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Biomedical subjects

S Lindgren

Publications and source records attributed to S Lindgren.

At least 145 records · Page 8Linked to original sources

Stimulant medication use by primary care physicians in the treatment of attention deficit hyperactivity disorder.

Treatment of attention deficit hyperactivity disorder (ADHD), one of the most common behavioral disorders in children in the United States, remains controversial because of concern about stimulant medication use. Extending a previous study of pediatricians, the present study surveyed a random national sample of family practitioners and then directly screened 457 patients of 10 pediatricians and family practitioners in two small midwestern cities. Responses to the national survey indicated that stimulant medication remains the main treatment prescribed by primary care physicians for children with ADHD. In the direct patient screening, the prevalence of ADHD diagnoses was 5.3% (pediatricians) and 4.2% (family practitioners) of all elementary-school-aged children screened. Eighty-eight percent of these children were treated with methylphenidate. Although medication was considered an effective treatment by the parents of 85% of the children given the medication, efficacy was unrelated to the accuracy of diagnosis. When explicit DSM-III-R criteria were used, only 72% of those assigned a diagnosis of ADHD by the physicians would have received that diagnosis based on a structured psychiatric interview with the parents and only 53% received that diagnosis based on teacher report of symptoms, even when the child was not receiving medication. Although the majority of physicians (in both the surveys and the direct screenings) reported using at least some behavioral treatments with their patients, parents reported infrequent use of nonpharmacologic forms of therapy, such as behavior modification. These data thus indicate a relatively modest rate of stimulant medication use for ADHD, but a serious underuse of systematic behavioral treatments in primary care.(ABSTRACT TRUNCATED AT 250 WORDS)

Attention Deficit Disorder with Hyperactivity↗

Relaxant effects of the selective phosphodiesterase inhibitors milrinone and OPC 3911 on isolated human mesenteric vessels.

Several new positive inotropic drugs with vasodilating properties for which a major mechanism of action is believed to be inhibition of phosphodiesterase (PDE) have been introduced in the treatment of congestive heart failure. Hydrolysis of cyclic nucleotides is catalyzed by multiple forms of PDE, which may vary between organs and cell-types. These enzymes can be selectively inhibited by various agents, theoretically making it possible to produce tissue-selective responses. An enzyme, which belongs to a subclass of cGMP inhibited low Km cAMP PDE, was recently purified from rat adipose tissue. The enzyme was specifically and potently inhibited by the cilostamide derivative OPC 3911 (OPC) and milrinone (mil). We studied the relaxant effects of OPC and mil on isolated human mesenteric arteries and veins in vitro. In preparations contracted by noradrenaline (NA), both agents produced about 60% maximum relaxation; OPC was 3-4 times more potent than mil. Both OPC and mil caused rightward displacement of the NA concentration-response curve and depressed the maximum responses. Arteries, as compared to veins, were more sensitive to this inhibition of NA contraction. Both drugs relaxed arteries contracted by 30 mM K+, but not 127 mM K+; maximum relaxation was between 60 and 70%. OPC was 10 times more potent than mil. The interactions between mil/OPC and isoprenaline, forskolin and ouabain were also studied. In preparations pretreated with isoprenaline or forskolin, the relaxant effects of mil and OPC were additive to those of isoprenaline and forskolin. Ouabain pretreatment did not affect the actions of the phosphodiesterase inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Accelerated nonproteolytic cleavage of C3 in plasma from patients with primary biliary cirrhosis.

Complement 3 (C3) with decreased net charge and altered immunoreactivity was detected by crossed immunoelectrophoresis when EDTA plasma from patients with primary biliary cirrhosis was incubated in vitro after reconstitution with Ca++ and Mg++. The alpha and beta chains of this C3 were intact. C3 with decreased net charge was not detected in patients' fresh plasma. Similar C3 alterations were obtained after reaction between native C3 in serum from healthy persons or purified C3 nucleophiles that induce cleavage of the single thioester bond in the alpha chain of C3. This C3 alteration was unchanged when the reaction occurred in the presence of protease inhibitors. The electrophoretically slow C3 fraction was labile in serum on further proteolytic cleavage of C3. It is suggested that accelerated nonproteolytic C3 cleavage in patients with primary biliary cirrhosis facilitates subsequent binding of C3 to C3b receptors and targets of complement attack.

Calcium↗

Dopamine mediated behavior and GABA influence.

The possibility of interactions between GABA and dopaminergic central nervous mechanisms in the expression of spontaneous behavior was investigated using the behavior pattern shown by male rats in an exploratory test situation. The present study corroborates the facilitatory action of low doses of the dopamine agonist apomorphine on the investigative activity element of the male rats exploratory behavior pattern, as shown previously. In addition it was found that the GABA agonist baclofen in different doses (1.2-4.8 mg/kg IP) selectively increased this activity. Pretreatment with a submaximal dose of baclofen (1.2 mg/kg) potentiated the effect of apomorphine (25 micrograms/kg), indicating that baclofen has the same effect on behavior as presynaptically active dopamine agonists. Thus GABA mechanisms might influence dopamine mediated behavior. The investigative activity which previously has been considered to reflect the adaptive state of an animal is suggested to be influenced by a changed activity in GABA neurons, DA neurons or an interaction between these two systems in the various brain structures involved in the expression of this behavior.

Animals↗

Breed-specific dog-dandruff allergens.

Fifty-one patients with clinical history of dog allergy were skin prick tested with eight individual standardized dog breed-allergen preparations, one mixed breed-allergen preparation (Poodle/Alsatian), dog-serum albumin, and histamine hydrochloride, 1 mg/ml. All extracts were characterized by crossed immunoelectrophoresis and crossed radioimmunoelectrophoresis with a pool of sera from patients clinically sensitive to dog. The dog-breed extracts contained common antigens/allergens, as well as components represented only in one or two dog-breed extracts. The concentration corresponding 1000 BU/ml varied from 16 to 100 micrograms of protein per milliliter. The sensitivity of skin prick test was 67% to 88% for the various dog breed-allergen preparations, but only 18% for dog-serum albumin. Significant difference between the skin test response to different dog breed-allergen preparations indicating dog breed-specific allergens was obtained in 15% of the patients. There was no significant correlation between skin prick test results and symptoms related to a specific dog breed.

Adolescent↗

Clinical and immunological features of Sjögren's syndrome in patients with primary biliary cirrhosis with emphasis on focal sialadenitis.

Serological and pathological findings in 21 patients with primary Sjögren's syndrome (primary SS) were compared with those in 32 patients with primary biliary cirrhosis (PBC). In ELISA, anti-SS-B/La antibodies were detected in sera from 14 (67%) of the patients with primary SS, but only from 12 (38%) of those with PBC. With the Ouchterlony test, anti-SS-A/Ro antibodies were found in sera from 15 (71%) of the primary SS patients, but in no PBC patient. Of those PBC patients investigated prospectively with objective tests, four of 11 (36%) had keratoconjunctivitis sicca, and five of 15 (33%) had pathological sialometry results. In contrast, all PBC patients but one (i.e., 14 of 15 or 93%) showed evidence of focal sialadenitis. In immunochemical study of PBC patients, IgM immunoreactivity was found in the stroma, particularly adjacent to excretory ducts and acini in salivary glands (5 of 5), whereas no such IgM deposits were observed in patients with primary SS (3 of 3), nor in healthy controls (n = 20). We conclude that the frequency of anti-SS-A/Ro and anti-SS-B/La antibodies in serum is lower in PBC patients than in patients with primary SS. The incidence of focal sialadenitis is high in PBC, though only one third of the PBC patients studied here showed clinical evidence of glandular dysfunction. With immunochemical techniques, sialadenitis associated with PBC is distinguishable by its significant IgM reaction from sialadenitis in primary SS.

Aged↗

Effects of GABAergic drugs on the GABA turnover in the substantia nigra and the corpus striatum of the rat.

Changes in the endogenous GABA concentration and in GABA turnover following GABA receptor stimulation or blockade were studied in the substantia nigra and the corpus striatum of the rat. The GABA agonists, muscimol, baclofen and THIP decreased the accumulation of GABA following inhibition of GABA-alpha-ketoglutaric acid aminotransferase by gamma-acetylenic GABA (GAG) in both structures investigated. Only the effect of muscimol in the substantia nigra was inhibited by the GABA antagonist, bicuculline. Muscimol, baclofen and progabide reduced the disappearance rate of GABA in the substantia nigra following inhibition of the glutamate decarboxylase by 4-deoxypyridoxine. The endogenous GABA concentration was decreased in the corpus striatum following muscimol, THIP or baclofen, probably due to a decreased synthesis of GABA. Smaller effects were seen on the endogenous GABA concentration in the substantia nigra, since both the synthesis and the utilization of GABA were decreased by muscimol and baclofen. Thus, the turnover of brain GABA might be regulated by changes in receptor activity.

Alkynes↗

Lack of effects of apomorphine, haloperidol and clozapine on the synthesis and utilization of brain GABA.

The synthesis of GABA was studied as the accumulation of GABA following inhibition of the GABA-alpha-ketoglutaric acid aminotransferase by gamma-acetylenic GABA (GAG) or gamma-vinyl GABA. The disappearance of GABA was studied by means of inhibition of glutamate decarboxylase by 4-deoxypyridoxine. Systemic administration of the dopamine receptor agonist apomorphine did not change the accumulation or the disappearance of GABA in the substantia nigra and the corpus striatum of the rat. However, a very high dose of apomorphine somewhat increased the GAG-induced GABA accumulation in the corpus striatum. The dopamine receptor antagonists haloperidol and clozapine did not modify the accumulation and disappearance of GABA in the two structures, except for a slight decrease in the GAG-induced GABA accumulation in the substantia nigra. Following an acute hemisection, the neural connections between the substantia nigra and the corpus striatum are interrupted on one side of the brain. Apomorphine did not influence the accumulation or the disappearance of GABA in the substantia nigra and in the corpus striatum on the sectioned side of the brain. These results indicate that the synthesis and the utilization of GABA in the two structures studied are not influenced to any greater extent by changes in dopamine receptor activity.

Animals↗

Effect of cricopharyngeal myotomy on pharyngoesophageal function: pre- and postoperative cineradiographic findings.

The pre- and postoperative cineradiographic findings in 14 dysphagic patients who underwent cricopharyngeal myotomy were compared. The reason for the operation was Zenker's diverticulum (7 patients), lack of cricopharyngeal coordination (5 patients), or a cervical esophageal web (2 patients). After the operation the function of the epiglottis, laryngeal vestibule, and pharyngeal constrictors was unaltered (11 patients) or improved (3 patients), although 4 cases showed residual impression due to the cricopharyngeal muscle. Postoperatively, 9 patients developed defective peristalsis and 10 had impaired tonicity of the cervical esophagus. It is concluded that myotomy alters the motor function of the pharyngoesophageal segment considerably. Moreover, certain functions of the pharynx proper are changed by this procedure.

Aged↗