[Treatment of congenital cataract with McIntyre co-axial I.A. cannula]

Thirty seven eyes with congenital cataract in with there a lot of transparent cortex were treated with McIntyre co-axial cannula. Primary posterior capsuloctomy after removing the cortex was performed on patients aged less 3 years; for patients over 3 years, their posterior capsule remained intact. After the operation, all cases got transparent pupillary space more than 5 mm in diameter. The visual acuities improved in 32 eyes and remained unchanged in 5 eyes. This procedure not only received satisfactory results, but also avoided side effects caused by capsuloctomy and reduced the possibility of general anesthesia accident and operation fee.

Preparation of diazotized polystyrene latex and its use in agglutination assays

The preparation of this immunological latex consisted of the following steps: the synthesis of polystyrene, polynitrostyrene, polyaminostyrene and polystyrene diazonium salt latex. The quantities of emulsifier and initiator used in the synthesis of the polystyrene latex were much larger than those used in the conventional method. Reduction of the polynitrostyrene latex involved adding latex dropwise to a large excess of 6% sodium hydrosulphite-2 N potassium hydroxide solution with sodium lauryl benzene sulphonate as an emulsifier. When the mixture was heated at 70 degrees C for 4 h, the emulsion of polyaminostyrene was diazotized. The polystyrene diazonium salt latex obtained was capable of combining with 20-40% by weight of antibody protein. The immunopolystyrene diazonium latex reagents showed a positive agglutination reaction of 78-91% when mixed with serum from patients with leptospirosis and two other infectious diseases. The test, which can be completed within 3 min has been used to assay over 1200 patient samples.

Cutaneous abscess caused by Nocardia brasiliensis: report of a case

We report a case of cutaneous Nocardia brasiliensis infection. The patient had received radiotherapy and anti-neoplastic chemotherapy for epidermoid carcinoma of the left sphenoid sinus with bone destruction. He developed fever and an ulcer on the dorsal medial surface of the left hand after an intravenous infusion of chemotherapeutic agents in the same site 3 days earlier. Needle aspiration of the abscess disclosed polymorphonuclear leukocytes, and a partially acid-fast, gram-positive filamentous branching organism. Cultures of the aspirate grew N. brasiliensis 1 week later. The patient was treated successfully with a regimen of parenteral ceftazidime and amikacin with definite improvement 1 week later. Therapy was continued for 1 more week, and then the patient was switched to oral trimethoprim-sulfamethoxazole for 3 months with no recurrence. The diagnosis, clinical manifestations, treatment and prognosis of cutaneous abscesses cause by N. brasiliensis are discussed.

Carbon-13 nuclear magnetic resonance assignments and spectral characteristics for some pavine alkaloids

Detailed 13C-NMR spectral assignments were made for some pavine alkaloids isolated from Cryptocarya chinensis, including (-)-crychine (1), (-)-caryachine (2), and (+)-O-methylcaryachine (3), and neocaryachine (4). The assignments were based on detailed analysis of 1H NMR, 13C NMR, heteronuclear 1H-13C COSY, both one-bond and long-range correlations, and cross comparisons with model compounds. Substituent effects on the chemical shifts of the N-methylpavinane skeleton were analyzed in view of their utility in structural elucidation.

Legionnaires' disease following cardiac transplantation

One case of Legionnaires' disease in cardiac transplant recipient is reported. She was diagnosed by immunofluorescence study of bronchoscopic lavage specimen and was treated by oral erythromycin successfully. The main presentations are fever and single pulmonary nodule with rapid progression and cavitation. In the literatures report, two complicated Legionnaires' disease was reported in cardiac transplant recipient. This case is less complicated than reported and is the first case in this country.

Cytomegalovirus interstitial pneumonitis in a bone marrow transplant recipient

A 15-year-old girl suffering from acute lymphoblastic leukemia developed cytomegalovirus interstitial pneumonitis 34 days after an allogenic bone marrow transplantation. The disease was diagnosed by open lung biopsy. Histopathologic examination disclosed intranuclear and intracytoplasmic inclusion bodies, as well as, a positive cytomegalovirus antigen detected by an immunofluorescence stain using a cytomegalovirus monoclonal antibody. The virus culture also eventually produced cytomegalovirus. Because of the lack of ganciclovir in this country, antiviral therapy of a non-specific nature was given to this patient. However, the treatment was ineffective and she subsequently died. There is an association between the immunologic events of a graft-versus-host disease and the development of cytomegalovirus interstitial pneumonitis. The pathogenesis of cytomegalovirus interstitial pneumonitis in a bone marrow transplant recipient is evidence of an immunopathologic disease, rather than that of a purely infectionus disease. years, the treatment modality of cytomegalovirus interstitial pneumonitis in bone marrow transplant recipients has become a combination of specific antiviral and immune therapy.

Causal bacteria of pyogenic liver abscess

This is a review of bacteriologic data on 175 patients with pyogenic liver abscesses seen over a period of 8 years at Veterans General Hospital, Taipei, Taiwan. Positive cultures were obtained from liver aspirates in 151 of the 163 patients in which cultures were taken. One hundred and twenty patient specimens grew one isolate and 31 specimens grew two or more isolates. A total of 149 aerobic gram-negative rods, 25 aerobic cocci and 29 anaerobes were isolated. Ninety of the 159 patients from whom blood was taken had positive cultures. In 11 patients, two or more isolates were grown concurrently from the blood. A total of 87 aerobic gram-negative rods, 7 aerobic cocci and 10 anaerobes were isolated. Klebsiella pneumoniae was the most common microorganism, accounting for 50.8% of the cases. Other major pathogens were Escherichia coli (27.4%), anaerobes (15.4%), and viridans streptococci (6.2%).

Acute effects of fever, fasting and aspirin on infant rat gastric mucosa

Clinical experience shows that young children with gastrointestinal bleeding have frequently had some preceding febrile illness for which aspirin was administered. Febrile young children often have poor food or liquid intake, or have been in a fasting state because of diarrhea, vomiting or anorexia. The objective of this study was to determine the acute effects of fever, fasting and oral aspirin administration on the gastrointestinal mucosa. One hundred and sixty-eight infant rats, from 21 to 28 days of age and weighting from 70 to 120 g were studied. Random assignment was made to eight groups (Grs): Control (Gr I); aspirin administration only (Gr II); fasting only (Gr III); fever only (Gr IV); aspirin and fever (Gr V); fasting and fever (Gr VI); aspirin and fasting (Gr VII); and aspirin, fever and fasting (Gr VIII). Aspirin was given orally in a single daily dose of 200 mg/kg for two days. Fever was induced by an intraperitoneal injection of 0.6 ml salmonella vaccine. Fasting time lasted from 40 to 48 hours (8 hours prior to the beginning of the experiment to the end of study). The severity of the gastric bleeding was estimated by scoring the number of petechiae and the percentage of the hemorrhagic erosion area from grade 0 to 3. Results showed that rats in Grs VII and VIII had significantly more severe grades of petechiae and hemorrhage than the other groups. These were the groups where the risk factors of fasting and aspirin administration coexisted. In addition to fasting, Gr VIII had fever, but this group did not show more gastric mucosal damage than Gr VII showed.(ABSTRACT TRUNCATED AT 250 WORDS)

Dephosphorylation of neuromodulin by calcineurin

Neuromodulin (p57, GAP-43, F1, B-50) is a major neural-specific, calmodulin binding protein found in brain, spinal cord, and retina that is associated with membranes. Phosphorylation of neuromodulin by protein kinase C causes a significant reduction in its affinity for calmodulin (Alexander, K. A., Cimler, B. M., Meirer, K. E., and Storm, D. R. (1987) J. Biol. Chem. 262, 6108-6113). It has been proposed that neuromodulin may function to bind and concentrate calmodulin at specific sites within neurons and that activation of protein kinase C causes the release of free calmodulin at high concentrations near its target proteins. It was the goal of this study to determine whether bovine brain contains a phosphoprotein phosphatase that will utilize phosphoneuromodulin as a substrate. Phosphatase activity for phosphoneuromodulin was partially purified from a bovine brain extract using DEAE-Sephacel and Sephacryl S-200 gel filtration chromatography. The neuromodulin phosphatase activity was resolved into two peaks by Affi-Gel Blue chromatography. One of these phosphatases, which represented approximately 60% of the total neuromodulin phosphatase activity, was tentatively identified as calcineurin by its requirement for Ca2+ and calmodulin (CaM) and inhibition of its activity by chlorpromazine. Therefore, bovine brain calcineurin was purified to homogeneity and examined for its phosphatase activity against bovine phosphoneuromodulin. Calcineurin rapidly dephosphorylated phosphoneuromodulin in the presence of micromolar Ca2+ and 3 microM CaM. The apparent Km and Vmax for the dephosphorylation of neuromodulin, measured in the presence of micromolar Ca2+ and 2 microM CaM, were 2.5 microM and 70 nmol Pi/mg/min, respectively, compared to a Km and Vmax of 4 microM and 55 nmol Pi/mg/min, respectively, for myosin light chain under the same conditions. Dephosphorylation of neuromodulin by calcineurin was stimulated 50-fold by calmodulin in the presence of micromolar free Ca2+. Half-maximal stimulation was observed at a calmodulin concentration of 0.5 microM. We propose that phosphoneuromodulin may be a physiologically important substrate for calcineurin and that calcineurin and protein kinase C may regulate the levels of free calmodulin available in neurons.

Studies on bio-antioxidants--micellar effects on the reduction of nitroxides by vitamin C

The kinetics of reduction of nitroxides including 4-hydroxy-TEMPO, 4-methoxy-TEMPO and 4-hexanoyloxy-TEMPO, which are of different lipophilicities, by vitamin C in cationic, non-ionic and anionic micelles, i.e. CTAB, Triton X-100 and SDS, respectively, have been studied by FSR spectroscopy by a stopped-flow technique. A mechanism for the reaction conducted in micelles is proposed and the rate constants for the elementary reactions are evaluated. It is found that the rates of single electron transfer reactions involving the nitroxides are dependent on the nature of the micelle and the lipophilicity of the nitroxide. The rates are increased in CTAB, decreased in SDS, whereas unaffected in Triton X-100. And the greater the lipophilicity of the nitroxide, the more pronounced the rate variation. As high as a 3600-fold increase in the rate was observed for 4-hexanoyloxy-TEMPO in CTAB over that in SDS. The micellar effects are rationalized on the basis of analysis of parameters and line shape of the ESR spectra for the nitroxides in the micelles.

Gene expression of PCNA/cyclin in adult tissues and the R3230AC mammary tumor of rat

We have investigated the gene expression of PCNA (Proliferating Cell Nuclear Antigen)/cyclin in rat tissues and the R3230AC mammary tumor. The steady-state mRNA level of PCNA/cyclin in a tissue is related to the proliferation of the tissue. The observation was confirmed with the results from the studies of the immunoblotting analyses and the DNA polymerase activity measurements. Furthermore, an overexpression of PCNA/cyclin was found in the R3230AC mammary tumor, which is accompanied by an altered PCNA/cyclin gene structure detected with the Southern blot analysis.

[Electrophysiologic effects of sophocarpine on papillary muscle in guinea pig]

Sophocarpine prolonged the action potential duration of guinea pig papillary muscle in a dose-dependent manner. After the preparations were exposed to sophocarpine 50 mumol/L for 30 min, APD50 and APD90 were prolonged from 189 +/- 21 and 216 +/- 24 ms to 205 +/- 27 and 241 +/- 25 ms (P less than 0.01). Simultaneously, ERP was prolonged from 202 +/- 14 to 211 +/- 16 ms, although the ERP/APD90 ratio was not changed. Sophocarpine had no significant effects on other AP parameters. Propranolol did not block sophocarpine effects.

Necrotizing Pneumocystis carinii vasculitis associated with lung necrosis and cavitation in a patient with acquired immunodeficiency syndrome

Pulmonary cavitation is an infrequent manifestation of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome. The pathogenesis of lung cavities associated with P carinii pneumonia has not been fully elucidated by detailed morphologic studies. This article describes a patient with the acquired immunodeficiency syndrome and P carinii pneumonia who developed roentgenographically identified lung cavitation while being treated with azidothymidine. At autopsy, necrotizing vasculitis with vascular infiltration by Pneumocystis organisms was associated with lung necrosis and cavitation. No other causes of pulmonary cavitation were identified. Thus, in patients with acquired immunodeficiency syndrome, P carinii, per se, may result in lung necrosis and cavitation, possibly through the mechanism of necrotizing angiitis.

Requirement for proliferating cell nuclear antigen expression during stages of the Chinese hamster ovary cell cycle

Proliferating cell nuclear antigen (PCNA/cyclin) is a nuclear protein that can stimulate purified DNA polymerase delta in vitro, and its synthesis correlates with the proliferation rate of cells. We have attempted to determine whether synthesis of PCNA/cyclin in Chinese hamster ovary cells is necessary to regulate entry into S phase. We have measured cellular PCNA/cyclin concentration of the mRNA or protein throughout the cell cycle. Cells were separated by centrifugal elutriation into populations enriched for G-1, S, and G-2/M phases. Quantitative Northern hybridization analysis was performed on RNA isolated from each cell population by using a cDNA clone of PCNA/cyclin as a probe. Results demonstrated that although intact PCNA/cyclin mRNA is present during all phases of the cell cycle, an induction of about 3-fold occurs during S phase. Two-parameter staining for PCNA/cyclin and DNA, and analysis by flow cytometry, confirmed that the quantity of PCNA/cyclin protein in the cells increases severalfold in G-1 or early S phase but generally is invariant in S and G-2/M phases. This cell cycle dependence of PCNA/cyclin expression suggests that the observed synthesis is a prerequisite for initiation of DNA replication. Introduction of an antisense oligonucleotide complementary to the PCNA/cyclin mRNA to inhibit PCNA/cyclin synthesis effectively prevented entry of G-1 phase cells into S phase. A complementary sense oligonucleotide used as a control did not have an inhibitory effect. This result suggests that a threshold concentration of PCNA/cyclin is necessary for entry into S phase.

[Renal vein thrombosis in nephrotic syndrome--a prospective study of 54 cases]

Recent advance of radiographic technique makes antemortem diagnosis of renal vein thrombosis (RVT) possible. However the incidence of RVT in patients with nephrotic syndrome(NS) is still not known. This study was designed to investigate the incidence, clinical presentation and radiological features of RVT in NS patients in China. A prospective study including clinical, and pathological examination as well as renal venogram was carried out in all our hospitalized NS patients except those having contradiction for renal venogram. RVT was found in 23 of the 54 cases (42%) and there was obstruction in 34 renal vein branches. RVT was more common in left (19) than right side (15), in upper (19) than middle and lower branches (10). It is interesting that in our group not only membranous but also minimal change as well as mesangium proliferative glomerulonephritis had high incidence of RVT (47%, 45% and 36% respectively) Only 6 cases (26%) had a typical acute presentation with severe loin pain, significant increase of urinary protein, enlargement of involved kidney. Occasionally fever, deterioration of renal function and sterile urinary white cells were also present. The remaining patients (74%) had latent onset of RVT which could hardly be identified in the clinical course of the underlying NS. For the high incidence and atypical clinical course of RVT shown in our study, it is recommended that due attention should be paid of this complication during management of NS and interpretation of therapeutic response.

Pre- and post-operative hypothalamic-pituitary-thyroidal axis function in patients with prolactinoma, growth hormone tumour and ACTH tumour

Pre- and postoperative hypothalamic-pituitary-thyroid axis function was studied in 38 patients with pituitary adenomas (PRL, GH and ACTH tumours), of whom 35 were surgically confirmed and three diagnosed by clinical signs, CT scanning and hormone assessments. About ten days after operation, the same study was repeated in 10 patients with prolactinoma and 7 with growth hormone (GH) tumour. The preoperative abnormal serum TSH response to TRH was found in 8/20 patients with prolactinoma, 9/16 with GH tumour, and 2/2 with Cushing's disease due to ACTH microadenoma. The incidence of abnormal TSH response to TRH was not significantly increased in patients with larger adenoma in either PRL or GH tumour group. In 8 cases of prolactinoma, metoclopramide (MCP, 10 mg, P.O.) test was also performed and there was a significant positive correlation between TSH responses to TRH and to MCP. Serum TT3 in the GH tumour group was within normal ranges, but significantly higher than that of the normal and prolactinoma groups. After operation, TT3 was significantly decreased as compared with that before operation and there were marked changes in TSH response to TRH. In conclusion, there were some abnormalities in TSH control in patients with non-TSH pituitary tumour, and in serum TT3 control in patients with GH tumour. The surgical treatment of pituitary adenoma can lead to transient decrease in TSH reserve and serum TT3 level probably resulting from both stress and/or destruction of thyro-trophs by the operation.

The effects of the upright position during childbirth

The purpose of this investigation was to replicate an earlier study to clarify and verify its findings. The 68, term primigravidae married women between the ages of 18 and 25 years were assigned to three groups: (a) one group used a 30 degree upright position with no bearing down instructions during the second stage of labor (n = 24); (b) the second group used a 30 degree upright position with bearing down instructions given during the second stage of labor (n = 22); and (c) a control group used a zero degree recumbent position with bearing down instructions during the second stage of labor (n = 22). The upright position enhanced the descent of the fetal head with a shorter duration of labor in both the first and second stages. When mothers in an upright position were left alone to bear down in response to their own bodies' urges, the second stage of labor was of shorter duration.

Successful treatment of metastatic endophthalmitis. Case reports

Endophthalmitis is a well-recognized complication of intraocular surgery, penetrating ocular trauma and systemic infection. Metastatic bacterial endophthalmitis is rare. However, once it happens, the visual outcome is very poor. In order to prevent visual damage, early diagnosis and treatment is essential. Due to the blood-ocular barrier, intravitreal drug concentrations are low after systemic administration. Strong antibiotics with good penetration into the vitrous humor are needed to obtain adequate bactericidal concentrations. We report two cases with liver abscess complicated by septic events to the eye. One was uveitis, and the other was endophthalmitis. They were diagnosed early and were successfully treated with parenteral ceftriaxone and good vision was preserved.

Localization of fibronectin in the folliculo-stellate cells of the rat anterior pituitary by the double bridge peroxidase-antiperoxidase method

The localization of fibronectin was demonstrated in the rat anterior pituitary by the highly sensitive double bridge peroxidase-antiperoxidase (PAP) method. The fibronectin immunopositive cells were characterized by stellate-like morphology. The cells immunostained for fibronectin were observed to be identical to those for S-100 protein in adjacent mirror sections, whereas the S-100 protein has been specifically immunodetected in the folliculo-stellate (FS) cells of the anterior pituitary. The present study indicates that the fibronectin is present in the FS cells, suggesting that FS cells might play a role in the regulation of pituitary function through the interaction of fibronectin with hormone secreting cells.

Characterization of the genome of a vaccine strain of canine adenovirus type 1

Restriction endonuclease cleavage maps have been constructed for the genome of a canine adenovirus type 1 (CAV-1) vaccine strain (CLL; Connaught Laboratories, Ltd., Willowdale, Ontario). Restriction enzyme analyses were also carried out on CAV-1 (CLL) genomes isolated from viral stocks over 8 serial passages in a dog kidney cell line (DK 6722). The right hand 20% of the genome became more heterogeneous in size with increasing passage in DK 6722 cells due to deletions up to 3-4 kb, whereas the left terminal region was stable throughout these passages. A comparative study of CAV-1(CLL) and a virulent strain of CAV-1, Glaxo, revealed that the genome of CAV-1(CLL) was the shorter, by about 480 bp, within the region covering 0.83-0.91 map units. By virtue of its location within the genome and its dispensable nature for viral growth, this region would appear to encompass a genetic sequence corresponding to the E3 region of human adenoviruses. In terms of viral attenuation, the possible importance of the observed differences between CAV-1(CLL) and CAV-1(Glaxo) is discussed.

Co-localization of LH beta and FSH beta mRNAS in the porcine anterior pituitary by in situ hybridization with biotinylated probes

The localizations of mRNAs encoding LH beta and FSH beta in porcine pituitary were investigated by in situ hybridization technique. Biotinylated porcine LH beta and FSH beta cDNA probes were used on frozen sections of paraformaldehyde-fixed pituitary specimens. Hybridizations to both mRNAs were observed specifically in cytoplasm with unstained nuclei. Furthermore, cells hybridized for LH beta mRNA were demonstrated to be identical to those for FSH beta mRNA. This study provided the first morphological evidence that both gonadotropin beta genes are expressed in the same cell.

Multiple reiteration of a 40-bp nucleotide sequence in the inverted terminal repeat of the genome of a canine adenovirus

The DNA of a vaccine strain of canine adenovirus type 1 [ICHV vaccine; Connaught Laboratories, Ltd.; CAV-1(CLL)] has been cloned in plasmid pAT153 in the form of subgenomic BamHI digestion fragments. Analysis of the nucleotide sequences of cloned terminal fragments has revealed an inverted terminal repeat (ITR) with a minimum length of 198 nucleotides, including a tandem reiteration of the 40-bp nucleotide sequence from positions 14 to 53. The ITRs had the 5'-CATCATCAAT ... sequence typical of adenoviruses and the highly conserved sequence ATAATATAC (nucleotides 9-17) of human strains. Additionally, one BamHI A clone (left terminus) contained three sequential copies of the 40-bp sequence, and two BamHI C clones (right terminus) contained at least seven. These did not appear to be artifacts of cloning, since evidence was obtained that the multiple reiterations also occurred in DNA isolated from intact virus. By analogy with human adenoviruses, the repetitive sequence in the CAV-1(CLL) genome encompasses the entire nuclear factor I (NFI) binding site of the origin of DNA replication. Additionally, the 40-bp nucleotide sequence was found to contain the sequence AGG(N)4GCCTAA (nucleotides 27-39), which closely resembles the concensus sequence of the human adenovirus NFI binding site [TGG(N)6-7GCCAA; nucleotides 25-38]. It appears, therefore, that the Connaught CAV-1 vaccine contains reiterated copies of an essential part of the adenoviral origin of DNA replication. A mechanism is proposed for the generation of multiple reiterations of sequences in the right ITR, given an initial single tandem repeat in the left ITR.

Accessibility and multivalency of immobilized Cibacron blue F3GA

The effect of immobilized dye concentration on protein complexation was observed using zonal chromatography. A monomeric protein, octopine dehydrogenase, was retained by a single interaction to a Sepharose CL-6B column containing 11.6 mM immobilized Cibacron blue F3GA. By contrast, a tetrameric protein, lactate dehydrogenase, was retained by the same column by multiple interactions. The degree of multiple interactions was found to systematically increase with increasing immobilized dye concentration. The concentration of immobilized dye accessible to protein was found to be inversely related to the concentration of ionic components in the solvent. Zonal chromatographic measurements of free dye and unconjugated matrix suggest that increasing the concentration of ionic components promotes the adsorption of immobilized dye to the adjacent matrix surface. Such adsorption markedly affects both the capacity of an immobilized dye column and the multiplicity of its interaction with oligomeric proteins.

Klebsiella pneumoniae liver abscess associated with septic endophthalmitis

Metastatic septic bacterial endophthalmitis is a rare, but devastating disease. We encountered seven cases of pyogenic liver abscess associated with septic endophthalmitis during a recent four-year period. The causative organism was a pure culture of Klebsiella pneumoniae. The diagnosis was made by results of a blood culture in seven of the cases, liver aspirate culture in four, and eye contents or conjunctival culture in four. Chest roentgenographic examination showed pulmonary embolization in four patients, purulent meningitis in one patient, and suspicious prostatic abscess in one patient. Despite diligent antibiotic therapy, six patients lost their vision and one had impaired vision. This poor outcome for septic endophthalmitis seems to result from delayed diagnosis and lack of scheduled periocular injections of antibiotics. A combination course of treatment by the internist and ophthalmologist acting aggressively, both diagnostically and therapeutically, is needed in the future. To have seven cases of K pneumoniae liver abscess complicated by septic endophthalmitis during a period of four years in one hospital is very unusual. To our knowledge, it has never been reported in the literature.

Zonal chromatographic analysis of the interaction of alcohol dehydrogenase with blue-sepharose

The interaction between horse liver alcohol dehydrogenase and Reactive blue 2 immobilized on Sepharose CL-6B was measured by zonal chromatography. Each protein molecule was retained by a single immobilized dye using a Blue-Sepharose column containing a total of 1.38 mM dye. However, the protein was predominantly retained by two immobilized dye molecules using a darker Blue-Sepharose column containing a total of 11.6 mM dye. The dissociation constant measured for the alcohol dehydrogenase--immobilized dye complex on each column is identical to the inhibition constant for the alcohol dehydrogenase--free Reactive blue 2 complex: 4.5 +/- 0.8 microM.

Nonmuscle tropomyosin from ascites tumor cell microvilli

Tropomyosin has been isolated from microvilli preparations from 13762 rat mammary adenocarcinoma ascites tumor cells by Triton extraction and pelleting of the microvillar microfilament core, extraction of the microfilament core with 1 M KCl, heat treatment, and hydroxyapatite chromatography. Three major isoforms, designated 31K-a (acidic), 31K-b (basic), and 29K, were identified as tropomyosins by two-dimensional isoelectric focusing-dodecyl sulfate electrophoresis, a urea shift on dodecyl sulfate electrophoresis, chemical cross-linking, amino acid analysis, and molecular weight determinations. The native (60,000) and subunit (31,000 and 29,000) molecular weights, the amino acid composition, and the stoichiometry for binding to F-actin (actin/tropomyosin, 6:1) were typical of nonmuscle tropomyosins. The amount of tropomyosin present in the microvilli preparations is sufficient to saturate about half of the microvillar F-actin. By two-dimensional isoelectric focusing-dodecyl sulfate electrophoresis, the 31K isoforms appeared similar to isoforms of normal rat kidney cells but the 29K isoform was apparently smaller than any normal rat kidney isoforms. All three isoforms bound to F-actin, but the 29K form bound most strongly. Its behavior was similar to that of muscle tropomyosin, exhibiting saturable binding as a function of both ionic strength and Mg2+ concentration. In contrast, the 31K isoforms bound more weakly and required higher concentrations of Mg2+ for binding than that required for saturation with 29K (4 mM). These results clearly indicate that nonmuscle tropomyosin isoforms from a single source and location (subplasmalemmal) in the cell can exhibit different properties.

China: traditional healing and contemporary medicine

This paper shows how the health professions must meet the demands posed by China's vast geographical area, her population problem, her increasing technological development and economic situation, by utilizing available health resources as well as manpower in order to fulfil 'the national guarantee--to serve the people'.

Quantitative analysis of protein: immobilized dye interaction

The interaction of rabbit muscle lactate dehydrogenase with reactive blue 2 immobilized on Sepharose CL-6B was quantitatively evaluated by analytical procedures using both frontal and zonal chromatography and also static equilibrium methodology. All three analytical procedures give a common result, namely (i) that each enzyme molecule is retained by a single immobilized dye molecule; (ii) that the immobilized dye binds to the protein at an NADH binding site with an affinity identical to that of the free dye; and (iii) that less than 2% of the immobilized dye is accessible to the enzyme. The very small fractional accessibility is not due to steric exclusion but likely is a result of adsorption of the immobilized dye to the matrix surface.

Shared idiotopes among monoclonal antibodies specific for A/PR/8/34 (H1N1) and X-31(H3N2) influenza viruses

A monoclonal antibody specific for the hemagglutinin (HA) of influenza A X-31 (H3N2) virus (X-31) was obtained during a fusion of spleen cells from a BALB/c mouse immunized with influenza A/PR/8/34 (H1N1) virus (PR8). This monoclonal antibody (Py206) shares crossreactive idiotopes expressed on several monoclonal antibodies specific for PR8 HA and X-31 HA as well as an individual idiotope shared with one monoclonal antibody specific for X-31 HA. The presence of shared idiotypy among antibodies of such diverse binding specificities may result from regulation by idiotype-specific T cells. In addition, the results suggest that, in contrast to the diversity of paratypes expressed, relatively few germ-line variable region genes may be used in the antibody response to influenza A virus antigens.