Potent inhibition of human tumor p21ras farnesyltransferase by A1A2-lacking p21ras CA1A2X peptidomimetics

The ras oncogene product p21ras requires farnesylation and subsequent plasma membrane association for its transforming activity. This key post-translational modification is catalyzed by p21ras farnesyltransferase, which transfers farnesyl from farnesylpyrophosphate to the cysteine of the CA1A2X carboxyl-terminal tetrapeptide of p21ras. In the present report, we describe potent inhibition of p21ras farnesyltransferase by CA1A2X peptidomimetics containing no peptidic amide bonds. We synthesized a series of CA1A2X analogues where the 2 aliphatic amino acids A1 and A2 were replaced by a hydrophobic spacer, 3-aminomethylbenzoic acid (AMBA). The peptidomimetic Cys-AMBA-Met, inhibits p21ras farnesyltransferase from human colon carcinoma (COLO-205) and Burkitt's lymphoma (Daudi) with IC50 values of 60 and 120 nM, respectively. Cys-AMBA-Met is 3-, 8-, and 9-fold (COLO-205) and 2-, 5-, and 7-fold (Daudi) more potent than the corresponding tetrapeptides of p21KB-ras (CVIM), p21N-ras (CVVM), and p21KA-ras (CIIM), respectively. Replacing methionine at the X position with negatively charged glutamate reduces its ability to inhibit the enzyme, whereas positively charged lysine at this position abolishes the inhibitory character of the peptidomimetic. A hydrophobic moiety at the X position, as in Cys-AMBA-Phe, retains potent inhibitory activity. Leucine in the X position of CA1A2X is a post-translational signal for protein geranylgeranylation rather than farnesylation, and, as expected, Cys-AMBA-Leu does not inhibit the enzyme. Furthermore, CVIM, CVVM, and CIIM are farnesylated by human p21ras farnesyltransferases and inhibit these enzymes by serving as alternative substrates. In contrast, the peptidomimetics described here are true p21ras farnesyltransferase inhibitors since none is farnesylated by this enzyme.

Localization and molecular heterogeneity of sulfated glycoprotein-2 (clusterin) among ventral prostate, seminal vesicle, testis, and epididymis of rats

In the rat reproductive tract, sulfated glycoprotein 2 (SGP-2) is present in the ventral prostate, seminal vesicle, testis, and epididymis. In the ventral prostate, SGP-2 is associated with the process of programmed cell death, while in the testis and epididymis a role for SGP-2 in sperm maturation has been proposed. Available information suggests that there are both inter- and intra-organ variations in SGP-2 localization, molecular forms, and response to androgen ablation. In the present study, localization of SGP-2 within the ventral prostate, seminal vesicle, and epididymis was compared by immunohistochemistry. In the ventral prostate of intact rats, immunoreactive SGP-2 was confined to a discrete population of epithelial cells lining the proximal ducts. Epithelial cells in other regions of the ventral prostate did not stain for SGP-2. A similar staining pattern was observed for the seminal vesicle; a small population of SGP-2-expressing epithelial cells was found in epithelium that did not stain for SGP-2. The epididymis also demonstrated a non-uniform staining pattern. The caput displayed strong immunoperoxidase reaction over the apical membrane and stereocilia of all principal cells. Principal cells also showed variable degrees of cytoplasmic staining ranging from weak to strongly positive. The corpus and cauda showed a similar staining pattern. After castration, all epithelial cells in the ventral prostate and seminal vesicle became intensely positive for SGP-2 staining. In the caput and cauda epididymis there was an increase in the number of principal cells demonstrating strong intracellular staining for SGP-2. These results suggest that as observed previously in the regressing ventral prostate, increased intracellular SGP-2 staining may also be associated with the regressing epididymis and seminal vesicle. Differences in molecular forms of SGP-2 were investigated by two-dimensional Western and lectin blots. Molecular forms of SGP-2 differed between testis and epididymis but were similar between ventral prostate and seminal vesicle. Prostate and seminal vesicle forms of SGP-2 differed from those of both testis and epididymis. Analysis of terminal carbohydrate present on the various SGP-2 molecular forms also confirmed the existence of heterogeneity. These results demonstrate the presence of multiple molecular forms of SGP-2 in various organs of the male reproductive tract in rats and suggest a possible variation in functional activity and/or half-life of SGP-2 in these organs.

Dopamine and acetylcholine cell density in the neuroleptic responsive (NR) and neuroleptic nonresponsive (NNR) lines of mice

The neuroleptic responsive (NR) and neuroleptic nonresponsive (NNR) selected lines of mice differ more than 10-fold in the ED50 for catalepsy induced by a wide variety of neuroleptics with a high dopamine D2/D1 receptor activity ratio, e.g., haloperidol. The NR and NNR lines also differ significantly in dopamine D2 somatodendritic receptor density; within the substantia nigra zona compacta and the ventral tegmental area, the increases in the NNR line are on average 33 and 48%, respectively. We now report that the NNR line has a higher number of dopamine neurons in the midrostral to the midcaudal aspect of the substantia nigra zona compacta. Within this region, the increase in dopamine cell number was on average 41%. In contrast to these data, there was no difference in cell number between lines in the ventral tegmental area. Thus, the increase of midbrain dopamine D2 receptor density in the NNR line can only be accounted for in part by an increase in the number of dopamine neurons. Although the number of dopamine neurons in the substantia nigra zona compacta was increased in the NNR line, the density of dopamine terminals in the caudate-putamen as estimated by the [3H] mazindol technique was modestly but significantly higher (8%) in the NR line. The selected lines also differed within the caudate-putamen in the number of cholinergic neurons. The NR line had a significantly higher number of cholinergic neurons in the rostral caudate-putamen. Overall, these data illustrate that selective breeding for neuroleptic response has yielded lines of mice with significant differences in both the cholinergic and dopaminergic systems of the basal ganglia.

Effects of rolipram and siguazodan on the human isolated bronchus and their interaction with isoprenaline and sodium nitroprusside

1 The effects of the selective inhibitors of cyclic AMP phosphodiesterase type IV (rolipram) and type III (siguazodan) and their interactions with isoprenaline and sodium nitroprusside have been studied in the human isolated bronchus. 2 On bronchi under resting tone rolipram was, in terms of potency (pD2 = 7.77 +/- 0.14, n = 8), very similar to isoprenaline (pD2 = 7.31 +/- 0.12, n = 12) and salbutamol (pD2 = 7.12 +/- 0.17, n = 10) and approximately 10 fold more potent than siguazodan (pD2 = 6.80 +/- 0.12, n = 6). In terms of efficacy (Emax, expressed as percentage of maximal effect induced by theophylline 3 mM), both rolipram and siguazodan were less efficient (Emax = 74 +/- 6.7%, n = 8 and 66 +/- 7.5%, n = 6, respectively) than isoprenaline (Emax = 98 +/- 0.4%, n = 12) and salbutamol (Emax = 83 +/- 2.4%, n = 10). 3 During precontraction induced by methacholine (3 x 10(-7) M) or acetylcholine (10(-3) M), concentration-response curves to rolipram and siguazodan were shifted to the right and maximal effects reduced. Rolipram was more potent than siguazodan and, in terms of efficacy, it was less active. 4. Rolipram 10(-8) and 10(-7) M but not siguazodan potentiated the effects of isoprenaline as shown by the shift to the left of the concentration-response curve to isoprenaline. Sodium nitroprusside-induced relaxation was not modified by either drug. 5. These results show that rolipram is a potent relaxant of the human isolated bronchus, potentiating the effects of beta-adrenoceptor stimulation and suggest that, as previously demonstrated in other species(guinea-pig, cow) (Tomkinson et al., 1993), there may be a connection between the beta2-adrenoceptor subtype, which predominate in human airway smooth muscle, and the cyclic AMP phosphodiesterase type IV.

Kinetics of peptide hydrolysis and amino acid decomposition at high temperature

Dipeptide hydrolysis and amino acid decomposition appear to follow a first-order rate law. The hydrolysis rate increases exponentially with increasing temperature in aqueous solution at both 265 atm and water steam pressures over the temperature range of 100 to 220 degrees C. Dipeptide hydrolysis has a lower apparent activation energy at 265 atm (44.1 KJ/mol) than at water steam pressure (98.9 KJ/mol). At lower temperatures (<200-220 degrees C), the rate of peptide bond hydrolysis is faster at 265 atm than at water steam pressure. At higher temperatures (>200-220 degrees C), however, peptide bond hydrolysis is slower at 265 atm than at water steam pressure. In aqueous solution, amino acid decomposition rates also increase exponentially with increasing temperature. Amino acid decomposition rates are much higher at 265 atm than at water steam pressure over the entire temperature range investigated.

Effects of capsaicin, (+/-)-CP-96,345 and SR 48968 on the bradykinin-induced airways microvascular leakage in guinea-pigs

The aim of this study was to demonstrate the involvement of neuropeptides in the increase in microvascular permeability induced by bradykinin in guinea-pig airways in vivo and to determine the type of receptor involved. Extravasation of intravenously injected Evans blue dye was used as an index of vascular permeability. Increase in plasma exudation induced by bradykinin (0.3 micrograms/kg, iv) was reduced or abolished by capsaicin (40 mg/kg, sc, 7 days before experiments), a drug which destroys neurokinins in the NANC nerve endings. (+/-)-CP-96,345 (3 mg/kg, iv), an antagonist of neurokinin NK1-receptors, abolished the increase of vascular permeability induced by bradykinin and reduced or abolished the effects of substance P (0.3 micrograms/kg, iv). The higher dose of (+/-)-CP-96,345 (10 mg/kg, iv) completely blocked the effects of substance P, but it did not modify those of neurokinin A (100 micrograms/kg, iv). In contrast, SR 48968 (0.1 and 0.3 mg/kg, iv), an antagonist of neurokinin NK2-receptors, reduced the increase of vascular permeability induced by neurokinin A without influencing the effects of bradykinin and substance P. These results demonstrate that a stimulation of the non-adrenergic non-cholinergic (NANC) nerves and a subsequent release of neuropeptides, especially of substance P, is involved in the effects of bradykinin.

The water-soluble component of Salvia miltiorrhiza Bge can promote macrophage synthesis of C4 in vivo and in vitro

A water-soluble component extracted from Salvia miltiorrhiza Bge has been used for many years in traditional Chinese medicine ('huo xie hua yu') for the treatment of the hyperviscosity syndrome. We demonstrate here that this extract promotes macrophage proliferation in vitro and enhances macrophage synthesis of the C4 component of complement. No increase in synthesis of other complement components by macrophages was observed. In a group of 20 patients with the hyperviscosity syndrome treated with an aqueous extract of Salvia, serum levels of C4 rose significantly over the course of treatment (mean pretreatment level 37.4 mg%, mean posttreatment level, 43.5 mg%; p < 0.01). The rise in C4 levels closely correlated with the disappearance of the patients' clinical symptoms.

Biological function of the retinoblastoma protein requires distinct domains for hyperphosphorylation and transcription factor binding

Despite the importance of the retinoblastoma susceptibility gene to tumor growth control, the structural features of its encoded protein (pRb) and their relationship to protein function have not been well explored. We constructed a panel of deletion mutants of pRb expression vectors and used a biological assay for pRb that measures growth inhibition and morphologic changes in pRb-transfected Saos-2 cells to correlate structural alterations of the pRb coding region with function. We tested the deleted proteins for the ability to bind to viral oncoprotein E1A and to the transcription factor E2F. We also measured the ability of the mutant proteins to become hyperphosphorylated in vivo and to be recognized as substrates in vitro by a cell cycle-regulatory kinase associated with cyclin A. We identified two regions of pRb that are required for E2F binding and for hyperphosphorylation. E1A binding domains partially overlap but are distinct from both of these other two regions. Biological function of pRb is dependent on retention of the integrity of both of these biochemically defined domains. These data support the model that pRb is a transducer of afferent signals (via the kinase that phosphorylates it) and efferent signals (through transcription factor binding), using distinct structural elements. Preservation of both of these features is essential for the ability of pRb to induce growth inhibition and morphologic changes upon reintroduction into transfected cells.

Formoterol and salbutamol inhibit bradykinin- and histamine-induced airway microvascular leakage in guinea-pig

1. The effects of the beta 2-adrenoceptor agonists, salbutamol and formoterol, on the increase of microvascular permeability induced by histamine or bradykinin in guinea-pig airways have been studied in vivo. Extravasation of intravenously injected Evans blue dye was used as an index of permeability. The effects of salbutamol and formoterol on the increase in pulmonary airway resistance induced by histamine or bradykinin have also been studied. 2. The increase in pulmonary airway resistance induced by histamine or bradykinin was totally inhibited by salbutamol and formoterol. The ED50 of the two mediators were 0.59 +/- 0.21 (n = 5) and 0.20 +/- 0.14 (n = 5) micrograms kg-1 respectively for salbutamol, and 0.13 +/- 0.12 (n = 6) and 0.02 +/- 0.01 (n = 6) micrograms kg-1 respectively for formoterol. 3. Salbutamol (10 and 30 micrograms kg-1) and formoterol (1 and 10 micrograms kg-1) inhibited the increase of microvascular permeability induced by histamine (30 micrograms kg-1) in the guinea-pig airways. The inhibitory effect was predominant in the trachea and the main bronchi, with a maximum inhibition of 20 to 50%. The two drugs had little or no inhibitory effect on the other structures studied, viz. nasal mucosa, larynx, proximal and distal intrapulmonary airways. 4. Salbutamol and formoterol (1 and 10 micrograms kg-1) abolished the increase in microvascular permeability induced by bradykinin (0.3 micrograms kg-1). This inhibitory effect of two beta-adrenoceptor stimulants was predominant in the trachea and the nasal mucosa where it was observed with 1 microgram kg-1 of the beta-adrenoceptor agonists.In the main bronchi, and in the proximal and distal intrapulmonary airways, the effects of bradykinin were abolished by 10 pg kg- of formoterol and salbutamol.5. The effects of bradykinin, but not those of histamine, were significantly reduced (nasal mucosa, main bronchi and distal intrapulmonary airways) or abolished (trachea, proximal intrapulmonary airways) by morphine 10mgkg-1, i.v. These results suggest that an indirect effect, through non-adrenergic noncholinergic (NANC) nerves is involved in the action of bradykinin on the microvascular permeability.6. In conclusion, intravenously injected beta-adrenoceptor stimulants can inhibit, partially or totally, the increase of airways microvascular permeability induced by intravenous histamine or bradykinin. However, these effects require doses that are higher than those that inhibit the increase in pulmonary airway resistance induced by these mediators. As suggested by the results obtained with morphine, the higher efficacy of beta2-adrenoceptor agonists versus bradykinin may occur through activation of presynaptic receptors of the non-adrenergic non-cholinergic (NANC) nerves preventing release of inflammatory neuropeptides such as substance P and neurokinin A.

Nucleotide sequence of gene 5 encoding the inner capsid protein (VP6) of bovine group C rotavirus: comparison with corresponding genes of group C, A, and B rotaviruses

To further study the molecular characteristics of group (gp) C rotaviruses, we produced, cloned, and sequenced cDNA to gene 5 of the Shintoku strain of bovine gp C rotavirus. The resulting clone was specific for gene 5 and was genetically related to the human and porcine gp C rotaviruses, as demonstrated by Northern blot hybridization analysis. The Shintoku gene 5 is 1352 nucleotides in length and has one open reading frame encoding a polypeptide of 395 amino acids with a predicted molecular mass of 44.5 kDa. Comparative sequence analysis indicated that: (i) the Shintoku gene 5 protein shared 88.4 to 90.6% homology with the VP6 of the human (Bristol and 88-220) and porcine (Cowden) strains of gp C rotaviruses, but only low homology with the VP6 of bovine gp A (RF) and human gp B (ADRV) rotaviruses (41.3 and 16.3%, respectively); (ii) the predicted secondary structure was highly conserved among the gene 5 proteins of the bovine, porcine, and human gp C rotaviruses; and (iii) seven highly conserved regions were identified for the first time in the deduced primary amino acid sequences of gene 5 of gp C and gene 6 of gp A rotaviruses. However, only three of these highly conserved areas were present in the regions of VP6, where the secondary structure was predicted to be similar for the rotavirus strains examined. These three regions may contribute to common epitopes between the two groups of rotaviruses. Our results, in comparison with data for other rotaviruses, indicate that gene 5 of the bovine gp C rotavirus codes for the major inner capsid protein (VP6).

[Effects of zinc deficiency and vitamin D deficiency on bone calcification and development of rats]

Zinc deficiency rat model was made by feeding zinc deficiency diet. The level of bone calcium of the zinc deficiency rats was significantly lower than that of the control rats. Their bone cortex was thinner and bone density decreased. The counts of their cartilage cells and hypertrophic cells of epiphyseal plate were less frequent, and the diameter of their hypertrophic cells was smaller than that of the controls. It suggested that zinc deficiency caused defective bone calcification which was similar to that in vitamin D deficiency. Zinc deficiency seemed to hinder the linear growth of long bone and might be the cause of dwarf.

Genetic variation in rotavirus serotype 4 subtypes

Serotype 4 rotavirus strains have been classified into two antigenic "subtypes" by a solid phase immune electron microscopy technique in which cross-absorbed animal polyclonal immune sera are used as the source of antibodies. The sequences of the gene encoding the outer capsid glycoprotein VP7 from a single serotype 4 rotavirus field strain identified as subtype A ("ST3-like") and from three field strains identified as subtype B ("VA70-like") were determined. A comparison of the deduced amino acid sequences indicated that 15 amino acid residues were divergent between subtypes but were conserved within a subtype. Three of these 15 amino acid residues (at positions 96, 212, and 217) were located in regions of the VP7 that have been defined as serotype-specific antigenic sites. These data suggest that VP7 subtype differences may result from critical amino acid substitutions within an immunodominant serotype 4-specific antigenic site. Whether these differences are an important mechanism in the epidemiology of rotaviruses requires further investigation.

D1 and D2 dopamine receptor distribution in the neuroleptic nonresponsive and neuroleptic responsive lines of mice, a quantitative receptor autoradiographic study

The present study uses quantitative receptor autoradiography to examine D1 and D2 receptor binding in the neuroleptic responsive and neuroleptic nonresponsive (NNR) lines of mice. The neuroleptic responsive and NNR mice have differed for at least eight generations by an order of magnitude in their sensitivity (ED50s) to catalepsy induced by neuroleptics with a high D2/D1 receptor activity profile. Across the entire rostral-caudal dimensions of the lateral caudate-putamen (CPu), of the dorsomedial CPu, the nucleus accumbens and substantia nigra zona reticulata, we found no difference in the density of [3H]SCH 23390 binding sites. [3H]Spiroperidol binding sites were not different in the dorsomedial CPu or nucleus accumbens but were significantly decreased (20-30%) in the NNR line in the caudal aspect of the lateral CPu. The NNR line also showed a significant elevation of D2 autoreceptors across all the midbrain dopamine cell groups (A8, A9 and A10); the increases ranged from 20 to 50%. Overall, the data show that selection of mice for response and nonresponse to neuroleptic-induced catalepsy is associated with significant changes in D2 but not D1 receptor density.

Analysis of the genetic diversity of genes 5 and 6 among group C rotaviruses using cDNA probes

Two partial cDNA clones of genes 5 (encoding the major inner capsid protein VP 6) and 6 (encoding a nonstructural protein) of the porcine group (Gp) C rotavirus (Cowden strain) were radiolabeled with 32P and used individually as probes in Northern and dot blot hybridization assays. The specificity of each probe was tested against genomic dsRNA from: (1) porcine Gp A, B, and C rotaviruses; (2) Gp C rotaviruses from different species; and (3) porcine Gp C rotavirus field strains with varying electropherotype patterns. Neither probe hybridized with ds RNA from the porcine Gp A and B strains under the stringency conditions employed in the study. However, the gene 5 probe hybridized with the corresponding gene from the homologous porcine and the heterologous human and bovine Gp C rotaviruses tested. The gene 6 probe hybridized with the corresponding gene from the homologous Cowden strain, but hybridized weakly with gene 6 from the human and bovine Gp C rotaviruses. Both probes recognized all six different porcine Gp C field strains, although with varying intensities. Our results demonstrate that the gene 5 and 6 probes used in this study are specific for Gp C rotaviruses. However, evidence for greater genetic variation in the gene 6 among porcine, bovine and human Gp C strains suggested that the gene 5 probe may prove more broadly reactive among Gp C strains from different species. cDNA probes used in our study should prove useful for the detection of Gp C rotaviruses in feces and facilitate epidemiologic studies.

[A comparative study of the two-dimensional echocardiography, ECG and selective coronary arteriography in detecting coronary artery disease]

This study was designed to compare the two-dimensional echocardiography (2 DE), electrocardiography (ECG) with selective coronary arteriography in 68 patients with chest pain for the evaluation of coronary artery disease. The sensitivity of 2 DE and ECG was 86.7% and 63.2%, P greater than 0.05. The specificity of 2 DE and ECG was 76.7% and 63.3%, P greater than 0.05. In patients with coronary artery stenosis greater than 50% of the diameter, the sensitivity was relatively 93.9% and 69.7%. In patients with stenosis greater than 75% of the lumen, that was 100% and 80%. In patients with old myocardial infarction, both of the sensitivity was 100%.

Comparison of human and porcine group C rotaviruses by northern blot hybridization analysis

The genetic relationship between human and porcine Gp C rotaviruses and between Gp C and Gp A or B rotaviruses was examined by Northern blot hybridization. Cross-hybridization studies using radiolabeled ssRNA transcript probes demonstrated that the human and porcine Gp C rotaviruses shared a high degree of nucleotide sequence homology in most of the eleven gene segments; the greatest sequence divergence was observed in gene 7. Neither the human nor the porcine Gp C probe hybridized strongly with gene segments from Gp A reference strains or a Gp B bovine rotavirus. These data indicate that genetically, porcine and human Gp C rotaviruses are closely related, whereas they are quite distinct from Gp A or B suggesting that porcine and human Gp C rotaviruses may have evolved from a common ancestral source.

[Change of T lymphocyte subsets in peripherial blood of children with malnutrition and zinc deficiency]

Sixty children with malnutrition were investigated in this study. The results showed a reduction of serum zinc in moderate and severe cases compared with the mild and normal groups. OKT3+, OKT4+ and OKT8+ cells in peripheral blood of mild malnutrition were significantly decreased in contrast to normal control. The reductive degree of OKT8+ and OKT4+ cells correlated with the severity of malnutrition. OKT8+, OKT4+ and OKT4+/OKT8+ ratio of moderate and severe malnutrition with infection were much lower than those without infection. Our findings suggested that main effective and regulative cells of cell-mediated immunity were impaired. OKT3+ and OKT4+ cells might be used as a sensitive index for early assessment of the immune function in malnutrition children.

[Clinical value of the Chengdu classification of non-Hodgkin's lymphomas]

Two hundred forty-nine cases of non-Hodgkin's lymphomas (NHL) were reviewed by using the working classification of NHL (Chengdu, 1985). The results showed that the patients of 249 cases of NHL ranging in age from 5 to 76 years, with the mean age of 42 of the types were separated into three major prognostic groupings as follows: 1. low (41 of 249 cases, small lymphocytic 27 cases, lymphoplasmacytoid 2 cases, follicular cleaved 7 cases, follicular cleaved and noncleaved 5 cases); 2. intermediate (58 of 249 cases, diffuse cleaved 28 cases, diffuse cleaved and noncleaved 27 cases, follicular noncleaved 3 cases); and 3. high grade malignancy (150 of 249 cases, diffuse noncleaved 49 cases, lymphoblastic 41 cases, immunoblastic 13 cases, polymorphic 39 cases, clear cell 2 cases, histiocytic 6 cases). Each group was significantly different from the others (P less than 0.05). The prognosis of patients with angioimmunoblastic lymphadenopathy like T-cell lymphoma (9 of 249 cases) was not more significant (P greater than 0.05) than that of patients with other polymorphic lymphoma (30 of 249 cases). The results showed this Chengdu classification of NHL is good for practice and usage in clinical evaluation and routine surgical pathology.

Analysis of the gene encoding the outer capsid glycoprotein (VP7) of group C rotaviruses by northern and dot blot hybridization

The genetic diversity of gene 8 (encoding the outer capsid glycoprotein VP7) among group (Gp) C rotaviruses was examined by Northern and dot blot hybridization. A cDNA clone of the porcine Gp C Cowden strain gene 8 was labeled with 32P by nick translation and used as a probe. The gene 8 probe hybridized with the corresponding gene of one human (88-196) and four porcine (Cowden, NB, WH, and Wi) strains of Gp C rotaviruses under both moderate (50% formamide, 5X SSC, and 42 degrees) and high (50% formamide, 5X SSC, and 52 degrees) stringency conditions. However, under high stringency conditions little or no hybridization was detected with the corresponding gene of one bovine (Shintoku) and three other porcine (Ah, HF, and KH) strains of Gp C rotaviruses. In control experiments, the Cowden gene 8 probe did not hybridize with Gp A (Gottfried strain) or Gp B (Ohio strain) rotaviruses. These data demonstrate that the Cowden gene 8 probe is Gp C rotavirus-specific and that genetic diversity exists among Gp C rotaviruses in the gene encoding the outer capsid glycoprotein VP7. Our gene 8 probe may be useful in hybridization assays for serotyping Gp C rotaviruses, analogous to the use of VP7 probes for serotyping Gp A rotaviruses. However, final confirmation of our genetic approach to serotype Gp C rotaviruses awaits the serologic analysis of these viruses.

[A micromethod for determination of serum zinc and copper concentration in infants aged 1-3 months in Chengdu]

A micromethod for the measurement of serum zinc and copper concentration of peripheral blood by wave-oscillopolarography is introduced in this article. The method is superior to the commonly used flame atomic absorption spectrophotometry (AAS) in its simplicity in sampling and operating and in its inexpensiveness. Yet the results are identical with those obtained by ASS, the method is good enough to replace ASS in clinical work, especially in the field of pediatrics. Serum zinc and copper concentrations in 243 infants aged 1-3 months in Chengdu were detected by this method. The data were found to be slowly distributed without age and sex differences. For the infants of 1-3 months in Chengdu, the reference values of serum zinc and copper concentration are 6.69-25.46 mumol/L and 8.70-28.07 mumol/L respectively.

Human rotavirus strain 69M has a unique VP4 as determined by amino acid sequence analysis

The group A rotavirus strain 69M has recently been classified as a new rotavirus serotype, G8, based on the antigenic specificity of its VP7 outer capsid glycoprotein. The fourth gene of 69M, which encodes the other outer capsid protein VP4, was sequenced. The gene is 2362 nucleotides in length and contains one long open reading frame beginning at the 10th nucleotide from the 5' end and terminating with a stop codon 22 bases from the 3' end. The encoded VP4 contains 776 amino acids. Comparative analysis of the deduced amino acid sequence with other rotavirus strains demonstrated that the VP4 of strain 69M shares 68.9 to 74.5% amino acid identity with the VP4 from strains known to represent four human rotavirus VP4 genetic alleles and 74.9 to 86.2% identity with VP4 from various animal rotaviruses. Northern blot hybridization with either radiolabeled ssRNA transcripts from 69M or cloned 69M gene 4 cDNA as probes indicated that the fourth gene of strain 69M is genetically distinct from any group A rotavirus gene 4 described thus far. These data suggest that at least one additional antigenic specificity of VP4 exists in circulating human group A rotavirus strains.