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Biomedical subjects

S Hall

Publications and source records attributed to S Hall.

At least 289 records · Page 16Linked to original sources
PubMedDate not supplied

Infantile hypertrophic pyloric stenosis after pertussis prophylaxis with erythromcyin: a case review and cohort study.

BACKGROUND: In February, 1999, a local US health department identified a cluster of pertussis cases among neonates born at a community hospital and recommended oral erythromycin for post-exposure prophylaxis for about 200 neonates born at that hospital between Feb 1 and Feb 24, 1999. We investigated a cluster of seven cases of infantile hypertrophic pyloric stenosis (IHPS) that occurred the following month among the neonates who had received erythromycin. METHODS: We obtained a masked, independent review of the IHPS ultrasonography diagnoses, calculated the monthly IHPS incidence, and compared index and historical (1998-99) IHPS cases with respect to several characteristics including erythromycin exposure. We used a retrospective cohort of infants born in January and February, 1999, to investigate further erythromycin exposure and development of IHPS. FINDINGS: An independent review confirmed the ultrasonographic diagnoses of all seven index IHPS cases. All index cases versus none of the historical IHPS cases had been given erythromycin for pertussis prophylaxis. The IHPS rate for infants born in the hospital in February, 1999, was 32.3 per 1000 liveborn infants, representing nearly a seven-fold increase over 1997-98 (relative risk 6.8 [95% CI 3.0-15.7]). Among infants born in January and February, 1999, erythromycin was associated with IHPS (absolute risk 4.5%, relative risk infinity [1.7-infinity]). INTERPRETATION: Neonates receiving oral erythromycin may have an increased risk of IHPS. The risks and benefits of erythromycin for neonatal pertussis prophylaxis should be re-evaluated, and caution should be used in defining risk groups for prophylaxis.

Administration, Oral↗
PubMedDate not supplied

Lactate transfer across the perfused human placenta.

The transfer of lactate across the human placenta was investigated using an in vitro dually-perfused placental preparation. Using a novel technique, the unidirectional flux of L-lactate was found to be linearly dependent on L-lactate concentration. In addition, unidirectional transfer rates were found to be the same in both maternal-to-fetal and fetal-to-maternal directions at the same lactate concentration. Transfer of [14C]L-lactate was decreased by approximately 15 per cent in competition with unlabelled L-lactate. Stereospecificity and permeability experiments demonstrated the existence of a transfer mechanism which could distinguish between the L- and D-isomers of lactate. Our data suggest that, while a stereospecific carrier for lactate exists in the perfused placenta, the bulk of transplacental lactate transfer takes place by non-carrier-mediated diffusion.

Antipyrine↗
PubMedDate not supplied

History of alcohol or drug problems, current use of alcohol or marijuana, and success in quitting smoking.

Previous research suggests higher rates of smoking, and smoking cessation failure, in alcohol- and drug-abusing populations. The present study examined the relationship of alcohol/drug treatment history and current alcohol and marijuana consumption with success in smoking cessation treatment in a smoking clinic population. Participants were 199 smokers; 23% reported a history of alcohol/drug problems, 12.6% reported a history of drug treatment, 78.7% reported alcohol use, and 21.3% reported marijuana use during treatment. Results indicate no significant differences in abstinence rates based on history of alcohol/drug problem or treatment. Differences were found for any current alcohol use but not for marijuana use. Both alcohol use at baseline and any alcohol use during treatment predicted smoking at all follow-up points. Alcohol users had significantly lower quit rates than did participants reporting no use. Neither use of marijuana at baseline nor during treatment predicted outcome. These findings suggest that even low to moderate levels of alcohol consumption during smoking cessation may decrease treatment success.

Adult↗
PubMedDate not supplied

The treatment of severe self-injurious behavior by the systematic fading of restraints: effects on self-injury, self-restraint, adaptive behavior, and behavioral correlates of affect.

Severe self-injurious behavior (SIB) in people with mental retardation is difficult to treat when dangerously frequent or intense responding rules out functional analysis and interventions that permit free responding. This situation is common when restrictive devices, such as straight arm splints, are used. In this study, the effects of introducing flexion into a straight-arm splint, on SIB, self-restraint, adaptive behavior, and behavioral correlates of affect were examined for three individuals with severe mental retardation. Using single-case design methodology, for two individuals self-injury was reduced to zero, while the overall level of restriction was also significantly reduced. From the observed behavioral correlates of affect, there was no evidence of an increase in negative affect with the introduction of the new splint and the fading procedure, but there was evidence of an increase in positive vocalizations. Engagement in activities and social contact were not affected by the introduction of the new splint. The reasons for a decrease in SIB with a corresponding decrease in restriction in the absence of any manipulation of contingencies for SIB are discussed, with particular reference to stimulus control.

Adaptation, Psychological↗
PubMedDate not supplied

A molecular to molar analysis of communicative and problem behaviors.

Few studies have examined the relationship between communicative and problem behaviors that are already present in a behavioral repertoire. In this study, a detailed microanalysis of the antecedents and consequences of aggressive and communicative behavior of a 7-year-old boy was conducted. By using both descriptive and experimental methodologies, the data suggested that problem and communicative behavior were maintained on thin concurrent schedules of social negative reinforcement. A molar analysis of the descriptive data showed that the relative amount of time allocated to each behavior was a function of the relative amount of reinforcement that each behavior accrued. The implications of these findings are discussed in terms of conducting descriptive analyses and for enhancing the efficacy of interventions for problem behavior.

Child↗
PubMedDate not supplied

Aggression and the termination of "rituals": a new variant of the escape function for challenging behavior?

Aggression and stereotyped behaviors are not uncommon among people with intellectual disabilities and they are often treated separately as operant behaviors. In this single case study, it is argued that the function of a young woman's aggressive behavior appeared to be that of avoiding or escaping the termination of a chain of complex stereotyped behavior (or "ritual"). She became aggressive only when this chain of stereotyped behavior was terminated and the aggression appeared to extinguish when it no longer led to escape from the termination of the "ritual". It is suggested that this is an example of a complex interaction between two behaviors and that it illustrates the need for very careful analysis of the functions of challenging behavior. Furthermore, it is proposed that the lengthening list of variables already documented as determinants of challenging behavior (provision of attention (verbal and physical), mechanical restraint, sensory or tangible events, escape from demands or from social attention, denials, escape from intrusive medical procedures, escape from task difficulty) be lengthened to include the possibility of escape from (or avoidance of) the interruption of a chain of complex stereotyped behavior or "ritual".

Adult↗
PubMedDate not supplied

Domoic acid: neurobehavioral and neurohistological effects of low-dose exposure in adult rats.

Adult rats treated IP with domoic acid at 0, 0.22, 0.65, or 1.32 mg/kg were tested for passive avoidance (PA), auditory startle (AS), or conditioned avoidance (CAR) behaviors. Clinical signs were observed only at the 1.32 mg/kg dose level. Within 24 h of dosing, rats surviving a dose of 1.32 mg/kg exhibited transient decreased body weight and exaggerated AS responding. Startle latency and habituation, PA, and CAR were not affected. Examination of brains from six rats per group revealed a subset (2/6) of animals receiving 1.32 mg/kg domoic acid with degenerating neurons in the hippocampal CA1/CA3 subregions and gliosis. The decreased body weight and increased startle suggest a hyperreactivity syndrome possibly related to neuronal degeneration in the hippocampus. In a separate experiment, domoic acid at an IP dose of 0.93 mg/kg was found to produce hypomotility in addition to a decrease in body weight. Both effects were reduced by pretreatment with scopolamine (2 mg/kg), but not with caffeine (30 mg/kg), indicating a possible cholinergic involvement in domoate's toxicity.

Acoustic Stimulation↗
PubMedDate not supplied

The local anesthetic properties and toxicity of saxitonin homologues for rat sciatic nerve block in vivo.

BACKGROUND AND OBJECTIVES: Saxitoxin and its homologues are naturally occurring compounds that block the sodium channel with high potency. They have the potential for providing prolonged duration local anesthesia when coinjected with vasoconstrictors or conventional local anesthetics and are devoid of local neurotoxicity. Here, we compare sciatic nerve block with saxitoxin to those with neosaxitoxin, decarbamoyl saxitoxin, and tetrodotoxin (TTX), in a search for even safer compounds. METHODS: Rats received percutaneous sciatic nerve block with toxins. The compounds were compared in terms of lethality, onset and duration of action for thermal analgesia (hot-plate testing), and motor block (weight-bearing). Data were expressed as medians with 25th and 75th percentiles, and median effective concentrations were determined. RESULTS: The median concentrations at which analgesia of 60 minutes duration was achieved were neosaxitoxin, 34+/-2 micromol/L; saxitoxin, 58+/-3 micromol/L; TTX, 92+/-5 micromol/L; and decarbamoyl saxitoxin, 268+/-8 micromol/L. Similar trends were observed for other measures of effectiveness (block duration of 90 minutes, maximal block), and for lethality so that the therapeutic indices were similar. No toxin had a marked predominance of sensory or motor block. The potency of TTX was intermediate between those of the saxitoxins, and its therapeutic index was slightly better. No difference was observed in time to onset of nerve blockade among the toxins. CONCLUSIONS: Substitutions on the saxitoxin nucleus result in large differences in incidence and duration of block, and toxicity. The therapeutic indices of the saxitoxins are similar; that of TTX is slightly better.

Anesthetics, Local↗
PubMedDate not supplied

Use of clonidine as a component of the peribulbar block in patients undergoing cataract surgery.

BACKGROUND AND OBJECTIVES: This study was designed to determine whether administration of clonidine as a component of a peribulbar block enhanced analgesia increased sedation, improved akinesia, or decreased intraocular pressure. METHODS: A randomized, double-blinded study was undertaken at a University-affiliated tertiary care hospital. Forty outpatients undergoing unilateral cataract surgery by a single surgeon (J.P.) under peribulbar blockade were evaluated. Patients received either 100 microg (1 mL) clonidine or 1 mL preservative-free normal saline mixed with the local anesthetic (7 mL 1% preservative-free lidocaine). A Honan adapter was applied for 10 minutes after block placement. The outcome measures included sedation scores, intraocular pressure (IOP) before and after peribulbar block, need for supplemental block, 24-hour analgesic requirement, and patient satisfaction. RESULTS: There were no differences between groups with respect to pain, sedation, or satisfaction scores. There was no difference with respect to onset of akinesia. This study revealed no significant difference in baseline IOP and postperibulbar IOP. CONCLUSIONS: Clonidine did not alter, in any appreciable way, the perioperative course for patients undergoing cataract operations. We do not recommend clonidine as a component of a peribulbar block in patients undergoing cataract extraction operations.

Adjuvants, Anesthesia↗
PubMedDate not supplied

First-stage autosomal genome screen in extended pedigrees suggests genes predisposing to low bone mineral density on chromosomes 1p, 2p and 4q.

Osteoporosis is characterized by low bone density, and osteopenia is responsible for 1.5 million fractures in the United States annually. In order to identify regions of the genome which are likely to contain genes predisposing to osteopenia, we genotyped 149 members of seven large pedigrees having recurrence of low bone mineral density (BMD) with 330 DNA markers spread throughout the autosomal genome. Linkage analysis for this quantitative trait was carried out using spine and hip BMD values by the classical lod-score method using a genetic model with parameters estimated from the seven families. In addition, non-parametric analysis was performed using the traditional Haseman-Elston approach in 74 independent sib pairs from the same pedigrees. The maximum lod score obtained by parametric analysis in all families combined was +2.08 (theta = 0.05) for the marker CD3D on chromosome 11q. All other combined lod scores from the parametric analysis were less than +1.90, the threshold for suggestive linkage. Non-parametric analysis suggested linkage of low BMD to chromosomes 1p36 (Zmax = +3.51 for D1S450) and 2p23-24 (Zmax = +2.07 for D2S149). Maximum multi-point lod scores for these regions were +2.29 and +2.25, respectively. A third region with associated lod scores above the threshold of suggestive linkage in both single-point and multi-point non-parametric analysis was on chromosome 4qter (Zmax = +2.95 for D4S1539 and Zmax = +2.48 for D4S1554). Our data suggest the existence of multiple genes involved in controlling spine and hip BMD, and indicate several candidate regions for further screening in this and other independent samples.

Bone Density↗
PubMedDate not supplied

Non-prescription complementary treatments used by rheumatoid arthritis patients attending a community-based rheumatology practice.

BACKGROUND: Over 80% of rheumatoid arthritis (RA) patients have used some type of complementary medicine (CM) at some time. Little is known about RA patients' perceptions of the efficacy, hazards and costs associated with CM use relative to physician-prescribed medicine. These data may be helpful in better understanding patients' needs and in improving their care. AIMS: To determine the prevalence and features of CM use among RA patients attending a community-based private rheumatology practice. CM was defined as treatment that was initiated by the patient, excluding treatment that had been prescribed or specifically recommended by their doctor. telephone-administered questionnaire was used to survey a stratified random sample of 200 RA patients who had attended the practice within the preceding year. The main outcome measures were: (i) CM use in the past year, (ii) patient expenditure on CM, (iii) patients' perceptions of CM and (iv) characteristics of patients using CM. RESULTS: One hundred and six patients responded (response rate 53%) and 101 completed the interview. Seventy-four patients (73.3%) had used some form of CM in the past year. There were 68 (67.3%) patients who had utilized complementary therapies and 32 patients (31.7%) who had consulted a complementary practitioner for their RA. The most commonly used treatments were dietary (64 instances) and behavioural/cognitive therapies (45 instances). Prescription medicine was considered more beneficial than either form of CM, and users and non-users of CM held a similar perception of the efficacy of prescription medicine. The median amount spent on RA treatment per month was $A7 (range 0-91) for complementary treatments, $A26 (1-270) for complementary practitioners and $A7 (0-80) for prescription medicine. Women were more likely to have consulted a CM practitioner (OR = 1.5; 95% CI: 1.2-1.9), as were patients who were not receiving a pension (OR = 1.7; 95% CI: 1.1-2.6). CONCLUSIONS: This study confirmed that CM use is prevalent among RA patients attending a community-based private rheumatology practice. Despite lesser perceived benefit, patients spent at least as much money on CM as they did on prescription medicine. These findings suggest that there are other factors motivating the use of alternative treatments.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Developmental levels of interdisciplinary collaborative practice committees.

Establishing interdisciplinary collaborative practice committees has and will be a prime strategy in healthcare. Evaluating the functioning, progress, and outcomes of these committees is important. Defining a mechanism to evaluate interdisciplinary collaborative practice committees should be beneficial. The author presents an easy evaluation tool that can determine the level and functioning of interdisciplinary collaborative practice committees.

Evaluation Studies as Topic↗
PubMedDate not supplied

Tympanostomy tubes: do they significantly benefit the patient?

To gain more information about the role of tympanostomy tubes in the treatment of chronic middle ear effusion, the authors conducted a randomized trial that clearly indicated the short-term advantages of combining the insertion of an Armstrong ventilator tube with paracentesis and fluid aspiration over paracentesis and aspiration alone. A retrospective study of the success rate with three types of tympanostomy tubes (Shepard, Armstrong, and Paparella) was also carried out. The Armstrong tube had the highest success rate.

Child↗
PubMedDate not supplied

Cloning and characterization of an androgen-dependent acidic epididymal glycoprotein/CRISP1-like protein from the monkey.

A cDNA encoding an acidic epididymal glycoprotein (AEG)-like, CRISP1 (cysteine-rich secretory protein) protein from the monkey (Macaca mullata) epididymis has been cloned and sequenced. The monkey AEG (mAEG) has an open reading frame that encodes a protein containing 249 amino acids with a deduced molecular mass of 28 kDa. The mAEG protein sequence is 85% identical to human and 44% identical to mouse CRISP1, including all 16 conserved cysteine residues. mAEG also shows a significant amino acid homology with other CRISP proteins, rat AEG/DE, human TPX1/CRISP2, and guinea pig acrosomal autoantigen 1 (AA1). In addition, mAEG shows somewhat less homology to a toxin from the Mexican beaded lizard and to a human glioma pathogenesis-related protein. Northern blot analysis shows that the mRNA for mAEG is expressed in all the regions of the epididymis except the caput and was not detected in the testis, prostate, seminal vesicle, and brain. In castrated animals, mAEG gene expression in the epididymis is significantly diminished; however, testosterone enanthate replacement restored the normal level of expression, demonstrating that expression of mAEG is androgen dependent. Western blot analysis of monkey epididymal regions using mouse antirecombinant human AEG identified a 28-kDa protein only in the caudal region. Immunohistochemical analysis identified mAEG only in the principal cells of the cauda epididymal epithelium. Immunofluorescence analysis identified mAEG on the principal piece of the sperm tail and as small patches over the middle piece and head regions. The results described in the present study suggest that mAEG (CRISP1) is secreted in the monkey epididymis, regulated by androgens and present on epididymal spermatozoa.

Amino Acid Sequence↗