplied by the carotid artery used for the cerebral blood flow (CBF) measurements was studied by intraarterial (i.a.) injection of 99mTc-HMPAO. The measurements showed that following ligation of the external carotid and the occipital artery no accumulation of tracer substance occurred in extracranial tissues during normal or increased ICP. Cerebral physiological variables (CBF, Cavo2, and ICP) were measured 5, 20 and 60 min after induction of intracranial hypertension. The results confirm that the experimental situation gives a reproducible increase in ICP (25-28 mm Hg) and that the physiological variables remain stable during the period of intracranial hypertension. We conclude that the model simulates the effects of an acute intracranial focal mass and is well suited for the evaluation of different pharmacological therapies of increased ICP.

Alpha-ketoglutarate for myocardial protection in heart surgery

A low myocardial content of alpha-ketoglutarate during heart surgery might aggravate ischaemic injury. 24 men undergoing coronary surgery participated in a randomised controlled study. 28 g alpha-ketoglutarate was added to blood cardioplegia for intermittent antegrade intracoronary perfusion in 13 cases. alpha-ketoglutarate reduced the appearance in blood of the ischaemic markers creatine kinase MB and troponin T (at 4 h after release of aortic cross-clamp; median [95% CI] 49 [37-60] micrograms/L in controls vs 32 [27-37] micrograms/L for creatine kinase MB, 2.0 [1.2-2.8] vs 1.1 [0.8-1.4] micrograms/L for troponin T). These findings signify attenuated ischaemic injury, possibly secondary to enhanced myocardial oxidative capacity.

Improved long-term preservation of the coronary vasculature with University of Wisconsin solution

Experiments were designed to investigate coronary vascular function after prolonged cold storage of isolated rat hearts, using University of Wisconsin (UW) solution. Hearts perfused with crystalloid cardioplegic solution (Plegisol) were used as controls. After perfusion with 10 ml at 4 degrees C, hearts were stored for 1 or 10 hours in the respective solutions at 4 degrees C. To evaluate coronary vascular function after perfusion and storage, endothelium-dependent vasodilation was induced with 5-hydroxytryptamine (5-HT) and smooth muscle-dependent dilation with nitroglycerin (GTN). After perfusion only, or perfusion plus 1-hour storage, there was no intergroup difference in response to 5-HT and GTN. After 10-hour storage the vasodilatory response to 5-HT was abolished in the Plegisol group and slight vaso-constriction was observed, whereas in the UW group the vasodilatory effect of 5-HT persisted. The findings suggest that UW solution may be more favorable for prolonged cardiac preservation, as the coronary vascular reactivity was less affected.

A novel anti-oxidative agent improves recovery of the heart after cardiac arrest

Experiments were designed to determine whether adding a synthetic anti-oxidative agent H 290/51 (cis-7methyl-9-methoxy-5,5 a,6,10 b-tetrahydroindeno [2,1-b] indole), to a crystalloid cardioplegic solution was beneficial for myocardial recovery and coronary reactivity in isolated rat hearts after six hours cold arrest. Two groups of hearts were single-flush perfused using the Langendorff technique (10 ml at 4 degrees C) with either Plegisol (St. Thomas' Hospital Solution) (n = 6) or Plegisol with H 290/51 (n = 6) added to a final concentration of 1 mummol/L. The heart were then stored for six hours in the respective solution at 4 degrees C. A third group of hearts (n = 6) were single-flush with Plegisol and reperfusion was immediately started (the 'non-stored' group). Before and after the arrest phase the hearts were perfused at constant pressure with Krebs-Henseleit bicarbonate buffer. To evaluate coronary vascular function, endothelium-dependent vasodilatation was induced with 5-hydroxy-tryptamine (5-HT) and smooth-muscle relaxation with nitroglycerin (GTN). Myocardial contractility after 30 min reperfusion, measured as left-ventricular developed pressure (LVDP), was significantly improved in hearts in the Plegisol+H 290/51 group compared to hearts in the Plegisol group (LVDP 89 +/- 8.5% vs 57.2 +/- 10.7% of prearrest values; p < 0.05). LVDP in hearts receiving Plegisol+H 290/51 was comparable to non-stored hearts (88.2 +/- 1.3%). The vasodilatory response to GTN was significantly reduced in hearts perfused with plain Plegisol (p < 0.05) but not in hearts receiving Plegisol+H 290/51 or in the non-stored hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of thiopental on cerebral blood flow, and its relation to plasma concentration, during simulated induction of anaesthesia in a porcine model

The reversible effect of an induction dose of thiopental on the cerebral blood flow (CBF) was characterized by repeated 133Xe washout measurements during stable physiological conditions in anaesthetized pigs. A thiopental effect corresponding to induction of light and transient anaesthesia was confirmed by electroencephalography (EEG). The concentration (arterial plasma) -effect (-% CBF) relationship of thiopental was estimated using a sigmoidal Emax model. The injection caused a rapid 36 +/- 4.5% (mean +/- s.d.) drop in CBF, with return to baseline by 80 min. According to the pharmacodynamic model, the maximal effect of thiopental (Emax) in this experimental set-up was a 58% lowering of the CBF and the concentration at half-maximal effect (EC50) was 25 micrograms.ml-1. This study provides a complete characterization of the effect of thiopental on the CBF, including the time-course and concentration-effect relationship. A comparison to limited data in the literature suggests that the findings in the pigs constitute a fair approximation of the action of thiopental during the clinical induction of anaesthesia.

Subfractional analysis of cyanobacterial membranes and isolation of plasma membranes by aqueous polymer two-phase partitioning

The present work demonstrates that partition in aqueous polymer two-phase systems offers a rapid method for separation and isolation of thylakoid, plasma, and outer membranes from cyanobacteria. Pure plasma membranes from Phormidium laminosum can be isolated by this method within 3 h, starting with total membranes obtained by French press treatment of the cyanobacterial cells. The isolated plasma membranes have a broad density profile, giving rise to three subpopulations. The main fraction has the same density as the abundant thylakoid membranes. This fraction has not been resolved in previous separations based on sucrose gradient centrifugation, which is the only method previously used for isolation of cyanobacterial plasma membranes. Another advantage of the aqueous polymer two-phase system is that it can handle large quantities of starting material, which is essential to obtain a satisfactory yield since plasma membranes constitute only a very small fraction of the total membrane content in a cyanobacterial cell. The isolation procedure results in a pure plasma membrane preparation with retained cytochrome c oxidase activity. The results also point to the possibility of a lateral heterogeneity in the organization of the cyanobacterial plasma membrane.

Glucose-insulin-potassium (GIK) prevents derangement of myocardial metabolism in brain-dead pigs

Brain death is associated with neuroendocrine changes resulting in reduced myocardial glycogen content. The purpose of this study was to investigate the effects of glucose-insulin-potassium (GIK), on myocardial metabolism in brain-dead pigs. Sixteen brain-dead pigs were given GIK infusion (n = 8), or Ringer solution (n = 8). At end-point (7 h post brain death) arterial concentrations and myocardial arteriovenous (a-v) concentration differences of glucose, lactate and free fatty acids (FFA) were assessed, and myocardial biopsy specimens were taken from the right atrium and left ventricle. Biopsies were also taken from five normal pigs. Myocardial glycogen content in the GIK group was significantly higher compared to the control group, but comparable to the non-brain-dead animals. There was a higher and significant myocardial uptake of glucose and lactate in the GIK group compared to the controls. Plasma levels of FFA were significantly lower in the GIK group, and the myocardial uptake of FFA was 5 times higher in the control group compared to the GIK group. There were no significant differences in hemodynamic variables among the groups. In conclusion, intravenous supply of GIK to brain-dead pigs results in increased myocardial glycogen content and seems to prevent abnormal myocardial metabolism, which may have clinical implications for the myocardial protection of donor hearts.

A double-blind trial of a nicotine inhaler for smoking cessation

OBJECTIVE

To evaluate the efficacy of a new nicotine inhaler system for smoking cessation.

DESIGN

A 1-year, randomized, double-blind, placebo-controlled study.

SETTING

Medical outpatient clinic with physicians experienced in smoking cessation assistance.

SUBJECTS

A total of 286 volunteers who smoked at least 10 cigarettes daily recruited through a local newspaper.

INTERVENTION

Subjects were randomly allocated to nicotine inhalers (n = 145) or placebo (n = 141) to be used for 3 months followed by tapering for 3 months in the context of minimal levels of advice and support.

MAIN OUTCOME MEASURE

Continuous smoking abstinence at weeks 6, 12, 24, and 52, verified by measurements of carbon monoxide in expired air.

RESULTS

Continuous smoking abstinence was significantly higher for the active nicotine inhaler group compared with the placebo inhaler group. The respective success rates were 28% and 12% after 6 weeks, 21% and 9% after 12 weeks, 17% and 8% after 6 months, and 15% and 5% after 1 year (P = .02 to .001). The mean nicotine substitution based on cotinine determinations after 2 weeks was 43% (SD, 45%) of smoking levels. The treatment was well tolerated, and no serious adverse events were reported.

CONCLUSIONS

In this setting the nicotine inhaler appeared safe to use and increased success rates of smoking cessation attempts.

Six-hour preservation of the isolated working rat heart improved with University of Wisconsin solution

University of Wisconsin (UW) solution was compared with modified St. Thomas cardioplegic solution for 6-hour preservation of isolated working rat hearts. The hearts (9 in each group) were arrested with the respective solution and stored, still cannulated, for 6 hours at 4 degrees C. After retrograde reperfusion for 30 minutes, antegrade perfusion was begun at constant left atrial and aortic pressures. Following 25 minutes of antegrade perfusion the hemodynamic recovery of the UW-preserved hearts was superior to that of the other hearts (cardiac output 46.0 +/- 4.8% of the preischemic control values in the UW group and 10.0 +/- 6.0% in the St. Thomas group, p < 0.01). The adenosine triphosphate content was significantly higher in the UW-preserved hearts (18.8 +/- 0.9 vs. 14.7 +/- 1.6 mumol/g dry weight, p < 0.05). No significant intergroup difference was found in aspartate aminotransferase leak or tissue glycogen. The study demonstrated both better function and enhancement of high-energy phosphates with UW solution vs. modified St. Thomas solution in isolated rat hearts, although without difference in enzyme leakage or tissue glycogen, after 6-hour preservation.

Ketamine and midazolam decrease cerebral blood flow and consequently their own rate of transport to the brain: an application of mass balance pharmacokinetics with a changing regional blood flow

Mass balance pharmacokinetics, with simultaneous blood sampling from an artery and the internal jugular vein, was used to characterize the cerebral uptake of ketamine, norketamine, and midazolam in normoventilated pigs. Intravenous injections of ketamine or midazolam decreased the cerebral blood flow (CBF) by one third, as measured by intermittent 133Xe washout. By means of pharmacodynamic models, the effects on the CBF could be predicted from the arterial drug concentrations. The high-resolution CBF vs. time curves thus generated allowed the calculation of cerebral drug levels from arterio-venous concentration gradients in spite of a continuously changing regional blood flow. By their effects on the CBF, ketamine and midazolam decrease their own rate of transport to the brain, the immediate 30-35% drops in CBF giving similar reductions in initial net influx of drug. Physiological pharmacokinetic models assuming a constant regional blood flow are therefore not appropriate. Under clinical conditions, the CBF is determined mainly by the effects of the anesthetics and by the arterial CO2 tension. CBF changes in either direction influence the transport of drugs to the brain and may consequently result in impaired or exaggerated drug effects.

A porcine model for sequential assessments of cerebral haemodynamics and metabolism

We present a physiologically stable porcine model designed for sequential assessments of pharmacological effects on mean hemispheric cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2) at sustained normocapnia. The dynamic influence of continuously administered fentanyl (0.040 mg.kg-1.h-1 i.v.), nitrous oxide (70%) and pancuronium (0.30 mg.kg-1.h-1 i.v.) on these variables was studied in eight normoventilated pigs. CBF was reliably assessable at 10-min intervals by clearance of intra-arterially injected 133Xe, monitored by an extracranial scintillation detector. CMRO2 was calculated from CBF and the simultaneously measured cerebral arteriovenous difference in blood oxygen content. The intracerebral distribution of a contrast medium injected into the external and internal carotid arteries was studied by angiography, and the cerebral venous outflow was investigated by measurements of the distribution of an intra-arterially administered non-diffusible tracer, [99mTc]pertechnetate, to the internal and external jugular veins. After a 3-h equilibration period, CBF and CMRO2 were determined on six occasions over a study period lasting 1 h 40 min. The mean ranges of these variables were 56-60 and 1.9-2.0 ml.100 g-1.min-1, respectively. We conclude that the model enables repeated assessments of CBF and CMRO2 under stable physiological background conditions and thus valid cerebral pharmacodynamic investigations of drugs given for anaesthesia.

Ultrastructural and biochemical characterization of a Synechocystis 6803 mutant with inactivated psbA genes

A constructed Synechocystis 6803 mutant with a deletion of the three psbA genes was subjected to ultrastructural and biochemical characterization. This D1-depleted mutant also lacks the D2 protein and the chlorophyll a-binding protein CP-47. A general ultrastructural comparison between the wild type and the mutant did not reveal any major changes in cell appearance. We found by freeze-fracture analysis that approximately 60% of the endoplasmic face particles found in the wild-type thylakoids were missing in the mutant. A corresponding increase in protoplasmic face particles in the mutant thylakoids may represent a subcomplex of those photosystem II (PS II) polypeptides which accumulate in the absence of the D1 protein. Correlation of the PS I:PS II ratio with freeze-fracture data indicates that there is only one reaction center in each PS II freeze-fracture particle. Fluorescence measurements show that the CP-43 polypeptide in the mutant binds chlorophyll and that it may be connected to the phycobilisomes. Excitation energy can be transferred from the phycobilisomes to photosystem I in the absence of the photosystem II reaction center heterodimer and CP-47. This suggests that exciton transfer to photosystem I is mediated either directly by a terminal phycobilisome transmitter or via CP-43.

Effects of insulin on myocardial uptake of branched chain amino acids soon after cardiac operations

Infusion of insulin-glucose-potassium is used to support the failing heart after cardiac operations. Although the effects on myocardial uptake of carbohydrates and lipids have been described, the effects on myocardial extraction of amino acids are unknown. This study was undertaken to clarify the effect of insulin-glucose-potassium on the pattern of amino acid uptake/release in myocardial and skeletal muscle after coronary operations. The amino acid uptake/release of the heart and of the leg was studied in 18 patients 1 hour after coronary bypass operations. The patients were randomized to treatment with 25 U of fast-acting insulin as a bolus injection followed by a continuous infusion of 1 U/kg body weight for 1 hour, or to serve as control patients. The hyperinsulinemic "clamp" technique was used to keep blood glucose unchanged during the study. In the insulin-treated group, the arterial concentration of 17 of 22 individual amino acids, including the three branched chain amino acids, decreased, the remainder being unchanged. The amino acid uptake/release of the leg was unchanged. The net myocardial uptake of leucine and isoleucine shifted to a no-uptake/no-release in the insulin-treated group, whereas the no-uptake/no-release of tyrosine and phenylalanine turned into a significant release. A positive correlation was observed between arterial concentration and myocardial uptake/release of the three branched chain amino acids. It is suggested that insulin, by lowering the arterial concentration of leucine and isoleucine, inhibited the myocardial uptake of these amino acids. This may have a negative effect on postoperative myocardial protein balance suggested by the release of tyrosine and phenylalanine.

Calcified leiomyosarcoma simulating uterine myoma in a patient with long-standing anaemia

A case of small bowel leiomyosarcoma in a 75-year-old woman is reviewed. The patient had an unexplained anaemia with occult blood in the faeces for at least 15 years. The value of different radiological investigations in patients with suspected gastrointestinal bleeding is discussed. The possible significance of calcifications visible on plain abdominal films is emphasized.

Trauma metabolism and the heart. Uptake of substrates and effects of insulin early after cardiac operations

In a controlled, randomized study the myocardial uptake/release of individual free fatty acids, glucose, lactate, pyruvate, alanine, and glycerol was studied 1 hour after completion of coronary operations. The effects of insulin were evaluated by means of a hyperinsulinemic "clamp" technique. No significant uptake of free fatty acids was found despite markedly elevated arterial concentrations (mean +/- standard error of the mean, 2.01 +/- 0.19 mmol.L-1), oleic acid, together with palmitic and linoleic acid, constituting 80% of the total plasma free fatty acid level. Insulin treatment (1 unit.kg bw-1.hr-1) prevented a further increase of the plasma free fatty acid level, observed concomitantly in the control group. Insulin affected all individual free fatty acids similarly. Changes in plasma free fatty acid levels occurring during the study and the corresponding myocardial uptake correlated (rS = 0.50 to 0.81). No significant uptake or release of glucose, lactate pyruvate, and glycerol occurred, whereas a myocardial release of alanine was seen. The heart and the concomitant leg uptake/release of glucose (rS = 0.40, p less than 0.05) and lactate (rS = 0.67, p less than 0.01) correlated. A substantial uptake of glucose was achieved and a more positive myocardial balance was obtained for alanine, lactate, and pyruvate with insulin. The changes in heart and the concomitant leg uptake/release correlated (glucose, rS = 0.62, p less than 0.01; lactate, rS = 0.64, p less than 0.01; pyruvate, rS = 0.71, p less than 0.01). It is concluded that the myocardial uptake of substrates during the first hours after coronary surgery is markedly abnormal with no uptake of free fatty acids or carbohydrates. These changes can be explained to some extent by the insulin resistance of trauma metabolism and can be modified by insulin treatment.

Trauma metabolism and the heart: studies of heart and leg amino acid flux after cardiac surgery

Flux of plasma amino acids was measured across the heart and the leg (reflecting mainly skeletal muscle) in 18 patients 1 hour after completion of aorto-coronary bypass surgery. There was a net loss of amino acids from the leg (-324.9 +/- 39 nmol/min/100 ml tissue) while amino acid flux across the heart was not statistically different from zero. There were however positive intertissue correlations between leg and myocardial flux of tyrosine and most other amino acids, suggesting that protein metabolism of both tissues were affected in the same catabolic direction by the trauma response. Alanine and glutamine accounted for 50% of the amino acid release from the leg, which is in accordance with observations in association with other types of trauma. Alanine and glutamine also dominated amino acid release from the heart. Glutamate and aspartate were taken up by both tissues. The principal difference between the tissues was a myocardial uptake of leucine and isoleucine, in contrast to a leg release.

[Investigation of accidents by the Special Inspection for Electrical Electrical Medical Equipment]

The article reviews the responsibilities of the Special Inspection for Electrical Medical Equipment, STEM, with emphasis on investigations of accidents and near-accidents in connection with the use of technical equipment. It stresses the obligation to report to STEM immediately. The reported accidents for the period 1980-1988 are given in table 1, and are discussed. Norwegian statistics are compared with both American and Scandinavian data and reference is made to the international standardization on technical medical equipment.