Outpatient treatment with concomitant vaccine-boosted convalescent plasma for patients with immunosuppression and COVID-19

Although severe coronavirus disease 2019 (COVID-19) and hospitalization associated with COVID-19 are generally preventable among healthy vaccine recipients, patients with immunosuppression have poor immunogenic responses to COVID-19 vaccines and remain at high risk of infection with SARS-CoV-2 and hospitalization. In addition, monoclonal antibody therapy is limited by the emergence of novel SARS-CoV-2 variants that have serially escaped neutralization. In this context, there is interest in understanding the clinical benefit associated with COVID-19 convalescent plasma collected from persons who have been both naturally infected with SARS-CoV-2 and vaccinated against SARS-CoV-2 ("vax-plasma"). Thus, we report the clinical outcome of 386 immunocompromised outpatients who were diagnosed with COVID-19 and who received contemporary COVID-19-specific therapeutics (standard-of-care group) and a subgroup who also received concomitant treatment with very high titer COVID-19 convalescent plasma (vax-plasma group) with a specific focus on hospitalization rates. The overall hospitalization rate was 2.2% (5 of 225 patients) in the vax-plasma group and 6.2% (10 of 161 patients) in the standard-of-care group, which corresponded to a relative risk reduction of 65% (P = 0.046). Evidence of efficacy in nonvaccinated patients cannot be inferred from these data because 94% (361 of 386 patients) of patients were vaccinated. In vaccinated patients with immunosuppression and COVID-19, the addition of vax-plasma or very high titer COVID-19 convalescent plasma to COVID-19-specific therapies reduced the risk of disease progression leading to hospitalization.IMPORTANCEAs SARS-CoV-2 evolves, new variants of concern (VOCs) have emerged that evade available anti-spike monoclonal antibodies, particularly among immunosuppressed patients. However, high-titer COVID-19 convalescent plasma continues to be effective against VOCs because of its broad-spectrum immunomodulatory properties. Thus, we report clinical outcomes of 386 immunocompromised outpatients who were treated with COVID-19-specific therapeutics and a subgroup also treated with vaccine-boosted convalescent plasma. We found that the administration of vaccine-boosted convalescent plasma was associated with a significantly decreased incidence of hospitalization among immunocompromised COVID-19 outpatients. Our data add to the contemporary data providing evidence to support the clinical utility of high-titer convalescent plasma as antibody replacement therapy in immunocompromised patients.

Comparable outcomes of outpatient remdesivir and sotrovimab among high-risk patients with mild to moderate COVID-19 during the omicron BA.1 surge

Studies conducted prior to SARS-CoV-2 Omicron demonstrated that sotrovimab and remdesivir reduced hospitalization among high-risk outpatients with mild to moderate COVID-19. However, their effectiveness has not been directly compared. This study examined all high-risk outpatients with mild to moderate COVID-19 who received either remdesivir or sotrovimab at Mayo Clinic during the Omicron BA.1 surge from January to March 2022. COVID-19-related hospitalization or death within 28 days were compared between the two treatment groups. Among 3257 patients, 2158 received sotrovimab and 1099 received remdesivir. Patients treated with sotrovimab were younger and had lower comorbidity but were more likely to be immunocompromised than remdesivir-treated patients. The majority (89%) had received at least one dose of COVID-19 vaccine. COVID-19-related hospitalization (1.5% and 1.0% in remdesivir and sotrovimab, respectively, p = .15) and mortality within 28 days (0.4% in both groups, p = .82) were similarly low. A propensity score weighted analysis demonstrated no significant difference in the outcomes between the two groups. We demonstrated favorable outcomes that were not significantly different between patients treated with remdesivir or sotrovimab.

Real-world Clinical Outcomes of Bebtelovimab and Sotrovimab Treatment of High-risk Persons With Coronavirus Disease 2019 During the Omicron Epoch

Background

Antispike monoclonal antibodies are recommended for early treatment of high-risk persons with mild to moderate coronavirus disease 2019 (COVID-19). However, clinical outcomes of their use during the severe acute respiratory syndrome coronavirus 2 Omicron wave are limited.

Methods

This is a descriptive retrospective study of high-risk adult patients who received treatment with sotrovimab (January 1-March 20, 2022) or bebtelovimab (March 21-April 30, 2022). The primary outcome was the proportion of patients who progressed to severe outcome within 30 days after receiving antispike-neutralizing monoclonal antibody infusion.

Results

A total of 3872 high-risk patients (median age, 62.7 years; 41.1% male) with mild to moderate COVID-19 received sotrovimab (n = 2182) or bebtelovimab (n = 1690). Among sotrovimab-treated patients, the most common comorbidities were an immunosuppressed condition (46.7%), hypertension (38.2%), and diabetes (21.2%). The rates of severe outcome, intensive care unit (ICU) admission, and mortality were 2.2%, 1.0%, and 0.4%, respectively, after sotrovimab infusion. Among bebtelovimab-treated patients, the most common comorbidities were hypertension (42.7%), diabetes (17.1%), and an immunosuppressed condition (17.0%). The rates of severe disease, ICU admission, and mortality were 1.3%, 0.5%, and 0.2%, respectively, after bebtelovimab infusion. Older age, immunosuppressed status, and several comorbidities were associated with severe disease progression, while COVID-19 vaccination was associated with lower risk. No anaphylaxis was reported during monoclonal antibody infusion.

Conclusions

This real-world analysis of a large cohort of high-risk patients demonstrates low rates of severe disease after treatment with sotrovimab during the era dominated by Omicron B.1.1.529 and after treatment with bebtelovimab during the era dominated by BA.2 and Omicron subvariants.

Outcomes of Bebtelovimab Treatment is Comparable to Ritonavir-boosted Nirmatrelvir among High-Risk Patients with Coronavirus Disease-2019 during SARS-CoV-2 BA.2 Omicron Epoch

The effectiveness of bebtelovimab in real-world settings has not been assessed. In this retrospective cohort study of 3607 high-risk patients, bebtelovimab was used more commonly than nirmatrelvir-ritonavir for treatment of coronavirus disease 2019 (COVID-19) among older patients, immunosuppressed patients, and those with multiple comorbid conditions. Despite its use in patients with multiple comorbid conditions, the rate of progression to severe disease after bebtelovimab (1.4% [95% confidence interval, 1.2%–1.7%]) was not significantly different from that for nirmatrelvir-ritonavir treatment (1.2% [.8%–1.5%]). Our findings support the emergency use authorization of bebtelovimab for treatment of COVID-19 during the Omicron epoch dominated by BA.2 and subvariants.

Patient Perspectives on Anti-spike Monoclonal Antibody Therapy for Mild to Moderate Coronavirus Disease-2019

Anti-spike monoclonal antibodies emerged as effective early treatment of high-risk individuals with mild-to-moderate COVID-19. Although their clinical and safety outcomes have been reported, patient perspectives of these experimental therapies have not been evaluated. In this survey participated by 644/2412 (26.7% response) individuals evaluated for anti-spike monoclonal antibody therapies, the majority of 523 patients who received the antibody infusion were very satisfied with their overall patient experience, the quality of care provided, and various aspects of medical care. They voiced satisfaction with the communication with providers before and during treatment, including education provided about monoclonal antibody treatment, the potential benefits and adverse effects, detailed instructions on the process of infusion, and safety protocols employed at the infusion facilities. Nearly a quarter (23.6%) of 121 patients who declined therapy indicated they would accept treatment should it be offered again. These patient perspectives may be used to guide healthcare facilities and providers in optimizing the care provided to high-risk outpatients with COVID-19.

Intravenous bamlanivimab use associates with reduced hospitalization in high-risk patients with mild to moderate COVID-19

BACKGROUNDClinical data to support the use of bamlanivimab for the treatment of outpatients with mild to moderate coronavirus disease-19 (COVID-19) are needed.METHODS2335 Patients who received single-dose bamlanivimab infusion between November 12, 2020, and February 17, 2021, were compared with a propensity-matched control of 2335 untreated patients with mild to moderate COVID-19 at Mayo Clinic facilities across 4 states. The primary outcome was the rate of hospitalization at days 14, 21, and 28.RESULTSThe median age of the population was 63 years; 47.3% of the bamlanivimab-treated cohort were 65 years or more; 49.3% were female and 50.7% were male. High-risk characteristics included hypertension (54.2%), BMI greater than or equal to 35 (32.4%), diabetes mellitus (26.5%), chronic lung disease (25.1%), malignancy (16.6%), and renal disease (14.5%). Patients who received bamlanivimab had lower all-cause hospitalization rates at days 14 (1.5% vs. 3.5%; risk ratio [RR], 0.41), 21 (1.9% vs. 3.9%; RR, 0.49), and 28 (2.5% vs. 3.9%; RR, 0.63). Secondary exploratory outcomes included lower intensive care unit (ICU) admission rates at days 14 (0.14% vs. 1%; RR, 0.14), 21 (0.25% vs.1%; RR, 0.25), and 28 (0.56% vs.1.1%; RR. 0.51) and lower all-cause mortality at days 14 (0% vs. 0.33%), 21 (0.05% vs. 0.4%; RR,0.13), and 28 (0.11% vs. 0.44%; RR, 0.26). Adverse events were uncommon with bamlanivimab, occurring in 19 of 2355 patients, and were most commonly fever (n = 6), nausea (n = 5), and lightheadedness (n = 3).CONCLUSIONSAmong high-risk patients with mild to moderate COVID-19, treatment with bamlanivimab was associated with a statistically significant lower rate of hospitalization, ICU admission, and mortality compared with usual care.FUNDINGMayo Clinic.

Real-World Clinical Outcomes of Bamlanivimab and Casirivimab-Imdevimab among High-Risk Patients with Mild to Moderate Coronavirus Disease 2019

BACKGROUND

Bamlanivimab and casirivimab-imdevimab are authorized for treatment of high-risk patients with mild to moderate coronavirus disease-2019 (COVID-19). We compared the outcomes of patients who received these therapies to identify factors associated with hospitalization and other clinical outcomes.

METHODS

Adult patients who received monoclonal antibody from November 19, 2020 to February 11, 2021 were selected and divided into those who received bamlanivimab (n=2747) and casirivimab-imdevimab (n=849). The 28-day all-cause and COVID-19-related hospitalizations were compared between the groups.

RESULTS

The population included 3596 patients; median age was 62 years; and 50% were female. All had ≥1 medical comorbidity; 55% had multiple comorbidities. All cause- and COVID-19-related hospitalization rates at 28 days were 3.98% and 2.56%, respectively. After adjusting for medical comorbidities, there was no significant difference in all cause- and COVID-19-related hospitalization rates between bamlanivimab and casirivimab-imdevimab (adjusted HR, 1.4, 95% CI 0.9-2.2 and 1.6, 95% CI 0.8-2.7, respectively). Chronic kidney, respiratory and cardiovascular diseases, and immunocompromised status were associated with higher likelihood of hospitalization.

CONCLUSION

This observational study on the use of bamlanivimab and casirivimab-imdevimab in high-risk patients showed similarly low rates of hospitalization. The number and type of medical comorbidities are associated with hospitalizations after monoclonal antibody treatment.

Association of Intravenous Bamlanivimab Use with Reduced Hospitalization, Intensive Care Unit Admission, and Mortality in Patients with Mild to Moderate COVID-19

BACKGROUND

Clinical data to support the use of bamlanivimab for the treatment of outpatients with mild to moderate coronavirus disease-19 (COVID-19) is needed.

METHODS

2,335 patients who received single-dose bamlanivimab infusion between November 12, 2020 to February 17, 2021 were compared with a propensity-matched control of 2,335 untreated patients with mild to moderate COVID-19 at Mayo Clinic facilities across 4 states. The primary outcome was the rate of hospitalization at days 14, 21 and 28.

RESULTS

The median age of the population was 63; 47.3% of the bamlanivimab-treated cohort were ≥65 years; 49.3% were female. High-risk characteristics included hypertension (54.2%), body mass index ≥35 (32.4%), diabetes mellitus (26.5%), chronic lung disease (25.1%), malignancy (16.6%), and renal disease (14.5%). Patients who received bamlanivimab had lower all-cause hospitalization rates at days 14 (1.5% vs 3.5%; Odds Ratio [OR], 0.38), 21 (1.9% vs 3.9%; OR, 0.46), and 28 (2.5% vs 3.9%; OR, 0.61). Secondary exploratory outcomes included lower intensive care unit admission rates at days 14 (0.14% vs 1%; OR, 0.12), 21 (0.25% vs 1%; OR: 0.24) and 28 (0.56% vs 1.1%; OR: 0.52), and lower all-cause mortality at days 14 (0% vs 0.33%), 21 (0.05% vs 0.4%; OR,0.08) and 28 (0.11% vs 0.44%; OR, 0.01). Adverse events were uncommon with bamlanivimab, occurring in 19/2355, most commonly fever (n=6), nausea (n=5), and lightheadedness (n=3).

CONCLUSIONS

Among high-risk patients with mild to moderate COVID-19, treatment with bamlanivimab was associated with a statistically significant lower rate of hospitalization compared with usual care.

FUNDING

Mayo Clinic.

A Framework for Outpatient Infusion of Antispike Monoclonal Antibodies to High-Risk Patients with Mild-to-Moderate Coronavirus Disease-19: The Mayo Clinic Model

The administration of spike monoclonal antibody treatment to patients with mild to moderate COVID-19 is very challenging. This article summarizes essential components and processes in establishing an effective spike monoclonal antibody infusion program. Rapid identification of a dedicated physical infrastructure was essential to circumvent the logistical challenges of caring for infectious patients while maintaining compliance with regulations and ensuring the safety of our personnel and other patients. Our partnerships and collaborations among multiple different specialties and disciplines enabled contributions from personnel with specific expertise in medicine, nursing, pharmacy, infection prevention and control, electronic health record (EHR) informatics, compliance, legal, medical ethics, engineering, administration, and other critical areas. Clear communication and a culture in which all roles are welcomed at the planning and operational tables are critical to the rapid development and refinement needed to adapt and thrive in providing this time-sensitive beneficial therapy. Our partnerships with leaders and providers outside our institutions, including those who care for underserved populations, have promoted equity in the access of monoclonal antibodies in our regions. Strong support from institutional leadership facilitated expedited action when needed, from a physical, personnel, and system infrastructure standpoint. Our ongoing real-time assessment and monitoring of our clinical program allowed us to improve and optimize our processes to ensure that the needs of our patients with COVID-19 in the outpatient setting are met.

A mobile unit overcomes the challenges to monoclonal antibody infusion for COVID-19 in skilled care facilities

Background

Residents of nursing homes and long‐term care facilities are at increased risk for severe coronavirus disease‐19 (COVID‐19) but may not be able to access monoclonal antibody therapies offered at outpatient infusion centers due to frailty and logistical issues. We describe a mobile monoclonal antibody infusion program for patients with COVID‐19 in skilled nursing facilities and provide descriptive data on its outcomes.

Design

Retrospective cohort study.

Setting

Collaboration between Mayo Clinic and skilled nursing facilities in Southeast Minnesota was developed to administer anti‐spike monoclonal antibodies under the FDA Emergency Use Authorization.

Participants

Seventy five residents of skilled nursing facilities at high risk of COVID‐19 complications.

Exposure

Emergency use treatment with bamlanivimab and casirivimab–imdevimab.

Measurements

Hospitalization and medically attended visits.

Results

The mobile infusion unit, staffed by Mayo Clinic Infusion Therapy registered nurses and supported by the skilled nursing facility staff, infused anti‐spike monoclonal antibodies to 45 of 75 patients (average age, 77.8 years) in December 2020. The infusions occurred at an average of 4.3 days after COVID‐19 diagnosis. Fourteen days after infusion, there were no deaths, two emergency department visits, and three hospitalizations, for a combined event rate of 11.1%. There was one reported adverse event.

Conclusion

The implementation of a mobile infusion unit embedded in a collaborative process resulted in rapid infusion of monoclonal antibodies to high‐risk COVID‐19 patients in skilled nursing facilities, who would otherwise be unable to access the novel therapies. The therapies were well tolerated and appear beneficial. Further study is warranted to explore the scalability and efficacy of this program.

New animal model for the study of postmenopausal coronary and cerebral artery function: the Watanabe heritable hyperlipidemic rabbit fed on a diet avoiding phytoestrogens

OBJECTIVE

To evaluate the effect of estrogen replacement therapy (ERT) on the functional characteristics of coronary and cerebral arteries in a new rabbit model for postmenopausal vascular function.

METHODS

Female ovariectomized Watanabe heritable hyperlipidemic (WHHL) rabbits were randomized to treatment for 16 weeks with either 17 beta-estradiol or placebo. The chow used was semi-synthetic, thereby avoiding the influence of phytoestrogens. Ring segments of cerebral and coronary arteries were mounted for isometric tension recordings in myographs. The passive and active length-tension relationships for electromechanical (high potassium), pharmacomechanical (histamine) and combined electro- and pharmacomechanical (high potassium plus histamine) contraction were evaluated.

RESULTS

Treatment with 17 beta-estradiol significantly changed the active length-tension relationship for the electromechanical response in the proximal coronary arteries. No changes were observed for the passive length-tension relationships.

CONCLUSIONS

Long-term treatment with 17 beta-estradiol lowered the electromechanical tonus of atherosclerotic coronary arteries proximally, where the atherosclerosis is most developed. This could be one of the mechanisms behind the putative protective effect of hormone replacement therapy against ischemic heart disease. The study presents a promising new animal model for the investigation of postmenopausal coronary and cerebral artery function. The data correspond well with epidemiological observations in postmenopausal women.

In utero reproductive study in rats exposed to nonylphenol

Alkylphenol ethoxylates are widely used non-ionic surfactants. Nonylphenol ethoxylate constitutes 82% of the production of all alkylphenol ethoxylates and the breakdown product of nonylphenol ethoxylate, nonylphenol (NP) has been shown to be estrogenic in both in vitro and in vivo screening assays. To determine the potential reproductive toxicity of NP, a one-generation in utero study was conducted. Rats were dosed from gestation day 11 through 18 with NP at 3, 15, or 75 mg/kg/day or diethylstilbestrol (DES) at 30 microg/kg/day. DES was used as a positive control. Both substances were given orally by gavage. Male offspring were sacrificed at postnatal day (PND) 11, 21, or 110 and reproductive parameters were evaluated. Pup birth weight and body weight and percent motile sperm at age of 110 day were significantly reduced by DES. The absolute weight of the right epididymis was significantly reduced in the DES group. The absolute weight of the right epididymis were also significantly decreased in the animals exposed to 75 or 15 mg/kg/day NP, effects which disappeared when organ weight was related to body weight. This study showed a dose-dependent effect of nonylphenol on male reproductive development at doses of 75 and 15 mg/kg bw/day based on absolute epididymal weight.

Quantification of antiandrogen effect determined by Lightcycler technology

During the last decade, the possible effects of xenobiotics on male reproductive health have resulted in great concern. More recently, evidence of antiandrogen effect in vivo by certain chemicals has been reported. The classical Hershberger in vivo assay determining organ weight changes can be improved by measuring hormone levels as well as determining changes in gene expression of androgen-responsive genes. A real-time RT-PCR method using LightCycler technology (Roche) suitable for quantitative determination of gene expression is described. The technique combines rapid thermocycling with online fluorescence detection of PCR product formation. In this study, investigation of expression of prostate specific binding protein polypeptide C3 (PBP C3) and testosterone-repressed prostatic message 2 (TRPM-2) in the ventral prostate was performed in 60-days-old castrated Wistar rats treated daily with testosterone with or without addition of flutamide or vinclozolin for 7 days in total. We show that we can quantify the level of gene expression by use of LightCycler technology, supported by changes in reproductive organ weights as well as in hormone levels, and that analysis of gene expression levels is an even more sensitive endpoint.

17beta-Estradiol but not the phytoestrogen naringenin attenuates aortic cholesterol accumulation in WHHL rabbits

The effects of 17beta-estradiol (17beta-E(2)) or the phytoestrogen naringenin on spontaneous atherosclerosis were studied in 36 ovariectomized homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits receiving a semisynthetic control diet; this diet added 0.0040% 17beta-E(2;) or 0.20% naringenin, for 16 weeks. The uterine weight was increased (P < 0.001) and the concentration of estrogen receptor alpha was decreased (P < 0.001) in the 17beta-E(2) group compared with the controls. Total plasma cholesterol and triglycerides were not different from those in the controls. In lipoproteins, HDL cholesterol was increased (P < 0.01), and LDL triglyceride and IDL triglyceride were lowered (P < 0.05). The oxidation (as concentration of malondialdehyde) was increased in LDL (P < 0.05) but not in plasma. The cholesterol accumulation was decreased (P < 0.05) in the ascending aorta and in the total aorta but the ratio of intima to media and area of intima in ascending, thoracic, and abdominal aorta were not significantly different. In the naringenin group the only differences, compared with the control group, were increased HDL cholesterol (P < 0.001) and decreased activity of glutathione reductase (P < 0.05). In conclusion, 17beta-E(2), but not naringenin, attenuated aortic cholesterol accumulation independently of plasma and LDL cholesterol. Further, these results support previously suggested pro-oxidant ability of 17beta-E(2) toward LDL and a possible connection between the pro-oxidant nature of 17beta-E(2) and its antiatherogenic effect.

Towards disentangling coupled electronic-vibrational dynamics in ultrafast non-adiabatic processes

Femtosecond time-resolved photoelectron spectroscopy is emerging as a new technique for investigating polyatomic excited state dynamics. Due to the sensitivity of photoelectron spectroscopy to both electronic configurations and vibrational dynamics, it is well suited to the study of non-adiabatic processes such as internal conversion, which often occur on sub-picosecond time scales. We discuss the technical requirements for such experiments, including lasers systems, energy- and angle-resolved photoelectron spectrometers and new detectors for coincidence experiments. We present a few examples of these methods applied to problems in diatomic wavepacket dynamics and ultrafast non-adiabatic processes in polyatomic molecules.

Three dimensional alignment of molecules using elliptically polarized laser fields

We demonstrate, theoretically and experimentally, that an intense, elliptically polarized, nonresonant laser field can simultaneously force all three axes of a molecule to align along given axes fixed in space, thus inhibiting the free rotation in all three Euler angles. Theoretically, the effect is illustrated through time dependent quantum mechanical calculations. Experimentally, 3, 4-dibromothiophene molecules are aligned with a nanosecond laser pulse. The alignment is probed by 2D ion imaging of the fragments from a 20 fs laser pulse induced Coulomb explosion.

Effect of training on insulin sensitivity of glucose uptake and lipolysis in human adipose tissue

Training increases insulin sensitivity of both whole body and muscle in humans. To investigate whether training also increases insulin sensitivity of adipose tissue, we performed a three-step hyperinsulinemic, euglycemic clamp in eight endurance-trained (T) and eight sedentary (S) young men [insulin infusion rates: 10,000 (step I), 20,000 (step II), and 150,000 (step III) microU x min(-1) x m(-2)]. Glucose and glycerol concentrations were measured in arterial blood and also by microdialysis in interstitial fluid in periumbilical, subcutaneous adipose tissue and in quadriceps femoris muscle (glucose only). Adipose tissue blood flow was measured by (133)Xe washout. In the basal state, adipose tissue blood flow tended to be higher in T compared with S subjects, and in both groups blood flow was constant during the clamp. The change from basal in arterial-interstitial glucose concentration difference was increased in T during the clamp but not in S subjects in both adipose tissue and muscle [adipose tissue: step I (n = 8), 0.48 +/- 0.18 mM (T), 0.23 +/- 0.11 mM (S); step II (n = 8), 0.19 +/- 0.09 (T), -0.09 +/- 0.24 (S); step III (n = 5), 0.47 +/- 0.24 (T), 0.06 +/- 0.28 (S); (T: P < 0.001, S: P > 0.05); muscle: step I (n = 4), 1. 40 +/- 0.46 (T), 0.31 +/- 0.21 (S); step II (n = 4), 1.14 +/- 0.54 (T), -0.08 +/- 0.14 (S); step III (n = 4), 1.23 +/- 0.34 (T), 0.24 +/- 0.09 (S); (T: P < 0.01, S: P > 0.05)]. Interstitial glycerol concentration decreased faster in T than in S subjects [half-time: T, 44 +/- 9 min (n = 7); S, 102 +/- 23 min (n = 5); P < 0.05]. In conclusion, training enhances insulin sensitivity of glucose uptake in subcutaneous adipose tissue and in skeletal muscle. Furthermore, interstitial glycerol data suggest that training also increases insulin sensitivity of lipolysis in subcutaneous adipose tissue. Insulin per se does not influence subcutaneous adipose tissue blood flow.

Lack of oestrogenic effects of food preservatives (parabens) in uterotrophic assays

The oestrogenic activity of the parabens, methyl-, ethyl- and propyl p-hydroxybenzoate, widely used as antimicrobials in food, and butyl p-hydroxybenzoate, which is used in cosmetic products, and their shared main metabolite p-hydroxybenzoic acid was investigated in a mouse uterotrophic assay. Immature B6D2F1 mice were treated with oral or subcutaneous doses of the test compounds for three consecutive days. p-Hydroxybenzoic acid and butyl p-hydroxybenzoate were also tested by the subcutaneous route in a rat uterotrophic assay. A significant increase in the uterus weight at day 4 was considered an oestrogenic effect. In the mouse assay, none of the compounds tested produced any oestrogenic response at dose levels up to 100mg/kg body weight per day, for ethyl p-hydroxybenzoate even at a dose level of 1000mg/kg body weight per day. In immature Wistar rats, subcutaneous administration of butyl p-hydroxybenzoate produced a weak oestrogenic response at 600mg/kg body weight per day.

Glucose clearance in aged trained skeletal muscle during maximal insulin with superimposed exercise

Insulin and muscle contractions are major stimuli for glucose uptake in skeletal muscle and have in young healthy people been shown to be additive. We studied the effect of superimposed exercise during a maximal insulin stimulus on glucose uptake and clearance in trained (T) (1-legged bicycle training, 30 min/day, 6 days/wk for 10 wk at approximately 70% of maximal O(2) uptake) and untrained (UT) legs of healthy men (H) [n = 6, age 60 +/- 2 (SE) yr] and patients with Type 2 diabetes mellitus (DM) (n = 4, age 56 +/- 3 yr) during a hyperinsulinemic ( approximately 16,000 pmol/l), isoglycemic clamp with a final 30 min of superimposed two-legged exercise at 70% of individual maximal heart rate. With superimposed exercise, leg glucose extraction decreased (P < 0.05), and leg blood flow and leg glucose clearance increased (P < 0.05), compared with hyperinsulinemia alone. During exercise, leg blood flow was similar in both groups of subjects and between T and UT legs, whereas glucose extraction was always higher (P < 0.05) in T compared with UT legs (15.8 +/- 1.2 vs. 14.6 +/- 1.8 and 11.9 +/- 0.8 vs. 8.8 +/- 1.8% for H and DM, respectively) and leg glucose clearance was higher in T (H: 73 +/- 8, DM: 70 +/- 10 ml. min(-1). kg leg(-1)) compared with UT (H: 63 +/- 8, DM: 45 +/- 7 ml. min(-1). kg leg(-1)) but not different between groups (P > 0.05). From these results it can be concluded that, in both diabetic and healthy aged muscle, exercise adds to a maximally insulin-stimulated glucose clearance and that glucose extraction and clearance are both enhanced by training.

Discovery of a series of cyclohexylethylamine-containing protein farnesyltransferase inhibitors exhibiting potent cellular activity

Synthesis of a library of secondary benzylic amines based on the Sebti-Hamilton type peptidomimetic farnesyltransferase (FTase) inhibitor FTI-276 (1) led to the identification of 6 as a potent enzyme inhibitor (IC(50) of 8 nM) which lacked the problematic thiol residue which had been a common theme in many of the more important FTase inhibitors reported to date. It has previously been disclosed that addition of o-tolyl substitution to FTase inhibitors of the general description 2 had a salutary effect on both FTase inhibition and inhibition of Ras prenylation in whole cells. Combination of these two observations led us to synthesize 7, a potent FTase inhibitor which displayed an IC(50) of 0.16 nM for in vitro inhibition of FTase and an EC(50) of 190 nM for inhibition of whole cell Ras prenylation. Modification of 7 by classical medicinal chemistry led to the discovery of a series of potent FTase inhibitors, culminating in the identification of 25 which exhibited an IC(50) of 0.20 nM and an EC(50) of 4.4 nM. In vivo tests in a nude mouse xenograft model of human pancreatic cancer (MiaPaCa cells) showed that oral dosing of 25 gave rise to impressive attenuation of the growth of this aggressive tumor cell line.

The effect of intense exercise on postprandial glucose homeostasis in type II diabetic patients

AIMS/HYPOTHESIS

The influence of postprandial high intensity exercise on glycaemia was studied in patients with Type II diabetes mellitus.

METHODS

Patients who were treated by diet only (n = 8) ate a standardised breakfast and 4 h later a standardised lunch. They were studied in the resting state (control day) and on another day (exercise day) when they did intermittent exercised at high intensity after breakfast) (4 bouts including 3 min at 56.5 +/- 3.9 % V.(O2) (max) (means +/- SEM), 4 min at 98.3 +/- 5.1 % V.(O2) (max) and 6 min of rest). Responses were calculated as areas under the plasma concentration curve (AUC) during 4 h after either breakfast or lunch.

RESULTS

Breakfast-AUCs for glucose, insulin and C peptide were lower (p < 0.05) on the exercise day compared with the control day (glucose: 538 +/- 94 vs 733 +/- 64 mmol. l(-1). 240 min; insulin: 16 +/- 4 vs 22 +/- 3 pmol. ml(-1). 240 min; C peptide: 143 +/- 22 vs 203 +/- 29 pmol. ml(-1). 240 min). After breakfast glucose appearance was unaffected by exercise, whereas disappearance and clearance increased (p < 0.05). Muscle glycogen was diminished by exercise (p < 0.05). After lunch no differences were observed between experiments. Exercise-induced reductions in glucose, insulin and C peptide responses were similar (p > 0.05) in this study of intermittent, high intensity exercise and in a previous study of isocaloric but prolonged moderate (45 min at 53 +/- 2 % V.(O2) (max)) postprandial exercise.

CONCLUSION/INTERPRETATION

Postprandial high intensity exercise does not deteriorate glucose homeostasis but reduces both glucose concentrations and insulin secretion. The effect of exercise is related to energy expenditure rather than to peak exercise intensity. Finally, postprandial exercise does not influence glucose homeostasis during a subsequent main meal. [Diabetologia (1999) 42: 1282-1292]

Interaction of sulfonylureas and exercise on glucose homeostasis in type 2 diabetic patients

OBJECTIVE

To determine whether the plasma glucose-lowering effects of sulfonylureas and acute submaximal exercise are additive and, accordingly, to determine whether they may increase the risk of hypoglycemia when combined in fasting patients.

RESEARCH DESIGN AND METHODS

Eight postabsorptive type 2 diabetic patients were examined at three occasions: after oral sulfonylurea (7 mg glibenclamide), during 60 min of ergometer cycle exercise at 57 +/- 3% of VO2max, and during exercise after glibenclamide.

RESULTS

Heart rate, VO2, and lactate responses to exercise were comparable (P > 0.05) on days with and without glibenclamide. Plasma insulin concentrations were always increased by glibenclamide, and they were lowered identically by exercise with and without glibenclamide. However, throughout exercise, absolute concentrations of insulin were lower on days without glibenclamide compared with days with glibenclamide (34.5 +/- 4.7 vs. 47.4 +/- 5.5 pmol/l; P < 0.05). At the start of exercise, glucose concentrations were similar between experiments (P > 0.05). The rate of decrease in glucose during exercise was higher (P < 0.05) on days with both glibenclamide and exercise, compared with days with glibenclamide alone and days with exercise alone (-0.035 +/- 0.009 vs. -0.016 +/- 0.002 and -0.022 +/- 0.005 mmol.l-1.min-1, respectively). Consequently, the glucose nadir was lower on days with glibenclamide and exercise than on days with glibenclamide or exercise alone (6.7 +/- 1.1 vs. 8.1 +/- 0.9 and 7.6 +/- 1.0 mmol/l, respectively; P < 0.05). During exercise, the rate of appearance of plasma glucose determined by 3-[3H]glucose infusion was lower on days with glibenclamide than on days without glibenclamide (2.3 +/- 0.1 vs. 2.9 +/- 0.1 mg.min-1.kg-1; P < 0.05). In contrast, glucose clearance was identical (P > 0.05).

CONCLUSIONS

In postabsorptive type 2 diabetic patients, the hypoglycemic action of glibenclamide and exercise is enhanced when the treatments are combined. The interaction reflects an increased inhibition by glibenclamide-enhanced insulin levels of hepatic glucose production when hepatic glucose production is accelerated by exercise.

Effect of a new starch-free bread on metabolic control in NIDDM patients

BACKGROUND AND AIM

The aim of the study was to evaluate the effect on blood glucose levels in non-insulin-dependent diabetics (NIDDM) of reduction of the carbohydrate content through the use of a new, almost starch-free type of bread (SF-bread). We only substituted the bread in the breakfast meal.

METHODS AND RESULTS

The study consisted of two parts: 1) a two-day randomized study of the effect of SF-bread on the morning blood glucose levels of NIDDM patients and 2) an open, crossover trial of three months duration where each patient was given SF- or ordinary bread. Ten patients participated in the first part and eight in the second part of the study. All patients had well established non insulin-dependent diabetes mellitus. In the first part of the study, the area under the curve describing time-dependent changes in blood glucose level after a standard breakfast was significantly lower in patients on SF-bread (182 +/- 154 Units; mean value +/- SD) than in the controls (630 +/- 258 Units; p < 0.00001). Peak blood glucose concentration was 14.8 +/- 2.3 mM on the control day and 11.6 +/- 1.7 mM on the SF-bread day (p < 0.001). In the second part of the study, the diet including SF-bread reduced fasting blood glucose from 13.3 +/- 3.5 mM to 10.2 +/- 2.0 mM (p < 0.006) and the fraction of HbA1c from 0.090 +/- 0.014 to 0.081 +/- 0.015 (p < 0.02). Similar changes were not seen on the ordinary diet. Serum cholesterol levels were significantly reduced by the SF-bread as compared to the ordinary diet (5.8 +/- 0.6 to 5.5 +/- 0.5 mM versus 5.7 +/- 0.8 to 5.8 +/- 0.7 mM; p < 0.05).

CONCLUSIONS

Substitution of ordinary bread with starch-free bread at breakfast causes significant improvements in blood glucose levels in NIDDM patients on both a short and long term basis. Possibly secondary to this, a favorable influence on lipid levels was noted.

The IPCS Collaborative Study on Neurobehavioral Screening Methods: IV. Control data. Steering Group

The goal of the International Programme on Chemical Safety (IPCS) Collaborative Study on Neurobehavioral Screening Methods was to determine the intra- and inter-laboratory reliability of a functional observational battery (FOB) and an automated assessment of motor activity in eight laboratories worldwide. The control data were crucial to the outcome of the studies in terms of sensitivity and reliability of the test measures, which in turn impact on the between-laboratory comparisons of chemical effects. In addition, analyses of control data can aid in determining endpoints that may require modification to improve their sensitivity and reliability. The control data from the eight laboratories were examined in terms of the following parameters: 1) control variability within studies for each laboratory; 2) within-laboratory replicability of control values across studies; 3) within-laboratory stability of control values over the course of testing for a given study; and 4) between-laboratory comparisons of parameters (1), (2), and (3). The analyses indicated considerable differences across endpoints, wherein some measures showed high variability and little replicability, while others were extremely reproducible. Generally, there were similar ranges of variability and replicability of control data across laboratories, although in some cases one or two laboratories were markedly different from the others. The physiological (weight, body temperature) and neuromuscular (grip strength, landing foot splay) endpoints exhibited the least variability, whereas the subjective assessments of reactivity varied the most. These data indicate a reasonable degree of comparability in the data generated in the participating laboratories.

The IPCS Collaborative Study on Neurobehavioral Screening Methods: V. Results of chemical testing. Steering Group

The IPCS Collaborative Study on Neurobehavioral Screening Methods was undertaken to determine the intra- and inter-laboratory reliability of a functional observational battery (FOB) and an automated assessment of motor activity in eight laboratories world-wide. Following the training phase and the conduct of proficiency studies in all laboratories, participants proceeded to test the effects of seven chemicals in both single dose and four-week repeated dosing scenarios. The chemicals studied were acrylamide, bisacrylamide, p,p'-DDT, lead acetate, parathion, toluene, and triethyl tin. Participants received coded samples from a common source. In order to judge the general utility of these procedures in a diversity of testing situations, laboratories conducted the studies under their standard conditions, using their choice of rat strain and test equipment. Chemical does and time of peak effect for acute testing were determined by each laboratory: these parameters were quite similar for some chemicals, but varied greatly for others. The results of the chemical tests indicated that while there was some variability in the data on specific endpoints, all laboratories detected and characterized the effects of all but one of the known neurotoxicants. The one exception (toluene) was probably due to other factors (e.g., dose level, route of administration) rather than lack of sensitivity of the test methods. This study provides extensive data regarding the use of neurobehavioral screening methods over a range of laboratory conditions as well as the reliability, sensitivity, and robustness of the tests to detect neurotoxic potential of chemicals.

The IPCS Collaborative Study on Neurobehavioral Screening Methods: III. Results of proficiency studies. Steering Group

The goal of the IPCS Collaborative Study on Neurobehavioral Screening Methods was to determine the intra- and inter-laboratory reliability of a functional observational battery (FOB) and an automated assessment of motor activity in eight laboratories world-wide. The first phase of the Collaborative Study involved training the participants: evidence of training was then evaluated using positive-control compounds. The positive-control studies required the laboratories to identify, using the FOB, specific neurotoxic syndromes produced by acute exposure to p,p'-DDT, parathion, and by short-term repeated dosing with acrylamide. For the sake of expediency, only one dose of each chemical was used instead of collecting dose-response data. Motor activity test chambers were not of uniform design. The laboratories were therefore required to demonstrate adequate sensitivity by the ability to detect statistically-significant activity increases and decreases produced by triadimefon and chlorpromazine, respectively, following acute administration of a range of doses. The resulting FOB and motor activity data showed variability in the magnitude of effects obtained: some of these differences were attributed to miscommunications, difficulties with the techniques or protocol, or the limitations of having only one dose. All laboratories, however, successfully met the criteria set forth by the Study Steering Committee.

The effect of altitude hypoxia on glucose homeostasis in men

1. Exposure to altitude hypoxia elicits changes in glucose homeostasis with increases in glucose and insulin concentrations within the first few days at altitude. Both increased and unchanged hepatic glucose production (HGP) have previously been reported in response to acute altitude hypoxia. Insulin action on glucose uptake has never been investigated during altitude hypoxia. 2. In eight healthy, sea level resident men (27 +/- 1 years (mean +/- S.E.M); weight, 72 +/- 2 kg; height, 182 +/- 2 cm) hyperinsulinaemic (50 mU min-1 m-2), euglycaemic clamps were carried out at sea level, and subsequently on days 2 and 7 after a rapid passive ascent to an altitude of 4559 m. 3. Acute mountain sickness scores increased in the first days of altitude exposure, with a peak on day 2. Basal HGP did not change with the transition from sea level (2.2 +/- 0.2 mg min-1 kg-1) to altitude (2.0 +/- 0.1 and 2.1 +/- 0.2 mg min-1 kg-1, days 2 and 7, respectively). Insulin-stimulated glucose uptake rate was halved on day two compared with sea level (4.5 +/- 0.6 and 9.8 +/- 1.1 mg min-1 kg-1, respectively; P < 0.05), and was partly restored on day 7 (7.4 +/- 1.4 mg min-1 kg-1; P < 0.05 vs. day two and sea level). Concentrations of glucagon and growth hormone remained unchanged, whereas glucose, C-peptide and cortisol increased on day 2. Noradrenaline concentrations increased during the stay at altitude, while adrenaline concentrations remained unchanged. In response to insulin infusion, catecholamines increased on day 2 (noradrenaline and adrenaline) and day 7 (adrenaline), but not at sea level. 4. In conclusion, insulin action decreases markedly in response to two days of altitude hypoxia, but improves with more prolonged exposure. HGP is always unchanged. The changes in insulin action may in part be explained by the changes in counter-regulatory hormones.

The effect of moderate exercise on postprandial glucose homeostasis in NIDDM patients

The influence of exercise on glycaemia in the post-prandial state was studied for the first time in non-insulin-dependent diabetic (NIDDM) patients. Meal-induced glucose responses were followed for 8 h in 9 diet-treated patients with NIDDM. Subjects consumed a standardized breakfast and 4 h later a standardized lunch. They were studied in the resting state (control day (CD)) and on another day 45 min of bicycle exercise (53 +/- 2% VO2max (mean +/- SEM)) was performed 45 min after breakfast (exercise day (ED)). On day 3 (diet day (DD)), the breakfast meal was reduced corresponding to the extra energy expenditure during the exercise period on ED. Responses were calculated as areas under the plasma concentration curve (AUC) during 4 h after either breakfast (B-AUC) or lunch (L-AUC). B-AUC for glucose was identical on ED (215 +/- 63 mmol/l.240 min) and DD (219 +/- 60 mmol/l.240 min) and on these days lower (p < 0.05) than on CD (453 +/- 78 mmol/l.240 min). L-AUC for glucose on CD, ED and DD did not differ significantly. B-AUCs for both insulin and C-peptide were also significantly lower on ED and DD as compared to CD (Insulin: 31337 +/- 8682, 26092 +/- 6457 and 47649 +/- 15046 mmol/l.240 min, respectively. C-peptide: 99 +/- 19, 104 +/- 26 and 195 +/- 31 pmol/ml.240 min, respectively). Rate of appearance (Ra) for glucose was unaffected by exercise whereas rate of disappearance (Rd) increased significantly. No differences in Ra or Rd were observed after lunch. In conclusion, post-prandial exercise of moderate intensity decreases glycaemia and plasma insulin levels after breakfast in NIDDM patients, but this effect does not persist during and after the following lunch meal. Reduction of breakfast caloric intake has the same effect on post-prandial glycaemia and insulin secretion as an equivalent exercise-induced increase in caloric expenditure.

Training-induced enhancement of insulin action in human skeletal muscle: the influence of aging

Age-induced reduction of whole body insulin action has been attributed to decreased insulin action in skeletal muscle. Physical training improves insulin action, but the effect has never been investigated specifically in aged human skeletal muscle. Seven young men [age: 23 +/- 1 yr (mean +/- SE; range, 21-24 yr); weight: 70 +/- 1 kg; body fat: 8 +/- 1%] and eight aged men [59 +/- 1 yr (range, 58-64 yr); 83 +/- 2 kg; 20 +/- 2%] performed one-legged bicycle training on a modified ergometer cycle for 10 weeks, 6 days/week, at 70% of VO2 peak. Glucose clearance rates in whole body and leg were measured 16 hr after training by a hyperinsulinemic (28, 88, and 480 mU.min-1.min-2), isoglycemic clamp combined with leg balance technique. Peak oxygen uptake during the bicycle test was always lower (p < .05) in aged vs. young subjects. Furthermore, VO2 peak was higher after training in trained (T) vs. untrained (UT) (p < .05) legs. Whole body glucose clearance rate was lower in aged vs. young subjects (p < .05) when expressed per kg body weight, but similar when expressed relative to fat free mass. Leg blood flow was always lower in aged vs. young men (p < .05). At basal and during insulin infusion, leg blood flow in young men did not differ significantly in T vs. UT legs (maximum insulin: 81 +/- 7 vs. 71 +/- 5 ml.min-1.kg leg-1), while in aged subjects it increased (p < .05) with training (maximum insulin: 57 +/- 5 vs. 48 +/- 5 ml.min-1.kg leg-1). Leg glucose extraction was always higher in aged vs. young men during the two last clamp steps (p < .05). Furthermore, leg glucose extraction was increased by training in young (p < .05) but not significantly in aged subjects. Leg glucose clearance rates increased (p < .05) with training and was similar in aged men (T: 1 +/- 1, 8 +/- 1, 21 +/- 2, and 24 +/- 2; UT: 1 +/- 1, 6 +/- 1, 14 +/- 2, and 20 +/- 2 ml.min-1.kg leg-1) and young men (T: 1 +/- 1, 12 +/- 3, 23 +/- 3, and 26 +/- 3; UT: 1 +/- 1, 8 +/- 2, 17 +/- 2, and 21 +/- 2 ml.min-1.kg leg-1). Therefore, insulin action in muscle is not reduced by aging. At high insulin concentrations, the leg blood flow is lower, whereas glucose extraction is higher in aged compared with young men. Training increases overall insulin action on glucose clearance in skeletal muscle identically in aged and young subjects.

Insulin-stimulated muscle glucose clearance in patients with NIDDM. Effects of one-legged physical training

Physical training increases insulin action in skeletal muscle in healthy men. In non-insulin-dependent diabetes mellitus (NIDDM), only minor improvements in whole-body insulin action are seen. We studied the effect of training on insulin-mediated glucose clearance rates (GCRs) in the whole body and in leg muscle in seven patients with NIDDM and in eight healthy control subjects. One-legged training was performed for 10 weeks. GCR in whole body and in both legs were measured before, the day after, and 6 days after training by hyperinsulinemic (28, 88, and 480 mU x min(-1) x m(-2)), isoglycemic clamps combined with the leg balance technique. On the 5th day of detraining, one bout of exercise was performed with the nontraining leg. Muscle biopsies were obtained before and after training. Whole-body GCRs were always lower (P < 0.05) in NIDDM patients compared with control subjects and increased (P < 0.05) in response to training. In untrained muscle, GCR was lower (P < 0.05) in NIDDM patients (13 +/- 4, 91 +/- 9, and 148 +/- 12 ml/min) compared with control subjects (56 +/- 12, 126 +/- 14, and 180 +/- 14 ml/min). It Increased (P < 0.05) in both groups in response to training (43 +/- 10, 144 +/- 17, and 205 +/- 24 [NIDDM patients] and 84 +/- 10, 212 +/- 20, and 249 +/- 16 ml/min [control subjects]). Acute exercise did not increase leg GCR. In NIDDM patients, the effect of training was lost after 6 days, while the effect lasted longer in control subjects. Training increased (P < 0.05) muscle lactate production and glucose storage as well as glycogen synthase (GS) mRNA in both groups. We conclude that training increases insulin action in skeletal muscle in control subjects and NIDDM patients, and in NIDDM patients normal values may be obtained. The increase in trained muscle cannot fully account for the increase in whole-body GCR. Improvements in GCR involve enhancement of insulin-mediated increase in muscle blood flow and the ability to extract glucose. They are accompanied by enhanced nonoxidative glucose disposal and increases in GS mRNA. The improvements in insulin action are short-lived.

Normal effect of insulin to stimulate leg blood flow in NIDDM

In patients with non-insulin-dependent diabetes mellitus (NIDDM), a decreased effect of insulin in stimulating leg blood flow (LBF) has been reported. We reinvestigated the effect of insulin on LBF and validated our data by use of other measures. Eight healthy men (control group) and seven men with NIDDM were studied (age 59 +/- 1 and 58 +/- 3 years, weight 83 +/- 3 and 86 +/- 6 kg, fat-free mass 66 +/- 1 and 64 +/- 3 kg, respectively [mean +/- SE, all P > 0.05]; body mass index 26 +/- 1 and 29 +/- 1 kg/m2, fasting plasma insulin 72 +/- 7 and 187 +/- 22 pmol/l, fasting plasma glucose 5.8 +/- 0.2 and 10.2 +/- 1.7 mmol/l [all P < 0.05]). A three-step hyperinsulinemic glucose clamp (ambient glucose level) was performed, combined with catheterization of an artery and both femoral veins. Expiratory air was collected, LBF was measured by thermodilution, and blood was sampled and analyzed for oxygen content. Insulin concentration was increased to 416 +/- 22 and 509 +/- 43 (step I), 1,170 +/- 79 and 1,299 +/- 122 (step II), and 15,936 +/- 1,126 and 16,524 +/- 1,916 (step III) pmol/l in control and NIDDM subjects, respectively (P > 0.05). LBF increased similarly (P > 0.05) in the two groups (from 287 +/- 23 and 302 +/- 12 [basal] to 308 +/- 31 and 362 +/- 9 [I], 371 +/- 29 and 409 +/- 17 [II], and 434 +/- 32 and 472 +/- 29 [III] ml.min-1.leg-1 in control and NIDDM subjects, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Physical training increases muscle GLUT4 protein and mRNA in patients with NIDDM

Patients with non-insulin-dependent diabetes mellitus (NIDDM) exhibit insulin resistance and decreased glucose transport in skeletal muscle. Total content of muscle GLUT4 protein is not affected by NIDDM, whereas GLUT4 mRNA content is reported, variously, to be unaffected or increased. Physical training is recommended in the treatment of NIDDM, but the effect of training on muscle GLUT4 protein and mRNA content is unknown. To clarify the effect of training in NIDDM, seven men with NIDDM (58 +/- 2 years of age [mean +/- SE]) and eight healthy men (59 +/- 1 years of age) (control group) performed one-legged ergometer bicycle training for 9 weeks, 6 days/week, 30 min/day. Biopsies were obtained from the vastus lateralis leg muscle before and after training. GLUT4 protein analyses was performed along with analyses of muscle biopsies from five young (23 +/- 1 years of age) (young group), healthy subjects who participated in a previously published identical study. In response to training, maximal oxygen uptake increased (delta 3.3 +/- 1.8 in NIDDM subjects and 4.5 +/- 1.2 ml.min-1.kg-1 in control subjects [both P < 0.05]). Before training, GLUT4 protein content was similar in NIDDM, control, and young subjects (0.35 +/- 0.02, 0.34 +/- 0.03, and 0.41 +/- 0.03 arbitrary units, respectively), and it increased (P < 0.05) in all groups during training (to 0.43 +/- 0.03, 0.40 +/- 0.03, and 0.57 +/- 0.08 arbitrary units, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetone potentiation and influence on the reversibility of 2,5-hexanedione-induced neurotoxicity studied with behavioural and morphometric methods in rats

The neurobehavioural and morphologic changes and the reversibility in 2,5-hexanedione-induced polyneuropathy in rats were studied. The potentiation and influence of acetone on the reversibility of the induced neurotoxicity was also evaluated. Male rats were treated for 6 weeks with 0.5% w/v 2,5-hexanedione alone or in combination with 0.50% w/v acetone in the drinking water. During the treatment period, neurobehavioural tests (ambulation and rearing in open field, balance on the accelerating rotarod and fore-and hindlimb muscle strength measurements) were performed weekly. After 6 weeks half of the rats was sacrificed and histopathological lesions in the sciatic nerve and tibial nerve were evaluated by morphometry. Neurotoxicity was induced by 2,5-hexanedione, and acetone caused a potentiation of this effect in open field ambulation and rearing and in the rotarod test. In the pathological evaluation, giant axonal swelling was observed after 2,5-hexanedione and 2,5-hexanedione plus acetone. In nerve fibre cross sections, a significant change of the distribution of fibre area size was observed in animals treated with 2,5-hexanedione. Aggravation of the lesions was seen in rats treated with both 2,5-hexanedione and acetone. The other half of the animals was used to study the reversibility of the neurotoxic effects within a dose-free period of 10 weeks. Reversibility of the effect on ambulation was complete within the recovery period, but the effects on rearing and balance in the rotarod test were only reversible within the 10 weeks in the 2,5-hexanedione-treated rats and not in the combined 2,5-hexanedione and acetone-treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Food intake increases the relative oral bioavailability of vanoxerine

Each of 12 healthy male subjects received single oral doses of 100 mg vanoxerine (GBR 12909), a dopamine reuptake inhibitor with potential antidepressant activity, on three different occasions (fasting, after a low-fat meal and after a high-fat meal) according to a randomized, cross-over design. The mean tmax value increased from 0.82 h after fasting to 1.44 h after a low-fat meal and to 2.46 h after a high-fat meal. Only modest food effects were seen on mean Cmax values (55 nM, 52 nM and 84 nM, after fasting, after the low-fat meal and after the high-fat meal, respectively) but values of AUC up to the last measurable concentration (AUC(0,t)) increased by 76% (from 110 to 194 nM h) after the low-fat meal and by 255% (from 110 to 391 nM h) after the high-fat meal compared with fasting. All of these effects were statistically significant except for the differences in tmax and Cmax between fasting and the low-fat meal. The mechanism of these changes is unclear, but it seems likely that food may lower the first-pass metabolism of vanoxerine, as has been shown for other lipophilic basic drugs.

Educational outcome of neonatal intensive care graduates

Studies of developmental outcome of neonatal intensive care unit graduates have generally been limited to the first 2 to 3 years of life, with outcome determined by psychometric tests. This study followed neonatal intensive care unit graduates born 1975 through 1983 (n = 457) into the public school system and compared their educational outcomes with those of newborn nursery graduates (n = 656). Outcomes were evaluated by placement in four academic categories: regular classroom, academic problems, speech/language impairment, and major impairment. Educational outcomes for children of both groups were essentially the same. Their placement in the four academic categories were equally affected by nonmedical variables, primarily income (below/above poverty level), race, and sex. Seventy percent of poverty-level children were in one of the three problem categories, compared with 40% of children above poverty level. Neither neonatal intensive care unit treatment nor low birth weight were major predictors of educational outcome. The only clear-cut neonatal intensive care unit effect occurred among children born with sensory or physical impairments. Therefore, in order to reduce poor educational outcomes, follow-up and intervention programs should be targeted primarily to children with diagnosable handicaps and from minority, low-income families.

Infertility in rats induced by 2,5-hexanedione in combination with acetone

The morphological changes as well as the functional consequences for the reproduction of the testis-injuring effect of 2,5-hexanedione (2,5-HD) were evaluated in rats. The potentiation by acetone and the reversibility of the effects was also studied. Male rats were dosed for 6 weeks with 0, 0.13%, 0.25% or 0.50% 2,5-HD alone or in combination with 0.50% acetone in the drinking water. During the last week of treatment the fertility of half of the treated males was studied by introducing each of them to a non-treated female rat, after which the number of matings, pregnancies and foetuses was examined. In order to evaluate the degree of reversibility of the effect on testis the same examination was made in the other half of the males after a 10 weeks dose-free period. The weight and morphology of testis from all the males was studied. The weight of testis, testis tubuli diameter and fertility was reduced by 2,5-HD and further reduced in groups dosed with 2,5-HD, 0.25% and 0.50% plus acetone 0.50%. Combined administration of acetone and 2,5-HD caused a potentiation comparable to the effect of the double dose of 2,5-HD. Minor changes were reversible within the 10 weeks dose-free period, whereas infertility and other severe changes in the highest combined group were non-reversible within this period. The number of matings was unaffected. It is concluded that 2,5-HD has a testis-injuring effect, which in high doses and combined with acetone causes non-reversible infertility and that testis is more sensitive than the nerve tissue to 2,5-HD.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of 2,5-hexanedione alone and in combination with acetone on radial arm maze behavior, the "brain-swelling" reaction and synaptosomal functions

A multidisciplinary study to investigate 2,5-hexanedione (2,5-HD)-induced CNS-neurotoxicity and its proposed potentiation by acetone (AC) was conducted. Neurobehavioral testing, estimation of the brain-swelling reaction, neuropathological and morphometric measurements as well as synaptosomal 5-hydroxytryptamine (5-HT) uptake were evaluated. Male Wistar rats were exposed through their drinking water, for seven weeks, either to 0.5% 2,5-HD alone or to 0.5% 2,5-HD in combination with 0.5% AC. This 2,5-HD dose is known to cause neurotoxicity in the peripheral nervous system. Exposed animals were compared to a control group that received tap water. Acquisition but not performance of spatial learning, as measured in the radial 8-arm maze, was significantly inhibited by the coexposure to 2,5-HD and AC. Brain weights of rats exposed to 2,5-HD alone and to 2,5-HD and AC in combination, were slightly, albeit significantly, reduced. Synaptosomal high-affinity 5-HT uptake rate and uptake capacity were significantly reduced by 2,5-HD alone and in combination with AC. The morphometric results are reported in a companion paper. In conclusion, the present findings indicate that 2,5-HD is a CNS-neurotoxicant. The hypothesis about AC potentiation of 2,5-HD CNS-neurotoxicity was supported.

Total number and mean cell volume of neocortical neurons in rats exposed to 2,5-hexanedione with and without acetone

The toxicological effects of 2,5-hexanedione (2,5-HD) alone and combined with acetone on the number and size of neurons in the cerebral cortex of rats were evaluated with stereological techniques. Thirty rats were equally divided into three groups: One control, one receiving 0.5% 2,5-HD, and one receiving 0.5% 2,5-HD and 0.5% acetone in the drinking water for seven weeks. Unbiased estimates of the total number of neocortical neurons, as well as the mean neuronal nuclei and cell body volumes were obtained from systematically sampled 3.5-microns sections. The total number of neurons in the 2,5-HD group was significantly smaller than the control group (p less than 0.05, one-tailed t-test). Both test groups showed significant changes in the mean cell body volume: Compared with the control group, animals exposed to 2,5-HD had 11% smaller cell body volumes while animals exposed to 2,5-HD and acetone had 13% larger cell body volumes. These data represent the first unbiased estimation of mean cell volume in toxicology. We propose the nucleator method as an efficient and accurate tool for estimating quantitative changes in toxicological research.

Irreversible effects in rats of toluene (inhalation) exposure for six months

The irreversible CNS effects of six months' exposure to toluene (0, 500, and 1500 p.p.m.) in rats was studied applying a multi-disciplinary approach. After an exposure-free period, neurobehavioural, morphometric, pathological, and biochemical examinations were performed. No neurobehavioural or gross pathological changes were found. Morphometric measurements did not show loss of neurones. At 500 p.p.m. the mean nuclear volume and mean perikaryonal volume and the variation of the values of these parameters was increased in the exposed groups compared to the controls. Noradrenaline (NA), dopamine (DA), and 5-hydroxytryptamine (5-HT) levels were significantly changed in various brain regions. It is concluded that this investigation failed to reveal overt toluene-induced CNS-neurotoxicity, however, certain irreversible effects were found which further add to the accumulating evidence of the chronic CNS-neurotoxicity of toluene.

Effect of toluene on ethanol preference in rats

The effect of toluene on the preference of ethanol was studied in rats. Toluene was administered orally by stomac tube in doses of 200, 400 or 800 mg/kg daily for 5 weeks or by inhalation at a concentration of 2000 p.p.m. 6 or 8 hr daily for 5 or 6 days per week for 2 weeks in rats of different age. During toluene inhalation exposure the rats had access to either tap water or ethanol-containing water (6 or 10%). After the exposure and during oral administration the rats had access to both ethanol-free and ethanol-containing water. Toluene inhibited the body weight gain in the highest oral dose group and in rats exposed to toluene and forced to drink ethanol in the inhalation experiments. In these experiments, the intake of fluid was reduced in the exposure period in rats forced to drink ethanol-containing water and further reduced in rats exposed to both ethanol and toluene. Exposure to toluene alone increased the fluid consumption. The preference of ethanol defined as consumed ethanol-containing water in per cent of the total water intake was not influenced by oral administration of toluene. It was, however, reduced by toluene given by inhalation to rats forced to drink ethanol-containing water during the exposure period. Toluene exposure alone or forced ethanol intake alone caused in these experiments a short-lasting reduction of the ethanol preference. It is concluded that toluene decreases the preference of ethanol in rats forced to drink ethanol during exposure to toluene.

SCH 23390--a selective dopamine D-1 receptor antagonist with putative 5-HT1 receptor agonistic activity

The selective dopamine D-1 receptor antagonist SCH 23390 has been tested in vitro in the rat fundus model and in vivo in the electrically stimulated flexor reflex model. In the fundus model, SCH 23390 showed a potent agonistic activity compared to that of different 5-HT receptor agonists. Pindolol, 1-propranolol and pirenperone showed no or only weak inhibition of the SCH 23390-induced contractions in the fundus strip whereas methysergide was a potent inhibitor. The 5-HT3 receptor antagonist ICS 205-930 did not induce an inhibitory effect. In the electrically stimulated flexor reflex model in pithed rats, SCH 23390 induced a marked increase of the reflex. This increase was slightly inhibited by a mixed dopamine (DA) D-1/D-2 antagonist cis(Z)-flupentixol and by a specific DA D-2 antagonist YM 09151-2. Different reference antagonists: bicuculline (GABAergic), propranolol (beta-adrenergic), scopolamine (muscarinic), yohimbine (alpha 2-adrenergic), prazosin (alpha 1-adrenergic) were all without an antagonist effect on the SCH 23390-induced increase of the flexor reflex. Ketanserin, a selective 5-HT2 receptor antagonist, showed a weak and short-lasting inhibition of the SCH 23390 effect in high doses, whereas ritanserin showed only 35% inhibition of the SCH 23390-induced flexor reflex at a dose of 1.3 mumol/kg i.v. The mixed 5-HT1/5-HT2 antagonists methiothepin and metergoline showed a marked inhibitory effect at 2.6 mumol/kg i.v. and 3.1 mumol/kg i.v., respectively (1.3 mg/kg i.v.). These findings suggest that SCH 23390 might possess 5-HT1 receptor agonist activity.

Pharmacological profile of a novel class of muscarinic acetylcholine receptor agonists

Some in vivo pharmacological effects of a number of muscarinic acetylcholine receptor agonists containing the bicyclic 4,5,6,7-tetrahydroisoxazolo[4,5-c]pyridin-3-ol (THPO) skeleton were studied in rats and mice. The key compounds O,N-dimethyl-THPO (2) and O-methyl-THPO (4) are bioisosteres of arecoline and norarecoline, respectively. The vasodepressor effects of arecoline and the title compounds in anaesthetized rats gave parallel log dose-response curves. The order of potency of the compounds in this test system was identical with that measured earlier using a guinea-pig ileum preparation, arecoline and 2 being the most active compounds. This order of potency was different from those for the antinociceptive and anticonvulsant effects of the compounds using grid shock and isoniazid antagonism tests, respectively, where O-propargyl-THPO (3) proved to be the most active. The pA2 values for the atropine or scopolamine antagonism of these effects of arecoline and 4 were calculated. The partition coefficients (log P values) of the compounds were measured and shown to conform with their ability to penetrate the blood-brain barrier.

A novel class of conformationally restricted heterocyclic muscarinic agonists

A series of conformationally restricted compounds containing the 4,5,6,7-tetrahydroisoxazolo[4,5-c]pyridin-3-ol (THPO) skeleton, including O-methyl-THPO (10a) and O,5-dimethyl-THPO (11a), were synthesized. The compounds were designed by bioisosteric replacement of the methyl ester groups of the muscarinic cholinergic agonists norarecoline and arecoline by the 3-methoxyisoxazole group, and their interactions with central and peripheral muscarinic receptors were tested in vitro. The compounds 10a, 11a, O-ethyl-THPO (10b), O-propargyl-THPO (10j), and O-ethyl-5-methyl-THPO (11b) were inhibitors of the binding of the muscarinic mustard [3H]PrBCM to rat brain membranes with an increasing order of potency. There was, however, a very low degree of correlation between these binding data and the effects of the compounds on peripheral (ileal) muscarinic receptors, where 11a, 10j, 11b, and 10a were agonists with a decreasing order of potency, whereas O-isopropyl-THPO (10e) showed antagonistic effects. The relatively low pKa values of the compounds (7.5-7.7 for compounds with secondary and 6.1-7.0 for compounds with tertiary amino groups) are likely to allow the compounds to penetrate the blood-brain barrier.

Microscopic epidural lesions in goats given repeated epidural injections of morphine: use of a modified autopsy procedure

Epidural catheterization was performed in six goats. Five days later either saline or 20 mg (5 mg/ml) preservative free morphine was injected epidurally once daily for 8 days. The goats were sacrificed 4, 24 or 48 hours after the last injection. The lumbar part of columna was removed in toto for microscopic examination of the spinal cord and the entire epidural space after decalcification and transverse sectioning. After saline, minimal changes including a fibrous membrane surrounding the catheter, scattered fat cell necrosis, scattered small focal cell infiltrations and occasionally focal haemorrhages were seen. After morphine the changes were considerably more severe including diffuse cellular inflammatory reaction in the epidural space, fat cell necrosis, occasionally focal exudative inflammation and chronic inflammatory reaction in the vicinity of the fibrous membrane demarcating position of the catheter. It is concluded that the present modified autopsy procedure permits microscopic examination of the epidural space. It has been shown that repeated administration of morphine caused tissue damage in the epidural space of goats. The human predictability of the results obtained is unknown. However, the results are encouraging for investigations with similar procedure in humans.

Neurotransmitter-role of VIP in non-adrenergic relaxation of feline myometrium

The feline myometrium is heavily innervated by VIP-containing nerve fibres. Transmural electrical stimulation (10 Hz, 2 msec, 150 mA) of muscle strips from feline myometrium in the presence of adrenoreceptor blocking agents caused a muscle relaxation. The smooth muscle relaxation was accompanied by a significant increase in immunoreactive VIP in the superfusate. Both the VIP release and the relaxation were completely annulled by tetrodotoxin, a selective blocker of axonal conduction. Furthermore, passive immunoneutralization with antiserum against VIP markedly reduced the smooth muscle relaxation induced by electrical stimulation. In the light of the previously demonstrated smooth muscle relaxant effect of VIP, the present findings indicate that the peptides may participate as neurotransmitter in non-adrenergic relaxation of the feline myometrium.

Reduction in locomotor activity of arthritic rats as parameter for chronic pain: effect of morphine, acetylsalicylic acid and citalopram

Arthritis was induced in rats by plantar injection of a suspension of killed mycobacteria in Viscoleo. Non-treated rats served as controls. The locomotor activities of the rats were measured weekly during the following four weeks. The exploratory activity was determined in the daytime in activity cages and spontaneous locomotor activity was measured during the night in the same cages. From one week to four weeks after treatment in one hind paw the arthritic rats showed significantly lower exploratory activity than the control rats, whereas the spontaneous locomotor activity in the arthritic rats was not significantly reduced. After treatment in two hind paws both activities were significantly smaller in the arthritic group than in the control group. The low exploratory activity level of the arthritic rats was not changed by acetylsalicylic acid but was significantly increased by morphine and citalopram in doses which did not influence the exploratory activity of the control rats. The results suggest that reduction of the locomotor activity of arthritic rats might be a reliable parameter for chronic pain.

5-HT-uptake inhibition potentiates antinociception induced by morphine, pethidine, methadone and ketobemidone in rats

The effect of the specific 5-HT-uptake inhibitor citalopram on the antinociception induced by morphine, pethidine, methadone and ketobemidone was examined in rats by means of the hot plate test. Further the 5-HT-uptake-inhibiting potency of these opioid-receptor stimulants was examined in vitro in rat brain synaptosomes. In doses devoid of antinociceptive activity, citalopram in a dose-dependent manner potentiated the antinociception induced by the four opioid analgesics. The potentiation of the ketobemidone-induced antinociception was not influenced by the spasmolytic agent A 29 (N,N-dimethyl-3,3-diphenyl-1-methylallylamine) which together with ketobemidone constitutes the active substances in Ketogan. The 5-HT-uptake-inhibiting potencies of the opioid receptor stimulants were from 21 to more than 56000 times lower than that of citalopram, the order of potency being methadone greater than pethidine greater than ketobemidone greater than morphine. The results support the suggested role of 5-HT in morphine-induced antinociception and indicate a similar role in the antinociceptive effect induced by other opioid-receptor stimulants.