Influence of whipping temperature on the whipping properties and rheological characteristics of whipped cream.

The effects of whipping temperature (5 to 15 degrees C) on the whipping (whipping time and overrun) and rheological properties of whipped cream were studied. Fat globule aggregation (aggregation ratio of fat globules and serum viscosity) and air bubble factors (overrun, diameter, and surface area) were measured to investigate the mechanism of whipping. Whipping time, overrun, and bubble diameters decreased with increasing temperature, with the exception of bubble size at 15 degrees C. The aggregation ratio of fat globules tended to increase with increasing temperature. Changes in hardness and bubble size during storage were relatively small at higher temperatures (12.5 and 15 degrees C). Changes in overrun during storage were relatively small in the middle temperature range (7.5 to 12.5 degrees C). From the results, the temperature range of 7.5 to 12.5 degrees C is recommended for making whipped creams with a good texture, and a specific temperature should be decided when taking into account the preferred overrun. The correlation between the whipped cream strain hardness and serum viscosity was high (R(2)=0.906) and persisted throughout the temperature range tested (5 to 15 degrees C). A similar result was obtained at a different whipping speed (140 rpm). The multiple regression analysis in the range of 5 to 12.5 degrees C indicated a high correlation (R(2)=0.946) in which a dependent variable was the storage modulus of whipped cream and independent variables were bubble surface area and serum viscosity. Therefore, fat aggregation and air bubble properties are important factors in the development of cream hardness. The results of this study suggest that whipping temperature influences fat globule aggregation and the properties of air bubbles in whipped cream, which alters its rheological properties.

Modeling of the effect of freezer conditions on the hardness of ice cream using response surface methodology.

The effect of conventional continuous freezer parameters [mix flow (L/h), overrun (%), drawing temperature ( degrees C), cylinder pressure (kPa), and dasher speed (rpm)] on the hardness of ice cream under varying measured temperatures (-5, -10, and -15 degrees C) was investigated systematically using response surface methodology (central composite face-centered design), and the relationships were expressed as statistical models. The range (maximum and minimum values) of each freezer parameter was set according to the actual capability of the conventional freezer and applicability to the manufacturing process. Hardness was measured using a penetrometer. These models showed that overrun and drawing temperature had significant effects on hardness. The models can be used to optimize freezer conditions to make ice cream of the least possible hardness under the highest overrun (120%) and a drawing temperature of approximately -5.5 degrees C (slightly warmer than the lowest drawing temperature of -6.5 degrees C) within the range of this study. With reference to the structural elements of the ice cream, we suggest that the volume of overrun and ice crystal content, ice crystal size, and fat globule destabilization affect the hardness of ice cream. In addition, the combination of a simple instrumental parameter and response surface methodology allows us to show the relation between freezer conditions and one of the most important properties-hardness-visually and quantitatively on the practical level.

Induction of inducible nitric oxide synthase in hepatocytes isolated from rats with ischemia-reperfusion injury.

BACKGROUND: Recent evidence indicates that nitric oxide (NO) has a crucial role in hepatic ischemia-reperfusion (I/R) injury. However, little is known about how I/R influences the gene expression of inducible nitric oxide synthase (iNOS) in hepatocytes. Under inflammatory conditions, we compared the induction of iNOS in hepatocytes isolated from normal and I/R-treated rats. METHODS: Hepatocytes were isolated using the collagenase perfusion method from rats treated with I/R (30-minute ischemia of middle and left lobes, followed by 3-hour reperfusion) or sham operation (control): Primary cultures of rat hepatocytes were incubated with an inflammatory cytokine, interleukin-1beta (IL-1beta), to compare the iNOS induction/NO production between the 2 groups. RESULTS: Both control and I/R groups had no production of nitrite (a stable metabolite of NO) in the absence of IL-1beta. In the control group, IL-1beta stimulated dose- and time-dependent production of NO. The I/R group showed more than 2-fold increased levels of NO production. Western and Northern blot analyses revealed that the I/R group also showed increased levels of iNOS protein and its messenger RNA. CONCLUSION: These results suggest that I/R directly affects the inducibility of the iNOS gene in hepatocytes by IL-1beta. Increased NO may be associated with protective or toxic effects in hepatic I/R injury.

[Two cases of multiple liver metastases of colon cancer with systemic irinotecan and hepatic arterial injection of 5-FU].

We describe two patients with multiple liver metastases of colon cancer, who simultaneously received systemic irinotecan and hepatic arterial injection of 5-FU. In both cases, a notable partial response (more than 80%) in the hepatic metastases was observed. The patients could undergo chemotherapy without remarkable side-effects as out-patients. In the future, we shall perform a clinical study to evaluate the safety and dose limiting toxicity for the present combined chemotherapy.

High expression of thymidylate synthase leads to resistance to 5-fluorouracil in biliary tract carcinoma in vitro.

To evaluate the effect of chemotherapy of 5-fluorouracil (5-FU) in human biliary tract carcinoma, we studied 5-FU sensitivity, thymidylate synthase (TS) content, and dihydropyrimidine dehydrogenase (DPD) activity in 4 human biliary tract carcinoma cell lines compared to 12 various digestive carcinoma cell lines of human organs in vitro. 5-FU sensitivity in the cell lines was analyzed by MTT assay. TS content was analyzed by the [6-(3)H]FdUMP binding assay method, and DPD activity was analyzed by thin-layer chromatography (TLC). 5-FU IC(50) values of biliary tract carcinoma cell lines were significantly higher than those of the carcinoma cell lines of the other digestive organs: 97, 45, 119, and 194 times the concentration of the other digestive, pancreas, colon, and gastric carcinoma cell lines, respectively. TS content of biliary tract carcinoma cell lines was also significantly greater than that of the carcinoma cell lines of the other organs. No difference in DPD activity, however, was recognized between the carcinoma cell lines of each organ. TS content in the cell lines significantly correlated with 5-FU sensitivity, but DPD activity did not. Therefore, in the present study, TS expression was concluded to influence the high resistance to 5-FU of biliary tract carcinoma in comparison with the carcinomas of the other digestive organs.

Expression of thymidylate synthase in cancer of the ampulla of Vater.

The clinical and therapeutic significance of thymidylate synthase (TS) in cancers of the ampulla of Vater have not yet been reported. We immunohistochemically evaluated TS expression in 33 ampullary cancers using an anti-TS antibody. TS expression, clinicopathologic variables, and survival rates were examined and the correlations between these parameters were identified. Fifteen patients were found to express high levels of TS (high TS group), while 18 patients expressed low levels of TS (low TS group). No significant difference was found between TS expression and clinicopathologic factors. Univariate and multivariate analysis revealed that lymph node metastasis and pancreatic invasion are important variables for independently predicting post-operative survival. Although TS expression was not identified as an important factor for postoperative survival, recurrent cases in patients with chemotherapy existed only in the high TS group. In the present study, it was found that TS expression itself in cancers of the ampulla of Vater has no impact in predicting the prognosis of ampullary cancers, but a chemotherapeutic benefit of evaluating TS expression may exist.

SNP profile within the human major histocompatibility complex reveals an extreme and interrupted level of nucleotide diversity.

The human major histocompatibility complex (MHC) is characterized by polymorphic multicopy gene families, such as HLA and MIC (PERB11); duplications; insertions and deletions (indels); and uneven rates of recombination. Polymorphisms at the antigen recognition sites of the HLA class I and II genes and at associated neutral sites have been attributed to balancing selection and a hitchhiking effect, respectively. We, and others, have previously shown that nucleotide diversity between MHC haplotypes at non-HLA sites is unusually high (>10%) and up to several times greater than elsewhere in the genome (0.08%-0.2%). We report here the most extensive analysis of nucleotide diversity within a continuous sequence in the genome. We constructed a single nucleotide polymorphism (SNP) profile that reveals a pattern of extreme but interrupted levels of nucleotide diversity by comparing a continuous sequence within haplotypes in three genomic subregions of the MHC. A comparison of several haplotypes within one of the genomic subregions containing the HLA-B and -C loci suggests that positive selection is operating over the whole subgenomic region, including HLA and non-HLA genes. [The sequence data for the multiple haplotype comparisons within the class I region have been submitted to DDBJ/EMBL/GenBank under accession nos. AF029061, AF029062, and AB031005-AB031010. Additional sequence data have been submitted to the DDBJ data library under accession nos. AB031005-AB03101 and AF029061-AF029062.]

[Morphological studies on the renal papillae of the kidney in Japanese adults].

In the present study, 55 kidneys were obtained from 29 Japanese adults, sectioned frontally to expose their renal papillae, and were macroscopically observed. The average number of papillae per kidney was 12.87 +/- 3.09 (7 to 22); no differences by sex or laterality were found. The number of papillae was positively correlated with the number of minor calices (p < 0.01) and renal weight (p < 0.05). However, there was no correlation with the number of papillae and age. Additionally, a positive correlation was found between renal weight and the number of minor calices (p < 0.05). Based upon the number of the renal papillae in each renal calyx, the papillae were divided into "simple" and "complex" groups. The number of papillae in the complex group was 2 (bifid), 3 (trifid), or 4 (cruciate). These papillae were further grouped into two types, "separate" or "fused." Therefore, the papillae were classified into 7 types such as simple, bifid separate, bifid fused, trifid separate, trifid fused, cruciate separate, and cruciate fused. The appearance ratio of the above 7 types of papillae were as follow: simple (51.7%), bifid fused (23.4%), trifid fused (14.3%), bifid separate (6.0%), cruciate fused (4.1%), trifid separate (0.2%), and cruciate separate (0.2%). The number of simple papillae (214, 51.7%) was approximately the same as that of total complex papillae (200, 48.3%). In the complex group, the number of separate papillae (27, 13.5%) was quite fewer than that of fused papillae (173, 86.5%). The original papillae had the shape of a flat cone. The average long length of the bases of papillae were 6.7 mm in simple papilla, 10.3 mm in bifid fused papilla, 11.0 mm in bifid separate papilla, 11.9 mm in trifid fused papilla, and 13.7 mm in cruciate fused papilla. The more the number of papilla increases, the more the length of the bases of papilla becomes long. However, the short length of the bases and height in each papillae were not different. Simple and bifid papillae were mostly observed in the hilus, whereas trifid and cruciate were frequently found in the cranial part of the kidneys.

[Five cases of the double renal pelvis and ureter].

Five cases of the double renal pelvis and ureter were encountered among 340 cadavers for dissection practice. Number of minor calices and their surface area in these kidneys were calculated, and causal relationship to abnormal organogenesis was discussed. These 5 cases were formal exclusively in consist of males; 4 right sides and 1 left side, 2 complete duplications and 3 partial duplications. The 5 cases were divided into 2 groups by the number and surface area of minor calices in upper and lower pelvises as follows: 1) The number and surface area of minor calices in the upper pelvis and the lower pelvis were respectively equivalent to the mean value of those in one normal kidney (case 1). 2) The sum of the number and surface area of minor calices in the upper and those in the lower pelvises were equivalent to the mean value of those in one normal kidney (case 2-5). These cases give useful criteria for classification of the double renal pelvis and ureter.