Ketone production in ultra marathon runners.

AIM: The aim of this study was to determine the magnitude of ketone production in ultra marathon runners and what affect if any this has on performance. METHODS: Participants in the Cliff Young Australian Six Day Race (n=31) provided a prerace urine sample and, then, random urine samples throughout the duration of the event, ranging from 4-20 samples each. Based on urinalysis results, participants were divided into two groups: those who formed ketones (ketone group), and those who did not form ketones or formed ketones only once during a race at the lowest recordable value (non-ketone group). RESULTS: The average ketone level of the 22 athletes in the ketone group (value+/-standard deviation: 5.67+/-5.59 mg/dL) was statistically different from 9 athletes who were in the non-ketone group (0.18+/-0.14 mg/dL) (P<0.05). The average distances run for the two groups were 498.09+/-153.99 and 535.6+/-181.08 km, respectively (P=0.56). When average ketone value was compared, excluding runners who did not complete the race, the ketone group (5.88+/-1.37) remained statistically different from the non-ketone group (0.2+/-0.45) (P<0.05). The average distances for those athletes who completed the race were 583.9+/-116.09 and 557.8+/-85.82 km, respectively (P=0.52). CONCLUSION: We conclude that although two runner sub-populations were revealed, runners who produce ketones and runners who do not make ketones, the level of ketones produced did not affect overall distance run, which is the performance criterion of the race. The nature of this extreme event has illuminated a physiologic difference among ultra marathon runners, and although this difference does not appear to affect race performance, the long-term health consequences are unknown and additional rigorous research is warranted.

The effect of light exercise upon blood flow velocity determined by laser-Doppler flowmetry.

PRIMARY OBJECTIVE: The dominant, 0.1 Hz frequency, Traube-Hering component of blood flow velocity, which is related to baroreflex activity, may be modulated through the established techniques of manipulative medicine. Light exercise programmes, appropriate for use by the elderly and collectively termed gymnastique douce, also are believed to impact the baroreflex in a positive manner. Our objective was to test the relationship between the Traube-Hering oscillation and light exercise. METHODS: Using laser-Doppler flowmetry to quantify the Traube-Hering and other components of the blood flow velocity oscillation, we compared flowmetry records of 10 subjects before and immediately following a light-exercise programme. RESULTS: The data show that the light exercise programme amplifies the 0.1 Hz component of the blood flowmetry record. CONCLUSIONS: The 0.1 Hz component of blood-flow velocity is physiologically linked to baroreflex activity. It is this component that is augmented by a light exercise programme.

Correlation of lipid layer thickness measurements with fluorescein tear film break-up time and Schirmer's test.

PURPOSE: This study correlates measurement of lipid layer thickness (LLT) with two frequently used dry eye tests, fluorescein break-up time (FBUT) and Schirmer's test with anaesthesia (STA). METHODS: Subjects (n = 44 eyes) with symptoms of dry eye and positive results for dry eye with either FBUT or STA or both were selected. Quantification of LLT was performed by the observation of colour interference patterns in zones of specular reflection using a custom-designed instrument. RESULTS: All correlations among pairs of tests were strong and exhibited a significance of P < 0.000: STA with FBUT, Pearson's correlation 0.653; STA with LLT, 0.764; FBUT with LLT, 0.751. When LLT was high, ie > or = 120 nm, which occurred in 14 eyes, STA was also elevated in those eyes and FBUT was high in 13 of the 14 eyes. When LLT was low, ie < or = 60, which occurred in 22 eyes, STA was below normal in 14 of the 22 eyes, and FBUT was below normal in 15 of the 22 eyes. These clinical observations paralleled the statistical findings computed from the entire data set. CONCLUSIONS: The correlations demonstrated in this study support the premise (1) that measurement of LLT is a reliable test for the diagnosis of dry eye, and (2) that aqueous deficiency and lipid deficiency, as they apply to dry eye disorders, are not mutually exclusive.

Cranial rhythmic impulse related to the Traube-Hering-Mayer oscillation: comparing laser-Doppler flowmetry and palpation.

The primary respiratory mechanism (PRM) as manifested by the cranial rhythmic impulse (CRI), a fundamental concept to cranial osteopathy, and the Traube-Hering-Mayer (THM) oscillation bear a striking resemblance to one another. Because of this, the authors developed a protocol to simultaneously measure both phenomena. Statistical comparisons demonstrated that the CRI is palpably concomitant with the low-frequency fluctuations of the THM oscillation as measured with the Transonic Systems BLF 21 Perfusion Monitor laser-Doppler flowmeter. This opens new potential explanations for the basic theoretical concepts of the physiologic mechanism of the PRM/CRI and cranial therapy. Comparison of the PRM/CRI with current understanding of the physiology of the THM oscillation is therefore warranted. Additionally, the recognition that these phenomena can be simultaneously monitored and recorded creates a new opportunity for further research into what is distinctive about the science and practice of osteopathic medicine.

Standardized medical record: a new outpatient osteopathic SOAP note form: validation of a standardized office form against physician's progress notes.

The accuracy and efficiency of recording information on a one-page standardized Outpatient Osteopathic SOAP Note Form (SNF) was compared with that obtained using the physician's progress notes (PPN). Use of the SNF in lieu of the PPN would assure the physician that proper clinical data were recorded to ensure proof of need and care in any instances of refused reimbursement. Moreover, standardized SNFs could be used to document and analyze present treatment protocols, enabling medical advances. Ten osteopathic physicians, who were skilled in osteopathic manipulative treatment (OMT), enrolled 300 patients. Initial and follow-up examinations totaled 959 visits (statistical cases); 76 statistical variables were compared. Essentially all information recorded in the PPN was recorded on the SNF. A significant difference (P < .05) was found between the PPN data set and the SNF data set in all but 17 of the 76 variables. Greater content of information almost always was found with the SNF data set. In addition, the SNF contained information not found in the PPN, most notably the severity and response to treatment of detected somatic dysfunctions. Participating physicians stated that the SNF takes about the same amount of time to fill in as the PPN. This makes the SNF a practical instrument for accurately and efficiently obtaining patient data in all physicians' offices. The validation study conducted demonstrated that the Outpatient Osteopathic SOAP Note Form easily and accurately reflected information recorded in the PPN and that data recorded may be used by physicians in their individual practices or for the conduct of osteopathic research.

Esophageal cancer phospholipids correlated with histopathologic findings: a 31P NMR study.

We analyzed 36 esophageal tumor specimens for phospholipid content using phosphorus nuclear magnetic resonance spectroscopy (31P NMR) and correlated the individual phospholipid profiles with specific clinical and histopathologic features. Among the 18 phospholipids identified in the esophageal tumor specimens, the mean mole percentage concentration of dimethylphosphatidylethanolamine, lysoalkylacylphosphatidylcholine, lysophosphatidic acid, lysophosphatidylcholine (deacylated at the glycerol-1 carbon), and lysoethanolamine plasmalogen correlated with pathologic T stage, nuclear grade, or the presence of lymphatic invasion. 31P NMR produces well-dispersed phospholipid spectra and a precise determination of phospholipid relative mole percentages. These data provide a statistical correlation between histopathologic features and molecules known to play an important role in cellular activities and processes unique to malignant tissues.

Effects of eyelid scrubbing on the lid margin.

PURPOSE: To compare the effects of eyelid scrubbing with an eyelid cleansing solution (ECS) to eyelid scrubbing with ECS and the addition of antibacterial or anti-inflammatory pharmaceuticals on the clinical appearance, microbial status, tissue histology, and the inflammatory cell profile of the normal eyelid margin. METHODS: Eyelid scrubbing was performed twice daily using ECS; ECS with the antibacterial sulfacetamide (ECS+); and ECS with sulfacetamide and prednisolone acetate (ECS++) over a 21 day period on three groups of 16 rabbits with clinically normal eyelids. RESULTS: Significant hyperemia of the margin occurred in all three groups over the 3 week period; however, the degree of hyperemia was less with ECS+ (P<0.05) and ECS++ (P<0.05). Chemosis, tearing, mucus discharge, and the microbial status were not significantly different than controls. There were no marked histologic differences in the tissues, except for increased red blood cell packing in the small vessels near the lid margins in scrubbed eyelids, consistent with hyperemia. The inflammatory cell profile showed minimal changes that were not statistically significant in any of the three groups, except that >50% of mast cells showed evidence of degranulation. CONCLUSIONS: Use of ECS with an antibiotic, or an antibiotic and steroid solution, resulted in less inflammation than scrubbing with ECS alone.

Epidermal and dermal phospholipids of the human eyelid: a 31P nuclear magnetic resonance spectroscopy study.

The phospholipids of the skin are difficult to quantify because they represent only a small fraction of the skin tissue. In this study, 31P nuclear magnetic resonance, which permits precise profiling of these phospholipids, was used to compare the phospholipids of upper eyelid epidermal and dermal lipid extracts (n = 13 profiles). Phospholipid profiles included alkylacylphosphatidylcholine (AAPC), dihydrosphingomyelin (DHSM), diphosphatidylglycerol (cardiolipin), ethanolamine plasmalogen (EPLAS), lysophosphatidylcholine, phosphatidic acid, phosphatidylcholine (PC), phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, sphingomyelin, and uncharacterized phospholipids (U1 and U2, particularly enriched in the epidermis). The computed phospholipid metabolic index (n = 86 indexes) findings can be summarized as follows: a lower content of the en-ol and ether phospholipids in the epidermis relative to the dermis, internal compensation among the component phospholipids so as to maintain the choline functional group ratio, and a greater concentration of hydroxyl-containing functional groups in the epidermis. A membrane index (fmem) value of -0.37 for the epidermis deviated considerably from the value of -0.06 characteristic of living membranes and the dermis. The production of the reduced phosphatides, EPLAS and AAPC, indicates the use of alternative pathways between the two tissues. Relative to the dermis, increased PC in the epidermis coupled with decreased DHSM, EPLAS, and AAPC are factors enabling the epidermis of eyelid tissue to be an effective water barrier.

Quantification of lumbar intradiscal deformation during flexion and extension, by mathematical analysis of magnetic resonance imaging pixel intensity profiles.

STUDY DESIGN: A magnetic resonance imaging study of the internal kinematic response of normal lumbar intervertebral discs to non-weight-bearing flexion and extension. OBJECTIVES: To quantify the pattern of magnetic resonance imaging pixel intensity variation across discs, and noninvasively monitor displacement of the nucleus pulposus during sagittal-plane movements. SUMMARY OF BACKGROUND DATA: Invasive techniques used to study intradiscal movements of the nucleus pulposus have suggested that it moves posteriorly during flexion and anteriorly during extension. A noninvasive study based on magnetic resonance images gave similar results for normal young women. Quantification has been problematic, and the invasive procedures may have altered disc dynamics. METHODS: Ten male subjects (age, 21-38 years) with healthy backs were positioned in a magnetic resonance imaging portal with their lumbar spine stabilized in flexion and extension by supporting pads. For each disc, a T2-weighted image was obtained, as was a computer-generated profile of pixel intensities along a horizontal mid-discal transect. Mathematical curve-fitting regression analysis was used to characterize the shape of the intensity profile and to compute the point of maximum pixel intensity. RESULTS: A single equation fitted the profile for all normal discs. The intensity peak shifted posteriorly during flexion, anteriorly during extension. CONCLUSIONS: Automated mathematical modeling of magnetic resonance imaging pixel data can be used to describe the fundamental shape of the pixel intensity profile across a normal lumbar disc, to determine the precise location of the site of maximum pixel intensity, and to measure the movement of this peak with flexion and extension. This technique may be of value in recognizing incipient degenerative changes in lumbar discs.

Ex vivo phosphorus magnetic resonance spectroscopy on eye bank corneas and corneal metabolic health.

BACKGROUND: Since a potential exists for untoward effects on the cornea from the high magnetic fields and radio-frequency energies, and the further manipulation required for phosphorus-31 magnetic resonance spectroscopy (31P-MRS), we determined the effects of this technology on tissues using paired human corneas (n = 4) meeting criteria acceptable for transplantation. METHODS: Slit-lamp biomicroscopy, pachometry, specular microscopy, and redux fluorophotometry were performed on all corneas. One cornea of each pair was examined (< 30 min) by 31P-MRS. Following 31P-MRS, slit-lamp biomicroscopy, pachometry, and redox fluorophotometry were again performed. RESULTS: Data tabulated included the 31P energy modulus (1.37 +/- 0.28), the ATP/Pi (2.92 +/- 0.59) and SP/Pi (0.76 +/- 0.04) ratios, and the intracorneal pH (7.24 +/- 0.09). CONCLUSION: Since there were no significant differences in slit-lamp biomicroscopy, endothelial density and morphometry, cell counts, and pachometric and redox fluorophotometric measurements between corneas of each pair before and after 31P-MRS analysis, it was concluded that there was no detectable metabolic damage secondary to such analysis. This study suggests that MRS analysis of human eye-bank tissues does not damage the cornea metabolically and may provide a practical evaluation of the health of the cornea at the biochemical level.

Comparing psychotic and affective disorders by musculoskeletal structural examination.

Groups of hospitalized patients with psychotic and affective disorders (N = 60) underwent musculoskeletal structural examination. Psychotic and affective disorders each tend to affect a different portion of the musculoskeletal system, with psychotic patients exhibiting increased musculoskeletal dysfunction in the lower extremities and affective-disorders patients exhibiting increased cervical and thoracic dysfunction. At the clinical level, the structural examination may be used to correlate psychiatric disorders with dysfunctional regions of the musculoskeletal system.

Meibomian gland phospholipids.

The content of the meibomian gland lipid exprimate is known, but little is known about the phospholipids that comprise the glandular cells. The purpose of the present study is to identify and quantitate the phospholipid complement of the meibomian gland cells that produce the lipid secretion of meibomian oil and which is vital to tear film stability. Eyelids (n = 50) were excised from rabbits, and after surgical removal of surrounding tissues, the tarsal plates with and without expressing meibomian oil were extracted and phospholipids of the plates quantified by 31P nuclear magnetic resonance (NMR). Seventeen phospholipids were quantified from tarsal plates expressed of oil and tarsal plates containing meibomian oil: alkylacylphosphatidylcholine (AAPC), dihydrosphingomyelin (DHSM), dimethylphosphatidylethanolamine, diphosphatidylglycerol (cardiolipin), ethanolamine plasmalogen (EPLAS), lysoethanolamine plasmalogen, lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylserine, phosphatidic acid, phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, sphingomyelin (SM), sphingosylphosphorylcholine. The six zwitterionic and neutral phospholipids, DHSM, EPLAS, PE, SM, AAPC, and PC together comprise 79.5% of the total meibomian gland phospholipid profile (in meibomian oil this value is 84.2%). The zwitterionic and neutral phospholipids dominate meibomian gland phospholipid profiles. Since the meibomian gland cells undergo holocrine secretion and form the meibomian glad secretion, such a composition is consistent with the hypothesis that a chemically stable lamellar surfactant layer phospholipids bind non-polar meibomian oil to the aqueous layer of the tear film.

Effect of periocular humidity on the tear film lipid layer.

The purpose of this study was to determine the relationship between the tear film and humidity by examining whether alterations in periocular humidity influence the thickness of the tear film lipid layer. Thirteen dry eye subjects presenting with a baseline lipid layer thickness of < or = 60 nm were fitted with modified swim goggles in which the right eye (OD) was exposed to conditions of high humidity and the left eye (OS) remained exposed to ambient room conditions. The lipid layer was monitored over a 60-min time course with goggles on and for an additional 60 min following goggle removal. The OD lipid layer increased significantly in thickness within 5 min of exposure to conditions of high humidity (p < 0.0001), reaching a maximum increase of 66.4 nm after 15 min of goggle wear (p < 0.0001). This maximum increase to a lipid layer thickness of 120.5 nm was maintained at the 30- and 60-min goggle time points. No significant change was detected OS. Following goggle removal, OD values declined but remained significantly elevated over the OS lipid layer thickness throughout the 60-min postgoggle period. Moderate to total relief of dry eye symptoms was reported during goggle wear and generally persisted at a reduced level for 1-3 h following goggle removal. Increased periocular humidity results in an increase in tear film lipid layer thickness, possibly by providing an environment that is more conducive to the spreading of meibomian lipid and its incorporation into the tear film.

Tear film lipid layer formation: implications for contact lens wear.

An overview of the relation between lipid layer formation and contact lens wear is provided, with particular emphasis on factors that influence the delivery and spreading of lipid on the tear film. The disruption of the lipid layer by a contact lens is discussed, as well as factors that may enhance the stability of the prelens tear film lipid layer.

Phospholipids in meibomian gland secretion.

The bulk of the lipid layer overlying the aqueous portion of the precorneal tear film is composed of polar and nonpolar components. The nonpolar lipids have been the subject of numerous studies; however, the polar lipids have remained relatively uncharacterized. The polar lipids are thought to contain surfactant phospholipids that are critical to the spreading of a lipid film over the aqueous layer, by providing an interface between this layer and the nonpolar lipids. The purpose of the present study is to identify and quantitate the phospholipid complement of meibomian gland secretion which provides the tear film with phospholipids. Meibomian gland secretion was collected from rabbits and phospholipids identified and quantitated by 31P nuclear magnetic resonance spectroscopy. Ten phospholipids were detected from meibomian gland secretion: diphosphatidylglycerol, dihydrosphingomyelin, ethanolamine plasmalogen, phosphatidylethanolamine (PE), phosphatidylserine, sphingomyelin, lysophosphatidylcholine, phosphatidylinositol, alkylacylphosphatidylcholine, and phosphatidylcholine (PC). The two major phospholipids were PC and PE, together comprising nearly 60% of the total phospholipid profile. The nature and relative concentrations of the meibomian gland secretion phospholipids are congruous with a surfactant role at the aqueous-lipid interface and, considering the physical chemistry of the tear film, suggest that the phospholipids should be organized in a very flat or planar configuration.

Phospholipid profiling of sediments using phosphorus-31 nuclear magnetic resonance.

A phosphorus-31 nuclear magnetic resonance method has been developed for the determination of aquatic sediment phospholipid profiles that may be generally applied to all soils and deposits containing viable cellular material. A method of scrubbing chloroform/methanol extracts with potassium acid phosphate overcomes adverse signal broadening from the mineral component, permitting eleven sediment phospholipids to be determined at the quantitative level.