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Biomedical subjects

A Williams

Publications and source records attributed to A Williams.

At least 217 records · Page 12Linked to original sources
PubMed1999

Attaining higher goals in HIV treatment: the central importance of adherence.

In recent years, advances in HIV therapeutics have changed the nature of HIV/AIDS disease, so that it has now assumed some of the characteristics of a 'chronic' disease. Several factors have, however, qualified these advances. Social, economic, and clinical variables have confounded universal therapeutic success. Access to the highly active antiretroviral therapy is limited among marginalized populations, such as the homeless, or absent in many nations that have poor resources. In addition, study populations are often not fully representative of those actually cared for in clinical practice, who may respond differently to the study medications. Moreover, physiologic differences between patients may alter drug plasma levels, resulting in varying efficacy levels in different patients. Finally, and crucial among determinants of effective therapy, is a patient's level of adherence to the antiretroviral regimen. The magnitude of 'error-prone' viral replication makes resistance to antiretroviral agents invariable. In the presence of partially suppressive therapy, viral replication will select for viral variants with resistance mutations. Therefore, potent and continuous suppressive therapy for the duration of viral replicative capability is necessary for therapy to be effective. Factors that have an impact on adherence include characteristics of the treatment regimen, of patients and clinicians, and of the clinical setting. Successful adherence to therapeutic regimens is the responsibility of clinicians as well as patients. Many patient- and clinician-focused strategies and interventions that can improve adherence exist. The simplification of current antiviral regimens, without the loss of potency, is essential to achieving the goal of complete adherence. Maximizing the long-term benefit of highly active antiretroviral therapy requires knowledge of the technical and biologic aspects of HIV therapeutics, but necessitates an understanding of the behavioral aspects of therapeutics as well.

Anti-HIV Agents↗
PubMed1999

Effects of antidepressants and benzodiazepine-type anxiolytic agents on hepatic porphyrin accumulation in primary cultures of chick embryo liver cells.

Patients with any of the acute porphyrias may suffer from acute attacks. If these patients are treated with certain drugs, such as barbiturates, the likelihood of developing an attack is increased. Patients treated with antidepressants or benzodiazepine-type anxiolytics also could be placed at increased risk of developing porphyric attacks because little is known about the potential for some of these drugs to induce attacks. Primary cultures of chick embryo liver cells were used to study the effects of selected antidepressants and anxiolytics on porphyrin accumulation. Cells were treated with desferrioxamine (to partially block heme synthesis, simulating conditions encountered in porphyric patients) and increasing concentrations (3.16-1000 microM) of the evaluated drugs. Twenty hours later, porphyrin accumulation was measured. The drugs included four antidepressants and five benzodiazepine-type anxiolytics. The antidepressants bupropion and nefazodone significantly increased porphyrin accumulation when given with desferrioxamine, whereas neither fluoxetine nor paroxetine increased porphyrin accumulation. The benzodiazepine-type anxiolytic agents oxazepam, lorazepam, diazepam, triazolam, and midazolam all significantly increased porphyrin accumulation when given with desferrioxamine. Dose-response studies showed that diazepam, midazolam, and triazolam produced significant increases even at the lowest concentration tested (3.16 microM), whereas lorazepam and oxazepam required higher concentrations (>/=10 microM). These studies suggest that patients with acute porphyrias may be at greater risk for developing porphyric attacks when treated with bupropion or nefazodone compared with fluoxetine or paroxetine, and that the evaluated benzodiazepine derivatives should be administered with caution. Among the latter, low doses of lorazepam and oxazepam may be safer than those of diazepam, midazolam, and triazolam.

Animals↗
PubMed1999

A review of senior nurses' roles in an acute trust.

The relationship between the managerial and clinical roles of senior nurses should be given more attention. Senior nurses believe some colleagues do not understand their role and feel they need more support.

Adult↗
PubMed1998

Adrenergic receptors in premenstrual dysphoric disorder: I. Platelet alpha 2 receptors: Gi protein coupling, phase of menstrual cycle, and prediction of luteal phase symptom severity.

BACKGROUND: Abnormal alpha 2-adrenergic receptor (AR) function is implicated in anxiety and depressive disorders. Premenstrual dysphoric disorder (PMDD) is characterized by anxiety and depressive symptoms, which may be associated with changes in alpha 2AR function. Previous studies on alpha 2AR function during phases of the menstrual cycle in controls and PMDD patients are inconsistent. METHODS: alpha 2AR function was examined in 16 PMDD patients and 15 controls during the follicular phase, and in 10 PMDD patients during late luteal phase. Antagonist-measured maximum binding capacity, agonist-measured receptor density in high- and low-conformational states, and agonist affinity to both states were measured. Coupling efficiency to Gi protein was estimated. RESULTS: There were no significant differences in coupling efficiency. PMDD patients had significantly low antagonist affinity; there were no differences in other binding parameters. There were no changes in alpha 2AR binding parameters between phases of menstrual cycle in PMDD women. alpha 2AR density and symptom severity were inversely related during the follicular phase in controls and patients. During luteal phase, alpha 2AR density correlated positively with symptom severity in patients. High follicular alpha 2AR density predicted more severe luteal symptoms in PMDD patients. CONCLUSIONS: These findings are discussed in view of the molecular biology of alpha 2AR, and their role in PMDD, anxiety, and depressive disorders.

Adult↗
PubMed1998

Lemierre syndrome: a complication of acute pharyngitis.

Lemierre syndrome, otherwise known as postanginal sepsis or necrobacillosis, is an illness that originates as an acute pharyngitis or tonsillitis which progresses to sepsis, usually fusobacterial, due to suppurative thrombophlebitis of the internal jugular vein. Septic thromboemboli then seed various organs, resulting in multiple organ system pathology, most commonly affecting pulmonary and hepatic systems and joints. Although rare in the age of antibiotics, this disease typically affects previously healthy adolescents with varied clinical manifestations depending upon organ system involvement (A. Lemierre, Lancet March (1936) 701-703; J. Barker, H.T. Winer-Muram, S. Grey, Southern Med. J. 89 (1996) 1021-1023). Prompt diagnosis based on clinical presentation, radiologic findings, particularly CT scanning with contrast and a high index of suspicion, is necessary in order to institute often life saving therapy (J. Barker, H.T. Winer-Muram, S. Grey, Southern Med. J. 89 (1996) 1021-1023). We will present two cases of Lemierre syndrome, review it's clinical presentation, anatomic considerations, particularly it's relationship to the parapharyngeal space, radiographic findings, potential life threatening complications and finally, a unique approach to therapy.

Adolescent↗
PubMed1998

Supernumerary nostril: a rare congenital deformity.

Duplication anomalies of the nose include polyhinia (double nose) and supernumerary nostril (assessory nostril). These are rare congenital nasal deformities resulting from aberrant embryological development. Differential diagnoses include glioma, encephalocele, nasal dermoid, nasolacrimal duct duplication, mid facial cleft and proboscis lateralis (K. Nakamura, T. Onizuka. Plast. Reconstr. Surg. 80 (3) (1987) 436-441). Our review of the English language literature revealed eight reported cases of duplication anomalies of the nose. Four of these were cases of polyrhinia (double nose). Of the cases remaining, one patient had a supernumerary nostril in association with a cleft lip, leaving only three reported cases of an isolated supernumerary nostril. We present a newborn infant with an isolated right supernumerary nostril. MRI, CT and photographic documentation are provided. Pertinent embryology, anatomy and a thorough review of the literature are included.

Humans↗
PubMed1998

Adrenergic receptors in premenstrual dysphoric disorder. II. Neutrophil beta2-adrenergic receptors: Gs protein coupling, phase of menstrual cycle and prediction of luteal phase symptom severity.

Abnormal beta2-adrenergic receptor coupling to Gs protein is implicated in depressive disorders. Steroid hormones and antidepressants modulate beta-adrenergic receptor coupling, which may relate to the therapeutic efficacy of antidepressants. We examined beta2-adrenergic receptors in 18 patients with premenstrual dysphoric disorder (PMDD), in 15 control subjects during the follicular phase and in 12 patients during late luteal phase. Antagonist-measured receptor density, agonist-measured receptor density in the high- and low-conformational states and agonist affinity to both states were measured. Coupling indices to Gs protein were determined from agonist-displacement experiments. Follicular beta2-adrenergic receptor density was higher in patients than in control subjects, with a trend for higher receptor density in the high-conformational state. The phase of menstrual cycle had no effect on beta2-adrenergic receptor regulation in PMDD. Exploratory correlations showed that the K(L)/K(H) ratio was related to anxiety ratings in control subjects and %R(H) was correlated with symptom severity in patients. In patients, follicular beta2-adrenergic receptor binding measures were correlated with luteal symptom severity. These findings suggest abnormal beta2-adrenergic receptor regulation in PMDD. Further exploration of the role of beta-adrenergic receptor kinase, sex steroid hormones and antidepressants on beta-adrenergic receptor regulation in PMDD is warranted.

Adult↗
PubMed1998

Trust mergers. Turning threats into opportunities.

A survey of senior health staff in Wales shows widespread scepticism about the benefits of trust mergers. Trust mergers in Wales may fail because those responsible for making them work do not believe they can succeed. Benefits will only be realised if the post-merger process is addressed in such a way as to gain staff commitment.

Attitude of Health Personnel↗
PubMed1998

Siliceous tablets in the larval shells of apatitic discinid brachiopods

The marine bivalved Brachiopoda are abundant throughout the geological record and have apatitic (CaPO4-rich) or calcitic (CaCO3-rich) shells. Vesicles covering the larval valves of living apatitic-shelled discinids contain tablets of silica. The tablets are cemented into close-packed mosaics by spherular apatite in glycosaminoglycans. They are usually lost as vesicles degrade but leave imprints on the underlying apatitic shell. Similar imprints ornament larval surfaces of some of the earliest Paleozoic apatitic-shelled brachiopods and may also be indicators of siliceous biomineralization.

Journal Article↗
PubMed1998

Variations in population health status: results from a United Kingdom national questionnaire survey.

OBJECTIVE: To measure the health of a representative sample of the population of the United Kingdom by using the EuroQoL EQ-5D questionnaire. DESIGN: Stratified random sample representative of the general population aged 18 and over and living in the community. SETTING: United Kingdom. SUBJECTS: 3395 people resident in the United Kingdom. MAIN OUTCOME MEASURES: Average values for mobility, self care, usual activities, pain or discomfort, and anxiety or depression. RESULTS: One in three respondents reported problems with pain or discomfort. There were differences in the perception of health according to the respondent's age, social class, education, housing tenure, economic position, and smoking behaviour. CONCLUSIONS: The EQ-5D questionnaire is a practical way of measuring the health of a population and of detecting differences in subgroups of the population.

Adolescent↗
PubMed1998

Primeval health economics in Britain: a personal retrospect of the pre-HESG (Health Economists' Study Group) period.

There is a danger that the history of health economics in Britain comes to be regarded as roughly co-terminous with the history of the Health Economists' Study Group (HESG). As one of the founders of that Group, I would take some pride from that, if it were true. But it is not. Just as primitive human societies existed before recorded history, so there was primeval health economics in Britain prior to 1972. There is probably more of this primeval health economics than even I know about, but as one of the ancient relics of that period I have been offered the opportunity to reminisce about what I saw during those dark ages! When one reaches the advanced age of 70, there is no escaping the fact that your past is bound to be more extensive (and probably more enjoyable) than your future, which is why the old enjoy looking back more than they enjoy looking forward! I am no exception. Hence this essay, which may either be seen as a rather self-indulgent bout of nostalgia concerning the early days of health economics in Britain, or as an archaeological enterprise, exhibiting, for all to wonder at, the treasures to be found at carefully selected ancient (i.e., pre-HESG) sites in Britain. Either way, my purpose is to suggest that most of the fundamental issues with which health economists have grappled in the last 25 years had already been identified and addressed in a careful way during the decade preceding the formation of the HESG.

Aged↗