Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21
Filter
1.
Ann R Coll Surg Engl ; 102(8): 594-597, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32538104

ABSTRACT

INTRODUCTION: The National Bowel Cancer Screening Programme guidelines advocate the use of endoscopic tattooing for suspected malignant lesions to assist identification and to facilitate laparoscopic resections. However, endoscopic tattooing practices are variable in endoscopic units, resulting in repeat endoscopy and delay in patient management. The aim of this study was to assess the adherence to tattoo protocol for significant colonic lesions at an endoscopy unit in a large district general hospital. MATERIALS AND METHODS: Prospectively collected data were analysed for 252 patients with significant colonic lesions between January 2017 and December 2018. Data were collected through reviewing patient's notes, histopathology findings and endoscopy reports. Data on lesions, complications, number and site of tattoo placed, and any repeat endoscopy for a tattoo were collected. RESULTS: Of the 252 patients, 88% (n = 222) had malignant and 12% (n = 30) had benign lesions. Only 58.7% (n = 148) of those patients who had colonoscopy had tattoo placement reported. Of these 148 cases, the report stated the distance of tattoo in relation to the lesion in only 46% (n = 68) of patients. Unfortunately, 14.3% (n = 36) of patients required repeat endoscopy to tattoo the lesions prior to surgery. CONCLUSIONS: Our study highlights the lack of uniformity of tattoo practice among endoscopists. Despite the National Bowel Cancer Screening Programme guidelines, a significant proportion of colorectal lesions are still not tattooed during their first endoscopy. Some patients had to have repeat endoscopy just for the purpose of tattooing. Active involvement and participation of all endoscopists in the colorectal and the complex polyp multidisciplinary teams may help to improve the tattoo service.


Subject(s)
Colonoscopy/methods , Colorectal Neoplasms/surgery , Laparoscopy/methods , Tattooing/methods , Aged , Aged, 80 and over , Carbon/therapeutic use , Colon/pathology , Colon/surgery , Colorectal Neoplasms/pathology , Humans , Middle Aged , Reoperation , Retrospective Studies
3.
Rev Sci Instrum ; 87(4): 045104, 2016 04.
Article in English | MEDLINE | ID: mdl-27131704

ABSTRACT

The depth of surface damage (or simply, damage) in crystalline silicon wafers, caused by wire sawing of ingots, is determined by performing a series of minority carrier lifetime (MCLT) measurements. Samples are sequentially etched to remove thin layers from each surface and MCLT is measured after each etch step. The thickness-removed (δt) at which the lifetime reaches a peak value corresponds to the damage depth. This technique also allows the damage to be quantified in terms of effective surface recombination velocity (Seff). To accomplish this, the MCLT data are converted into an Seff vs δt plot, which represents a quantitative distribution of the degree of damage within the surface layer. We describe a wafer preparation procedure to attain reproducible etching and MCLT measurement results. We also describe important characteristics of an etchant used for controllably removing thin layers from the wafer surfaces. Some typical results showing changes in the MCLT vs δt plots for different cutting parameters are given.

4.
Colorectal Dis ; 12(7): 632-9, 2010 Jul.
Article in English | MEDLINE | ID: mdl-19486094

ABSTRACT

OBJECTIVE: To assess the compliance of the surveillance colonoscopy waiting list with ACPGBI/BSG guidelines for colonoscopy follow-up and to measure the impact of adjusting referrals to be inline with the guidelines. DESIGN AND SETTING: This is a quantitative five-stage clinical audit cycle involving a large patient cohort from the Kent and Medway Cancer Network, which includes seven hospitals across four NHS Hospital Trusts and an estimated population of 1.8 million. PARTICIPANTS: 3020 patients were waiting for a surveillance colonoscopy. Their notes were reviewed and the indications for colonoscopy were compared with the ACPGBI/BSG 2002 guidelines. INTERVENTIONS: Those patients whose referral to the surveillance colonoscopy waiting list was not found to be compliant were adjusted to be inline with the guidelines. MAIN OUTCOME MEASURES: The impact of adjusting the surveillance colonoscopy waiting list on the diagnostic colonoscopy service was assessed by measuring the average waiting times for a colonoscopy before and after the intervention. RESULTS: Around 22% (n = 664) of surveillance colonoscopy referrals were inline with the guidelines, 51% (n = 1540) could be cancelled from the list and 27% (n = 816) could be given a new date. Implementing these recommendations reduced the average wait for a diagnostic colonoscopy from 76.8 to 56.0 days (P = 0.0022). CONCLUSION: Following guidelines for surveillance colonoscopy can reduce waiting times for diagnostic colonoscopy. This allows a faster patient journey for diagnostic colonoscopy and a uniform plan for duration and frequency of surveillance colonoscopy. However, this action promoted serious debate on the social, moral and ethical issues.


Subject(s)
Colonoscopy , Colorectal Neoplasms/diagnosis , Guideline Adherence , Guidelines as Topic , Patient Compliance/statistics & numerical data , Waiting Lists , Humans , United Kingdom
6.
Colorectal Dis ; 9(9): 830-3, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17931172

ABSTRACT

OBJECTIVE: To assess the referral practice for surveillance colonoscopy amongst clinicians and to measure whether practice was inline with the current Association of Coloproctology of Great Britain and Ireland (ACPGBI) and the British Society of Gastroenterology (BSG) guidelines. METHOD: A questionnaire was sent to members of the ACPGBI. RESULTS: A total of 195 (49%) clinicians responded, providing information on their referral habits with comments on where they deviated from the guidelines. CONCLUSIONS: The BSG and ACPGBI guidelines are well established amongst clinicians and generally accepted as best practice, however, the majority of clinicians deviate from the guidelines for particular clinical scenarios. In fact only 18% of respondents followed all recommendations for surveillance colonoscopy for patients with polyps, previous cancers and a family history.


Subject(s)
Colonoscopy/methods , Colorectal Neoplasms/prevention & control , Guideline Adherence , Population Surveillance , Practice Guidelines as Topic , Adult , Aged , Aged, 80 and over , Colorectal Neoplasms/surgery , Humans , Middle Aged , Risk Factors , Surveys and Questionnaires
8.
Colorectal Dis ; 8(6): 480-3, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16784466

ABSTRACT

OBJECTIVE: Three thousand five hundred and forty-nine patients are waiting for a colonoscopy in the Kent and Medway cancer network. New guidelines identify those who require surveillance for polyp, cancer, IBD and family history. Our hypothesis was that most of the patients on the waiting list would no longer need a colonoscopy if the new guidelines were applied. PATIENTS AND METHODS: We compared the ACPGBI guidelines for screening/surveillance colonoscopy with the indications in 411 notes of one hospital's waiting list and removed patients as appropriate. In the second part of study we analysed 192 patients attending colonoscopy in seven hospitals in the region and calculated the potential impact of the guidelines on our waiting lists. RESULTS: Of 411 patients on the waiting list in one hospital, only 98 (24%) needed to remain on the list. 142 (34%) were cancelled completely. One hundred and seventy-one (42%) were taken off the 'waiting' list and rebooked for a later date since according to the new guidelines the colonoscopy was not due yet. Of 192 colonoscopies actually performed during the study period in 7 hospitals of Kent and Medway cancer network, 72 (38%) were for surveillance. Two thirds of those were not in line with the guidelines. As a result of implementing the guidelines, waiting times for diagnostic colonoscopy fell from 12 to 4 weeks for urgent, and from 40 to 15 weeks for routine referrals. CONCLUSION: A quarter of the 8000 colonoscopies performed annually in our region are unnecessary when compared to the guidelines. More than three quarters of our waiting list could be removed by reviewing the notes. Implementing the guidelines in one cancer network would save pounds 1 million per year even on conservative estimates of pounds 500 per colonoscopy. It would also reduce the waiting times for diagnostic colonoscopy.


Subject(s)
Colonoscopy/standards , Colorectal Neoplasms/diagnosis , Hospitals, Public/standards , Practice Guidelines as Topic , Waiting Lists , Colonoscopy/statistics & numerical data , Guideline Adherence , Humans , Practice Patterns, Physicians' , Referral and Consultation/statistics & numerical data , Risk Assessment , Time , United Kingdom , Unnecessary Procedures/statistics & numerical data
9.
Colorectal Dis ; 8(2): 135-9, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16412074

ABSTRACT

OBJECTIVES: The majority of colorectal cancers (CRC) are not diagnosed through the Rapid access route (RAR) and follow-ups (FU) may prolong outpatient-waiting time for new referrals. The aim of this study was to assess the relative contributions of an efficient colorectal clinic and a stringent colonoscopy booking system on the total journey time for CRC. PATIENTS AND METHODS: We reduced the number of follow-up appointments with the introduction of 'Paper clinics'. The composition of the new clinic was determined by the known cancer yield through RAR and non-RAR route. A prospective analysis of clinics and CRC journey times was undertaken from November 2003 for 13 months, with the new outpatient clinic template introduced in December 2003. This coincided with a stringent policy on referral pattern for colonoscopy. RESULTS: In our hospital, only 4% of RAR yield CRC. Seventy-five percent of our CRC are referred through the non-RAR route. Eighty-one percent of follow-ups in a 'paper clinic' were discharged. A flexible template for the outpatient clinics, introduced a corresponding reduction in follow-up and increased urgent and routine slots. There was a progressive drop in the follow-up to new ratio and the waiting times for routine and urgent category decreased from a median of 15.9 and 3.4 weeks to 6.7 and 0.7 weeks, respectively (P < 0.001). Average waiting times for all categories fell from 13.35 weeks in November 2003 to 3.5 weeks in December 2004, while the number of patients waiting less than 4 weeks rose from 46% to 71%. This was associated with reduction in total journey times from 93 days to 62 days (P < 0.05). DNA rates remained unaffected. CONCLUSION: Modifying outpatient clinic composition with 'paper clinics' reduces the waiting time for all referrals to a surgical clinic with a modest effect on CRC clinic waiting time. Reduction in the total waiting time to first treatment (for CRC) is due to reducing the demand on colonoscopy in favour of barium enema. Redirecting the flow of patients towards barium enema is perhaps one way of improving the existing CRC journey time to first treatment, within existing resources. Achieving the 62 day target for cancer journey time will be difficult unless traditional surgical clinic habits are challenged.


Subject(s)
Ambulatory Care Facilities/organization & administration , Colonoscopy/statistics & numerical data , Colorectal Neoplasms/diagnosis , Waiting Lists , Ambulatory Care Facilities/statistics & numerical data , Humans , Referral and Consultation , United Kingdom
10.
J Phys Condens Matter ; 18(6): 1977-86, 2006 Feb 15.
Article in English | MEDLINE | ID: mdl-21697570

ABSTRACT

The structural, electronic, optical, and mechanical properties of stoichiometric TaC(x)N(y = 1-x) were simulated using an ab initio calculation based on density functional theory (DFT) within the generalized gradient approximation. The calculations revealed the theoretical lattice parameter, density of states, refractive index, and elastic constants as a function of carbon and nitrogen content. TaC(x)N(y) films were subsequently produced on Si wafers using unbalanced magnetron sputtering. The structural, optical, and mechanical properties were measured using x-ray diffraction/transmission electron microscopy, vacuum ultraviolet spectroscopic ellipsometry, and nanoindentation, respectively. The computational and experimental properties were compared. The lattice parameter, the energy of the 2p bands in the density of states, and the energy of the interband transitions were found to decrease with increasing C content. No significant changes in the elastic constants were observed as a result of substituting N atoms with C atoms. The hardness and the elastic modulus were in the 40 and 380 GPa range, respectively. The experimental Young's modulus was much smaller than the computational one and this discrepancy was attributed to the nanocrystalline nature of the films. Also, the elastic constants were found to decrease dramatically for over-stoichiometric films.

11.
Cardiovasc Surg ; 11(4): 273-6, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12802262

ABSTRACT

OBJECTIVES: To define the natural history of ectatic abdominal aortas and to assess the clinical need for follow-up. DESIGN: Abdominal aortas were considered ectatic if they were diffusely and irregularly dilated with a diameter less than 3 cm. Ectatic aortas were identified either by AAA screening or as incidental findings. Patients who had only one scan were excluded from the study. Clinical data were analysed. SETTING: Two district general hospitals in Wales and England. SUBJECTS: 116 patients (90 men). RESULTS: : The median age of patients was 71 years (range 48-90). Co-existing risk factors included hypertension (75), IHD (22), PVD (8), diabetes (3), COAD (14), stroke (5), popliteal aneurysm (1), malignant disease (3) and 4 had a family history of AAA. The median follow-up was 24 months (range 5-72). The median and maximum growth rate of the ectatic aortas were 0.65 and 14.4 mm/year respectively. In three patients the expansion rate was more than 5 mm/year. In 22 patients the ectatic aorta became aneurysmal, reaching a diameter greater than 3 cm. There were no ruptures and no elective repairs. Two deaths occurred due to IHD. CONCLUSIONS: : This study demonstrates that if ectatic aortas do expand they do so very slowly. However, 22 of the 116 (19%) became aneurysmal in a follow-up of two years. Once identified ectatic aortas should be scanned at intervals of three years.


Subject(s)
Aortic Aneurysm, Abdominal/etiology , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/pathology , Dilatation, Pathologic/etiology , Dilatation, Pathologic/pathology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Risk Factors
12.
Eur J Surg Oncol ; 29(5): 467-74, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12798753

ABSTRACT

AIMS: To evaluate the investigation and surgical management of primary hyperaldosteronism. Retrospective case note analysis of thirty-three patients who underwent adrenalectomy for primary hyperaldosteronism between 1982 and 2001 and a current relevant literature review. METHODS: The records of twelve male and twenty-one female patients, age range 18 to 81 (mean 48 years) were reviewed. Eleven operations were performed by an open approach and twenty-two laparoscopically. Preoperative investigations included computed tomography (CT), magnetic resonance imaging (MRI), selective venous sampling and seleno-cholesterol isotope scanning, along with biochemical and hormonal assays. Twenty-six benign adenomas, three nodular hyperplastic lesions, one primary adrenal hyperplasia and three functional carcinomas were excised. Mean follow up was 12 months. RESULTS: Patients had a mean blood pressure of 185/107 mmHg for 6.2 years mean duration. The mean severity of hypokalaemia was 2.7 mmol/l. Sensitivity of CT scanning was 85%, and of MRI 86%. Fifty percent of seleno-cholesterol scans were accurate. Mean operating time was 158 min for laparoscopic adrenalectomy whilst open surgery took 129 min (p=0.2, NS). Two cases commenced laparoscopically required open access for control of primary haemorrhage whilst one other bleed was managed via the operating ports. Mean postoperative stay was significantly shorter for the laparoscopic group (3 days compared with 7.9 days, p<0.0001). Thirty day mortality was zero. There were three infective complications in the open group (two chest, one wound) with no postoperative complications in the laparoscopic group. All patients were cured of hypokalaemia, whilst 62% cure of hypertension was achieved. Of those patients whose blood pressure was improved preoperatively by spironolactone 78% were cured by adrenalectomy. Adrenalectomy led to an overall reduction in the mean number of anti-hypertensive medications (2.3 drugs preoperative to 0.6 postoperative, p<0.0001). Of those not cured, 58% had improved blood pressure control requiring less medication on average (1.6 drugs compared with 2.6 drugs, p=0.08). Mean age of patients not cured by surgery was 55 years, whilst those cured was 44 years (p=0.03). CONCLUSIONS: Primary hyperaldosteronism is a rare but important cause of hypertension. Selective venous sampling is a useful tool where investigations are inconclusive and fail to lateralise secretion. Patients with primary hyperaldosteronism enjoy lower complication rates and earlier discharge with the advent of laparoscopic surgery. Most patients will be cured of their hypertension and all of hypokalaemia. Laparoscopic adrenalectomy is now the accepted method of surgery for benign hyperaldosteronism. Those with bilateral disease due to idiopathic hyperaldosteronism (IHA) are not candidates for surgery and should be treated medically.


Subject(s)
Adrenal Gland Neoplasms/surgery , Adrenalectomy , Hyperaldosteronism/surgery , Adenoma/surgery , Adolescent , Adrenalectomy/methods , Adult , Aged , Aged, 80 and over , Carcinoma/surgery , Chi-Square Distribution , Female , Humans , Hyperaldosteronism/complications , Hypertension/etiology , Male , Middle Aged , Retrospective Studies , Statistics, Nonparametric , Treatment Outcome
13.
Surg Endosc ; 16(1): 166-9, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11961631

ABSTRACT

BACKGROUND: Many studies have shown that rectal bleeding is a good indicator of underlying colorectal pathology, and that ost of the lesions in patients presenting with rectal bleeding lie in the left side of the colon [1, 5, 9, 12, 23, 26]. The recent acceptance of the nurse-practitioner by the National Health Service may allow the use of nurse-endoscopists to develop throughout the United Kingdom. This study aimed to audit a unique nurse-led direct-access nurse-endoscopy service with regard to its efficacy and cost effectiveness, and to monitor patient satisfaction and direct referrals from the primary health sector. METHODS: A nurse-led open-access flexible sigmoidoscopy (OAFS) service for patients reporting fresh rectal bleeding was established at our center in February 1996. A prospective audit of sigmoidoscopic findings and a retrospective analysis of referral patterns from local general practitioners were conducted. A questionnaire survey of both patient and general practitioner satisfaction also was conducted at the same time. RESULTS: Since February 1996, 706 patients have been referred to our service. Rectal bleeding was by far the most common cause for referral, representing the dominant symptom in 92% of the referrals received. Although 99% of the patients underwent a complete sigmoidoscopic examination, 16% of these examinations were limited because of several factors combined. A cause for bleeding was identified in 91% of the patients, with 24% of them experiencing subsequent significant pathology. Of the patients surveyed, 99% were satisfied with the service provided. The results also show nurse-led OAFS to be a more effective use of financial resources, costing $90 less per patient than general practitioner referrals sent to a consultant for further action. CONCLUSIONS: Rectal bleeding is a good indicator of underlying colorectal disease. Most of the significant lesions presenting with this symptom are found in the left side of the colon. A nurse-led OAFS is safe, effective, and acceptable to patients. It also is more cost effective than a consultant-led service.


Subject(s)
Endoscopy/nursing , Nurse Practitioners/trends , Abdominal Pain/diagnosis , Abdominal Pain/nursing , Abdominal Pain/surgery , Adult , Aged , Endoscopy/economics , Female , Forecasting , Gastrointestinal Hemorrhage/diagnosis , Gastrointestinal Hemorrhage/nursing , Humans , Male , Middle Aged , Rectum/surgery , Retrospective Studies , Sigmoidoscopy/nursing
14.
J R Coll Surg Edinb ; 46(2): 108-9, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11329737

ABSTRACT

We report an unusual case of splenogonal fusion in a 10-year-old boy with an undescended left testis. He suffered from congenital limb defects, a known association with splenogonadal fusion, and had originally been admitted for orchidopexy.


Subject(s)
Abnormalities, Multiple , Cryptorchidism/etiology , Spleen/abnormalities , Testis/abnormalities , Child , Cryptorchidism/surgery , Humans , Male , Radionuclide Imaging , Spleen/blood supply , Spleen/diagnostic imaging , Technetium , Testis/blood supply , Testis/diagnostic imaging
15.
Ann R Coll Surg Engl ; 82(6): 424-7, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11103164

ABSTRACT

Smoking is a major health problem in Great Britain and cigarette consumption is rising. Although there are studies concerning the smoking habits of hospital physicians, nurses and oral and maxillofacial surgeons, little is known about the smoking habits of vascular surgeons and the advice given by them to their patients. A questionnaire survey was conducted involving 422 members of the Vascular Surgical Society of Great Britain and Ireland. The response rate was 74%. The median age of responders was 51 years (range, 32-69 years) of whom 98% were men. Of responders, 98% routinely advise patients to stop smoking, 10% advise nicotine gum/patch, 39% provide antismoking information sheets, 11% are involved in an antismoking clinic/group and 74% check to see whether patients continue to smoke. The majority of responders would be prepared to offer revascularisation in patients who continue to smoke. Only 8 surgeons (3%) would not advise revascularisation in this group of patients. Only 10% of respondents were current smokers, 37% were ex-smokers and 53% had never smoked. Vascular surgeons, therefore, seem to practise what they preach.


Subject(s)
Attitude of Health Personnel , Medical Staff, Hospital/psychology , Patient Education as Topic , Smoking/adverse effects , Vascular Surgical Procedures , Adult , Aged , Female , Follow-Up Studies , Humans , Male , Medical Staff, Hospital/statistics & numerical data , Middle Aged , Smoking/epidemiology , Smoking Cessation , Surveys and Questionnaires , United Kingdom/epidemiology
16.
Ann R Coll Surg Engl ; 82(5): 331-2, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11041032

ABSTRACT

Most upper and lower gastrointestinal endoscopies in Great Britain and Ireland are performed by surgeons, physicians or radiologists. Since the introduction of the 'nurse endoscopist' by the British Society of Gastroenterology Working Party, few centres in the UK have adopted this policy. We have reviewed the anxiety about nurse practitioner endoscopists among patients and physicians. Finally, the role and future of the nurse practitioner endoscopist in the UK is discussed.


Subject(s)
Nurse Practitioners , Sigmoidoscopy , Attitude of Health Personnel , Humans , Nurse Practitioners/trends , Patient Satisfaction , Physicians, Family/psychology , Sigmoidoscopy/trends , United Kingdom
17.
Br J Surg ; 86(6): 765-70, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10383576

ABSTRACT

BACKGROUND: The aim of this study was to identify the incidence of, and mortality in, patients with a ruptured abdominal aortic aneurysm (AAA) reaching hospital alive in Wales. METHODS: Patients who presented with a ruptured AAA between September 1996 and August 1997 were analysed. Data were collected prospectively by an independent body, observing strict confidentiality. RESULTS: Some 233 patients with a confirmed ruptured AAA were identified, giving an incidence of eight per 100 000 total population. Some 133 patients (57 per cent) underwent attempted operative repair; 85 (64 per cent) of these died within 30 days. Of the 233 patients, 92 were admitted under the care of a vascular surgeon and 141 under a non-vascular surgeon. Vascular surgeons operated on 82 patients (89 per cent), of whom 50 (61 per cent) died, whereas non-vascular surgeons operated on 51 patients (36 per cent), of whom 35 (69 per cent) died. DISCUSSION: This study is unique as it is an independent prospective study of mortality in patients with a ruptured AAA who reached hospital alive. Mortality was independent of the operating surgeon, but vascular surgeons turned down significantly fewer patients than non-vascular surgeons (11 versus 64 per cent, P < 0.001).


Subject(s)
Aortic Aneurysm, Abdominal/mortality , Aortic Rupture/mortality , Aged , Aged, 80 and over , Female , Humans , Incidence , Male , Middle Aged , Prospective Studies , Wales/epidemiology
18.
Environ Manage ; 23(4): 539-549, 1999 May.
Article in English | MEDLINE | ID: mdl-10085386

ABSTRACT

/ Land-use activities affect water quality by altering sediment, chemical loads, and watershed hydrology. Some land uses may contribute to the maintenance of water quality due to a biogeochemical transformation process. These land-use/land-cover types can serve as nutrient detention zones or as nutrient transformation zones as dissolved or suspended nutrients or sediments move downstream. Despite research on the effects of individual land-use/land-cover types, very little has been done to analyze the joint contributions of multiple land-use activities. This paper examines a methodology to assess the relationships between land-use complex and nitrate and sediment concentrations [nonpoint source (NPS) pollutants] in streams. In this process, selected basins of the Fish River, Alabama, USA, were delineated, land-use/land-cover types were classified, and contributing zones were identified using geographic information system (GIS) and remote sensing (RS) analysis tools. Water samples collected from these basins were analyzed for selected chemical and physical properties. Based on the contributions of the NPS pollutants, a linkage model was developed. This linkage model relates land use/land cover with the pollution levels in the stream. Linkage models were constructed and evaluated at three different scales: (1) the basin scale; (2) the contributing-zone scale; and (3) the stream-buffer/riparian-zone scale. The contributing-zones linkage model suggests that forests act as a transformation zone, and as the proportion of forest inside a contributing zone increases (or agricultural land decreases), nitrate levels downstream will decrease. Residential/urban/built-up areas were identified as the strongest contributors of nitrate in the contributing-zones model and active agriculture was identified as the second largest contributor. The regression results for the streambank land-use/land-cover model (stream-buffer/riparian-zone scale) suggest that water quality is highest when passive land uses, such as forests and grasslands, are located adjacent to streams. Nonpassive land uses (agricultural lands or urban/built-up areas) located adjacent to streams have negative impacts on water quality. The model can help in examining the relative sensitivity of water-quality variables to alterations in land use made at varying distances from the stream channel. The model also shows the importance of streamside management zones, which are key to maintenance of stream water quality. The linkage model can be considered a first step in the integration of GIS and ecological models. The model can then be used by local and regional land managers in the formulation of plans for watershed-level management. KEY WORDS: Water quality; Land-use complex; Geographic information system; Nonpoint source pollution; Forested buffers

19.
Trop Gastroenterol ; 20(4): 182-4, 1999.
Article in English | MEDLINE | ID: mdl-10769609

ABSTRACT

Hepatic IVC obstruction though common is usually misdiagnosed because of lack of appreciation of the disease. Patient with chronic disease may develop acute exacerbation, which may be precipitated by surgery or endoscopic procedures. It is a report of a case of chronic IVC disease with acute development of ascites following gallbladder surgery.


Subject(s)
Hepatic Veno-Occlusive Disease/diagnosis , Vena Cava, Inferior/diagnostic imaging , Acute Disease , Adolescent , Chronic Disease , Diagnosis, Differential , Female , Hepatic Veno-Occlusive Disease/diagnostic imaging , Humans , Radiography , Ultrasonography
SELECTION OF CITATIONS
SEARCH DETAIL
...