Insect sting anaphylaxis; prospective evaluation of treatment with intravenous adrenaline and volume resuscitation.

OBJECTIVES: To assess a protocol for treatment of sting anaphylaxis. DESIGN: Prospective assessment of treatment with oxygen, intravenous infusion of adrenaline (epinephrine), and volume resuscitation with normal saline. SETTING: Sub-study of a venom immunotherapy trial. PARTICIPANTS: 21 otherwise healthy adults with systemic allergic reactions to diagnostic sting challenge. MAIN OUTCOME MEASURES: Response to treatment, total adrenaline dose and infusion duration, recurrence of symptoms after stopping the infusion, and additional volume resuscitation. RESULTS: 19 participants required intervention according to the protocol. All received adrenaline, and five received volume resuscitation. In nine cases, physical signs of anaphylaxis recurred after initial attempts at stopping adrenaline but resolved after recommencing the infusion. The median total dose and infusion duration were 590 micro g and 115 minutes respectively, but were significantly higher for eight patients who had hypotensive reactions (762 micro g and 169 minutes respectively). Hypotension was always accompanied by a relative bradycardia, which was severe and treated with atropine in two patients. Widespread T wave inversion occurred, before starting treatment with adrenaline, in one person with an otherwise mild reaction. All patients fully recovered and were fit for same day discharge, apart from the person with ECG changes who was observed overnight and discharged the following day. CONCLUSIONS: Carefully titrated intravenous adrenaline combined with volume resuscitation is an effective strategy for treating sting anaphylaxis, however severe bradycardia may benefit from additional treatment with atropine. Cardiac effects of anaphylaxis, perhaps including neurocardiogenic mechanisms, may be an important factor in some lethal reactions.

Culture media for propagation of mammalian cells, viruses, and other biologicals.

In this brief review, we have illustrated the historical development of the growth media commonly employed for the propagation of cultured mammalian cells. While substantial progress has been achieved, the field may best be described as conservative and pragmatic. To date, the function of many components of the growth medium essential for cellular proliferation and biological production has not been precisely defined at the molecular level. Thus, for most large-scale biological production requirements, as well as for routine cell culture and bench-scale pilot development, the traditional enriched culture medium supplemented with fetal bovine serum represents the most convenient culture system. Many cell types may be more economically grown without reduction in biological yield by substituting alternative mammalian sera. Where reduction of total protein or greater definition of growth medium components outweighs the use of more universally applicable culture media, substitution of serum-free, customized formulations of highly enriched growth medium plus defined growth factors may be of significant utility. Optimization of mammalian cell culture media for large-scale biological production should include the following: An initial time investment to optimize the cell culture medium by enriching intermediary metabolite composition (rather than expecting serum or additional growth factors to perform nutritional functions) may result in higher productivity and reduced cost. When screening potential growth media for biological production applications, proliferative rate should not be the sole criterion for performance. Although rapid, logarithmic growth is advantageous to establish large-scale cultures, the maximal cell density and duration of the viable, productive period must also be weighed. Many cell types generate the highest titers of biological product either at stationary phase or under mildly stressful ("controlled death") conditions suboptimal for cellular replication. Thus, the ultimate determinant of growth medium efficacy is neither the degree of definition of medium composition nor the cellular proliferative rate, but the ability to support synthesis of substantial titers of the desired product at reasonably high purity.

Carcinogenic effects of combined treatment of inbred mice with 3-methylcholanthrene and 1,2-dimethylhydrazine.

Inbred mice of strains C57BL/6J (B6) (Ahb/-Ahb) and DBA/2J (D2) (Ahd/Ahd) were administered 3-methylcholanthrene (MCA) alone, 1,2-dimethylhydrazine (DMH) alone, and MCA and DMH together. Colorectal tumors were observed in 32% of the DMH-treated B6 mice, but no such tumors occurred in similarly treated D2 mice. Of the MCA-treated D2 mice, 46% were susceptible to leukemia, whereas in similarly treated B6 mice, 19% developed only lung tumors. The combined application of MCA and DMH resulted in an increased incidence of colorectal (52%) and lung (44%) tumors in B6 mice and, to some extent, of leukemia (63%) in D2 mice. The role of genetic background on the carcinogenic effects of combined application of MCA and DMH in inbred mice is discussed.

Differential susceptibility of 3 sublines of C57BL/6 mice to the induction of colorectal tumors by 1,2-dimethylhydrazine.

Eight-week-old mice of 3 sublines of strain C57BL/6 were given s.c. injections of 1,2-dimethylhydrazine (DMH), once weekly for 10 weeks. The highest incidence (85%) of colorectal tumors occurred in C57BL/6N mice. Colorectal tumors occurred in 43% of C57BL/6J mice, while only 3 (10%) C57BL/6Ha mice developed these tumors. Possible factors responsible for the differential susceptibility of 3 sublines of C57BL/6 mice to the induction of colorectal tumors by DMH are discussed.

Cell surface alterations induced by vaccinia and Newcastle disease viruses (38486).

A comparison was made of HEp-2 cell surface changes induced by NDV or vaccinia virus infection. Three parameters were examined as a function of time after infection: the kinetics of hemadosorption and the appearance of concanavalin (con A) binding sites, and alterations in electrophoretic mobility of single cells. The kinetics of appearance of con A binding sites was strikingly similar for both virus infections, whereas hemadsorption preceded NDA synthesis and followed vaccinia synthesis. These data suggest that in the vaccinia-infected cell the hemadsorption and con A binding sites are different. NDV infection or exposure of sham-infected cells to bacterial neuraminidase significantly reduced their anodal mobilities. This also occurred after enzyme treatment of vaccinia-infected cells. Measurements of the sialic acid content of NDV or sham-infected cells before and after neuraminidase treatment indicated the exposure to the enzyme or NDV materially reduced the sialic acid content of cells. Vaccinia-infected cells contained considerably more sialic acid than did normal cells. For the vaccinia-infected cell a change in surface properties as detected by hemadsorption or increased con A binding was not reflected in a change in electrophoretic mobility.

Origin of the vaccinia virus hemagglutinin.

The relationship between the vaccinia virus hemagglutinin and hemadsorption was examined. Hemagglutinin synthesis was temporally related to the appearance of the hemadsorption reaction. Only chicken erythrocytes, which reacted with hemagglutinin, hemadsorbed to infected cells, and both of these reactions were inhibited by Ca(2+). The distribution of the vaccinia hemagglutinin and 5'-adenosine monophosphatase, a plasma membrane marker enzyme, in sucrose gradients was similar. Plasma membrane ghosts derived from infected cells hemadsorbed erythrocytes and yielded hemagglutinin upon sonic disruption. These data suggest that the majority of vaccinia hemagglutinin is derived from the plasma-membrane of the infected cell.

Poliovirus-induced Cellular Injury.

Protein leakage was used as a quantitative measure of poliovirus-induced cellular injury under suspended cell culture conditions. The requirements for protein leakage were studied in detail and it was established that events early in the infectious cycle which depend upon viral protein synthesis were responsible for cell damage. Extralysosomal beta-glucuronidase appeared in infected cells before the onset of protein leakage and release of newly synthesized virus. Hydrocortisone treatment of infected cells resulted in only a slight delay in the release of beta-glucuronidase from lysosomes and protein and virus from cells. These results suggest that events associated with poliovirus synthesis trigger the release of lysosomal hydrolases which in turn injure the plasma membrane, allowing cytoplasmic proteins and virus to leak out of the cell.