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Biomedical subjects

M Davis

Publications and source records attributed to M Davis.

At least 289 records · Page 16Linked to original sources
PubMed1994

Measures of salivary secretory immunoglobulin A and state anxiety after a nursing back rub.

This study examined the effects of a 10-minute nursing back rub on salivary secretory immunoglobulin A (s-IgA) and state anxiety in well older adult subjects. A control group (n = 14) received no intervention, and an experimental group (n = 18) received a slow stroke effleurage back rub. All subjects initially completed the state portion of the Spielberger State/Trait Anxiety Inventory (STAI) and provided a timed, nonstimulated saliva sample. Control subjects lay positioned in bed for 10 minutes, and experimental subjects received the back rub. Both groups then provided a second saliva sample and completed the STAI again. Anxiety scores decreased for both groups, but not significantly, and s-IgA concentration increased in the experimental group. This study provides rationale for further research into the holistic benefits of the nursing back rub and should encourage nurses to continue to provide caring touch interventions to patients.

Adult↗
PubMed1994

Human envenomation from a wandering garter snake.

Garter snake bites are generally innocuous to human beings. We report a case of human envenomation from the Wandering Garter snake (Thamnophis elegans vagrans). The patient, who was bitten on his right third fingertip, rapidly developed local edema, ecchymosis, and hemorrhagic vesicles. Systemic signs and symptoms did not develop. The clinical picture was similar to that in three previous patients with Thamnophis envenomation in that clinical signs followed a prolonged bite. Thamnophis species have Duvernoy's glands, which may be analogous to venom glands in Crotalidae (pit viper) species. The progressive local effects produced by secretions of these glands may be confused with early Crotalidae envenomation.

Adolescent↗
PubMed1994

Pre- and posttraining infusion of N-methyl-D-aspartate receptor antagonists into the amygdala impair memory in an inhibitory avoidance task.

Involvement of amygdaloid N-methyl-D-aspartate (NMDA) receptors in memory processes was investigated. Rats with cannulas implanted in the basolateral amygdala were trained on a 1 trial step-through inhibitory avoidance task and tested for 24-hr retention. Pretraining infusion of 2-amino-5-phosphonovaleric acid (APV) into the amygdala, but not striatum or hippocampus, produced a dose-dependent retention deficit, which was attenuated by immediate posttraining intra-amygdala infusion of NMDA. Posttraining APV infusion also caused a dose- and time-dependent retention deficit. Pretest APV infusion had no effect on performance in the retention test. Further, pre- or posttraining infusion of 5.0 micrograms APV failed to affect acquisition and retention in the Morris water maze task. These findings suggest that amygdala NMDA receptors are normally activated by aversive training and play a critical role in memory formation for affective experience.

2-Amino-5-phosphonovalerate↗
PubMed1994

Treatment of endophthalmitis after cataract extraction.

BACKGROUND: A series of 34 patients was prospectively treated for postoperative endophthalmitis according to a specific protocol. The data are from the pilot study performed before initiation of the Endophthalmitis Vitrectomy Study (EVS). METHODS: Patients with bacterial endophthalmitis that developed within 6 weeks of cataract extraction received intravitreal amikacin and vancomycin, subconjunctival and topical antimicrobials and corticosteroids, and systemic corticosteroids. All patients had diagnostic samples removed from the aqueous and vitreous, with randomized assignment to immediate vitrectomy versus vitreous tap and treatment with or without intravenous antibiotics. Outcome was evaluated 3 and 9 months after treatment. RESULTS: At the 9-month visit, visual acuity was 20/50 or better in 49% of all eyes, 20/200 or better in 79%, and 5/200 or better in 91%. Media clarity was such that a "20/40 or better view" of the retina was present in 71% of patients at 3 months and in 97% at 9 months. CONCLUSION: This is one of the largest series of patients with postoperative endophthalmitis treated and evaluated under a prospective protocol and without selection bias. Each of the options used in this study to treat postoperative endophthalmitis may result in good visual results.

Aged↗
PubMed1994

Mannitol revisited.

Investigation into the use of osmotic therapy for ICP reduction began in 1919. Mannitol is the osmotic agent currently in use. Mannitol's effectiveness in reducing ICP has been shown. Osmotic therapy using mannitol reduces ICP by mechanisms that remain unclear. Mannitol is thought to decrease brain volume by decreasing overall water content, to reduce blood volume by vasoconstriction and to reduce CSF volume by decreasing water content. Mannitol may also improve cerebral perfusion by decreasing viscosity or altering red blood cell rheology. Lastly, mannitol may exert a protective effect against biochemical injury. The most common complications of therapy are fluid and electrolyte imbalances, cardiopulmonary edema and rebound cerebral edema. Nursing care of the patient receiving mannitol requires vigilant monitoring of electrolytes and overall fluid balance, and observation for the development of cardiopulmonary complications in addition to neurologic assessment.

Brain Injuries↗
PubMed1994

Long-term safety of treatment with recombinant human granulocyte colony-stimulating factor (r-metHuG-CSF) in patients with severe congenital neutropenias.

Congenital neutropenias include a heterogenous group of diseases characterized by a decrease in circulating neutrophils. In phase I/II/III studies in patients with severe congenital and cyclic neutropenia, treatment with recombinant human granulocyte colony-stimulating factor (r-metHuG-CSF) resulted in a rise in the absolute neutrophil counts (ANC) and a reduction in infections. We report the effects of long-term safety of subcutaneous r-metHuG-CSF administration in 54 patients (congenital n = 44. cyclic n = 10) treated for 4-6 years. A sustained ANC response was seen in 40/44 severe congenital neutropenia patients and 10/10 cyclic neutropenia patients. Two patients required an increase of > 25% in dose to maintain a clinical response; one patient became refractory to therapy. A significant decrease in the incidence of severe infections and the need for intravenous antibiotics was noted. Significant adverse events noted which may or may not be related to therapy included: osteopenia (n = 15), splenomegaly (n = 12), hypersplenism (n = 1), vasculitis (n = 2), glomerulonephritis (n = 1), BM fibrosis (n = 2), MDS/leukaemia (n = 3), and transient inverted chromosome 5q with excess blasts (n = 1). R-metHuG-CSF has been well tolerated in the majority of patients and resulted in a long-term improvement in their clinical status.

Adolescent↗
PubMed1994

Geobacter sulfurreducens sp. nov., a hydrogen- and acetate-oxidizing dissimilatory metal-reducing microorganism.

A dissimilatory metal- and sulfur-reducing microorganism was isolated from surface sediments of a hydrocarbon-contaminated ditch in Norman, Okla. The isolate, which was designated strain PCA, was an obligately anaerobic, nonfermentative nonmotile, gram-negative rod. PCA grew in a defined medium with acetate as an electron donor and ferric PPi, ferric oxyhydroxide, ferric citrate, elemental sulfur, Co(III)-EDTA, fumarate, or malate as the sole electron acceptor. PCA also coupled the oxidation of hydrogen to the reduction of Fe(III) but did not reduce Fe(III) with sulfur, glucose, lactate, fumarate, propionate, butyrate, isobutyrate, isovalerate, succinate, yeast extract, phenol, benzoate, ethanol, propanol, or butanol as an electron donor. PCA did not reduce oxygen, Mn(IV), U(VI), nitrate, sulfate, sulfite, or thiosulfate with acetate as the electron donor. Cell suspensions of PCA exhibited dithionite-reduced minus air-oxidized difference spectra which were characteristic of c-type cytochromes. Phylogenetic analysis of the 16S rRNA sequence placed PCA in the delta subgroup of the proteobacteria. Its closest known relative is Geobacter metallireducens. The ability to utilize either hydrogen or acetate as the sole electron donor for Fe(III) reduction makes strain PCA a unique addition to the relatively small group of respiratory metal-reducing microorganisms available in pure culture. A new species name, Geobacter sulfurreducens, is proposed.

Acetates↗
PubMed1994

AIDS and behavioural risk factors in women in inner city Baltimore: a comparison of telephone and face to face surveys.

STUDY OBJECTIVE: The study aimed to investigate the influence the mode of administration of a questionnaire (telephone or face to face) on reports of sexual behaviour and attitudes of HIV risk among woman of reproductive age. DESIGN: Two cross sectional surveys--one, a modified random digit dialing telephone survey, the second, a face to face street sample--were carried out by the same interviewers using similar questionnaires in the same neighbourhoods. SETTING AND PARTICIPANTS: Two socially deprived, inner city neighbourhoods of Baltimore City were assessed in early 1990 before a community health intervention was carried out in one of them. Women between 17 and 35 years were surveyed. MAIN RESULTS: Altogether 775 and 416 women in the target age group were interviewed by telephone and face to face methods: the response rates were 66.4% and 77% respectively. Telephone respondents tended to be older, had more education, were more often married, were less likely to live in subsidised housing, and were more likely to report HIV testing. The proportions of respondents who reported a previous abortion and had had a surgical sterilisation were higher among the telephone respondents (34.7% v 24.1% and 26.4% v 20.6%, respectively). With regard to sexual risk behaviour, the only statistically significant differences were found in the proportion who reported having used drugs (10.6% of the face to face v 2.4% of the telephone sample) or alcohol (30.5% v 16.3%) at last sexual intercourse. The observed method effect on these variables remained unchanged after adjusting for age, education, employment, and marital status. This effect was even stronger for a subgroup of face to face respondents who reported not having a telephone at home. The adjusted odds ratios for reporting alcohol consumption and use of drugs at the last sexual encounter in this group compared with the telephone respondents were 3.7 (2.1, 6.6) and 14.1 (5.7, 34.5) respectively. CONCLUSIONS: Despite the socioeconomic bias associated with the mode of data collection, there are only a few differences between the telephone and personal survey methods in reports of sexual behaviour. These differences are mostly concentrated in young women (under 20 years), and in a particularly socioeconomically deprived subgroup identified through telephone ownership.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Geographic patterns of disability in the United States.

Geographic patterns of county prevalence rates of disability benefit receipt are shown for the Social Security Administration's Disability Insurance (DI) and Supplemental Security Income (SSI) programs. Prevalence rates were calculated by dividing each county's December 1990 DI and SSI disability caseloads by the population aged 18-64 for that year in that county. Separate maps were also constructed for men and women recipients. Areas with the highest overall DI prevalence rates included Appalachia, the Southeast Coastal Plains, the Mid-south, northwestern Montana, the coastal counties of Washington, and isolated counties of the Southwest. Areas with the highest SSI prevalence rates included the Mississippi Delta, scattered counties in Oklahoma, the Missouri "Boot Heel," parts of Appalachia, isolated counties in South and North Dakota, the "Four Corners" regions of the Southwest, the Sacramento and San Joaquin Valley regions of California, isolated parts of the upper Great Lakes States, northern Maine, and the coastal region of southwestern Alaska. Disability prevalence rates were also calculated for the overall population and by sex for each of the 10 U.S. Department of Health and Human Services administrative regions.

Adult↗
PubMed1993

Fear-potentiated startle: a neural and pharmacological analysis.

The fear-potentiated startle paradigm has proven to be a useful system with which to analyze neural systems involved in fear and anxiety. This test measures conditioned fear by an increase in the amplitude of a simple reflex (the acoustic startle reflex) in the presence of a cue previously paired with a shock. Fear-potentiated startle is sensitive to a variety of drugs such as diazepam, morphine, and buspirone that reduce anxiety in people and can be measured reliably in humans when the eyeblink component of startle is elicited at a time when they are anticipating a shock. Electrical stimulation techniques suggest that a visual conditioned stimulus ultimately alters acoustic startle at a specific point along the acoustic startle pathway. The lateral, basolateral and central amygdaloid nuclei and the caudal branch of the ventral amygdalofugal pathway projecting to the brainstem are necessary for potentiated startle to occur. The central nucleus of the amygdala projects directly to one of the brainstem nuclei critical for startle and electrical stimulation of this nucleus increases startle amplitude. Chemical or electrolytic lesions of either the central nucleus or the lateral and basolateral nuclei of the amygdala block the expression of fear-potentiated startle. The perirhinal cortex, which projects directly to the lateral and basolateral amygdaloid nuclei, plays a critical role in the expression of fear-potentiated startle using either visual or auditory conditioned stimuli. These latter amygdaloid nuclei may actually be the site of plasticity for fear conditioning, because local infusion of the NMDA antagonist AP5 into these nuclei blocks the acquisition of fear-potentiated startle. On the other hand, the expression of fear-potentiated startle is blocked by local infusion of the non-NMDA ionotropic antagonist CNQX or the G-protein inactivating toxin, pertussis toxin, but not by AP5. Finally, we have begun to investigate brain systems that might be involved in the inhibition of fear. Local infusion of AP5 into the amygdala was found to block the acquisition of experimental extinction, a prototypical method for reducing fear. We have also established a reliable procedure for producing both external and conditioned inhibition of fear-potentiated startle and hope to eventually understand the neural systems involved in these phenomena.

Animals↗
PubMed1993

NMDA and non-NMDA antagonists infused into the nucleus reticularis pontis caudalis depress the acoustic startle reflex.

The neural pathway that mediates the acoustic startle reflex has been proposed; however, the pharmacology underlying this reflex is less well known. The present study examined the role of excitatory amino acid receptors at the level of the nucleus reticularis pontis caudalis, a brainstem nucleus obligatory for the whole body startle reflex and implicated as the locus where extrinsic systems such as the amygdala may act to modulate acoustic startle. Twenty-nine rats, chronically implanted with bilateral cannulae aimed at the nucleus reticularis pontis caudalis, were tested to assess the effects of gamma-D-glutamylglycine (DGG), DL-2-amino-5-phosphonopentanoic acid (AP5), and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) on the amplitude of the acoustic startle reflex. Local infusion of each of the 3 compounds significantly reduced startle amplitude by as much as 70-80%. AP5 and CNQX attenuated startle over a dose range which indicated that the reticularis pontis caudalis may be much more sensitive to these compounds than other nuclei along the primary startle pathway. These results suggest that, at the level of the nucleus reticularis pontis caudalis, an excitatory amino acid neurotransmitter may mediate acoustic startle, and that both NMDA and non-NMDA receptor subtypes may be important for the expression of the acoustic startle reflex.

2-Amino-5-phosphonovalerate↗
PubMed1993

The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus.

BACKGROUND: Long-term microvascular and neurologic complications cause major morbidity and mortality in patients with insulin-dependent diabetes mellitus (IDDM). We examined whether intensive treatment with the goal of maintaining blood glucose concentrations close to the normal range could decrease the frequency and severity of these complications. METHODS: A total of 1441 patients with IDDM--726 with no retinopathy at base line (the primary-prevention cohort) and 715 with mild retinopathy (the secondary-intervention cohort) were randomly assigned to intensive therapy administered either with an external insulin pump or by three or more daily insulin injections and guided by frequent blood glucose monitoring or to conventional therapy with one or two daily insulin injections. The patients were followed for a mean of 6.5 years, and the appearance and progression of retinopathy and other complications were assessed regularly. RESULTS: In the primary-prevention cohort, intensive therapy reduced the adjusted mean risk for the development of retinopathy by 76 percent (95 percent confidence interval, 62 to 85 percent), as compared with conventional therapy. In the secondary-intervention cohort, intensive therapy slowed the progression of retinopathy by 54 percent (95 percent confidence interval, 39 to 66 percent) and reduced the development of proliferative or severe nonproliferative retinopathy by 47 percent (95 percent confidence interval, 14 to 67 percent). In the two cohorts combined, intensive therapy reduced the occurrence of microalbuminuria (urinary albumin excretion of > or = 40 mg per 24 hours) by 39 percent (95 percent confidence interval, 21 to 52 percent), that of albuminuria (urinary albumin excretion of > or = 300 mg per 24 hours) by 54 percent (95 percent confidence interval 19 to 74 percent), and that of clinical neuropathy by 60 percent (95 percent confidence interval, 38 to 74 percent). The chief adverse event associated with intensive therapy was a two-to-threefold increase in severe hypoglycemia. CONCLUSIONS: Intensive therapy effectively delays the onset and slows the progression of diabetic retinopathy, nephropathy, and neuropathy in patients with IDDM.

Adolescent↗
PubMed1993

Beyond the interpersonal circumplex in group psychotherapy: the structure and relationship to outcome of the Individual Group Member Interpersonal Process Scale.

Development of a new scale to measure patient behavior in group psychotherapy, the Individual Group Member Interpersonal Process Scale (IGIPS), is described. This scale captures clinically important aspects of how patients act in group, including how they respond to the other group members. The IGIPS was applied to videotapes of the first four sessions of seven 15-session outpatient therapy groups (52 patients) in the Mental Health Department of a health maintenance organization. The scale was found to have five factors (Activity, Interpersonal Sensitivity, Comfort with Self, Self-Focus, and Psychological Mindedness). Patient behavior that was moderate on two IGIPS dimensions was connected with better outcome than was that of patients with more extreme behavior in either direction.

Adult↗
PubMed1993

A drug that facilitates glutamatergic transmission reduces exploratory activity and improves performance in a learning-dependent task.

A recently developed benzamide compound which facilitates glutamate receptor-mediated synaptic responses was used to test behavioral consequences of enhanced glutamatergic transmission. The drug was found to depress exploratory activity by rats in a novel environment. At a dose below threshold for causing such effects, drug-treated and control rats exhibited no evident behavioral differences during the acquisition phase of a radial maze experiment. Yet, when tested 2.5 h later, experimental animals were more likely than controls to choose maze arms that had not been entered during the acquisition session, suggesting that the drug enhanced retention of information about prior choices and the maze environment.

Animals↗