Biomedical subjects

M Daniels

Publications and source records attributed to M Daniels.

At least 91 records · Page 5Linked to original sources

PubMed1990

A structured interview version of the Hamilton Depression Rating Scale: evidence of reliability and versatility of administration.

A structured interview version of the Hamilton Depression Rating Scale (SI-HDRS) is described. Data are presented in support of its inter-rater and internal consistency reliability. SI-HDRS scores were reproducible by trained interviewers who lacked psychiatric backgrounds. Test-retest scores of a subset of patients who were interviewed twice (once in person and once by telephone) were highly correlated. Scores on the SI-HDRS did not differ between face-to-face and telephone administration groups, controlling for demographic factors, depression-specific indicators, and social and physical functioning. Since the SI-HDRS does not require a face-to-face interview by an experienced clinician, this instrument can be used economically in large-scale, community-based research projects.

Adult↗

PubMed1990

Surgeons' knowledge, attitude, and use of preoperative autologous blood donation.

Before a comprehensive educational program on preoperative autologous blood donation was begun, 118 surgeons from three different areas of the country were tested to assess their baseline knowledge and attitude about this practice. Test results were correlated with the percentage of eligible patients that the surgeons actually referred for preoperative donation during a period of observation. The purpose of this preliminary effort was to identify areas in the educational program that required emphasis. Overall, the surgeons' attitude toward preoperative donation was quite favorable, but their depth of knowledge varied. Misunderstandings may have led to diminished use of this service (eg, about 50% didn't realize that many patients with medical conditions or low hematocrits are permitted to donate). However, it is not clear that simply bolstering surgeons' knowledge will increase their appropriate use of preoperative donation. When all 118 surgeons were studied, their knowledge and attitude were unrelated to the percentage of eligible patients referred. However, when 44 surgeons who managed the largest number of eligible patients were analyzed separately, their use of preoperative donation was directly correlated with their knowledge and attitude. The local awareness of AIDS also significantly influenced the use of this service. It is proposed that knowledge of preoperative donation may be important for inducing surgeons to begin referring patients for this service. Once a pattern of successful participation is established, referral seems to increase with the acquisition of working knowledge.

Blood Transfusion, Autologous↗

PubMed1990

Combination chemotherapy with oral etoposide plus intravenous cyclophosphamide in liver metastases of breast cancer.

Sixteen patients with hepatic metastases of histologically documented breast cancer were treated with etoposide (VP 16-213) and cyclophosphamide. Previously, 6 had shown relapse in the liver after adjuvant chemotherapy, 2 had failed to respond to another chemotherapy combination, and 8 had never undergone chemotherapy. Fifty percent responded to treatment, including 1 complete remission and 7 partial responses. Median survival was 16 months and median duration of response was 13 months. All patients showed alopecia and moderate leukopenia; 13 experienced moderate gastrointestinal toxicity; there was 1 mild case of anemia and 1 case of moderate hemorrhagic cystitis. This study suggests that the combination of VP 16-213 and cyclophosphamide is a well-tolerated and effective treatment in advanced breast cancer patients with liver metastases.

Administration, Oral↗

PubMed1990

LH and FSH secretion and responses to GnRH and TRH in patients with clinically functionless pituitary adenomas.

Serum concentrations of LH and FSH and their response to the separate administration of GnRH (100 micrograms i.v.) and TRH (200 micrograms i.v.) have been studied preoperatively in 12 patients with a clinically functionless pituitary adenoma, of whom nine (3F: 6M) were found to secrete gonadotrophins in vitro. In three patients with a gonadotrophin-secreting adenoma (GSA) the pulsatile release of LH and FSH was also assessed preoperatively. An elevated serum FSH was recorded in six of nine patients with a GSA, and was subnormal in one, whilst an elevated LH was recorded in only two and was subnormal in six. A doubling of LH occurred in only four of the nine patients after GnRH and in three of six after TRH. None of the three patients with a non-GSA was shown to have an aberrant response to GnRH or TRH. In patients with a GSA, pulsatile release of LH and FSH was usually asynchronous and neither hormone demonstrated any regular harmonic pattern. These data show that in patients with a GSA the serum FSH level is usually elevated but this is not invariable, and the LH may well be low. Pathological responses of LH are frequently found following the administration of either GnRH or TRH and these stimulation tests should be performed separately in patients presenting with a clinically 'non-functioning' pituitary tumour to assist in the preoperative diagnosis. The absence of normal LH and FSH pulsing also appears to be a feature of GS adenomas, and suggests that tumorous gonadotrophin secretion is not under physiological control by hypothalamic GnRH.

Adenoma↗

PubMed1990

Deficient collagen-induced activation in the newborn platelet.

We have investigated the impaired secretion response of neonatal platelets. We compared the response of washed neonatal and adult platelets to thrombin and collagen, and to specific activators of calcium flux (inositol trisphosphate) and protein kinase C activation (oleoyl-acetyl glycerol). Neonatal platelets show no impairment of aggregation, secretion of [14C]serotonin or phosphorylation of specific intracellular proteins in response to thrombin, inositol trisphosphate, or oleoyl-acetyl glycerol. However, neonatal platelets have a markedly decreased response to collagen. To further evaluate this deficient response, we examined specific aspects of the collagen activation pathway. Collagen-platelet interaction as measured by adhesion of platelets to collagen-coated dishes showed no difference in adhesion of neonatal platelets compared to adult controls (20.1 +/- 11.6 versus 18.6 +/- 9.3%). The presence of GPIa/IIa, a Mg2(+)-dependent collagen receptor, was evaluated by flow cytometric analysis of binding of fluorescein-tagged monoclonal antibody, 6F1 (directed against GPIa/IIa). There was no difference either in the percent of platelets that bound antibody (80 versus 81%) or in the mean fluorescence intensity of the adult and neonatal samples. Phosphoinositide hydrolysis was decreased in neonatal platelets in response to collagen but normal in response to thrombin. Neonatal platelets released more arachidonic acid than adult platelets in response to thrombin (29.5 +/- 3.2 versus 19.6 +/- 1.8%) but less than adult platelets in response to 10 micrograms/mL collagen (3.2 +/- 1.1 versus 9.3 +/- 3.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

The functioning and well-being of depressed patients. Results from the Medical Outcomes Study.

We describe the functioning and well-being of patients with depression, relative to patients with chronic medical conditions or no chronic conditions. Data are from 11,242 outpatients in three health care provision systems in three US sites. Patients with either current depressive disorder or depressive symptoms in the absence of disorder tended to have worse physical, social, and role functioning, worse perceived current health, and greater bodily pain than did patients with no chronic conditions. The poor functioning uniquely associated with depressive symptoms, with or without depressive disorder, was comparable with or worse than that uniquely associated with eight major chronic medical conditions. For example, the unique association of days in bed with depressive symptoms was significantly greater than the comparable association with hypertension, diabetes, and arthritis. Depression and chronic medical conditions had unique and additive effects on patient functioning.

Adult↗

PubMed1989

Lifetime evidence for a weak lowest electronic transition in adenosine.

The fluorescence decay of adenosine in 1:1 glycol/water glass has been determined at 77K using narrow pulse (700 ps) laser excitation at 290 nm and fluorescence detection with a scanned narrow-gate (100 ps) fast sampler together with digital averaging. Data analysis by re-iterative non-linear least squares convolution shows the decay is best represented by the bi-exponential form I(t) = 0.59exp - t/1.2ns + 0.41 exp - t/7.0ns. This leads to intrinsic radiative lifetimes of 150 ns and 220 ns respectively and a combined oscillator strength of 1.5 x 10(-2). Compared with the overall oscillator strength of 0.29 for the entire first absorption band of adenosine this indicates that transitions to and from the lowest-lying state in this band are quite forbidden. This is not accounted for by current theoretical considerations.

Adenosine↗

PubMed1989

Lymphocyte function in major depression.

Immunologic function as measured by lymphocyte response to phytohemagglutinin (PHA) mitogen was evaluated in 8 psychiatric inpatients. All were less than 45 years of age and had a DSM-III diagnosis of major depression. When patient's immunologic responses were compared with healthy age- and sex-matched controls, a significant increase in PHA mitogen stimulation was observed in the depressed group. Further, a significantly greater variance in PHA response was observed in the patients compared with controls. The literature on depression and immunity is reviewed and the clinical implications of our findings are discussed.

Adult↗

PubMed1988

Phosphorescence of adenosine and poly(riboadenylic acid). Evidence for dual emissions and n pi states.

Phosphorescence from the 9-adenylyl group in the form of microcrystalline powders of adenosine films of poly(riboadenylic acid) (poly(rA)) in hyaluronic acid has been studied at 77 K. For adenosine, clearly resolved vibronic structure consists of two progressions, A and B, with delta vA = 1363 cm-1 and delta vB = 1575 cm-1, correlated with in-plane C5-N7 and in-plane C4-C5 stretch, respectively. The relative strength of the progressions varies with excitation wavelength and this, together with the absence of a common origin, indicates the existence of two independent emitting states with 0-0' levels separated by either 300 or 1000 cm-1. Two different excitation spectra are observed lying below the normal (pi pi*) adsorption and one is assigned as a previously undetected 1(n pi*) transition. For poly(rA) films the emission band envelope is identical with that of adenosine but the vibronic structure is lost. Only one excitation peak is observed at 32.9 X 10(3) cm-1, identical with one of the adenosine spectra. The second adenosine excitation spectrum probably represents an intermolecular charge transfer transition. Comparison is made with the predictions of six semi-empirical MO calculations.

Adenosine↗

PubMed1988

Synchrotron-excited time-resolved fluorescence spectroscopy of adenosine, protonated adenosine and 6N,6N-dimethyladenosine in aqueous solution at room temperature.

The fluorescence behavior of adenosine in neutral solution has been studied by time-resolved spectroscopy using synchrotron excitation and time-correlated single photon counting, and by decay time measurements. Three emissions have been identified and correlated with three excitation spectra. The assignment of these transitions has been made by comparison with similar measurements on 6N,6N-dimethyladenosine (6DMA), and on adenosine in acid solution (ADO H+). It is proposed that two of the transitions of adenosine which correlate with 6DMA originate from coplanar and orthogonal rotational conformers of the amino group. The other transition, correlating with ADO H+ may originate either from the 3H-imino tautomer, or from a differently solvated rotational conformer.

Adenosine↗

PubMed1988

Plasma cortisol and natural killer cell activity during bereavement.

Natural killer cell (NK) activity, which is important in the defense against tumors and viral infections, is reduced in women undergoing conjugal bereavement. The relationship between NK activity and plasma cortisol was investigated in three groups of subjects: women who were anticipating the death of their husbands, women whose husbands had recently died, and controls. Bereaved women showed reduced NK activity and increased plasma cortisol levels as compared to controls. Anticipatory bereaved women also showed significant reductions in NK activity, but had levels of plasma cortisol comparable to those of controls. The reduction of NK activity during anticipatory and actual bereavement cannot be explained solely on the basis of increased cortisol secretion.

Female↗

PubMed1988

Ovine estrus synchronization and superovulation using norgestomet B and follicle stimulating hormone-pituitary.

Finewooled Rambouillet range ewes were used in a study to determine the feasibility of using a progesterone ear implant to synchronize estrus. In addition, some of the ewes were further treated with injections of follicle stimulating hormone-pituitary (FSH-P) to induce superovulation. Five days following estrus detection and breeding, FSH-P-treated ewes were laparotomized and surgically flushed to recover embryos. The number of corpora lutea (CL), the total number of embryos and the number of transferable embryos recovered were recorded along with the number and size of follicles present on both ovaries. Ewes synchronized as recipients were laparotomized for surgical transfer of embryos 5 d following estrus. The number of CL and follicles were recorded. Response to superovulation by FSH-P did not differ (P>0.05) between age groups of ewes when the number of CL present was counted. However, the total number of embryos flushed and good embryos was lower (P<0.05) among the oldest (7 yr) ewes. The number of follicles present showed little variation between age groups. Recipient ewes (No FSH-P) were similar in the number of CL with 6-yr-old ewes, having fewer (P>0.05) CL, than 3-, 4- or 7-yr-old ewes. Only slight variation was boserved in the number of follicles in recipient ewes. Among donor ewes receiving FSH-P in addition to Synchro-Mate B, 71% were detected in estrus within 48 h of implant removal vs 55% of the recipients.

Journal Article↗

PubMed1988

Sequence-dependent emission from stacked forms of ApC and CpA. Evidence for stacked base ('dimer') absorption and left-handed stacked conformation.

The corrected and normalised emission spectrum, quantum yield and emission anisotropy are reported for partially stacked adenylyl-3',5'-cytidine (ApC) excited at 266 nm and are compared with cytidylyl-3',5'-adenosine (CpA). Utilizing characteristics determined independently for adenosine and cytidine-5'-monophosphate (CMP), the concurrent self-consistent resolution of emission spectrum and emission anisotropy has been carried out in two ways; first completely empirically as for CpA and second on the basis of a simple stacking model, with concordant results. The total emission spectrum of ApC is resolved into (i) components characteristic of the two monomers and (ii) a red-shifted complex emission. The complex emission spectrum, which is much stronger than from CpA and is complementary to it in bandshape, can also be satisfactorily described by the same components. The dimeric (A, C) system can exist in at least two luminescent stacked forms, proportions of which are determined by the overall stacked fraction and the population within this fraction of the various stacked conformers. The relation between the ratios of the components and the fractional absorption of the stacked forms indicates that the low-energy component is a (hetero-) dimer emission while the high energy component appears to be a true exciplex (hetero-excimer). Comparison with the circular dichroism and NMR literature shows a satisfactory semi-quantitative correlation with the hypothesis that the low energy (hetero-) dimer emission originates from a left-handed stacked conformation Mbb, while the higher energy hetero-excimer originates from the predominant right-handed stacked conformation Pba.

Cytidine Monophosphate↗

PubMed1988

Long-term effects of a gonadotrophin-releasing hormone agonist ([D-Ser(But)6]GnRH(1-9)nonapeptide-ethylamide) on gonadotrophin secretion from human pituitary gonadotroph cell adenomas in vitro.

We have studied the effects of TRH and native gonadotrophin-releasing hormone (GnRH), and of a GnRH agonist (Buserelin; [D-Ser(But )6]GnRH(1-9) nonapeptide-ethylamide), on LH, FSH, alpha subunit and LH-beta subunit secretion from three human gonadotrophin-secreting pituitary adenomas in dispersed cell culture. During a 24 h study, treatment with 276 nmol TRH/l resulted in a significant (P less than 0.05) stimulated release of FSH and alpha subunit from all three adenomas, and LH from the two adenomas secreting detectable concentrations of this glycoprotein; treatment with 85 nmol GnRH/l significantly (P less than 0.05) stimulated the release of alpha subunit from all three, but FSH from only two and LH from only one adenoma. During a long-term 28-day study, basal FSH and alpha subunit concentrations were maintained, but secretion of LH, and LH-beta (detectable from one tumour only), declined with time from two of the three adenomas. Addition of Buserelin to the cultures resulted in the continuous (P less than 0.05) stimulation of alpha subunit secretion from all three adenomas, and of LH and FSH from two, whilst a transient stimulatory effect on LH and FSH secretion was seen from a third adenoma, with subsequent secretion rates declining towards control values. These data show that human gonadotrophin-secreting adenomas demonstrate variable stimulatory responses to hypothalamic TRH and GnRH, and that during chronic treatment with a GnRH agonist the anticipated desensitizing effect of the drug was not observed in two out of the three adenomas studied. The mechanisms for this is not clear, but such drugs are unlikely to be of therapeutic value in the management of gonadotrophin-secreting tumours. The data also suggest that GnRH and GnRH agonists have a differential effect on the in-vitro release of intact gonadotrophins and the common alpha subunit.

Adenoma↗

PubMed1987

Monoclonal antibodies to bovine growth hormone potentiate effects of the hormone on somatomedin C levels and growth of hypophysectomized rats.

Bovine growth hormone (50 micrograms/day) elevated somatomedin C levels in plasma of hypophysectomized rats: the effect was seen 12 h after the first injection and was sustained throughout a 7-day treatment period. When monoclonal antibodies to bovine growth hormone were administered with the hormone the stimulation of somatomedin C levels was markedly enhanced, as were effects on body weight. Each one of a panel of 7 monoclonal antibodies potentiated the actions of the hormone on growth and somatomedin C levels, though the extent and pattern of potentiation varied considerably from one antibody to another. Effects on growth and somatomedin C levels correlated fairly well, though there were some discrepancies.

Animals↗

PubMed1987

Impaired natural killer cell activity during bereavement.

Natural killer (NK) cell activity, a component of the immune surveillance system, was compared in women whose husbands had recently died with that found in age-matched women who had not experienced recent adverse life events. Bereaved women had significantly lower NK activity than women whose husbands were healthy. In a second study, depressive symptoms and NK activity were measured longitudinally in women before and after the death of their husbands. Our results suggest that depressive symptoms, not merely the death of the spouse, are related to a reduction in NK activity during bereavement.

Bereavement↗

PubMed1987

Life events, depressive symptoms, and immune function.

Because both bereavement and depression have been associated with impaired immune responses, the authors studied two indicators of immune function, natural killer (NK) cell activity and measures of T cell subpopulations, in 37 women who differed in the magnitude of recent life events. Women who had experienced major life changes had lower NK cell activity than women who had few changes. Severity of depressive symptoms in these women was associated with an impairment of NK cell activity, an absolute loss of suppressor/cytotoxic cells, and an increase in the ratio of T helper to T suppressor/cytotoxic cells.

Adult↗

PubMed1987

Long-term in-vitro maintenance of growth hormone secretion from human somatotrophinomas with cortisol, and its effects on growth hormone-releasing factor.

The effect of cortisol (206 nmol/l) on GH secretion from enzymatically dispersed human somatotrophinoma cells in long-term culture was studied using adenomas from 13 patients with acromegaly. Basal GH secretion from cultures of three out of five tumours measured during periods of 4 hours declined to less than 10 mu u. GH/culture within 21 days. Secretion from two other tumours measured during 24 h also declined but GH concentrations were still readily detectable (greater than 100 mu u./culture) by 28 or 58 days after cell dispersal. The decline in GH secretion was reversed in all seven tumours when cultures were maintained in cortisol-supplemented medium (CM), 4-h secretion rates being increased or retained at greater than or equal to 100 mu u./culture for as long as the studies were continued (range 18-291 days), and 24-h secretion rates at greater than 1000 mu u./culture (range 28-58 days). GH secretion and content from cultures of two additional somatotrophinomas were increased by treatment with cortisol for 5 or 9 days but there was no concomitant effect on cell number. During long-term maintenance of cultures in CM (range 5-40 days), cortisol partially or completely blocked the 4-h GH response to a test dose of GH-releasing factor (GRF) (20 nmol/l) in five out of six tumours, and to a dose range of GRF (0.01-20 nmol/l) in two of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗