The cholinergic deficit coincides with Abeta deposition at the earliest histopathologic stages of Alzheimer disease.

Effective therapeutic intervention in Alzheimer disease (AD) will be most effective if it is directed at early events in the pathogenic sequence. The cholinergic deficit may be such an early event. In the present study, the brains of 26 subjects who had no history of cognitive loss and who were in early histopathologic stages of AD (average Braak stage less than II) were examined at autopsy to determine whether a cortical cholinergic decrement was associated with Abeta concentration or deposition. In the superior frontal and inferior temporal gyri, the choline acetyltransferase (ChAT) activity of plaque-containing cases was significantly decreased (p < 0.05, unpaired, two-tailed t-tests), measuring 70.9% and 79.5%, respectively, relative to plaque-free cases. In the inferior temporal gyrus, Spearman's rank correlation analysis showed that ChAT activity had a significant inverse correlation with Abeta concentration (p = 0.075; r = -0.3552). The results indicate that the cholinergic deficit is established at an early histopathologic stage of AD, before the onset of clinical symptoms.

Characterization of the systemic disease and ocular signs induced by experimental infection with Chlamydia psittaci in cats.

In addition to the commonly reported ocular signs, Chlamydia psittaci infection of kittens resulted in fever, lethargy, lameness and reduction in weight gain following ocular instillation of virulent organisms. The appearance of these systemic signs was late with respect to the appearance of ocular symptoms and occurred simultaneously with increasing levels of chlamydia-specific IgG. Measurement of acute phase reactants and IL-6 in plasma indicated that both became elevated concurrent with or slightly after the appearance of fever and remained elevated after the fever began to resolve. Preliminary data also indicated that infectious C. psittaci was present in the blood stream during this time period. The results of ocular instillation of three different levels of C. psittaci (10(3.8), 10(2.8) and 10(1.5) TCID50) indicated that the frequency of infection and the severity of ocular signs were diminished in the group receiving the lowest dose. However, the magnitude of systemic disease was similar in all animals which exhibited clinical signs, irrespective of the dose administered. The immune response to infection included elementary body (EB)-specific lymphocyte proliferation as well as the development of EB-specific IgG and IgM antibodies. The predominant antibody response was to a 45 kDa protein, the major outer membrane protein (MOMP), lipopolysaccharide (LPS), a 58 kDa doublet and 32 and 16-19 kDa proteins.

Comparison of the primary signs induced by experimental exposure to either a pneumotrophic or a 'limping' strain of feline calicivirus.

Two strains of feline calicivirus, one reportedly pneumotrophic (FPV 255) and the other associated with a limping syndrome (2280) were compared with respect to the signs induced in kittens after oronasal exposure. Neither strain induced severe upper respiratory symptoms, and both caused oral ulcers and lameness. However oral ulcers were more prevalent, and lameness and depression were more pronounced in the kittens which received strain 2280. Kittens which exhibited lameness also had elevated blood levels of alpha 1-acid glycoprotein. A decline in lymphocyte count was noted only in kittens which received strain 2280. These data demonstrate that despite reported antigenic and genetic differences between these strains, no distinct differences in pathogenicity could be determined.

The effect of coffee consumption on serum cholesterol levels.

OBJECTIVE: Studies investigating the association of coffee consumption and serum cholesterol levels report conflicting results. In an attempt to resolve this controversy, we reviewed the literature to answer the question: Is there a true positive association between coffee consumption and serum cholesterol levels? DATA SOURCES: A Medline database search dating back to 1965 was utilized. Key words used in the search were coffee, caffeine and cholesterol. Cholesterol was expanded to include lipoproteins and LDL-, HDL- and VLDL-cholesterol. All articles that presented cholesterol data in association with coffee consumption were examined for references missed by Medline. Recently published articles were located by a hand search through Current Contents and the latest monthly editions of Index Medicus. STUDY SELECTION: Three reviewers made the decision to include all publications that met the following criteria: a) reported original experimental results; b) reported total serum cholesterol levels; and c) were published in peer-reviewed journals. DATA EXTRACTION: Two to four articles were read and analyzed each week in chronological order. Independent data extraction was performed by three reviewers, who then met as a group once a week to cross-check the analyses. DATA SYNTHESIS: A trend, representing the association between coffee consumption and serum cholesterol, was calculated for each study. The trend was based on the percent difference in cholesterol values between subjects drinking four or more cups of coffee per day in comparison to those drinking zero or less than one cup of coffee each day. In order to compare studies that reported different cup sizes and different levels of intake, weighted mean cholesterol levels were calculated. In studies discussing the data in terms of correlations, trends were established according to the r values provided by the authors. CONCLUSIONS: The majority of studies demonstrated a positive trend in at least one subpopulation of their subjects, indicating that serum cholesterol levels increase with increasing coffee consumption. Stronger trends were seen among subjects drinking boiled coffee than in those drinking filtered, decaffeinated or instant coffee. However, most studies were not randomized clinical trials, and results can be countered by a number of biases prevalent in the studies, indicating the need for additional well-designed investigations to resolve remaining issues.

The effect of spinal manipulation on pain and prostaglandin levels in women with primary dysmenorrhea.

OBJECTIVE: The primary objectives of this study were to compare the effect of spinal manipulation vs. sham manipulation on a) circulating plasma levels of the prostaglandin F2a metabolite, 15-keto-13,14-dihydroprostaglandin (KDPGF2a), b) perceived abdominal and back pain and c) perceived menstrual distress in women with primary dysmenorrhea. DESIGN: This randomized clinical pilot study investigated the outcome measures before and after either a spinal manipulation treatment (SMT) or a sham manipulation. SETTING: All subjects were treated at the National College Chiropractic clinic, a private chiropractic clinic in the suburban Chicago area. PARTICIPANTS: Forty-five women with a history of primary dysmenorrhea were recruited from the local community. The volunteers ranged in age from 20-49 (mean age = 30.3 yr), and were entered into the study between April 1990 and January 1991. Twenty-four were randomly assigned to the spinal manipulation group and 21 were assigned to the sham group. INTERVENTIONS: Subjects treated with spinal manipulation were placed in a side-lying position with the bottom leg straight and the top leg flexed at the knee and hip. They received a high-velocity, short lever, low-amplitude thrust to all clinically relevant vertebral levels within T10 and L5-S1 and the sacroiliac joints. In the sham manipulation, subjects were placed in a side-lying position with both hips and knees flexed. Their manipulation consisted of a similar thrust administered to the midline base of the sacrum. OUTCOME MEASURES: Perceived abdominal and back pain were measured with a visual analog scale, and menstrual distress was measured with the Menstrual Distress Questionnaire. Both were administered 15 min before and 60 min after treatment. Blood samples were collected by venipuncture for the determination of plasma levels of KDPGF2a at the same times. The plasma was then assayed for KDPGF2a by radioimmunoassay. RESULTS: Analysis of covariance and paired Student's t tests were used for the statistical evaluation. Immediately after treatment, the perception of pain and the level of menstrual distress were significantly reduced by SMT. This reduction was associated with a significant reduction in plasma levels of KDGPF2a in the SMT group. A significant and similar reduction in plasma KDPGF2a also occurred in the sham group, indicating that a placebo effect was associated with a single sham intervention. CONCLUSIONS: This randomized pilot study suggests that SMT may be an effective and safe nonpharmacological alternative for relieving the pain and distress of primary dysmenorrhea. However, the large change in KDPGF2a observed in both treatment groups clearly indicates that further studies with more subjects, studied over a longer time frame, are needed to resolve the question of a placebo effect.

Enhanced neutrophil respiratory burst as a biological marker for manipulation forces: duration of the effect and association with substance P and tumor necrosis factor.

A critical need in assessing the clinical utility of manipulative therapy for back pain is the identification of biological changes associated with the forces applied by spinal manipulation. Such changes could then serve as markers for both sham treatment and manipulation. We determined the priming of polymorphonuclear neutrophils for an enhanced respiratory burst and its duration, the priming of mononuclear cells for enhanced endotoxin-stimulated tumor necrosis factor production and plasma levels of substance P following a single thoracic spine manipulation. There was a significant difference in the respiratory burst of polymorphonuclear neutrophils in response to a particulate challenge, depending on the time of blood sample collection. The response of polymorphonuclear neutrophils isolated from blood collected 15 min after manipulation was significantly higher than the response of cells isolated from blood collected 15 min before and 30 and 45 min after manipulation. Mononuclear cells were also primed for enhanced endotoxin-stimulated tumor necrosis factor production by spinal manipulation. Both of these priming effects were accompanied by a slight, but significant elevation in plasma substance P. The mean manipulation force associated with these biological effects was 878 +/- 99 N. These biological effects may provide a means of monitoring the delivery of both sham and manipulative treatment and, therefore, provide a crucial tool for understanding the efficacy of manipulative therapy.

Enhanced phagocytic cell respiratory burst induced by spinal manipulation: potential role of substance P.

The effect of spinal manipulation on the respiratory burst of polymorphonuclear neutrophils (PMN) and monocytes from treated adults was measured by zymosan-stimulated chemiluminescence (CL). Peripheral blood was collected 15 min before and 15 min after treatment (sham manipulation, thoracic spine manipulation, or soft tissue manipulation), the cells were isolated, challenged with a standardized, opsonized luminol-containing suspension of zymosan, and monitored for CL. Plasma from two subsets of subjects was radioimmunoassayed for Substance P (SP). PMN were also preincubated with SP in vitro over the dose range 5 x 10(-12) M to 5 x 10(-8) M and the CL response monitored. The CL responses of both PMN and monocytes from subjects who received spinal manipulation were significantly higher after than before treatment, and significantly higher than the response in sham or soft-tissue treated subjects. Measurement of the force applied by sham and spinal manipulation suggested a force threshold for the enhancement of the CL response. Plasma levels of SP before and after treatment in sham treated subjects did not differ significantly; however, elevated plasma SP was observed in subjects after spinal manipulation. Preincubation of PMN with 1 x 10(-11) M, 5 x 10(-11) M or 1 x 10(-10) M SP in vitro primed PMN for an enhanced respiratory burst when the cells were subsequently challenged.

Evidence for expression of a common myosin heavy chain phenotype in future fast and slow skeletal muscle during initial stages of avian embryogenesis.

We have utilized a key biochemical determinant of muscle fiber type, myosin isoform expression, to investigate the initial developmental program of future fast and slow skeletal muscle fibers. We examined myosin heavy chain (HC) phenotype from the onset of myogenesis in the limb bud muscle masses of the chick embryo through the differentiation of individual fast and slow muscle masses, as well as in newly formed myotubes generated in adult muscle by weight overload. Myosin HC isoform expression was analyzed by immunofluorescence localization with a battery of anti-myosin antibodies and by electrophoretic separation with SDS-PAGE. Results showed that the initial myosin phenotype in all skeletal muscle cells formed during the embryonic period (until at least 8 days in ovo) consisted of expression of a myosin HC which shares antigenic and electrophoretic migratory properties with ventricular myosin and a distinct myosin HC which shares antigenic and electrophoretic migratory properties with fast skeletal isomyosin. Similar results were observed in newly formed myotubes in adult muscle. Future fast and slow muscle fibers could only be discriminated from each other in developing limb bud muscles by the onset of expression of slow skeletal myosin HC at 6 days in ovo. Slow skeletal myosin HC was expressed only in myotubes which became slow fibers. These findings suggest that the initial commitment of skeletal muscle progenitor cells is to a common skeletal muscle lineage and that commitment to a fiber-specific lineage may not occur until after localization of myogenic cells in appropriate premuscle masses. Thus, the process of localization, or events which occur soon thereafter, may be involved in determining fiber type.