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Biomedical subjects

D Archer

Publications and source records attributed to D Archer.

At least 19 recordsLinked to original sources
PubMed2026

Exploring the perceptions, experiences, and behaviours that nurses and midwives face in relation to sleep: A systematic review of qualitative evidence.

BACKGROUND: The importance of sleep for nurses and midwives is increasingly being recognised. Poor sleep is known to have negative impacts on physical health, mental wellbeing, and work performance. This has prompted efforts to promote and support staff sleep. However, further efforts are needed to understand how nurses and midwives consider and manage sleep to ensure that meaningful and effective interventions are adopted and sustained. AIMS: This review of qualitative evidence aims to examine nurses' and midwives' perceptions, experiences, and behaviours around sleep. METHODS: This review followed JBI's systematic meta-aggregative approach including development of an a priori protocol. A systematic search of six electronic databases (MEDLINE, Embase, Emcare, PsycINFO, CINAHL, and Scopus) was undertaken to identify qualitative studies that examine nurses' and midwives' perceptions, experiences, and behaviours related to sleep. The search was conducted on the 10th of October 2024. Study selection, quality appraisal, data extraction, and synthesis followed JBI approaches and the ConQual approach was used to report assessment of synthesised findings. RESULTS: Thirty-three studies were included for review, and 245 findings were aggregated into 24 categories and nine synthesised findings related to the perceptions, behaviours, and experiences. While sleep was perceived as important, poor sleep was often understood as an expected and inevitable part of the job and that there was a need to always be awake to provide continual care. Experiences influencing sleep related to personal circumstances and work-related factors, as well as professional training and institutional practices. A range of behaviours, including planning time to sleep, using sleep aids, modifying the sleep environment, and altering daytime behaviours were also described. CONCLUSION: This review identified a range of perceptions, behaviours, and experiences that may influence the sleep of nurses and midwives which are vital to supporting individual and workforce wellbeing and safe, effective clinical practice. Insights from this review can be used to better understand nurses' and midwives' relationship with sleep and to develop and enhance targeted sleep interventions and programs that aim to promote and support healthy sleep among nurses and midwives. Open Science Framework Registration: 10.17605/OSF.IO/F32UM.

Humans↗
PubMed2006

The uncertainty of the surgical margin in the treatment of head and neck cancer.

We discuss our surgical philosophy concerning the subtle interplay between the size of the surgical margin taken and the resultant morbidity from ablative oncological procedures, which is ever more evident in the treatment of head and neck malignancy. The extent of tissue resection is determined by the "trade off" between cancer control and the perioperative, functional and aesthetic morbidity and mortality of the surgery. We also discuss our dilemmas concerning recent minimally invasive endoscopic microsurgical techniques for the trans-oral laser removal or co-ablation of aero-digestive tract tumours, which result in a minimal surgical margin of oncological clearance. By a process of inductive argument as to the nature of the surgical margin, we consider whether the risks of taking a lesser margin with adjuvant therapy is justified by the attendant gain in reduced surgical morbidity and the possible costs in tumour control.

Head and Neck Neoplasms↗
PubMed2005

Association between polymorphisms of the GPX1 gene and second primary tumours after index squamous cell cancer of the head and neck.

We investigated the association between genetic polymorphisms in GPX1 gene amongst patients who had index squamous cell carcinoma (SCCHN) and a second primary tumour (SPT) after a primary SCCHN in a case-control study. GPX1 genotypes were determined for 61 patients with SPT and for 259 control subjects by a PCR technique using a fluorescent-labelled primer. Analysis was by an ABI automated fluorescent sequencer. The associations between specific genotypes and the development of SPT were examined by logistic regression. A significant difference was found between the control group and the SPT cases in allele frequencies of GPX1 ALA( *)6 and ALA( *)7 (p(trend)=0.04). These results suggest that polymorphisms in the GPX1 gene may be a marker for SPT development and further studies are indicated.

Adult↗
PubMed2003

Mucosal malignant melanoma of the head and neck: the Marsden experience over half a century.

We reviewed patients treated at The Royal Marsden Hospital for mucosal malignant melanoma of the head and neck between 1945 and 1996. The analysis included 89 patients, and this study is the largest so far reported from a single institution in the literature. The overall 5-year survival rate for the patient population was 23% (95% confidence interval: 14-33) and the 10-year survival rate was 12%, (6-21%). The only significant predictor of survival was the tumour stage at presentation. Radical local excision was the only treatment that provided a chance of cure. Adding radiotherapy to surgery in tumours that could be radically excised did not confer any statistically significant advantage in reducing local recurrence or improving survival.

Adult↗
PubMed2003

Tumour thickness predicts cervical nodal metastases and survival in early oral tongue cancer.

Squamous cell carcinoma (SCC) of the oral tongue is characterized by a high propensity for cervical nodal metastasis, which affects the probability of regional control and survival. Until now, elective treatment of the clinically negative neck in early lesions (T(1-2)) of the oral tongue cancer remains controversial. This study attempted to identify predictive factor(s) for cervical nodal metastasis and treatment outcomes in patients with early stage SCC of the oral tongue treated primarily by surgery. Fifty patients with previously untreated Stage I/II primary tongue carcinomas with available archival specimens treated at the Royal Marsden Hospital between 1981 and 1998 were reviewed. Clinico-pathological features including age, gender, alcohol and tobacco consumption, tumour location, histological grade, tumour-stromal border, growth pattern, tumour thickness, and clinical stage were evaluated and the correlations with cervical metastases and outcome analysis were determined. The overall occult nodal metastatic rate was 40% (20/50). Tumour thickness exceeding 5 mm was statistically significantly correlated with cervical metastases (P = 0.003; relative risk = 2.429). No statistical correlation was observed between other clinico-pathological parameters and nodal metastasis. With a median follow-up of 98 months, 5-year actuarial overall, disease-specific (DSS), and relapse-free survival were 65.71, 67.77, and 68.18%, respectively. Univariate analysis for DSS showed poorer outcomes for patients with age > 60 years (P = 0.0423) and tumour thickness > 5 mm (P = 0.0067). The effect of tumour thickness was maintained (P = 0.005) on multivariate analysis. The present study indicates that the thickness of primary tumour has a strong predictive value for occult cervical metastasis and poor outcomes in patients with Stage I/II oral tongue SCC. Thus, elective neck treatment (surgery or irradiation) is indicated for tumours exceeding 5 mm thickness.

Adult↗
PubMed2001

Factors affecting microbial formation of nitrate-nitrogen in soil and their effects on fertilizer nitrogen use efficiency.

Mineralization of soil organic matter is governed by predictable factors with nitrate-N as the end product. Crop production interrupts the natural balance, accelerates mineralization of N, and elevates levels of nitrate-N in soil. Six factors determine nitrate-N levels in soils: soil clay content, bulk density, organic matter content, pH, temperature, and rainfall. Maximal rates of N mineralization require an optimal level of air-filled pore space. Optimal air-filled pore space depends on soil clay content, soil organic matter content, soil bulk density, and rainfall. Pore space is partitioned into water- and air-filled space. A maximal rate of nitrate formation occurs at a pH of 6.7 and rather modest mineralization rates occur at pH 5.0 and 8.0. Predictions of the soil nitrate-N concentrations with a relative precision of 1 to 4 microg N g(-1) of soil were obtained with a computerized N fertilizer decision aid. Grain yields obtained using the N fertilizer decision aid were not measurably different from those using adjacent farmer practices, but N fertilizer use was reduced by >10%. Predicting mineralization in this manner allows optimal N applications to be determined for site-specific soil and weather conditions.

Agriculture↗
PubMed2001

Alcohol oxidase is a novel pathogenicity factor for Cladosporium fulvum, but aldehyde dehydrogenase is dispensable.

Cladosporiumfulvum is a mitosporic ascomycete pathogen of tomato. A study of fungal genes expressed during carbon starvation in vitro identified several genes that were up regulated during growth in planta. These included genes predicted to encode acetaldehyde dehydrogenase (Aldh1) and alcohol oxidase (Aox1). An Aldh1 deletion mutant was constructed. This mutant lacked all detectable ALDH activity, had lost the ability to grow with ethanol as a carbon source, but was unaffected in pathogenicity. Aox1 expression was induced by carbon starvation and during the later stages of infection. The alcohol oxidase enzyme activity has broadly similar properties (Km values, substrate specificity, pH, and heat stability) to yeast enzymes. Antibodies raised to Hansenula polymorpha alcohol oxidase (AOX) detected antigens in Western blots of starved C. fulvum mycelium and infected plant material. Antigen reacting with the antibodies was localized to organelles resembling peroxisomes in starved mycelium and infected plants. Disruption mutants of Aox1 lacked detectable AOX activity and had markedly reduced pathogenicity as assayed by two different measures of fungal growth. These results identify alcohol oxidase as a novel pathogenicity factor and are discussed in relation to peroxisomal metabolism of fungal pathogens during growth in planta.

Alcohol Oxidoreductases↗
PubMed2001

Silicone oil-intraocular lens interaction: which lens to use?

AIM: To determine a suitable intraocular lens for implantation in patients at high risk of lens exposure to silicone oil in their lifetime. METHODS: PMMA, AcrySof, AR40, AQUA-Sense, and Raysoft lenses were examined. Each lens was immersed for 5 minute intervals in balanced salt solution (BSS), in stained silicone oil, and again in BSS before being photographed in air and in BSS. Percentage silicone oil coverage of the lens optic was determined. RESULTS: The mean percentage coating (MPC) for the lens biomaterials ranged from 5.2% to 21.5%. The Raysoft lens had significantly less oil coverage when statistically compared with the other lens types (p < 0.001). CONCLUSION: A Raysoft (Rayner) lens is a suitable lens for implantation in patients who are at risk of severe vitreoretinal disease.

Adhesiveness↗
PubMed2000

A randomized comparison of the effects on vaginal and cervical epithelium of a placebo vaginal ring with non-use of a ring.

Little is known about the effects of contraceptive vaginal rings on the vaginal surface epithelium, although most studies have not demonstrated any significant deleterious effect. However, one study found that some medium-to-long-term levonorgestrel-releasing ring users developed chronic erythematous and ulcerative lesions in the posterior vaginal fornix. Subsequently, this ring was completely redesigned (IVR-2) with different dimensions and much greater flexibility. The first version of IVR-2 was designed as a placebo ring to explore effects on the vagina and cervix without addition of a progestogen. One-hundred-sixty-six healthy sexually active women volunteers were recruited in four centers and randomly assigned for 6 months to either placebo ring use or control (non-use) using a predetermined randomization code generated by WHO in a 2:1 ratio. Careful inspections of the vaginal and cervical epithelium were performed with a colposcope at admission and at 2-month intervals. No clinically significant lesions were detected in any center either among ring users or controls. However, a number of minor changes in appearance of the vaginal and cervical epithelium (erythema, petechiae, ecchymosis, and minor aceto-white changes) were described from the Sydney Center, some of which were present on admission and some of which were found on subsequent examination. Ten of eleven "red" changes on the cervix and vagina were noted in IVR-2 users, and only one in the controls, suggesting a contribution by the IVR-2 to minor epithelial surface changes. Five of ten resolved completely with continued ring use. There was no correlation in this study between epithelial changes and cigarette smoking or frequency of intercourse in the 14 days prior to colposcopic examination but a significant relationship between tampon use in the last 7 days and all epithelial changes (p = 0.05) and especially red changes (p = 0. 027) was noted. Red changes were significantly less likely to be found among condom users (p = 0.007). The IVR-2 placebo ring did not produce clinically significant changes in the vaginal epithelium and cervical mucosa and a carefully controlled and randomized study should be considered to compare the epithelial appearances in women using a placebo IVR-2 and one releasing 20 microg levonorgestrel.

Biopsy↗
PubMed1999

Geochemical consequences of increased atmospheric carbon dioxide on coral reefs

A coral reef represents the net accumulation of calcium carbonate (CaCO3) produced by corals and other calcifying organisms. If calcification declines, then reef-building capacity also declines. Coral reef calcification depends on the saturation state of the carbonate mineral aragonite of surface waters. By the middle of the next century, an increased concentration of carbon dioxide will decrease the aragonite saturation state in the tropics by 30 percent and biogenic aragonite precipitation by 14 to 30 percent. Coral reefs are particularly threatened, because reef-building organisms secrete metastable forms of CaCO3, but the biogeochemical consequences on other calcifying marine ecosystems may be equally severe.

Journal Article↗
PubMed1999

Comparison of 0.25 mg and 0.1 mg intrathecal morphine for analgesia after Cesarean section.

PURPOSE: To test the hypothesis that 0.1 mg intrathecal morphine plus NSAIDs provides satisfactory analgesia post-Cesarean section with fewer side effects than 0.25 mg intrathecal morphine. METHODS: Sixty women, scheduled for elective Cesarean section under spinal anesthesia, were randomized to receive either 0.1 mg or 0.25 mg intrathecal morphine combined with hyperbaric bupivacaine 0.75% and 20 microg fentanyl. All patients received a 100 mg indomethacin suppository at the end of surgery and 500 mg naproxen p.o. b.i.d. was started the evening of surgery and continued until discharge. A blinded researcher recorded the pain, pruritus, and nausea scores, the time to first request for additional analgesics, a visual analogue scale (VAS) satisfaction score, and the use of additional opioids, antipruritics, and/or antiemetics. RESULTS: Of the 60 patients enrolled, two were not included in the data analysis because of protocol violations leaving 30 patients in the 0.1 mg group and 28 in the 0.25 mg group. There were no differences in the VAS pain scores or the number of women requesting an opioid other than codeine between the two groups. The VAS pruritus scores in the 0.1 mg group were lower throughout the 24 hr (P < 0.001). Fewer women in the 0.1 mg group (4/30 vs 12/28) requested nalbuphine to treat itching (P = 0.018). Nausea scores were lower in the 0.1 mg group (P < 0.001). CONCLUSION: The use of 0.1 mg intrathecal morphine plus NSAIDs provides analgesia of similar quality to 0.25 mg but with fewer undesirable side effects following Cesarean section.

Adult↗
PubMed1999

Plant low-molecular-weight phospholipase A2S (PLA2s) are structurally related to the animal secretory PLA2s and are present as a family of isoforms in rice (Oryza sativa).

Recently, we purified to homogeneity and characterized a low-molecular-weight calcium-dependent phospholipase A2 (PLA2) from developing elm seed endosperm. This represented the first purified and characterized PLA2 from a plant tissue. The full sequences of two distinct but homologous rice (Oryza sativa) cDNAs are given here. These encode mature proteins of 1 19 amino acids (PLA2-I, preceded by a 19 amino acid signal peptide) and 128 amino acids (PLA2-II. preceded by a 25 amino acid signal peptide), and were derived from four expressed sequence tag (EST) clones. Both proteins were homologous to the N-terminal amino acid sequence of the elm PLA2. They contained twelve conserved cysteine residues and sequences that are likely to represent the Ca(2+)-binding loop and active-site motif, which are characteristic of animal secretory PLA2s. A soluble PLA2s activity was purified 145 000-fold from green rice shoots. This had the same biochemical characteristics as the elm and animal secretory PLA2s. The purified rice PLA2 consisted of two proteins, with a molecular weight of 12 440 and 12 920, that had identical N-terminal amino acid sequences. This sequence was different from but homologous to the PLA2-I and PLA2-II sequences. Taken together, the results suggest that at least three different low-molecular-weight PLA2s are expressed in green rice shoots. Southern blot analysis suggested that multiple copies of such genes are likely to occur in the rice and in other plant genomes.

Amino Acid Sequence↗
PubMed1998

Medicare choices.

There are new choices for Medicare beneficiaries, and individuals may be confused about what is available to them. Home care providers who understand these choices can be valuable resources to clients as well as to colleagues.

Aged↗
PubMed1997

Cisplatin and 5-fluorouracil for symptom control in advanced salivary adenoid cystic carcinoma.

Adenoid cystic carcinoma is a relatively rare tumour which arises in the parotid and submandibular salivary glands. Initial management is surgical, often with post-operative radiotherapy, but local relapse is common and distant metastasis not infrequent. Chemotherapy is generally reserved for cases where symptoms are not controlled by other means, since the tumour is slow growing and the response rate frequently disappointing. Cisplatin and 5-fluorouracil (5-FU) both show single agent activity in this disease but had not been previously investigated in combination. All patients referred for palliative chemotherapy of metastatic, symptomatic, histologically confirmed adenoid cystic carcinoma between November 1990 and February 1994 were considered for this study. The drugs were administered as follows: cisplatin 100 mg/m2 with appropriate pre- and post-hydration and 5-FU on a 4-day schedule of 1 g/m2/day. A total of 11 patients (7 male, 4 female) with median age 53 years (range 34-69) received 46 courses of chemotherapy (median four, range one to six). All patients had prior surgery and 8 had previously received radiotherapy. There were no objective responses of > 50% reduction in tumour size. 3 patients had a minor response and two progressed on treatment. The symptomatic response rate, however, was 64%, which compares favourably with other previously reported regimens. Toxicity was manageable. The median time to tumour progression was 9 months (range 0-38) and median survival was 12 months (range 1-65). This cisplatin/5-FU regimen would appear to produce a low rate of objective response but useful palliative benefits in advanced symptomatic adenoid cystic carcinoma. Prior series suggest that a higher objective response rate may be possible with a platinum/anthracycline/fluorouracil combination, and investigation of such a regimen is warranted.

Adult↗