Molecular mechanisms and regulation of insulin exocytosis as a paradigm of endocrine secretion

Secretion of the peptide hormone insulin from pancreatic beta cells constitutes an important step in the regulation of body homeostasis. Insulin is stored in large dense core vesicles and released by exocytosis, a multistage process involving transport of vesicles to the plasma membrane, their docking, priming and finally their fusion with the plasma membrane. Some of the protein components necessary for this process have been identified in beta cells. The export of potent and potentially harmful substances has to be tightly controlled. The secretory response in pancreatic beta cells requires the concerted action of nutrients together with enteric hormones and neurotransmitters acting on G-protein coupled receptors. It is well established that glucose and other metabolizable nutrients depolarize the beta-cell membrane and the ensuing Ca2+ influx through voltage-dependent channels constitutes a main stimulus for insulin exocytosis. Theoretical considerations and recent observations suggest in addition an organizing role for the Ca2+ channel similar to neurotransmission. A second regulatory control on exocytosis is exerted by monomeric and heterotrimeric G-proteins. The monomeric GTPase Rab3A controls insulin secretion through cycling between a guanosine triphosphate liganded vesicle-bound form and a guanosine diphosphate liganded, cytosolic form. The effect of neurohormones is transduced by the heterotrimeric GTPases. Whereas pertussis-toxin sensitive alpha-subunits exert direct inhibition at the level of exocytosis, the Gbeta gamma-subunits are required for stimulation. It is possible that these GTPases exert immediate regulation, while protein kinases and phosphatases may modulate long-term adaptation at the exocytotic machinery itself. The molecular nature of their activators and effectors still await identification. Insights into the progression of the exocytotic vesicle from docking to fusion and how these processes are precisely regulated by proteins and second messengers may provide the basis for new therapeutic principles.

Development of orphan vaccines: an industry perspective

The development of vaccines against rare emerging infectious diseases is hampered by many disincentives. In the face of growing in-house expenditures associated with research and development projects in a complex legal and regulatory environment, most pharmaceutical companies prioritize their projects and streamline their product portfolio. Nevertheless, for humanitarian reasons, there is a need to develop niche vaccines for rare diseases not preventable or curable by other means. The U.S. Orphan Drug Act of 1983 and a similar proposal from the European Commission (currently under legislative approval) provide financial and practical incentives for the research and development of drugs to treat rare diseases. In addition, updated epidemiologic information from experts in the field of emerging diseases; increased disease awareness among health professionals, patients, and the general public; a list of priority vaccines; emergence of a dedicated organization with strong leadership; and the long-term pharmacoeconomic viability of orphan products will be key factors in overcoming the complexity of orphan status and the limited need for vaccine.

[Recurrent epithelial ovarian cancer]

OBJECTIVE

To evaluate the factors of influence on recurrent epithelial ovarian cancer and to make strategy of treatment.

METHODS

Retrospective study of 189 cases of ovarian cancer admitted in our hospital from Jan, 1987 to Dec, 1997. All of these cases had postoperative pathological diagnosis.

RESULTS

Of 31 recurrent cases, 19 cases had first cytoreductive surgery in our hospital, while other 12 cases were done in other hospitals. According to FIGO criteria, stage I, II 4 cases (12.9%), III, IV 27 cases (87.1%). The mean recurrent time of no-residual disease was 17.2 months, while that of residual disease < or = 2 cm was 10.1 months (P < 0.01). The mean recurrent time of those having chemotherapy > or = 6 cycles was 13.1 months, while that of those having chemotherapy < 6 cycles was 10.1 months (P > 0.05). The five-year survival rate of 18 cases having secondary cytoreductive surgery was 27.3%, while that of 4 cases having chemotherapy only was 7.1% (P < 0.01). The five-year survival rate of 7 cases abandoning any therapy was 4.8% (P < 0.01). 2 cases had only irradiation therapy.

CONCLUSIONS

Histology, stage, degree of tumor differentiation, chemotherapy and the residual disease of cytoreductive surgery all influence recurrence of epithelial ovarian cancer. Secondary cytoreductive surgery along with chemotherapy can raise recurrent epithelial ovarian cancer's five-year survival rate.

Dynamic cardiomyoplasty in patients with end-stage heart failure: anaesthetic considerations

Dynamic cardiomyoplasty is used increasingly for patients with chronic heart failure, with approximately 500 cases having been performed. The latissimus dorsi muscle is prepared maintaining its vascular supply and the muscle flap is wrapped around the heart and connected to a cardiomyostimulator. The muscle is later stimulated synchronously with ventricular systole to augment the heart. Our experience of 22 patients with chronic heart failure (NYHA III-IV) undergoing dynamic cardiomyoplasty is described from the anaesthetist's point of view. Two patients are reported as case reports. The challenge is to manage patients with severely impaired left ventricular function, who do not obtain immediate benefit from the operation. Our experience supports the importance of early use of inotropic agents.

The immunogenicity and safety of a new combined diphtheria, tetanus and poliomyelitis booster vaccine (Td-eIPV)

In view of the continuing risk of contracting tetanus, diphtheria and poliomyelitis, and the well-documented decline in immunity with time, the need for booster vaccinations is substantial. The immunogenicity and safety of a new combined booster vaccine against tetanus, diphtheria and poliomyelitis (REVAXIS) developed by Pasteur Mérieux Connaught (Lyon, France) were evaluated in four clinical studies. This vaccine (Td-eIPV) combines an adsorbed tetanus toxoid and low-dose diphtheria toxoid vaccine (Td) with an enhanced, inactivated polio vaccine against poliovirus types 1, 2 and 3 (eIPV). In 256 healthy young adults, a single dose of Td-eIPV was shown to be immunogenic, eliciting antibody levels considered protective against disease for each vaccine component in > or = 99.6% of the subjects. In 112 healthy older subjects (> 40 years of age), two doses of Td-eIPV elicited seroprotective levels of antibodies in 94% of the subjects for diphtheria, and in all subjects for tetanus and poliovirus types 1, 2 and 3. Safety data from all 368 subjects, as well as 31 phase I volunteers and 1,742 subjects included in a safety study, reveal that the vaccine is safe. Most reactions were predictable, temporary and mild. There was no evidence that the vaccine was associated with any clinically serious event or modification of clinical laboratory parameters. The data reviewed here show that Td-eIPV is immunogenic and safe when administered as a booster vaccination in healthy adults of all ages.

[Clinical observation of conservative surgery for adenomyosis]

OBJECTIVE

To study the clinical value of conservative surgery for adenomyosis in reducing symptoms and raising pregnancy rate.

METHODS

26 women with histologically proven adenomyosis who wanted to preserve their reproductive capacity had conservative surgery (adenomyomectomy or remove part lesion). The patient's average age was 35.8 years. The main complaints were dysmenorrhea and hypermenorrhea. Of the 22 married patients, 7 had primary infertility (31.8%), 10 had secondary infertility (45.5%) and 3 had habitual abortion (13.6%).

RESULTS

10 patients had adenomyoma, the lesion were completely removed. Sixteen patients had adenomyosis, the part of lesion were removed. The rate of the severe dysmenorrhea and hypermenorrhea after operation were significantly lower than that before (P < 0.001). After operation, 7 patients with adenomyoma wanted to have a baby, 5 patients conceived, of the total 9 pregnancies, 5 ended in term pregnancy; 14 patients with diffuse adenomyosis wanted to have a baby, 3 patients had 3 pregnancies. One of which ended in term pregnancy. The rate of pregnancy and term delivery in adenomyoma patients were significantly higher than that of adenomyosis patients (P = 0.03, P = 0.002). Among 26 patients, 3 relapsed. The average relapse time was 49.6 months.

CONCLUSIONS

The conservative surgery for adenomyoma can reduce symptom and raise pregnancy rate significantly, it can be accepted by young women who want to preserve their reproductive capacity. Though the pregnancy rate of conservative surgery for diffused adenomyosis was low, it still has therapeutic value.

Immunogenicity and safety in adults of a new chromatographically purified Vero-cell rabies vaccine (CPRV): a randomized, double-blind trial with purified Vero-cell rabies vaccine (PVRV)

Recent improvements in chromatographic purification procedures have made it possible to develop a new chromatographically purified rabies vaccine (CPRV) by further purifying the current rabies vaccine prepared from Vero-cell culture (Verorab; Pasteur Mérieux Connaught). The immunogenicity and safety of primary immunization, followed by a booster at one year, with CPRV was compared to that of the purified Vero cell vaccine (PVRV) in a randomized, double-blind study carried out at four veterinary schools in France. A total of 330 healthy, male and female, first-year veterinary students, aged at least 18 years and who required pre-exposure rabies prophylaxis, were enrolled in this study. Included subjects were randomly assigned either CPRV (n = 163) or PVRV (n = 167) to be given as a primary immunization series of three intramuscular injections (D0, D7, D28), followed by a booster after 1 year (D365). Blood samples for serological analysis were taken at D0 (before first injection), D28, D42, D180, D365 (before booster) and D379. All subjects developed a strong immune response to the primary series, and at D42, all subjects had seroconverted for rabies neutralizing antibody (serum titre > or = 0.5 IU/ml). The rabies virus-neutralizing antibody GMT value at D42 in the CPRV group (23.0 IU/ml) was non-inferior to that in the PVRV group (29.6 IU/ml), according to a one-sided non-inferiority test. While antibody titres tended to decrease over the period of follow-up, at D365 (before booster), 97.5% subjects in the CPRV group and 98.8% of subjects in the PVRV group remained seroconverted. After booster, although the rabies antibody GMT value in the CPRV group was lower than that in the PVRV group, all subjects in both groups were seroconverted, and the difference is probably not clinically important. The incidence of local and systemic reactions tended to decrease with each dose during the primary immunization series, followed by a slight increase after booster (significant time-effect in an exploratory logistic regression analysis). Although mild or moderate local reactions tended to be more frequent after injection with CPRV compared to PVRV, systemic reactions were reported less often (significant group-effects in exploratory logistic regression analyses). One serious adverse event possibly related to vaccine occurred during this study (severe asthenia after the third dose of PVRV). This comparative study in healthy young adults demonstrates that the new chromatographically purified rabies vaccine is as immunogenic as PVRV, and seems to be associated with fewer systemic reactions.

[Comparative study on effect of Panax notoginseng and ticlid in treating early diabetic nephropathy]

OBJECTIVE

To explore the ameliorative effect and mechanism of Panax notoginseng (PNG) and ticlid in treating early diabetic nephropathy (DN).

METHODS

Fifty-eight patients were divided randomly into two groups, 28 patients of the ticlid group treated with ticlid 250 mg orally, once a day and 30 patients of the PNG group treated with PNG 8 ml in 250 ml of normal saline intravenous drip once a day. The therapeutic effect and relative indexes of the two groups were observed and compared.

RESULTS

After treatment, in both groups, the thromboxane B2 markedly reduced and was more prominent in the ticlid group (P < 0.05), while the 6-keto-prostaglandin F1 alpha increased obviously, so as to cause a significant lowering of T/K ratio, P < 0.01. Levels of urinary albumin, beta 2 microglobulin and blood alpha 1 microglobulin of both groups were lowered significantly, P < 0.01. A significant positive linear correlation was found in the ticlid group between urinary albumin and T/K ratio (r = 0.41, P < 0.01), as well as in blood alpha 1 microglobulin with T/K ratio (r = 0.34, P < 0.05), while it was not found in the PNG group.

CONCLUSION

Ticlid and PNG were beneficial to resume the balance of T/K and improve microcirculation, reduce whole blood viscosity and decrease urinary albumin so as to retard the progress of DN.

Persistence of antibodies in children after intradermal or intramuscular administration of preexposure primary and booster immunizations with purified Vero cell rabies vaccine

BACKGROUND

The use of intradermal (i.d.) injections of purified Vero cell rabies vaccine (PVRV) for preexposure prophylaxis has not been well-established. We studied the safety and immunogenicity of i.d. and intramuscular (i.m.) PVRV injections for primary and booster preexposure immunizations.

METHODS

One of two rabies preexposure PVRV regimens comprising three doses of either 0.1 ml i.d. or 0.5 ml i.m. administered during 28 days was assigned at random to 190 school children. One booster dose was given 1 year later either i.d. or i.m., according to their initial randomization group. Serologic results were available from 155 (82%) children at 1 year after primary immunization and 118 (62%) children at 2 years after booster.

RESULTS

Although children vaccinated i.d. had significantly lower rabies-neutralizing antibody titers after primary immunization as well as after booster than children vaccinated i.m. (P< 0.001 for all time points), there were no significant differences in the percentages of children with adequate titers (> or =0.15 IU/ml) between the i.d. and i.m. groups after both primary and booster immunizations. Mild local reactions were more frequent after i.d. vaccination. Mild or moderate systemic reactions were infrequent and similar after i.d. and i.m. vaccinations. Fever and headache were reported by < or =6%. The reactions after booster were not different from those of post-primary immunization.

CONCLUSIONS

Purified Vero cell rabies vaccine appears to be safe and immunogenic for primary and booster preexposure immunizations. An i.d. PVRV preexposure regimen should be useful especially for rabies-endemic countries with low per capita income.

[A computerized information system for gynecological patients]

OBJECTIVE

Clinical experiences in the fields of general gynecology, gynecological oncology and reproductive endocrinology had been accumulated over a long period of time. All of the recorded information was written on various kinds of sheets that could easily be damaged and lost with frequent reading. Statistical works were done manually. This is the situation may encountered by all of the hospitals in China, so a computerized information system for gynecological patients is eagerly needed.

METHODS

The program was designed on the basis of Foxpro 2.6 for Windows.

RESULTS

The interfaces were specially designed for every of 72 databases to be like the style of patient's records which can be easily operated with mouse pressing buttons. Some of the databases such as basal body temperature, metastasis of lymph nodes and classification of endometriosis were carefully designed. Because the program will be used in China, the interfaces were all in Chinese. A dictionary was used to simplify the importing of the data. When import, one can easily press the line with the appropriate meaning in the dictionary. A strong statistical function was attached to the program. With its friendly interface, statistical work can be done with ease. This system is capable of further development and fit into needs of various hospitals and departments.

CONCLUSION

This program is very useful for clinical doctors as well as scientific research personnel. With the help of this program, efficacy of our medical work can be raised, clinical experiences can be summarized in time and the clinical level can thus be improved.

Clinical safety of a polyvalent F(ab')2 equine antivenom in 223 African snake envenomations: a field trial in Cameroon. VAO (Venin Afrique de l'Ouest) Investigators

A large-scale clinical trials was conducted, according to World Health Organization Good Clinical Practice guidelines, in 7 centres in north Cameroon to determine the safety and efficacy of a polyvalent antivenom composed of purified F(ab')2. This study included 223 patients presenting clinically with obvious snake bite, predominantly due to Echis ocellatus (viper), the most abundant species in this savannah region. Clinical surveillance was maintained for 5 d in all patients and until the twenty-sixth day in 74% of cases. Two 10 mL ampoules of polyvalent F(ab')2 equine antivenom (Ipser Africa) were administered to each patient by intravenous infusion. If necessary, treatment was repeated 1 h after the end of the first infusion, and then with a frequency determined by the patient's clinical condition. Before initiation of antivenom treatment, the main clinical disorders observed on admission were oedema (93.7%) and haemorrhage (48.9%), with a clotting time longer than 30 min in 65.4% of patients. Clinical cure was obtained in 213 patients (96.8%). No amputation was necessary, and the case fatality rate was only 1.3%. On average, 4.6 (+/- 3.7) ampoules were administered per patient; 43% of subjects recovered after only a single infusion of 2 ampoules. Early adverse reactions, of varying degrees of severity, were observed in 6.3% of patients. A severe early reaction, anaphylactic shock, was observed in only one patient (0.4%). Serum sickness was observed in another patient. Polyvalent F(ab')2 equine antivenom given by repeated 20 mL intravenous infusions is a safe and effective treatment for envenomation caused by African vipers.

Cysteine-string proteins regulate exocytosis of insulin independent from transmembrane ion fluxes

Cysteine-string proteins (Csps) are vesicle proteins involved in exocytosis of synaptic vesicles in Drosophila and modulation of presynaptic calcium influx. As both the contribution of calcium channel regulation to the role of Csp in exocytosis and a function of Csp outside the nervous system are unknown, we studied its function in endocrine exocytosis from large dense core vesicles (LDCVs) using insulin-secreting pancreatic beta-cells. Csps were expressed in primary and derived beta-cell lines on insulin-containing LDCVs. Suppression of Csp expression reduced not only depolarisation induced insulin release but also exocytosis in permeabilised cells directly stimulated by Ca2+. Thus, Csp is a secretory granule protein and is required for endocrine exocytosis independent of the modulation of transmembrane calcium fluxes.

[Epidemiologic and genetic studies of canine hip dysplasia in a population of Labrador retrievers: a study over 25 years]

The occurrence of canine hip dysplasia (CHD) was analyzed in a colony of 738 Labrador Retrievers between 1972 and 1996. Of these dogs, 86.3% were radiographically examined for hip dysplasia. The overall prevalence of CHD was 31.3% during the study period of 25 years. Between 1972 and 1980, the prevalence of CHD was 57.9%. It decreased to 14.9% between 1991 and 1996. Univariate and multivariate logistic regression models were developed to identify the influence of potential risk factors for CHD such as age at examination, gender, color, year and season of birth, litter size, order of birth, birth weight, body weight and daily weight gain. Birth year and age at examination proved to be significant risk factors. No significant association was found between CHD and elbow dysplasia. Of the dogs diagnosed with CHD, 18% showed dysplastic changes only, without radiographic signs of secondary osteoarthritis (OA). The Norberg angle (NA) proved to be a significant risk factor for coxofemoral osteoarthritis with a moderate negative correlation between OA and NA. Finally, genetic effects were calculated in a mixed model. Heritability (h2) of CHD was estimated at 0.53 (SE = 0.17) for paternal half siblings. The proportion of the common environment of a litter to the total variance was estimated at C2 = 0.03.

Safety and efficacy of purified Vero cell rabies vaccine given intramuscularly and intradermally. (Results of a prospective randomized trial)

OBJECTIVES

To determine adverse reactions as a result of pre- and post-exposure rabies vaccination, using the conventional intramuscular, and reduced dose intradermal regimens and purified Vero cell rabies vaccine.

DESIGN

A prospective and randomized study of patients exposed to rabies and of subjects in need of pre-exposure rabies vaccination.

SETTING

A metropolitan rabies control center in a canine rabies endemic country.

PATIENTS

1198 subjects were recruited between May, 1994 and March, 1996. They were divided into four groups. Patients with suspected or proven rabies exposures were given the vaccine intramuscularly using the conventional regimen, or intradermally using the World Health Organization approved Thai Red Cross schedule. Human or equine rabies immune globulin was administered where indicated. Pre-exposure and post-exposure vaccine recipients were divided randomly into two groups each and given the vaccine either by the intramuscular or intradermal schedules.

MEASUREMENTS

All local and systemic adverse reactions were recorded and statistically analyzed.

RESULTS

Pruritus at injection sites was the only significant local reaction. It was more common in the intradermal groups. Low-grade fever, the only significant adverse systemic event, was more common in the intramuscular groups and was noted in 8% of all subjects. Eighty-four patients bitten by proven rabid animals were found to be alive and well 3 years later. Forty-four of these had received the intramuscular and 40 the intradermal postexposure regimens with human or equine immune globulin injected into wounds on the first day of treatment.

CONCLUSIONS

Purified Vero cell rabies vaccine is safe, carries a very low adverse reaction rate and is effective in preventing rabies in severely exposed subjects when used with human or equine rabies immune globulin.

[Interleukin 2 gene transfer on the proliferation and morphology of ovarian cancer cell line SKOV3]

OBJECTIVE

To study the effect of interleukin-2 (IL-2) gene transfer on the proliferation and morphology of ovarian cancer cell line SKOV3.

METHOD

IL-2 gene was introduced into ovarian cancer cell line SKOV3. The morphologic changes, mitosis, proliferation curve, 3H-uptaking and cell cycle were studied.

RESULTS

IL-2 cDNA, 490 bp, was transduced. IL-2 gene expression was detected. IL-2 activity was 30-318 U/10(6) cells/24hr. IL-2 gene modified cell is squamas like with smaller nucleus/cytoplasm ratio, larger cell area and more homogeneous. The ultrastructural study showed that the cytoplasma of IL-2 gene modified cells is markedly vacuolized and the chromatin is condensed. There was less mitosis found in SKOV3/IL-2 cells. SKOV3/IL-2 cell proliferate more slowly, the doubling time prolonged from 38.40 hr to 65.36 hr, 3H-uptaking decreased 52.3% of the parent cell. The cell cycle study showed that SKOV3/IL-2 cell was blocked to phase G1/G0.

CONCLUSIONS

The retrovirous vector can transduce Il-2 gene into ovarian cancer cell line SKOV3 effectly. IL-2 gene transfer can induce morphologic changes of SKOV3 cells, which may indicate the biologic behavior changes of the targets. IL-2 gene transfer can induce the proliferation inhibition of SKOV3 cells.

[The comparison of biological characteristics between tumor-infiltrating lymphocytes and tumor-associated lymphocytes in ascites of epithelial ovarian carcinoma]

OBJECTIVE

To compare biological charicteristics between tumor-infiltrating lymphocytes (TIL) and tumor-associated lymphocytes (TAL) in epithelial ovarian carcinomas.

METHODS

The surgical samples of four ovarian specimens and eight cancer ascites from epithelial ovarian carcinoma were collected, and ascites were divided into bloody and non-bloody groups. The cancer tissue was dissected to yield single cells suspensions. TIL and TAL were grown in coculture with autologous tumor cells and 500 U/ml recombinant interleukin-2 (rIL-2). Phenotype was studied using flow cytometry for a varity of human immunocompetent cell surface markers (CD3, CD4, CD8, CD25). Cytotoxicity was investigated using 4-hr 51Cr-release assays with primary ovarian carcinoma cell cultures and the CAOV3 cell line and the K562 cell line as target cells in cultured period.

RESULTS

(1) There was no significant difference in CD3, CD4, CD8 and CD25 expression among the three groups (P > 0.05). CD4 to CD8 (CD4/CD8) ratio was consistently more than 1 in cultured period. (2) In all three groups, Natural killer (NK) acitivity was high and no difference among them (P > 0.05). (3) In all twelve cases, TIL and TAL in the non-bloody ascites possess higher potential to lyse the autologous tumor target than TAL in the bloody ascites (P < 0.01) when effector cell to target cell (E:T) was 50 to 1 (50:1). Lytic activity was 30.2%-51.0% and 10.8%-15.8% respectively.

CONCLUSIONS

TIL and TAL in non-bloody ascites in epithelial ovarian cancer have the same biological characteristics.

[Application of coronal CT scan and three-dimensional reconstruction in rhinology]

To display the structure of the Ostiomeatal Complex (OMC) more clearly, and provide clearer and more living imaging for safe functional endoscopic sinus operation and thoroughly eliminating the focus of disease, coronal CT scanning and 3-dimensional reconstruction were performed in 168 sinusitis patients (290 sides) and 107 patients with sinusitis and nasal polyposis (175 sides). The CT findings were compared with endoscopic examination and normal people were taken as control. The found of coronal CT and endoscopic examination are consistent in recognizing mucosal thickening within nasal cavity and sinuses. Three-dimensional CT is more living than common coronal CT in displaying the uncinate process and turbinates. Our conclusion is that coronal CT scan processes high values for recognizing nasal sinus disease, anatomical variants, disease extent and adjacent structures of OMC. Three-dimensional reconstructed CT make the image of OMC more stereoscopic, audio-visual and living.

[Snake bite by European vipers. A multicenter study of tolerance to Viperfav, a new intravenous antivenom]

OBJECTIVES

To evaluate the tolerance and the effectiveness of i.v. Viperfav, a new antivenom containing F(ab')2 fragments of equine antibodies, for the treatment of European viper envenomed patients.

STUDY DESIGN

Open, multicentre field trial, associated with a cohort study.

PATIENTS

The study included 46 patients of either gender, nine aged less then 10 years, eight between 10 and 15 years, and 28 adults, who sustained a moderate or severe viper envenomation (Grade 2 or 3).

METHOD

At the inclusion, a single infusion of Viperfav was given. Depending on the clinical course, up to four additional infusions were to have been administered at 4-hour intervals. To evaluate tolerance, all symptoms were recorded. There were three effectiveness evaluation criterion (duration of hospitalisation, course of the severity grade, recovery (sequelae)) and one subjective criteria (value of the antivenom as ascertained by investigators).

RESULTS

In the 46 included patients, 79 infusions were administrated. Concerning tolerance, six mild symptoms were associated to the antivenom infusions. No severe reaction occurred. The mean duration of hospitalisation was 4 days 19 hours +/- 13 hours. A severity grade decrease by at least one point was observed in 35 patients, and all were discharged without sequelae. For the investigators the antivenom was inefficient in only two patients (grade 3 with tissue lesions).

CONCLUSIONS

In comparison with literature data (5 to 10% of severe reactions attributable to the antivenom), the tolerance of Viperfav can be considered as satisfactory. As all criteria were in favour of a positive benefit to risk ratio, the authors recommend the use of Viperfav i.v. for the grade 2 and 3 envenomations instead of the current less purified antivenom, which can only be administered by the intramuscular route.

Optimization of temperature distributions for regional hyperthermia based on a nonlinear heat transfer model

We describe an optimization process specially designed for regional hyperthermia of deep seated tumors in order to achieve desired steady-state temperature distributions. A nonlinear three-dimensional heat-transfer model based on temperature-dependent blood perfusion is applied to predict the temperature. Optimal heating is obtained by minimizing an integral object function which measures the distance between desired and model predicted temperatures. Sequential minima are calculated from successively improved constant-rate perfusion models employing a damped Newton method in an inner iteration. Numerical results for a Sigma 60 applicator are presented.