Biomedical subjects

S R Maxwell

Publications and source records attributed to S R Maxwell.

43 records · Page 3Linked to original sources

PubMed1991

The penetration of cefpirome into the potential sites of pulmonary infection.

The concentrations of cefpirome, a new semi-synthetic cephalosporin, in the bronchial mucosa and serum were assessed after a single 1 g intravenous dose in 37 patients. Bronchoalveolar lavage allowed epithelial lining fluid (ELF) concentrations to be measured in eight subjects. The mean concentration for serum was 34.5 mg/L (S.E.M. 3.3), for bronchial mucosa 19.3 mg/kg (S.E.M. 1.9) and for ELF 7.2 mg/L (S.E.M. 1.1). The progressive reduction in cefpirome concentration in serum compared to that in bronchial mucosa and ELF is consistent with the permeability characteristics of beta-lactam antimicrobials and the barriers to movement of antimicrobial agents present in the lung.

Adult↗

PubMed1991

Controlled release metoprolol. Clinical pharmacokinetic and therapeutic implications.

Metoprolol is a relatively beta 1-selective beta-blocker used extensively to treat hypertension and angina and as a prophylaxis after myocardial infarction. Conventional formulations are usually administered twice daily and the drug has a tendency to lose its selectivity of action at higher plasma concentrations. Two controlled release formulations, metoprolol CR and metoprolol 'Oros', have made it possible to achieve sustained beta 1-blockade over an entire 24h period and to minimise the loss of selectivity associated with higher plasma concentrations. The CR formulation has been extensively investigated and is the major subject of this review. The 'Oros' formulation is pharmaceutically different from the CR, yet both produce similar plasma concentration profiles and comparable beta 1-blocking effects. The availability of these preparations occurs at a time when increasingly persuasive data are becoming available on the cardioprotective or coronary preventive action of metoprolol.

Biological Availability↗

PubMed1985

Oral rehydration of infants in a large urban U.S. medical center.

A prospective randomized study of 100 well-nourished infants with acute gastroenteritis resulting in dehydration and acidosis was carried out at the Jackson Memorial Hospital, Miami from 1981 to 1983. Patients were randomly assigned to receive either standard intravenous therapy or oral rehydration. Infants in the latter group first received solution A containing 75 mEq/L sodium, 30 mEq/L potassium, 75 mEq/L chloride [corrected], 30 mEq/L bicarbonate, and 2 gm/dL glucose [corrected]. After ad libitum feeding for six hours, solution B containing 50 mEq/L sodium, 30 mEq/L potassium, 50 mEq/L chlorine, 30 mEq/L bicarbonate, and 3 gm/dL [corrected] glucose was given. With three exceptions (6%), oral rehydration was comparable to the intravenous regimen in clinical estimates of improvement, although the oral group had more stools in the first day. The oral group had faster correction of acidosis and a sustained rise in serum potassium concentration, whereas in the intravenous group the potassium concentration showed first a drop with a later increase, but levels were at all times below those in the oral group. Although potassium was given from the beginning of oral rehydration, and at a higher concentration than recommended by the World Health Organization, no hyperkalemia occurred. We concluded that oral therapy is safe, less expensive for patients, and more convenient for the medical and nursing staffs.

Blood Glucose↗

PubMed1978

Radiological evaluation of the cardiac apex in Jamaican children.

The position of the clinical apex beat projected on chest radiographs was compared to different points on the cardiac outline which have been regarded as the radiological apex. Good correlation was found between the clinical apex and the most lateral point of the left cardiac border, but not with the cardiophrenic angle or the lower end of the long diameter of the heart. The mid-clavicular line cannot be used to define the upper limit of the normal sized heart on radiographs as in clinical practice, because in many of the subjects the heart extended outside the mid-clavicular line.

Child↗

PubMed1978

Position of the apex beat in childhood.

The position of the apex beat in relation to the midclavicular and nipples lines and the intercostal spaces was studied in 353 healthy Jamaican children from birth to 10 years. The traditional use of the midclavicular line as a reference point in relation to the apex beat is not an accurate index of normal heart size at all ages. For this purpose actual measurement of the apex beat, which ranges between 2.8 and and 5.4 cm from the midline, should be made. However, for a rough estimate of normal cardiac size the midclavicular line may be used. In contrast, the nipple line lies outside the apex beat at all ages; it should not be used in the clinical evaluation of normal cardiac size. From birth to age 3 years the apex beat is located in the 4th intercostal space and with increasing age gradually moves into the 5th space in most children.

Anthropometry↗

PubMedDate not supplied

Developmental outcomes in very low birth weight infants: a six-year study.

Advances in neonatal care have led to survival of more Very Low Birth Weight (VLBW) infants weighing < 1,500 grams with growing concerns about neuro-developmental outcomes. To identify relationships between outcomes and birth weight, we evaluated 213 VLBW infants over a six-year period using a standardized test to identify relationships between outcomes and birth weight, and participation in early intervention programs at a one-year follow-up. Average Mental Development Indices were obtained for the majority of infants across all birth weight categories with the smallest group (500-750 grams) scoring significantly lower than infants in all other categories. Infants who did not participate in early intervention scored better which suggests this group was healthier and less likely to need intervention services. Further clarification of the salient components of early intervention is recommended in future studies.

Analysis of Variance↗

PubMedDate not supplied

ACE inhibition in the 1990s.

Angiotensin-converting enzyme (ACE) inhibitors are now widely prescribed for the treatment of hypertension and heart failure. Their increasing popularity is based on impressive results from studies of efficacy in clinical situations and the realisation that they may have advantages over conventional treatment. This review will highlight some of the recent advances in our knowledge of the role of ACE inhibitors and will develop a rational approach to prescribing.

Angiotensin-Converting Enzyme Inhibitors↗