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Biomedical subjects

T Harper

Publications and source records attributed to T Harper.

17 recordsLinked to original sources
PubMed2000

Medicinal plants used for dogs in Trinidad and Tobago.

This paper documents ethnoveterinary medicines used to treat dogs in Trinidad and Tobago. In 1995, a 4-stage process was used to conduct the research and document the ethnoveterinary practices. Twenty-eight ethnoveterinary respondents were identified using the school-essay method, which is a modified rapid rural appraisal (RRA) technique. Semi-structured interviews were held with these respondents as well as with 30 veterinarians, 27 extension officers and 19 animal-health assistants and/or agricultural officers, and the seven key respondents that they identified. The final step involved hosting four participatory workshops with 55 of the respondents interviewed to discuss the ethnoveterinary data generated from the interviews and to determine dosages for some of the plants mentioned. Supplementary interviews were conducted in 1997 and 1998. Seeds of Carica papaya, and leaves of Cassia alata, Azadirachta indica, Gossypium spp., Cajanus cajan and Chenopodium ambrosiodes are used as anthelmintics. The anthelmintics Gossypium spp. and Chenopodium ambrosiodes are the most frequently used species. Crescentia cujete pulp, Musa spp. stem exudate, the inside of the pods of Bixa orellana, leaves of Cordia curassavica and Eclipta alba plant tops are used for skin diseases. Musa spp. stem exudate, seeds of Manilkara zapota, Pouteria sapota and Mammea americana and leaves of Cordia curassavica, Scoparia dulcis and Nicotiana tabacum are used to control ectoparasites. Dogs are groomed with the leaves of Cordia curassavica, Bambusa vulgaris and Scoparia dulcis. Psidium guajava buds and leaves and the bark of Anacardium occidentale are used for diarrhoea. Owners attempt to achieve milk let-down with a decoction of the leaves of Stachytarpheta jamaicensis. The plant uses parallel those practised in human folk medicine in other Caribbean countries and in other tropical countries.

Animals↗
PubMed2000

Asthma.

Explore the source record for details and available documents.

Adult↗
PubMed2000

The feasibility of a porcine model of acute coronary occlusion and reperfusion using off-pump coronary artery bypass grafting.

We developed an open-chest porcine model of acute coronary occlusion and surgical reperfusion, and attempted to prevent intra-operative ischaemic ventricular fibrillation (VF) by a Retrograde Intracoronary Glyceryl trinitrate (RIG) infusion into the occluded vessel. Five Yorkshire pigs (weight 50 +/- 1.1 kg), randomized into 3 groups, underwent median sternotomy under general anaesthesia. One pig (Group 1, control) underwent sternotomy and pericardiotomy only. Four pigs underwent acute left anterior descending (LAD) coronary occlusion. Two pigs were not reperfused (Group 2). Two pigs underwent surgical reperfusion (Group 3) via left internal mammary artery (LIMA) grafting to the LAD using the Off-Pump Coronary Artery Bypass (OPCAB) technique. Ischaemic injury was assessed using 7-lead electrocardiography (ECG) and transthoracic/epimyocardial echocardiography (ECHO). Group 1: transient intraoperative hypotension and VF occurred. Successful resuscitation and 10-week survival (until sacrifice) with normal left ventricular (LV) function was achieved. Group 2: there were ECG and ECHO evidence of acute LV ischaemic dysfunction in both pigs. The surviving pig had persistent anterior hypokinesis at 8 1/2 months. The other died intra-operatively following progressive ischaemic LV dysfunction despite resuscitative attempts. Group 3: the surviving pig had normal LV function at 8 months. Initial anterior LV akinesis normalized within 7 days. The other developed post-occlusion haemodynamic instability and died intra-operatively despite reperfusion. In this porcine model, acute LAD artery occlusion modified by the novel RIG infusion technique, followed by surgical reperfusion (OPCAB) is feasible. This model would facilitate further development of OPCAB surgical expertise and understanding of the pathophysiology of ischaemia-reperfusion injury.

Animals↗
PubMed1999

Special considerations in breast cancer risk and survival.

Experimental and clinical evidence suggests that breast neoplasia appears to be a hormone-dependent process that may also be influenced by dietary factors in many women. Conflicting reports on the relationship between exogenous hormones and the development, progression, and recurrence of breast cancer are critically examined in this report. The absolute breast cancer risk associated with either hormone replacement therapy or oral contraceptive use has not been clearly defined. Data from some large prospective studies have actually documented lower mortality rates for women taking hormone replacement compared with those for women who did not have hormone replacement therapy. In this regard, age, duration of use, and preexisting breast cancer risk factors must be taken into account. Although the results of two major prospective clinical trials addressing the role of timing of surgery within the menstrual cycle are forthcoming, the majority of studies have found no consistent association between timing of surgery and breast cancer survival. Recently reported prospective randomized data showing that selective-estrogen-receptor-modulators can act as effective chemoprevention agents in women at increased risk for breast cancer development are presented. Finally, information regarding the effect of dietary manipulation on breast cancer risk and survival is reviewed.

Breast Neoplasms↗
PubMed1994

Preferred real-ear insertion gain on a commercial hearing aid at different speech and noise levels.

In the present study, we measured preferred real-ear insertion gain (REIG) under different levels of speech and noise to assess whether current automatic gain control (AGC) and automatic signal processing (ASP) hearing aids are operating optimally. Preferred REIG for optimal speech clarity was determined under seven speech and noise conditions. In four conditions, speech (discourse passages) was varied from 55 dB SPL to 85 dB SPL in 10-dB steps at a fixed signal-to-noise ratio (S/N) of +5. In the remaining conditions, speech was fixed at 65 dB SPL while the noise level was varied in 5-dB steps to yield S/Ns from +10 to -5. The results showed that subjects selected less gain as speech or noise levels were increased. In general, less overall gain was selected as speech level was increased, and less overall gain, especially in the low-frequency region, was selected as the S/N ratio became progressively poorer. These results are discussed in relation to how hearing aids with adaptive frequency/gain responses should respond to varying input levels to achieve optimal clarity of speech.

Adult↗
PubMed1989

Development of compliance chamber diaphragms with reduced permeability.

The implantable ventricular assist systems currently undergoing clinical readiness testing shuttle the displaced gas between the non-blood side of the pumping diaphragm and an elastic chamber generally called a "compliance chamber" or variable volume device. The movement of the stored gas allows the pump to fill and empty without compression or expansion of the gas behind the pump diaphragm. The material used for the construction of compliance chambers should be fatigue resistant to withstand the 63 million flexes per year of the blood pump. The material should also be biocompatible and highly impervious to gases. Significant diffusion of gases from the compliance system necessitates external make-up gases to somehow be added to the internal system. Material selection is complicated by the fact that most fatigue-resistant elastomers also have high gas permeability. In order to solve this problem, bilayer compliance chambers have been developed using biocompatible and fatigue-resistant polyolefin rubber comolded with relatively impervious butyl rubber.

Assisted Circulation↗
PubMed1982

Leukotriene C4 and D4 formation by particulate enzymes.

The homogenate of rat basophilic leukemia cells, when incubated with arachidonic acid, glutathione, and calcium, formed 3 isomers of 5,12-dihydroxyeicosatetraenoic acid and 2 isomers of 5,6-dihydroxyeicosatetraenoic acid, as well as leukotriene (LT) C4 and D4. The products were identified by high pressure liquid chromatography, ultraviolet spectral analysis, co-migration with standards, bioassay, and gas chromatography-mass spectrometry. The enzymes responsible for the formation of LTC4 and LTD4 from LTA4 were found in the 10,000 x g pellet and, therefore, appear to be particulate. The possibility that these enzymes are bound to the cell membrane suggest that the formation of these leukotrienes might be important in the basophil and mast cells release reaction.

Animals↗