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Biomedical subjects

K Gee

Publications and source records attributed to K Gee.

14 recordsLinked to original sources
PubMed1995

Caged cyclic ADP-ribose. Synthesis and use.

Cyclic ADP-ribose (cADPR) is a recently discovered cyclic nucleotide with Ca2+ mobilizing activity. Caged cADPR was synthesized by reacting cADPR with 2-nitrophenethyldiazoethane. Elemental analyses, 1H NMR, and extinction coefficient measurements indicate that the product contains only one caging group. Anion exchange high pressure liquid chromatography separated caged cADPR into two forms, which most likely represent isomers. Both forms could be uncaged with equal efficiency by UV exposure to regenerate cADPR. Photolysis of caged cADPR was accomplished effectively with a spectrofluorimeter. The efficiency of uncaging depended on wavelength with UV light shorter than about 320 nm being the most effective. Caged cADPR was biologically inactive and could induce Ca2+ release from sea urchin egg homogenates only after photolysis. Specificity of the Ca2+ release was shown by inhibition by 8-amino-cADPR, a specific antagonist of cADPR. To demonstrate its utility in live cells, caged cADPR was microinjected into sea urchin eggs. Photolysis using a mercury light source effectively regenerated cADPR and resulted in Ca2+ mobilization and activation of cortical exocytosis in the eggs.

ADP-ribosyl Cyclase↗
PubMed1995

Use of integrated, general education, and community settings as primary contexts for skill instruction for students with severe, multiple disabilities.

Four students with severe, multiple disabilities learned to use four to five new skills at critical moments within age-appropriate activities. Instruction was provided only at moments critical to the continuation of the activities when natural cues and consequences delineated the need for the target behaviors. This method of intervention was combined with a more traditional package of antecedent prompt-fade procedures and, in a few instances, time delay. The purpose of the study was to analyze the effects of instruction given only at natural critical moments on the acquisition of basic sensory, motor, social, and communication behaviors. A multiple baseline design across skills within separate activities for four participants was employed. Fifteen of 17 skills were acquired to criterion. In addition, "learning to learn" effects occurred within each activity as instruction of new target behaviors was introduced. The outcomes are important for the participant population because they document the effect of integrated educational models for teaching the most basic skills. Discussion of the motivation provided by activity routines in general education and community settings, as well as interpretation of data when participants have the most severe disabilities, is presented.

Behavior Therapy↗
PubMed1994

Ammonia hypersensitivity of slugger mutants of D. discoideum.

The weak base ammonia inhibits aggregation and culmination of wild-type amoebae of Dictyostelium discoideum. Here we have examined its effect on a series of 'slugger' mutants previously assigned to 10 complementation groups, and so-called because they remain as slugs for extended periods. We show that the mutants accumulate normal levels of ammonia and hence may be abnormally susceptible to the ammonia they produce. In agreement with this we find that representatives of the slugger complementation groups are hypersensitive to ammonia inhibition at three clearly recognisable morphological stages of development: aggregation, tip formation and culmination. This finding suggests that a common ammonia-sensitive process underlies each of these developmental events.

Amines↗
PubMed1992

Prevalence of anaemia and iron deficiency at different levels of urbanization in Vanuatu.

Mean haemoglobin and plasma iron levels and prevalences of anaemia and iron deficiency were determined in three population samples of Vanuatuans aged 20 or more years as part of a noncommunicable diseases survey in 1985. The three samples were drawn from separate urban, semirural and rural populations. Age-adjusted mean haemoglobin levels were highest in the urban sample and lowest in the rural sample, and plasma iron levels were highest in the urban sample and lowest in the semirural sample. Mean values in each location were generally higher in male subjects than in nonpregnant female subjects. The overall prevalence of anaemia was 10.1% in nonpregnant female subjects and 5.3% in male subjects by World Health Organization (WHO) definitions. These prevalences are lower than those reported for most other developing countries, including some Pacific island nations. Iron deficiency was more prevalent in females than in males (females 17.2%; males 5.0%). Approximately 40% of anaemic subjects were also iron deficient, and there was a significant positive correlation of plasma iron levels with haemoglobin concentration. This suggests that haemoglobinopathies may not be a major cause of anaemia as previously reported. Although most anaemic subjects (88%) had only mild anaemia, in view of the physical lifestyle of rural and semirural Vanuatuans it would be important to optimize haemoglobin levels in these populations.

Adult↗
PubMed1991

Prevalence of diabetes, hypertension and obesity at different levels of urbanisation in Vanuatu.

OBJECTIVE: To determine the prevalence of non-communicable disease, specifically hypertension, diabetes and obesity, amongst populations at different levels of urbanisation in Vanuatu, and to relate the frequency of these conditions to the modernisation of way of life. DESIGN: A cross-sectional population-based comparative study of indicative cluster samples. SETTING: Republic of Vanuatu (south-west Pacific). A relatively undeveloped malarious island country. PARTICIPANTS: Adult (aged greater than or equal to 20 years) Melanesian ni-Vanuatu of both sexes. An occupation-based (civil servants) urban sample (n = 623) and area-based semi-rural (n = 349) and rural (n = 397) samples were employed. Response rates were 78%-92%. INTERVENTIONS: Cases detected were referred for assessment and treatment by local medical staff. MAIN OUTCOME MEASURES: Body mass index, triceps skinfold thickness, blood pressure, plasma glucose (fasting and 2 hours after 75 g glucose), plasma cholesterol and triglyceride levels. RESULTS: Modernity scores confirmed that the three locations represented different levels of acculturation. Prevalences of non-communicable disease were relatively low compared to other Pacific Island communities and industrialised countries. These conditions were nevertheless more common in the urban sample and least common in the rural sample. Non-communicable disease correlated positively with modernity scores and negatively with physical activity scores. Obesity correlated with blood pressure in the urban sample, and there was indirect evidence (urine sodium concentration) of higher salt intake with modernisation. Mean plasma cholesterol levels were lowest in the rural group. CONCLUSIONS: Prevalences of non-communicable disease are relatively low in Vanuatu, although rural-urban differentials are present, and likely to increase with continued development. The evidence presented is consistent with non-communicable disease being related to the modernisation of way of life; specifically: decreased exercise, obesity, and dietary change. Preventive activities should commence now.

Adult↗
PubMed1983

Conformationally constrained cyclic enkephalin analogs with pronounced delta opioid receptor agonist selectivity.

The enkephalin analogs, [D-Pen2,L-Cys5]- and [D-Pen2,D-Cys5]-enkephalin are cyclic compounds, conformationally constrained by virtue of their 14-membered, disulfide containing rings and by the rigidizing effect of the beta, beta dimethyl substituents of the penicillamine side chain. The analogs exhibit profound delta receptor specificity as assessed by their relative potencies in the guinea pig ileum (GPI) and mouse vas deferens (MVD) assays, exhibiting, respectively, 666 and 215 times higher potency in the latter assay system. By contrast, the receptor selectivities measured in rat brain binding assays in the absence of sodium were much more modest, the cyclic analogs being, respectively, 15.2 and 6.0 times more effective at displacing [3H] [D-Ala2,D-Leu5]enkephalin than [3H]naloxone. However, for binding assays performed in the presence of a sodium concentration equivalent to that used in the GPI and MVD assays, these binding selectivities increased to 167 and 49, respectively.

Animals↗
PubMed1983

Cyclic penicillamine containing enkephalin analogs display profound delta receptor selectivities.

The cyclic, penicillamine(beta, beta dimethylcysteine)-containing enkephalin analogs, [D-Cys2, L-Pen5]-and [D-Cys2, D-Pen5]enkephalin and the corresponding bis-penicillamine analogs, [D-Pen2, L-Pen5]-and [D-Pen2, D-Pen5]enkephalin were synthesized and evaluated for opioid activity in the guinea pig ileum (GPI) and mouse vas deferens (MVD) bioassays and in rat brain and neuroblastoma-glioma cell membrane binding assays. These analogs all displayed delta receptor selectivity as assessed by IC50(GPI)/IC50(MVD) ratios and by their relative potencies for displacing [3H]naloxone (NAL) vs. [3H] [D-Ala2, D-Leu5]enkephalin (DADLE) from rat brain membrane preparations. For [D-Pen2, L-Pen5]- and [D-Pen2, D-Pen5]enkephalin the observed IC50(GPI)/IC50 (MVD) ratios (1088 and 3164) and IC50NAL/IC50DADLE ratios (371 and 175) represent a vast improvement over previously reported delta receptor selective ligands.

Animals↗
PubMed1983

Bis-penicillamine enkephalins possess highly improved specificity toward delta opioid receptors.

The conformationally restricted, cyclic, disulfide-containing, enkephalin analogs [2-D-penicillamine, 5-L-penicillamine]enkephalin [(D-Pen2,L-Pen5]enkephalin) and [2-D-penicillamine, 5-D-penicillamine]enkephalin [(D-Pen2,D-Pen5]enkephalin) were synthesized by solid-phase methods. Selectivities of these analogs for a single class of opioid receptor were investigated by examining relative potencies in the mouse vas deferens assay, in which the functional receptor is the delta receptor, versus the guinea pig ileum assay, in which the mu receptor is the functional receptor, and by determining their relative abilities to displace the prototypical delta receptor ligand [D-Ala2, D-Leu5]enkephalin and the prototypical mu receptor ligand naloxone from rat brain membrane preparations. Based on these comparisons [D-Pen2,L-Pen5]- and [D-Pen2,D-Pen5]enkephalin exhibited delta receptor selectivities of 1,088 and 3,164, respectively, in the bioassays, and 371 and 175, respectively, in the binding assays. Compared with the previously reported delta receptor selective analogs, [D-Ala2,D-Leu5]enkephalin, [D-Ser2,Leu5,Thr6]enkephalin, and [D-Thr2,Leu5,Thr6]enkephalin, the bis-Pen-containing analogs provide an order of magnitude increase in delta receptor selectivity.

Animals↗
PubMedDate not supplied

Cardiopulmonary resuscitation: basic life support skills: 1.

Basic life support (BLS) is potentially life-saving and unnecessary delays in starting BLS must be avoided. Sudden cardiac death occurs within 1 hour of symptoms in 40% of patients, and in 60% of young/middle-aged patients. BLS can support the casualty and save lives. Bystanders, including nurse aiders, should summon professional help before commencing BLS. Although technical expertise and equipment are necessary in specific situations, BLS 'buys time' while waiting for the equipment to arrive. Seventy per cent of cardiac arrests occur in the home and as BLS skills are often the only skills immediately available, their acquisition is essential.

Clinical Competence↗
PubMedDate not supplied

Cardiopulmonary resuscitation: basic life support skills: 2.

In the first of this two-part series, the reasons why nurses were not prepared to take action when faced with an emergency were examined. This article takes a step-by-step look at cardiopulmonary resuscitation as specified by the European Resuscitation Council.

Heart Arrest↗
PubMedDate not supplied

Competency through being: the enemy within?

Nurses are taking on more medical tasks but is this appropriate? If so, does this advance nursing practice? The issue hinges on the nurse's competency which is central to professional nursing practice.

Clinical Competence↗