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Background We experienced a patient with multiple myeloma whose urine contained a considerable amount of Bence Jones protein (BJP), which demonstrated poor thermal reactivity in heat coagulation test. The mechanism for this phenomenon was assessed. Methods Immunoelectrophoretic analyses reveal that a band corresponding to BJP in the urine had 2,600 Dalton by reduction after glycosidase treatment, but not after sialidase treatment. In addition, the glycosidase-treated urine tested positive in heat coagulation test. Conclusions Glycosylation of the immunoglobulin light chain, which has rarely been seen, is the cause of the unexpected behavior of this patent's BJP in heat coagulation tests.

The effects of ovalbumin (OA) on heat coagulation of ovotransferrin (OT) were studied by heating at 65 °C for 10 min in 10 mM phosphate buffer, pH 7.0. The heat interactions between OA and OT were investigated by turbidity development and polyacrylamide gel electrophoresis. From the change in turbidities of various mixtures of 0.05% OT and OA induced by heating, it was found that OA had the inhibiting capacity against OT coagulation. The inhibiting capacity of OA was reduced by adding NaCl to OA-OT mixture on heating. The heat-denatured OA that was preheated above 70 °C exhibited markedly the inhibiting capacity against OT coagulation at 65 °C. A possible mechanism by which OA inhibited the OT coagulation was discussed. It was presumed that OA interacted mutually with OT by the electrostatic attractive force, unfolded together by heating, and then formed soluble aggregates with OT through intermolecular forces such as hydrophobic and disulfide bonds and, consequently, such a process might inhibit OT–OT interaction that led to coagulation.

The characteristics of dialyzed and freeze-dried egg white that was dry-heated under various conditions (70−125 °C, 0 min−6 h) were studied. The dry-heated egg whites (DHEWs, 120 °C) showed the formation of insoluble aggregates (coagula) within 50 min, turbid soluble ones (50 min−2 h), and transparent soluble ones (2−6 h) according to the dry-heating times when solubilized at 10% concentration (pH 7.4) and reheated at 60 °C for 3.5 min. A transparent DHEW solution without any coagula when reheated was obtained by using a shorter dry-heating time and elevating the dry-heating temperature. It was also found that NaCl suppressed the turbidity development of DHEW solution promoted by CaCl2. When 10% DHEW solutions (120 °C, >2 h) were mixed with fresh egg white at the ratio of 1:1 in volume and heated at 60 °C for 3.5 min, coagulum formations in their mixtures were inhibited. The patterns of native− and SDS−PAGEs and gel filtration suggest that soluble aggregates of ovalbumin formed in the dry-heating process ...

A CHANGE in pH when proteins are denatured has been reported by other workers1,2. When making observations of the change in pH of meat resulting from heat coagulation, we were struck both by the magnitude and by the variability of the change. Muscle is a highly buffered system3, and a change such as that observed, for example, from 5·6 to 5·9, indicates the production of a considerable amount of base.

To study the mechanism of the gel-strength increasing effect of sarcoplasmic proteins (Sp-P) on fish meat gel, the interaction between each component of Sp-P and actomyosin (AM) occurring during heating was examined. Heat coagulation temperature range was measured for each component by gradually heating the Sp-P extracts (I=0.05) from 9 fish species: 40-50 ℃ for 50K, 43K, and 23K; 50-60℃ for 94K, 60K, 40K, 30K, and 25K; 60-70℃ for 65K, 63K, 55K, and 35K; >70℃ for 20K components>. These components, however, remained in the mixed solution (I=0.7) of Sp-P and AM at a ratio of 1 to 2 even after heating at 80℃. This was attributable to the fact that the coagulable Sp-P components bound to AM molecules one after another at their coagulation temperatures were suspended in the solution.

Ovalbumin (OVA) was aggregated stepwise by dry heating at 120 degrees C with a gradual increase in its heating times (10 min-6 h). The inhibiting effects of DHOVAs (OVAs dry-heated for various times up to 6 h) on the heat coagulation of ovotransferrin (OT) were studied. DHOVAs and OT were solubilized at 5% (w/w) concentration with 10 mM sodium phosphate buffer, pH 7.4. Their solutions were mixed at the volume ratio of 1:1 and reheated at 60 degrees C for 3. 5 min. Some remarkable differences according to dry-heating time were observed: coagulum formations were greatly inhibited in the solutions mixed with DHOVAs treated for more than around 2.0 h, with decreasing turbidity as dry-heating time increased. In addition, the effects of reheating time and temperature, as well as those of pH and ionic strength, were also examined on coagulum formation and turbidity development in connection with dry-heating time. Thus, the inhibiting effects of dry-heated egg white on the heat coagulation of fresh egg white previously described were confirmed on the molecular level of OVA and OT.

Juices from pressed green grass and alfalfa have a high protein content and are used for producing proteinconcentrates. Heat coagulation is the most-used method for this product category. An alternative method is ultrafiltration which promises a product with a higher solubility. Both methods are carried out with two different raw materials. Alfalfa (Medicago sativa subsp. sativa) and ryegrass (Lolium perenne x multiflorum) were prepared underequal conditions to get a green juice. In an additional experiment, juice pressed from ensiled ryegrass was used as afeed for ultrafiltration with a very low cut off (1 kD). It was found that only a part of the crude protein, which can berecovered, is true protein. The crude protein recovery by ultrafiltration of ryegrass juice was 59% compared to 45%by heat coagulation. The rate of crude protein yield of alfalfa juice was 52% by ultrafiltration and 53% by heatcoagulation and centrifugation. It was shown that protein degradation under ultrafiltration conditions plays animportant role. During ultrafiltration of silage juice no selective crude protein retention was observed.

Publisher Summary About 80% of the protein in milk is casein. The casein is present as colloidal particles, the so-called “casein micelles.” Casein monomers have little secondary structure; therefore, they are not able to be denatured by heat. Nevertheless, an intensive heat treatment of milk results in coagulation, principally by aggregation of the casein micelles. The study on heat coagulation of milk products so far has focused almost exclusively on the effect of compositional and processing factors on the Heat Coagulation Time (HCT), which is the time needed at a certain high temperature (120-140°C) to cause visible coagulation in an agitated sample of milk. This chapter focuses on the application of fractal aggregation theory to the heat coagulation of milk products and presents some results of the application of fractal aggregation theory to the heat coagulation of milk products. It concludes that at the conditions where simple flocculation predominates, the heat coagulation strongly depends on the initial volume fraction of particles. Fractal aggregation theory describes this dependence rather well.

Journal of Dairy Research, 59 (2), ISSN:0022-0299, ISSN:1469-7629

To detect the influence of heat coagulation of middle meningeal artery (MMA) on plasma CGRP and SP levels in migraine rat triggered by nitroglycerin (NTG).Twenty-four female Wistar rats were randomly divided into four groups, with six rats in each group. In group A, rats were treated with isotonic saline; in group B, rats were injected subcutaneously with 10 mg/kg nitroglycerin to set up the animal model of migraine; in group C, rats were subjected to sham surgery by merely exposing MMA and then injected with nitroglycerin (10 mg/kg); and in group D, rats were firstly subjected to heat coagulation of MMA and, subsequently, injected with nitroglycerin (10 mg/kg). Following the injection, the animal's behavior was continuously recorded by an observer. Radioimmunoassay was employed to measure the amounts of CGRP and SP in venous plasma.Injection of 10 mg/kg nitroglycerin was able to trigger the animal model of migraine as evidenced by the appearances of a series of symptoms, such as, scratching head frequently, climbing cage and red ear. Rats in group A occasionally showed off scratching head, whereas, rats from group B and group C presented with much severe symptoms. Of note, rats in group D appeared slightly scratching head and climbing cage, without red ear compared with group B and C. At the same time, the amounts of plasma CGRP and SP in group B, group C, or group D were increased significantly compared with that of group A (P0.05). Furthermore, the plasma CGRP and SP levels in group D were much lower than that in group B and group C (P0.05), but there was no statistical difference between group B and group C (P0.05).Heat coagulation of MMA may relieve symptoms of rats following nitroglycerin infusion, possibly by inhibiting the release of CGRP and SP.

To investigate long-term effect on radiofrequency heat-coagulation (RF) endometrial ablation in treatment of anovulatory dysfunctional uterine bleeding (DUB).From Jul. 2001 to Nov. 2009, 1196 patients with DUB who were failed by medical treatment (including 127 patients with dysmenorrheal) were enrolled into this study in Jinan Millitary General Hospital. Those patients were divided into two groups according to age: 427 patients at age of or more than 45 years (average age 48 years) in Group A who were treated by RF procedure for amenorrhea;769 patients at age of less than 45 years old (average 37 years) in group B were treated by RF for controlling excessive menstrual bleeding. All the patients had the results of menstrual score (pictorial blood loss assessment chart, PBAC), hemoglobin (Hb), endometrial curettage pathology and hysteroscopy examination immediately after RF procedure; Some patients still had another endometrial curettage pathology and clinical results in 6 months after RF. The mean follow-up time was 72 months (range: 6 to 100 months). The evaluation criterion for RF treatment was to use optimal and significant effect measurements. For group A, the optimal treatment effect (cure) was defined as bleeding cessation and achieving amenorrhea that continued for more than 12 months after treatment. For group B, the optimal treatment effect(cure) was also defined as bleeding cessation and resuming normal menstruation which continued for more than 12 months after treatment. Significant treatment effect was defined as irregular, minor bleeding, but PBAC score less than 100 within 12 months. If patient symptoms and PBAC scores did not change compared with those before treatment, the treatment was defined as failure. For dysmenorrhea, the optimal treatment effect was disappearance for more than 12 months, the significant treatment effect was remission, and treatment failure was not changed from the pre-treatment baseline. The effective rate was the sum of that of the optimal and significant effect. One hundred and twenty-five patients with DUB treated by agents at the same time were chosen as control group.(1) The recent and long-term effective rates for bleeding cessation by RF:the total recent effective rates within 1 months were 94.82% (1134/1196), including 96.5% (412/427) in group A and 93.9% (722/769) in group B. The total curative rates for dysmenorrheal were 82.7% (105/127), including 86.4% (38/44) in group A and 80.7% (67/83) in group B. Pathology examination after hysteroscopy immediately after RF showed a completely and whole destroyed endometrium in group A, and a little rested endometrium in group B. The long-term effect rates for bleeding cessation by RF after 12, 24 and 36 months were 92.55% (969/1047), 93.9% (866/922) and 93.7% (609/650), respectively. PBAC and Hb in group A and group B within 12, 24, 36 and more than 36 months were improved significantly (P0.05). (2) COMPLICATIONS: the major complication was irregular minor bleeding in 1 to 2 months after treatment, the rate was 8.03% (96/1196). The second one was menorrhea in 3 months after RF, the rate was 5.18% (62/1196). This condition was corrected by the second RF. No hysterectomy was performed on those patients.RF is the safe, efficient and minimal invasive procedure in treatment for DUB. The mechanism of keeping long-term curative effect and preventing recurrence is due to endometrium inactivation and fibrosis by thermocoagulation.

Albumins and globulins were fractionated by coagulation at 70, 100, and 120°C and were studied by microscopic and electrophoretic methods. The coagulated albumins of a U.S. commercial hard red winter (HRW) wheat blend sample included larger aggregates than those of an Israeli spring wheat (SW). Dialyzed globulins appeared as finger-like patterns with embedded oil droplets and heat-coagulated globulins appeared as aggregates with fibril-like patterns. An increase in size of coagulated aggregates was observed as temperatures increased (70, 100, and 120°C). Differences in capillary zone electrophoresis (CZE) and sodium dodecyl sulfate (SDS) – polyacrylamide gel electrophoresis (PAGE) patterns between coagulates from samples of an Israeli SW and a U.S. commercial HRW wheat were seen at all the coagulation temperatures. SDS-PAGE patterns of coagulates obtained at lower temperatures exhibited relatively more intense bands of higher molecular weight components, and those obtained at higher temperatures exhibited relatively more intense bands of lower molecular weights.

In many parts of the developing world, the urine protein heat coagulation test is routinely used to screen for proteinuria in pregnancy. The aim of this study was to determine whether > or =1+ on a standardised heat coagulation test reliably detects significant proteinuria and to compare it with the dipstick test for urinary protein. Heat coagulation test, dipstick test and 24-hour urine protein excretion results of 102 women were compared. > or =1+ on heat coagulation test is as sensitive and specific as > or =2+ on the dipstick test in detecting proteinuria of > or =500 mg/day. The heat coagulation test, however, is less sensitive than > or =1+ on dipstick in detecting lesser degrees of proteinuria.

Milks with casein micelles larger or smaller than control milk were prepared by differential centrifugation. The heat stability of these modified milks increased markedly throughout the pH range 6.4 to 7.1 with decreasing casein micelle size. Within the region of the minimum in the heat coagulation time-pH profile, the control milk coagulated by a two-stage process, but the modified milks, because of their narrower casein micelle size distribution, coagulated by a single-stage process at the pH of minimum stability. The content of kappa-CN and protein hydration increased as the size of the casein micelles decreased, and the level of glycosylation of kappa-CN and protein surface hydrophobicity increased as a function of micelle size. The effect of casein micelle size on the heat stability of milk is likely to be related to changes in the above physico-chemical properties.