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Biomedical subjects

G Blackman

Publications and source records attributed to G Blackman.

7 recordsLinked to original sources
PubMed2001

A PCR test to identify bacillus subtilis and closely related species and its application to the monitoring of wastewater biotreatment.

A PCR test based on the 16S rRNA gene was set up that could identify any of the five species of the 'Bacillus subtilis group' (B. subtilis, B. pumilus, B. atrophaeus, B. lichenijormis and B. amyloliquefaciens). The test was directly applicable to single colonies and showed excellent specificity. In the mixed population context of wastewater analysis, direct detection of the target Bacillus species by PCR on either crude or purified DNA extracts had poor sensitivity. When assayed on cell suspensions derived from enriched wastewater samples, sensitivity was increased. Using a simple calibration method, it was possible to estimate the proportion of the target organisms. This method was found suitable for easy monitoring of a wastewater bioaugmentation experiment carried out with a mixture of sporulated Bacillus strains.

Bacillus subtilis↗
PubMed1997

Radiotherapy enhances laser palliation of malignant dysphagia: a randomised study.

BACKGROUND/AIMS: A major drawback of laser endoscopy in the palliation of malignant dysphagia is the need for repeated treatments. This study was designed to test whether external beam radiotherapy would reduce the necessity for repeated laser therapy. PATIENTS/METHODS: Sixty seven patients with inoperable oesophageal or gastric cardia cancers and satisfactory swallowing after initial laser recanalisation were randomised to palliative external beam radiotherapy (30 Gy in 10 fractions) or no radiotherapy. All patients underwent a 'check' endoscopy five weeks after initial recanalisation and were subsequently reendoscoped only for recurrent dysphagia, which occurred in 59 patients. RESULTS: Dysphagia was relieved equally well in both groups and the improvement was maintained with further endoscopic treatment. The initial dysphagia controlled interval and the duration between procedures required to maintain lifelong palliation (treatment interval) increased from five to nine weeks (median) in the radiotherapy group (p < 0.01 both parameters). Radiotherapy was well tolerated in all but three patients. One perforation occurred and two fistulae opened after dilatation in patients who received radiotherapy. CONCLUSION: Additional radiotherapy reduces the necessity for therapeutic endoscopy for a patient's remaining life. It has an important role in relatively well patients who are likely to survive long enough to benefit.

Aged↗
PubMed1993

Double hemibody irradiation (DHBI) in the management of relapsed and primary chemoresistant multiple myeloma.

In view of increasing controversy regarding the role of double hemibody irradiation (DHBI) in the treatment of multiple myeloma, we have analysed the use of this technique at our institution over a 6-year period. Fifty-five patients with multiple myeloma were treated with both upper and lower hemibody irradiation between January 1985 and January 1991; 42 had relapsed post-plateau and 13 were chemoresistant to initial therapy. Fifteen patients received alpha IFN-2b maintenance therapy post-DHBI, at a dose of 3 Mu three times per week, as part of a randomized trial. Ninety-five per cent of patients experienced symptomatic improvement in bone pain post-DHBI, 21% of whom discontinued opiate analgesics altogether; 63% had a minor biochemical response and 38% had a partial biochemical response. The overall survival (OS) and progression free survivals (PFS) in all patients were 11 months and 8 months respectively. No significant difference was noted in either OS or PFS, according to whether patients were chemoresistant or had relapsed post-plateau. alpha IFN did not appear to prolong survival (OS or PFS) post-DHBI. Cytopenia was a significant problem, such that only 60% of patients had counts adequate enough to be eligible for alpha IFN. We conclude that DHBI is an effective treatment in patients with relapsed multiple myeloma and in those who are chemoresistant to initial therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Radiation enhancement of laser palliation for advanced rectal and rectosigmoid cancer: a pilot study.

Laser palliation for advanced rectal or rectosigmoid cancer requires repeat treatments every four to six weeks. Thirteen patients (seven men, six women) age range 65-91 (median 81) received additional external beam radiotherapy in an attempt to reduce the frequency of laser treatments required. After successful laser recanalisation, patients were treated with a dose of 30-55 Gy in 10-20 fractions. Bowel symptoms were well controlled for prolonged periods in 11 patients (85%) and further laser procedures were only required every 19 weeks median (range 6-53 weeks). The laser energy required after radiotherapy was only 800 J/month (median). Survival was 14 months (median, range 2.5-20 months) for the seven patients who have died. Seven patients received laser treatment only for three months or more (median 14 weeks, range 13-39). In this group control of symptoms required procedures every four weeks (median) before radiotherapy and 20 weeks (median) afterwards. The laser energy required before radiotherapy was 15,000 J/month and 2000 J/month afterwards (Wilcoxon rank sum test, p < 0.01 for both). Radiotherapy was well tolerated in all but one patient. Three patients developed strictures after radiotherapy but all were dealt with endoscopically. There were no complications solely due to endoscopic procedures. Additional radiotherapy enhances laser palliation for inoperable rectal or rectosigmoid cancer.

Aged↗
PubMed1992

Radiation enhancement of laser palliation for malignant dysphagia: a pilot study.

Laser therapy offers rapid relief of dysphagia for patients with cancers of the oesophagus and gastric cardia but repeat treatments are required approximately every five weeks to maintain good swallowing. To try to prolong the treatment interval, 22 elderly patients were given additional external beam radiotherapy. Nine had squamous cell carcinoma and 13 adenocarcinoma: five had documented metastases. Six received 40 Gy and 16,30 Gy in 10-20 fractions. A 'check' endoscopy was performed three weeks after external beam radiotherapy. Dysphagia was graded from 0-4 (0 = normal; 4 = dysphagia for liquids). The median dysphagia grade improved from 3 to 1 after laser treatment. This improvement was maintained in the 30 Gy group but there was a noticeable deterioration in three of those who had received the higher radiation dose. A lifelong dysphagia grade of 2 or better was enjoyed by 14 of 16 patients in the 30 Gy group but only two of six in the 40 Gy group. The dysphagia controlled interval was 9 weeks (median) after check endoscopy and subsequent endoscopic procedures were required every 13 weeks to maintain good swallowing. There were no endoscopy related complications. Combined treatment is a promising approach for reducing the frequency of endoscopic treatments. The 30 Gy dose seems more appropriate and may prolong survival. A randomised study to test these conclusions is in progress.

Aged↗
PubMed1987

Concurrent daily cisplatin and radiotherapy in locally advanced squamous carcinoma of the head-and-neck and bronchus.

In order to exploit the cytotoxic and radiosensitising actions of cis-platinum, we have treated 35 patients with locally advanced squamous cell carcinoma of the bronchus or head-and-neck. Each patient underwent radical irradiation (60 Gy/30 fractions over 6 weeks) with daily low-dose intravenous cisplatin (10 mg absolute dose per day) administered within 30 min of each daily radiation fraction. Total dose of cisplatin was 300 mg over 6 weeks. Although treatment was complicated by nausea in almost all patients and transient renal dysfunction in the majority, 27 patients completed treatment and renal function returned to normal or near normal in almost all cases. There was no obvious enhancement of pulmonary or skin toxicity, beyond what would have been expected from treatment with radical radiotherapy alone. There were two treatment-related deaths from renal failure. The response rate was high: all patients achieved at least a partial response, and in head-and-neck sites, there were nine complete responders and seven partial responders. Of the initial 35 patients, of whom all but two had advanced inoperable disease, 11 have died and 21 remain in continuous remission, 8-120 weeks from the start of treatment (median 55 weeks).

Carcinoma, Squamous Cell↗