Cryosurgery of lentigo maligna.

Lentigo maligna denotes flat, pigmented lesions predominantly in areas of actinic damage that have the propensity to become malignant. More than 10 years may pass before lentigo maligna evolves into an invasive neoplasma. As an invasive process, it is termed lentigo maligna melanoma (LMM), and it has the potential for both lymphatic and hematogenic metastases. Because of the size and location of the lesions, cosmetically unsatisfactory scars may result from conventional surgery. Therefore, alternative means of treatment, including cryosurgery, have been employed. We report on 12 patients suffering from lentigo maligna who had been treated successfully by cryosurgery between 1984 and 1990. The average follow-up period was 51.4 months, and the recurrence rate was 8.3 percent. Knowing that microinvasive components can be demonstrated in 15 percent of lentigo maligna lesions, we retrospectively reassessed our patients by immunohistochemical procedures with S-100 protein. Although intradermal microinvasion could be confirmed in one patient, no recurrence had been observed within 61 months of follow-up. Provided that patients are selected properly and extension of cryonecrosis is monitored, cryosurgery may prove an efficient alternative to conventional surgery in the treatment of lentigo maligna.     

Factors affecting population density, group size and territory size of the European badger, Meles meles

This paper discusses the relationship between the distribution and biomass of the main prey of European badgers, Meles meles and the badgers group size, territory size and population density. The distribution of areas rich in earthworms, Lumbricus spp., is correlated with badger range size, whilst badger group size increases with the biomass of worms per badger territory and badger density increases with overall worm biomass. Regulation of badger density in an area is likely to take place through regulation of group size, in the absence of other factors such as persecution and lack of suitable sett-sites.     

Mendelian analysis of the organization of actin sequences in Physarum polycephalum

The genormic organization of the multiple actin DNA sequences in the lower eukaryote Physarum polycephalum was investigated by Mendelian mapping. Actin-homologous restriction endonuclease cleavage fragments detected by DNA blotting showed length polymorphisms when different strains were compared. These length polymorphisms were used as phenotypic markers for actin sequences in the genome. The meiotic assortment of the polymorphic restriction fragments was analysed, revealing four unlinked actin loci. The data for three-of the actin loci, ardB, C and D, are consistent with a single sequence or gene at each locus. The data for the other actin locus. ardA, is consistent with multiple linked actin sequences or genes.     

Cerebral Synaptic Transmission During Anoxia Is Protected by Creatine

Synaptic transmission in cerebral tissue fails very rapidly in the absence of oxygen; the metabolic basis for this is not known. We report here that the transmission failure in the guinea pig hippocampal slice can be delayed threefold by exposing the tissue to extracellular creatine (Cr) for 3 h. The improved survival is associated with an increase of tissue phosphocreatine (PCr) concentration. These data argue that the metabolic basis for synaptic transmission failure is a fall in tissue ATP concentrations. They also indicate a way to protect brain tissue against anoxic damage.     

Effects of energy level and monensin on reproductive performance and lactation of beef cows

This experiment consisted of a 2 year drylot study involving 80 multiparous, suckled beef cows (40 Angus and 40 Herefords). Experimental treatments (breed, monensin and year) were arranged in 2(3) factorial to evaluate the effect of breed and monensin on reproductive performance and lactation. Cows received 85% of the NRC total digestible nutrient (TDN) requirement for the first 56 days of the 140 day trial. Cows were synchronized with Synchro-Mate B and artificially inseminated 30 days into each trial with blood samples collected for luteinizing hormone (LH) analysis from one-half of each treatment group from 24 to 36 hours after implant removal. Progesterone determinations were made on plasma samples collected at day 9 and 16 after implant removal. On day 56, milk yield estimates were obtained by the weigh-suckle-weight technique. Following these collections, energy levels were increased by allowing ad lib consumption of forage. Calves, which were removed from the cows during feeding, were given access to a 75% TDN creep ration after day 56. Milk estimates were again evaluated at 140 days. Monensin supplementation did not result in a difference in cow weight change through the restricted energy period (first 56 days) or throughout the entire 140 day period. Milk yield estimates at 56 and 140 days and calf gains throught the trial, were unaffected by monensin supplementation. Monensin resulted in no effect on conception rate or services per conception. The time of the LH peak was shifted slightly forward by monensin although not significantly. Progesterone levels were not consistently affected by monensin supplementation.     

A haemagglutination inhibition test kit for routine analysis of erythropoietin.

A commercially available haemagglutination inhibition test kit for routine analysis of erythropoietin was shown to be unable to detect elevated levels of serum Epo.     

Correlations between human portal and peripheral venous insulin and proinsulin concentrations under glucose infusion]

In 8 female patients carbohydrate tolerance was proved by means of glucose infusion test 3 days after cholecystectomy. Parameters analyzed in portal and peripheral vein blood are compared with that of 47 healthy persons. All patients demonstrate a pathological carbohydrate tolerance after cholecystectomy, further characterized by an increased lipolysis, a paradoxical rise of HGH, a diminished insulin secretion during the early and increased IRI output in the second phase. There is a significant positive correlation between portal and peripheral vein IRI concentration despite the rising portalperipheral venous IRI difference with raised portal venous IRI concentration. Corresponding differences for proinsulin concentrations can be established in the early phase only. Relations existing between blood glucose and IRI are shown by multiple regression analysis. They suggest that the altitude of IRI concentration is determined by previous blood glucose concentration.     

Results of long-term biguanide therapy as a preventive measure in protodiabetes]

55 patients with pathological glucose tolerance received a long term treatment with buformin (200 mg daily). In 43 of the protodiabetics the duration of treatment was one year, in 29 of them two years and in 11 three years. The age of the patients was 38 years and the mean relative body weight was 118 per cent. The effect of buformin on glucose tolerance and insulin secretion was tested with the glucose infusion test before and after the periods of treatment. After one year we found in 58 per cent, after two years in 69 per cent and after three years in 64 per cent of the protodiabetics an improvement of glucose tolerance. In these groups the results showed a rise of the IRI in the low responder and a decrease of the IRI in the high responder. The good effects on glucose tolerance were not demonstrable in the compared groups with long-term treatment of diet only.     

Studies of glutamate dehydrogenase. Regulation of glutamate dehydrogenase from Candida utilis by a pH and temperature-dependent conformational transition.

Glutamate dehydrogenase from Candida utilis undergoes a reversible conformational transition between an active and an inactive state at low pH AND low temperature. This conformational transition can also be followed by fluorescence measurements. The temperature-dependent equilibrium between the active and the inactive state is characterized by a transition temperature of 10.7 degrees C and a delta H value of 148 kcal/mol (620 kJ/mol). The temperature dependence of the enzymic activity above 15 degrees C yields an activation energy of 15 kcal/mol (63 kJ/mol), a larger value than that for the beef liver enzyme (9 kcal/mol; 38 kJ/mol). In contrast to the yeast enzyme the Arrhenius plot is linear and, therefore, the beef liver enzyme is not transformed into an inactive conformation at low temperatures. Sedimentation analysis shows that the inactivation of the Candida utilis enzyme is not caused by change in the quaternary structure. The pH dependence of the conformational transition at low pH measured by fluorescence change is characterized by a pK value of 7.01 for the enzyme in the absence and of 6.89 for the enzyme in the presence of 2-oxoglutarate with a Hill coefficient of 3.4 in both cases. Similar results are found when the pH dependence of the enzymic activity is analyzed. With the beef liver enzyme the same pK value is obtained but with a Hill coefficient of 1 indicating cooperativity only in the case of the Candida utilis enzyme. The best fit of the pH dependence of the rate constants of the fluorescence changes was obtained with pK values of 7.45 and 6.45 for the active and the inactive state respectively. In this model the lowest time constant which is obtained at the pH of the equilibrium was found to be 0.05 s-1. Preincubation experiments with the substrate 2-oxoglutarate but not with the coenzyme shift the equilibrium to the active conformation. The coenzyme obviously reduces the rate constant of the conformational transition. The sedimentation coefficient (SO20, w) and the molecular weight were found to be 11.0 S and 276 000, respectively. The enzyme molecule is built up by six polypeptide chains each having a molecular weight of 47 000.