Hyperbaric bupivacaine for spinal anesthesia in cesarean section

The efficacy and safety of 0.5% hyperbaric bupivacaine (Sensorcaine, Astra) was evaluated in 22 patients undergoing elective cesarean section under spinal anesthesia. The dose varied from 7.5 to 10 mg, (depending on the patient's height) which was significantly lower than previously reported. Patients were placed in head-down tilt immediately after subarachnoid injection. The mean spread of analgesia was to T3, which was reached in 10-15 min. Regression was complete in 258 +/- 16 min. Complete motor paralysis of lower extremities occurred in only two patients. Complete recovery of motor function in all patients was evident in less than 2.5 h. All infants were vigorous at birth and there were no serious maternal complications. The incidence of hypotension was 4.5%, the lowest reported as a consequence of spinal anesthesia in this group of patients. A technique involving the use of reduced doses of hyperbaric bupivacaine (0.5%) in conjunction with head-down tilt appears to be useful for spinal anesthesia for cesarean section.

The detection of a platelet-agglutinating factor in thrombotic thrombocytopenic purpura

A sensitive and specific test was used to identify a platelet-agglutinating factor in sera from patients with thrombotic thrombocytopenic purpura. Serum from patients plus a preparation rich in large multimers of factor VIII: von Willebrand factor were added to target platelets, and agglutination occurred in 41 of 48 samples. Edetic acid, heparin, or heating, but not aspirin, monomeric IgG, or dansylarginine N-(3-ethyl-1,5-pentanediyl)amide inhibited the platelet-agglutinating factor. In-vitro agglutination requires the presence of a platelet-agglutinating factor and large multimers of von Willebrand factor. High concentrations of either component lowers the amount of the other required for platelet agglutination. Some patients may be more susceptible to the agglutinating factor because of a congenital or acquired abnormality in processing unusually large multimers of von Willebrand factor or because of infections or inflammatory disorders that lead to increased synthesis of large multimers of von Willebrand factor.

Prenatal intramedullary gliofibroma. A light and electron microscope study

A case of an unusual congenital intramedullary tumor of the spinal cord is reported. A paraplegic 11-day-old boy with hypotonia and atrophy of the abdominal and lower-extremity muscles showed a complete myelographic block between T-5 and T-8. Surgical exploration disclosed an elongated tumor mass within the spinal cord, that blended with the surrounding nervous-system tissue. Light and electron microscopy showed that the tumor was composed of intermingled well differentiated astrocytes and fibroblasts. These two cell types often were surrounded by the same basal lamina. There were no intercellular junctions. Gliofibrils were abundant, and the interstitial spaces contained abundant collagen and reticulin fibers. There were no histological signs of malignancy. We conclude that this is a case of prenatally arising gliofibroma.

Regulatory effect of glucagon on its own receptor concentrations and target-cell sensitivity in the rat

To evaluate the role of glucagon on its hepatocyte receptor concentrations, groups of rats were injected with a long-acting glucagon preparation (20 [G-20], 40 [G-40] or 60 [G-60] micrograms/100 g body weight) every 8 h for 4 days. Glucagon receptors in liver plasma membranes of treated animals were decreased in number (control = 1.66 +/- 0.20 ng/0.5 mg protein versus G-20 = 1.24 +/- 0.26, G-40 = 1.03 +/- 0.26, G-60 = 0.70 +/- 0.03 ng/0.5 mg protein; p less than 0.05, less than 0.001, less than 0.001, respectively), but they were indistinguishable from receptors of control rats by other criteria including affinity and kinetics of association. Degradation of both glucagon and receptor sites did not account for differences observed in binding. Similar results were obtained with isolated hepatocytes. In relation to controls, isolated hepatocytes of treated rats had a reduced number of receptors (control = 0.70 +/- 0.05 versus G-40 = 0.47 +/- 0.04 ng/10(6) cells; p less than 0.02) proportionate to the decreased glucagon-stimulated production of cyclic AMP and glucose. Four to eight hours exposure of cultured hepatocytes of nontreated rats to 4 x 10(-8) mol/l glucagon produced a decreased binding of 125I-glucagon to its receptor (p less than 0.05). In contrast, hormone exposure for shorter periods of time (0-2 h) was without effect. These results suggest (1) an inverse relationship between circulating glucagon levels and hepatocyte glucagon receptor concentration, and (2) a direct relation between receptor number and target-cell response.

Sex related differences in platelet function: the effect of aspirin

There is evidence from clinical studies and animal experiments that aspirin has a greater antithrombotic activity in males compared to females. We investigated platelet function in vitro and in vivo in rabbits before and after the administration of a dose of aspirin (5 mg/kg) which inhibited collagen stimulated thromboxane B2 generation. Infusion of collagen into untreated animals resulted in a 38 +/- 4% (m +/- SE, n = 13) decrease in platelet count (assessed by whole blood radioactivity) in the male animals, and a 27 +/- 3% (m +/- SE, n = 13) in the female animals. Pretreatment with aspirin resulted in a significant inhibitory effect in the male but not the female animals (p less than 0.05). The male animals had significantly greater thromboxane B2 generation in vivo than did the female animals following an equal dose of collagen (males, 2.64 +/- 0.7 ng/ml thromboxane B2, n = 14; females, 1.67 +/- 0.4 ng/ml thromboxane B2, n = 15, p less than 0.05). In contrast no sex related difference in the inhibitory effect of aspirin on maximal collagen induced aggregation was found when platelets were studied in vitro. The greater reactivity of male patients in vivo may be accounted for by the observed increase in thromboxane B2 generation. This might also explain the greater thrombotic tendency of males, and the observed difference in the antithrombotic effect of aspirin in males and females.

Synthesis and mode(s) of action of a new series of imide derivatives of 3-nitro-1,8 naphthalic acid

Four new imide derivatives of 3-nitro-1,8-naphthalic acid have been synthesised. The compounds show strong cytostatic activity against both HeLa and KB cells and are moderately toxic towards both mice and rats (LD50 above 4 mg/kg IP). Two of the most active compounds, M-4212 and M-12210, prevented the development of mouse Ehrlich ascites and rat Yoshida carcinoma. All these drugs block cell growth by inhibiting the synthesis of both DNA and RNA. In particular, both M-4212 and M-12210 raise the melting point of double-stranded DNA.

Inhibitors of protein synthesis in eukarytic cells. Comparative effects of some amaryllidaceae alkaloids

The effects of eighteen compounds obtained from bulbs of the Amaryllidaceae family were tested on (a) animal cell growth, (b) DNA, RNA and protein synthesis by intact cells and (c) protein synthesis in cell-free systems. Dihydrolycorine, haemanthamine, lycorine, narciclasine, pretazettine and pseudolycorine halted HeLa cell growth at 10(-1) mM or lower concentrations. These compounds at their growth inhibitory concentrations block protein synthesis in ascites cells and stabilize HeLa cell polysomes in vivo. Endomyocarditis virus RNA-directed cell-free polypeptide synthesis by an ascites S-30 extract and acetyl-[14C]leucyl-puromycin formation by ascites ribosomes are also inhibited by the six compounds indicated above. It is therefore concluded that they halt protein synthesis in eukaryotic cells by inhibiting the peptide bone formation step.

Evaluation of the circumoval precipitin test using dried blood on filter paper as a diagnostic tool in epidemiological survey for schistosomiasis

The suitability of the circumoval precipitin (COP) test in a field survey for schistosomiasis in the rural area using dried blood samples on filter paper was evaluated with reference to the stool examination by the merthiolate-iodine-formaldehyde concentration (MIFC) technique. Both blood and stool samples were collected simultaneously among over 600 inhabitants of two schistosomiasis endemic communities (barrios) of Palo, Leyte, Philippines. The method of collecting blood samples on filter paper, the procedure for COP test and its sensitivity in detecting schistosomiasis cases are described. Blood sampling from finger prick was acceptable to both adults and children so that blood samples were readily obtained while the collection of stool samples required repeated visits to the homes. A significantly higher percentage of schistosomiasis positives were obtained by COP test than by stool examination. The COP test results were comparable to the stool examination results on the following aspects: 1) highest infection rate in the 10-19 age group and lowest infection rate in the 60 years old and above; 2) positive rates for schistosomiasis did not differ significantly between the two barrios and 3) no family accumulation of the disease in the two communities was observed in this survey in 1972. The stability of the antibody in filter paper, the reliability of the test and the simple and rapid procedures involved make this filter paper method of COP test very practical and suitable for schistosomiasis survey in rural areas.