Search PubMed⌕ Search

Biomedical subjects

C Berry

Publications and source records attributed to C Berry.

At least 55 records · Page 3Linked to original sources
PubMed1996

Addiction versus stages of change models in predicting smoking cessation.

Prospective data from the California Tobacco Surveys (n = 2066) were used to perform a critical test of the Prochaska et al. (1991) stages of change model. When the stages of change model was used as a stand alone predictor, smokers in preparation at baseline were more likely to be in cessation at follow-up than smokers in pre-contemplation at baseline (ORadj = 1.9). When stage membership was combined with baseline measures of addiction including smoking behaviors and quitting history, it was not a significant predictor of future cessation. A prediction equation that combined daily vs. occasional smoking, cigarettes per day smoked, life-time quits of at least a year, and quits of more than 5 days in the previous year discriminated smokers in cessation at follow-up of 1 to 2 years better than did the stages of change model. The area under the ROC curve for the equation based on addiction measures was 69.3% vs. 55.1% for the stages of change. Cessation rates ranged from 7.7% to 35.7% for the four-category addiction equation compared with 15.1% to 24.9% for stages of change model.

California↗
PubMed1996

Detecting hemodialysis vascular access stenosis: a tracking tool.

A tool for tracking indicators of hemodialysis vascular access stenosis is described to facilitate documentation of early signs of stenosis. Prompt notification of the nephrologist, and referral to an interventional radiologist for percutaneous transluminal angioplasty may prevent more costly interventions or hospitalizations, and even loss of the permanent access. Inadequate dialysis and its complications may be avoided by nursing observation and documentation of indicators known to be predisposing factors to hemodialysis vascular access stenosis.

Arteriovenous Shunt, Surgical↗
PubMed1996

Use and safety of a new repetitive transcranial magnetic stimulator.

In order to test a new repetitive transcranial magnetic stimulator, the Dantec MagPro, we administered transcranial magnetic stimulation (TMS) at 1 Hz and 125% of motor threshold for an average of 204 s (until the coil temperature reached 40 degrees C) and 20 Hz stimulation at 100% of motor threshold for 2 s every minute for 10 min, on different days to 10 healthy volunteers. We stimulated 6 scalp positions (primary motor area (M1) and sites 5 cm anterior and posterior on each hemisphere) with an 8-shaped coil. We tested immediate and delayed memory, verbal fluency, prolactin levels and EEG at the beginning of the study and after stimulation on each day. No abnormalities were found. Motor evoked potentials evoked with 1 Hz stimulation diminished progressively in amplitude, and 1 Hz stimulation of M1 caused inhibition lasting at least 1 min in 3 of 4 subjects who were tested with 0.1 Hz stimulation before and after the 1 Hz stimulation period. This did not occur with 20 Hz stimulation. Finger tapping frequency was tested at the beginning of the study and after TMS at each scalp site. Finger tapping rate data from 6 additional subjects who were stimulated in an identical fashion with a different stimulator were also analyzed. There was an increase in tapping rate after TMS which was independent of scalp site. This was most pronounced with 1 Hz stimulation at 125% of threshold and reached statistical significance in the hand contralateral to the stimulation. The results of this study indicate that rTMS with the MagPro stimulator is safe at specific combinations of intensity, frequency and train duration.

Adult↗
PubMed1995

Influence of tobacco marketing and exposure to smokers on adolescent susceptibility to smoking.

BACKGROUND: Today the uptake of smoking is primarily an adolescent pursuit. Awareness of tobacco advertising and promotion is high, and evidence suggests that it plays a role in adolescent smoking uptake. PURPOSE: We evaluated the influence of tobacco advertising and promotion and exposure to smokers on never-smoking adolescents' susceptibility to smoking. METHODS: We used data on 3536 adolescent never smokers (those who had never even puffed on a cigarette) from the 1993 California Tobacco Survey. That survey questioned adolescents about smoking history and inclinations. For this analysis, we defined as susceptible to smoking those never smokers who said on the survey that they could not rule out independently deciding to try a cigarette soon or smoking one offered by a friend. Also for this analysis, we devised two indices: 1) a 5-point index of an individual's receptivity to tobacco advertising as determined by the number of positive responses to five survey items (recognition of advertising messages, having a favorite advertisement, naming a brand he/she might buy, owning a tobacco-related promotional item, and willingness to use a tobacco-related promotional item) and 2) an index classifying an individual's reported exposure to family and peer smoking into one of four levels. Using logistic regression, we assessed the independent importance of our indices in predicting susceptibility to smoking after adjustment for sociodemographic variables, including age, sex, and race/ethnicity, and for perceived school performance. Tests of statistical significance were two-sided. RESULTS: Receptivity to tobacco advertising and exposure to smokers were independently associated with susceptibility to smoking, but the relationship appeared stronger for receptivity to advertising. Adolescents exposed to family members and peers (n = 489) who smoked were 1.89 (95% confidence interval [CI] = 1.30-2.74) times as likely to be susceptible, whereas adolescents who scored 4 or more on the Index of Receptivity to Tobacco Marketing (n = 361) were 3.91 (95% CI = 2.38-6.42) times as likely to be susceptible as those who scored 0. Even adolescents who scored 2 (n = 1090) were 2.03 (95% CI = 1.31-3.15) times as likely to be susceptible. There was no interaction effect between score on the Index of Receptivity to Tobacco Marketing and exposure to smokers. CONCLUSION: Our results support the hypothesis that tobacco marketing may be a stronger current influence in encouraging adolescents to initiate the smoking uptake process than exposure to peer or family smokers or sociodemographic variables including perceived school performance.

Adolescent↗
PubMed1995

Dicarboxylic acid dipeptide neutral endopeptidase inhibitors.

The synthesis of three series of dicarboxylic acid dipeptide neutral endopeptidase 24.11 (NEP) inhibitors is described. In particular, the amino butyramide 21a exhibited potent NEP inhibitory activity (IC50 = 5.0 nM) in vitro and in vivo. Blood levels of 21a were determined using an ex vivo method by measuring plasma inhibitory activity in conscious rats, mongrel dogs, and cynomolgus monkeys. Free drug concentrations were 10-1500 times greater than the inhibitory constant for NEP over the course of a 6 h experiment. A good correlation of free drug concentrations was obtained when comparing values determined by the ex vivo analysis to those calculated from direct HPLC measurements. Plasma atrial natriuretic factor (exogenous) levels were elevated in rats and dogs after oral administration of 19a. Urinary volume and urinary sodium excretion were also potentiated in anesthetized dogs treated with 21a.

Amino Acid Sequence↗
PubMed1995

The predictive value of cytomegalovirus retinitis for cytomegalovirus encephalitis in acquired immunodeficiency syndrome.

Cytomegalovirus (CMV) infection of the brain, optic nerves, and retinas from 47 consecutive autopsies of patients with acquired immunodeficiency syndrome (AIDS) were examined. Immunocytochemistry demonstrated CMV infection in 11 (23%) brains, two (2%) of 94 optic nerves, and 38 (40%) of 94 retinas. Ten (91%) of 11 patients with CMV encephalitis had concurrent retinitis. While 10 (42%) of 24 patients with CMV retinitis had CMV encephalitis, when the retinitis included the peripapillary region, 75% had encephalitis. Usually, the optic nerve parenchyma was not infected histologically despite extensive peripapillary retinitis. The strength of these associations suggests that CMV retinitis defines a group of patients with AIDS at risk for development of CMV encephalitis (relative risk, 9.5), particularly when the retinitis involves the peripapillary region (relative risk, 13). Furthermore, in patients with AIDS without CMV retinitis, central nervous system symptoms are unlikely to be attributable to CMV encephalitis.

AIDS-Related Opportunistic Infections↗
PubMed1995

Can chemicals be loved?--A problem for 2000.

Public perception of the value of chemicals in daily life depends on an often irrational set of conclusions reached on partial or defective information often derived from single issue pressure groups. Benefits are consistently undervalued, clean water and uncontaminated food are taken for granted and changes in the pattern of disease are assumed to have occurred as a result of other kinds of intervention. If we are to ensure a proper evaluation of the place of chemicals in our lives then we will have to persuade opinion formers of the need for rational debate, inform the scientifically literate part of the population about hazard, risk, the difficult concept of safety and the dangers of mistaking association for causation. Changes in science in the field of toxicology give us a more reasonable ground for this debate than has existed in the past and the way in which these can be exploited will be discussed.

Environmental Exposure↗
PubMed1995

Development. The science of damage limitation.

The building of a normal embryo is not accomplished by following a series of complex instructions; rather a number of critical processes enable the cells involved in the process of development to follow pathways which subsequently constrain their growth, mobility and differentiation. There is considerable redundancy in the system, both in terms of mechanisms and permissible outcomes. The way that these processes have become established in evolution gives us a number of insights into how these processes may fail and information from developmental biology informs us about a number of other pathological processes.

Animals↗
PubMed1995

Clinical features and outcome of severe malaria in Gambian children.

The clinical and laboratory features of severe falciparum malaria in 180 Gambian children were studied between 1985 and 1989. Of the 180 children, 118 (66%) presented with seizures, 77 (43%) had cerebral malaria, 35 (20%) had witnessed seizures after admission, 29 (16%) were hypoglycemic, and 27 (15%) died. Respiratory distress was a common harbinger of a fatal outcome. The differences in admission parasite counts in the blood, hematocrit, and opening cerebrospinal pressures for patients who died and survivors were not significant. A multiple logistic regression model identified neurological status (coma, particularly if associated with extensor posturing), stage of parasite development on the peripheral blood film, pulse rate of > 150 or respiratory rate of > 50, hypoglycemia, and hyperlactatemia (plasma lactate level, > 5 mmol/L) as independent indicators of a fatal outcome. Biochemical evidence of hepatic and renal dysfunction was an additional marker of a poor prognosis, but, in contrast to severe malaria in adults, none of these children with severe malaria had acute renal failure.

Adult↗
PubMed1995

Nortriptyline-induced fulminant hepatic failure.

We describe, to our knowledge, the first reported case of nortriptyline-induced fulminant hepatic failure. This tricyclic antidepressant drug was taken by a postmenopausal woman for 64 days before her presentation. The absence of fever, rash, or marked eosinophilia, the predominant zone 3 necrosis with bridging, and the latent period favor a metabolic idiosyncratic reaction. The fatal outcome underscores the importance of recognizing the association and discontinuing the offending agent.

Aged↗
PubMed1995

Growth in utero, adult blood pressure, and arterial compliance.

OBJECTIVES: To examine the relation between disproportionate fetal growth and adult blood pressure and to investigate whether arterial compliance in adult life is related to early development. DESIGN: A follow up study of a group of men and women whose birth weights and other measurements of body size had been recorded at birth. SETTING: Home and outpatient study. SUBJECTS: 337 men and women born in the Jessop Hospital, Sheffield, between 1939 and 1940. MAIN OUTCOME: Adult systolic and diastolic blood pressures and arterial compliance as measured by pulse wave velocity in two arterial segments. RESULTS: Both systolic and diastolic blood pressures were higher in people whose birth weight was low, who were short or who had small abdominal or head circumferences at birth. Systolic blood pressure decreased by 2.7 mm Hg (95% CI 0.8 to 4.6) for each pound (454 g) gain in birth weight and by 3.4 mm Hg (95% CI 1.4 to 5.4) for each inch (2.54 cm) increase in crown-heel length. Diastolic pressure fell by 1.9 mm Hg (95% CI 0.9 to 2.9) for each pound (454 g) gain in birth weight and by 2.4 mm Hg (95% CI 1.4 to 3.5) for each inch (2.54 cm) increase in length. Systolic blood pressure was also higher in individuals whose mother's intercristal pelvic diameter was small or whose mother's blood pressure had been raised during pregnancy but these effects were statistically independent of the effects of low birth weight and other measurements that indicate fetal growth retardation. Arterial compliance was lower in those who had been small at birth. CONCLUSION: Impairment of fetal growth is associated with raised blood pressure in adult life and decreased compliance in the conduit arteries of the trunk and legs.

Arteries↗
PubMed1995

Response of leucine metabolism to hyperinsulinemia under amino acid replacement in experimental hyperthyroidism.

We investigated the responsiveness of protein metabolism to insulin as a mediator of the protein catabolic response to hyperthyroidism in humans. Six healthy volunteers were studied in a postabsorptive state before and after oral intake of thyroid hormones (2 micrograms.kg-1.day-1 L-thyroxine for 6 wk along with 1 microgram.kg-1.day-1 triiodothyronine for the last 2 wk). Insulin was infused at 7.14 nmol.kg-1.min-1 for 140 min under euglycemic and eukalemic clamps. An appropriate amino acid infusion was used to blunt insulin-induced hypoaminoacidemia. Leucine kinetics were assessed using a primed continuous infusion of L-[1-13C]leucine. Hyperthyroidism induced a significant increase (P < 0.05) in leucine endogenous appearance rate (a reflection of proteolysis; 2.15 +/- 0.06 vs. 1.76 +/- 0.03 mumol.kg-1.min-1 in the control state), oxidation (0.54 +/- 0.04 vs. 0.47 +/- 0.07), and nonoxidative disposal (a reflection of protein synthesis; 1.80 +/- 0.06 vs. 1.45 +/- 0.06). Insulin lowered proteolysis. Further hyperthyroidism improved the ability of insulin to inhibit proteolysis, whether considered as an absolute decrease (-0.57 +/- 0.02 vs. -0.45 +/- 0.05 mumol.kg-1.min-1, P < 0.05) or related to insulinemia [1.59 +/- 0.11 vs. 1.01 +/- 0.08 mumol leucine.kg-1.min-1/(nmol insulin/l), P < 0.05]. Insulin also moderately (but significantly P < 0.05) lowered protein synthesis in both control and hyperthyroid states. These changes in insulin action may provide a mechanism to save body protein during hyperthyroidism.

Adult↗
PubMed1995

Population and family studies of three disease-related polymorphic genes in systemic lupus erythematosus.

The contribution to systemic lupus erythematosus (SLE) of three lupus-associated polymorphisms (involving the C4A2 complement component, Humhv3005 and the T cell antigen receptor alpha chain gene) are investigated in 81 individuals from 14 multiplex SLE families, 41 unrelated lupus patients, and 88 unrelated healthy controls. The results show a strong association between C4A deletion and SLE in these families. While the current study confirms the previously reported association between hv3005 deletion and sporadic SLE, the study fails to support this association in familial SLE patients. Moreover, no correlation is detected between the occurrence of hv3005 deletion and C4A null alleles in lupus patients, suggesting that the effects of these genetic polymorphisms on predisposition to lupus are independent. The previously reported lupus-associated T cell receptor (TCR) alpha chain polymorphism is not detected in any of the individuals studied here. The combined data suggest that C4A null alleles predispose strongly to development of lupus, whereas the influence of hv3005 deletion is relatively weak. The results also suggest that contributions of weak susceptibility genes such as hv3005 to disease predisposition may be obscured by the effects of stronger genetic factors and thus need to be examined in patients lacking these factors.

Base Sequence↗
PubMed1995

Characteristics of repeat trauma patients, San Diego County.

Data on 22,312 admissions to the San Diego County Trauma System were used to identify 185 trauma patients admitted repeatedly to trauma units. These patients were compared with the entire group of nonrepeating trauma patients admitted during the 80-month period of the study. In comparison with nonrepeaters, the repeaters were younger, were more often men, were more often Black, and were much more frequently victims of assault. Forty-eight percent of the repeaters were injured by the same general mechanism on both admissions.

California↗
PubMed1995

Renal ultrasonography as a tool for detecting dynamic changes in blood pressure.

Renal ultrasonography has been used to assess renal blood flow under pathological conditions. We attempted to determine if sonographically derived renal resistive index measurements would be affected by subtle changes in flow as a consequence of transiently induced mild increases in blood pressure in persons with normal renal functioning. Nine subjects free of structural renal disease were studied with duplex Doppler ultrasonography. Main renal artery resistive indices were determined under resting baseline conditions and in response to graded infusions of phenylephrine sufficient to increase blood pressure by approximately 13/5 mm Hg. Change in blood pressure correlated with the change in main renal artery resistive index (r = 0.254, P < 0.05). Thus, the resistive index varies in association with transient increases in blood pressure and may reflect concurrent alterations in distal resistance under physiologic conditions.

Blood Pressure↗
PubMed1995

A rapid indirect method to determine the plasma concentrations of neutral endopeptidase inhibitors.

The selection of therapeutic agents for clinical development is principally based upon pharmacodynamic and pharmacokinetic criteria. Although many compounds are routinely tested in pharmacologic assays, direct pharmacokinetic assessment is difficult and not applicable to a large number of agents. Therefore, we have developed a rapid indirect method based on enzyme inhibition for determining the unbound concentration of NEP 24.11 inhibitors in rat plasma. In the present study, drug levels of compounds from three different classes of NEP 24.11 inhibitors: mercaptoalkyl, carboxyalkyl and aminophosphonates were compared. Studies were carried out in conscious, unrestrained rats. Arterial blood samples were obtained 10, 30, 60, 120, and 240 min after drug administration at 10 mg/kg i.v. or 30 mg/kg p.o. The blood was collected in EDTA and plasma prepared immediately. Protein bound NEP inhibitor was separated from plasma by centrifugation through an ultrafiltration membrane. Following acidification and serial dilution, the concentration of unbound inhibitor was determined in the plasma ultrafiltrate using the in vitro assay for NEP 24.11 inhibition. The results of this study indicated that the mercaptoalkyl inhibitor thiorphan was cleared rapidly from plasma, whereas, the plasma concentrations of the carboxyalkyl inhibitor CGS 23880A (UK-69,578), and the plasma concentrations of the aminophosphonate, CGS 24128, were maintained at high levels for at least 4 hours. Furthermore, the ratio of the NEP inhibitor concentration/IC50 value correlated well with the pharmacologic activity of these compounds.

Animals↗