Haemodynamic and metabolic effects of atenolol in patients with angina pectoris.

Myocardial substrate extraction, coronary sinus flow, left ventricular pressure, and cardiac output were measured in 11 patients with angina pectoris at three pacing rates before and after atenolol (0.2 mg/kg). Left ventricular pressures, and the product of systolic pressure time index and heart rate did not change, but max dP/dt and KV max fell after atenolol. Only at the lowest pacing rate did the drug reduce cardiac output. Coronary sinus blood flow and myocardial oxygen uptake did not change after atenolol. At the highest pacing rate before atenolol four patients developed angina, accompanied by a rise in end-diastolic pressure. After atenolol angina was abolished in three, but the end-diastolic pressure still rose at the highest pacing rate. Myocardial lactate extraction ratio fell as heart rate increased, and was lower in the patients who developed angina. After atenolol, lactate extraction ratio increased significantly at the highest and lowest pacing rates. Myocardial pyruvate extraction rose after the drug. Arterial concentrations of hydroxybutyrate and acetoacetate fell after atenolol, but the decrease in their extraction was not significant. Myocardial extraction of free fatty acids was related to arterial concentration, which fell after atenolol. The changes in lactate and pyruvate extraction after atenolol were related inversely to changes in arterial free fatty acid concentration suggesting that the improvement in myocardial metabolism could have been secondary to reduced peripheral lipolysis. The increase in lactate extraction was associated with relief of angina, but did not abolish the rise in end-diastolic pressure induced by pacing.     

Mirex incorporation in the environment: Uptake in aquatic organisms and effects on the rates of photosynthesis and respiration

Exposure of selected aquatic invertebrates to mirex reveals species variability in uptake which is generally a function of exposure period and mirex concentration. The metabolic effects examined relate to photosynthesis and respiration rates. Dissolved oxygen changes, in light and dark bottles containing naturally occurring plankton populations previously exposed to 1 ppb mirex, show progressive photosynthetic inhibition in time from 16% at 6 days exposure to 33% at 18 days exposure. Pure culture of the phytoplankton,Chlamydomonas sp., exhibits a 55% photosynthetic reduction after exposure to 1 ppm mirex for 168 hours. Respiration rates of plankton,Physa gyrina (pond snail),Gambusia affinis (mosquitofish), andLepomis macrochirus (sunfish) demonstrate an initial increasing trend to a maximum of 62%, at low concentration of mirex or during early incubation period, but decrease by as much as 50%, at elevated concentration or extended exposure at low concentration.     

The kinase Mirk/Dyrk1B mediates cell survival in pancreatic ductal adenocarcinoma

Ductal adenocarcinoma of the pancreas is almost uniformly lethal as this cancer is invariably detected at an advanced stage and is resistant to treatment. The serine/threonine kinase Mirk/Dyrk1B has been shown to be antiapoptotic in rhabdomyosarcomas. We have now investigated whether Mirk might mediate survival in another cancer in which Mirk is widely expressed, pancreatic ductal adenocarcinoma. Mirk was an active kinase in each pancreatic cancer cell line where it was detected. Mirk knockdown by RNA interference (RNAi) reduced the clonogenicity of Panc1 pancreatic cancer cells 4-fold and decreased tumor cell number, showing that Mirk mediates survival in these cells. Mirk knockdown by synthetic duplex RNAis in Panc1, AsPc1, and SU86.86 pancreatic cancer cells induced apoptosis and enhanced the apoptosis induced by gemcitibine. Mirk knockdown did not increase the abundance or activation of Akt. However, four of five pancreatic carcinoma cell lines exhibited either elevated Mirk activity or elevated Akt activity, suggesting that pancreatic cancer cells primarily rely on Mirk or Akt for survival signaling. Mirk protein was detected by immunohistochemistry in 25 of 28 cases (89%) of pancreatic ductal adenocarcinoma, with elevated expression in 11 cases (39%). Increased expression of Mirk was seen in pancreatic carcinomas compared with primary cultures of normal ductal epithelium by serial analysis of gene expression and by immunohistochemistry. Thus, Mirk is a survival factor for pancreatic ductal adenocarcinoma. Because knockout of Mirk does not cause embryonic lethality, Mirk is not essential for normal cell growth and may represent a novel therapeutic target.     

Frontoethmoidal mucocele with intraorbital extension: an unusual cause of diplopia

Frontoethmoidal mucoceles are pseudo-cystic lesions which may present with orbital symptoms. A case of frontoethmoidal mucocele in an elderly lady is described who presented with diplopia primarily and was diagnosed with CT scan regarding primary pathology and intraorbital extension. Recovery followed surgical excision and orbital clearance.     

Radiation exposure of trainee anaesthetists

This prospective study was conducted to determine the level of radiation exposure of trainee anaesthetists working in urology, orthopaedics and radiology environments. Anaesthetists wore lithium fluoride thermoluminescent dosimeter (TLD) badges over a 6-month period. The position of badges was standardised at the collar site (TLD1) and at waist level (TLD2). Area specific dosimeters were used and exchanged between anaesthetists. Of a total of 723 procedures, anaesthetists were exposed to radiation in 33% of procedures in orthopaedics, 30% in urology and 39% in radiology. The mean (SD) exposure time to radiation per case was significantly greater in orthopaedics than in urology (9.2 (4) min vs. 4.2 (2) min). The radiation exposure per case was highest in radiology (19.2 (22) min). The net combined exposure over a 6-month period was 0.2177 mSv in urology, 0.4265 mSv in orthopaedics and 3.8457 mSv in radiology. The combined exposure was less than the 20 mSv recommended as the maximum exposure per year. Our data does not support the need for routine dosimetric monitoring of anaesthetists working in the above settings.     

Renal stones in children in Pakistan

One hundred and fifty children up to the age of 12 years with documented evidence of renal or ureteric stones were studied between July 1973 and June 1983. The peak age group was between 10 and 12 years, the male to female ratio being 1.9:1. Abdominal pain was the commonest presenting symptom (66.6%). Asymptomatic stones or vague symptoms in 23 patients warrant a higher index of suspicion of renal stone disease in children. Thirty patients had associated renal insufficiency. One third of the children had a positive urine culture, Proteus spp. being the commonest organism. Congenital anomalies of the urinary tract were seen in 12% of patients. In the majority (59%), aetiological factors related to stone formation could not be identified. One hundred and thirty patients underwent surgery for removal of stones. Analysis of calculi by X-ray diffraction and infrared spectroscopy revealed that stones were predominantly of mixed type, calcium oxalate being the commonest compound. The overall recurrence rate following surgical removal was 15%.     

The effects of comfort care on the pain response in preterm infants undergoing screening for retinopathy of prematurity

OBJECTIVE: The aim of the study was to determine if pain and distress during the retinopathy of prematurity (ROP) screening examination could be ameliorated by providing comfort care. STUDY DESIGN: This study was a prospective, randomized, controlled trial of 30 stable preterm infants who underwent initial ROP screening examinations. Fourteen study infants were swaddled, held, and given 24% sucrose solution during the examination. Sixteen controls were examined while lying in their cribs. Vital signs (i.e., pulse rate, respiratory rate, and oxygen saturation), crying time, and time for the vital signs to return to baseline values were recorded at different times during the examination. RESULTS: The vital signs did not vary significantly between the two groups. The participants in the control group had a trend of longer crying time, but this trend did not reach a level of statistical significance. In addition, The time required for the vital signs to return to their baseline values did not vary significantly. CONCLUSION: ROP screening is very distressful for preterm infants. The routine use of comfort care to reduce pain during the examination could not be supported by this study.