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Biomedical subjects

A Jamieson

Publications and source records attributed to A Jamieson.

At least 55 records · Page 3Linked to original sources

Home care in old age: a lost cause?

I consider policy trends and the provision of home care for frail elderly people in four countries: Denmark, the United Kingdom, Germany, and the United States. The differing natures of the health and social services systems of each country and the welfare ideologies that underlie them have affected the expansion of home care for this group of people. Hence, Denmark--and to a lesser extent Britain--has relatively well developed networks of home care services, in contrast to Germany and the United States. However, any significant shift away from predominantly medical and institutional care to more home-based, social care is highly unlikely.

Aged↗

Antibodies to calcitonin-gene related peptide reduce inflammation induced by topical mustard oil but not that due to carrageenin in the rat.

The influence of prior immunization to calcitonin gene-related peptide (CGRP) was examined on responses in two models of inflammation plasma: protein extravasation following topical application of mustard oil to the hind paw, and changes in paw volume following subplantar injection of carrageenin. In rats with antibodies to CGRP, there was an approximately 50% decrease compared to the control animals in extravasation, measured by the Evans blue method after topical mustard oil. In contrast, there was no difference in the inflammatory response to carrageenin in control and immunized rats. The results indicate that CGRP, which is probably released from the peripheral endings of cutaneous primary afferents, plays a role in the inflammatory response to mustard oil, but not carrageenin.

Administration, Topical↗

Early graft function following heart and lung transplantation.

Fifty-one patients underwent heart-lung transplantation between April 1984 and October 1988. The first five donor organs were removed in an adjacent operating theatre. Organs were subsequently removed from distant centres. The method of preservation consisted of cold cardioplegic arrest of the heart using St. Thomas' solution, followed by a simple, cold pulmonary artery flush of a lung perfusate developed at Papworth Hospital. Administration of the solution was preceded by an infusion of prostacyclin into the pulmonary artery during preliminary dissection of the donor organs. The total ischaemic time ranged from 48 to 51 min (mean 49.6 min) for the near procurement group and from 70 to 249 min (mean 154.2 min) for the distant procurement group. There were no primary organ failures. Function of the lungs was assessed by gas exchange, pulmonary function tests, time to extubation, and survival data. Serial radiological studies were used to monitor graft performance in the postoperative period. We report here on our clinical experience of early graft function following heart and lung transplantation.

Adolescent↗

A new age for older people? Policy shifts in health and social care.

This paper considers health and social policies for older persons from a cross-national perspective and attempts to uncover some of the factors influencing policy formulation and implementation. The focus is on community care, its meanings and practical implementation. Examples are drawn from Western Europe and the U.S.A. to illustrate and explain differences and similarities. Two sets of explanatory factors are considered crucial. First, the structure of health and social care systems create incentives for clients, care providers and planners in certain directions. The degree of organisational fragmentation and of public control are seen to be the most important structural factors. Second, it is argued that the political and ideological context within which health and social systems operate must be understood if one is to assess the likely directions of future policies.

Aged↗

The role of substance P and calcitonin gene-related peptide in neurogenic plasma extravasation and vasodilatation in the rat.

Immunohistochemistry combined with retrograde tracing has been used to show that of the afferent neurons supplying the dorsomedial surface of the hind paw, approximately 30% contain substance P and 50% calcitonin gene-related peptide immunoreactivity. Stimulation of the saphenous nerve causes plasma extravasation and antidromic vasodilatation in this area of skin. The roles of calcitonin gene-related peptide and substance P released from peripheral afferent endings in mediating these effects were examined using immunoneutralization. In pilot experiments, the binding of radiolabelled peptide to the immunoglobulin fraction of calcitonin gene-related peptide and substance P antisera was characterized in quasi-physiological conditions. Systemic administration of either substance P or calcitonin gene-related peptide antibodies caused a significant decrease (P less than 0.05) in plasma extravasation measured by the Evans Blue method in response to topical application of mustard oil (0.5%) to the skin, or of capsaicin (5 microM) to the saphenous nerve. Topical application of mustard oil also produced a 52.9 +/- 5.1% increase in skin red cell flux. This increase was significantly decreased by both substance P and calcitonin gene-related peptide antibodies. The results suggest that both peptides are involved in mediating neurogenic inflammatory responses.

Animals↗

Women and the obstructive sleep apnea syndrome.

Twenty-seven women referred to a sleep disorders clinic for symptoms of obstructive sleep apnea syndrome (OSAS) during one year were systematically analyzed after polygraphic monitoring of sleep and cephalometric x-ray examination. Our subjects, one-third of whom were premenopausal, comprised approximately 12 percent of the total OSAS population seen. Women with OSAS were compared with 110 OSAS men and with a group of 16 women without OSAS but referred to orthodontists for mild dental malocclusion. Women with OSAS were massively obese, much more so than their male counterparts. There was no significant difference between pre- and postmenopausal women, with the exception of the respiratory disturbance index (RDI), which was lower in the postmenopausal group despite similar morbid obesity (seemingly better tolerated by women with OSAS than by men with the same syndrome) and long mandibular plane-hyoid bone distance. The significantly higher RDI noted in premenopausal women, despite equally massive obesity and upper airway abnormalities, is thought to be related to hormonal status and better arousal response. Chronic obstructive lung disease (COLD) seen in a subgroup of women with OSAS did not differentiate this subgroup from the other OSAS patients when oxygen saturation during sleep, frequency of abnormal respiratory events and sleep variables were considered. Massive obesity is the dominant factor for the appearance of OSAS in women.

Adolescent↗

Obstructive sleep apnea and cephalometric roentgenograms. The role of anatomic upper airway abnormalities in the definition of abnormal breathing during sleep.

In a six-month period, 157 obstructive sleep apnea syndrome (OSAS) patients seen consecutively in clinic had standardized cephalometric roentgenograms and underwent polygraphic monitoring during sleep. Different variables, including cephalometric landmarks, body mass index (BMI), and polygraphic results (particularly degree of O2 saturation and number of abnormal breathing events), were statistically analyzed. As a rule, OSAS patients had upper airway anatomic abnormalities and an elevated BMI: massive obesity was associated with less anatomic abnormality, less nocturnal sleep disruption, and longer total sleep time (TST). Patients having a high respiratory disturbance index (RDI) were more likely to have upper airway anatomic abnormalities; they slept for a shorter time and had increased stage 1 non-rapid eye movement (NREM) sleep but decreased stage 3 and 4 and REM sleep. Long mandibular plane to hyoid bone (MP-H) distance and width of the posterior airway space (PAS) (space behind the base of the tongue) were statistically significant predictors of elevated RDI. The cephalometric variables were much less useful for predicting frequency of O2 saturation drops below 80 percent. The patient population can be subdivided into (a) patients with clear anatomic abnormalities and low BMI, (b) patients with morbid obesity with few abnormal cephalometric measurements, and (c) patients who have variably increased BMI and abnormal cephalometric measurements. This is the largest group. We concluded that standardized cephalometric roentgenograms can be useful in determining the appropriate treatment for OSAS patients.

Adult↗

Long-term outcome for obstructive sleep apnea syndrome patients. Mortality.

As the actual mortality and morbidity of obstructive sleep apnea syndrome (OSAS) have been unknown heretofore, we undertook a follow-up study of 198 OSAS patients seen at the Stanford Sleep Disorders Clinic between 1972 and 1980, for whom either tracheostomy (71 patients) or weight loss (127 patients) had been recommended. At five-year follow-up, all of the deaths (14) had occurred among those conservatively treated with weight-loss (a mortality rate of 11 per 100 patients per five years). These patents also had a higher five-year crude vascular mortality rate: 6.3 per 100 patients per five years, with an age-standardized vascular mortality rate of 5.9 per 100 patients per five years (95 percent confidence interval [CI] 2.5-11.6) vs 0 per 100 for the surgically treated population; this despite a lower mean apnea index (43 versus 69) and a lower mean body mass index (31 versus 34 kg/m2) in the conservatively treated group. With the fictional adjunction of one possible death at five-year follow-up in the surgically treated group, the age-adjusted odds of vascular mortality at five years for the conservatively treated group was 4.7. Our data therefore encourage "aggressive" treatment for patients with OSAS.

Adolescent↗

Determinants of respiratory disturbance and oxygen saturation drop indices in obstructive sleep apnoea syndrome.

Although chronic sleep fragmentation and oxygen saturation (Sao2) drops alone do not induce obstructive sleep apnoea (OSA), both are part of the feedback loop leading to obstructive sleep apnoea syndrome (OSAS). To determine factors in respiratory disturbance and Sao2 drops, we used polysomnographic and cephalometric data from 120 OSAS patients to construct a model which we then applied prospectively to 25 new OSAS patients, calculating the correlation between observed and predicted values. We found body mass index and the amount of stage 1 non-rapid eye movement sleep to be significant variables when considering both the respiratory disturbance index (RDI) and Sao2 drops. Posterior airway space was also a significant variable for RDI. Forced expiratory volume in one second, expressed as the percentage of forced vital capacity (FEV1/FVC), was significant when considering Sao2 drops. Upper airway abnormalities were also significant variables in the models and must be considered when treating OSAS patients.

Female↗

Analogues of substance P. Peptides containing D-amino acid residues in various positions of substance P and displaying agonist or receptor selective antagonist effects.

Agonist and antagonist analogues of substance P were synthesized by replacing at least two of the amino acid residues with D-Trp, D-Phe, D-Val, or D-Pro residues. The syntheses of these compounds were achieved by solid-phase methodology using the hydroxymethyl resin. The analogues were tested for agonist and antagonist activity on guinea pig ileum and rat spinal cord preparations. Two types of antagonists were obtained. The first type of compounds, e.g., [N alpha-Z-Arg1,N epsilon-Z-Lys3,D-Trp7,8,D-Met11]-SP-OMe (1), antagonized SP and SP(6-11)-hexapeptide on the ileum but only SP(6-11)-hexapeptide on the spinal cord. The second type of antagonists, e.g., [N alpha-Z-Arg1,N epsilon-Z-Lys3,D-Pro9,10]-SP-OMe (17), were inactive on the ileum but were potent antagonists of the hexapeptide on the spinal cord. Two of the antagonists, [N alpha-Z-Arg1,N epsilon-Z-Lys3,D-Trp7,8,D-Met11]-SP (3) and [D-Trp7,8,9]-SP (43), were also tested in vivo. Both of these depressed hypotensive responses to SP and SP(6-11)-hexapeptide in rabbits.

Amino Acid Sequence↗

Antagonists of substance P. Further modifications of substance P antagonists obtained by replacing either positions 7, 9 or 7, 8 and 11 of SP with D-amino acid residues.

Antagonists of SP and the C-terminal (6-11)-hexapeptide have been obtained by multiple D-amino acid substitutions in various positions of SP and by protecting the N alpha-Arg1 and N epsilon Lys3 amino groups with benzyloxycarbonyl groups. On the guinea pig ileum a number of these antagonized both SP and the hexapeptide. Except [N alpha-Z-Arg1,D-Pro2,N epsilon-Z-Lys3,Asn5,Arg6,D-Phe7,D-Trp9]-SP-OMe (4) and the corresponding amide 7, which were more potent antagonists of SP than the hexapeptide, all the others, e.g., [N alpha-Z-Arg1,D-Pro2,4,N epsilon-Z-Lys3,D-Phe7,8,Sar9,D-Met11]-SP-OMe (9), [N alpha-Z-Arg1,D-Pro2,4,N epsilon-Z-Lys3,D-Phe7,8,Sar9,MeLeu10,D-Met11]-SP -OMe (11), were more potent antagonists of the hexapeptide. On the rat spinal cord preparation, most of the antagonists were only active against the hexapeptide. A few antagonized SP, but these also reduced carbachol or both carbachol and glutamate responses. Two of the antagonists, [D-Pro2,Asn5,Lys6,D-Phe7,D-Trp9]-SP-OMe (2) and [Boc-D-Pro4,D-Phe7,8,Sar9,D-Met11]-SP(4-11)-OMe (10), were inactive on the ileum but still antagonized the hexapeptide on the spinal cord. The smallest peptides to antagonize SP and the hexapeptide were two heptapeptides, 6 and 21, [Z-Asn5,Arg6,D-Phe7,8,Gly9 psi (CH2S)D-Leu10,D-Met11]-SP(5-11)-OMe (21) being more potent than 6. None of the antagonists showed significant analgesic activity without side effects. Some of the antagonists were shown to release histamine from isolated rat peritoneal cells.

Amino Acid Sequence↗

Obstructive sleep apneic patients have craniomandibular abnormalities.

One hundred fifty-five unselected obstructive sleep apneic patients seen in succession had cephalometric roentgenograms and polygraphic recordings performed. These patients were compared to a group of 41 subjects who had consulted orthodontists for malocclusion and had no clinical indication of sleep apnea. The cephalometric landmarks were also compared to those published as normative data in the literature. The limits of "normalcy" were conservatively defined as mean +/- 2 standard deviations. Only two obstructive sleep apneic patients had normal cephalometric landmarks and 150 of the 155 patients had at least two significantly different landmarks from the normative data in the literature. The common findings were a retroposition of the mandible, a different cranial base flexure with a nasion-sella-basion angle more acute than expected, and a displacement of the hyoid bone to a lower position than expected. These combined changes reduced the space occupied by soft tissues anchored on the skull and mandible, and the length of the soft palate was increased.

Abnormalities, Multiple↗

Quantitative variation in cystic fibrosis-associated proteins in cystic fibrosis patients, carriers, and controls.

Serum samples from patients with cystic fibrosis (CF), obligate heterozygotes, and normal controls have been examined by isoelectric focusing (IEF). Our results suggest that cystic fibrosis protein (CFP) is a normal serum protein exhibiting quantitative variation primarily dependent on possession of the CF allele. It is concluded that detection of CFP by IEF is an inappropriate screening test for the CF gene due to lack of specificity.

Alleles↗

Further evidence for multiple tachykinin receptors.

Rank order potency data for substance P (SP), physalaemin and eledoisin have been determined in a variety of assays in vitro. On the guinea-pig field stimulated vas deferens, physalaemin was approximately eight and five times more potent than eledoisin and SP respectively whereas in the rat field-stimulated vas deferens, eledoisin was approximately five times more potent than either physalaemin or SP. It would appear that the guinea-pig preparation has a preponderance of 'P'-receptor subtypes, whereas the rat preparation contains mainly 'E'-receptor subtypes. We have attempted to validate the hypothesis that there are multiple tachykinin receptors. Experiments have been performed with the guinea-pig urinary bladder in vitro, using phenoxybenzamine (20 microM, 30 min) to alkylate receptor sites and using excess eledoisin (0.2-0.4 microM, 30 min) to protect receptors selectively against the effects of this agent. Our results showed that after pretreatment with phenoxybenzamine, the responses to eledoisin were significantly attenuated. Moreover, in the presence of excess eledoisin it was found that phenoxybenzamine was unable to produce any significant reduction of the subsequent responses. This difference between the responses to eledoisin and to other agonists suggests the existence of at least two different receptor subtypes for the tachykinins.

Alkylation↗

Evaluation of a scavenging system for use with inhalation anaesthesia techniques in rats.

A minimum fresh gas flow of 1 litre per minute per mask and an inspired concentration of 2-3% halothane was required in induce anesthesia in rats in 1-2 min. Anaesthesia was maintained with an inspired concentration of 1.5-2% halothane. Arterial carbon dioxide concentration increased during anaesthesia and was reduced by increasing the flow of fresh gas. Using the apparatus described here, halothane vapour concentration in the operator's breathing zone was 5 ppm. Prior to its introduction, levels of 250 ppm had been recorded in a poorly-ventilated animal room.

Air Pollution↗