Effects of bait age, larval chemical cues and nutrient depletion on colonization by forensically important Calliphorid and Sarcophagid flies.

Species colonization patterns on corpses and the frequency of carrion fly oviposition and larviposition are affected by decomposition stage and previous maggot colonization. This study investigated these effects on meat bait colonization by Victorian Diptera of forensic importance. Bait treatments were: 'aged' (aged for 4 days at 22 °C, allowing some decomposition); 'nutrient-depleted' [aged for 4 days at 22 °C with feeding Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) larvae]; 'extract' (fresh bait mixed with liquid formed by feeding C. vicina larvae), and 'fresh' (untreated control bait). Statistical analysis (α = 0.05) revealed that colonization frequency differed significantly among treatments (Welch's F(3,18.83) = 4.66, P < 0.05). Post hoc tests showed that fresh and extract baits were colonized extensively throughout the experiment with no significant difference, whereas the colonization of nutrient-depleted baits was significantly lower. This suggests that larval digestive enzymes, larval excreta and cuticular hydrocarbons have less effect on colonizing Diptera than the nutritional content of meat. The colonization of aged baits did not differ significantly from that of fresh, extract or nutrient-depleted baits. A further experiment testing 'very aged' (aged for 8 days at 28 °C), 'larvae-added' (fresh bait with C. vicina larvae added before placement) and 'fresh' (untreated control) baits revealed that very aged baits were colonized significantly less frequently than either fresh or larvae-added baits (Welch's F(2, 6.17) = 17.40, P < 0.05).

Anemia and nutritional status of pre-school children in Kerala.

A study on the pattern of anemia and its relation to nutritional status and dietary habits was conducted among 3633 pre-school children of 108 selected anganwadi centers in rural areas of Kerala State during the period 1996 to 1998. Children were invited with their parent or guardian. Capillary blood was collected from each child and hemoglobin was estimated by cyanomethemoglobin method. Weight and height of children were taken for assessing their nutritional status. The information regarding their age, sex, clinical condition and dietary habits was collected in a performa through an interview. Chi-square test was used to assess the relationship of anemia to sex, dietary habits, and nutritional status. For multivariate analysis logistic regression model was employed. The prevalence of anemia was 11.4%. The percentage of anemic children among male and female children was 10.25 and 12.55 respectively and statistical analysis showed that female children were more susceptible to anemia. Normal nutritional status was seen among 46.7% of the children. When 187 (11.78%) of the mild undernourished children were anemic, the percentage anemic among the moderate undernourished children was 57 (16.37%). Moderate under nutrition and anemia showed a significant association. Anemia was reported among both vegetarians and non-vegetarians. Among 927 vegetarians, 86 (9.27%) were anemic and among 2,706 non-vegetarians, 328 (12.1%) were anemic. Dietary survey revealed that, consumption of iron sources, whether haem or non-haem, was below the recommended level. Undernutrition can be attributed as the major reason for nutritional anemia. Changes in eating behaviour could have potentially affected the iron bio-availability.

Differential lung physiotherapy using a double lumen tube in flail chest and refractory lung atelectasis.

The management of refractory lung atelectasis in a patient with flail chest can be difficult. Treatment of lung atelectasis is complicated by practical problems with the application of chest physiotherapy, postural drainage and incentive spirometry. Although double lumen endotracheal tubes have been used in such cases for the purpose of differential lung ventilation, the use of differential lung physiotherapy has not been reported before. This report describes the successful application of this technique in a patient with flail chest and refractory lung atelectasis.

Cytogenetic effects of energetic ions with shielding.

In order to understand the effects of shielding on the induction of biological damages by charged particles, we conducted experiments with accelerated protons (250 MeV) and iron particles (1 GeV/u). Human lymphocytes in vitro were exposed to particle beams through polyethylene with various thickness, and chromosomal aberrations were determined using FISH technique. Dose response curves for chromosome aberrations were obtained and compared for various particle types. Experimental results indicated that for a given absorbed dose at the cell, the effectiveness of protons and iron particles in the induction of chromosomal aberrations was not significantly altered by polyethylene with thickness up to 30-cm and 15-cm respectively. Comparing with gamma rays, charged particles were very effective in producing complex chromosomal damages, which may be an important mechanism in alterating functions in non dividing tissues, such as nervous systems.

DNA damage and repair in oncogenic transformation by heavy ion radiation.

Energetic heavy ions are present in galactic cosmic rays and solar particle events. One of the most important late effects in risk assessment is carcinogenesis. We have studied the carcinogenic effects of heavy ions at the cellular and molecular levels and have obtained quantitative data on dose-response curves and on the repair of oncogenic lesions for heavy particles with various charges and energies. Studies with repair inhibitors and restriction endonucleases indicated that for oncogenic transformation DNA is the primary target. Results from heavy ion experiments showed that the cross section increased with LET and reached a maximum value of about 0.02 micrometer2 at about 500 keV/micrometer. This limited size of cross section suggests that only a fraction of cellular genomic DNA is important in radiogenic transformation. Free radical scavengers, such as DMSO, do not give any effect on induction of oncogenic transformation by 600 MeV/u iron particles, suggesting most oncogenic damage induced by high-LET heavy ions is through direct action. Repair studies with stationary phase cells showed that the amount of reparable oncogenic lesions decreased with an increase of LET and that heavy ions with LET greater than 200 keV/micrometer produced only irreparable oncogenic damage. An enhancement effect for oncogenic transformation was observed in cells irradiated by low-dose-rate argon ions (400 MeV/u; 120 keV/micrometer). Chromosomal aberrations, such as translocation and deletion, but not sister chromatid exchange, are essential for heavy-ion-induced oncogenic transformation. The basic mechanism(s) of misrepair of DNA damage, which form oncogenic lesions, is unknown.

Postoperative epidural infusion of a mixture of bupivacaine 0.2% with fentanyl for upper abdominal surgery. A comparison of thoracic and lumbar routes.

Thirty-three patients who had undergone elective open cholecystectomy were studied in a prospective, randomised comparison of thoracic (n = 17) and lumbar (n = 16) epidural routes of administration of a mixture of bupivacaine 0.2% with fentanyl 10 micrograms.ml-1 for postoperative pain. Pain relief, cardiovascular stability, respiratory rate and side effects were assessed by a 'blinded' observer at specific times in the 24 h study period. The thoracic epidural route proved significantly more reliable than the lumbar and provided effective analgesia in all patients (p < 0.05). This was not accompanied by significant hypotension or respiratory depression. The incidence of side effects attributable to use of the lumbar epidural route was significantly higher than with the thoracic route (p < 0.05). This study supports the use of the thoracic epidural route for postoperative pain management after upper abdominal surgery.

Thoracic epidural analgesia compared with patient controlled intravenous morphine after upper abdominal surgery.

Twenty-one ASA I or II patients undergoing upper abdominal surgery were studied for 24 hours after operation. They were entered into a prospective, randomised study of patient-controlled intravenous morphine compared with continuous thoracic epidural fentanyl combined with 0.2% bupivacaine. Pain relief was superior in the bupivacaine series (P < 0.05) throughout the 24 hour study period and this was associated with significantly greater pulmonary ventilation compared with the PCA series. Forced expiratory parameters were reduced in both series after the operation but significantly less so in the epidural group. There was a reduced incidence of emetic symptoms in the epidural group (P < 0.05) but the incidence of other minor side effects did not differ significantly. Thoracic epidural fentanyl/bupivacaine results in significantly better analgesia than patient-controlled intravenous morphine.

Thoracic epidural infusion for postoperative pain relief following abdominal aortic surgery: bupivacaine, fentanyl or a mixture of both?

Thirty patients who had undergone elective abdominal aortic surgery were studied in a prospective, randomised double-blind comparison of thoracic epidural 0.2% bupivacaine alone, thoracic epidural fentanyl alone and thoracic epidural 0.2% bupivacaine combined with fentanyl. Pain relief, pulmonary function, cardiovascular stability and side effects were assessed. Pain relief was excellent in the combined bupivacaine-fentanyl series, being significantly better than the other groups (p less than 0.05) during the entire study period and was not accompanied by hypotension. Forced expiratory parameters were reduced in all groups throughout the study to 50-60% of the pre-operative values, but there were no significant differences between groups. The incidence of side effects attributable to either epidural bupivacaine or fentanyl was low. This study supports the increasing use of epidural infusion analgesia for postoperative pain management after abdominal surgery.

Continuous thoracic epidural fentanyl for post-thoracotomy pain relief: with or without bupivacaine?

Twenty-five ASA 1 or 2 patients undergoing thoracotomy were entered into a prospective, randomised, double-blind study comparing thoracic epidural fentanyl alone and thoracic epidural fentanyl combined with 0.2% bupivacaine. Pain relief, pulmonary function and cardiovascular stability were assessed. Pain relief was superior in the bupivacaine series (p less than 0.05) during the first day after operation and this was accompanied by better oxygenation (p less than 0.05); the difference did not persist into the second day. Forced expiratory variables were reduced in both series to 50-60% of the values before operation throughout the study (p less than 0.05) and differences did not occur between the groups. The incidence of side effects attributable to epidural fentanyl was high, but hypotension did not occur. Small doses of bupivacaine administered together with fentanyl into the thoracic epidural space improve analgesia without causing hypotension.

Studies of drugs given before anaesthesia XXVI: lorazepam.

Lorazepam has been studied as preanaesthetic medication given by mouth, i.m. and i.v. Sediation and side-effects and the incidence of anterograde amnesia in patients having a standard operation under methohexitone-nitrous oxide-oxygen anaesthesia were assessed. In a preliminary study of three i.m. (2-, 4- and 8-mg) and six oral (1-,2-,2.5-,4-,5- and 8-mg) doses, the optimum dose was found to be 4 mg for patients with an average weight of 60 kg. This dose was studied in detail when given by all three routes and compared with the commercially available 2.5- and 5-mg tablets. Even when given i.v., there was a delay of 30-40 min in the onset of maximum sedative effect and drowsiness persisted for at least 4 h. Although the onset of action by i.m. injection was slightly faster than when the drug was given by mouth this advantage was more than offset by the high frequencies of pain at the site of injection and restlessness which persisted for 20-40 min. Oral lorazepam in doses of 2.5-5.0 mg was a reliable, effective sedative which could be recommended for routine preanaesthetic medication, provided rapid recovery was not essential. Its soporific effect was accompanied by an appreciable incidence of anterograde amnesia.

Relative amnesic actions of diazepam, flunitrazepam and lorazepam in man.

1. Ten postcards were shown to groups of ten to twenty patients over 60, 90 or 270 min after intravenous injection of saline, diazepam (10 and 20 mg), flunitrazepam (1 and 2 mg) and lorazepam (4 mg). 2. Incidence of amnesia was estimated by the patients' ability to recall or recognize these cards and to recall various other incidents in the para-anaesthetic period. 3. The use of a dummy confirmed the reliability of the method of testing for amnesia in man. 4. Flunitrazepam produced a dose-related incidence of amnesia slightly longer than with the equivalent (1 x 10) dose of diazepam. 5. The onset of amnesia was slower with lorazepam (4 mg) but appeared to last for up to four hours. 6. This amnesic action of lorazepam was paralleled by a useful sensitive effect but there was no similar correlation for diazepam and flunitrazepam. 7. With three drugs of different duration of action it should be possible to produce amnesia for any required clinical situation.