Biomedical subjects

J Ferguson

Publications and source records attributed to J Ferguson.

At least 199 records · Page 11Linked to original sources

PubMed1993

Enhancing maternal interactive behavior and child social competence in low birth weight, premature infants.

Effects of a comprehensive early intervention program for low birth weight, premature infants--the Infant Health and Development Program--on mother-child interaction were examined at 30 months (N = 683). Small significant positive effects were found: Intervention mothers had higher ratings on quality of assistance; intervention children had higher ratings on persistence and enthusiasm and on an overall child rating of competence and involvement and lower ratings on percentage of time off-task; intervention dyads were rated as more synchronous. Of a set of initial status variables indexing biological and environmental risk, only 2 treatment interactions were found. Intervention group black children had higher ratings on enthusiasm and lower percentage of time off-task. Independent of treatment, maternal ethnicity and education were significant predictors of maternal and dyadic ratings, while ethnicity and birth weight predicted child ratings. Implications for early intervention and center-based care are discussed.

Adult↗

PubMed1993

Anti-D concentrations in fetal and maternal serum and amniotic fluid in rhesus allo-immunised pregnancies.

OBJECTIVE: To investigate the relation between anti-D concentrations in maternal serum, fetal serum and amniotic fluid, and the development of fetal anaemia. DESIGN: Observational cross sectional and longitudinal study. SETTING: Regional referral centre. SUBJECTS: Sixty-one women undergoing fetal blood sampling at 19 to 36 weeks' gestation for fetal blood and haematocrit estimation for the management of Rh (D) allo-immunisation. Thirty-eight pregnancies (7 with an Rh (D) negative fetus) were tested only once but the rest had two to five fetal blood samplings. INTERVENTIONS: Ultrasound guided fetal blood sampling and amniocentesis, and automated analysis of anti-D antibody quantitation. RESULTS: There were strong correlations between maternal serum, fetal serum and amniotic fluid anti-D concentrations. Analyses of both longitudinal and cross sectional data demonstrated a decrease of the maternal/fetal serum anti-D ratio with gestation. In pregnancies with Rh (D) negative fetuses the maternal/fetal anti-D ratio was significantly lower (P < 0.0001) than in those with Rh (D) positive fetuses. The degree of fetal anaemia (delta haematocrit) was correlated with maternal serum and amniotic fluid anti-D concentrations (r = -0.55, n = 54, P < 0.0001; r = -0.57, n = 44, P < 0.0001, respectively) but there was a weaker correlation with fetal serum anti-D (r = 0.37, n = 54, P < 0.01). CONCLUSION: Anti-D concentrations in maternal serum, fetal serum and amniotic fluid are correlated with fetal anaemia. The decrease in maternal/fetal anti-D ratio with gestation suggests an increase in placental permeability for anti-D with advancing pregnancy.

Amniotic Fluid↗

PubMed1993

Contact allergy to sunscreen chemicals in photosensitivity dermatitis/actinic reticuloid syndrome (PD/AR) and polymorphic light eruption (PLE).

From 1989-1991, 214 patients (45 PD/AR, 54 PLE, 115 controls) were patch tested to a sunscreen series containing 9 constituents. 16/214 (7.5%) patients reacted to one or more sunscreens, with allergy being significantly more common in PD/AR patients (10/45 versus 2/54 PLE and 4/115 contact dermatitis clinic controls). The benzophenone group of sunscreens (mexenone, oxybenzone) were the most frequent sensitizers, accounting for 8 of the 27 positive patch tests observed. Clinicians should consider contact allergy to sunscreens in PD/AR patients as an explanation for exposed-site dermatitis episodes.

4-Aminobenzoic Acid↗

PubMed1993

Short-stay facilities in accident and emergency departments for children.

This paper assesses short stay ward facilities for children in the United Kingdom. The results of a postal questionnaire indicate that 50% of departments surveyed have a short-stay ward. Of these 25% admit small numbers of children. These are mainly children who have sustained trauma-related problems. The potential role of paediatric short-stay ward facilities is discussed.

Child↗

PubMed1993

Homozygous variegate porphyria: an evolving clinical syndrome.

Variegate porphyria is one of the most frequently encountered genetic conditions in South Africa. It is inherited as an autosomal dominant disease and in excess of 300 heterozygous cases have been studied by the Cape Town unit. Despite this, the homozygous condition has not previously been encountered in South Africa. We report two cases of homozygous variegate porphyria, one of whom represents the first South African case. We delineate a syndrome principally characterized by growth retardation, developmental delay, epileptic seizures, photosensitivity and an abnormal porphyrin excretion pattern. In addition we describe, in one case, two features not previously reported: skin disease in areas unexposed to light and a severe sensory neuropathy which may account at least in part for the hand deformities of this disorder.

Bone and Bones↗

PubMed1993

Use of a direct antithrombin, hirulog, in place of heparin during coronary angioplasty.

BACKGROUND: Since the inception of coronary angioplasty, heparin with or without aspirin has been routinely given intraprocedurally to avoid coronary thrombotic complications. Recently, the direct thrombin inhibitor hirulog has been demonstrated to inactivate clot-bound thrombin. The present study was a multicenter dose escalation of hirulog to determine its appropriate dose and feasibility as the sole anticoagulant during coronary angioplasty. METHODS AND RESULTS: At 11 participating centers, 291 patients undergoing elective coronary angioplasty and pretreated with 325 mg aspirin daily were enrolled in sequential groups of intravenously administered hirulog instead of heparin as follows: group 1: bolus, 0.15 mg/kg; infusion, 0.6 mg.kg-1.hr-1 (54 patients); group 2: bolus, 0.25 mg/kg; infusion, 1.0 mg.kg-1.hr-1 (53 patients); group 3: bolus, 0.35 mg/kg; infusion, 1.4 mg.kg-1.hr-1 (44 patients); group 4: bolus, 0.45 mg/kg; infusion, 1.8 mg.kg-1.hr-1 (74 patients); and group 5: bolus, 0.55 mg/kg; infusion, 2.2 mg.kg-1.hr-1 (54 patients). The hirulog infusion was maintained for 4 hours; the primary end point was abrupt vessel closure within 24 hours of the initiation of the procedure. Activated clotting times (ACT) and activated partial thromboplastin times (aPTT) were serially monitored. Abrupt vessel closure occurred in 18 patients (6.2%). By intention to treat, the abrupt closure event rate for groups 1-3 was 11.3% compared with 3.9% in groups 4 and 5 (p = 0.052). There were no significant bleeding complications except for one patient in group 1, who received a two-unit transfusion. A dose-response curve of both ACTs and aPTTs was noted; no coronary thrombotic closures occurred in the small number of patients with ACT > 300 seconds. CONCLUSIONS: The present study documents for the first time that it is possible to perform coronary angioplasty with an anticoagulant other than heparin in aspirin-pretreated patients. Hirulog was associated with a rapid onset, dose-dependent anticoagulant effect, minimal bleeding complications, and at doses of 1.8-2.2 mg/kg, a rate of 3.9% for abrupt vessel closure.

Adolescent↗

PubMed1993

Potent effects of human galanin in man: growth hormone secretion and vagal blockade.

Human galanin (hGAL) is a 30-amino acid neurohormone that has recently been shown to differ significantly from porcine and rat GAL. We investigated the endocrine and cardiovascular effects of hGAL in eight male volunteers. On three separate occasions, each received a 90-min infusion of saline, low dose (33 pmol/kg.min) and high (132 pmol/kg.min) dose hGAL, combined with an iv glucose bolus (to assess effects on insulin and GH release). hGAL was undetectable, 1.4 +/- 0.2 nmol/L, and 3.7 +/- 0.5 nmol/L during control, low dose, and high dose studies, respectively. The half-life of hGAL was 3.5 +/- 0.5 min. GH levels rose significantly in both studies (vs. control) and were not suppressed by hyperglycemia [low dose area under the curve (AUC), 1827 +/- 348 micrograms/min.L (P < 0.05); peak, 19.5 +/- 5.3 micrograms/L; high dose AUC, 1896 +/- 401 micrograms/min.L (P < 0.005); peak, 28.0 +/- 7.5 micrograms/L]. PRL levels rose significantly with the high dose study only (AUC, 12.8 +/- 1.1 micrograms/min.L; P < 0.01). FSH, LH, and catecholamine levels were unchanged. Glucose-stimulated insulin release was not inhibited. There was a dose-dependent increase in pulse rate and a profound decrease in sinus arrhythmia, but no change in blood pressure. These cardiovascular effects have not been reported with studies in humans using GAL of other species. We conclude that hGAL may play an important role in man in modulating GH secretion and cardiac vagal tone, but not insulin release.

Adolescent↗

PubMed1993

Photosensitivity associated with antibacterial agents.

Skin reactions following the interaction of photoactive drugs and ultraviolet or visible radiation are usually rapidly reversible after drug cessation. Within the antibacterial group, photosensitivity to sulphonamides, nalidixic acid, fluoroquinolones and tetracycline members have all been reported. In general such reactions are mild, although rarely some individuals have a severe response. Precise subcellular mechanisms are drug specific, appear complex, and as yet are ill understood. Measures such as drug dosage reduction, the wearing of photoprotective clothing and use of broad spectrum sunscreens can alleviate the problem.

Anti-Infective Agents↗

PubMed1993

I/S interoperability a must in tomorrow's complex healthcare environment.

In the coming age of community health networks, healthcare information systems will have to communicate quickly and easily. Standards must be accepted and endorsed by the healthcare I/S industry if this necessary goal is to be achieved, and visionary healthcare organizations must be willing to take the first steps toward adopting these new systems.

Computer Communication Networks↗

PubMed1993

Granulocyte-macrophage colony-stimulating factor given before dose-intensive cyclophosphamide, etoposide, and cisplatin (DICEP).

Substantial increases in dose-intensity of chemotherapy yield a severalfold increase in complete remission rates and durable responses in several types of malignant disease. Hematopoietic colony-stimulating factors decrease the duration of the resultant severe neutropenia but optimal dosing regimens of these cytokines have not yet been determined. This study was designed to explore the use of both yeast-derived and E. coli-derived GM-CSF given pre- and postchemotherapy with an intensive combination chemotherapy regimen. The chemotherapeutic regimen consisted of cyclophosphamide 5000 mg/m2, etoposide 1500 mg/m2, and cisplatin 150 mg/m2 (DICEP). Patients receiving either yeast-derived GM-CSF (6.5 days) or E. coli-derived GM-CSF (6.0 days) had a shorter duration of severe granulocytopenia with an absolute granulocyte count below 300/microL than patients receiving no GM-CSF (11.0 days, p = 0.0001). Administration of GM-CSF for 6 days immediately preceding DICEP did not further shorten the duration of cytopenia. E. coli-derived GM-CSF given at doses above 5 micrograms/kg was poorly tolerated and offered no hematologic advantage. Lower doses (3 micrograms/kg) of the E. coli product were better tolerated but still produced more toxicities than yeast-derived GM-CSF. The yeast-derived product produced no local skin reactions and decreased the incidence of nonhematologic and all grade 3 or 4 toxicities compared to the control group.

Adult↗

PubMed1993

A review of commonly prescribed oral antibiotics in general dentistry.

The microflora associated with odontogenic infections are typically mixed and of indigenous origin. Streptococcus, peptostreptococcus, peptococcus, fusobacterium, bacteroides, and actinomyces species are the principle microflora isolated from these infections. Penicillin V (phenoxymethyl penicillin) remains the antimicrobial of choice for the initial empirical treatment of odontogenic infections. This agent is safe, highly effective and inexpensive. Amoxicillin has little indication for the routine treatment of odontogenic infections. However, it is the agent of choice for endocarditis prophylaxis, as it produces higher serum levels than penicillin V. Erythromycin may be used for mild, acute odontogenic infections in penicillin-allergic patients. The high incidence of gastrointestinal disturbances and superinfection commonly associated with the ingestion of tetracycline limits its role in general dental practice. Tetracycline may be considered as an alternative therapy for penicillin-allergic patients over the age of 13 who cannot tolerate erythromycin. Clindamycin is very effective against all odontogenic pathogens, but its potential gastrointestinal toxicity relegates it to third- or even fourth-line therapy in general dentistry. Although metronidazole displays excellent activity against anaerobic gram-negative bacilli, it is only moderately effective against facultative and anaerobic gram-positive cocci, and should not be used alone in the treatment of acute odontogenic infections.

Administration, Oral↗

PubMed1993

Voices from family medicine: toward the 21st century. Interview by William B. Ventres and John J. Frey.

Throughout STFM's 25th anniversary year, we illustrated the dynamic history of family medicine using the personal narratives of some of the discipline's founders and early leaders. We have attempted to take the energy of their spoken words and put it on paper for clinician educators to learn from and lead by. For us, as authors, this process has been enriching and has caused us to reexamine and confirm the meanings of our roles as teachers in family medicine. In this final installment, we present five new voices: individuals from succeeding generations of academic family physicians. Like the many others we interviewed but have not included here, these five individuals were identified by colleagues for their demonstrated leadership in the discipline. They and others will help mold the future of family medicine well into the 21st century.

Career Choice↗

PubMed1992

Methodologic issues in clinical evaluation of stenosis severity in adults undergoing aortic or mitral balloon valvuloplasty. The NHLBI Balloon Valvuloplasty Registry.

Although both catheterization and Doppler measures of valvular stenosis severity have been validated, each has specific advantages and limitations, particularly in the setting of balloon valvuloplasty. Invasive valve area and mean pressure gradient recorded immediately before and after aortic (n = 589) or mitral (n = 608) catheter balloon valvuloplasty were compared with Doppler valve area and mean pressure gradient recorded less than 30 days before and 24 to 72 hours after the procedure. For aortic stenosis, Doppler valve area ranged from 0.1 to 1.4 cm2 before and 0.2 to 2.3 cm2 after catheter balloon valvuloplasty. Doppler and invasive aortic valve areas differed by less than or equal to 0.5 cm2 in 99% and by less than 0.2 cm2 in 92% of patients. Linear correlation was higher before versus after catheter balloon valvuloplasty, for both valve area (r = 0.49 vs r = 0.35, p = 0.01) and mean pressure gradient (r = 0.64 vs r = 0.50, p = 0.01). Group mean invasive valve area was slightly smaller before (0.50 vs 0.59 cm2, p less than 0.0001) but was not different after (0.80 vs 0.78 cm2, p = 0.16) catheter balloon valvuloplasty. Variables affecting the valve area differences were cardiac output, aortic regurgitation, heart rate and blood pressure. Mean pressure gradient differences were related to echo quality, blood pressure and mitral regurgitation. For mitral stenosis, 2-dimensional echocardiographic valve area ranged from 0.4 to 2.8 cm2 before and 0.7 to 3.8 cm2 after catheter balloon valvuloplasty. Two-dimensional echocardiography and invasive mitral valve areas differed by less than or equal to 0.5 cm2 in 96% and by less than 0.2 cm2 in 81% of cases. Linear correlation was not different before versus after catheter balloon valvuloplasty for two-dimensional echocardiographic valve area (r = 0.40 vs 0.36), pressure halftime valve area (r = 0.31 vs 0.32) or mean pressure gradient (r = 0.55 vs r = 0.46). Group mean 2-dimensional echocardiography and pressure halftime valve areas were larger than invasive valve areas before (1.09 vs 1.02 cm2, p = 0.001) and smaller after (1.71 vs 2.02 cm2, p less than 0.0001) catheter balloon valvuloplasty. Important variables affecting the differences were mitral regurgitation, interatrial shunt, cardiac output and heart rate. Nonsimultaneous studies, differing volume flow measurements, and the underlying accuracy of each technique largely account for discrepancies between these methods. The clinical use of each will depend on its ability to predict long-term patient outcome.

Adult↗

PubMed1992

In vitro phototoxicity of nifedipine: sequential induction of toxic and non-toxic photoproducts with UVA radiation.

Anecdotal reports suggest that the dihydropyridine calcium antagonist, nifedipine (NIF), may be phototoxic in human skin. We have studied NIF phototoxicity in vitro using UVA fluorescent tubes (Sylvania PUVA). NIF was phototoxic to Candida albicans and induced photohaemolysis both with NIF present during irradiation and with pre-irradiated drug. In V79 hamster fibroblasts, NIF (10 micrograms ml-1) was phototoxic MTT assay) 24 h after irradiation (0-112 kJ m-2); at 7.5 kJ m-2, about 70% of cells were damaged whilst at 37.5 kJ m-2, only about 45% of cells were damaged. A similar pattern was seen with pre-irradiated NIF. Absorption spectroscopy showed that the NIF absorption maximum (Amax approximately 340 nm) blue-shifted to 314 nm at low UVA doses (7.5 kJ m-2 or less) and red-shifted to 345 nm at higher doses (isosbestic point, 325 nm). Thin layer chromatography of irradiated NIF showed a single photoproduct (PP1; Amax approximately 314 nm) formed at 7.5 kJ m-2 or less which disappeared at higher UVA doses to give further photoproducts. PP1 was highly dark toxic to V79 cells (50% damage at about 5 micrograms ml-1) but PP1 pre-irradiated with UVA was non-toxic. Preliminary gas chromatography-mass spectroscopy studies suggest that PP1 is the nitroso derivative of NIF. These results indicate that NIF phototoxicity in vitro is partially mediated by initial formation of a toxic photoproduct (PP1) but, paradoxically, subsequent UVA irradiation may reduce phototoxicity. The NIF concentrations required to induce in vitro phototoxicity are much greater than therapeutic plasma levels. Unless there is skin accumulation of NIF or PP1, our in vitro results suggest that NIF may not be an important skin-photosensitizing agent in vivo.

Animals↗

PubMed1992

Sorghum mitochondrial atp6: divergent amino extensions to a conserved core polypeptide.

Sorghum mitochondrial atp6 occurs as one copy in the line Tx398 and as two copies in IS1112C. In IS1112C a repeated sequence diverged within the atp6 open reading frames. The two open reading frames (1137 bp, atp6-1; 1002 bp, atp6-2) share an identical conserved region of 756 bp but are flanked 5' by divergent extensions of 246 (atp6-1) or 381 bp (atp6-2). Tx398 carried only atp6-2. The breakpoint of the repeated sequence of the conserved core region corresponds to the amino acid sequence Ser-Pro-Leu-Asp, which is the amino terminus of the proteolytically processed yeast ATP6. The 5' extensions of atp6-1 and atp6-2 were similar to those of rice and maize, respectively. Each open reading is transcribed, however nuclear background influenced transcriptional patterns of atp6-2 in IS1112C.

Amino Acid Sequence↗

PubMed1992

Localization of inhaled trimellitic anhydride to lung with a respiratory lymph node antibody secreting cell response.

Male Sprague-Dawley rats were exposed to trimellitic anhydride (TMA) by inhalation (500 micrograms/m3), 4 hours a day, for 1 to 10 days. TMA was localized to lung cells by immunoelectron microscopy. Enzyme-linked immunosorbent assay (ELISA) and Western blot analysis were used in an attempt to localize TMA to lung lavage proteins. The lung-associated lymph node (LALN) B-lymphocyte response was measured by quantitation of immunoglobulin (Ig)G, IgA, and IgM antibody secreting cells specific for TMA rat serum albumin (TM-RSA) by use of the enzyme-linked immunospot assay (ELISPOT) method. The IgG, IgM, and IgA antibody response to TM-RSA in serum and lavage fluid was quantitated by ELISA. Lung injury was assessed by the number of external lung hemorrhagic foci and lung weight. Immunoelectron microscopy localized TMA to alveolar and bronchial cells on all exposure days. ELISA detected trace amounts of TMA haptenized lavage proteins that could not be detected by Western blot analysis. A marked increase occurred in lung injury from day 7 to 10. The LALN IgG, IgA, and IgM antibody secreting cell response to TM-RSA paralleled measures of lung injury. IgG, IgM, and IgA serum and lavage antibody to TM-RSA were correlated with lung injury measures. Lavage and serum IgG antibody levels had the highest correlation with lung injury.

Administration, Inhalation↗

PubMed1992

The effect of heparin versus citrate on blood echogenicity in vitro: the role of platelet and platelet-neutrophil aggregates.

There is no consensus among investigators regarding which anticoagulant to use when studying the causes of in vitro blood echogenicity, despite the fact that heparin and calcium-chelating anticoagulants may have disparate effects due to their differing effects on platelets. This study quantitated the echogenicity of heparinized blood compared to citrated blood and found that it was greater in heparinized blood than in citrated blood when paired samples from the same donor, drawn at the same time were compared. By microscopic examination of the blood, this difference appeared to be due to the formation of platelet and platelet-neutrophil aggregates in the heparinized blood. This hypothesis was tested by comparing the echogenicity of heparinized blood to that of heparinized blood following platelet and white cell depletion. The results showed that taking away platelets and white cells virtually eliminated the echogenicity of heparinized blood; the impact of this result is discussed in the context of in vivo spontaneous contrast.

Animals↗

PubMed1992

Red cell aggregation and the echogenicity of whole blood.

To study the relationship between red cell aggregation and whole blood echogenicity, red cell aggregation was quantitated by a photometric method, whole blood echogenicity was quantitated by videodensitometry and sedimentation rate was quantitated by a modified Westergren method. Changes in red cell aggregation were produced by alterations in the hematocrit. The results showed that red cell aggregation increased in a linear fashion with increases in hematocrit. The sedimentation rate decreased in a linear manner with increases in hematocrit. Whole blood echogenicity showed a biphasic response, with an initial increase in echogenicity, peaking at hematocrits varying from 14-24% and decreasing thereafter. Over the physiologic range of hematocrits, an increase in the formation of red cell aggregates is associated with a decrease in the echogenicity of whole blood. Thus, red cell aggregates were not visible using our ultrasound equipment at physiologic hematocrits, and the echo contrast in blood under our experimental conditions at these hematocrits must represent either plasma spaces, platelet aggregates or possibly white cell aggregates. The association between spontaneous contrast and a propensity for thromboembolism imply that platelet aggregates are the most likely origin of in vivo echo contrast in flowing blood.

Animals↗