[Comparative study on cefmetazole and cefazolin in the treatment of suppurative otitis media]

Cefmetazole (CMZ) was compared to cefazolin (CEZ) for efficacy and safety in the treatment of suppurative otitis media (including acute otitis media and chronic otitis media in acute aggravating stage) under well controlled clinical trials. The therapeutic effects were analyzed statistically in 172 patients (82 administered CMZ, 90 administered CEZ). The adverse reactions were also analyzed statistically in 199 patients (CMZ 99, CEZ 100) in whom the judgement was possible. 1. The efficacy rate of CMZ (72.3% for good to excellent response) was assessed by physicians in charge to be similar to that of CEZ (59.3%). This was the same being assessed by the committee, too (CMZ 64.6%, CEZ 56.7%). 2. When patients were classified into 2 groups (acute otitis media, chronic otitis media in acute aggravating stage) with respect to diagnosis, statistically significant difference in clinical efficacy assessed by physicians in charge was observed in the cases with chronic otitis media (CMZ, CEZ). In addition, the improvements of flares on the drum membrane and the mucous membrane of eardrum were significantly better in the CMZ group than in the CEZ group. 3. Bacteriologically, 16 cases (19.8%) of S. aureus were resistant to CEZ, while only 1 case (1.2%) to CMZ. CMZ was judged to be effective in 5 of the 6 cases in which CEZ-resistant strains were detected. 4. Side effects were found in 2 cases (2.0%) treated with CMZ: one complained of retching and abdominal pain and the other developed skin eruption. On the other hand, only 1 case (1.0%) developed skin eruption in the CEZ group. These results suggest that CMZ is a new antibiotic agent which is highly valuable in the treatment of suppurative otitis media.

[Pharmacokinetics and clinical studies of cefmetazole in the otorhinolaryngological field]

Cefmetazole (CMZ), a new cephamycin preparation, has been investigated to give following results. 1) Pharmacokinetics: Serum and tonsil concentration of CMZ were determined by micropore method in humans. The mean concentrations in 5 cases about 30 minutes after administration of 0.5--1.0 g intravenously were 55.4 micrograms/ml in serum, 21.7 micrograms/g in tonsil. 2) CLINICAL STUDIES: Seventy-one patients with ear, nose and throat infections were treated with CMZ receiving 1 to 6 g per day intravenously (one shot and drip infusion). Thirty-eight of 70 patients were cured excellent, 19 were good, 8 were fair and 6 were failure and effective rate was 80.3%. Adverse reaction was observed in 4 cases. Three cases showed exanthema and 1 case showed fever elevation.

Studies on purothionin by chemical modifications

Purothionin from wheat flour was chemically modified by acetic or succinic anhydride under specific conditions. The complete modification of all amino groups of purothionin caused a large change in the net charge of the molecule, leading to the loss of the toxicity to mice and yeast. The sole tyrosyl residue in purothionin was nitrated by tetranitromethane at neutral pH or iodinated by the lactoperoxidase method. The nitro- and diiodo-derivatives of purothionin showed considerably reduced toxicity. Based on these modification studies we conclude that the positive charges of lysyl residues have an important role in the interaction with the negatively charged cell surface, and that the emergence of the toxicity of purothionin depends on a certain state of the tyrosyl residue.

Structure-function relationship of [2Fe-2S] ferredoxins and design of a model molecule

[2Fe-2S] ferredoxins isolated from various plants and algae comprise 93-99 amino acid residues and resemble each other not only in sequences, but also in physiological functions. One of them isolated from Spirulina platensis was subjected to X-ray analysis and its three dimensional structure is now known. [2Fe-2S] ferredoxins of a different type are found in halobacteria and comprise 128 amino acid residues. Both types of the [2Fe-2S] ferredoxins exhibit low redox potentials. By comparing the amino acid sequences of 28 [2Fe-2S] ferredoxins and the tertiary structure of S. platensis ferredoxin we predicted a common three-dimensional structure to the [2Fe-2S] ferredoxins and proposed a molecular surface area to be interacting with FNR. An artificial small molecule composed of 20 amino acid residues is designed on the basis of the tertiary structure of S. platensis ferredoxin. The amino acid sequence was predicted to be Pro-Tyr-Ser-Cys-Arg-Ala-Gly-Ala-Cys-Ser-Thr-Cys-Ala-Gyl-Pro-Leu-Leu-Thr Cys-Val which should have a [2Fe-2S] cluster with a low redox potential.

The second ferredoxin from spinach leaves

A minor component of ferredoxin (about 20% of the total content) was separated from the major one on a DEAE Trisacryl M column only after carboxymethylation of the ferredoxin purified from spinach leaves by the conventional procedure. The amino acid compositions and terminal sequences of the two revealed that the major component corresponded to the one previously sequenced (Matsubara, H. & Sasaki, M. (1968) J. Biol. Chem. 243, 1732-1757) and the minor one had a completely different structure from that of the major one. Comparison of the amino(N)-terminal 34 residues showed 11 amino acid substitutions between the two components. Thus the existence of a second ferredoxin was demonstrated in spinach leaves.

Experimental myocarditis. II. Cardiac lesions in rats induced by immunization with heterologous heart extracts

The production of myocardial lesions and circulating anti-heart antibodies has been studied in the present experiment. Twenty-one of Wistar rats were divided into 3 groups: 9 rats immunized with heterologous heart extracts, Freund's complete adjuvant and diphtheria-tetanus-pertussis (DTP) vaccine, 8 rats injected phosphate buffered saline adjuvant mixture with DTP vaccine and 4 rats untreated as control. Injection of heterologous heart extracts emulsified with Freund's complete adjuvant and DTP vaccine developed focal myocardial lesions in all of the subjected rats. The lesions were characterized by focal and diffuse interstitial cellular infiltration with myocardial necrosis. The circulating antibodies reacted to rat heart extracts were detected in 77.8% of the subjects. The antigen, reacted with the antibodies, located intracellular spaces in myocardium. The severity of cardiac lesions were not functional to the titer of circulating anti-heart antibodies may play little role in the pathogenesis of myocardial damage at least in this experimental myocarditis.

X-ray analysis of a [2Fe-2S] ferrodoxin from Spirulina platensis. Main chain fold and location of side chains at 2.5 A resolution

A [2Fe-2S] ferrodoxin from Spirulina platensis crystallized in space group C2221 with cell dimensions of a = 62.32, b = 28.51, c = 108.08 A, and alpha = beta = gamma = 90.0 degrees. X-ray structure analysis of the protein was carried out at 2.5 A resolution by the single isomorphous replacement method coupled with the derivative and the native anomalous dispersion methods. Phase angles of 2182 independent reflections were determined and their average figure of merit was 0.58. Each of 98 residues was superposed on the electron density sections enlarged to 2 cm/l A with a half-mirror device (Richards box). About 25% of the total residues form beta-structure and 10% fold in a tow-turn alpha-helix. A beta-barrel-like structure was found in the main chain fold. A polypeptide segment from residues 41 to 49 forms a loop structure outside the barrel. Two iron atoms of the [2Fe-2S] cluster are coordinated by three cysteines in the loop and by Cys-79. Hydrogen bonds of NH....S and OH....S stabilize the loop conformation. Most side chains are reasonably oriented in the molecule. The internal volume of the barrel is occupied by aliphatic nonpolar residues. All the charged groups are accessible to solvent molecules.

[Laboratory and clinical studies on ceftizoxime in otorhinolaryngological field (author's transl)]

From the laboratory and clinical studies on ceftizoxime (CZX), the following results were obtained 1) CZX was compared with cefazolin (CEZ) for in vitro activity against 6 standard strains and clinically isolated strains of Staphylococcus aureus (19 strains), Staphylococcus epidermidis (14), Proteus sp. (17), Escherichia coli (3), Klebsiella sp. (3) and Pseudomonas aeruginosa (13). While somewhat less active against Gram-positive cocci than CEZ, CZX was far more active than CEZ against Gram-negative bacilli. 2) The time course of mean serum CZX levels in 2 patients given a single intravenous dose of 10 mg/kg was as follows: 24.9 microgram/ml at 15 minutes, 18.5 microgram/ml at 30 minutes, 13.2 microgram/ml at 1 hour, 6.4 microgram/ml at 2 hours and 2.7 microgram/ml at 4 hours. The mean serum half life was 1.36 hours. The mean tonsil concentrations of CZX 30 minutes after a single intravenous dose of 0.5 g and 1.0 g were 5.9 microgram/g and 9.6 microgram/g. respectively, with the ratio to the serum concentration of 0.33 and 0.32. 3) CZX was given to 28 patients with ear, nose, and throat infections, and overall rate of effectiveness was 92.3%. No clinical side effects were observed. Changes in laboratory test findings included slightly elevated GOT and/or GPT in 3 cases.

Increased activity of a neutral protease in cytosol from rat hepatoma induced by N-2-fluorenylacetamide

A protease active with N-alpha-benzoyl-DL-arginine-p-nitroanilide with an optimum pH of 7.3 has been found in the cytosol of rat liver. The activity of this protease increased in N-2-fluorenylacetamide-induced hepatoma as well as in fetal liver. It has been purified from normal liver and hepatoma about 200-fold. Its molecular weight is estimated by gel filtration to be about 200,000 in each tissue. The protease activity is unaffected by chymostatin, pepstatin, soybean trypsin inhibitor, and p-chloromercuribenzoate. Antipain, leupeptin, tosyl-L-lysine chloromethyl ketone, and phenylmethylsulfonyl fluoride inhibit the protease activity. This protease appears to be a serine protease.

Studies on algal cytochromes II. Some physical and chemical properties of further purified Petalonia cytochrome c-553

A cytochrome c-553 was isolated from a brown alga, Petalonia fascia, and its physical and chemical properties were investigated. At liquid nitrogen temperature, the α-, β- and γ-band of this cytochrome shifted 1-2 nm to the shorter wavelength in comparison with those at room temperature. The α-band split into two peaks, 551.5 (major band) and 546.5 nm (minor band), at the low temperature. The cytochrome in high concentration showed a shoulder at 695 nm in its oxidized state, suggesting a methionine residue to be the sixth ligand of heme iron. The molecular weight was estimated to be about 10,000 containing one mole of heme c based on analyses of gel filtration, sodium dodecyl sulfate acrylamide gel electrophoresis, amino acid composition and iron content. The isoelectric points of the ferro- and ferricytochromes were estimated to be at pH 4.1 and 4.3, respectively, by the isoelectric focusing method. The amino acid composition of this cytochrome was Lys6, Arg1, Asp15, Thr5, Ser6, Glu11, Pro2, Gly7, Ala7, Cys2, Val6, Met3, Ile6, Leu3, Tyr1, Phe3, Trp1, with a total of 86 residues. The amino- and carboxylterminal sequences and four chymotryptic peptide sequences were compared with those of other cytochromes c to show that these cytochromes were homologous to one another.

Acetylcholine receptor in rabbit thymus: antigenic similarity between acetylcholine receptors of muscle and thymus

This study was performed to examine the presence and immunological properties of acetylcholine receptor (AChR) in rabbit thymus. Binding of 125I-alpha Bungarotoxin (alpha BGT) to Triton extract from rabbit thymus was saturable (half saturation value: 10 X 10(-9) M) and occurred with at least two affinities, a high one with a dissociation constant of 1.1 X 10(-10)M and a low affinity one with a dissociation constant of 2 X 10(-9)M. The complex formation of 125I-alpha BGT-thymus extract was inhibited by both carbamylcholine and D-tubocurarine. These results indicate the existence of AChR in rabbit thymus. Antibody to AChR which was purified from experimental myasthenic rabbits with Narke AChR-affinity gel and labelled with 125I was used to identify the receptor antigenicity in rabbit thymus. Specific binding of 125I-antibody to thymic extract was demonstrated by the DEAE-paper disc assay. It is concluded from these results that AChRs with a similar antigenicity to that of skeletal muscle AChR exist in rabbit thymus. Our findings obtained in this study will support a hypothesis that the primary immunogen in myasthenia gravis may be AChR in thymus and an autoimmune reaction against AChR might be initiated within the thymus gland itself.

Experimental myocarditis. I. Cardiac lesions in rats induced by immunization with homologous heart extracts

The production of myocardial lesions and circulating anti-heart antibodies has been studied in rats injected with homologous heart extracts emulsified with the Freund's complete adjuvant and the DTP vaccine. Six of 7 rats showed lesions of focal myocarditis, while only in one of them circulating anti-heart antibodies were detected. There was no correlation between the presence of circulating anti-heart antibodies and that of myocardial lesions. These findings suggested that the circulating anti-heart antibodies may play little or no role in the pathogenesis of this experimental myocarditis.

A protease from rat intestine

Partially purified ribonuclease H from rat liver nuclei can be inactivated by a soluble fraction from rat intestine; this inactivation is restored by adding trypsin inhibitor, suggesting that the factor is a protease. A preparation has been isolated and purified to homogeneity. The molecular weight of the enzyme was estimated as 28 000 with an optimum pH of 8.0 and an isoelectric point at pH 4.5--4.7. The inactivating and proteolytic activities were observed in parallel throughout the purification procedures. Diisopropylphosphorofluoridate inhibited the protease activity. The protease inactivates deoxyribonuclease I, pyruvate kinase, and aldolase. From experiments with protease modifiers, it seems to be a serine protease of a trypsin-like nature.