Adequate survival of red cells from units "undercollected" in citrate- phosphate-dextrose-adenine-one

The lower limit for the volume of whole blood that may be collected for transfusion into standard blood recipient sets is 405 ml. Each year it is estimated that 82,500 to 161,700 units are drawn which contain between 275 and 405 ml. This study evaluated whether these "undercollected" units would be suitable for transfusion. Twenty normal adults donated both a "standard" unit (450 ml) and an "undercollected" unit (275 ml) in 63 ml of citrate-phosphate-dextrose-adenine-one (CPDA- 1). The units were packed within 4 hours (mean Hct 71%) and stored undisturbed at 4 degrees C for 35 days. Aliquots of 1 to 2 ml of red cells from each unit were then labeled with 51chromium (51Cr) and reinfused into the original donor. The mean 24-hour survival of the 450- ml units was 78.8 percent (SD 12.2, SEM 2.7), while the mean 24-hour survival of the 275-ml units was 87.7 percent (SD 10.7, SEM 2.4; p less than .01). Seven inadvertently undercollected units (mean vol: 295 ml) had a mean 24-hour survival of 91.9 percent. The higher concentration of dextrose and adenine in the undercollected units may improve posttransfusion red cell viability. These data suggest that 275 ml is the minimum acceptable volume for blood donated into CPDA-1.     

Meningeal carcinomatosis in the VX2 rabbit tumor model: detection with Gd-DTPA-enhanced MR imaging

Meningeal carcinomatosis developed in 14 of 14 New Zealand White rabbits after infusion of a VX2 tumor cell suspension into the cisterna magna. All died or were killed 7-15 days after inoculation. Within days of the tumor infusion, magnetic resonance (MR) imaging with gadolinium-diethylenetriaminepentaacetic acid (DTPA) at 0.5 or 1.5 T demonstrated enhancement of the cerebrospinal fluid (CSF) secondary to disruption of the blood-CSF barrier by plaquelike lesions along the meninges. Eventually, meningeal enhancement was observed along the base of the brain and cervical spine. Quantitative assessment of the contrast enhancement on T1-weighted images revealed an increase in mean signal intensity of 213% +/- 130%. Contrast enhancement was not observed in four control animals who received an infusion of cell culture medium. These results demonstrate in an animal model that contrast material-enhanced MR imaging can be used to detect meningeal carcinomatosis by revealing breakdown of the blood-CSF barrier.     

Proximal Cutaneous Necrosis Associated with Small Vessel Calcification in Renal Failure

Cutaneous necrosis with microvascular calcification is a rareand serious complication of chronic renal failure and has beengiven the sobriquet of ‘calciphylaxis’. We describefour dialysis-dependent patients with proximal cutaneous necrosiswho presented with this distinctive clinical syndrome. All ofthe patients were women aged between 40 and 68, and all developedwidespread livedo reticularis followed by painful subcutaneousnodules which progressed to eschar-like lesions of the skin.Microvascular calcitication was seen on radiographs of the limbs,especially at the sites of the cutaneous lesions. Serum phosphorusconcentrations were increased in all the patients (maximallyto between 2 and 3.6 mmol/l), but serum calcium concentrationswere mildly increased in only two patients and only one patienthad hyperparathyroidism. Histological examinations of skin biopsiesin two patients showed cutaneous infarcts. Three patients dieddespite a reduction in serum phosphorus concentration and onepatient improved. The proximal form of ‘calciphylaxis’constitutes a distinct syndrome which can be recognized clinically.     

Drug pretreatment effects in drug induced taste aversions: Effects of dose and duration of pretreatment

The effetiveness of a dose of 3.0 mg/kg methamphetamine in inducing a conditioned taste aversion to saccharin was found to be reduced by chronic pretreatment with the same dose of the drug. The degree of attenuation of the aversive properties of the drug was found to be directly proportional to the duration of pretreatment, a pretreatment regime of 9 or more daily injections completely abolishing the aversive properties of the drug. However, such a regime was only slightly effective in attenuating the aversive properties of a higher dose of methamphetamine (10 mg/kg) and failed to attenuate the aversive properties of a number of other drugs (p-chloramphetamine at 5.0 mg/kg, fenfluramine at 5.0 mg/kg and morphine at 20 mg/kg). Interpretations of these data are considered and it is suggested that the most parsimonious explanation of the effectiveness of chronic drug pretreatment in attenuating the aversive properties of a drug is that the effect is due to the development of tolerance to the drug administered.     

The role of copper in preventing gastrointestinal damage by acidic anti-inflammatory drugs.

The ability of several non-steroidal acidic anti-inflammatory drugs to cause ulceration when given as copper complexes has been examined. The damage caused by clopirac, niflumic acid and aspirin was virtually abolished when they were given as copper complexes whereas the damage caused by indomethacin, ketoprofen and (+)-naproxen was unaltered. The lack of ulceration with three of these preparations appeared to be correlated with a much reduced ability to inhibit prostaglandin synthesis as determined using an in vitro enzyme system.     

Serotonin receptor blockade potentiates behavioural effects of beta-phenylethylamine

The 5-hydroxytryptamine (5HT) receptor blocker, methysergide (10 mg/kg), was found to potentiate the behavioural effects of β-phenylethylamine (PEA) (at doses between 20 and 60 mg/kg) on food reinforced schedule-maintained behaviour in two separate experiments involving a fixed interval 2 min schedule and a fixed ratio 20 schedule. Potentiation caused a parallel shift to the left in the log dose/response curve for suppression of responding induced by phenylethylamine, and was observed in both male and female rats. These data contrast with recent reports indicating that inhibition of functioning of 5HT systems blocks the effects of phenylethylamine in inducing the “Serotonin behavioural syndrome” (Sloviter et al., 1980a; Dourish, 1981). However, the potentiation reported here is compatible with frequent reports indicating that behavioural effects of amphetamine (-methyl-PEA) can be potentiated by reduction in 5HT functioning and are thus compatible with the hypothesis that phenylethylamine is a potential “endogenous amphetamine”.