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Biomedical subjects

Thomas J Smith

Publications and source records attributed to Thomas J Smith.

At least 19 recordsLinked to original sources
PubMed2026

Sustained effects of auricular point acupressure on chemotherapy-induced neuropathy: a randomized controlled trial follow-up study.

PURPOSE: Chemotherapy-induced neuropathy (CIN) is a persistent condition that impairs function and quality of life. Auricular point acupressure (APA) has shown short-term benefit for CIN, but the durability of these effects after treatment completion is unknown. This study evaluated the sustainability of symptom improvements for 3&#xa0;months following a 4-week APA intervention. METHODS: This prespecified secondary analysis of a randomized wait-list controlled trial compared mobile-supported APA (mAPA) and virtual APA (vAPA) in adults with moderate or greater CIN who received APA during the initial treatment phase (mAPA, n&#x2009;=&#x2009;80; vAPA, n&#x2009;=&#x2009;75). Outcomes at 1, 2, and 3&#xa0;months post-intervention were analyzed using generalized estimating equations with multiple imputation. The primary outcome was CIN severity, measured with an individualized composite outcome (ICO); the secondary outcome was CIN interference. RESULTS: Reductions in CIN severity and interference were maintained throughout follow-up in both groups (all p&#x2009;<&#x2009;.001). ICO scores decreased by 3.10, 3.36, and 3.61 points in mAPA and by 2.88, 2.90, and 3.21 points in vAPA at 1, 2, and 3&#xa0;months, respectively. Benefits were maintained post-treatment, with higher retention in the mAPA group. CONCLUSIONS: Improvements in CIN severity and interference after APA were sustained for up to 3&#xa0;months post-treatment, suggesting a durable benefit as a self-management strategy. Larger studies with longer follow-up and untreated comparison groups are needed. IMPLICATIONS FOR CANCER SURVIVORS: APA may offer survivors a durable, self-administered, nonpharmacologic option for managing CIN well beyond active treatment, without requiring ongoing clinical visits. TRIAL REGISTRATION: ClinicalTrials.gov, ID NCT04920097 registered on 3 June 2021.

Acupressure↗
PubMed2026

IgA is necessary and sufficient to prevent norovirus infection in mice.

Human norovirus is the leading cause of viral gastroenteritis, yet effective vaccines and therapeutics remain elusive. Using murine norovirus as a model, we found that mucosal immunoglobulin A (IgA) is both necessary and sufficient for protection against infection, whereas CD8+ T cells are dispensable. Robust intestinal IgA production requires at least 4 weeks of enteric infection, consistent with kinetics of human norovirus RNA clearance. Systemic vaccination elicits high titers of neutralizing serum IgG but fails to prevent enteric norovirus infection, phenocopying a recent human norovirus vaccine failure. In contrast, prophylactic delivery of dimeric anti-norovirus IgA via mRNA lipid nanoparticles confers sterilizing immunity. Together, these findings define a critical role for mucosal IgA in norovirus protection and identify IgA-based treatments as a therapeutic approach for human norovirus.

Animals↗
PubMed2025

Diversity and distribution of the lanthanome in aerobic methane-oxidising bacteria.

BACKGROUND: Lanthanides (Ln) play important and often regulatory roles in the metabolism of methylotrophs, including methanotrophs, particularly through their involvement in methanol oxidation. However, the diversity, distribution, and ecological relevance of Ln-associated proteins (the lanthanome) in aerobic methane-oxidising bacteria (MOB) remain underexplored. This study investigates the lanthanome using genome, plasmid, and proteome data, alongside metatranscriptome data from methane-rich lake sediments. RESULTS: We surveyed 179 genomes spanning Proteobacterial, Verrucomicrobial, and Actinobacterial MOBs to examine the distribution of Ln-dependent methanol dehydrogenases (MDHs) and Ln transport proteins. Distinct lineage-specific patterns were observed: XoxF5 was the most widespread MDH variant in Proteobacteria, while XoxF2 was restricted to Verrucomicrobia. Transporter systems also showed distinct&#xa0;patterns, with LanM restricted to Alphaproteobacteria, LanPepSY and LanA confined to Gammaproteobacteria, and LutH-like receptors broadly distributed across all lineages. Homologues of these genes were also detected on plasmids, indicating potential for horizontal gene transfer. In Lake Washington sediment metatranscriptomes, lanthanome transcripts were detected, with Proteobacteria as dominant contributors. Notably, a large fraction of xoxF transcripts were affiliated with non-MOB Methylophilaceae, consistent with known cooperative interactions with MOB. Using Methylosinus trichosporium OB3b as a model, we assessed methane oxidation and proteomic responses to soluble CeCl3 and a mixed-lanthanide ore. Lag phases were prolonged in the presence of lanthanides, particularly with ore, but methane oxidation rates converged across treatments after acclimation. Proteomic analysis revealed extensive condition-specific responses, with 724 proteins differentially expressed in Ore treatment compared to 60 under CeCl3. XoxF3 and XoxF5 were upregulated while MxaF and its accessory proteins were downregulated, consistent with the "lanthanide switch". Notably, LanM was not expressed despite being encoded, whereas LutH-like receptor was downregulated under both treatments, likely reflecting regulatory control to prevent excess metal uptake. Additional upregulation of a TonB-dependent receptor and ABC transporter suggests a potential lanthanophore-mediated uptake strategy. CONCLUSION: This study highlights the diversity and ecological activity of Ln-binding and transport systems in MOBs, their plasmid localisation and potential mobility, and their distinct regulation under different Ln sources. The strong proteomic response to complex ore underscores the physiological flexibility of MOBs in coping with natural lanthanide forms. These findings provide a framework for ecological studies and candidate targets for biotechnological applications in methane bioconversion and sustainable lanthanide recovery from complex materials.

Horizontal gene transfer↗
PubMed2004

Lumpectomy plus tamoxifen with or without irradiation in women 70 years of age or older with early breast cancer.

BACKGROUND: In women 70 years of age or older who have early breast cancer, it is unclear whether lumpectomy plus tamoxifen is as effective as lumpectomy followed by tamoxifen plus radiation therapy. METHODS: Between July 1994 and February 1999, we randomly assigned 636 women who were 70 years of age or older and who had clinical stage I (T1N0M0 according to the tumor-node-metastasis classification), estrogen-receptor-positive breast carcinoma treated by lumpectomy to receive tamoxifen plus radiation therapy (317 women) or tamoxifen alone (319 women). Primary end points were the time to local or regional recurrence, the frequency of mastectomy for recurrence, breast-cancer-specific survival, the time to distant metastasis, and overall survival. RESULTS: The only significant difference between the two groups was in the rate of local or regional recurrence at five years (1 percent in the group given tamoxifen plus irradiation and 4 percent in the group given tamoxifen alone, P<0.001). There were no significant differences between the two groups with regard to the rates of mastectomy for local recurrence, distant metastases, or five-year rates of overall survival (87 percent in the group given tamoxifen plus irradiation and 86 percent in the tamoxifen group, P=0.94). Assessment by physicians and patients of cosmetic results and adverse events uniformly rated tamoxifen plus irradiation inferior to tamoxifen alone. CONCLUSIONS: Lumpectomy plus adjuvant therapy with tamoxifen alone is a realistic choice for the treatment of women 70 years of age or older who have early, estrogen-receptor-positive breast cancer.

Aged↗
PubMed2004

Differential antifungal and calcium channel-blocking activity among structurally related plant defensins.

Plant defensins are a family of small Cys-rich antifungal proteins that play important roles in plant defense against invading fungi. Structures of several plant defensins share a Cys-stabilized alpha/beta-motif. Structural determinants in plant defensins that govern their antifungal activity and the mechanisms by which they inhibit fungal growth remain unclear. Alfalfa (Medicago sativa) seed defensin, MsDef1, strongly inhibits the growth of Fusarium graminearum in vitro, and its antifungal activity is markedly reduced in the presence of Ca(2+). By contrast, MtDef2 from Medicago truncatula, which shares 65% amino acid sequence identity with MsDef1, lacks antifungal activity against F. graminearum. Characterization of the in vitro antifungal activity of the chimeras containing portions of the MsDef1 and MtDef2 proteins shows that the major determinants of antifungal activity reside in the carboxy-terminal region (amino acids 31-45) of MsDef1. We further define the active site by demonstrating that the Arg at position 38 of MsDef1 is critical for its antifungal activity. Furthermore, we have found for the first time, to our knowledge, that MsDef1 blocks the mammalian L-type Ca(2+) channel in a manner akin to a virally encoded and structurally unrelated antifungal toxin KP4 from Ustilago maydis, whereas structurally similar MtDef2 and the radish (Raphanus sativus) seed defensin Rs-AFP2 fail to block the L-type Ca(2+) channel. From these results, we speculate that the two unrelated antifungal proteins, KP4 and MsDef1, have evolutionarily converged upon the same molecular target, whereas the two structurally related antifungal plant defensins, MtDef2 and Rs-AFP2, have diverged to attack different targets in fungi.

Amino Acid Sequence↗
PubMed2004

Assessment of optimal size and composition of the U.S. National Registry of hematopoietic stem cell donors.

BACKGROUND: The National Marrow Donor Program (NMDP) receives federal funding to operate a registry of over 4 million volunteer donors for patients in need of a hematopoietic stem cell transplant. Because minority patients are less likely to find a suitably matched donor than whites, special efforts have been aimed toward recruitment of minorities. Significant financial resources are required to recruit and tissue type additional volunteer donors. METHODS: Population genetics models have been constructed to project likelihoods of finding a human leukocyte antigen (HLA)-matched donor for patients of various racial/ethnic groups. These projections have been made under a variety of strategies for expansion of the NMDP Registry. Cost-effectiveness calculations incorporated donor unavailability and other barriers to transplantation. RESULTS: At current recruitment rates, the probability of an available HLA-A,B,DRB1 matched donor is projected to increase from 27% to 34%; 45% to 54%; 75% to 79%; and 48% to 55%, for blacks, Asians/Pacific Islanders, whites and Hispanics, respectively, by the year 2007. Substantial increases in minority recruitment would have only modest impacts on these projections. These projections are heavily affected by donor availability rates, which are less than 50% for minority volunteers. CONCLUSIONS: Continued recruitment of additional volunteers can improve the likelihood of finding an HLA-matched donor, but will still leave significant numbers of patients of all racial/ethnic groups without a match. Efforts to improve donor availability (especially among minorities) and to increase the number of patients with access to the NMDP Registry may prove to be more cost-effective means of increasing transplants.

Genetics, Population↗
PubMed2004

American Society of Clinical Oncology recommendations for the initial hormonal management of androgen-sensitive metastatic, recurrent, or progressive prostate cancer.

PURPOSE: To develop a clinical practice guideline for the management of men with metastatic, recurrent, or progressive carcinoma of the prostate. The focus of this document is on the use, combinations, and timing of various forms of androgen deprivation therapy (ADT) for the palliation of men with androgen-sensitive disease. METHODS: An expert panel and writing committee were formed. The questions to be addressed by the guideline were determined, and a systematic review of the literature was performed, which included a search of online databases, bibliographic review, and consultation with content experts. A priori criteria were used to select studies for analysis and study authors were contacted when necessary. RESULTS: There were 10 randomized controlled trials, six systematic reviews, and one Markov model available to inform the guidelines. CONCLUSION: A full discussion between practitioner and patient should occur to determine which therapy is best for the patient. Bilateral orchiectomy or luteinizing hormone releasing hormone agonists are the recommended initial treatments. Nonsteroidal antiandrogen therapy may be discussed as an alternative, but steroidal antiandrogens should not be offered as monotherapy. Patients willing to accept the increased toxicity of combined androgen blockage for a small benefit in survival should be offered nonsteroidal antiandrogen in addition to castrate therapy. Until data from studies using modern medical diagnostic/biochemical tests and standardized follow-up schedules become available, no specific recommendations can be issued regarding the question of early versus deferred ADT. A discussion about the pros and cons of early versus deferred ADT should occur.

Antineoplastic Agents, Hormonal↗
PubMed2004

Vehicle traffic as a source of particulate polycyclic aromatic hydrocarbon exposure in the Mexico City metropolitan area.

Surface properties of aerosols in the Mexico City metropolitan area have been measured in a variety of exposure scenarios related to vehicle emissions in 2002, using continuous, real-time instruments. The objective of these experiments is to describe ambient and occupational particulate polycyclic aromatic hydrocarbon (PAH) concentrations associated with vehicular traffic and facilities using diesel vehicles. Median total particulate PAH concentrations along Mexico City's roadways range from 60 to 910 ng m(-3), averaged over a minimum of 1 h. These levels are approximately 5 times higher than concentrations measured in the United States and among the highest measured ambient values reported in the literature. The ratio of particulate PAH concentration to aerosol active surface area is much higher along roadways and in other areas of fresh vehicle emissions, compared to ratios measured at sites influenced more by aged emissions or noncombustion sources. For particles freshly emitted by vehicles, PAH and elemental carbon (EC) concentrations are correlated because they both originate during the combustion process. Comparison of PAH versus EC and active surface area concentrations at different locations suggests that surface PAH concentrations may diminish with particle aging. These results indicate that exposure to vehicle-related PAH emissions on Mexico City's roadways may present an important public health risk.

Aerosols↗
PubMed2004

Structure of Cowpea mottle virus: a consensus in the genus Carmovirus.

Cowpea mottle virus (CPMoV) is a T = 3 virus that belongs to Carmovirus genus of the Tombusviridae family. Here, we report the crystal structure of CPMoV determined to a resolution of 7.0 angstroms. The structures and sequences of three Carmoviruses, CPMoV, Turnip crinkle virus (TCV), and Carnation mottle virus (CarMV) have been compared to TBSV from the Tombusvirus genus. CPMoV, TCV, and CarMV all have a deletion in betaC strand in the S domain relative to TBSV that may be distinctive to the genus. Although CPMoV has an elongated C-terminus like TBSV, it does not interact with the icosahedrally related P domain as observed in TBSV. In CPMoV, the termini of A and B interact with the icosahedrally related shell domains of A and C, respectively, to form a chain of interactions around the 5-fold axes. The C subunit terminus does not, however, interact with the B subunit because of quasi-equivalent differences in the P domain orientations.

Amino Acid Sequence↗
PubMed2004

Pain management, including intrathecal pumps.

Even when managed according to guidelines, approximately 14% of cancer patients have unrelieved pain or unacceptable side effects, and there is good evidence that patients still are not receiving optimal therapy. Implantable drug delivery systems (IDDS) administer small amounts of drugs directly to the spinal cord and reduce systemic narcotic exposure by a factor of 300 to one. In a large randomized trial of 202 patients with pain scores of 7.5 or higher, despite 200 mg or more of morphine or equivalent narcotics, IDDS gave better clinical success than comprehensive medical management (84.5% vs 70.8%, P=0.05). Pain scores were reduced by 52% versus 39%, drug toxicity scores were reduced by 50% versus 17%, and IDDS patients lived longer. Even the most refractory pain patients--those failed by a month of comprehensive medical management by experts--when subsequently provided with IDDS, had a 27% reduction in pain scores and a 50% reduction in drug side effects. Given multiple positive small cohort studies and a positive high-power randomized trial, IDDS should be considered as the best treatment for this population.

Analgesics, Opioid↗
PubMed2004

Massive hydromorphone dose delivered subcutaneously instead of intrathecally: guidelines for prevention and management of opioid, local anesthetic, and clonidine overdose.

Increasing numbers of patients with refractory pain are receiving intrathecal drug delivery systems (IDDS). We describe a case to illustrate the clinical manifestations and management implications of inadvertent overdose with drugs used in IDDS, including opioids, clonidine, baclofen, and local anesthetics. An IDDS patient received a bimonthly dose of intrathecal hydromorphone subcutaneously. The patient received a total of 540 mg hydromorphone into the subcutaneous pocket around the intrathecal pump. She was treated with naloxone intravenously over 12 hours, and had no major adverse sequelae. Such occurrences may happen more frequently with the expanded use of IDDS and clinicians should be prepared to take quick action. Counteracting an opioid with naloxone until the opioid is metabolized and excreted can be done safely. Inadvertent subcutaneous administration of other types of drugs could be more difficult to manage.

Adult↗
PubMed2004

Historical cohort study of U.S. man-made vitreous fiber production workers IX: summary of 1992 mortality follow up and analysis of respiratory system cancer among female workers.

We report the 1946-1992 mortality experience of 4008 females employed in any of 10 U.S. fiberglass manufacturing plants between 1945 and 1978 relative to external population rates. We also examine respiratory system cancer (RSC) mortality as a function of estimated exposure to respirable fibers (RFib), formaldehyde (FOR), silica, phenolics, urea, and other agents based on internal cohort comparisons. No statistically significantly elevated standardized mortality ratios were observed for all-cause mortality (930 deaths), any of the 25 nonmalignant causes considered, all malignant neoplasms (266 deaths), or any of the 27 malignant causes considered. Internal cohort comparisons revealed no significant positive associations between RSC mortality (53 cases) and exposure to RFib, FOR, or any of the other agents considered, although exposure levels were generally low. Some demographic subgroups appear to be at relatively increased risk of RSC.

Adult↗
PubMed2004

A nested case-control study of prostate cancer and atrazine exposure.

Elevated prostate cancer incidence was found at a plant producing atrazine that had an intensive prostate screening program. This study tested the relationship among atrazine exposure, prostate cancer, and the screening program. Twelve cases and 130 control subjects were selected from the original cohort. Prostate screening and occupational histories were abstracted from company records and atrazine exposures were estimated. Hire date was comparable for cases and control subjects. Nearly half of the control subjects and no cases left before the prostate-specific antigen (PSA) screening program. Cases had more PSA tests than control subjects (odds ratio for > or =1 test, 8.54; 95% confidence interval, 1.69-82.20). There was no association between atrazine exposure and prostate cancer when those with > or =1 test were compared. There was no evidence for an association between atrazine and prostate cancer.

Atrazine↗
PubMed2004

Dose-ranging trial with a recombinant urokinase (urokinase alfa) for occluded central venous catheters in oncology patients.

PURPOSE: Recombinant urokinase (r-UK) is a high-molecular-weight urokinase produced in transfected, non-human, mammalian cells. A Phase II, randomized, double-blind, parallel, placebo-controlled, dose-ranging study was performed to compare the safety and efficacy of one or two instillations of three intraluminal concentrations of r-UK (5,000; 15,000; and 25,000 IU/mL) with a placebo for reestablishment of total function to occluded central venous access devices (CVADs). MATERIALS AND METHODS: One-hundred eight patients with CVAD withdrawal or total occlusion were enrolled and randomized to treatment; 104 patients received at least one instillation of study drug and 101 patients completed treatment. All but one patient had cancer. RESULTS: All three concentrations of r-UK were significantly superior to placebo in restoring total CVAD function (patency of all occluded lumens) after one or two instillations of study medication (25,000 IU/mL r-UK, 68% vs. placebo, 28% [P =.007]; 15,000 IU/mL r-UK, 69% vs. placebo, 24% [P =.004]; 5,000 IU/mL r-UK, 70% vs. placebo, 28% [P =.003]). Comparisons of the three r-UK concentrations indicated no difference after one or two instillations with regards to patency restoration. Treatment-emergent hemorrhagic events occurring within 72 hours after study drug exposure were experienced by four patients (17%) in the 25,000 IU/mL r-UK group, two patients (7%) in the 15,000 IU/mL r-UK group, no patients in the 5,000 IU/mL r-UK group, and no patients in the placebo group. CONCLUSIONS: Efficacy and safety results of this study support further evaluation of a 5,000 IU/mL concentration of r-UK for treatment of occluded CVADs in adult and pediatric patients from 1 year of age.

Adolescent↗
PubMed2004

Formaldehyde dehydrogenase preparations from Methylococcus capsulatus (Bath) comprise methanol dehydrogenase and methylene tetrahydromethanopterin dehydrogenase.

In methylotrophic bacteria, formaldehyde is an important but potentially toxic metabolic intermediate that can be assimilated into biomass or oxidized to yield energy. Previously reported was the purification of an NAD(P)(+)-dependent formaldehyde dehydrogenase (FDH) from the obligate methane-oxidizing methylotroph Methylococcus capsulatus (Bath), presumably important in formaldehyde oxidation, which required a heat-stable factor (known as the modifin) for FDH activity. Here, the major protein component of this FDH preparation was shown by biophysical techniques to comprise subunits of 64 and 8 kDa in an alpha(2)beta(2) arrangement. N-terminal sequencing of the subunits of FDH, together with enzymological characterization, showed that the alpha(2)beta(2) tetramer was a quinoprotein methanol dehydrogenase of the type found in other methylotrophs. The FDH preparations were shown to contain a highly active NAD(P)(+)-dependent methylene tetrahydromethanopterin dehydrogenase that was the probable source of the NAD(P)(+)-dependent formaldehyde oxidation activity. These results support previous findings that methylotrophs possess multiple pathways for formaldehyde dissimilation.

Alcohol Oxidoreductases↗
PubMed2004

Phase II study of cisplatin and 5-fluorouracil (PF) and mitomycin C, vincristine, cisplatin and 5-fluorouracil (MVPF) in patients with metastatic large bowel cancer: an Eastern Cooperative Oncology Group study (EST 1285).

PURPOSE: To compare the efficacy and the toxicity of cisplatin and 5-fluorouracil (PF) and mitomycin C, vincristine, cisplatin and 5-fluorouracil (MVPF) in patients with metastatic large bowel cancer. PATIENTS AND METHODS: A total of 94 patients with no prior chemotherapy and measurable metastatic large bowel cancer were randomly assigned to one of the two treatment regimens. Eastern Cooperative Oncology Group (ECOG) criteria were used to evaluate response and toxicity. RESULTS: Fifty patients were randomized to PF and 44 to MVPF. Toxicity was evaluable in all patients except one; response was evaluable in 40 and 31, with response rate of 13 and 42%, respectively. Intent-to-treat analysis showed a response rate of 12 and 32%, respectively (p = 0.076), where it was assumed that none of the ineligible or unevaluable patients responded. Median survival for all patients was 9 months, with no difference between PF and MVPF. ECOG Performance Status (0 vs. 1), weight loss (< or =10 vs. >10%) and site of metastatic lesion had statistically significant impact on survival. MVPF was definitely more toxic than PF (p < 0.000005). CONCLUSION: Both treatment regimens showed clinical activity. The MVPF regimen resulted in more responses than PF, no improvement in survival, and more toxicity.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Structural determinants of metal specificity in the zinc transport protein ZnuA from synechocystis 6803.

A number of bacterial metal transporters belong to the cluster 9 family of ABC transporters. The residues in the periplasmic domain thought to be involved in metal binding seem highly conserved and yet the transporters have varying metal specificity. To solve this seeming paradox and ascertain how metal specificity is exacted, the structure of ZnuA, the periplasmic domain of a zinc transporter from Synechocystis 6803, has been determined to a resolution of 1.9A. In previously determined structures of homologous proteins, four residues chelate the bound metal. From sequence alignments of the cluster 9 metal transporters, the fourth residue in this metal-binding site, an aspartate, is also present in the appropriate position in the ZnuA sequence. However, this result is misleading, since our structural data indicate that zinc binds via only three histidine residues and the aspartate is replaced by a large hydrophobic cavity. We propose that ZnuA binds zinc over manganese by providing only three ligating residues. ZnuA has a highly charged and mobile loop that protrudes from the protein in the vicinity of the metal-binding site. Similar loops are found in other types of zinc transporters but not manganese transporters. Therefore, we propose that the function of this domain is to act as a zinc chaperone to facilitate acquisition. Therefore, while Mn2+ transporters can bind Zn2+ in vitro they may not be able to acquire it in vivo without this structure because of the low concentration of free Zn2+.

Amino Acid Sequence↗