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Biomedical subjects

B Wood

Publications and source records attributed to B Wood.

At least 91 records · Page 5Linked to original sources
PubMed1994

Paranthropus boisei: an example of evolutionary stasis?

Of the presently recognised early hominid species, Paranthropus boisei is one of the better known from the fossil record and arguably the most distinctive; the latter interpretation rests on the numbers of apparently derived characters it incorporates. The species as traditionally diagnosed is distributed across approximately one million years and is presently confined to samples from East African sites. The hypodigm has been examined for evidence of intraspecific phyletic evolution, with particular emphasis on the areas best represented in the fossil record, namely the teeth and mandible. The results of this examination of 55 mandibular and dental variables which uses the gamma test statistic for the detection of trend, and nonparametric spline regression (Loess regression) for investigating pattern and rate of temporal change, show that within Paranthropus boisei sensu stricto most evidence of temporally related morphological trends relates to the morphology of the P4 crown. There is little or no evidence of any tendency to increase in overall size through time. Fossils from the Omo Shungura Formation and West Turkana which have been recovered from a time period earlier than the P. boisei sensu stricto hypodigm resemble the latter taxon in some features, but differ from it in aspects of cranial morphology. There is insufficient fossil evidence of the earlier taxon to tell whether it changes through time, but when trends of 47 mandibular and dental variables are assessed across the combined East African "robust" australopithecine sample, there is evidence for a relatively abrupt change around 2.2-2.3 Myr in approximately 25% of the dental and mandibular remains. Some of these changes correspond with the temporal trends within P. boisei sensu stricto, but others, such as mandible height, do not. If the earlier material is ancestral to P. boisei sensu stricto, evidence from the teeth and jaws is consistent with a punctuated origin for the latter taxon.

Africa, Eastern↗
PubMed1994

Acquired immunodeficiency syndrome-related lymphoma of the lung presenting as empyema thoracis.

B-cell lymphoma in patients infected with the human immunodeficiency virus is usually a disseminated process that occasionally involves the lungs. Surgical diagnosis is often necessary to distinguish this from other neoplasms or opportunistic infections of the lung. We report a case of pulmonary B-cell lymphoma in a patient infected with human immunodeficiency virus who presented with a left empyema thoracis and an associated left lower lobe abscess secondary to bronchial obstruction. Resection was performed and the patient subsequently recovered from the acute process and survived an additional 6 months. This report demonstrates that surgical intervention may be necessary for both the diagnosis of pulmonary lymphoma and the definitive management of infectious complications that may arise as a result of pulmonary neoplastic disease in patients with acquired immunodeficiency syndrome.

Adult↗
PubMed1994

A new laser-ultrasound transducer for medical applications.

A new type of probe is presented, which combines an ultrasound receiver constructed from piezoelectric polymer materials with a coaxial optical fibre for laser-induced ultrasound. The initial application of this probe, which may be further miniaturized, is in intra-arterial imaging and therapy. Overall diameters of the prototype probes presently range from 2.5 mm to 10.0 mm. Pulsed laser beams are introduced through the optical fibre to form a photoacoustic source within the material under investigation. Ultrasonic waves are induced in the material due to the photo-acoustic effect and received on return by a forward-looking piezoelectric polymer transducer. In principle, other high-power laser beams can also be introduced through the same optical fibre for therapeutic use. Initial development and characterization of this combined probe is reported in this paper, together with some results.

Acoustics↗
PubMed1994

The use of macrophytes in bioremediation.

The development of reedbed technology for bioremediation is reviewed. The future development, potential and implementation of these systems are considered in detail together with the cost effectiveness and ease of maintenance.

Journal Article↗
PubMed1994

Coalitions and family problem solving with preadolescents in referred, at-risk, and comparison families.

This study tested the hypothesis that the mother-father coalition, parent-child coalitions, and parental warmth expressed toward the child are associated with family problem solving in families with a preadolescent child referred for treatment of behavior problems (n = 30), families with a child at-risk for conduct disorder (n = 68), and a sample of comparison families (n = 90). Referred and at-risk families displayed less effective problem solving. A regression analysis, which controlled for gender of the child, family structure, family income, marital satisfaction, and severity of child problems, showed that strong parental coalitions were linked to low levels of family problem solving in at-risk and referred families. Parent-child coalitions had little apparent impact while parental warmth was highly correlated with better family problem solving. The results may be interpreted as evidence for a tendency for parents in at-risk and referred families to "scapegoat" a preadolescent during family problem-solving sessions. This may undermine progress on family problem solutions and may complicate family-based prevention and treatment programs that use family problem-solving sessions.

Adolescent↗
PubMed1994

Exercise blood pressure response and skeletal muscle vasodilator capacity in normotensives with positive and negative family history of hypertension.

OBJECTIVE: To study exercise blood pressure response in association with exercising muscle maximal vasodilatory capacity in normotensives with a positive and negative family history of hypertension. SUBJECTS: Twenty-eight normotensive healthy subjects were recruited. Of these, two females and 13 males had a positive, and three females and 10 males had a negative, family history of hypertension. METHODS: Both groups of subjects rode a bicycle ergometer while systolic blood pressure, diastolic blood pressure and heart rate were measured at 30%, 60% and peak oxygen uptake rate. The vasodilatory capacity was examined in the lower leg by measuring the minimal vascular resistance during peak reactive hyperemia after 10 min arterial occlusion. RESULTS: Age, body weight, resting blood pressure, peak oxygen uptake rate and casual lower leg vascular resistance were not significantly different between the two groups of subjects. Significantly higher exercise systolic blood pressure (9%) and diastolic blood pressure (9%) were seen in the subjects with positive family history of hypertension compared with the subjects with negative family history of hypertension. Exercise heart rate was significantly higher in the subjects with negative than in those with positive family history of hypertension. The vascular resistance at peak vasodilation was 22% higher in the subjects with positive than in the subjects with negative family history of hypertension. CONCLUSIONS: This study demonstrates that the dynamic exercise blood pressure is exaggerated and skeletal muscle vasodilatory capacity is limited in normotensives with genetic risk of hypertension. This suggests that the higher pressor response to physical stress that is found in normotensives with a family history of hypertension may be attributed to the resistance vessels in the exercising muscle.

Adult↗
PubMed1993

The interparental relationship and family problem solving with preadolescent males.

This study examines associations between the quality of the interparental relationship and how well 68 family triads (mother, father, preadolescent son) solved salient problems which arose at home. Four aspects of the interparental relationship (marital satisfaction, parental agreement, conflict during family problem solving, and parental coalitions) were included in a regression analysis which controlled for family structure and child externalizing. A longitudinal design assessed families when mean child age was 9.7 years and 2 years later. Parental agreement consistently facilitated family problem solving. However, strong parental coalitions inhibited family problem solving, which may be attributed to frustrated autonomy needs of preadolescent males in response to the parental coalition. Stepfamilies had less effective problem solving at Time 1. The results confirm the benefits of parental agreement to child outcomes via enhanced family problem solving but show a reverse effect when agreement occurs in the context of coalitions against a preadolescent son.

Child↗
PubMed1993

Sexual harassment of health care students by patients.

1. Forty percent of the 158 nursing and occupational therapy students surveyed reported being victims of sexual harassment. 2. When confronted with sexual advances or assaults, students used previously learned coping strategies. Thirty-nine percent ignored the behavior or joked about it. 3. A training program was designed and implemented to make students feel better able--and more empowered--to handle sexual harassment.

Adolescent↗
PubMed1993

Peritonitis associated with intra-abdominal pathology in continuous ambulatory peritoneal dialysis patients.

Features helpful in diagnosis and associated with death were evaluated in 26 episodes of peritonitis associated with intra-abdominal pathology (IAP) in continuous ambulatory peritoneal dialysis (CAPD) patients. Culture of multiple enteric pathogens, or of a single unusual enteric pathogen, from the dialysate was useful for diagnosis in 22/26 instances. Other diagnostic features (fecal material in dialysate, diarrhea containing dialysate, increasing free air in the abdominal cavity) were infrequently found. A comparison of patients who died (n = 11, 42%) and those who survived revealed that death was associated with bowel gangrene (5/6 died), recovery of bacteroides from the dialysate, more frequent and severe comorbid conditions (bacteremia, pneumonia, intra-abdominal and intracerebral bleeding, septic shock, hepatic failure), the development of severe malnutrition and thrombocytopenia during infection, and multiple surgical procedures until the diagnosis was established. Peritonitis associated with intra-abdominal pathology in CAPD patients is a severe infection with considerable diagnostic difficulty and high mortality. Early exploratory laparotomy upon suspicion of the nature of the peritonitis, usually raised by the recovery of enteric pathogens from the dialysate, may improve mortality.

Gastrointestinal Diseases↗
PubMed1992

Origin and evolution of the genus Homo.

It is remarkable that the taxonomy and phylogenetic relationships of the earliest known representatives of our own genus, Homo, remain obscure. Advances in techniques for absolute dating and reassessments of the fossils themselves have rendered untenable a simple unilineal model of human evolution, in which Homo habilis succeeded the australopithecines and then evolved via H. erectus into H. sapiens-but no clear alternative consensus has yet emerged.

Africa↗