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Biomedical subjects

S M Henry

Publications and source records attributed to S M Henry.

At least 37 records · Page 2Linked to original sources
PubMed1995

Structural and immunochemical identification of Leb glycolipids in the plasma of a group O Le(a-b-) secretor.

Total non-acid glycosphingolipids were isolated from the plasma of a healthy red blood cell group O Le(a-b-) salivary ABH secretor individual. Glycolipids were fractionated by HPLC and combined into eight fractions based on chromatographic and immunoreactive properties. These glycolipid fractions were analysed by thin-layer chromatography and tested for Lewis activity with antibodies reactive to the type 1 precursor (Le(c)), H type 1 (Le(d)), Le(a) and Le(b) epitopes. Fractions were structurally characterized by mass spectrometry (EI-MS and LSIMS) and proton NMR spectroscopy. Expected blood group glycolipids, such as H type 1, (Fuc alpha 1-2Gal beta 1-3GlcNac beta 1-3Gal beta 1-4Glc beta 1-1Cer) were immunochemically and structurally identified. Inconsistent with the red cell phenotype and for the first time, small quantities of Le(b) blood group glycolipids (Fuc alpha 1-2Gal beta 1-3(Fuc alpha 1-4)GlcNAc beta 1-4Glc beta 1-1Cer) were immunochemically and structurally identified in the plasma of a Lewis-negative individual. These findings confirm recent immunological evidence suggesting the production of small amounts of Lewis antigens by Lewis negative individuals.

ABO Blood-Group System↗
PubMed1995

The role of somatosensory information in a constrained locomotor task.

The purpose of this project was to study the role of somatosensory information in the performance of a constrained locomotor task by rats and to further examine the influence of structural recovery in the somatosensory thalamus, specifically the ventral posterolateral nucleus (VPL). Groups of rats were trained to traverse an elevated, one inch bar for a reward. The time taken to run across the bar (run time) was used as a measure of the success of the goal-directed behavior. The movement pattern of the hindlimb during the swing phase of the locomotor task was quantified from videotape on Preoperative (PRE) Day 15 and during the 46-day postoperative period. The movement pattern was characterized using six different parameters: the area, the X and Y values of the centroid under the normalized curve of the hindlimb trajectory, the vertical displacement of the hindlimb in the flexion and extension phases of the swing cycle, the maximum instantaneous hindlimb velocity, and the proportion of time spent in the acceleration versus deceleration phases of the swing cycle. In order to disrupt the central pathways for somatosensory information, lesions were made in (i) the right gracile nucleus (GN) (n = 18), (ii) bilateral GN (n = 7), (iii) the right GN and the left VPL (n = 6), and (iv) bilateral VPL (n = 8), and (v) sham-operated animals (n = 5). The run time and the pattern of the hindlimb swing cycle were used as measures of loss and recovery of function. Only the bilateral VPL group showed an impairment in run time and they recovered by Postoperative (POST) Week 4. All groups demonstrated an impairment in initial flexion of the hindlimb during the swing cycle that recovered in the right GN group only. On POST Day 49, the right GN, bilateral GN, and the sham groups received injections of 5% WGA-HRP into both CN to determine the location of these projections in VPL. The CN projections were not redistributed into the gracile area of VPL after GN lesions. Since our previous study (24) had shown the number of synapses in VPL returned to normal after dorsal column nuclei (DCN) lesions by POST Day 50, the recovery of the number of synapses alone was not sufficient to restore the normal gait pattern, while the recovery of the run time preceded the complete recovery of the number of synapses.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Distinguishable groups of musculoskeletal low back pain patients and asymptomatic control subjects based on physical measures of the NIOSH Low Back Atlas.

STUDY DESIGN: The authors performed an empirical prospective study of 115 patients referred to physical therapy for low back pain and 112 control subjects of similar age and gender. OBJECTIVES: The authors defined and compared subgroups based on physical tests and described demographic and psychosocial characteristics by group. SUMMARY OF BACKGROUND DATA: Prospective studies of intervention for persons with low back pain are limited by inability to randomize subjects into distinguishable groups. Previous attempts have not been empirical and have not focused on musculoskeletal LBP. METHODS: Ten physical therapists administered 52 tests and 6 questionnaires to subjects in seven different clinics. Data were subjected to reliability and cluster and comparative analyses. RESULTS: Tests were reliable. Groups were distinguished by measures of symmetry, flexibility, strength, and dynamic mobility. CONCLUSION: Distinguishable groups can be determined; decreased trunk mobility characterized all groups of patients and imbalances in muscle length, strength, and symmetry described specific groups of subjects with and without low back pain.

Cluster Analysis↗
PubMed1994

Expression of Lewis histo-blood group glycolipids in the plasma of individuals of Le(a+b+) and partial secretor phenotypes.

Red cell Lewis antigens are carried by glycosphingolipids passively absorbed from plasma. Plasma was collected from a spectrum of individuals with normal and unusual Lewis/secretor phenotypes in order to investigate the glycolipid basis for the unusual phenotypes. Samples were obtained from: a Le(a+b-) ABH nonsecretor who secreted Lewis substances; a Le(a+b-) partial secretor; Le(a+b+) partial secretors; Le(a+b+) secretors; and a full range of normal Lewis/secretor phenotypes as controls. The Le(a+b+) samples represented Polynesian, Asian and Réunion Island ethnic backgrounds. Nonacid glycolipids were prepared, separated by thin-layer chromatography, and then immunostained with potent monoclonal antibodies of known specificity. Despite different serological profiles of the Le(a+b-) and Le(a+b+) Polynesian samples, their plasma glycolipid expressions were very similar, with both Le(a) and Le(b) co-expressed. The copresence of Le(a) and Le(b) in Le(a+b+) samples is in marked contrast to Caucasians with normal Lewis phenotypes, who have predominantly either Le(a) or Le(b). These results suggest that there is a range of the secretor transferases in different individuals, possibly due to different penetrance or to several weak variants. We also show that Lewis epitopes on longer and/or more complex core chains appear to be predominant in the Polynesian Le(a+b+) samples. The formation of these extended glycolipids is compatible with the concept that in the presence of reduced secretor fucosyltransferase activity, increased elongation of the precursor chain occurs, which supports the postulate that fucosylation of the precursor prevents or at least markedly reduces chain elongation.

Aldehydes↗
PubMed1994

Immunochemical and immunohistological expression of Lewis histo-blood group antigens in small intestine including individuals of the Le(a+b+) and Le(a-b-) nonsecretor phenotypes.

Histological samples and total non-acid glycosphingolipids were prepared from small intestine of human cadavers with the Le(a+b+) and Le(a-b-) nonsecretor phenotypes and contrasted with the more common Lewis phenotypes. Glycolipid fractions were analysed by thin-layer chromatography and tested for Lewis activity with monoclonal antibodies reactive to Lewis epitopes. Paraffin-embedded small intestine sections were also fluorescently immunostained with anti-Lewis antibodies. Unlike the common Lewis positive phenotypes, we were immunochemically able to demonstrate the copresence of large amounts of Lea and Leb glycolipids in the Le(a+b+) sample. In addition we demonstrated increased formation of extended Lewis structures in this phenotype. By immunohistochemistry Lea, Leb and type 1 precursor chain epitopes could be demonstrated in the brush border. These results show that the expression of the Le(a+b+) phenotype at the erythrocyte phenotyping level parallels the small intestinal expression of this phenotype, and the patterns of Lewis antigen expressions are unique to this phenotype. By immunohistochemistry and immunochemistry we also demonstrated the presence of trace amounts of Lewis active glycoconjugates in the small intestine of the Le(a-b-) nonsecretor and Le(a+b-) samples. In the Le(a-b-) nonsecretor Lea and Leb activity was absent and type 1 precursor was present in brush border, while Leb activity was immunohistologically demonstrated in the Golgi apparatus of the deep glands. Trace amounts of both Lea and Leb glycolipids were identified in this sample. In parallel trace Leb activity could also be detected in the glycolipids of the Le(a+b-) sample and could be immunohistologically demonstrated to be fully expressed in occasional cells in the deep glands of the small intestine, a pattern quite dissimilar to that of the Le(a-b-) nonsecretor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Hemodynamic responses to shock in young trauma patients: need for invasive monitoring.

OBJECTIVE: To determine whether early invasive monitoring is necessary in young trauma patients. DESIGN: A prospective study. SETTING: Surgical intensive care unit (ICU) at an inner-city, Level I trauma center. PATIENTS: Thirty-nine patients < 40 yrs of age, who required operative therapy for penetrating trauma and who received > 6 units of intraoperative blood. INTERVENTIONS: Invasive hemodynamic monitoring, with percutaneous insertion of arterial and pulmonary artery catheters. Vital signs, hemodynamic and oxygen transport values, and laboratory tests were obtained at 1, 8, and 24 hrs postoperatively. Oxygen delivery was increased until a normal serum lactate concentration and a state of nonflow-dependent oxygen consumption were achieved. MEASUREMENTS AND MAIN RESULTS: Despite normal heart rate, blood pressure, and urine output, only five (15%) patients achieved an optimized state at 1 hr postoperatively. Of the other 34 patients, two patients achieved an optimized state with volume infusion alone and 32 (82%) patients required inotropes. Five (12%) patients never achieved an optimized state and died within hours of their arrival to the ICU. Two other patients achieved an optimized state but died of sepsis and organ failure. The other 32 (82%) patients achieved an optimized state within 24 hrs and survived. The hemodynamic values of survivors at 1 hr postoperatively showed a significantly lower pulmonary vascular resistance and serum lactate concentration, and a significantly higher oxygen delivery and mixed venous oxygen saturation, when compared with the values of nonsurvivors. At 24 hrs postoperatively, survivors also had a significantly lower pulmonary vascular resistance and serum lactate concentration, and significantly higher oxygen delivery than nonsurvivors. Survivors' oxygen consumption was also higher than the oxygen consumption of nonsurvivors. CONCLUSIONS: Our data demonstrate that young trauma patients have substantial but clinically occult myocardial depression after shock, and most of these patients require inotropes to optimize and clear circulating lactate. Early invasive monitoring is necessary to precisely define the adequacy of the cardiac response and to individually tailor therapy. Patients who do not optimize and clear their lactate within 24 hrs may not survive.

Abdominal Injuries↗
PubMed1994

Detection and characterization of Lewis antigens in plasma of Lewis-negative individuals. Evidence of chain extension as a result of reduced fucosyltransferase competition.

Nonacid plasma glycolipids from Lewis-negative individuals of nonsecretor, partial-secretor and secretor phenotypes were prepared and separated by thin-layer chromatography and immunostained with radiolabelled Lewis antibodies. Lewis-positive plasma and intestinal epithelial cell glycolipids from Caucasians representing the four recognized Lewis and secretor combined phenotypes were used as controls. By presenting these purified total glycolipids in a cell-free environment to Lewis antibodies we were able to demonstrate the presence of small amounts of Lewis antigens in Lewis-negative individuals. It is shown that lactotetraosylceramide and extended precursor glycolipids are present in all Le(a-b-) nonsecretors. Le(a) was detected in 1 of the 3 Le(a-b-) nonsecretor plasmas and in the intestinal sample of the same phenotype. Lactotetraosylceramide was absent but H type 1 and Le(b) were both present in all group O Le(a-b-) secretors, and extended H type 1 reactive structures were also found in the partial secretor. These results clearly demonstrate that although the Lewis-negative phenotype exists at the serological level, this phenotype is not an 'all-or-nothing' phenomenon at the chemical level. We also show that in the presence of reduced fucosyltransferase activity, increased elongation of the precursor chain occurs, which allows us to postulate that fucosylation of the precursor prevents or at least markedly reduces chain elongation.

ABO Blood-Group System↗
PubMed1994

Some endurance measures in persons with chronic low back pain.

Muscle fatigue and lack of endurance are complaints of persons with chronic low back pain, but there are no standard ways to assess endurance in this population. The purposes of this study were to examine three measures of endurance; to determine relationships of these measures to each other; and to describe effects of gender, obesity, smoking, and self-reported fitness on the clinical measures. The measures of endurance selected were not dependent on maximal voluntary muscular contractions. They were the Sorensen test, median frequency decline of selected muscles, and a submaximal bicycle ergometer test. Thirty-five consenting individuals who were referred for treatment answered questions about their daily exercise prior to being tested. Repeatability of the Sorensen test holding time and of the slope measure of decline in the median frequencies was acceptable for subjects who reported a higher activity level. The decline of the median frequency in the biceps femoris muscles correlated with holding time of the Sorensen test. Smoking, gender, or obesity level did not affect test results on any of the endurance measures. Subjects who reportedly were more active achieved significantly higher scores on the Sorensen test. The importance of controlling for self-perception of activity in physical testing is discussed.

Adult↗
PubMed1993

Lactate clearance and survival following injury.

Previous reports cite optimization of O2 delivery (DO2) to 660 mL/min/m2, O2 consumption (VO2) to 170 mL/min/m2, and cardiac index (CI) of 4.5 L/min as predicting survival. We prospectively evaluated 76 consecutive patients with multiple trauma admitted directly to the ICU from the operating room or emergency department. Patients had serum lactate levels and oxygen transport measured on ICU admission and at 8, 16, 24, 36, and 48 hours. Patients were analyzed with respect to survival (S) versus nonsurvival (NS), lactate clearance to normal (< or = 2 mmol/L) by 24 and 48 hours, hemodynamic optimization as defined above, as well as Injury Severity Score (ISS), ICU stay (LOS), and admission blood pressure. All patients achieved non-flow-dependent VO2. There was no difference in CI, DO2, VO2, or ISS when S was compared with NS. All 27 patients whose lactate level normalized in 24 hours survived. If lactate levels cleared to normal between 24 and 48 hours, the survival rate was 75%. Only 3 of the 22 patients who did not clear their lactate level to normal by 48 hours survived. Ten of the 25 nonsurvivors (40%) achieved the above arbitrary optimization criteria. Fifteen of the survivors never achieved any of these criteria. Optimization alone does not predict survival. However, the time needed to normalize serum lactate levels is an important prognostic factor for survival in severely injured patients.

Adolescent↗
PubMed1993

Plasma and red-cell glycolipid patterns of Le(a+b+) and Le(a+b-) Polynesians as further evidence of the weak secretor gene Se(w).

Monoclonal antibodies and thin-layer chromatography were used to study the unusual erythrocyte Lewis phenotypes found in healthy Polynesians. A single monoclonal anti-Leb reagent 073 (clone LM129) was found which could detect Leb antigen on the Polynesian erythrocytes of samples that were unreactive with various polyclonal and monoclonal anti-Leb reagents. Glycolipid fractions prepared from the plasma and erythrocytes of selected Polynesian samples of red-cell Le(a-b-), Le(a+b-) and Le(a+b+) phenotypes were found to have Leb glycolipids. The Leb antigen in some individuals is so weakly expressed that it is undetectable by routine erythrocyte phenotyping. Unusually large glycolipids bearing the Leb epitope were also found in some Polynesian samples, although the contribution of these novel glycolipids to phenotyping is unclear. The inability to detect Leb by routine methods and the presence of novel structures can be partially explained in terms of the presence of a weak secretor gene Se(w).

Chromatography, Thin Layer↗
PubMed1993

A possible relationship between colorectal carcinoma and ABO/Lewis blood groups.

The incidence of colorectal carcinoma was compared with the incidence of ABO and Lewis blood groups. The raw data showed the known overrepresentation of the Le(a-b) phenotype, but also suggested an association of colorectal carcinoma with the Le(a-b+) phenotype in group O individuals. When the data were adjusted by taking into account the known loss of Lewis antigens by Lewis-positive patients, this association could be shown to be statistically significant. These results may indicate involvement of the secretory H antigen in colorectal carcinoma.

Journal Article↗
PubMed1993

Endurance training of trunk extensor muscles.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the effects of an endurance exercise protocol on the isometric holding time of the trunk extensor muscles (mechanical fatigue measure) and on the recorded median frequency (MF) measurements from the surface electromyogram (physiological fatigue measure). SUBJECTS: Twenty-eight healthy female volunteers were selected to participate in the study. METHODS: The subjects were stratified by activity level and then assigned to an exercise or a control group and tested at weeks 0, 3, and 6. Reliability (r) of the measurements, established by testing each subject twice at week 0, was .87. Exercise group subjects trained at home twice daily for 6 weeks, progressing by established protocol. RESULTS: The exercise group subjects increased their isometric holding time by 22% after 6 weeks. The control group showed no significant changes. CONCLUSION AND DISCUSSION: The home program was believed to be effective for increasing isometric endurance of the trunk extensors, measured by holding time. The MF measurements prior to and just after a fatiguing contraction remained stable over time. The change in the slope of the MF with fatigue did not reach statistical significance. This physiologic measure of fatigue did not show commensurate changes with training in this group of subjects. Possible reasons for the results are discussed.

Adult↗
PubMed1991

Influence of endogenous and exogenous electron donors and trichloroethylene oxidation toxicity on trichloroethylene oxidation by methanotrophic cultures from a groundwater aquifer.

Trichloroethylene (TCE)-transforming aquifer methanotrophs were evaluated for the influence of TCE oxidation toxicity and the effect of reductant availability on TCE transformation rates during methane starvation. TCE oxidation at relatively low (6 mg liter-1) TCE concentrations significantly reduced subsequent methane utilization in mixed and pure cultures tested and reduced the number of viable cells in the pure culture Methylomonas sp. strain MM2 by an order of magnitude. Perchloroethylene, tested at the same concentration, had no effect on the cultures. Neither the TCE itself nor the aqueous intermediates were responsible for the toxic effect, and it is suggested that TCE oxidation toxicity may have resulted from reactive intermediates that attacked cellular macromolecules. During starvation, all methanotrophs tested exhibited a decline in TCE transformation rates, and this decline followed exponential decay. Formate, provided as an exogenous electron donor, increased TCE transformation rates in Methylomonas sp. strain MM2, but not in mixed culture MM1 or unidentified isolate, CSC-1. Mixed culture MM2 did not transform TCE after 15 h of starvation, but mixed cultures MM1 and MM3 did. The methanotrophs in mixed cultures MM1 and MM3, and the unidentified isolate CSC-1 that was isolated from mixed culture MM1 contained lipid inclusions, whereas the methanotrophs of mixed culture MM2 and Methylomonas sp. strain MM2 did not. It is proposed that lipid storage granules serve as an endogenous source of electrons for TCE oxidation during methane starvation.

Biotransformation↗
PubMed1991

Inhibition of trichloroethylene oxidation by the transformation intermediate carbon monoxide.

Inhibition of trichloroethylene (TCE) oxidation by the transformation intermediate carbon monoxide (CO) was evaluated with the aquifer methanotroph Methylomonas sp. strain MM2. CO was a TCE transformation intermediate. During TCE oxidation, approximately 9 mol% of the TCE was transformed to CO. CO was oxidized by Methylomonas sp. strain MM2, and when formate was provided as an electron donor, the CO oxidation rate doubled. The rate of CO oxidation without formate was 4.6 liter mg (dry weight)-1 day-1, and the rate with formate was 10.2 liter mg (dry weight)-1 day-1. CO inhibited TCE oxidation, both by exerting a demand for reductant and through competitive inhibition. The Ki for CO inhibition of TCE oxidation, 4.2 microM, was much less than the Ki for methane inhibition of TCE oxidation, 116 microM. CO also inhibited methane oxidation, and the degree of inhibition increased with increasing CO concentration. When CO was present, formate amendment was necessary for methane oxidation to occur and both substrates were simultaneously oxidized. CO at a concentration greater than that used in the inhibition studies was not toxic to Methylomonas sp. strain MM2.

Biotransformation↗
PubMed1990

Investigation of Lewis phenotypes in Polynesians: evidence of a weak secretor phenotype.

The salivary ABH and Lewis antigens of Polynesians were measured using a standardised red cell agglutination microplate assay and compared with the red cell defined Lewis phenotypes. Salivary ABH substances were detected in almost all saliva samples tested, with low levels (partial secretion) of ABH substances in the saliva from Le(a+b-) and Le(a+b+) individuals. Salivary Leb substance was detected in all Le(a-b+) and Le(a+b+) samples and in almost all Le(a+b-) samples. It is evident from the results obtained that Polynesian red cell phenotypes cannot be used to predict the presence or absence of salivary substances. If the presence of a coding secretor gene is presumed responsible for salivary ABH antigens and salivary Leb antigen expression, then the incidence of a coding secretor gene in Polynesians is 98%. These results indicate that the recessive non-secretor gene is absent or rare in a Polynesian derived gene pool. Two variants of secretor individuals are found among Polynesians, secretors with expression of normal amounts of the product of the secretor gene, similar to Caucasians, and partial secretors with weak expression of the secretor gene products.

ABO Blood-Group System↗
PubMed1988

The Le(a+b+) phenotype in Polynesians.

The presence of the rare Lewis phenotype Le(a+b+) is reported in various Polynesian groups, including Maoris, Samoans, Cook Islanders, Nuieans and Tokelau Islanders. The phenotype was found in Polynesians of all blood groups and the frequency was significantly increased in group 0 persons. The phenotype was not significantly associated with H reactivity in group A donors and showed no correlation with age or sex.

ABO Blood-Group System↗
PubMed1988

Evaluation of monoclonal anti-A reagents by salivary inhibition studies.

Ten commercially available monoclonal and polyclonal anti-A reagents were evaluated for use in the test for ABH secretor status after finding unexpected inhibition with a monoclonal anti-A (reagent Z). Two of the available monoclonal reagents were from different batches from the same clone as reagent Z. Those two reagents, as well as reagent Z, appeared to be partially neutralized by salivary substances from group A nonsecretor individuals. This finding suggests that when a saliva inhibition test is done, a nonsecretor control saliva of the same ABO group as the saliva to he tested should be used.

Journal Article↗