Variable bioavailability of papaverine

The plasma concentration curves of papaverine have been studied in nine healthy males and seven patients after administration of single intravenous (80 mg) and oral (80 mg) doses. The bioavailability of the drug was highly variable with a mean of 28% (range 5-99%) but reproducible within the same individual (4 of the volunteers) after a repeated (80 mg) oral dose. The calculated half-life after intravenous administration ranged between 1.2-6.6 hours (mean 3.0). The mean apparent volume of distribution was 3.1 l/kg and the mean total plasma clearance was 836 ml/min. It is concluded that papaverine shows an unacceptable inter-individual variation in the bioavailability after oral administration of 80 mg tablets.

Low-temperature stability of viruses in sludges

Enteroviruses survived for up to 38 days without diminishing in numbers in extended-aeration sludges maintained at 5 degrees C. In oxidation ditch sludges similarly maintained, enteroviruses survived for up to 17 days without diminishing in numbers. The pHs of the sludges in this study were well inside the pH 6 to 8 corridor in which destruction of enteroviruses by the detergents and ammonia present in sludges reportedly does not occur. Unexplained, however, was the survival of large numbers of enteroviruses in sludges at pH 3.5, a pH at which some anionic detergents commonly present in sewage are rapidly virucidal. The long survival of enteroviruses in these sludges at 5 degrees C indicates that such sludges can probably be stored under refrigeration in the laboratory for extended periods while awaiting processing without suffering significant losses in enterovirus numbers.

Long-term administration of 3'-azido-2',3'-dideoxythymidine to patients with AIDS-related neurological disease

3'-Azido-2',3'-dideoxythymidine (AZT) has been administered to 7 patients with human immunodeficiency virus-associated neurological disease: 3 with dementia, 2 with peripheral neuropathy, 1 with dementia and peripheral neuropathy, and 1 with T-10 paraplegia. Six of the patients showed improvement in their neurological dysfunction on being administered AZT, as assessed by clinical evaluation, neuropsychological testing, nerve conduction studies, and/or positron emission tomographic scans. Three of these 6 patients showed sustained improvement 5 to 18 months after the initiation of AZT therapy. These results suggest that certain human immunodeficiency virus-associated neurological abnormalities are at least partially reversible following the administration of antiretroviral therapy and provide a rationale for further studies using antiretroviral chemotherapy.

Low back pain during pregnancy

All pregnant women from a well defined area (the central district of the County of Ostergötland, Sweden) attending antenatal clinics over a period of seven months were interviewed with regard to low back pain during pregnancy. Of 862 women who answered the questionnaires, about half developed some degree of low back pain. Seventy-nine women who were unable to continue their work because of severe low back pain were referred to an orthopedic surgeon for an orthoneurologic examination. The most common reason for severe low back pain was dysfunction of the sacroiliac joints. Physically strenuous work and previous low back pain were factors associated with an increased risk of developing low back pain and sacroiliac dysfunction during pregnancy.

[Experimental research with a new percutaneously insertable and expandable vascular prosthesis]

Restenosis and occlusion are the most common reasons why transluminal balloon angioplasty may fail to provide long-term benefit. To prevent restenosis and occlusion of diseased arteries after angioplasty an arterial endoprosthesis has been developed which is positioned to the balloon of an angioplasty catheter and which consists of a stainless steel pliable and elastic tube. With the inflation of the balloon the endoprosthesis will dilate and give the arterial wall a new mechanical support. This new device has been implanted in 12 experimental dogs in arteries of different size and lumen. The longest patency rate of nine months was observed with the completely developed method.

Effects of different phosphodiesterase-inhibiting drugs on human pregnant myometrium: an in vitro study

The phosphodiesterase (PDE)-inhibiting and smooth muscle relaxing effects of theophylline, enprofylline, papaverine and moxaverine have been studied in vitro on spontaneous contracting human, pregnant myometrium. All drugs showed a close correlation between the PDE-inhibiting and smooth muscle relaxing effect. The order of smooth muscle relaxing potency was papaverine greater than moxaverine greater than enprofylline greater than theophylline. The most potent PDE-inhibitors were moxaverine and papaverine with a 50% PDE-inhibiting concentration (IC50) of 3.3 and 3.8 microM as compared to the least potent PDE-inhibitor, theophylline, with an IC50 of 665 microM. It is concluded that PDE-inhibiting drugs show a close correlation between PDE-inhibiting and relaxing effect on spontaneously contracting pregnant myometrium and that the newly developed drug enprofylline might be of interest in the treatment of premature uterine contractions.

Effects of enprofylline, a new xanthine derivate, on human pregnant myometrium

The recently developed xanthine derivate, enprofylline, was studied in an in vitro system with human pregnant myometrium, in particular its effect on spontaneous myometrial contraction, cyclic adenosine monophosphate content, cyclic adenosine monophosphate protein kinase, and cyclic adenosine monophosphate-and cyclic guanosine monophosphate-dependent phosphodiesterase activity. Enprofylline was shown to be a rather potent smooth muscle relaxant [inhibitory concentration that decreases response by 50% (IC50) = 3 X 10(-5) mol/L] and an almost equally potent cyclic adenosine monophosphate-dependent phosphodiesterase inhibitor (IC50 = 10(-4) mol/L), whereas it was a less potent cyclic guanosine monophosphate-dependent phosphodiesterase inhibitor. Enzyme kinetic studies revealed that enprofylline is a competitive cyclic adenosine monophosphate phosphodiesterase inhibitor. Enprofylline increased the cyclic adenosine monophosphate content in a dose-dependent way with subsequent increased activity of cyclic adenosine monophosphate-dependent protein kinase. It is suggested that enprofylline relaxes myometrial smooth muscles and that this is at least partly the result of interference with the cyclic adenosine monophosphate system.

Cerebral metabolism, anatomy, and cognition in monozygotic twins discordant for dementia of the Alzheimer type

One pair of monozygotic twins discordant for dementia of the Alzheimer type (DAT) was studied using neuropsychological testing, quantitative x-ray computed tomography (QCT) and magnetic resonance imaging (MRI) of the brain. Cerebral glucose metabolism was measured using positron emission tomography (PET) and 2-[18-F]fluoro-2-deoxy-D-glucose (FDG). The affected twin had a seven year history of progressive cognitive impairment and was severely demented. Neuropsychological testing of the affected twin demonstrated marked deficits in all areas of cognitive function. The asymptomatic twin showed some impairment on tests of perceptual organisation and delayed recall. The affected twin had loss of gray matter and ventricular enlargement on QCT and MRI compared with healthy controls (p less than 0.05). He also had frontal and parietal lobe hypometabolism and increased asymmetry of metabolism on PET compared to both his twin and healthy age-matched controls (p less than 0.05). PET, QCT, and MRI distinguished changes in the twin with DAT compared with his brother and healthy controls. Although the subtle neuropsychological abnormalities of the asymptomatic twin may be signs of early DAT, they were not accompanied by any changes in regional cerebral metabolism or brain structure.

Longitudinal change in three brief assessments of SDAT

Previous research has shown that there is considerable interest in the development of brief indices for use in the diagnosis and staging of senile dementia of the Alzheimer's type (SDAT). Examples of such measures include the Blessed Dementia Scale (BDS) and Pfeiffer's Short Portable Mental Status Questionnaire (SPMSQ). A third measure used in the assessment of organic cognitive impairment is the Face-Hand Test (FHT). This study, which was part of a large longitudinal investigation of SDAT, examined the performance of 43 subjects with SDAT and 57 healthy controls over 30 months. The subjects were assessed three times during this period. In addition to the brief measures (BDS, SPMSQ, and FHT) all subjects were rated on a Clinical Dementia Rating (CDR) Scale based on a lengthy clinical interview. The data were analyzed by means of a series of univariate, repeated measures ANOVAs, and discriminant analysis. Results indicate: control scores did not change over time on any of the measures; when classified according to severity of SDAT, different patterns of performance emerged over time for each measure; and it is difficult to accurately predict progression of SDAT from the three scores.

Response of human-immunodeficiency-virus-associated neurological disease to 3'-azido-3'-deoxythymidine

Four patients with human-immuno-deficiency-virus-associated neurological disease were treated with 3'-azido-3'-deoxythymidine (AZT). Three (two with chronic dementia, and one with chronic dementia and peripheral neuropathy) improved as assessed by clinical examination, psychometric tests, nerve conduction studies, and/or positron emission tomography; there was no improvement in the fourth patient who presented with paraplegia. These results support the hypothesis that certain AIDS-virus-associated neurological abnormalities are reversible by antiretroviral chemotherapy.

Neuropsychological and cerebral metabolic function in early vs late onset dementia of the Alzheimer type

Differences in age at onset of dementia of the Alzheimer type (DAT) have been associated with differences in cognitive impairments and course of the disease. To investigate this, we examined cerebral metabolism and cognitive performance in early and late onset DAT patients, who had equivalent duration and severity of illness. Regional cerebral metabolic rates for glucose were measured in the resting state by positron emission tomography using [18F]2-fluoro-2-deoxy-D-glucose. A cross-sectional analysis showed no significant differences between the two groups in performance on neuropsychological tests, but the early onset patients showed significantly more parietal metabolic dysfunction than did the late onset patients. Longitudinal analysis showed no significant differences between early and late onset patients in rate of cognitive decline over a mean interval of 19 months. Thus, our results do not support the hypothesis of different subgroups in DAT based on age at onset, nor suggest a faster rate of cognitive decline in younger patients.

Stability of metabolic and neuropsychological asymmetries in dementia of the Alzheimer type

We examined right/left asymmetries in cerebral glucose utilization and neuropsychological performance in 16 patients with dementia of the Alzheimer type (DAT) who were studied twice over a mean interval of 15 months. Neuropsychological asymmetry was expressed as the difference between performance on a visuoconstructive task and a language task. Test/retest comparisons showed significant declines on the neuropsychological measures, but no significant changes in the neuropsychological and metabolic asymmetry indices. At both evaluations, significant correlations were found between neuropsychological asymmetry and metabolic asymmetry in frontal and parietal cortex. Individual patterns of metabolic and neuropsychological asymmetry in these patients with DAT seem to be stable.

Neocortical metabolic abnormalities precede nonmemory cognitive defects in early Alzheimer's-type dementia

Neuropsychological function and resting regional neocortical glucose metabolism, as measured by positron-emission tomography, were studied in 22 patients with mild and moderate Alzheimer's-type dementia. Metabolic reductions in the parietal association cortex and increased left-right metabolic asymmetry were observed in patients with mild and moderate degrees of dementia. Five patients with mild dementia had no impairment of neocortically mediated neuropsychological function, yet they demonstrated these same neocortical metabolic abnormalities. Asymmetry of neocortically mediated, neuropsychological functions correlated with metabolic asymmetries in patients with moderate but not mild dementia. These results suggest that physiological dysfunction in the that physiological dysfunction in the association neocortex is evident in early Alzheimer's-type dementia before the neuropsychological consequences of that dysfunction are demonstrable.

Alpha-adrenergic receptors in human myometrium during pregnancy

The distribution and mechanisms of alpha-adrenergic receptors have been studied in myometrial preparations from women delivered by cesarean section at term. With the use of the radioligand tritiated dihydroergocryptine, the number of alpha-adrenergic receptors was 210 fmol/mg of protein in the uterine fundus and 195 fmol/mg of protein in the lower uterine segment. Competition experiments showed that 60% of the alpha-adrenergic receptors had properties as alpha 1-adrenergic receptors and 40% as alpha 2-adrenergic receptors. In vitro tension studies verified the existence of physiologically active alpha 1- and alpha 2-adrenergic receptors in the myometrial preparations. alpha 2-Adrenergic receptor stimulation resulted in lowered levels of intracellular cyclic adenosine monophosphate. The intracellular cyclic adenosine monophosphate was further reduced by additional alpha 1-adrenergic receptor stimulation, probably secondary to an activation of calcium-calmodulin-dependent phosphodiesterase.

Systemic lupus erythematosis presenting as isolated congestive heart failure

We describe a patient with systemic lupus erythematosus, who presented with congestive heart failure. The diagnosis and favorable response to corticosteroid therapy was confirmed by myocardial biopsy and cardiac catheterization.

[Influence of the volume of peridural morphine bolus injections on morphine concentration in the cisterna magna of the dog]

14 dogs received randomly a bolus injection of either 2 mg morphine in 10 ml isotonic saline solution or 2 mg morphine in 1 ml isotonic saline solution epidurally at T6. An epidural infusion of 0.16 mg morphine/0.06 ml/h was applied immediately following the 1 ml bolus injection of morphine. Cisternal cerebellomedullary CSF samples were taken at varying intervals to determine free morphine immunoreactivity by radioimmunoassay. Within 20 min after the 10 ml bolus injection the peak CSF morphine concentration of 3594 +/- 910 ng/ml was reached. Following this, CSF morphine levels decreased exponentially and after 48 h 8 +/- 3 ng/ml were measured. The peak CSF morphine concentration of 139 +/- 51 ng/ml was, however, reached only after 2 h following the 1 ml bolus injection plus the infusion treatment. Despite the additional infused amount of 7.68 mg over 48 h the CSF morphine concentrations decreased also exponentially and after 48 h 16 +/- 4 ng/ml were measured. One may conclude, therefore, that the risk of respiratory depression is negligible under epidural infusion treatment following an initial "Low-Volume"-bolus injection of 2 mg morphine, a recommendable method for treating post-operative pain. High-volume bolus injections of morphine should generally be abandoned in epidural treatment of pain.

Beta-adrenergic receptors in human myometrium during pregnancy: changes in the number of receptors after beta-mimetic treatment

The concentration of available beta-adrenoceptors has been studied in the myometrium of women treated with terbutaline for premature uterine contractions and in an untreated control group. Myometrial strips were taken at cesarean section from the lower uterine segment and the uterine fundus. The concentration of beta-adrenoceptors was determined with a radioligand binding assay. In untreated women we found no difference in the concentration of beta-adrenoceptors in the uterine fundus compared to that in the lower uterine segment. The cyclic adenosine monophosphate production after beta-adrenoceptor agonist stimulation in vitro was equal in both locations. In the terbutaline-treated women, the binding site concentrations in both the fundus and lower uterine segment were lower compared to those in the control group. The decrease was most pronounced in the fundus where receptor concentration was only half that found in the control group. The results suggest that treatment with beta-mimetics causes a desensitization in the beta-adrenoceptor system of human myometrium during pregnancy. This desensitization may partly explain the limited duration of the relaxant effect of beta-mimetics often seen in the treatment of preterm labor.