[A report of surveillance on acute diarrhoeal diseases in Wuwei Prefecture from 1987 to 1988]

Surveillance on acute diarrhoeal diseases in Jinta County, Wuwei City for two successive years from January 1987 to December 1988 showed that the annual average incidence of diarrhoeal diseases was 0.079-0.124. The total detection rate of the etiologic agent was 58.95%. Bacterial infection was predominant. Ten species of pathogenic bacteria were detected, of which shigella remained the prevalent bacteria among which flexneri appeared as the predominant species after a decline for several years since early 1980s. The percentage of rotavirus was rather low. Diarrhoea was related to multiple factors. Children under 5 years old should be regarded as the target population for the prevention. Early detection of carriers has great significance in the prevention and control of diarrhoea.

Mutants defective in chromosome partitioning in E. coli

Recent experimental results suggest that replicated daughter chromosomes (nucleoids) in Escherichia coli move non-progressively and abruptly at an early stage of the D (division) period from midcell toward the cell quarter positions, which will become the centres of the daughter cells. The chromosome positioning at the quarter positions was found to be controlled by the muk gene products. In muk mutants, normal size anucleate cells are spontaneously produced during cell division. The mukA gene is identical to the tolC gene encoding an outer membrane protein. The mukB gene codes for a 177-kDa protein. The amino acid sequence of the MukB protein deduced for the nucleotide sequence suggests that the MukB protein has five characteristic secondary structure domains: an amino-terminal globular domain containing a consensus sequence binding with ATP or another nucleotide. The central region of the protein consists of two alpha-helical coiled-coil domains and one globular domain. A carboxyl-terminal globular domain is rich in cysteine and positively charged residues arginine and lysine. Two MukB protein molecules might form a homodimer in the coiled-coil regions. The predicted secondary structure of the MukB protein suggests that the protein provides the force required for the positioning of nucleoids from midcell toward the cell quarters. The mukC and mukD genes are located at 88 and 41 min of the chromosome map, respectively.

A preliminary study of radioimmunoimaging by 131I-COC183B2 monoclonal antibody in patients with epithelial ovarian cancer

Monoclonal antibody 131I-COC183B2, developed in our laboratory and proved to fit for human treatment was injected intraperitoneally or subcutaneously in 13 patients. In 8 cases with i.p. injection the disease corresponded with the image, i.e. 3 primary ovarian epithelial cancers showed positive images, 1 ovarian Krukenberg tumor was negative and the other 4 negative images included 1 uterine myoma and 3 ovarian teratomas. In the subcutaneous injection group, 4 cases had ovarian carcinoma, surgery and chemotherapy. Two negative images corresponded with the clinical status-in good health, another negative case had metastatic left supraclavicular lymph node due to ovarian mucinous adenocarcinoma. The last negative image in this group was a case of benign ovarian teratoma which was proved after surgery. The 1 positive case was waiting to be proved by a scheduled third operation. The computer scintigram calculation of T/NT was 5.35 to 13.7. The results suggest that this monoclonal antibody can be used for radioimmunoimaging for the localization of ovarian carcinoma, which is not only helpful for clinical staging and differential diagnosis but is also a good follow-up method.

Epicardial boundary detection using fuzzy reasoning

A fully automated system for detecting the endocardial and epicardial boundaries in a two-dimensional echocardiography by using fuzzy reasoning techniques is proposed. The image is first enhanced by applying the Laplacian-of-Gaussian edge detector. Second, the center of the left ventricle is determined automatically by analyzing the original image. Next, a search process radiated from the estimated center is performed to locate the endocardial boundary by using the zero-crossing points. After this step, the estimation of the range of radius of a possible epicardial boundary is carried out by comparing the high-level knowledge of intensity changes along all directions with the actual image intensity changes. The high-level knowledge of global intensity change in the image is acquired from experts in advance, and is represented in the form of fuzzy linguistic descriptions and relations. Knowledge of local intensity change can therefore be deduced from the knowledge of global intensity change through fuzzy reasoning.

[The natural variance of transient myocardial ischemia in coronary artery patients]

Sixty patients of CAD were studied with 24 and 48 hours ambulatory electrocardiogram monitoring. The day-to-day natural variances of transient myocardial ischemia in this group were analysed. The ranges of variation of myocardial ischemia based on a 95% confidence interval were confirmed. The results showed that the day-to-day variances of ischemia between the different days were: (1) 43% in number of ischemia episodes, (2) 76% in duration, (3) 53% in integration, and (4) 48% in maximal degree of ST depression.

[Electron spin resonance (ESR) study on hair of rats with diabetic cataract]

The hair taken from 40 rats with diabetic cataract and 20 normal controls was tested by using ESR. It was found that the 'g factor' of the hair of the rats with diabetic cataract is higher than that in normal controls. The intensity of ESR signals of the hair taken from rats with diabetic cataract is three times higher than that of ESR signals of the hair from the normal controls. The results have suggested a good reappearance and a remarkable increase in number of the free radicals and other particles of paramagnetic substances during the course of the development of the rats' diabetic cataract. The study provides new scientific data for the theory of free radicals damaging to the crystal in the process of the formation of diabetic cataract.

A human monoclonal antibody HMD4 against ovarian carcinoma associated antigen

Lymphocytes from regional lymph nodes of patients with ovarian carcinoma were immortalized by fusing them with a nonsecreting cell line of murine myeloma (Sp2/0-Ag14). The fusion rate was 0-87.5%. By early cloning and recloning, a hybrid cell line, named HMD4, was established. It has stably secreted human IgG for more than 15 months. Chromosome analysis showed the characteristics of human-mouse hybridoma. The cells of HMD4 were injected into the abdominal cavities of nude mice and 2-3 weeks later large quantities of ascites were obtained. Human IgG of lambda light chain was detected and purified from the ascites. The specificity of HMD4 human McAb was tested by ABC or PAP immunoperoxidase stainings of paraffin-embedded tissue sections, cryostat sections, cell smears of various tissues and different cancer cell lines. 60.5% (26/43) of epithelial ovarian cancers was positive, while nonepithelial ovarian cancers, most cancers from other organs and almost all nonmalignant and normal tissues were negative. The molecular weight of the antigen recognized by HMD4 was 55 KDa determined by Western blotting. The problems of maintaining the IgG secreting function of human-mouse hybridoma and its screening were also discussed.

Generation and characterization of three monoclonal antibodies to human ovarian epithelial adenocarcinomas

Three murine monoclonal antibodies COCL66-9, COC183A5 and COC183B2 were raised against human epithelial ovarian adenocarcinoma with soluble antigens. The monoclonal antibodies were stable after culture and stored under 80 C for 9 to 20 months. The subclass and titre were all examined and the reactivities were tested on various paraffin embedded tissue sectionism by immunoperoxidase stainings. The results of positive staining against ovarian epithelial adenocarcinoma were 77.7%, 87.2% and 75.6% for COC166-9, COC183A5 and COCL83B2 respectively. Human ovarian carcinoma xenograft in nude mice were radioimaged after 131I-COC183B2 administration. Gamma scintigraphy demonstrated specific localization of the radiolabeled monoclonal antibody on these tumors. The results showed a bright future for immunodiagnosis and immunotherapy.

[Pressor response induced by glutamate injection into caudal ventrolateral part of periaqueductal gray matter and its efferent pathway in brain-stem]

In urethane-anesthetized, tubocurarine-immobilized artificially ventilated rats, the following results were observed: (1) Sodium glutamate (Glu) microinjection into the caudal ventrolateral part of the periaqueductal gray matter (PAG) produced a marked rise in blood pressure. (2) This effect was attenuated by phentolamine or propranolol but not by atropine, injected bilaterally into the rostral ventrolateral medulla (RVL), indicating that this pressor response is mediated by RVL and alpha- and beta-receptors. (3) Propranolol-injection into RVL also attenuated the pressor response induced by electrical stimulation of the nucleus parabrachialis ventralis (NPV), while the pressor response initiated by injecting Glu into the same area (NPV) was not affected. Taken together with the previous findings that phentolamine blocks the pressor response produced by NPV-electrostimulation, but not of Glu-injection into NPV, the above results suggest that neurons in the caudal ventrolateral part of PAG may either send axons passing through the nucleus parabrachialis (NPB) and directly acting upon beta-receptors in RVL, or relay in NPB and act indirectly on alpha-receptors in RVL to produce the pressor response.

C-reactive protein, leukocytes, and fever after central IL 1 and alpha-MSH in aged rabbits

Aged and young unanesthetized rabbits with intracerebroventricular cannulas were tested in experiments designed to determine whether increases in plasma C-reactive protein (CRP) level and leukocytosis can be rapidly induced by central administration of crude buffy-coat supernatant commonly called endogenous pyrogen or interleukin 1 (IL 1). The results indicate that both acute-phase responses occur during fever caused by central administration of this supernatant and that they are generally detectable within 2 h. Although the febrile response was smaller in aged female rabbits, there was no decline in CRP or leukocyte responses, an observation that was not predicted. The antipyretic neuropeptide alpha-melanocyte-stimulating hormone (alpha-MSH) reduced fever caused by central IL 1 more effectively in the aged rabbits. alpha-MSH likewise inhibited the CRP and leukocyte responses to central IL 1. The results confirm that CRP and leukocyte responses can be driven by a central IL 1 signal and further indicate that the response can occur rapidly, consistent with direct central nervous system control of the acute-phase responses. The findings indicate that the acute-phase responses depend in part on the age of the host and that the responses can be modulated by an endogenous central nervous system peptide with known antipyretic and immune modulatory properties.

Eugenol: antipyretic activity in rabbits

The analgesic agent eugenol reduced fever when given intravenously in small doses to rabbits made febrile by interleukin 1. To test this observation further, the drug was given intragastrically and its antipyretic effect was compared with that of a molar equivalent dose of acetaminophen. Eugenol was more effective in reducing fever than acetaminophen. Tests with intracerebroventricular injections indicated that eugenol could act centrally to reduce fever in doses much smaller than those which were effective peripherally. Other tests with the presumed fever mediators sodium archidonate and prostaglandin E2 (PGE2), suggest that the central action of eugenol is similar to that of acetaminophen. Eugenol, a derivative of clove oil, has marked antipyretic activity when given intravenously, intragastrically and centrally and may reduce fever primarily through a central action that is similar to that of common antipyretic drugs such as acetaminophen.

Electrocoating carbon fiber microelectrodes with Nafion improves selectivity for electroactive neurotransmitters

A method which improves carbon fiber microelectrode selectivity for cationic amines by electrocoating the fiber with a thin film of the ionic polymer, Nafion, is described. The selectivity and response speed of these electrodes for the detection of electroactive cationic and anionic species found in brain extracellular fluid was evaluated using differential pulse voltammetry and chronoamperometry and compared to uncoated fibers. Carbon fiber microelectrodes electrocoated with Nafion are highly sensitive to cationic amines such as dopamine and serotonin and have minimal sensitivity to anions such as ascorbic acid and uric acid at physiological concentrations.

Is the endogenous antipyretic neuropeptide alpha-MSH responsible for reduced fever in aged rabbits?

The reduced febrile response in aged man has been noted since the beginning of clinical thermometry. Our previous research on aged rabbits and squirrel monkeys disclosed a similar reduced fever, presumably due to a decrease in central receptors for endogenous pyrogen. However, because central alpha-melanocyte stimulating hormone (MSH) appears to have a potent role in physiological control of fever, it may be that increased release of the peptide is responsible for the reduced febrile response in aged animals. To test this idea, antiserum specific to MSH was administered intracerebroventricularly to rabbits of known age. The antiserum given according to three schedules of treatment augmented fever caused by IV injections of interleukin-1 (IL-1) in young (less than 2 years) male and female rabbits. Aged female rabbits (3-5+ years) and females aged 2-3 years showed significant augmentation of fever only after pretreatment plus acute injection of antiserum. A single ICV injection of MSH (200 ng) reduced fever in all groups with the greatest antipyretic effect in the aged females. The results indicate that while aged rabbits have an increased antipyretic response to central MSH, binding of the endogenous peptide does not result in marked increases in fever in these animals. Thus, whereas a change in central MSH sensitivity may contribute to reduced fever in aged homeotherms, a reduction in central pyrogen receptors appears to be the most parsimonious explanation.

The study of antibodies and antigens dissociated from the immune complexes extracted from ovarian carcinoma ascitic fluid

In previous studies in our laboratory, heteroantisera were produced in rabbits by immunization with extracts of ascitic fluids from ovarian epithelial carcinomas. Reverse passive hemagglutination (RPHA) assay of these sera was used for the immunodiagnosis of ovarian cancer. Antibodies attached to lysed sheep red blood cells were able to detect tumor antigens in 63% of ovarian carcinoma sera. In the present study we have shown that the antigens detected in these assays are in fact contained in circulating immune complexes and are recoverable by disassociation with 8 M urea and separation of antibody and antigen by ion exchange chromatography. The antibodies thus obtained from immune complexes (IC) were assayed by indirect immunofluorescence against a variety of paraffin-embedded tissue sections. Poorly differentiated ovarian epithelial carcinomas and papillary serous adenocarcinomas, as well as the tumors grown by implantation of the latter in nude mice, were all positively stained, while the Krukenberg tumor metastatic to the ovary, the benign ovarian cyst, the normal ovary, and the normal fallopian tube were all negative. Complete blocking of immunofluorescence staining by prior absorption of antibody with the dissociated antigen was achieved. The present study demonstrates that the antibodies and antigens dissociated from the immune complexes isolated from the ascitic fluids provide useful reagents for immunodiagnosis.

Effect of ascorbic acid on protein synthesis and collagen hydroxylation in continuous flow organ cultures of adult mouse periodontal tissues

A continuous flow organ culture system (CFCS) was used to determine the effect of ascorbic acid on the synthesis of collagen and noncollagenous protein by bone of the alveolar process and periodontal ligament in organ cultures of adult mouse periodontium. For the last 24 h of 2 day cultures, 5 microCi/ml 3H-proline was added to the medium. Highly purified collagenase was used to separate the collagenous and noncollagenous proteins and the incorporation of isotope into each fraction measured. Collage synthesized in the presence of less than 10 micrograms/ml ascorbic acid was found to be highly under-hydroxylated (pro:hypro ap. acts. 2.3-3.1) in both tissues. When the ascorbic acid levels were between 25 and 100 micrograms/ml, the synthesis of collagenous proteins was selectively stimulated and hydroxylation significantly improved (pro:hypro sp. acts 1.72-1.89). The effect of ascorbic acid was not related to tissue viability since tissues cultured initially in the absence of ascorbic acid were able to recover completely when compared to controls given ascorbic acid continuously. The proportion of radioactivity in collagen and noncollagenous protein, collagen hydroxylation, and percentage of collagen synthesized as type III (av.23%) in bone of the alveolar process was similar to that found in vivo. However, in the periodontal ligament in vitro the proportion of noncollagenous protein synthesized was increased from 70% to 87% and the percentage of type III collagen increased from 14% to 26% compared to in vivo results.

Determination of L-ascorbic acid levels in culture medium: concentrations in commercial media and maintenance of levels under conditions of organ culture

The method of Deutsch and Weeks was modified to provide a reliable and reasonably quick method for assaying the L-ascorbic acid content of culture medium. The modified method was used to determine the decay of L-ascorbic acid under various conditions of culture and the concentration of the vitamin in commercially prepared media. The half-life of L-ascorbic acid in a modified New circulator gassed with 95% O2 + 5% CO2 was 1.5 hr.; and when gassed with 20% O2 + 5% CO2 + 75% N2, about 2 hr. In Petri dishes gassed with 20% O2 + 5% CO2 + 75% N2, the half-life of L-ascorbic acid was 0.9 hr. About 4% of the L-ascorbic acid was lost per day when medium was stored at 0 degrees C and about 9% per day when stored at 5 degrees C. When medium with an initial content of 300 microng per ml was stored at room temperature, the half-life was found to be 15.5 hr. The L-ascorbic acid in five commercially available media, which contain the vitamin in their formulations, was assayed immediately after their delivery to the laboratory. The values of L-ascorbic acid measured in these media were in all cases far lower than prescribed. A continuous-flow organ culture system has been designed which allows the provision of a relatively constant level of L-ascorbic acid to explant by taking advantage of the slow oxidation of L-ascorbic acid at 0 degrees C.