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Kasonia K, Tindanbil D, Kitonsa J, Baisley K, Zalwango F, Enria L, Mansaray A, James M, Nije Y, Tata DT, Lawal BJ, Drammeh A, Lowe B, Mukadi-Bamuleka D, Mounier-Jack S, Nakiyimba F, Obady P, Muhavi J, Bangura JS, Greenwood B, Samai M, Leigh B, Watson-Jones D, Kavunga-Membo H, Ruzagira E, Gallagher KE. The impact of the COVID-19 pandemic on the provision & utilisation of primary health care services in Goma, Democratic Republic of the Congo, Kambia district, Sierra Leone & Masaka district, Uganda. PLoS One 2023; 18:e0286295. [PMID: 37267240 PMCID: PMC10237403 DOI: 10.1371/journal.pone.0286295] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 05/12/2023] [Indexed: 06/04/2023] Open
Abstract
INTRODUCTION This study aimed to determine whether the COVID-19 pandemic had an impact on essential primary healthcare services at public primary healthcare facilities. METHODS The number of weekly consultations for antenatal care (ANC), outpatient (OPD), immunisations (EPI), family planning (FP) and HIV services, between January 2018 and December 2020, were collected from 25 facilities in Masaka district, Uganda, 21 in Goma, and 29 in Kambia district, Sierra Leone. Negative binomial regression models accounting for clustering and season were used to analyse changes in activity levels between 2018, 2019 and 2020. RESULTS In Goma, we found no change in OPD, EPI or ANC consultations, FP was 17% lower in March-July 2020 compared to 2019, but this recovered by December 2020. New diagnoses of HIV were 34% lower throughout 2020 compared to 2019. In Sierra Leone, compared to the same periods in 2019, facilities had 18-29% fewer OPD consultations throughout 2020, and 27% fewer DTP3 doses in March-July 2020. There was no evidence of differences in other services. In Uganda there were 20-35% fewer under-5 OPD consultations, 21-66% fewer MCV1 doses, and 48-51% fewer new diagnoses of HIV throughout 2020, compared to 2019. There was no difference in the number of HPV doses delivered. CONCLUSIONS The level of disruption varied across the different settings and qualitatively appeared to correlate with the strength of lockdown measures and reported attitudes towards the risk posed by COVID-19. Mitigation strategies such as health communications campaigns and outreach services may be important to limit the impact of lockdowns on primary healthcare services.
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Affiliation(s)
- K. Kasonia
- LSHTM-INRB Research Partnership, Goma, Democratic Republic of the Congo
| | - D. Tindanbil
- LSHTM-COMAHS Research Partnership, Kambia, Sierra Leone
| | - J. Kitonsa
- MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda
| | - K. Baisley
- London School of Hygiene & Tropical Medicine (LSHTM), London, United Kingdom
| | - F. Zalwango
- MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda
| | - L. Enria
- LSHTM-COMAHS Research Partnership, Kambia, Sierra Leone
| | - A. Mansaray
- LSHTM-COMAHS Research Partnership, Kambia, Sierra Leone
| | - M. James
- LSHTM-INRB Research Partnership, Goma, Democratic Republic of the Congo
| | - Y. Nije
- LSHTM-COMAHS Research Partnership, Kambia, Sierra Leone
| | - D. Tetsa Tata
- LSHTM-INRB Research Partnership, Goma, Democratic Republic of the Congo
| | - B. J. Lawal
- LSHTM-COMAHS Research Partnership, Kambia, Sierra Leone
| | - A. Drammeh
- LSHTM-COMAHS Research Partnership, Kambia, Sierra Leone
| | - B. Lowe
- London School of Hygiene & Tropical Medicine (LSHTM), London, United Kingdom
| | - D. Mukadi-Bamuleka
- Laboratoire Rodolphe-Merieux, Institut National de Recherche Biomédicale (INRB-Goma), Goma, Democratic Republic of the Congo
| | - S. Mounier-Jack
- London School of Hygiene & Tropical Medicine (LSHTM), London, United Kingdom
| | - F. Nakiyimba
- Ministry of Health, Masaka, Masaka District, Uganda
| | - P. Obady
- Ministry of Health, Goma, Democratic Republic of Congo
| | - J. Muhavi
- Ministry of Health, Goma, Democratic Republic of Congo
| | - J. S. Bangura
- University of Sierra Leone College of Medicine and Allied Health Sciences (COMAHS), Freetown, Sierra Leone
- Ministry of Health, Kambia, Kambia District, Sierra Leone
| | - B. Greenwood
- London School of Hygiene & Tropical Medicine (LSHTM), London, United Kingdom
| | - M. Samai
- University of Sierra Leone College of Medicine and Allied Health Sciences (COMAHS), Freetown, Sierra Leone
| | - B. Leigh
- University of Sierra Leone College of Medicine and Allied Health Sciences (COMAHS), Freetown, Sierra Leone
| | - D. Watson-Jones
- London School of Hygiene & Tropical Medicine (LSHTM), London, United Kingdom
- Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
| | - H. Kavunga-Membo
- Laboratoire Rodolphe-Merieux, Institut National de Recherche Biomédicale (INRB-Goma), Goma, Democratic Republic of the Congo
| | - E. Ruzagira
- MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda
| | - K. E. Gallagher
- London School of Hygiene & Tropical Medicine (LSHTM), London, United Kingdom
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
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Smout E, Enria L, Mooney T, Lees S, Watson-Jones D, Greenwood B, Leigh B, Larson H. Implementing a novel community engagement system during a clinical trial of a candidate Ebola vaccine within an outbreak setting. Int J Infect Dis 2016. [DOI: 10.1016/j.ijid.2016.02.444] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Zhang Y, Hong H, Yang Y, Severin G, Engle J, Niu G, Chen X, Leigh B, Barnhart T, Cai W. WE-C-217BCD-04: Multimodality Imaging of Breast Cancer Experimental Lung Metastasis. Med Phys 2012; 39:3950. [PMID: 28519986 DOI: 10.1118/1.4736120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Metastatic breast cancer (MBC) is incurable. The clinical gold standard for assessing tumor microvessel density (MVD), an independent prognostic marker in MBC, is CD 105 staining. The goal of this study is to develop a positron emission tomography (PET)/near-infrared fluorescent (NIRF) probe for imaging of CD105 expression in MBC (i.e. non-invasive measurement of MVD), as well as other applications such as early detection of metastasis, intraoperative guidance, etc. METHODS TRC105, a chimeric anti-CD105 mAb, was dual-labeled with a NIRF dye and 89 Zr to yield 8 9 Zr-Df-TRC105-800CW. Luciferase-transfected 4T1 murine breast cancer cells were injected intravenously into female BALB/c mice to establish a lung MBC model. Bio luminescence imaging (BLI) was carried out to non- invasively monitor the lung tumor burden. Comprehensive in vivo/ex vivo studies were performed to investigate 8 9 Zr-Df-TRC105-800CW in this MBC model. Cetuximab was used as an isotype-matched control. RESULTS Radiolabeled TRC105 has high tumor uptake in many tumor types in addition to MBC (e.g. pancreatic/prostate cancer and brain tumor), revealing broad clinical potential for TRC105-based agents. FACS analysis of HUVECs showed no difference in CD 105 binding between TRC105 and Df- TRC105-800CW. PET imaging revealed that 4T1 lung tumor uptake of 89 Zr-Df-TRC105-800CW was 8.7±1.4,10.9±0.5, and 9.7±1.1 %ID/g at 4, 24, and 48 h post-injection (n = 4), with excellent tumor contrast. Bio distribution studies, blocking, control studies with 8 9 Zr-Df-cetuximab- 800CW, ex vivo BLI/PET/NIRF imaging, and histology all confirmed CD 105 specificity of the tracer. NIRF imaging-guided removal of 4T1 tumors with Df-TRC105-800CW in a subcutaneous model was also straightforward. CONCLUSIONS We report the first PET/NIRF imaging of CD105 expression in a MBC model. Broad clinical potential of TRC105- based agents was shown in many tumor types, which also enabled early detection of small metastases and provided intraoperative guidance for tumor removal.
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Affiliation(s)
- Y Zhang
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - H Hong
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - Y Yang
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - G Severin
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - J Engle
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - G Niu
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - X Chen
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - B Leigh
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - T Barnhart
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
| | - W Cai
- University of Wisconsin - Madison, Madison, WI.,NIBIB, Bethesda, MD.,TRACON Pharmaceuticals, Inc., San Diego, CA
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Leigh B, Desneves K, Rafferty J, Pearce L, King S, Woodward M, Brown D, Martin R, Crowe T. The effect of different doses of an arginine-containing supplement on the healing of pressure ulcers. J Wound Care 2012; 21:150-6. [DOI: 10.12968/jowc.2012.21.3.150] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- B. Leigh
- School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | | | | | - L. Pearce
- Austin Health, Heidelberg, Australia
| | - S. King
- Austin Health, Heidelberg, Australia
| | | | - D. Brown
- Austin Health, Heidelberg, Australia
| | - R. Martin
- Austin Health, Heidelberg, Australia
| | - T.C. Crowe
- School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
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Kongnyuy EJ, Leigh B, van den Broek N. Effect of audit and feedback on the availability, utilisation and quality of emergency obstetric care in three districts in Malawi. Women Birth 2008; 21:149-55. [PMID: 18842471 DOI: 10.1016/j.wombi.2008.08.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 08/22/2008] [Accepted: 08/26/2008] [Indexed: 11/25/2022]
Abstract
BACKGROUND Facility-based maternal death reviews and criterion-based clinical audit, were introduced in three districts in Malawi in 2006. RESEARCH QUESTION Can audit and feedback improve the availability, utilisation and quality of emergency obstetric care (EmOC)? PARTICIPANTS AND METHODS Observational study in which emergency obstetric care offered to women who gave birth in 73 health facilities (13 hospitals and 60 health centres) in three districts in Malawi in 2005 (baseline, 41,637 women) was compared to 2006 (43,729 women) and 2007 (51,085 women). RESULTS The number of comprehensive and basic EmOC facilities did not change over the 3-year period (p for trend=1.000). Although institutional delivery rate decreased in 2006, overall it increased over 3 years (p for trend<0.001) - 31.8% (2005), 31.1% (2006) and 34.7% (2007), and Caesarean section rate was low and did not change (p for trend=0.257) - 1.7% (2005), 1.6% (2006) and 1.5% (2007). There was a significant increase in the met need for EmOC (p for trend<0.001) - 15.2% for 2005, 17.0% for 2006 and 18.8% for 2007. Maternal mortality decreased significantly from 250 per 100,000 women in 2005 to 222 in 2006 and 182 in 2007 (p for trend<0.001). Similarly, the case fatality rate decreased monotonically (p for trend<0.001) - 3.7% (2005), 3.0% (2006) and 1.5% (2007). DISCUSSION Audit and feedback can improve availability, utilisation and quality of emergency obstetric care in countries with limited resources. CONCLUSION There is need to increase availability of emergency obstetric care by upgrading some health centres to EmOC level through training of staff and provision of equipment and supplies.
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Affiliation(s)
- E J Kongnyuy
- Child and Reproductive Health Group, Liverpool School of Tropical Medicine, UK.
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Affiliation(s)
- B Leigh
- Hempsons, Hempsons House, 40 Villiers Street, London WC2N 6NJ, UK.
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Barak A, Hauser D, Yipp P, Morse L, Leigh B, Kubo D, Goldberg Z, Earle J, Handa JT. A phase I trial of stereotactic external beam radiation for subfoveal choroidal neovascular membranes in age-related macular degeneration. Br J Radiol 2005; 78:827-31. [PMID: 16110105 DOI: 10.1259/bjr/17631422] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Effective treatment for neovascular age-related macular degeneration (AMD) is currently limited. Radiation therapy, a therapeutic approach with known antiangiogenic properties, has been investigated as a modality to prevent severe visual loss in AMD. Most of the studies using external beam radiation employed <25 Gy to the whole eye, which is below the dose of radiation that is toxic to the retina and optic nerve ( approximately 50 Gy and approximately 59 Gy, respectively). Stereotactic fractionated external beam radiation (St-EBR) is a method that allows radiation to be delivered to a small, defined area. We investigated the effects of St-EBR in incremental doses up to 40 Gy on neovascular AMD. Patients with clinical signs and fluorescein angiography demonstrating neovascular AMD, visual acuity (VA) better than 20/400 and ineligible for laser treatment (MPS criteria) or who refused to have laser photocoagulation were enrolled in the study. Each patient was treated with radiation at incremental dosages from 20 Gy to 40 Gy. After completion of the radiation course, all patients were followed-up at 3 and 7 weeks and 3, 6, and 12 months. Best-corrected VA (ETDRS), slit-lamp and fluorescein angiographic evaluations were performed at each visit. 94 eyes of 89 patients were treated from October 1997 to April 2000. The VA was 0.82+/-0.35 before treatment, 0.83+/-0.36 at 6 months, and 0.89+/-0.33 at 12 months. No patients suffered any significant acute side effects. No significant benefits in either VA or in membrane size were derived from increasing the doses of radiation. Our results are consistent with trends of a palliative benefit of radiotherapy in neovascular AMD and support further investigation of radiotherapy. Since there is no evidence that therapeutic effectiveness is dose dependent, our data provide no justification for potentially dangerous escalations in radiation dosage for treating neovascular AMD.
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Affiliation(s)
- A Barak
- Department of Ophthalmology, UC Davis, Sacramento, CA, USA
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8
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Abstract
OBJECTIVES To determine the mean difference and correlation between capillary and venous bedside glucose estimation in comparison to laboratory blood glucose analysis in emergency department (ED) patients. METHODS Blood glucose levels were synchronously analysed using a bedside blood glucometer on capillary and venous derived samples from consenting ED patients aged >12 years. The venous sample was sent for comparative testing using a laboratory based multichannel analyser. Mean difference and correlation coefficients were determined. RESULTS A total of 20 subjects (aged 13-88 years) were enrolled, with 100% data capture. The mean laboratory glucose was 7.075 mmol/l. The mean capillary blood glucose was 7.66 mmol/l (mean difference compared with mean laboratory glucose 0.58 mmol/l; 95% confidence interval 0.3 to 0.9). The mean venous derived blood glucometer glucose was 7.99 mmol/l (mean difference compared with mean laboratory glucose 0.91 mmol/l; 95% CI 0.6 to 1.2). The correlation coefficient for the laboratory blood glucose versus the capillary blood glucometer glucose was 0.97 mmol/l (p<0.001). The correlation coefficient for the laboratory blood glucose and the venous blood glucometer glucose was 0.96 (p<0.001). Variation occurred between the glucometer and the laboratory blood glucose results. CONCLUSIONS There is a small but significant difference in the blood glucose results analysed on a bedside glucometer when the samples are taken from capillary or venous sources. Although good correlation is the norm between venous and capillary derived samples, caution must be exercised in accepting the results as equivalent or using either as substitutes for a laboratory blood glucose result.
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Affiliation(s)
- R Boyd
- Emergency Department, Lyell McEwin Hospital, Haydown Road, Elizabethvale 5112, South Australia.
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Abstract
PURPOSE To define the in vitro radiosensitivity of Kaposi's sarcoma (KS) and to explore the mechanism of its extreme clinical radiosensitivity. METHODS AND MATERIALS The radiation survivals of the three KS cell cultures (KSY-1, KS-JD, KS6-3E) were determined by clonogenic assay and MTT assay. Supernatants from irradiated cells were collected at different time points for measurement of the interleukin 6 (IL-6), oncostatin M (OSM), and basic fibroblast growth factor (bFGF) by ELISA. Changes in the mRNA expression of these cytokines were examined by reverse transcription polymerase chain reaction and Southern blot hybridization. Fresh KS cells were preincubated with the irradiated supernatant before irradiation, and the change in survivals were assessed. RESULTS The mean SF-2 (survival fraction after 2 Gy) for KS was 0.43. Preincubation with the irradiated supernatant reduced the SF-2 significantly from 0.43 to 0.33 (p < 0.05). Treatment with irradiated supernatant alone was not cytotoxic to the cells. Radiation induced IL-6 and OSM production by KS cells at the transcription level. A single dose of 2 Gy increased IL-6 and OSM mRNA expression of the KS Y-1 cells. This corresponded to an increase in the IL-6 and OSM levels in the culture medium. There was no significant change in the level of bFGF. Preincubation with recombinant human IL-6 or OSM sensitized KS in a dose dependent manner. CONCLUSION The low SF-2 value for these KS cell lines correlates with the clinical radiosensitivity of KS. The high radiosensitivity may be due to radiation induction of cytokines such as IL-6 and OSM, which are radiosensitizers for KS cells.
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MESH Headings
- Blotting, Southern
- Cell Survival/radiation effects
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/radiation effects
- Fibroblast Growth Factor 2/biosynthesis
- Fibroblast Growth Factor 2/genetics
- Gene Expression/radiation effects
- Humans
- Interleukin-6/biosynthesis
- Interleukin-6/genetics
- Interleukin-6/pharmacology
- Oncostatin M
- Peptides/genetics
- Peptides/metabolism
- Peptides/pharmacology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- RNA, Neoplasm/radiation effects
- Radiation Tolerance/drug effects
- Radiation Tolerance/physiology
- Recombinant Proteins/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Sarcoma, Kaposi/genetics
- Sarcoma, Kaposi/metabolism
- Sarcoma, Kaposi/pathology
- Sarcoma, Kaposi/radiotherapy
- Tumor Cells, Cultured/radiation effects
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Affiliation(s)
- A Hong
- Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
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Lau D, Leigh B, Gandara D, Edelman M, Morgan R, Israel V, Lara P, Wilder R, Ryu J, Doroshow J. Twice-weekly paclitaxel and weekly carboplatin with concurrent thoracic radiation followed by carboplatin/paclitaxel consolidation for stage III non-small-cell lung cancer: a California Cancer Consortium phase II trial. J Clin Oncol 2001; 19:442-7. [PMID: 11208837 DOI: 10.1200/jco.2001.19.2.442] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Recent studies have suggested the superiority of concurrent chemoradiotherapy and the efficacy of paclitaxel/carboplatin in advanced non-small-cell lung cancer (NSCLC). In view of those results, we sought to examine the safety and efficacy of administration of radiosensitizing paclitaxel twice weekly and carboplatin weekly with concurrent thoracic radiation therapy (XRT) followed by consolidation paclitaxel and carboplatin for stage III NSCLC in a multi-institutional phase II trial. PATIENTS AND METHODS Induction chemoradiotherapy consisted of paclitaxel 30 mg/m2 delivered intravenously (IV) for 1 hour twice weekly for 6 weeks, carboplatin at a dose based on an area under the concentration-time curve (AUC) of 1.5 mg/mL x min, given IV once weekly for 6 weeks, and concomitant XRT of 1.8 to 2.0 Gy daily for a total of 61 Gy. Patients who achieved a complete response, partial response, or stable disease received two 21-day cycles of consolidation chemotherapy consisting of paclitaxel 200 mg/m2 IV for 3 hours and carboplatin at a dose based on an AUC of 6 mg/mL x min. RESULTS Thirty-four patients were eligible. Their median age was 62 years (range, 39 to 73 years), 59% were female, 41% were male, 94% had a performance status of 0 or 1, 38% had stage IIIA NSCLC, and 62% had stage IIIB NSCLC. Common grade III and IV toxicities during the induction chemoradiation phase included esophagitis (38%) and neutropenia (12%). The most common adverse reaction during consolidation chemotherapy was grade III neutropenia in five patients (15%). The overall response rate was 71%, which was achieved in the induction phase. The median follow-up was 20 months, the median survival was 17 months, and 2-year actuarial survival rate was 40% (95% confidence interval, 20% to 65%). CONCLUSION This regimen is tolerable and results are promising. We recommend further evaluation of this regimen in a phase III trial.
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Affiliation(s)
- D Lau
- University of California, Davis Cancer Center, and Veterans Affairs Northern California Health Care System, Sacramento 95817, USA.
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Gandara D, Lovato L, Albain K, Leigh B, Lara P, Crowley J, Livingston R. Pathologic stage IIIb non-small cell lung cancer (NSCLC): Prolonged survival with consoloidation Docetaxel following concurrent chemoradiotherapy (SWOG 9504). Lung Cancer 2000. [DOI: 10.1016/s0169-5002(00)80303-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Gandara DR, Edelman M, Lara P, Roberts P, Leigh B. Evolution of combined modality therapy for stage III non-small-cell lung cancer. Oncology (Williston Park) 2000; 14:35-41. [PMID: 10981289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
A number of randomized clinical trials and meta-analyses now support the conclusion that combined modality regimens that include cisplatin (Platinol)-based chemotherapy improve survival in stage III non-small-cell lung cancer (NSCLC) more effectively than radiotherapy or surgery alone. Depending on the therapy, chemotherapy may play a cytoreductive role by eradicating distant micrometastases, a radiosensitizing role by improving local control, or do both. In general, sequential therapies in which platinum-based chemotherapy precedes thoracic radiation or surgery have improved outcome by affecting distant metastases. In contrast, concurrent chemoradiotherapy utilizing low-dose cisplatin improves survival by reducing local recurrence without an effect on distant failure rates. In view of these observations, chemoradiotherapy strategies that integrate both radiosensitizing agents and dose levels of chemotherapy that are effective against micrometastases may prove to be most efficacious. Since distant metastases remain the major site of failure, it is also likely that more effective chemotherapy or other systemic antitumor agents are necessary to increase the current level of response and survival. Fortunately, several new chemotherapeutic agents are highly effective against NSCLC as well as potent radiosensitizers.
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Affiliation(s)
- D R Gandara
- Division of Hematology/Oncology, University of California, Davis, USA
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Affiliation(s)
- D R Gandara
- Davis Cancer Center, University of California, Sacramento, USA.
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Lau D, Ryu J, Gandara D, Morgan R, Doroshow J, Wilder R, Leigh B. Concurrent twice-weekly paclitaxel and thoracic irradiation for stage III non-small cell lung cancer. Semin Radiat Oncol 1999; 9:117-20. [PMID: 10210550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Concurrent twice-weekly paclitaxel and thoracic radiation (XRT) for stage III non-small cell lung cancer were studied in a phase I trial. Radiation was delivered in fractions of 1.8 to 2.0 Gy/d to a total dose of 61 Gy. Paclitaxel, at a starting dose of 25 mg/m2/d, was administered intravenously over 1 hour before daily XRT on Mondays and Thursdays for 6 weeks for a total of 12 doses. The paclitaxel dose was escalated by 5 mg/m2/d for each cohort of patients to determine the maximum tolerated dose. The highest dose of paclitaxel reached was 40 mg/m2, which resulted in dose-limiting toxicities of esophagitis and local skin desquamation. For each dose group, the median total number of paclitaxel doses administered was 12 and the median total XRT dose delivered was 61 Gy. The overall response rate was 80%. The overall median survival was 20 months and the 3-year survival rate was 20%. We conclude that the maximum tolerated dose of paclitaxel is 35 mg/m2 given twice weekly for 6 weeks concurrently with XRT. This study provides the basis for using paclitaxel, given twice weekly at 30 mg/m2, with weekly carboplatin and concurrent XRT for stage III non-small cell lung cancer in an ongoing phase II trial.
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Affiliation(s)
- D Lau
- University of California, Davis Cancer Center, Sacramento, CA 95817, USA
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Seaward SA, Weinberg V, Lewis P, Leigh B, Phillips TL, Roach M. Improved freedom from PSA failure with whole pelvic irradiation for high-risk prostate cancer. Int J Radiat Oncol Biol Phys 1998; 42:1055-62. [PMID: 9869229 DOI: 10.1016/s0360-3016(98)00282-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To determine the impact of whole pelvic irradiation on the risk of PSA failure in prostate cancer patients, at high predicted risk for lymph node involvement, receiving definitive radiotherapy. MATERIALS AND METHODS Between October 1987 and December 1995, 506 patients with clinically localized prostate cancer were treated with definitive radiotherapy at UCSF and affiliated institutions. Treatment consisted of 4-field whole pelvic irradiation followed by a prostate-only boost, or prostate-only treatment (median follow-up was 35 months and 30 months, respectively). PSA failure was defined as: 1. a PSA value > or = 1 ng/ml; or 2. a PSA value that rose > or = 0.5 ng/ml in < or = 1 year posttreatment on two consecutive measurements, with the first rise defined as the time of failure. The calculated risk of lymph node positivity (%rLN+) was defined as 2/3(iPSA) + 10(GS-6), and high risk was defined as %rLN+ > or = 15%. Univariate and multivariate analyses were performed. RESULTS A total of 201 high-risk patients were identified. High-risk patients who received whole pelvic irradiation had significantly improved freedom from PSA failure compared to those who received prostate-only treatment (median PFS = 34.3 months vs. 21.0 months; p = 0.0001). Potential confounding variables, including initial PSA, Gleason score, T stage, radiation dose, year of treatment, use of three-dimensional (3D) conformal techniques, and use of hormone therapy, did not account for the observed difference in time to PSA failure. Multivariate analysis revealed type of radiation treatment to be the most significant independent predictor of outcome. CONCLUSION Whole pelvic radiotherapy significantly improves the PSA failure-free survival in patients with a high calculated risk of lymph node positivity.
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Affiliation(s)
- S A Seaward
- Department of Radiation Oncology, University of California, San Francisco Medical Center, USA
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Seaward SA, Weinberg V, Lewis P, Leigh B, Phillips TL, Roach M. Identification of a high-risk clinically localized prostate cancer subgroup receiving maximum benefit from whole-pelvic irradiation. Cancer J Sci Am 1998; 4:370-7. [PMID: 9853136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
PURPOSE We recently identified a progression-free survival advantage for clinically localized high-risk prostate cancer patients receiving whole-pelvic irradiation. We now seek to identify a subgroup most likely to benefit from whole-pelvic irradiation. METHODS Between October 1987 and December 1995, 506 clinically localized prostate cancer patients were treated with definitive radiotherapy consisting of whole-pelvic irradiation followed by a prostate-only boost, or prostate-only treatment (median follow-up, 35 months vs 30 months). Prostate-specific antigen (PSA) failure was defined as (1) a PSA value > or = 1 ng/mL or (2) a PSA value that rose > or = 0.5 ng/mL in < or = 1 year posttreatment on two consecutive measurements, with the first rise defined as the time of failure. The calculated risk of lymph node positivity (%rLN+) was defined as 2/3 (initial PSA) + 10(Gleason score - 6), with intermediate risk defined as 15% < or = %rLN+ < 35% and highest risk defined as %rLN+ > or = 35%. Univariate and multivariate analyses were performed. RESULTS Intermediate-risk patients receiving whole-pelvic irradiation had significantly improved freedom from PSA failure compared with those receiving prostatic irradiation only (median progression-free survival 39.5 months vs 22.5 months; P < 0.0001); highest-risk patients did not (median progression-free survival 27.2 months vs 20.8 months, P = NS). Multivariate analysis revealed type of radiation treatment to be the most significant independent predictor of outcome (P < 0.0001). DISCUSSIONS Whole-pelvic radiotherapy most significantly improves the PSA failure-free survival in patients with an intermediate calculated risk of lymph node positivity, suggesting that highest-risk patients may present with distant micrometastases.
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Affiliation(s)
- S A Seaward
- Department of Radiation Oncology, University of California, San Francisco Medical Center 94143, USA
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Lau DH, Crowley JJ, Gandara DR, Hazuka MB, Albain KS, Leigh B, Fletcher WS, Lanier KS, Keiser WL, Livingston RB. Southwest Oncology Group phase II trial of concurrent carboplatin, etoposide, and radiation for poor-risk stage III non-small-cell lung cancer. J Clin Oncol 1998; 16:3078-81. [PMID: 9738578 DOI: 10.1200/jco.1998.16.9.3078] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE A phase II study was conducted by the Southwest Oncology Group (SWOG) to assess the efficacy and toxicity of concurrent carboplatin, etoposide, and thoracic radiation (XRT) in a defined population of poor-risk patients with stage III non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Patients with stage III NSCLC were eligible if they were excluded from cisplatin-based protocols because of poor pulmonary or renal function, history of congestive heart failure, hearing loss, peripheral neuropathy, or weight loss. Carboplatin 200 mg/m2 daily intravenously days 1, 3, 29, and 31 and etoposide 50 mg/m2 daily intravenously days 1 through 4 and 29 through 32 were administered. Beginning day 1, XRT was delivered at 1.8 to 2.0 Gy daily to a total dose of 61 Gy. RESULTS Within a period of 1 year, 63 patients were registered and 60 were eligible. Patient characteristics were age 47 to 79 years, performance status 0 to 1 (82%) and 2 (18%), and stages IIIA (60%) and IIIB (40%) NSCLC. The most common grades 3 and 4 toxicities included leukopenia (50%), thrombocytopenia (23%), and esophagitis (15%). There were no treatment-related deaths. The overall confirmed response rate was 29%, and median overall survival was 13 months (95% confidence interval, 11 to 14 months). The 2-year survival rate was 21%. CONCLUSION This chemoradiotherapy regimen is well tolerated in poor-risk patients and yields a median survival similar to that of good-risk patients who received cisplatin-based chemoradiotherapy. This chemoradiotherapy regimen will be compared with XRT alone in poor-risk patients with stage III NSCLC in a randomized phase III trial.
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Affiliation(s)
- D H Lau
- University of California Davis Cancer Center, Sacramento, USA
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Leigh B, Kandeh HB, Kanu MS, Kuteh M, Palmer IS, Daoh KS, Moseray F. Improving emergency obstetric care at a district hospital, Makeni, Sierra Leone. The Freetown/Makeni PMM Team. Int J Gynaecol Obstet 1997; 59 Suppl 2:S55-65. [PMID: 9389614 DOI: 10.1016/s0020-7292(97)00148-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PRELIMINARY STUDIES A facility review and focus group discussions revealed poor capacity to manage obstetric complications. INTERVENTIONS In response, a physician with obstetric skills was posted, and a second physician was trained. Courses in life-saving obstetric skills were held for nurses and midwives. An unused operating theater was made functional with simple modifications. A generator and blood bank were installed. Drugs and supplies were made available through a revolving fund. Subsequently, community interventions focused on improving utilization. RESULTS The number of women seeking treatment for major obstetric complications at the district hospital increased from 31 in 1990 to 98 in 1995, while the case fatality rate (CFR) among these women dropped from 32% to 5%. Cesarean sections increased from two in 1990 to 38 in 1995. In 1995, 444 abortion-related procedures were performed--almost all of them for unwanted pregnancy--compared with only 22 in 1990. COSTS The cost of material improvements and training was approximately US$39,000, of which 46% was from project funds, 41% from non-governmental organizations and 13% from government. CONCLUSIONS Women with obstetric complications will seek hospital care if services are available. Government hospital services can be improved by building on existing resources. Obstetric CFR can be dramatically reduced. The need for safe abortion services, which are currently illegal in Sierra Leone, is demonstrated.
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Affiliation(s)
- B Leigh
- Ministry of Gender and Children's Affairs, Government Hospital-Makeni, Sierra Leone
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Kandeh HB, Leigh B, Kanu MS, Kuteh M, Bangura J, Seisay AL. Community motivators promote use of emergency obstetric services in rural Sierra Leone. The Freetown/Makeni PMM Team. Int J Gynaecol Obstet 1997; 59 Suppl 2:S209-18. [PMID: 9389633 DOI: 10.1016/s0020-7292(97)00167-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PRELIMINARY STUDIES An appraisal of government health facilities documented generally poor conditions, a shortage of drugs and supplies, and inadequate skills among staff. Focus group discussions in the community revealed a lack of knowledge about obstetric complications and difficulty in reaching health facilities. INTERVENTIONS Improvements were made in services at primary health units (PHUs) through May 1993. Community motivators were trained in June and provided with bicycles and raingear in September 1993. Among their duties were community education, formation of village action groups for emergency transport and facilitation of referral for women with obstetric complications. RESULTS Between August 1992 and December 1995, women with major complications seen at the PHUs increased from nine to 16 per month, with fluctuations due to disruptions in services and civil strife. The proportion of women with complications who were referred by the community motivators diminished over time, dropping from 24% to 1% over the first two years (1993-1994) and then recovering somewhat to 10% in the final period of observation. COSTS The cost of this intervention was approximately US$5082, with about half coming from the project and the rest from the government (44%) and the community (8%). CONCLUSIONS The project improved utilization of the PHUs by women with complications, indicating that once services are of acceptable quality, many women will use them. The contribution of the motivators was positive, though smaller than expected.
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Affiliation(s)
- H B Kandeh
- Interim National Electoral Commission, Freetown, Sierra Leone
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Lau D, Gandara D, Ryu J, Morgan R, Doroshow J, Wilder R, Leigh B. 282 Phase I trial of concurrent irradiation and bi-weekly paclitaxel for stage III non-small-cell lung cancer. Lung Cancer 1997. [DOI: 10.1016/s0169-5002(97)89666-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Lau DH, Ryu JK, Gandara DR, Morgan R, Doroshow J, Wilder R, Leigh B. Twice-weekly paclitaxel and radiation for stage III non-small cell lung cancer. Semin Oncol 1997; 24:S12-106-S12-109. [PMID: 9331132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A phase I study was conducted to investigate the safety and efficacy of twice-weekly paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and concurrent thoracic irradiation in patients with stage III non-small cell lung cancer. Radiation therapy beginning on day 1 was delivered in 1.8- to 2.0-Gy daily fractions, to a total dose of 61 Gy. Paclitaxel at a starting dose of 25 mg/m2/d was administered intravenously over 1 hour before daily radiation on days 1, 4, 8, 11, 15, 18, 22, 25, 29, 32, 36, and 39, for a total of 12 doses over 6 weeks. The paclitaxel dose was escalated by 5 mg/m2/d in each cohort of patients to determine the maximum tolerated dose. The highest paclitaxel dose reached was 40 mg/m2/d, as defined by dose-limiting toxicities of esophagitis and desquamation within the radiation fields. For each dose group, the median total number of paclitaxel doses administered was 12 and the median total radiation dose was 61 Gy. Response rates ranging from 50% to 100% were observed (three of six patients at paclitaxel 25 mg/m2, four of six at 30 mg/m2, seven of seven at 35 mg/m2, six of six at 40 mg/m2), for an overall response rate of 80%. We conclude that the maximum tolerated dose of paclitaxel is 35 mg/m2 given twice weekly in a 1-hour infusion for 6 weeks concurrently with thoracic irradiation. This study provides the basis for an ongoing trial combining twice-weekly paclitaxel and carboplatin with concurrent thoracic irradiation for patients with stage III non-small cell lung cancer.
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Affiliation(s)
- D H Lau
- University of California, Davis Cancer Center, Sacramento 95817, USA
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Abstract
The causal link between therapeutic irradiation and malignant melanoma has not been firmly established. The authors report a novel case of a malignant melanoma arising from a therapeutically irradiated neovagina reconstructed from skin flaps following radical vulvectomy with inguinal lymph node dissection 16 years earlier. The diagnosis was established by light microscopy and immunohistochemical staining. Reports of melanoma arising from sites of previous radiation therapy are reviewed. Our observations suggest that therapeutic radiation may be a factor in the development of malignant melanoma, particularly in non-sun-exposed areas, including the genital tract.
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Affiliation(s)
- P N Lara
- Division of Hematology-Oncology, University of California Davis Cancer Center, Sacramento 95817, USA
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Wright DO, Leigh B. The impact of the Expanded Programme on Immunisation on measles-induced sensorineural hearing loss in the western area of Sierra Leone. West Afr J Med 1995; 14:205-9. [PMID: 8634225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Measles was found to be responsible for 46.1% of acquired sensorineural hearing loss in children in a study conducted in the western area of Sierra Leone between 1975 to 1985. 125 children with acquired sensorineural hearing loss were seen and investigated in this study, which was conducted to determine the impact of the Expanded Programme on Immunisation and measles-induced hearing loss. 17 children had sensorineural hearing loss consequent to an attack of measles. A progressive drop in the number of cases seen from 6 in 1986 to 0 in 1989 was observed. During the same period the measles immunisation coverage in Sierra Leone increased from 21% in 1986 to 75% in 1990. Given that measles and some other causes of sensorineural hearing loss were preventable, it was hypothesised that lower incidence of these diseases would result in lower rates of acquired sensorineural hearing loss. This study demonstrated an inverse relationship between the incidence of measles induced sensorineural hearing loss and the increased immunisation coverage when Universal Child Immunisation (UCI) was attained in 1990.
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Affiliation(s)
- D O Wright
- Department of Otolaryngology, Connaught Hospital, Freetown, Sierra Leone
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Leigh B. Case management in a health maintenance organization: improving quality of care. AAOHN J 1993; 41:170-173. [PMID: 8507282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
1. Given the current climate in the health care industry, the occupational health nurse can take the opportunity to formalize the case management role. 2. A unique aspect of case management within the structure of a health maintenance organization allows for effective use of existing internal services and occupational health staff. 3. In developing an occupational case management model, a framework was constructed to include the core aspects of management for all injured workers. A four level system was developed to meet the injured workers' need for the coordination of care and, when indicated, intensive case management. 4. Improved quality of care for the injured worker and a return to an optimal state of health and productivity is already being realized. Formalized evaluation will provide objective measurements of program efficacy and future planning.
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Abstract
We retrospectively reviewed six patients with squamous cell carcinoma of the anus (SCCA) and human immunodeficiency virus (HIV) infection treated between 1985 and 1988. All six patients were homosexual men. Five patients had AIDS and one was HIV-positive. The most common symptoms and signs were pain (n = 5), mass (n = 5), and bleeding (n = 5). The average tumor size was 3.2 cm with a range of 1-10 cm. Five tumors were located in the anal canal and one at the anodermal junction. One patient was treated with biopsy alone, one with local excision, one with wide local excision and radiation therapy, and two with diverting colostomy. The average follow-up was 8 months. Of the five AIDS patients, two died, one was transferred to a hospice facility, one was lost to follow-up, and one remains alive 1 year following treatment. The HIV-positive patient died secondary to metastatic SCCA. This group of patients raises the question of a possible association between HIV and SCCA.
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Affiliation(s)
- H P Lorenz
- Department of Surgery, University of California, San Francisco 94110
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Abstract
We retrospectively reviewed eight patients with biopsy-proven anorectal Kaposi's sarcoma (KS) treated between 1984 and 1989 at San Francisco General Hospital. All patients were homosexual men with the acquired immunodeficiency syndrome (AIDS). The average age was 34 years. Three patients had primary rectal KS without metastases. Five patients had disseminated KS with lesions throughout the alimentary tract, viscera, skin, or local lymph nodes. Three patients were treated with radiation or chemotherapy. Five patients had disseminated KS with lesions throughout the alimentary tract, viscera, skin, or local lymph nodes. Three patients were treated with radiation or chemotherapy. Five patients with advanced AIDS received no specific treatment for anorectal KS. Follow-up ranged from 1 month to 5 years. Three of the untreated patients and the three patients treated with chemotherapy or radiotherapy were alive 1 month to 5 years after diagnosis. Aggressive surgical treatment of anorectal KS is not indicated.
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Affiliation(s)
- H P Lorenz
- Department of Surgery, University of California, San Francisco General Hospital 94110
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Leigh B, Guisinger D, Fech J. Blood pressure screening in the workplace. AAOHN J 1989; 37:14-7. [PMID: 2909216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Leigh B, Schalet AP, Paradi E. Neutron- and X-ray-induced mutations at the yellow, white, forked and vermilion loci of Drosophila melanogaster; a preliminary analysis. Mutat Res 1982; 92:133-8. [PMID: 6806649 DOI: 10.1016/0027-5107(82)90217-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Neutrons and X-rays were used to induce mutations at the yellow, white, vermilion and forked loci of Drosophila melanogaster by irradiation of spermatozoa in males. The mutations were characterized for the presence and location of simultaneously induced rearrangements and recessive lethal mutations. F1 females carrying induced visible mutations were identified, described and tested for fertility. The data are given in this paper. The proportions of mutants at the 4 loci, the ratios of whole-body: mosaic mutations, and the fertility of the mutant-carrying F1 females were similar for both types of radiation. Differences were observed between the frequencies of induced visible mutations and the rates of coincident visible and lethal induction. Although the analysis of the mutant chromosomes has not yet been completed, our data can be interpreted as providing confirmation that there are qualitative differences between the genetic effects of neutrons and X-rays.
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Breckenridge RJ, Nicholson SH, Nicol AJ, Suckling CJ, Leigh B, Iversen L. Inhibition of neuronal GABA uptake and glial beta-alanine uptake by synthetic GABA analogues. Biochem Pharmacol 1981; 30:3045-9. [PMID: 7337721 DOI: 10.1016/0006-2952(81)90491-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Leigh B, Veerkamp-van Baarle AM, Sobels FH, Broerse JJ. Neutrons and X-rays, comparative studies with Drosophila melanogaster. 2. Sex-chromosome loss and partial loss, evidence for the induction of chromatid aberrations in spermatozoa. Mutat Res 1981; 84:107-12. [PMID: 6799814 DOI: 10.1016/0027-5107(81)90054-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Losses and duplications of BSY y+-chromosome markers were induced by irradiation of spermatozoa with either 0.5-MeV neutrons or 100-kV X-rays. These 2 types of radiation are known to induce significantly different ratios of double:single strand breaks in DNA. Exceptional progeny were grouped into 3 categories; no Y marker, one Y marker, and Y marker duplications + mosaics. The last combination consisted of exceptions derived from only chromatid-type rearrangements. All other classes of exceptions may be derived from either chromatid- or chromosome-type rearrangements. Doses of 15 Gy neutrons and 27 Gy X-rays induced identical frequencies of exceptional progeny, giving an RBE of 1.8. The ratios of the 3 classes of exceptions were similar for both types of radiation. This observation can be interpreted as indicating that, under the conditions used here, chromosome and chromatid rearrangements are not derived directly from double and single DNA strand breaks, respectively.
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Leigh B, van Steenbrugge GJ, Robinson AS. Neutrons and X-rays, comparative studies with Drosophila melanogaster. 1. The viability and fertility of induced autosomal translocations. Mutat Res 1981; 84:101-5. [PMID: 6799813 DOI: 10.1016/0027-5107(81)90053-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Studies on the genetic effects of neutrons and X-rays have produced evidence that may be interpreted as indicating that neutrons induce clusters of closely linked genetic changes. According to this interpretation, it is to be expected that neutron-induced translocations will have a higher rate of associated recessive lethality, compared with translocations induced by low-LET radiation such as X-rays. The experiment reported here was designed to test whether this expectation is fulfilled. The dose--frequency response with neutrons for the induction of autosomal translocation was established by exposing males from the Oregon-K stock and then sampling treated mature sperm. From the data obtained, it was estimated that 10 Gy neutrons should induce about the same frequency of autosomal translocations as 27 Gy X-rays. These 2 doses were used to induce translocations in the spermatozoa of males carrying lethal-free autosomes, derived from the Oregon-K stock. Induced translocations were tested for homozygous viability and fertility. When these criteria were used, no qualitative difference was detected between the translocations induced by neutrons and X-rays.
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Breckenridge RJ, Nicholson SH, Nicol AJ, Suckling CJ, Leigh B, Iversen L. Inhibition of [3H]GABA binding to postsynaptic receptors in human cerebellar synaptic membranes by carboxyl and amino derivatives of GABA. J Neurochem 1981; 37:837-44. [PMID: 6275034 DOI: 10.1111/j.1471-4159.1981.tb04469.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Fifty synthetic analogues of GABA were tested for their ability ot interact with GABA receptors, using [3H]GABA binding to human cerebellar membranes as an in vitro model. The most active compounds were found to be aliphatic and heterocyclic aminosulphonic acids. Compounds with highly substituted nitrogen atoms were only weakly active unless a long alkyl chain, which can interact with the postsynaptic membrane, was present. It was concluded that a pyramidal nitrogen atom is favoured fro binding of GABA analogues to human cerebellar membranes.
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Leigh B. Ingrowing toenail. Aust Fam Physician 1981; 10:720. [PMID: 7305751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Aaron CS, Leigh B. X-ray induced sex-chromosome loss, when ring-X chromosome males are irradiated and mated to females carrying mei-9, mei-41 or mei-218. Mutat Res 1981; 82:381-8. [PMID: 6790981 DOI: 10.1016/0027-5107(81)90167-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Radiation damage induced in the sperm nucleus is repaired after this nucleus has entered the oocyte. The yield of induced genetic damage is known to be dependent on maternal genotype and can also be modified by treatment of the females with metabolic inhibitors. The experiments reported here were designed to find out whether a more specific analysis of the interaction between male gamete and oocyte cytoplasm can be carried out using mutants that are known to affect repair processes. Males carrying ring-X chromosomes were exposed to X-ray doses up to 1000 R and mated to females homozygous for a repair-deficient mutant. The mutants used were mei-9a, mei-9L1, mei-41A10, and mei-41D5. In addition a yellow (y) X chromosome was used as a control and an attempt was made to obtain data using mei-21815, a mutant at a locus not thought to affect repair. With mei-9 mutants there is an enhancement of the spontaneous and induced rates of paternal sex-chromosome loss. The mei-41 mutants did not affect the rates of paternal sex-chromosome loss. Mei-218 females were difficult to work with because they gave very few progeny. From these data it can be argued that repair-deficient mutants will indeed be useful for an analysis of the fixation of radiation-induced genetic damage.
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Abstract
Wild-type ORK Drosophila melanogaster males were given an exposure of 3000 R X-radiation. Mature sperm were then sampled by mating to X.Y/X.Y, X.Y/X, or X/X females that carried markers on the second and third chromosomes for the detection of induced autosomal translocations. Two pairs of maternal stocks were used and heterozygous X.Y/X females were obtained by making both reciprocal crosses. The highest frequencies of induced translocations were obtained with X/X females. In one series these frequencies are higher than those obtained with either X.Y/X or X.Y/X.Y females. In the other series a uniform frequency of translocations was obtained with all types of female, except for one of the two types of heterozygous female, which gave lower frequencies. The experiments have provided data which show that the addition of Y-chromosomes to the maternal genome does not have a specific effect on the recovery of induced paternal autosomal translocations. Maternal Y-chromosomes increased the proportions of fertile F1 males, this effect being consistent in direction but varying in degree.
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Abstract
Nondisjunction of the sex chromosomes and compound-second chromosomes was induced in Drosophila melanogaster by irradiation of immature oocytes and cold treatment of mature oocytes. These two treatments cause nondisjunction by different mechanisms. This results in a differential for stage sensitivity and the production of relatively different frequencies of the various exceptional progeny classes.
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Abstract
Chromosomes and chromatid-type rearrangements can be induced by exposure of spermatozoa of Drosophila to ionising radiation. A model, proposed to explain the formation and recovery of compound autosomes, has been extended to account for the induction of centric fragments capped by a duplication of paternal chromosome material. Three basic assumptions have been used; (1) that the sperm nucleus contains a haploid set of unreplicated chromosomes, (2) that the broken chromosome ends can be joined together before or after replication, and (3) that one of the first two cleavage nuclei may be lost and an adult organism derived from the other. The present paper reports a theoretical application of this combination of assumptions to the general case of the formation and recovery of two-break rearrangements. This has led to an elucidation of the relation between repeats, compounds, fragments, and deficiencies on the one hand and inversions and translocations on the other hand. Dicentric chromosomes and segmental aneuploidy can be simply explained. A selective screen is formed by the segregation of chromatid rearrangements and the aneuploidy tolerance levels of the early cleavage nuclei. Thus there is an alternative way of explaining observations which might indicate preferential breakage or joining.
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Abstract
Drosophila melanogaster males with marked X and Y chromosomes were irradiated, and mature sperm sampled by mating the males to females carrying attached-X chromosomes. Induced loss and partial loss of the paternal sex chromosomes was studied. F1 females were scored according to their phenotype, and transmitted fragments were analyzed genetically. Half of the exceptional F1 females could be scored as "partial losses". Of the apparent total loss exceptions, which were tested, half were carrying detectable fragments. 21% of the transmissible fragments is an under-estimate because only 6 of the 10 chromosome tips were marked in such a way that duplications could be detected. In addition, the markers used were located near, but not at, the chromosome ends. These data are interpreted as indicating that a high proportion of the chromosome loss and partial loss, induced by irradiation of mature sperm, is a consequence of chromatid rearrangements arising from chromosome breaks which stay open until replication. It is suggested that, during the transition from sperm head to mature pronucleus, repair of breaks and chromosome replication are two processes that occur in overlapping time intervals. It is therefore possible for chromosome breaks induced in mature sperm to give rise to chromosome and chromatid rearrangements.
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Vogel E, Leigh B. Concentration-effect studies with MMS, TEB, 2, 4, 6-TriCl-PDMT, and DEN on the induction of dominant and recessive lethals, chromosome loss and translocations in Drosophila sterm. Mutat Res 1975; 29:383-96. [PMID: 809703 DOI: 10.1016/0027-5107(75)90059-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Comparative tests were made with four mutagens, treating male germ cells, particularly mature sperm, of Drosophila melanogaster. Dominant lethals, sex-linked recessive lethals, sex-chromosome loss and partial loss, and in one test translocations were used as genetic and points. The four mutagens, methanesulphonate (MMS), 2,3,5,6-tetraethyleneimino-I,4-benzoquinone (TEB), I(2,4,6-trichlorophenyl)-3,3-dimethyltriazene (2,4,6-triC1-PDMT), and diethyl nitrosamine (DEN) are known to differ in their chemical properties and mode of mutagenic action. An apparent relationship between dominant lethal induction and other genetic damage was found only with TEB. All four mutagens are efficient inducers of sex-linked recessive lethals. At low concentrations there was no direct concentration-frequency relationships. The two direct mutagens, MMS and TEB were effective in the chromosome loss tests. DEN does not induce translocations or any of the other types of damage studied which can be attributed to chromosome breakage. It is concluded that the sex-linked recessive lethal test is a simple and efficient way of preliminary screening chemical mutagens with Drosophila melanogaster.
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van Steenis H, Tuscany R, Leigh B. The distribution of x-ray induced chromosomal abnormalities in rat kangaroo (Potorous tridactylis) cells in vitro. Mutat Res 1974; 23:223-8. [PMID: 4134768 DOI: 10.1016/0027-5107(74)90142-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Leigh B. Interaction of chromosome breaks in spermatids and spermatocytes of Drosophila melanogaster. Mutat Res 1971; 12:211-3. [PMID: 4999368 DOI: 10.1016/0027-5107(71)90145-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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48
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Sobels FH, Leigh B. The induction by x-rays of double mosaics involving the Y-chromosome, supporting first cleavage segregation in Drosophila melanogaster. Mutat Res 1971; 12:100-1. [PMID: 4999504 DOI: 10.1016/0027-5107(71)90078-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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49
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Leigh B. Venous ulceration--a further factor. Med J Aust 1970; 2:1030-1. [PMID: 5494952 DOI: 10.5694/j.1326-5377.1970.tb63326.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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