Biomedical subjects

B A Smith

Publications and source records attributed to B A Smith.

At least 37 records · Page 2Linked to original sources

PubMed1999

Thomas Henry Storey, D.O., D.C. 1843 to 1923.

Who was Thomas Henry Storey? Dedicated healer or charlatan? A danger to his patients or hero to the profession? He graduated from the Palmer School and Infirmary of Chiropractic in 1901. One of the largest chiropractic colleges, the Los Angeles College of Chiropractic, would be founded by one of his patients in 1910 and incorporated in 1911. He led the founder of chiropractic on his first expedition to Los Angeles. Thomas' seventy-nine year life span took him from Canada through the north central United States to the West Coast from Washington to California and south into Mexico. He was, at various times, a taxidermist, a farmer and, in later years, a rancher. He studied and practiced many types of healing and even operated a chiropractice school for a time. He invented the most ubiquitous of all chiropractic equipment, the bifid table. Whether he desired it or not, Thomas was often thrust into the spotlight, usually under less than admirable circumstances. Even in death, the remnants of his life remained a complicated morass that took sixteen years to resolve in the courts. It is hoped this article will shine some light on a colorful chiropractic pioneer who has been shrouded in a veil of mystery.

Chiropractic↗

PubMed1998

Uroplakin gene expression by normal and neoplastic human urothelium.

cDNA sequences for human uroplakins UPIa, UPIb, UPII, and UPIII were cloned and used to investigate uroplakin transcription by normal and neoplastic urothelial cells. Normal urothelium expressed mRNA for all four uroplakins, although UPIII could be detected only by ribonuclease protection assay. By in situ hybridization, UPIa and UPII were confined to superficial cells and UPIb was also expressed by intermediate cells. Cultured normal human urothelial cells showed a proliferative basal/intermediate cell phenotype and constitutive expression of UPIb only. Uroplakin expression by transitional cell carcinoma cell lines was related to their differentiated phenotype in vitro. RT4 cells expressed all uroplakins, VM-CUB-3 expressed three uroplakins, RT112 and HT1376 cells expressed only UPIb in high abundance, and COLO232, KK47, and EJ cells had no detectable expression. These results correlated with patterns of uroplakin expression in tumors. UPIa and UPII were detected superficially only in well differentiated transitional cell carcinoma papillae. UPIb was positive in seven of nine and overexpressed in five of nine noninvasive transitional cell carcinomas and was also present in four of eight invasive transitional cell carcinomas. Lymph node metastases retained the same pattern of UPIb expression as the primary tumor. Unlike the three differentiation-regulated uroplakins, UPIb may have an alternative role in urothelial cell/tissue processes.

Amino Acid Sequence↗

PubMed1998

Stepping as an exercise modality for improving fitness and function.

This article describes three stepping modes, summarizes research on stepping in healthy adults and patients with peripheral vascular disease, and discusses clinical implications and directions for future research. Stepping exercise has been shown to increase cardiorespiratory fitness in healthy adults and increase physical function in patients with peripheral vascular disease. Although further research is warranted, stepping exercise has potential value as a nursing intervention to correct alterations in physical mobility in selected populations. Stepping is proposed as an alternative exercise strategy; one which adds variety to exercise routines and may enhance long-term exercise adherence.

Activities of Daily Living↗

PubMed1998

Evaluation of a commercial accelerometer (Tritrac-R3 D) to measure energy expenditure during ambulation.

This study evaluated the ability of a commercially available accelerometer (Tritrac-R3 D) to measure energy expenditure in 16 subjects at rest (pre- and post-exercise) and during three different intensities of steady-state exercise (40-70% of peak oxygen consumption [VO2peak]) while ambulating on a treadmill (no grade). Oxygen consumption and the respiratory exchange ratio from indirect calorimetry and the vector magnitude of triaxial accelerations were used to estimate energy expenditure using the manufacturers' equations. There was a significant relationship between indirect calorimetry-derived energy expenditure and the energy expenditure derived from the accelerometer (r=0.96). Using analysis of variance, there was no difference in the energy expenditure derived by the two methods at rest before exercise and during the three different intensities of ambulatory exercise. There was a significant difference between energy expenditure derived via indirect calorimetry and with the accelerometer during rest after exercise, probably due to the failure of the accelerometer to accurately estimate the energy expenditure associated with the progressive decline in post-exercise oxygen consumption. Thus, this commercially available accelerometer appears to provide statistically acceptable estimates of energy expenditure at rest and during zero-grade treadmill ambulation up to about 70% VO2peak. This may indicate its acceptable utility for large-scale population studies of physical activity involving this mode of movement. The failure of the accelerometer to accurately estimate energy expenditure during recovery from exercise may contribute to an underestimation of energy expenditure in some physically active individuals.

Adult↗

PubMed1998

A qualitative assessment of inner city elementary school children's perceptions of their neighborhood.

Three hundred seventy-nine youths from an inner city elementary school were surveyed to determine their perceptions of their neighborhood. Using a qualitative, word association format, older students responded to 20 descriptive words (e.g., dirty, safe, quiet, dangerous) while younger youths drew pictures in response to three words (safe, sad, happy). Using content analysis techniques, findings indicated that the youths found neighborhood areas and residents that were perceived as safe, quiet, beautiful, friendly, fun/happy, and helpful. However, safety issues and a dirty, noisy neighborhood also emerged as major themes. Collaborative initiatives focusing on cleaning up the neighborhood and reducing violence are suggested, as are areas of intervention and further research.

Age Factors↗

PubMed1998

C.D. Greenall, D.C. and the 1907 California Medical Practice Act.

The development of the legal status of the chiropractic profession often resulted from continual persecution by the medical authorities who held almost exclusive power to license health care providers. While the medical boards may seem to offer an "olive branch" in the legislative wars over licensure in the form of drugless practitioner licenses, naturopathic endorsements, or licenses under the "all other" category, their goal was to contain and eliminate all rival professions. A previous article dealt with the prosecution of C.D. Greenall, D.C., at the hands of the medical board. Since writing that article, I have had the opportunity to read The Chiropractor and to develop more fully an understanding of Dr. Greenall and his actions. Not all prosecutions of chiropractic doctors were instigated by the medical profession; some were insisted upon by other chiropractic doctors. Dr. Greenall and his legal counsel were just such a team. With a goal of having California's 1907 Medical Practice Act declared unconstituional, Dr. Greenall presented himself for prosecution. This article more fully details Dr. Greenall and his attempts to gain some form of recognition for the chiropractic profession.

Chiropractic↗

PubMed1998

The problem drinker's lived experience of suffering: an exploration using hermeneutic phenomenology.

Research in the area of problem drinking has traditionally relied on quantitative methodologies which view the problem from the researcher's perspective. The purpose of this hermeneutic-phenomenological study was to describe and understand the problem drinker's lived experience of suffering using a philosophy and research approach which preserves the uniqueness of the experience from the sufferer's point of view. The method involved conducting in-depth interviews with a sample of six problem drinkers. Interviews were analysed using an interpretive process, which aimed at generating a deeper understanding of the topic by facilitating a fusion of the world views of both participant and researcher. A reflexive journal recorded the involvement of the self of the researcher throughout the research process. Suffering was viewed as a spiralling vicious circle of physical, psychological, social and spiritual distress. Symptoms of physical dependence, shame and guilt emerged strongly as being both sequelae of heavy drinking and cues to further drinking bouts. Evoking memories of previous suffering through telling one's story was found to be an empowering and motivating force. The results have relevance to specialist and generic workers, who are urged to pay greater attention to the social, psychological and spiritual care of problem drinkers.

Adult↗

PubMed1997

Analysis of mutations in the K-ras and p53 genes of lung tumors and in the hprt gene of 6-thioguanine-resistant T-lymphocytes from rats treated with 1,6-dinitropyrene.

Direct pulmonary instillation of 1,6-dinitropyrene (DNP) into male Fischer 344 rats results in a dose-dependent induction of lung tumors and 6-thioguanine-resistant (TGr) T-lymphocytes. The treatment also results in DNP binding to dG in the lung and in T-lymphocytes. In the present study, we have examined the types of mutations associated with these responses to DNP. Sequencing of DNA amplification products from 20 DNP-induced lung tumors identified 5 mutations in K-ras codon 12, 4 GGT-->TGT transversions and one GGT-->GAT transition. No mutations were found in K-ras codons 13 or 61. Single-strand conformation polymorphism analysis of p53 exons 5-8 revealed mobility shifts indicative of mutation in 9 of the 20 tumor samples. Eight of the mutations were substitutions at G:C base pairs, and one was a deletion of a single G:C base pair. DNA from 161 TGr lymphocyte colonies cultured from DNP-treated rats was examined for point mutations by amplification of hprt exons 2, 3, and 8, and screening the products for mutant: wild-type heteroduplex formation by denaturing gradient-gel electrophoresis. Only three mutations were found, a G-->T transversion in exon 3, a G-->A transition in exon 8, and a complex mutation consisting of a tandem G-->T transversion and a one base deletion in exon 3. The mutations identified in the DNP-induced lung tumors and TGr T-lymphocytes are consistent with the formation of dG-DNA adducts by DNP. The extremely low recovery of point mutations from TGr lymphocytes suggests that DNP induces a substantial number of mutations by other mechanisms.

Animals↗

PubMed1997

Motoric responses to sucrose in postmature and term infants.

Postmature infants calm less when presented with sucrose solutions than term infants. To further assess the influence of postmaturity on sucrose responsivity, several motoric responses were examined in healthy term neonates and chronically stressed postmature (> or = 288 days gestational age (GA) e.g., > 41 weeks) neonates with Clifford's Syndrome tested between 5-91 h of age. Following baseline observations, each subject was presented with 0.1 ml of a 14% sucrose solution for 10 s each min for 5 min, and observations were continued for 5 min following stimulation. During sucrose stimulation and poststimulation phases, postmature infants showed more tremors during quiet state than term infants. Across conditions, postmature infants exhibited increased finger sucking, rhythmic sucking, but less mouth opening and arm movements than healthy, term infants. Sequence analysis revealed that short-latency mouthing, repetitive movements of the upper and lower lips, followed sucrose infusion reliably in postmature infants, but not term infants. These results suggest that postmaturity is associated with: 1. Increased oral behaviors associated with arousal and self soothing; and 2. Increased sucrose reactivity, as indicated by contingent mouthing and increased tremors.

Arousal↗

PubMed1997

Follicular dendritic cells (FDC) in retroviral infection: host/pathogen perspectives.

Follicular dendritic cells (FDC) are found in the follicles of virtually all secondary lymphoid tissues. In health, these cells trap and retain antigens (Ag) in the form of immune complexes and preserve them for months in their native conformation. FDC thus serve as a long-term repository of extracellular Ag important for induction and maintenance of memory responses. In retroviral infection, FDC trap and retain large numbers of retroviral particles with profound effects on FDC. FDC-trapped retrovirus induces follicular hyperplasia, and conventional Ag trapped prior to infection are lost and new Ag cannot be trapped. Concomitantly, antibody-forming cells (AFC) specific for Ag lost from FDC decrease followed by loss of specific serum antibody (Ab). Eventually, FDC die and follicular lysis occurs. From the pathogen perspective, binding to FDC is remarkably beneficial, bringing together virus and activated target cells that are highly susceptible to infection. Furthermore, FDC permit HIV to infect surrounding cells even in the presence of a vast excess of neutralizing Ab. Preliminary data suggest that FDC maintain virus infectivity-even when the virus cannot replicate. Thus retrovirus infection monopolizes FDC networks, thereby transforming the FDC Ag repository into a highly infectious retroviral reservoir.

Animals↗

PubMed1997

Chymopapain-induced reduction of proinflammatory phospholipase A2 activity and amelioration of neuropathic behavioral changes in an in vivo model of acute sciatica.

The mechanism of action underlying chymopapain (Chymodiactin) chemonucleolysis remains obscure. Radiographic studies suggest that chymopapain does not alter disc fragment size acutely; nonetheless, patients often report symptom resolution within a few days, even hours, of treatment. The authors postulate that, in addition to its chemonucleolytic action, chymopapain may possess antiinflammatory properties. To test this hypothesis, the authors assessed the ability of chymopapain to modulate the activity of the proinflammatory enzyme phospholipase A2 (PLA2) and to ameliorate behavioral changes associated with inflammatory neuropathy in an in vivo model of sciatica. Thirty-nine male Fischer rats were randomly assigned to one of three treatment groups: 1) saline, 2) betamethasone, or 3) chymopapain. All of the rats underwent unilateral sciatic nerve ligation with loose chromic gut suture to induce inflammatory mononeuropathy. The animals were tested for thermal and mechanical hyperalgesia on Days 0 (preoperation), 7 (pretreatment), and 14 (prior to death). Three animals were killed on Day 0 to determine the baseline PLA2 activity within unmanipulated rat sciatic nerves. On Day 7, three animals from each group were killed to assess PLA2 activity prior to treatment. The remainder were given a single infusion of saline, betamethasone (0.3 mg/kg), or chymopapain (100 pKat U) around the inflamed nerve. On Day 14, the remaining animals were killed and their sciatic nerves were removed. The tissue was homogenized and the PLA2 activity was determined using [14C]arachidonate-labeled Escherichia coli phospholipid membrane as a substrate. Lipids were extracted and separated by thin-layer chromatography. All animals developed behavioral changes consistent with inflammatory mononeuropathy 24 to 72 hours postoperatively; these included gait disturbance, flexion deformity, and hyperalgesia of the involved hindlimb. The degree of mechanical and thermal hyperalgesia was comparable between groups at Day 7. By Day 14, the thermal hyperalgesia had resolved; the mechanical hyperalgesia was less evident in the betamethasone- and chymopapain-treated groups than in the saline-treated controls (p = 0.003; saline- vs. chymopapain-treated groups p = 0.004; saline- vs. betamethasone-treated groups p = 0.008). The mean PLA2 activity at baseline (Day 0) was 11.6 +/- 4.9 nmol phospholipid hydrolyzed per minute per milligram of protein. The PLA2 activity at Day 7 was 74.4 +/- 18.2 (ligated side) and 21.2 +/- 11.7 (nonligated side). At Day 14, PLA2 activity was reduced in the chymopapain- (47.8 +/- 12.3) and betamethasone- (39.7 +/- 9.5) treated groups compared with the saline control group (62.3 +/- 11.2), (saline- vs. chymopapain-treated groups p < 0.05; saline- vs. betamethasone-treated groups p < 0.01). The PLA2 activity in nonligated specimens was 18.6 +/- 10.1. These data indicate that chymopapain exhibits antiinflammatory properties in vivo, reducing PLA2 activity and ameliorating mechanical hyperalgesia in this model of inflammatory sciatic neuropathy.

Acute Disease↗

PubMed1997

The early years of chiropractic in California: the people versus C.D. Greenall.

During the dawning years of the chiropractic profession, many of our brethren ventured forth to the fertile land of California to establish thriving practices and schools. These early pioneers practiced outside the laws of California, and many became subject to persecution by the authorities. With these persecutions came counter-attacks which shaped the future battles to be waged. Some of these counter-attacks were successful; most were not. These early laws and challenges influence our practice rights through the present and will continue to do so. C.D. Greenall, D.C., stood up to the medical authorities and won his case at the California Supreme Court fifteen years before the California electorate approved the Chiropractic Initiative Act in 1922.

Chiropractic↗

PubMed1997

Step treadmill exercise training and blood pressure reduction in women with mild hypertension.

Stepping as an exercise modality has gained increasing popularity. The step treadmill is an exercise machine which simulates actual stair-climbing. The purpose of this study was to determine the effectiveness of a 16-week supervised aerobic step treadmill exercise training protocol in reducing resting blood pressure in women with unmedicated mild hypertension. During the training protocol, subjects exercised during a self-selected appointment three times a week on the step treadmill, increasing from 20 minutes up to 60 minutes per session, at a target heart rate corresponding to 70-80% heart rate reserve for 16 weeks. Utilizing paired t-test analysis, mean resting systolic blood pressure decreased from 142.2 +/- 9.1 to 132.7 +/- 8.2 mm Hg (p < .01) and mean resting diastolic blood pressure decreased from 93 +/- 4.9 to 87.4 +/- 5.4 mm Hg (p < .01) during the 16-week protocol. Mean maximal oxygen uptake was significantly increased, whereas mean body weight did not change significantly over the 16-week period. Large scale trials are needed to further delineate the effectiveness of stepping as a health care intervention in adults with unmedicated mild hypertension, especially in women.

Adult↗

PubMed1996

Assessment of DNA adducts and the frequency of 6-thioguanine resistant T-lymphocytes in F344 rats fed 2,4-toluenediamine or implanted with a toluenediisocyanate-containing polyester polyurethane foam.

Toluenediamines have been of toxicological concern because of their industrial use as intermediates in polyurethane synthesis and because of the potential of their release from degradation of the Microthane polyesterurethane covering of some breast implants. In this study, we have assessed the extent of DNA damage in rats treated with a carcinogenic toluenediamine isomer, 2,4-toluenediamine (2,4-TDA), under conditions that result in tumor induction, and in rats implanted with Microthane polyesterurethane foam. Time and dose-dependent formation of adducts was observed in DNA from the liver and mammary gland of rats fed 10, 40, 80 and 180 ppm 2,4-TDA for up to 6 weeks. In assays conducted 1 to 32 weeks after the start of treatment, no adducts were detected in the DNA of T-lymphocytes isolated from the spleens of animals fed 40 or 180 ppm 2,4-TDA, nor was there an increase in mutations at the hprt locus in these lymphocytes. In rats fed 40 or 180 ppm, 2,4-TDA for 6 weeks, adducts were detectable in DNA isolated from liver and mammary gland for 26 to 43 weeks after termination of the treatment. No DNA damage, as assessed by both DNA adduct measurement and induction of T-lymphocyte hprt mutations, was observed in rats up to 42 weeks after receiving subcutaneous implants of polyesterurethane foam (67 or 267 mg/kg). Although 2,4-TDA is clearly capable of damaging DNA, the results of this study are consistent with the conclusion that Microthane foam-containing implants present a minimal risk of genotoxicity through release and subsequent metabolic activation of 2,4-TDA. The study also indicates that DNA adduct formation and mutation induction in lymphocytes are inadequate biomonitors for measuring exposure to toluenediamines.

Animals↗

PubMed1996

Regulation of renal sympathetic nerve activity at birth.

The present studies were designed to assess the contribution of onset of respiration, separation from the placenta, and a decrease in environmental temperature on the increase in renal sympathetic nerve activity (RSNA) that occurs at birth. In the first series of experiments, heart rate (HR), mean arterial blood pressure (MABP), and RSNA were recorded in chronically instrumented near-term fetal sheep (n = 12) before and during in utero ventilation (V), V + oxygenation (V + O), and V + O + umbilical cord occlusion (V + O + CO). RSNA increased by 49 +/- 16% during V alone (P < 0.05), whereas no additional changes were seen with V + O or V + O + CO. HR and MABP did not change with any intervention. In a second series of experiments (n = 10), changes in fetal HR, MABP, and RSNA in response to in utero cooling were recorded. Cooling of the fetal core temperature by -3.1 +/- 0.2 degree C produced a rapid and sustained increase in RSNA (330 +/- 155%), HR (25 +/- 11%), and MABP (10 +/- 2%) consistent with generalized sympathoexcitation. In a third series of studies (n = 3), we found that brain stem transection between the rostral pons and posterior hypothalamus abolishes the increases in RSNA seen at birth. These results suggest that cooling is a major contributor to the postnatal rise in RSNA and that brain centers at the level of or above the hypothalamus are involved in mediating sympathoexcitation at birth.

Animals↗

PubMed1996

Effectiveness of subgingival scaling and root planing: single versus multiple episodes of instrumentation.

This study evaluates the effectiveness of subgingival scaling and root planing comparing the effect of a single instrumentation to the effect of three instrumentations. A total of 35 teeth in 15 patients were selected; 15 were scaled once (Group A), 15 were scaled three times (Group B), and 5 were used as controls (Group C), representing teeth that were not instrumented. The Group A and B teeth were chosen in the same patient based on random selection. All the teeth were scored by the calculus index of the periodontal disease index. Six surface locations were probed to determine probing depth. The level of the gingival margin was marked on the teeth to locate supra- and subgingival calculus after extraction. The Group A and B teeth received the initial episode of scaling and root planing for not more than 10 minutes, then only the Group B teeth received two additional instrumentations of not more than 5 minutes each. The additional instrumentations were performed 24 hours after the initial scaling. The scaled and control teeth were extracted immediately after the third instrumentation period. The teeth were washed with water and stained with methylene blue. They were viewed under a stereomicroscope which had a tenth grid on its eyepiece. Assessments were made involving the total counts and percents of the surfaces covered with calculus on the scaled and unscaled teeth. The results demonstrated no significant difference in the effectiveness of calculus removal between single and multiple episodes of scaling and root planing. Similar results were found for the total amount of calculus removed, the calculus removed from individual surfaces, and the calculus removed from various probing depth levels.

Adult↗

PubMed1995

DNA adduct formation and T-lymphocyte mutation induction in F344 rats implanted with tumorigenic doses of 1,6-dinitropyrene.

Diesel emissions are known to induce tumors in experimental animals and are suspected of being carcinogenic in humans. Of the compounds associated with diesel exhaust, 1,6-dinitropyrene is a particularly potent mutagen and carcinogen. In these experiments, we have investigated the use of DNA adducts and T-lymphocyte mutations of 1,6-dinitropyrene as biomarkers for exposure to diesel emissions. 1,6-Dinitropyrene (0-150 micrograms) was applied directly to the lungs of male F344 rats according to a protocol known to induce lung tumors. In target (lung) and surrogate (liver, WBC, and spleen lymphocytes) tissues, one major DNA adduct, N-(deoxyguanosin-8-yl)-1-amino-6-nitropyrene, was detected by HPLC and/or 32P-postlabeling analyses. The levels of this adduct reached a maximum 1-7 days following treatment and decreased to 13-50% of the peak values by 28 days after dosing. In the lung, a 2-fold increase in dose resulted in a 2-fold increase in DNA binding up to the 30-micrograms dose; in the liver the same relationship was observed up to 10 micrograms 1,6-dinitropyrene. At higher doses, the extent of adduct formation still increased, but the rate was much lower than that occurring at lower doses. A limiting dilution clonal assay was used to measure mutation induction at the hypoxanthine-guanine phosphoribosyltranferase locus in spleen T lymphocytes. Following treatment, the mutant frequency increased until 21 weeks, remained constant until week 40, and then began to decrease. Mutant induction was dose related, with the increase in mutant frequency being significant at doses > or = 1 microgram 1,6-dinitropyrene. These data indicate that 1,6-dinitropyrene, a constituent of diesel emissions, is metabolically activated by nitroreduction to give DNA adducts in target and surrogate tissues. They further suggest that T-lymphocyte mutations may be a more sensitive and longer-lived biomarker than DNA adducts for assessing previous exposures to nitropolycyclic aromatic hydrocarbons.

Animals↗

PubMed1995

Analysis of in vivo mutation induced by N-ethyl-N-nitrosourea in the hprt gene of rat lymphocytes.

The rat lymphocyte hprt assay measures in vivo mutagenicity by quantifying the frequency of 6-thioguanine-resistant (TGr) spleen lymphocytes cultured in vitro. In this study we have examined the types of mutations induced in the hprt gene of TGr lymphocyte clones from female Fischer 344 rats exposed to 100 mg/kg N-ethyl-N-nitrosourea (ENU). Hprt exons 3 and 8 were amplified from DNA extracted from each of 249 clones, and the resulting products were screened for mutant:wild-type heteroduplex formation by denaturing gradient gel electrophoresis. The analysis revealed 59 clones with mutations in exon 3, and 20 clones with mutations in exon 8. DNA sequence analysis of the heteroduplexes identified 84 mutations: all of the mutations were base pair substitutions, and 88% were mutations of A:T base pairs. At least 82% were induced independently. These results suggest that the mutations found in TGr rat lymphocytes from ENU-treated rats were due mainly to ethylthymidine adducts. In addition, a comparison of these results with previously reported in vivo ENU mutational profiles indicates that the types of mutation detected by heteroduplex screening of rat hprt exons 3 and 8 are representative of mutation in the entire protein coding sequence.

Animals↗