Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
Add more filters










Publication year range
1.
J Interferon Cytokine Res ; 27(5): 377-82, 2007 May.
Article in English | MEDLINE | ID: mdl-17523869

ABSTRACT

The effect of foods on the production of interferon-alpha (IFN-alpha) is currently unknown. Garlic (Allium sativum) used as a folk medicine is reported to stimulate nitric oxide (NO) production. We investigated the systemic increase of NO due to the ingestion of garlic on the plasma IFN-alpha level in normal volunteers. Normal volunteers (10 groups, 10 in each group) ate 2 g fresh garlic, and plasma NO and IFN-alpha levels were determined after 2 and 4 h. The participants were also asked to eat garlic for various periods of time, and plasma NO and IFN-alpha were similarly assayed. Ingestion of 2 g fresh, but not boiled, garlic was found to increase the basal plasma level of NO from 2.7 +/- 0.1 microM to 8.76 +/- 0.21 microM at 2 and 4 h, respectively. The basal plasma IFN-alpha level increased from 9.51 +/- 0.26 nM to 46.3 +/- 1.2 nM in normal volunteers (n = 10) at the same time. The chronic eating of garlic was found to maintain IFN-alpha at high levels for at least 7 days. The exposure of neutrophils to garlic in vivo or in vitro, which also stimulated synthesis of NO in these cells, was found to stimulate IFN-alpha synthesis as measured by the stimulation of IFN-alpha mRNA synthesis. Thus, consumption of garlic resulted in stimulated synthesis of NO and, in turn, IFN-alpha in humans, which could be beneficial in viral or proliferative diseases.


Subject(s)
Garlic , Interferon-alpha/biosynthesis , Adult , Enzyme-Linked Immunosorbent Assay , Female , Food , Humans , Interferon-alpha/blood , Male , Middle Aged , Neutrophils/drug effects , Nitric Oxide/biosynthesis , Nitric Oxide/blood , RNA, Messenger/biosynthesis , Time Factors
2.
Singapore Med J ; 40(8): 513-8, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10572490

ABSTRACT

AIM: The purpose of this study was to retrospectively detect Aspergillus antigens in sera obtained from immunocompromised host using an in-house modified double antibody sandwich ELISA. MATERIALS AND METHODS: The ELISA employed the use of polyclonal antibodies raised against a water-soluble (WS) mycelial component of a clinical isolate of Aspergillus fumigatus. Rabbit and guinea-pig anti-WS antibodies were used as the capture and detector antibodies respectively. This was followed by the addition of anti-guinea pig antibodies conjugated to horse radish peroxidase and orthophenylenediamine. RESULTS: Of 143 specimens obtained from 140 patients, only 5 (3.5%) specimens demonstrated the presence of antigen. The 5 antigen-positive sera were from three patients. One was a confirmed case of paranasal aspergillosis and the other two were probable cases of invasive aspergillosis. CONCLUSION: The clinical validity of the ELISA should be determined by prospective detection of Aspergillus antigens in multiple serum samples collected from proven cases of invasive aspergillosis.


Subject(s)
Antibodies, Fungal/analysis , Aspergillosis/diagnosis , Aspergillus fumigatus/isolation & purification , Enzyme-Linked Immunosorbent Assay/methods , Fungemia/diagnosis , Immunocompromised Host , Adolescent , Aspergillosis/immunology , Aspergillus fumigatus/immunology , Child , Child, Preschool , Female , Fungemia/immunology , Humans , Male , Middle Aged , Reproducibility of Results , Retrospective Studies , Sampling Studies , Sensitivity and Specificity
3.
Australas Radiol ; 42(3): 250-1, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9727258

ABSTRACT

Adrenal tumours are either functioning or non-functioning. Non-functioning adrenal tumours are generally asymptomatic and usually of enormous proportions at the time of presentation. A case is presented here of a patient with a huge right adrenal haemangioma which was successfully treated surgically. This unusual tumour was 25 cm in diameter, was well encapsulated and weighed 4 kg. The literature pertaining to this interesting case is reviewed.


Subject(s)
Adrenal Gland Neoplasms/diagnostic imaging , Hemangioma/diagnostic imaging , Adrenal Gland Neoplasms/surgery , Female , Hemangioma/surgery , Humans , Middle Aged , Tomography, X-Ray Computed
4.
Med J Malaysia ; 53(3): 284-7, 1998 Sep.
Article in English | MEDLINE | ID: mdl-10968168

ABSTRACT

Three children aged 3-11 years had ultrasonography of the urinary tract for the investigation of dysuria and haematuria. A bladder mass was seen in these 3 children. One child had computed tomography scan, cystoscopy and bladder biopsy because rhabdomyosarcoma was considered. The biopsy revealed an inflammatory process. The urine culture of the other 2 children revealed E. coli. On ultrasonography, the inflammatory mass may appear homogeneously hypoechoic or may contain moderate level echoes. The mucosal surface of the mass may be smooth or lobulated. It is important to consider an infective cause for a bladder mass in children because computed tomography, cystoscopy and biopsy may be avoided.


Subject(s)
Cystitis/diagnostic imaging , Urinary Bladder Neoplasms/diagnostic imaging , Anti-Infective Agents, Urinary/therapeutic use , Child , Child, Preschool , Cystitis/complications , Cystitis/drug therapy , Diagnosis, Differential , Female , Hematuria/etiology , Humans , Male , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Ultrasonography , Urination Disorders/etiology
5.
Med J Malaysia ; 52(2): 178-80, 1997 Jun.
Article in English | MEDLINE | ID: mdl-10968079

ABSTRACT

This is a case report of a pseudoaneurysm due to Salmonella aortitis in a 52 year old man. The condition is rare and represents one of the few cases reported in Malaysia. The diagnosis was made preoperatively by ultrasonography and computed tomography. This was confirmed at surgery where there was a 3 cm defect at the posterior wall of the aorta at L2/3 level. The aneurysmal sac extended to the retrocrural space at the 12th vertebra level cranially on the right side to the lower border of the 3rd lumbar vertebra caudally. It had a smooth fibrous wall and contained a mixture of organised haematoma and pus. At operation the aneurysm was excised, the affected region was carefully debrided and the aorta grafted with an in-situ in-lay graft. Antibiotic therapy was instituted until clinical response was evident, leukocytosis was reduced and blood culture was negative. However 4 months after surgery, the patient returned in irreversible shock and succumbed to disseminated intravascular coagulation secondary to massive upper gastrointestinal haemorrhage from an aortoduodenal fistula.


Subject(s)
Aneurysm, False/surgery , Aneurysm, Infected/surgery , Aortic Aneurysm/surgery , Salmonella Infections/surgery , Humans , Male , Middle Aged
6.
Med J Malaysia ; 51(4): 457-61, 1996 Dec.
Article in English | MEDLINE | ID: mdl-10968034

ABSTRACT

The main objective of this study is to illustrate the role of ductography in the management of nipple discharge. Thirty-six patients had ductography for the investigation of blood-stained or serous nipple discharge. The ductogram findings were reviewed. Ductography showed an intraductal lesion in 13 patients, duct ectasia in 16 and normal ducts in 7. Fourteen patients had surgery. Eight had preoperative ductography using a mixture of methylene blue and contrast media. Histology revealed 5 cases of duct papilloma, 2 cases of epithelial hyperplasia, 4 cases of fibrocystic change and 3 cases of duct ectasia. Twenty had follow-up without surgery and of these, the nipple discharge ceased in 11 patients. Two patients did not come for follow-up. Ductography has a significant role in the management of nipple discharge. Firstly, surgery might be averted in patients with normal ducts or duct ectasia on ductography. Secondly, intraductal methylene blue will demonstrate the abnormal ductal system to the surgeon and allow for a less radical surgery.


Subject(s)
Breast Diseases/diagnostic imaging , Mammography , Female , Humans , Nipples/diagnostic imaging
7.
Lupus ; 5(2): 123-8, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8743125

ABSTRACT

Cerebral lupus (CL) is a common cause of morbidity and mortality in patients with SLE. The brain CTs of 27 consecutive adult patients with SLE and various neurological presentations were reviewed. The median age and duration of neurological symptoms at the time of the brain CT were 30 years (range = 14-51 years) and six days (range = 1 day-22 years), respectively. Eleven patients (41%) had normal CTs. The abnormalities in the remaining patients could be divided into six categories: (a) cerebral atrophy alone (two patients); (b) calcification alone (three patients); (c) infarct(s) alone (five patients); (d) cerebral atrophy and calcification (three patients); (e) cerebral atrophy and infarct(s) (one patient) and (f) cerebral atrophy, calcification and infarct(s) (two patients). Altogether eight patients (30%) (age range = 17-47 years) had intracerebral calcification: the globus pallidus was involved in all, putamen in two, head of the caudate nucleus in one, thalamus in one, centrum semiovale in two and cerebellum in three patients. Two patients had extensive calcifications of most of the basal ganglia, centrum semiovale and cerebellum. There was no relationship between the presence/degree of calcification and age of patients/duration or type of neurological presentation. The pathogenesis of cerebral calcification in CL is unknown. Cerebral lupus must now be included in the differential diagnosis of intracerebral calcification.


Subject(s)
Brain Diseases/diagnostic imaging , Brain Diseases/pathology , Calcinosis/pathology , Lupus Erythematosus, Systemic/diagnostic imaging , Lupus Erythematosus, Systemic/pathology , Adolescent , Adult , Atrophy , Brain/diagnostic imaging , Brain/pathology , Brain Diseases/etiology , Calcinosis/diagnostic imaging , Cerebral Infarction/diagnostic imaging , Cerebral Infarction/pathology , Female , Humans , Lupus Erythematosus, Systemic/physiopathology , Male , Middle Aged , Retrospective Studies , Tomography, X-Ray Computed
8.
Med J Malaysia ; 51(1): 136-40, 1996 Mar.
Article in English | MEDLINE | ID: mdl-10967994

ABSTRACT

Three cases of diffuse panbronchiolitis (DPB) occurring in two Malaysian Chinese patients and one Malay patient are reported. They had similar clinical, radiological and physiological features which are characteristic of DPB. The diagnosis in one of the cases was confirmed histologically by transbronchial lung biopsy. These could be the first three cases identified in Malaysia.


Subject(s)
Bronchiolitis/diagnosis , Bronchiolitis/physiopathology , Adult , Bronchiolitis/pathology , Female , Humans , Male , Radiography, Thoracic , Respiratory Function Tests , Tomography, X-Ray Computed
9.
Med J Malaysia ; 51(1): 151-3, 1996 Mar.
Article in English | MEDLINE | ID: mdl-10967999

ABSTRACT

Spinal vascular malformation is an uncommon but potentially treatable cause of myelopathy. We describe two cases of angiographically proven spinal vascular malformation in Malaysia. The first case is a 47-year-old man who had a progressive myelopathy and the second a 60-year-old man with intermittent attacks of transient paraparesis leading to paraplegia. As the clinical presentation of spinal vascular malformation is variable, it should be considered as a cause of patients with myelopathy.


Subject(s)
Arteriovenous Fistula/complications , Dura Mater/blood supply , Paraplegia/etiology , Spinal Cord/blood supply , Angiography , Arteries/abnormalities , Arteriovenous Fistula/diagnostic imaging , Humans , Male , Middle Aged
10.
Med J Malaysia ; 50(1): 82-6, 1995 Mar.
Article in English | MEDLINE | ID: mdl-7752982

ABSTRACT

The sonographic and CT appearances of 9 large cavernous hemangiomas of the liver were studied. On sonography, 6 masses (67%) exhibit heterogenous echo pattern; where in 2 patients the echotexture was a mixture of hypoechoic and isoechoic areas and in 4 patients there are varying amounts of bright hyperreflective areas similar to the texture typical of small hemangiomas. The masses were predominantly hypoechoic in the remaining 3 patients (33%). Incremental bolus or bolus-infusion dynamic CT showed peripheral contrast enhancement of varying intensities and thickness in all patients. The lesions were incorrectly diagnosed as hepatomas in 4 patients, suspected as hemangiomas with a differential diagnosis of hepatomas in 4 patients and an early liver abscess in 1 patient. It is concluded that large cavernous hemangiomas of the liver do not exhibit the typical homogenous hyperreflective echotexture as exhibited by small lesions and they mimic primary and secondary hepatic neoplasms. However, the diagnosis of hemangioma should be entertained when such a mass contains bright hyperechoic areas within its heterogenous echo pattern and exhibit peripheral enhancement on contrast enhanced CT. In addition to correlation with appropriate clinical information, confirmation of diagnosis include delayed scanning during a routine incremental bolus dynamic CT, single-slice dynamic contrast enhanced CT, angiography or isotope scintigraphy and magnetic resonance imaging depending on the availability of facility.


Subject(s)
Hemangioma, Cavernous/diagnostic imaging , Liver Neoplasms/diagnostic imaging , Tomography, X-Ray Computed , Adult , Female , Humans , Male , Middle Aged , Ultrasonography
11.
Br J Rheumatol ; 34(2): 162-5, 1995 Feb.
Article in English | MEDLINE | ID: mdl-7704463

ABSTRACT

We determined the consumption of non-steroidal anti-inflammatory drugs (NSAIDs) and the prevalence of chronic renal impairment and renal papillary necrosis (RPN) in patients with various types of arthritis. Ninety-four patients with chronic arthritis who had consumed more than 1000 capsules and/or tablets of NSAIDs were studied. Renal profiles and radiological investigations such as intravenous urogram (IVU), ultrasonography (US) and computed tomography (CT) were performed to look for evidence of RPN. Twelve patients did not complete the study. Ten of the 82 patients who had completed the study (12.2%) had radiologic evidence of RPN. Five out of 53 patients (9.4%) with rheumatoid arthritis, three out of 11 patients (27.3%) with gouty arthritis and two out of seven patients (28.6%) with osteoarthritis had RPN. Renal impairment (serum creatinine levels of 125-451 mumol/l) was found in 20 patients (24.4%). The patients had consumed 1000-26,300 capsules and/or tablets over a period ranging from 1 yr to more than 30 yr. Patients with chronic arthritis who consume excessive amount of NSAIDs are at risk of developing RPN and chronic renal impairment.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Arthritis/drug therapy , Kidney Diseases/chemically induced , Adult , Aged , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Chronic Disease , Female , Humans , Kidney Papillary Necrosis/chemically induced , Male , Middle Aged , Prospective Studies , Time Factors
12.
Am J Kidney Dis ; 24(1): 17-24, 1994 Jul.
Article in English | MEDLINE | ID: mdl-8023820

ABSTRACT

The risk of renal papillary necrosis and renal dysfunction due to the chronic use of nonsteroidal anti-inflammatory drugs (NSAIDs) is unknown. In a prospective study of 259 heavy analgesic users seen in a general medical hospital over an 11-year-period beginning in January 1982, 69 new cases of analgesic nephropathy with renal papillary necrosis were confirmed by intravenous urogram (26.6%), ultrasonography (30.4%), and/or computed tomography (43%). Twenty-nine of these patients (42%) had consumed excessive quantities of NSAIDs alone; an additional nine patients (13%) had consumed NSAIDs predominantly in combinations with paracetamol, aspirin, phenacetin, caffeine, and/or traditional herbal medications. Of those patients who consumed NSAIDs alone, 17 had consumed only a single type of NSAID and the remaining 12 had consumed multiple types of NSAIDs. The amount of NSAIDs administered ranged from 1,000 to 26,600 capsules or tablets over a 2- to 25-year period. Renal impairment (serum creatinine, 126 to 778 mumol/L) was noted in 26 of these 38 patients (64.8%). The reasons given for consuming NSAIDs include gouty arthritis (18 patients), osteoarthritis (seven patients), rheumatoid arthritis (six patients), chronic headache (three patients), gouty arthritis plus chronic headache (three patients), and chronic backache (one patient). All patients were prescribed these drugs and were followed medically. The occurrence of analgesic nephropathy was predominantly in males (male to female ratio, 1.9:1). Most of the patients did not have the characteristic psychological profile attributed previously to analgesic abuse nephropathy. Associated addictive habits, such as the use of psychotropic drugs and sleeping tablets, purgative abuse, and alcoholism, were absent.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Kidney Failure, Chronic/chemically induced , Kidney Medulla/drug effects , Adult , Aged , Female , Humans , Kidney Failure, Chronic/diagnostic imaging , Kidney Medulla/diagnostic imaging , Kidney Medulla/pathology , Male , Middle Aged , Necrosis/chemically induced , Prospective Studies , Radiography , Time Factors , Ultrasonography
13.
Med J Malaysia ; 49(2): 192-4, 1994 Jun.
Article in English | MEDLINE | ID: mdl-8090105

ABSTRACT

The intraoperative localisation of small intestinal bleeding lesions identified at pre-operative angiography has always been difficult, resulting in extensive resections in doubtful cases. We report two patients in whom, at angiography, a small intestinal lesion was noted to be the cause of gastrointestinal haemorrhage. They then underwent superselective mesenteric arterial cannulation at a second angiographic procedure and were operated upon with the angiographic catheter left within the branch responsible for the bleeding. This superselective catheter placement facilitates precise localisation of the bleeding site intraoperatively, enabling limited segmental resection of bowel. Both patients have had no recurrent bleeding episodes.


Subject(s)
Gastrointestinal Hemorrhage/diagnosis , Adult , Catheterization , Humans , Intestinal Mucosa/pathology , Intraoperative Period , Laparotomy , Male , Mesenteric Arteries
14.
Med J Malaysia ; 49(1): 86-9, 1994 Mar.
Article in English | MEDLINE | ID: mdl-8057997

ABSTRACT

A case of symptomatic polycystic liver disease treated by fenestration and segmental liver resection is reported. The intraoperative use of ultrasound to define the plane of liver resection is emphasised. No significant post-operative complication was encountered. The clinical presentation, management and treatment are discussed.


Subject(s)
Cysts/surgery , Hepatectomy/methods , Liver Diseases/surgery , Cysts/diagnosis , Female , Follow-Up Studies , Humans , Liver Diseases/diagnosis , Middle Aged , Monitoring, Intraoperative , Tomography, X-Ray Computed , Treatment Outcome , Ultrasonography, Interventional
15.
Med J Malaysia ; 48(4): 421-6, 1993 Dec.
Article in English | MEDLINE | ID: mdl-8183166

ABSTRACT

Realtime ultrasonography with general purpose sector transducer was used to guide 87 percutaneous biopsies on 82 patients with lesions suspected to be mediastinal masses on plain chest radiographs. In seven patients who had dyspnea the biopsies were done in erect or semi-erect sitting positions. Definitive diagnosis was obtained from 66 lesions (80.5%) where 46 (70.0%) were mediastinal and the remaining 20 lesions (30.0%) arising from the lung. Of the 46 mediastinal lesions where specific diagnosis were made, 42 (91.0%) were anterior and four (0.9%) posterior mediastinal lesions. The majority of these anterior mediastinal masses were lymphomatous nodes followed by germ cell tumours whereas all four posterior mediastinal masses were neurogenic. Of the lung lesions, 19 were primary malignancies. The remaining lung lesion which was located posteriorly was cryptococcus infection. One patient developed massive hemothorax, but subsequently recovered. No significant complications were encountered in the remaining patients. Surgery was carried on 11 patients. There is correlation between definitive diagnosis from percutaneous biopsy and final diagnosis after surgery in 80% of patients. It is proposed that all percutaneous biopsies for thoracic masses which abut the chest wall and cause mediastinal widening on a plain chest radiograph be guided by ultrasound. It can be effectively accomplished with ease and safety even without the use of dedicated biopsy ultrasound probes or biopsy attachments, and on patients in erect or semi-erect positions.


Subject(s)
Mediastinal Neoplasms/diagnosis , Mediastinum/pathology , Adolescent , Adult , Aged , Biopsy , Child , Child, Preschool , Female , Humans , Male , Mediastinal Neoplasms/diagnostic imaging , Mediastinal Neoplasms/pathology , Mediastinum/diagnostic imaging , Middle Aged , Ultrasonography
16.
Headache ; 33(8): 442-5, 1993 Sep.
Article in English | MEDLINE | ID: mdl-8262786

ABSTRACT

The pattern of analgesic use, abuse and incidence of analgesic-associated nephropathy in 79 patients with chronic headache was studied. Sixty-eight of these patients had migraine. Most patients had consumed a combination of analgesics (81%) while 19% had taken single analgesics for their headache. Nonsteroidal anti-inflammatory drugs were the most commonly used analgesics (96.2%) followed by paracetamol (70.9%) and aspirin, phenacetin and caffeine compounds (5.1%). Mefenamic acid was the commonest nonsteroidal anti-inflammatory drug consumed (97.4%). Analgesic abuse which was defined as a minimum total of 1 kg of analgesics such as paracetamol or aspirin, phenacetin and caffeine compounds or 400 capsules/tablets of nonsteroidal anti-inflammatory drugs was noted in 65 patients. Nonsteroidal anti-inflammatory drugs were the most commonly abused analgesics (89.2%) followed by paracetamol (38.5%). Forty-five of the 65 analgesic abusers had an intravenous urogram or ultrasound performed and renal papillary necrosis was documented in one patient. Three (4.6%) of the analgesic abusers had mildly raised serum creatinine levels. Mild proteinuria of less than 1 gm/litre was present in 27.7% of abusers. In conclusion, although analgesic use and abuse is common in patients with chronic headache, the short term incidence of analgesic-associated nephropathy (2.2%) and renal impairment (4.6%) was low. Prolonged observations will be necessary to ascertain the safety of these drugs for long term use.


Subject(s)
Analgesics/adverse effects , Headache/drug therapy , Kidney Failure, Chronic/chemically induced , Migraine Disorders/drug therapy , Analgesics/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Dose-Response Relationship, Drug , Drug Therapy, Combination , Humans , Kidney Function Tests , Long-Term Care , Prospective Studies , Risk Factors , Substance-Related Disorders/complications , Urography
17.
Med J Malaysia ; 48(1): 33-9, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8341170

ABSTRACT

Single gas-containing pyogenic liver abscesses in 11 patients were studied by ultrasound and computed tomography (CT). On ultrasound, all abscesses were predominantly echogenic compared to the normal liver parenchyma. The gas collections appeared as hyperreflective areas arranged in clusters associated with acoustic shadowing and ring-down artifacts. Ten abscesses (90%) had ill-defined margins on ultrasound, causing underestimation of their sizes in these patients. All abscesses were shown to be multiloculated and had clearly defined borders on CT, not appreciated or mistaken for multiplicity of abscesses on ultrasound. Ultrasound may be inadequate in the evaluation of gas-containing liver abscesses, as they have complex echotexture in addition to ring-down artifacts, acoustic shadows and poorly-defined margins; leading to underestimation of abscess size, difficulty in identifying loculations and erroneous interpretation of multiplicity of abscess cavities.


Subject(s)
Gases , Liver Abscess/diagnostic imaging , Adult , Female , Humans , Male , Middle Aged , Suppuration , Tomography, X-Ray Computed , Ultrasonography
18.
Acta Paediatr Scand ; 80(6-7): 735-7, 1991.
Article in English | MEDLINE | ID: mdl-1867096

ABSTRACT

One of the babies in a pair of xiphaomphalopagus conjoined twins developed oliguria, transient rise in serum creatinine and persistent nephrogram on the sixth day of life following injection of radiocontrast medium for computerised axial tomography scanning of the urinary system. The other twin was spared but developed hypertension and "dialysed" the oliguric twin. The renal profiles of both neonates subsequently remained normal until they reached adequate weight for surgical separation at a later date.


Subject(s)
Contrast Media/adverse effects , Kidney Diseases/chemically induced , Twins, Conjoined , Humans , Infant
19.
Can J Microbiol ; 37(4): 265-9, 1991 Apr.
Article in English | MEDLINE | ID: mdl-1913338

ABSTRACT

Vibrio cholerae lysogenic kappa phage was inactivated by X-ray (60 kV) in a dose-dependent manner, the inactivation dose leading to 37% survival (D37) in phosphate-buffered saline (PBS), pH 7.4, being 0.36 kGy. The phages were significantly protected against X-ray irradiation when histidine or cysteine or both were present in PBS or when phages were irradiated in nutrient broth. Maximum protection was offered when both histidine (10.0 mM) and cysteine (10.0 mM) were present in PBS (dose enhancement factor being 4.17). The X-irradiated kappa phages also underwent a small but significant Weigle reactivation and also Weigle mutagenesis in the UV-irradiated V. cholerae host H218Smr. The Weigle factor or the frequency of clear-plaque mutants increased with increasing UV dose, attained a maximum at a UV dose of 2.4 J m-2, and thereafter decreased gradually with a further increase of the UV dose. The X-ray dose (D)--survival (S) curves could be empirically described by the equation S = exp[-(aD + bD2)], where a and b are constants depending on the irradiation conditions, and a good agreement between the theoretical curves and experimental data was obtained.


Subject(s)
Bacteriophages/physiology , Lysogeny/radiation effects , Mutagenesis , Vibrio cholerae , Bacteriophages/genetics , Bacteriophages/radiation effects , Dose-Response Relationship, Radiation , Lysogeny/genetics , Ultraviolet Rays , Vibrio cholerae/radiation effects
SELECTION OF CITATIONS
SEARCH DETAIL
...