Acanthamoeba rRNA transcription involves the binding of a transcription initiation factor (TIF) to the core promoter of rDNA to form the preinitiation complex. This complex is formed in the absence of RNA polymerase I, and persists for multiple rounds of initiation. Polymerase I next binds to form the initiation complex. This binding is DNA sequence-independent, and is directed by protein-protein contacts with TIF. DNA melting occurs in a separate step. In contrast to most prokaryotic transcription, melting occurs only following nucleotide addition and beta-gamma hydrolysis of ATP is not required as for polymerase II. Growth-dependent regulation of rRNA transcription is accomplished by modification of RNA polymerase I. The inactive form of polymerase (PolE) is unable to bind to the promoter and has altered heat stability. PolE is still active in elongation; thus, the modification affects the polymerase site involved in TIF contact. Modification of a polymerases I and III common subunit has been detected leading to the suggestion that transcription of stable RNAs of the ribosome might be co-regulated by this mechanism.

Acanthamoeba↗

PubMedDate not supplied

Toward assessing family outcomes of service delivery: validation of a family quality of life survey.

BACKGROUND: The concept of family quality of life (QoL) has emerged as an important outcome of service delivery for individuals with disabilities and their families. The present study describes the process of developing a tool to measure family QoL. METHODS AND RESULTS: A total of 1197 respondents participated in a national field test. Through factor analysis, the survey was refined in several ways: (1) the preliminary 10-domain structure was reduced to a five-domain structure; (2) a total of 41 items were selected for the revised survey; and (3) wordings were clarified. CONCLUSIONS: The implications for future research and practice are discussed.

Adolescent↗

PubMedDate not supplied

Asthma education: creating a partnership.

This article advances the theory that the key to creating an effective partnership is teaching asthma patients what to self-treat, how to self-treat, and when to consult a clinician. The five comanaging rules that the health educator is encouraged to emphasize with the adult asthma patient are: know your own unique asthma symptoms and triggers; keep written records; see appropriate specialists; know your medicines and follow your action plan; and accept no treatment you do not understand. Current research shows asthma to be a chronic inflammatory disorder of the airways. In susceptible individuals, this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly at night and in the early morning. The stepwise approach to asthma therapy divides asthma into several levels of severity. However, patients at any level of severity can have mild, moderate, or severe exacerbations. Asthma triggers; how to use a metered dose inhaler (MDI), a dry powder inhaler (DPI), and a peak flow meter; and how to follow an asthma action plan are thoroughly covered. The last section of the article deals at length with the indications for and actions of long-term-control medications, used to achieve and maintain control of persistent asthma, and quick-relief medications, used to treat symptoms and exacerbations.

Adrenergic beta-Agonists↗

PubMedDate not supplied

Implications of issues in typographical design for readability and reading satisfaction in an aging population.

The issues in typographical design that influence readability in an aging population are explored. The traditional response to age-related changes in vision has been "bigger is better," but we explore other major variables and vocabulary associated with page layout and design, including type classification and readability, justification, traditional rules of page composition, and issues of word forms versus character strategies. Other research areas that should be explored are also considered.

Aged↗

PubMedDate not supplied

Hepatitis due to herpes simplex virus in a nonpregnant patient: treatment with acyclovir.

A previously healthy 19-year-old nonpregnant woman had disseminated infection with herpes simplex virus. The disseminated disease was accompanied by hepatitis. The patient was treated with parenteral acyclovir (5 mg/kg) given every 8 hr. The patient's symptoms resolved after three days of therapy. A review of five similar cases that were observed in healthy nonpregnant and nonimmunosuppressed individuals showed that all five patients died. Thus, rapid diagnosis of this potentially fatal condition is important, and the possible use of acyclovir for such cases should be considered.

Acyclovir↗

PubMedDate not supplied

Coronary and peripheral vascular resistance in the anaesthetized diabetic sheep.

To determine whether vascular resistance was altered in diabetes, the vascular resistance in both the peripheral arterial bed and the circumflex coronary artery was compared in six normal and five diabetic adult sheep, under pentobarbitone anaesthesia. Diabetes induced by alloxan significantly increased blood glucose (15.6 mmol/l, s.e.m. = 2.8, vs 5.5 mmol/l, s.e.m. = 0.6; P greater than 0.001) compared with controls. Systolic blood pressure was lower in diabetics (92 mmHg, s.e.m. = 12, vs 123 mmHg, s.e.m. = 5; P less than 0.025) as was diastolic blood pressure (73 mmHg, s.e.m. = 15, vs 104 mmHg, s.e.m. = 4; P greater than 0.05). Basal peripheral resistance was lower in diabetics than controls (36.0 mmHg.min/l, s.e.m. = 7.9, vs 42.3 mmHg.min/l, s.e.m. = 2.8), but not significantly so. Methoxamine markedly increased peripheral vascular resistance in both groups, but did not change coronary vascular resistance, due to autoregulation. The dose-response curves of peripheral or coronary arteries to methoxamine showed no significant difference between diabetic and control sheep. Dose-response curves for isoprenaline and noradrenaline infusion suggested there may be altered beta-receptor sensitivity in diabetes. In conclusion, there are marked differences in the vascular beds of diabetic and normal sheep under basal conditions. In contrast to previous studies, alpha-adrenoceptors are not different in diabetics, but further studies in unanaesthetized animals are indicated, as beta-receptor sensitivity may be altered in diabetes.

Acetylcholine↗

PubMedDate not supplied

Arrangement of vestibular nerve fibers in the semicircular canal crista of the chinchilla.

The topographic arrangement of vestibular nerve fibers innervating semicircular canal cristae of the chinchilla was studied using computer-aided video-microscopy and three-dimensional reconstruction. At the level 20 microns proximal to the base of the crista, bundles consisting of 30-50 nerve fibers each were identified. Nerve fibers in bundles were classified into seven categories depending on the diameter. We confirmed that large nerve fibers were more frequently found in the central bundles and small nerve fibers were more frequently found in the peripheral bundles. The central bundle might function as a physiological unit coding various types of head movements, whereas the peripheral bundle might contribute more to the detection of slow and long-lasting movements giving rise to tonus and posture changes. The canalicular nerve may code rotational acceleration of the head via function- and locus-specific nerve fiber bundles.

Animals↗

PubMedDate not supplied

The value of saline salpingosonography as a surrogate test of tubal patency in low-resource settings.

BACKGROUND: Tubal factor, which accounts for 15-30% of infertility in all women, is common in developing countries with high rates of pelvic inflammatory disease but limited resources. It is possible to outline the fallopian tubes by injecting isotonic saline transcervically during transvaginal ultrasound scanning of the pelvis, and both color flow Doppler and 3-dimensional scanning modes have been employed to improve visualization of the tubes, with varying success. METHOD: We investigated the value of saline salpingosonography (SSG), using 2-dimensional transvaginal ultrasound scanning, as a screening test of tubal patency in 113 women by comparing SSG findings to those at HSG or laparoscopy. RESULTS: The findings at SSG correlated well with the results of HSG or laparoscopy, with an overall concordance of 82.5%. SSG was more accurate at diagnosing patent tubes than blocked tubes and was well tolerated. The results are, however, unreliable when it is difficult to inject the saline and when the patient experiences severe pain during the procedure. CONCLUSION: SSG is a useful screening tool for investigating infertility, particularly in low-resource settings.

Adult↗

PubMedDate not supplied

[A neuroanatomical study of the vestibular efferent system, III: the origin and pathway of the axons].

We have studied the vestibular efferent fibers pathway, after scratching the peripheral vestibular receptors and horseradish peroxidase injection, and TMB or DAB processing. We have proved the existence of a differentiated bundle in the main vestibular pathway, this bundle crosses the areas where the efferent somas have been situated, some of this fibers have been seen crossing the midline. It has not been possible to connect the efferent somas with the fibers.

Animals↗