Distinguishing benign from malignant parotid gland tumours: low-dose multi-phasic CT protocol with 5-minute delay.

OBJECTIVES: To explore the percentage enhancement wash-out ratio (PEW) and relative PEW (RPEW) of low-dose multi-phasic computed tomography (CT) in distinguishing benign from malignant parotid gland tumours. METHODS: This study was approved by the ethics committee, and informed patient consent was obtained. 51 patients with parotid tumours proven by histopathology received CT, including 18 with pleomorphic adenomas, 14 with Warthin's tumours and 19 with malignant tumours. Size and attenuation of parotid tumours were measured. Compared with 5-min attenuation, the 30-s and 90-s PEW (PEW(30,) PEW(90)) and RPEW (RPEW(30), RPEW(90)) were calculated. RESULTS: There was a significant difference in PEW(30), RPEW(30), PEW(90) and RPEW(90) in the parotid neoplasms groups (P < 0.01), and statistical significance existed simultaneously in pleomorphic adenomas vs malignant tumours and Warthin's tumours vs malignant tumours according to SNK-q test. The optimal diagnosis results of malignancy with 100% specificity (32/32) was obtained by using a combination of the following criteria: -70% > PEW(30) < 36%, -30% > PEW(30) < 19%, PEW(90) > 12%, and the sensitivity (74%) for diagnosis of malignancy was yield. CONCLUSIONS: Wash-out ratio may assist in differentiating the benign from malignant parotid gland tumours. Combining the percentage of enhanced wash-out ratios of CT protocols can yield diagnostic results for malignancy.

Further investigation on nuclear transplantation in different orders of teleost: the combination of the nucleus of Tilapia (Oreochromis nilotica) and the cytoplasm of Loach (Paramisgurnus dabryanus).

The nucleus of a blastula cell from Tilapia (Oreochromis nilotica, family Cichlidae, order Perciformes) was transplanted into an enucleated egg of Loach (Paramisgurnus dabryanus, family Cobitidae, order Cypriniformes). From among 3747 nucleo-cytoplasmic hybrid (NCH) eggs two NCH larval fish (0.05%) were obtained; one died on the 6th day and the other died on the 12th day after the operation. Morphological examinations showed that both NCH larval fish had developed normally with an opened mouth except they could not take food after complete utilization of their egg yolk on the 5th day of development. The possible mechanisms for obtaining such inter-order NCH larval fish are discussed. This is the first report indicating that inter-order NCH larval fish can be obtained in spite of their evolutionary divergence.

Developmental incompatibility between cell nucleus and cytoplasm as revealed by nuclear transplantation experiments in teleost of different families and orders.

Teleosts from different families and orders were used as materials for nuclear transplantation experiments. (1) The nuclei of goldfish (Carassius auratus, family Cyprinidae, order Cypriniformes) were transplanted into the enucleated egg cytoplasm of loach (Paramisgurnus dabryanus, family Cobitidae, order Cypriniformes) and vice-versa. (2) The nuclei of Tilapia (oreochromis nilotica, order Perciformes) were transplanted into the enucleated egg cytoplasm of goldfish (Carassius auratus, order Cypriniformes). The chromosome number of the nucleus donor fish is different from that of the cytoplasmic recipient fish in each of the two combinations. In the first case, only a few early nucleo-cytoplasmic hybrid (NCH) larval fish were obtained in each combination. In second case, even though a high percentage of NCH blastulas were also obtained, the majority of them died at the same developmental stage, except a few which survived until early gastrula stage. The examination of the metaphase chromosome figures of the NCH blastulas or embryos obtained in all three combinations indicated that they were of nucleus-donor type. The developmental rates of all the NCH eggs were similar to those of cytoplasmic-recipient type. Scanning electronmicroscopy examination showed that the morphology of NCH blastula cells, which were obtained from the combination of Tilapia nucleus and goldfish cytoplasm, manifested obviously abnormal features and the cells were arrested at different stages of cell disintegration. Two-dimension polyacrylamide gel electrophoretograms of the homogenates of Tilapia, goldfish and their NCH blastula cells showed that the protein synthetic pattern of NCH blastula was similar to that of Tilapia nucleus type. The results of experiments which failed to obtain NCH adult fish in all three combinations can be explained as a result of developmental incompatibility between the donor nucleus and the enucleated recipient egg cytoplasm, which were from distantly related fish species. And the chromosome numbers of all the component fish of the three combinations which were examined in the experiment and shown to be quite different from each other in the tested fish, should not be overlooked as one of the essential factors causing the developmental incompatibility in NCH fish in this experiment.

Intravenous tryptophan tolerance test for liver function.

An intravenous tryptophan tolerance test (ITrpTT) was designed for liver function since 95% Trp is metabolized by the liver. After an intravenous loading dose of 4 mg/kg body weight, serum levels of both free (F) and total (T) Trp were determined at 45 and 60 minutes. In normal controls and nonhepatic-disease patients, F45 (60) and T45 (60) did not exceed 7 mumol/L and 80 mumol/L, respectively, and F/T ratio not greater than 0.14. These were set up as cutoffs of upper normal limits. The test was abnormal in 87.5% of chronic persistent hepatitis (CPH) characterized by elevation of T45 (60), 100% of chronic active hepatitis (CAH) by elevation of F45 (60) and/or T45 (60), and 100% of hepatic cirrhosis by increase in F45 (60) and F/T ratio but not in T45 (60). The test seems to be more sensitive than the conventional tests for liver function. However, one should be cautious in interpretation of the test as there are some factors which might influence the Trp metabolism like exercise, alcoholism, corticosteroids and enzyme-inducers. It merits as an indication of liver dysfunction only when these factors are considered and excluded.

[A study of the relationship between tryptophan metabolism and hepatic pathologic changes in chronic viral hepatitis].

The results of intravenous tryptophan tolerance test and its relationship with hepatic pathologic changes were studied in 47 patients with chronic viral hepatitis (CVH). It is shown that patients with CVH whether chronic persistent hepatitis (CPH) or chronic active hepatitis (CAH), the average value of total tryptophan were above 97 mumol/L (normal less than or equal to 85 mumol/L). There was no significant difference between the CPH and CAH groups (P greater than 0.05). In CPH, the value of free tryptophan (F) was all normal (normal less than or equal to 7.5 mumol/L), but in CAH, the average value of F was above 8 mumol/L. There was much difference (P less than 0.01) between the two groups. Moreover, there was also significant difference between the mild and severe CAH groups (P less than 0.05). It is found that retention of intravenous F is closely related to the degree of hepatic tissue necrosis the presence of balloon cells and acidophilic bodies as well as the severity of intralobular and portal inflammatory reaction.

[Effect of guzhen recipe on glucocorticoid receptor in senile rate thymocyte].

The effects of Guzhen Recipe (GZ) which composed of Polygonum multiflorum, Cistanche deserticole, Rubus chiagii etc, on the number of thymocyte glucocorticoid receptor (GCR) sites, the GCR nuclear translocation rate, and the activity of serum thymic factors etc in senile rats were observed. The results showed: The number of thymocyte GCR sites, the contents of cytoplasmic protein, nuclear RNA and DNA, the thymus weight/body weight ratio and the serum thymic factors in senile rats were significantly decreased, while thymocyte GCR nuclear translocation rate increased obviously than that of young control rats. GZ, however, was capable of improving the above-mentioned changes of thymus in senile rats markedly, suggesting that GZ might weaken the inhibitory effect of glucocorticoid on the thymus by means of suppressing the translocation activity of GCR from cytoplasm to nucleus in senile rats, thus enhance thymus-dependent immune function in senile rats.

Nuclear transplantation in teleosts. Hybrid fish from the nucleus of crucian and the cytoplasm of carp.

Hybrid fish are obtained from the combination of nucleus and cytoplasm from two genera of fresh-water teleosts using the technique of nuclear transplantation (i.e. the combination of the nucleus of crucian (Carassius auratus) and the cytoplasm of carp (Cyprinus carpio]. Morphological characteristics of these hybrid fish that have been examined so far indicate that some features such as barbs, pharyngeal teeth, the number of scales along the lateral line, and the number of vertebrae are similar to those of crucian. Some of the hybrid fish grow to normal adult fish.