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Biomedical subjects

E Allen

Publications and source records attributed to E Allen.

At least 73 records · Page 4Linked to original sources
PubMed1994

The contingent negative variation in positive and negative types of schizophrenia.

The authors analyzed the contingent negative variations of 20 medicated patients with schizophrenia diagnosed according to DSM-III-R and 20 age- and sex-matched normal comparison subjects. For the patients with schizophrenia, there were significant correlations between contingent negative variation amplitude and two items on the Scale for the Assessment of Negative Symptoms (affective flattening and avolition-apathy) and the total score on this scale. These findings have implications regarding the underlying pathology of negative and positive symptoms of schizophrenia.

Adult↗
PubMed1994

Tuberculosis in young adults and the elderly. A prospective comparison study.

OBJECTIVES: To compare the clinical, bacteriologic, and radiologic features of pulmonary and pleural tuberculosis in young adults and the elderly and determine if any differences exist between both groups. DESIGN: Prospective recruitment of all patients diagnosed as having pulmonary and pleural tuberculosis in British Columbia, Canada. SETTING: A population-based sample from a provincial control program TB registry. PATIENTS: A total of 218 consecutive patients whose conditions were diagnosed between January 1990 and May 1991. We excluded 15 HIV-positive patients whose conditions were diagnosed during this study. INTERVENTION: Standardized data collection of symptoms, bacteriology, and review of radiology by two readers blind to the clinical and epidemiologic data. MAIN RESULTS: There were 142 young adult patients and 76 elderly patients. The young adults had a mean age of 41.2 years and the elderly group had a mean age of 75 years of age. Fever (p = 0.002) and night sweats (p = 0.02) were more common in young adults. In culture-proven disease, hemoptysis, fever, and cough were more common in young adult (p = 0.03, 0.02, and 0.01, respectively). There was no difference in the duration of symptoms between the two groups. The odds ratio for cancers other than lung cancer, 3.98 (confidence interval, 1.49, 10.65) in the elderly group was the only significant risk factor to differ between the two groups. Skin test responses to 5TU PPD were positive in 86.2 percent of young adults and 67.6 percent of elderly patients tested (p = 0.03). A total of 79.6 percent of young adults and 88.15 percent of the elderly patients (not significant) were culture positive. Comparison of radiologic findings in young adults vs elderly patients showed no significant differences apart from those with miliary TB 0.7 percent vs 6.7 percent (p = 0.04). CONCLUSIONS: In this population-based study, young adults were more likely to have hemoptysis, fever, and cough and to have a positive PPD response. Cancer was significantly associated as a risk factor in the older age group. There was no difference in bacteriologically proven disease or radiologic findings between the two groups, apart from the more common occurrence of miliary TB in the elderly.

Adult↗
PubMed1994

Efficacy of electroconvulsive therapy after propofol and methohexital anesthesia.

Fifty-eight patients with major depression were randomly assigned to receive a hypnotic dose of either propofol or methohexital for their complete treatment series of electroconvulsive therapy (ECT). As expected, seizure duration was significantly shorter with propofol than with methohexital anesthesia. Both groups recovered from their depression at the same rate. There was a significant improvement in the Hamilton Rating Scale for Depression scores between the first and last ECT session. However, this was independent of the choice of propofol or methohexital as the anesthetic. This study supports previous reports that seizure duration does not influence recovery from depression.

Adolescent↗
PubMed1994

Contrast agents in neuroimaging.

Until there is total elimination of adverse reactions and side effects with contrast agents, there will continue to be a need for improvement. The ideal contrast agent should be efficacious, safe, water soluble, with chemical and heat stability, biologically inert, with low viscosity, with osmolality the same as human serum, with selective excretion by the kidneys, and inexpensive.

Adult↗
PubMed1993

Neutrophils, differentiated macrophages, and monocyte/macrophage antigen presenting cells infiltrate murine epidermis after UV injury.

We asked whether, as in humans, a population of antigen-presenting macrophages infiltrates the epidermis of ultraviolet (UV)-exposed BALB/c mice. Using three-color flow cytometry on cell suspensions plus in situ immunofluorescence microscopy, the phenotype of normal Langerhans cells was class II major histocompatibility complex (MHC+), CD11b+, NLDC-145+, BM8+ CD45+ and homogeneous. By contrast, in epidermal cells harvested 3 d following UV (UV-EC), there were two subsets of class II MHC+ cells: 1) class II MHChi CD11b+, and 2) class II MHClo CD11b-. Neither expressed the Langerhans cell markers BM8 and NLDC-145. In addition, there were two major populations of class II MHC- CD11b+ cells; half of these expressed the GR-1 neutrophil marker. Langerhans and dendritic epidermal T cells were markedly reduced after UV injury. By electron microscopy, immunomagnetic bead-purified CD11b+ cells in UV-EC were comprised of neutrophils, differentiated macrophages, and mononuclear cells with prominent lysosomes, but no Birbeck granules; the class II MHC+ subset resembled a monocytic cell in between differentiated macrophages and indeterminate dendritic cells. Functionally, immediately following in vivo UV exposure, the allogeneic antigen-presenting cell capacity of UV-EC was reduced to 21 +/- 6% of control epidermal cells (C-EC); by 3 d, antigen-presenting cell activity of UV-EC had recovered to 59 +/- 11% of C-EC, although at this time NLDC-145+ Langerhans cells had reached their lowest number. The recovered antigen-presenting cell activity was critically dependent upon the class II MHChiCD11b+ cells. Sensitization of BALB/c mice through skin that contained these antigen-presenting cells (3 d after UV) resulted in tolerance to dinitrofluorobenzene. By contrast, sensitization through UV-exposed skin immediately after the exposure resulted in unresponsiveness without tolerance, demonstrating temporal association of tolerance with leukocytic infiltration. In summary, murine epidermis responds to an acute UV injury in vivo with an initial abrogation of antigen-presenting activity followed by epidermal infiltration with neutrophils, differentiated macrophages, and monocytic antigen-presenting cells that are distinct from Langerhans cells with regard to expression of Langerhans cell markers and ultrastructure.

Animals↗
PubMed1993

Therapeutic parenting--a program for home care.

There is evidence that inadequate parenting in early childhood, combined with socioeconomic risk factors, can contribute to intellectual deficits, character disorders, and antisocial behaviors in children. Early intervention home care services can circumvent these problems.

Child Abuse↗
PubMed1992

Application of an organic solvent extraction to the determination of catechol-O-methyltransferase activity by high-performance liquid chromatography in human mononuclear cells.

We report here a method for measuring mononuclear cell catechol-O-methyltransferase (COMT) activity which is ideally adapted to clinical studies. The method measures the O-methylation of dopamine to 3-methoxytyramine and 4-methoxy-3-hydroxyphenethylamine. Whole mononuclear cell sonicate is incubated with saturating concentrations of dopamine, S-adenosyl-L-methionine and magnesium chloride in sodium-potassium phosphate buffer at pH 7.3. An organic solvent extraction using ethyl acetate is then used for product separation, followed by high-performance liquid chromatography with electrochemical detection for product separation and quantification. This method allows both O-methylated products, 3-methoxytyramine and 4-methoxy-3-hydroxyphenethylamine, to be isolated and quantified separately. The apparent Michaelis constants for dopamine and S-adenosyl-L-methionine using this method are similar to values reported previously (0.51 and 14 microM, respectively). The optimal concentration of magnesium chloride is eight to ten times higher than previously reported. No endogenous inhibitors were apparent using this assay. The within-day coefficient of variation using this method is 7% when measuring 3-methoxytyramine and 5% when measuring 4-methoxy-3-hydroxyphenethylamine. The between-day coefficient of variation is 11%. Mononuclear cell COMT activity can be detected using protein concentrations as low as 0.75 mg/ml, corresponding to 2-3 ml of whole blood. The small amount of blood required per sample allows multiple sample analysis from a single patient, including infants.

Adult↗
PubMed1991

Establishment and characterization of a human carcinoid in nude mice and effect of various agents on tumor growth.

The authors have established a long-term tissue culture cell line (BON) derived from a metastatic human carcinoid tumor of the pancreas. The cells have been in continuous passage for 46 months. Tissue culture cells produce tumors in a dose-dependent fashion after SC inoculation of cell suspensions in athymic nude mice. BON tumors, grown in nude mice, are histologically identical to the original tumor; they possess gastrin and somatostatin receptors, synthesize serotonin and chromogranin A, and have a doubling time of approximately 13 days. The antiproliferative effects of the long-acting somatostatin analogue, SMS 201-995 (300 micrograms/kg, t.i.d.), and 2% alpha-difluoromethylornithine on BON xenografts in nude mice were examined. Tumor size was significantly decreased by day 14 of treatment with either agent and at all points of analysis thereafter until the animals were killed (day 33). In addition, tumor weight, DNA, RNA, and protein contents were significantly decreased in treated mice compared with controls. Establishment of this human carcinoid xenograft line, BON, provides an excellent model to study further the biological behavior of carcinoid tumors and the in vivo effect of chemotherapeutic agents on tumor growth.

Animals↗
PubMed1990

Serum levels of pregnancy-associated endometrial alpha 2-globulin (alpha 2-PEG), a glycosylated beta-lactoglobulin homologue, in successful and unsuccessful assisted conception.

Pregnancy-associated endometrial alpha 2-globulin (alpha 2-PEG) is the major secretory protein of the endometrium in the late luteal phase. Serum levels were measured during the implantation period in successful and unsuccessful cycles of assisted conception. The effects of two different treatment regimens were also compared. All patients who underwent ovulation induction therapy showed an endometrial response as measured by a rise in serum levels of alpha 2-PEG. This rise was the same regardless of either implantation or the method of ovulation induction used. Higher levels were seen at oocyte recovery in those cycles treated with clomiphene citrate and may reflect a disordered endometrial response involving a direct effect of the drug on the endometrium. This may explain the difference in success rates in assisted conception when an alternative treatment initially involving down-regulation of endogenous gonadotrophin activity and subsequent administration of gonadotrophins is used. The rise in serum levels seen in pregnancy did not differ statistically according to whether the pregnancy progressed normally or subsequently aborted. Considerably reduced alpha 2-PEG production by the endometrium was identified in one patient who subsequently aborted. The measurement of serum levels of alpha 2-PEG during the implantation phase is unlikely to provide a clinical tool either for early detection of pregnancy or as a prognostic factor of successful implantation.

Abortion, Spontaneous↗
PubMed1990

Phenotype, ultrastructure, and function of CD1+DR+ epidermal cells that express CD36 (OKM5) in cutaneous T-cell lymphoma.

This study investigated the phenotype and function of different antigen-presenting cells (APC) present within the epidermis of patients with cutaneous T-cell lymphoma (CTCL). Involved epidermis of CTCL compared with uninvolved was found to contain increased numbers of CD1+DR+ APC. This population was heterogeneous and comprised both leucocytes of a novel CD1+DR+CD36 (OKM5)+ phenotype and CD1+DR+CD36- indeterminate/Langerhans cells. The CD1+DR+CD36+ leucocytes did not express TcR-1, CD5, CD15, or CD22, and only a minor population expressed CD11, demonstrating that they were neither T nor B cells, and did not belong to the major CD11+ (OKM1+) blood monocyte population. Electron microscopy of purified CD36+ lesional epidermal cells (EC) demonstrated that they lacked Birbeck granules found on CD1(+)-selected Langerhans cells, and most cells exhibited features of indeterminate cells or macrophages. The capacity of EC from involved epidermis to present alloantigens was found to be increased relative to uninvolved epidermis in all patients tested, and this capacity was critically dependent upon the presence of CD45+DR+ bone marrow-derived cells but not on the presence of CD45-DR+ keratinocytes. Positive selection using MoAb against CD1 and CD36 demonstrated that both cell populations exhibited the capacity to stimulate T cells. The results indicate that a novel antigen-presenting cell population with a unique phenotype is present within involved skin of patients with mycosis fungoides. These cells express CD36 in addition to CD1 and have an ultrastructural appearance consistent with a dendritic antigen-presenting cell derivation.

Antibodies, Monoclonal↗
PubMed1990

Effect of total jejunoileal denervation on fat-stimulated release of peptide YY and cholecystokinin.

We have investigated the effect of total denervation of the jejunoileum (JDNv) on stimulated release of peptide YY (PYY) and cholecystokinin-33/39 in five dogs prepared with chronic gastric and duodenal cannulas. JDNv was performed by stripping the adventitia from the superior mesenteric artery and vein, transecting the small bowel mesentery, and division (with reanastomosis) of the small bowel at the ligament of Treitz and ileocecal junctio. Introduodenal corn oil (3 ml/kg/hr) was given before JDNv and 1 and 2 months after JDNv. Intravenous bombesin (400 pmol/kg/hr) was given (on nonconsecutive days) before JDNv and 1 month after JDNv. Plasma PYY and cholecystokinin levels were measured by specific radioimmunoassay. Release of PYY was enhanced after JDNv. The integrated release of PYY (ng.[0 to 60 min]/ml) after intraduodenal corn oil was as follows: before JDNv, 4.1 +/- 1.2; 1 month after JDNv, 16.0 +/- 2.7; and 2 months after JDNv, 10.3 +/- 2.2. Similar results were noted with intravenous bombesin (3.7 +/- 0.9 [before JDNv] vs 12.0 +/- 0.7 [1 month after JDNv]). Corn oil-stimulated release of cholecystokinin was abolished after JDNv (before JDNv 2.2 +/- 1.1; 1 month after JDNv, 0.6 +/- 0.3; and 2 months after JDNv, 0.4 +/- 0.6). Basal plasma levels of PYY and cholecystokinin were not affected by JDNv. We conclude that JDNv enhances PYY and abolished cholecystokinin release, which provides evidence for different mechanisms of neural control.

Animals↗
PubMed1989

Evaluation of a serologic marker, CA19-9, in the diagnosis of pancreatic cancer.

STUDY OBJECTIVE: To determine the utility of the serologic marker CA19-9 in the diagnosis of pancreatic cancer in patients suspected of having a pancreatic disorder. DESIGN: Blinded study of frozen pedigreed serum samples collected at time of diagnostic evaluation with follow-up review at a mean of 8 years. SETTING: A general university teaching hospital serving both primary and referral patient populations. MEASUREMENTS AND MAIN RESULTS: Sera collected prospectively from 1978 to 1980 from 261 patients undergoing imaging studies of the pancreas (ultrasound, computed tomography, endoscopic retrograde cholangiopancreatography) for a variety of symptoms were assayed for CA19-9 levels, and the results were compared with earlier determinations of other potential markers for pancreatic cancer. In 54 patients ultimately shown to have pancreatic cancer, the CA19-9 assay showed a sensitivity of 70% with a median value of 349 u/mL (normal less than 70 u/mL) and range, 7.3 to 2,859,964 u/mL, whereas specificity of the marker in this population was 87%. The positive predictive value was 59%, and the negative predictive value was 92%. Results of CA19-9 testing in the small group of patients with definitive staging information showed no difference in sensitivity between patients with local/regional disease (n = 6) and those with distant metastases (n = 14), 50% compared with 71% (P = 0.613). CONCLUSION: CA19-9 was found to be a more sensitive and specific marker of pancreatic cancer than other serologic markers and should be a useful test in the patient with suspected pancreatic disease.

Adenocarcinoma↗
PubMed1989

Craniopagus parasiticus. Everard Home's Two-Headed Boy of Bengal and some other cases.

Craniopagus parasiticus, or épicome, is a rare teratological type, of which only six cases have been recorded in the medical literature. It differs from craniopagus conjoined twins in that the body and limbs of the parasitic twin are underdeveloped, leaving in some cases only a parasitic head, inserted on the crown of the autositic twin. The first case of this malformation was Everard Home's famous Twin-Headed Boy of Bengal, whose skull is preserved at the Hunterian Museum. In this historical review, Home's case is presented in some detail, and the later cases are used to explain further some of its particulars.

Abnormalities, Severe Teratoid↗
PubMed1989

Thyrotropin (TSH)-releasing hormone-stimulated TSH release and TSH concentration in the guinea pig pituitary, as determined by a heterologous radioimmunoassay.

Little is known regarding how the guinea pig (GP) compares with the rat in terms of TSH economy. To develop a heterologous RIA for GP TSH, rabbits were injected with GP TSH. In one rabbit (anti-gpTSH-8), antibodies that bound 125I-labeled bovine (b) TSH and rat (r) TSH but not 125I-labeled bLH or rPRL were generated. The binding of anti-gpTSH-8 to [125I]bTSH was inhibited in a parallel manner by bTSH over a range of 0.047-5.42 ng, rTSH over a range of 0.24-25 ng, and dilutions of GP pituitary extracts. This system, with bTSH as the standard, was employed as the basis for a heterologous TSH RIA (GP TSH RIA). The cross-reactions of rTSH and bLH in the GP TSH RIA were 45% and 7%, respectively. Rat and bovine FSH, GH, and PRL had little or no cross-reaction. GP pituitaries were incubated in vitro and dosed with LHRH and TRH. The GP TSH RIA detected an 11-fold increase in TSH in the medium in response to TRH and no change in immunoreactivity in response to LHRH. In contrast, a RIA for bLH detected a 25-fold increase in LH in the medium in response to LHRH and no increase in response to TRH. The TSH content in GP pituitaries was significantly lower than that in the rat (GP, 16.8 +/- 1.6 ng/mg; rat, 80.3 +/- 6.2 ng/mg; P less than 0.05) as were serum TSH concentrations (GP, 0.8 +/- 0.4 ng/ml; rat, 4.5 +/- 1.1 ng/ml; P less than 0.05). Thyroid hormone administration (T4 Rx) in both GP and rat produced a significant reduction in pituitary TSH content (GP control, 4.8 +/- 0.4 ng/mg; T4 Rx, 2.1 ng/mg; P less than 0.05; rat control, 52.4 +/- 4.0 ng/mg; T4 Rx, 20.5 +/- 1.6 ng/mg; P less than 0.05) and TSH release (GP control, 9.4 +/- 2.3 ng/ml; T4 Rx, 4.3 +/- 1.5 ng/ml; P less than 0.05; rat control, 357 +/- 81 ng/ml; T4 Rx, 133 +/- 27 ng/ml; P less than 0.05) from incubated hemipituitaries. Thyroidectomy in the rat was associated with a decrease in pituitary TSH content, but no change in pituitary content was found in thyroidectomized GPs. These studies demonstrate the feasibility of estimating GP TSH with a heterologous RIA that employs polyvalent antiserum against GP TSH as the first antibody and bTSH as the tracer and standard.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Cerebral arteriovenous oxygen difference as an estimate of cerebral blood flow in comatose patients.

The hypothesis that cerebral arteriovenous difference of oxygen content (AVDO2) can be used to predict cerebral blood flow (CBF) was tested in patients who were comatose due to head injury, subarachnoid hemorrhage, or cerebrovascular disease. In 51 patients CBF was measured daily for 3 to 5 days, and in 49 patients CBF was measured every 8 hours for 5 to 10 days after injury. In the latter group of patients, when a low CBF (less than or equal to 0.2 ml/gm/min) or an increased level of cerebral lactate production (CMRL) (less than or equal to -0.06 mumol/gm/min) was encountered, therapy was instituted to increase CBF, and measurements of CBF, AVDO2, and arteriovenous difference of lactate content (AVDL) were repeated. When data from all patients were analyzed, including those with cerebral ischemia and those without, AVDO2 had only a modest correlation with CBF (r = -0.24 in 578 measurements, p less than 0.01). When patients with ischemia, indicated by an increased CMRL, were excluded from the analysis, CBF and AVDO2 had a much improved correlation (r = -0.74 in 313 measurements, p less than 0.01). Most patients with a very low CBF would have been misclassified as having a normal or increased CBF based on the AVDO2 alone. However, when measurements of AVDO2 were supplemented with AVDL, four distinct CBF patterns could be distinguished. Patients with an ischemia/infarction pattern typically had a lactate-oxygen index (LOI = -AVDL/AVDO2) of 0.08 or greater and a variable AVDO2. The three nonischemic CBF patterns had an LOI of less than 0.08, and could be classified according to the AVDO2. Patients with a normal CBF (mean 0.42 +/- 0.12 ml/gm/min) had an AVDO2 between 1.3 and 3.0 mumol/ml. A CBF pattern of hyperemia (mean 0.53 +/- 0.18 ml/gm/min) was characterized by an AVDO2 of less than 1.3 mumol/ml. A compensated hypoperfusion CBF pattern (mean 0.23 +/- 0.07 ml/gm/min) was identified by an AVDO2 of more than 3.0 mumol/min. These studies suggest that reliable estimates of CBF may be made from AVDO2 and AVDL measurements, which can be easily obtained in the intensive care unit.

Arteries↗