[Experimental investigation on non-specific foreign body sarcoma induction of Al2O3-ceramic implants (author's transl)].

This investigation presents experimental results on possible non-specific foreign body sarcoma induction by Al2O3-ceramic implants. Solid and porous discs, subcutaneously implanted in rats produce a sarcoma rate of 17.4 resp. 17.8 p.c. while roughly perforated discs initiate sarcomas at a rate of 25.4 p.c. These values were found to be lower than comparative values in the literature produced with different metals and medical grade plastics. Powdered alumina implants did not produce any sarcomas. Only this latter result can mainly be transferred into prognostic assumptions concerning the clinical application of Al2O3-ceramic. The results are discussed extensively in the lights of the existing literature, this indicating that the tested ceramic itself may not possess a significant sarcogenetic potency in humans.


[The technic of fibrin glue in cancellous bone transplants (author's transl)].

The paper deals with the clinical experience in the use of a biological adhesive system in conjunction with bone transplants to close large bone defects. The gluing technique has been exactly described, 11 patients with a follow-up between 9 and 21 months are being presented. The application of this system which consists of highly concentrated native fibronogen, thrombin, and clotting factor XIII results in an acceleration of homogenous incorporation of the implants. No deterioration of wound healing occurred. The advantages of this method are: exact local hemostasis, adhesive strength, and plasticity.


Floor of mouth reconstruction with free dorsalis pedis flap.

Inadequate function frequently follows extensive obliterative surgery in the oral cavity. Extra tissue will allow closure and reconstruction of the defect with improvement of oral competency. We describe a method wherein a free dorsalis pedis arterialized flap is used for closure of intraoral defects. This method has the following advantages: (1) The flap may be raised while the extirpative portion of the procedure is in progress. (2) There is no need for prior delays of the flap. (3) The skin of the dorsalis pedia area is thinner than that of other flap ares, allowing the flap to be twisted along several planes. (4) A second procedure is not needed to return the base of the "flap pedicle." (5) The time of operation was not found to be greater than that in cases in which a forehead or deltopectoral flap was used.


The potential of an educational computer in medical education.

The use of an educational computer for a medical course is reviewed. It is of value for assessment, small group teaching, self-instruction, and continuing medical education. It is particularly useful for patient management problems.


Calcium ion-dependent diacylglycerol accumulation in erythrocytes is associated with microvesiculation but not with efflux of potassium ions.

Erythrocytes from several different species were exposed to Ca2+ and the bivalent-cation ionophore A23187. The lipid composition, morphology and K+ permeability of the treated cells were investigated. Erythrocytes from human, rat, guinea pig and rabbit (a) showed an increased concentration of 1,2-diacyl-sn-glycerol and enhanced labelling of phosphatidate with 32P, (b) underwent echinocytosis and outward vesiculation, and (c) rapidly released much of their intracellular K+. Pig cells showed only the K+ loss, and ox and sheep (high-K+) cells showed none of these Ca2+-evoked effects. All of the cells underwent stomatocytosis and inward vesiculation when treated externally with Clostridium perfringens phospholipase C. These results support the idea that there is a correlation between the asymmetric insertion of diacylglycerol (or ceramide) into the membrane and the shape-changes leading to microvesiculation, but they indicate that Ca2+-triggered K+ efflux and diacylglycerol production are unrelated events. Erythrocytes of chicken and turkey showed no Ca2+-stimulated K+ efflux. They showed slight ionophore A23187-stimulated vesiculation, but this appeared to be associated with the appearance in the membrane of ceramide rather than of diacylglycerol. Phospholipase C treatment caused very similar changes in morphology and phosphatidate labelling to those seen in mammalian erythrocytes.


The effects of altered sterol composition on the mitochondrial adenine nucleotide transporter of Saccharomyces cerevisiae.

1. The membrane sterol composition of mitochondria of the ole-3 mutant of Saccharomyces cerevisiae was manipulated by growing the organism in the presence of Tween 80 (1%, W/V) plus defined supplements o- delta-aminolaevulinate. 2. Changes in mitochondrial sterol content induced considerable changes in the adenine nucleotide transporter. 3. As the sterol content was decreased, the affinity of the transporter for ATP did not alter significantly, but the rate of ATP uptake was greatly decreased, the total number of atractylate-sensitive binding sites diminished, and the proportion of high-affinity binding sites was decreased. 4. Since sterol depletion also uncouples oxidative phosphorylation [Astin & Haslam (1977) Biochem. J., 166, 287-298] and prevents the intramitochondrial generation of ATP, the decrease in the rate of ATP uptake by sterol-depleted mitochondria will cause a decrease in intramitochondrial ATP concentrations in vivo. This probably explains the inhibition of mitochondrial macromolecular synthesis that has previously been reported in lipid-depleted yeast mitochondria.


The effect of 1,4-diaminobutanone on the stability of ornithine decarboxylase from Aspergillus nidulans.

1,4-Diaminobutanone, a competitive inhibitor of ornithine decarboxylase in Aspergillus nidulans, is able to increase the half-life of this enzyme and thus stimulate an increase in its activity in vivo. It also protects ornithine decarboxylase against proteolysis by chymotrypsin in vitro.


Hexokinase and glucose-phosphoenolpyruvate phosphotransferase synthesis in Klebsiella aerogenes strains growing in continuous culture.

Considerable differences in steady-state hexokinase specific activity were found in 16 N.C.I.B. strains of Klebsiella aerogenes grown in identical conditions in glucose-limited chemostats. Strains of N.C.I.B. 8258 had no detectable activity, but its glucose-phosphoenolpyruvate phosphotransferase specific activity and that of the other strains were closely similar, and it is concluded that this phosphotransferase activity regulates the overall utilization of glucose, in which hexokinase plays no essential role. The hexokinase activity was subject to regulation by the availability of phosphorus, but this did not affect the glucose phosphotransferase activity. tlactose-grown organisms (including strain N.C.I.B. 8258) had no glucose phosphotransferase activity, but more than adequate hexokinase activity to phosphorylate the intracellularly liberated glucose.


Nitrogenase of Klebsiella pneumoniae. Distinction between proton-reducing and acetylene-reducing forms of the enzyme: effect of temperature and component protein ratio on substrate-reduction kinetics.

Non-linear rates of acetylene reduction and concomitant H2 evolution were observed for the nitrogenase of Klebsiella pneumoniae at 10 degrees C. A lag phase of 1-4 min, dependent on the ratio of Mo-Fe protein to Fe protein present, occurred before linear rates of acetylene reduction were achieved. A complementary burst phase for concomitant H2 evolution in the presence of acetylene was also observed. When the proton was the only reducible substrate present, linear rates of H2 evolution were observed. N2 was a poor substrate under these conditions. Similar lag and burst phases occurred at 30 degrees C, but only when a large molar excess of Mo-Fe protein with respect to Fe protein was present. The results at 10 degrees C show that the binding of acetylene to the enzyme stimulates electron flow, but that these electrons, which initially reduce protons, can only reduce acetylene after a lag phase that cannot be accommodated in the turnover time calculated under steady-state conditions.


Non-histone chromosomal proteins: their role in the regulation of histone-gene expression.

Histone-gene expression was studied during the cell cycle of continuously dividing HeLa S3 cells and after stimulation of confluent monolayers of WI-38 human diploid fibroblasts to proliferate. The presence of histone-mRNA sequences was assayed by hybridization to a 3H-labelled single-stranded DNA complementary to histone-mRNA molecules. In HeLa S3 cells histone mRNA sequences were found in the nucleus and associated with polyribosomes during S-phase, but not during G1-phase. Transcripts of S-phase chromatin contained histone-mRNA sequences, but those of G1-phase chromatin did not. Similarly, in WI-38 cells association of histone-mRNA sequences with polyribosomes and transcription of histone-mRNA sequences from chromatin parallel DNA replication. Taken together these results suggest that the regulation of histone-gene expression resides, at least in part, at the transcriptional level. Chromatin-reconstitution studies provide evidence that non-histone chromosomal proteins play a key role in activation of histone-gene transcription during the period of the cell cycle when DNA is replicated. Phosphate groups associated with the S-phase non-histone chromosomal proteins appear to be functionally involved in the control of histone-gene readout.


Injected amphibian oocytes: a living test tube for the study of eukaryotic gene transcription?

Somatic-cell nuclei injected in Xenopus laevis oocytes remain transcriptionally active for up to 4 weeks. The rate of RNA synthesis increases as the somatic-cell nuclei enlarge. The message activity of the RNA synthesized by the injected nuclei can be demonstrated, as new proteins are made a few days after injection of HeLa-cell nuclei. Several lines of evidence demonstrate that these proteins are coded for by the HeLa-cell genome and that they result from RNA synthesized within the oocytes in the course of several days. Furthermore gene expression by the somatic-cell nuclei is selective, since only a few gene products can be detected. The oocyte cytoplasm is able to reprogramme the injected nuclei in such a way that only genes of the type normally active in oocytes are expressed. We describe experiments which indicate that genes previously inactive in the somatic cells can be switched on by the oocyte cytoplasm. These experiments have involved the use of the frog somatic-cell nuclei injected into newt oocytes. In addition, we have also found that even purified DNA is transcribed when injected into the nucleus of Xenopus oocytes. The identification of the molecules presumed to regulate chromatin transcription has been hampered by the lack of a satisfactory experimental system for assaying the biological activity of purified macromolecules. Living oocytes injected with somatic-cell nuclei (or cloned DNA) may provide such a system, since these regulatory factors could be introduced by a second injection.


Mitosis and microtuble assembly.

Microtubules reconstituted in vitro are identical in helical structure with tubules making up the mitotic spindle and both are formed by a helical condensation-polymerization mechanism. The protomer of microtubules is a heterodimer (alphabeta), of mol.wt. 110000 and sedimentation coefficient, SO25,w, 6S. This dimer has one binding site for colchicine or podophyllotoxin, two sites for Vinca alkaloids, two sites for guanine nucleotides and Ca2+-binding sites. There is also a beta-chain phosphoserine. Modulation of these properties is discussed as a possible way of regulating the competence of tubulin to polymerize. Reconstituted microtubules depolymerize to a mixture of 30-36S oligomeric tubulin and 6S dimer molecules. The 30-36S tubulin appears as a ring or disc when made visible in the electron microscope by negative staining. Three pathways of microtubule assembly have been proposed involving this ring as an intermediate: (1) the uncoiling of these rings into protofilaments; (2) the stacking of rings into macrotubules; (3) the rings as a scaffold for the assembly of a short segment of microtubule helix. Finally, the regulation of mitosis is discussed in terms of recent studies of tubulin and its polymerization, and studies in vitro and in vivo of the process of mitotic-spindle formation and disassembly.


The deoxyribonucleic acid polymerases of non-vertebrate eukaryotes.

DNA-dependent DNA polymerases have now been purified from a number of invertebrate animals, protists, higher plants and fungi. In this article we review the properties of these enzymes and compare them with the better-known enzymes of vertebrate animals and prokaryotes. Three facts emerge. Firstly, plants, protists and fungi contain high-molecular-weight DNA polymerases which may be capable of categorization into two groups on the basis of their properties in vitro. Secondly, no enzyme analogous to the vertebrate polymerase-beta has yet been found in such organisms, and thirdly, many of these enzymes possess associated exonuclease activities like those of the bacterial DNA polymerases. On the basis of these findings, some tentative proposals are made about the evolution of DNA polymerases.


Eukaryotic deoxyribonucleic acid-dependent ribonucleic acid polymerases: a critical assessment of current ideas concerning their multiplicity, specificity and function and their role in the regulation of gene expression.

Two comprehensive reviews of the eukaryotic DNA-dependent RNA polymerases have appeared in recent years (Chambon, 1974, 1975). It would be difficult to justify a further survey of this area within so short a period unless it was felt that this subject might benefit from a review having a rather different emphasis. We have taken a hard look at three broad areas of the subject which directly involve the RNA polymerases: (i) the definition of multiple RNA polymerases; (ii) information concerning their specificity and function, and (iii) putative direct involvement of the polymerases in the control of gene expression. Some original data are included, but for the most part a critical analysis is presented of such information as is available and the dogma which has become established in this difficult area of research.


An approach to the understanding of messenger ribonucleic acid synthesis, processing and regulation in eukaryotes.

Eukaryotic mRNA isolation is now relatively simple, and molecular probes allow analysis of gene number and specific gene expression by nucleic acid hybridization. Compelling evidence is accumulating for high-molecular-weight nuclear precursors of mRNA species, but little is known of their processing or detailed molecular structure. This should become clear when heterogeneous nuclear RNA molecules containing only one mRNA sequence are analysed.


Drug resistance and plasmid mediated transfer of drug resistance in Escherichia coli isolated from various districts of the human organism. A possible relationship with the antimicrobial drug concentrations during therapy.

The study of the prevalence of drug resistances and of the frequency of R factors among resistant strains, in E. coli isolated respectively from the respiratory, intestinal and urinary tracts of patients, during 1976, has shown that the frequency of drug resistances is highest among E. coli strains isolated from the respiratory tract and lowest among the E. coli strains isolated from urines. The frequency of R factors, among resistant strains, follows an exactly opposite distribution. This behaviour could be related to the gradient of antimicrobial drug concentrations achieved in the various compartments during ordinary antimicrobial therapy.


[Purification and standardization of commercial fluorescein-containing antiserums].

A method for the improvement of commercial antisera that consist of ammonium sulfate precipitated gamma-globulins labelled with fluorescein isothiocyanate, is presented. By a simple desalting on Sephadex G25 followed by a DEAE-cellulose stepwise chromatography, it is easy to recover only the fluoresceinated immunoglobulins of optimal fluorescein/protein ratio. The aspecificities due to the other fluoresceinated (mainly albumin) and also to the hypo- and hyper-conjugated gamma-globulins are then avoided. Even if eventual defects as regards the intrinsic characteristics of the antisera are not modified by this process, the improvement obtained is stringent and particularly evident in the indirect immunofluorescent staining of tissue sections. In consideration of the excellent quantitative recovery, this simple procedure is recommended to people that use commercial reagents for studies that are beyond the qualitative limits of routine diagnostic immunofluorescent tests.


[Urinary excresion of indican during recovery from malnutrition].

Most indican excreted in the urine comes from the degradation of tryptophan through the action of microorganisms dwelling within the intestinal lumen. Based on this  knowledge, the excretion of this compound was investigated during the recovery process of 19 malnourished infants; thus, attempts were made to recognize indirectly whether quantitative modifications take place in the intestinal flora as the state of nutrition is re-established. The results do not suggest the presence of an important variation of the bacterial content within the intestine of these children, at least during the first four weeks of their recovery.


[Current concepts on mucoviscidosis. Report of 2 cases].

The main aspects of the genetic cystic fibrosis, are reviewed; they are: incidence, pathophysiology, clinical signs and symptoms, treatment and prognosis. Emphasis is made on the infrequency of the diagnosis in Latin America. The pediatrician's attention is called in order to think in this possible diagnosis in cases of chronic pneumopathy with or without signs of poor intestinal absorption.


Comparison of atenolol and oxprenolol in patients with angina or hypertension and co-existent chronic airways obstruction.

1 The effects of atenolol (50 mg and 100 mg) and oxprenolol (80 mg) on respiratory function were studied in ten patients with angina pectoris or hypertension complicated by chronic airways obstruction. 2 In patients with "fixed" airways obstruction, neither atenolol nor exprenolol significantly affected airways resistance. 3 In patients with "labile" airways obstruction, atenolol did not produce a significant increase in airways obstruction, whereas oxprenolol did. 4 Following isoprenaline challenge (1500 microgram by inhalation), atenolol permitted full bronchodilatation, whereas oxprenolol almost completely blocked the action of isoprenaline. 5 Partial agonist activity appears to be of less clinical importance than cardioselectivity.


The effects of atenolol and propranolol upon lipolysis.

1 The effects of selective and non-selective beta-adrenoceptor blockade upon plasma non-esterified fatty acid concentrations in the fasting state and following insulin stress have been studied in normal subjects. 2 Atenolol, propranolol and placebo were compared in a double-blind cross-over trial in eight normal subjects. 3 Atenolol and propranolol significantly lowered plasma non-esterified fatty acid concentrations by a similar degree in the fasting, non-stressed state. This finding suggests that beta1-adrenoceptors are involved in the control of basal lipolysis. 4 Following insulin-induced stress, lower plasma non-esterified fatty acid concentrations were observed with propranolol than with atenolol. This difference may be due to beta2-adrenoceptor involvement in the stress mechanisms controlling lipolysis, or to the differences in the water-lipid solubility properties of these drugs.


The metabolic effects of inhaled salbutamol.

1 The metabolic effects of salbutamol (5 mg) given by intermittent positive pressure breathing have been studied in eight patients with airflow obstruction. 2 No changes in plasma nonesterified fatty acids, triglyceride, glucose, insulin or cortisol were seen 1 and 4 h after administration. 3 It is concluded that inhaled salbutamol does not cause the unwanted metabolic effects reported with oral or parenteral administration, and that this is a further indication for this route of administration.


Amitriptyline- and mianserin-induced changes in acquisition of paired-association learning-task.

1 The double-blind study on twenty healthy students was an attempt at assessing the effects of 2-week's treatment with amitriptyline (25 mg three times a day) and mianserin (10 mg three times a day), each alone or separatively inbibed with alcohol (0.5 g/kg) on the immediate memory and on the acquisition of a paired-association learning-task. 2 Amitriptyline impaired both the short-term memory-span and acquisition, and alcohol potentiated these effects. The action of mianserin did not deviate significantly from that of the placebo, and it also failed to interact with alcohol. 3 It is concluded that the decrement in learning capacity, that occurs after the 2-week's treatment with therapeutic doses of amitriptyline, reflects changes in both the intrinsic and the regulatory mechanisms of learning.


Non-immunological enhancement of tumour transplantability in x-irradiated host animals.

MSC-10 tumour cells (derived from a chemically induced pulmonary squamous-cell carcinoma in DBA/2 mice) were inoculated intramuscularly into thymectomized, X-irradiated isogeneic mice, either 48 h or 6 weeks after thymectomy and X-irradiation. Normal mice and immunologically reconstituted mice served as controls. A marked enhancement in frequency of tumour takes was observed in all groups of animals inoculated with tumour cells 48 h after whole:-body X-irradiation, whether thymectomized, immunologically reconstituted or not. The TD50 decreased to less than 1/10 of that observed in unirradiated controls. When mice were inoculated with tumour cells 6 weeks after X-irradiation, the incidence of tumour takes was similar to that of unirradiated controls, including the thymectomized-irradiated group, which was still severely immunodeficient as measured by antibody formation and skin graft rejection. The experiments indicate that whole-body X-irradiation creates a condition that favours tumour cell survival or growth. This "permissive state" exists only shortly after X-irradiation and is not correlated with the host's level of immunocompetence.


Analysis of heteroantisera to cells from human malignant effusions by immunofluorescence and protein A binding.

Using cultured cells derived from human malignant effusions, hetero-antisera were raised in rabbits. The antisera were sequentially absorbed on various human non-tumour cells, reactivity being monitored by immunofluorescence and 125I-labelled staphylococcal protein A assays. The absorbed antisera possessed common reactivity to all tumour cells assayed. This reactivity was not histogenically determined, and our data suggest that it was not directed to oncofoetal antigens.


Immunotherapy of acute myeloid leukaemia. Medical Research Council.

Seventy-one patients suffering from acute myeloid leukaemia (AML) who were already in complete remission and had already received one further course of cytotoxic drugs as consolidation therapy were randomised to receive maintenance chemotherapy alone or the same maintenance chemotherapy plus immunotherapy with BCG and irradiated allogeneic blast cells. The duration of first remission was slightly, but not significantly, longer in those patients who received immunotherapy. This was true also for the duration of survival after relapse. Comparison with other series suggested that the effect of such immunotherapy on duration of survival after relapse is probably real, but did not clearly indicate whether or not any real difference in the first remission duration existed.


Glial fibrillary acidic protein in tumours of the nervous system.

Glial fibrillary acidic protein (GFA) was assayed in nerve-tumour extracts and located in these tumours by indirect immunofluorescence study. We conclude that GFA is a specific marker of both malignant and normal astrocytes. Non-astrocytic tumours (oligodendroglioma, meningioma) do not contain GFA. Tumours with astrocytic differentiation potential (medulloblastoma) may contain GFA. Comparison of microscopic and GFA assays leads us to conclude that GFA concentration is proportional to the amount of malignant astrocytes in the tumour and inversely proportional to the necrotic area of a tumour. Normal tissue GFA and glioblastoma GFA were found to be immunologically identical.


The effect of partially replacing urea nitrogen with protein N on N capture in the rumen of sheep fed a purified diet.

1. The influence of replacing 10% of the urea nitrogen in a purified diet with casein, maize gluten or white fish meal on the efficiency of conversion of dietary-N into microbial N was examined using sheep equipped with rumen fistulas and duodenal re-entrant cannulas. 2. Total nitrogen (TN), non-ammonia nitrogen (NAN) and amino acid nitrogen (AAN) flowing to the proximal duodenum were significantly higher (P smaller than 0.05) when maize gluten was added to the diet, and this appeared to be due to an increased efficiency of microbial protein production. 3. Pepsin secretion was not significantly different between treatments and the daily amount of pepsin N flowing to the proximal duodenum was very small (40-53 mg). The peak of pepsin activity in duodenal digesta was reached 6-8 h after feeding. 4. The possible practical implications of the results are discussed.


Hydrolytically induced allosteric change in the heavy chain of intact myosin involving nonessential thiol groups.

The two globular head portions, each bearing an active site, contain an uncleaved heavy chain when isolated by chymotrypsin from intact myosin. By specific labeling with radioactive N-ethylmaleimide the essential thiol 1 and thiol 2 groups were found to reside in this heavy chain. In intact myosin nonessential thiol 3 groups become the most reactive during ATP hydrolysis above 15 degrees C. These thiol 3 groups are located in a portion of the myosin heavy chain which appears as a fragment with an apparent molecular weight of 11 000 during proteolysis. The facts that this fragment is produced in an almost 1: 1 molar ratio with the head heavy chain and that it bears unblocked N-terminal amino groups whereas the heavy chain does not and is not contained in the rod portion of the myosin molecule indicate that it may orginate from the heavy chains in the neck region where the heads are joined to the rod. Since this fragment is removed by ion-exchange chromatography, it is not part of the functioning head and hence not involved in the active site. As its nonessential thiol 3 groups are rendered the most reactive of all thiol groups in the enzyme-product complex M**ADP.Pi, the hydrolytic step induces an allosteric conformational change in the neck region of intact myosin.


Nucleotide sequences of accessible regions of 23S RNA in 50S ribosomal subunits.

Nucleotide sequences around kethoxal-reactive guanine residues of 23S RNA in 50S ribosomal subunits have been determined. By use of the diagonal paper electrophoresis method )Noller, H.F. (1974), Biochemistry 13, 4694-4703), 41 ribonuclease T1 oligonucleotides, originating from about 25 sites, were identified and sequenced. These sites are single stranded and accessible in free 50S subunits, and are thus potential sites for interaction with functional ligands during protein synthesis. Examination of these sequences for potential intermolecular base-pairing reveals the following: (1) There are 19 possible complementary combinations between exposed sequences in 16S and 23S RNA containing more than 4 base pairs: 15 containing 5 base pairs and 4 containing 6 base pairs. Nine of these complementary combinations contain 16S RNA sequences which we have previously shown to be protected from kethoxall by 50S subunits (Chapman, N.M., and Noller, H.F. (1977), J. Mol. Biol. 109, 131-149). (2) One of the exposed sites in 23S RNA has a sequence which is complementary to the invariant GT psi CR sequence in tRNA.


Saccharomyces cerevisiae DNA-dependent RNA polymerase III: a zinc metalloenzyme.

Yeast nuclear RNA polymerase III was purified by batch adsorption to phosphocellulose, followed by ion-exchange chromatography on DEAE-Sephadex and affinity chromatography on DNA-Sepharose. Polyacrylamide gel electrophoresis of the purified enzyme showed a single protein band which contained polymerase activity. The molecular weight estimated by sedimentation velocity centrifugation in a glycerol gradient was 380 000. Enzyme activity was inhibited 50% at 0.1 mM 1,10-phenanthroline and 100% of 1.0 mM, but was restored when 1,10-phenanthroline was removed by dialysis. Enzyme activity was not inhibited by 7,8-benzoquinoline, a nonchelating structural analogue of 1,10-phenanthroline. These results strongly suggest that inhibition of enzyme activity occurs by the formation of a reversible enzyme-zinc-phenanthroline ternary complex. The zinc content, measured by atomic absorption spectroscopy, was 2 g-atoms per mol of enzyme. Zinc was not removed from the enzyme by gel filtration on Sephadex G-25, by passage through Chelex-100 resin, or by dialysis against buffer containing 1,10-phenanthroline. Enzyme-bound zinc was removed by dialysis after denaturation of the enzyme with heat and sodium dodecyl sulfate. Enzyme-bound zinc did not exchange with free zinc. These results establish yeast nuclear RNA polymerase III as a zinc metalloenzyme.


Possible site-specific reagent for the general amino acid transport system of Saccharomyces cerevisiae.

The general amino acid transport system of Saccharomyces cerevisiae functions in the uptake of neutral, basic, and acidic amino acids. The amino acid analogue N-delta-chloroacetyl-L-ornithine (NCAO) has been tested as potential site specific reagent for this system. L-Tryptophan, which is transported exclusively by the general transport system, was used as a substrate. In the presence of glucose as an energy source, NCAO inhibited tryptophan transport competitively (Ki = 80 micrometer) during short time intervals (1-2 min), but adding 100 micrometer NCAO to a yeast cell suspension resulted in a time-dependent activation of tryptophan transport during the first 15 min of treatment. Following the activation a time-dependent decay of tryptophan transport activity occurred. Approximately 80% inactivation of the system was observed after 90 min. When a yeast cell suspension was treated with NCAO in the absence of an energy source, an 80% inactivation of tryptophan transport occurred in 90 min. The inactivation was noncompetitive (Ki congruent to 60 micrometer) and could not be reversed by the removal of the NCAO. Addition of a five-fold excess of L-lysine during NCAO treatment or prevented inactivation of tryptophan transport. Under parallel conditions of incubation, other closely related transport systems were not inhibited by NCAO.


Primary structure of Escherichia coli ribosomal protein L31.

Protein L31 from the 50S ribosomal subunit of Escherichia coli was manually sequenced by the dansyl-Edman method. Owing to the availability of only small quantities of purified L31, sequencing methods were scaled down such that the entire primary structure could be determined with 700 microgram of protein. The techniques employed are described in detail. The protein consists of a single chain of 62 amino acids, with a calculated molecular weight of 6967. Four half-cystine residues were identified at positions 16, 18, 37, and 40. Evidence is presented that suggests that these residues form two disulfide bridges in the protein, as isolated.


Primary structure of protein L19 from the large subunit of Escherichia coli ribosomes.

Protein L19, a component of the Escherichia coli 50S ribosomal subunit implicated in 30S-50S subunit interaction was sequenced by the dansyl-Edman method. L19 consists of a single polypeptide chain of 114 amino acids giving a calculated molecular weight of 13 002. Peptides obtained from various enzymatic cleavages were isolated on thin-layer peptide maps or gel filtration. Automated Edman degradation using a liquid phase sequenator was carried out on the whole protein as well as on a large 58-residue fragment arising from digestion with Staphylococcus aureus protease. Every position in protein L19 was confirmed at least twice. Results of secondary structure estimation and homologies with other E. coli ribosomal protein sequences are presented.


Isolation and partial purification of catfish pancreatic islet messenger RNA.

Poly(a)-rich mRNA has been isolated from catfish pancreatic islet total nucleic acid. Cell-free translation of the mRNA by wheat germ extracts yielded a protein of 11 000-12 000 molecular weight, estimated by sodium dodecyl sulfate-urea polyacrylamide gel electrophoresis. This peptide is larger than catfish proinsulin, but contains tryptic peptides of proinsulin. Its synthesis comprises up to 23% of the cell-free product, depending on the conditions of cell-free synthesis. Synthesis is inhibited by 7-methylguanosine 5'-monophosphate suggesting the presence of a 7-methylguanosine cap on the 5' end of catfish proinsulin mRNA. Sucrose gradient centrifugation of the islet poly(A)-rich mRNA yielded 8S and 12S peaks. These fractions were translated with wheat germ extracts and it was determined that over 60% of the islet mRNA-dependent protein from the 8S fraction was preproinsulin. The 8S mRNA fraction was electrophoresed on 3% agarose-6 M urea gels and demonstrated to be several bands, ranging from 100 000-200 000 molecular weight.


Changes in fluorescence of 8-anilino-1-naphthalene sulfonate after bacteriophage T5 infection of Escherichia coli. Initial fluorescence rise coincides with onset of rubidium efflux.

Escherichia coli cells pre-loaded with 86Rb+ begin to lose 86Rb+ immediately after phage T5 addition. The loss proceeds with negative-exponential (first-order) kinetics for up to approximately 15 min after phage addition. The constant which characterizes the rate of loss increases with increasing numbers of infecting phage per cell. It is known that anaerobic, fermenting cells of E. coli show a two-step increase in 8-anilino-1-naphthalene sulfonate (ANS) fluorescence upon infection with bacteriophage T5; the first rise begins immediately upon phage addition, the second 6 min later. The onset of 86Rb+ release, therefore, is correlated with the first fluorescence rise with respect to timing and response to the multiplicity of infection.


alpha-Glucosidase, a membrane-bound enzyme of alpha-glucan metabolism in Bacillus amyloliquefaciens. Purification and partial characterization.

The organism Bacillus amyloliquefaciens is capable of producing alpha-amylase (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1) and isoamylase (glycogen 6-glucanohydrolase, EC 3.2.1.68) extracellurlarly and a membrane-bound, intracellular alpha-glucosidase (alpha-D-glucoside glucohydrolase, EC 3.2.1.20). The amounts of alpha-glucosidase in cells of B. amyloliquefaciens grown on amylaceous polysaccharides were significantly higher then in cells grown on non-carbohydrate carbon sources. alpha-Glucosidase was exclusively found associated with membranes from ruptured spheroplasts by subcellular fractionation and solubilization studies. Salt solutions and chelating agents alone did not dislodge alpha-glucosidase from membranes, but in combination with detergents were most effective in solubilizing active enzyme (0.1% sodium cholate (pH 8.0)/0.4 M sodium chloride). Purified alpha-glucosidase very rapidly hydrolized p-nitrophenyl alpha-D-glucopyranoside and sucrose. Maltose, maltotriose, isomaltose and isomaltotriose were hydrolized at slower rates, whereas beta-glucosides and polymeric alpha-glucans were not attacked. Other properties of the purified enzyme were as follows: Temperature optimum for catalysis = 39 +/- 1 degrees C; pH optimum = 6.8; molecular weight = 27,000 +/- 1000. alpha-Glucosidase is proposed to function in the endogenous metabolism of alpha-glucans provided extracellularly as carbon sources for growth of B. amyloliquefaciens.


An alternative to allosteric interactions as causes of sigmoid dose versus response curves. Application to glucose-induced secretion of insulin.

It is shown that a sigmoid dose vs. response curve will occur in any biological system in which the stimulant compound must diffuse significant distances to reach responding cells, even when the cells themselves respond according to Michaelis-Menten kinetics. Isolated pancreatic islets releasing insulin in response to glucose stimulation have been used as a specific example. Since diffusion and/or other physical processes can produce global effects which could account for the sigmoidal nature of a dose vs. response curve, the existence of complex molecular mechanisms of hormone-receptor interaction can not be inferred solely from the character of a dose vs. response relation.


Preparation and characterization of liposomes containing the Ca2+-activated photoprotein, obelin.

1. Liposomes bearing different net surface charges have been prepared and their ability to entrap the Ca2+-activated photoprotein, obelin, has been studied 2. Negatively-charged liposomes, composed of egg-yolk lecithin, cholesterol and phosphatidylserine, consistently produced the most homogeneous populations of liposomes after sonication, as shown by electron microscopy after negative staining. These consisted of a large proportion of uni- and bilamellar vesicles within the size range of 20--50 nm, external diameter. 3. Sonicated negatively-charged liposomes had a mean aqueous obelin space of 6.8 +/- 0.8 microliter/mumol of phospholipid compared to a mean space for inulin [14C]carboxylic acid of 5.1 +/- 0.8 microliter/mumol of phospholipid. 4. Sonication reduced the Ca2+ permeability of the negatively-charged liposomes, as measured by the utilization of entrapped obelin. 5. Preparations of uncharged (no phosphatidylserine) and positively-charged (stearylamine instead of phosphatidylserine), sonicated liposomes contained a greater proportion of larger vesicles, which were more permeable to Ca2+ than sonicated, negatively-charged liposomes. 6. Obelin, trapped within sonicated, negatively-charged liposomes, responded to increases in the free Ca2+ concentration within the liposomes caused by the bivalent-cation ionophore A23187 at concentrations as low as 19 nM. 7. The effect of A23187 was inhibited by Mg2+ at a low concentration of Ca2+ (10 muM), but not at 1 mM Ca2+. 8. It was concluded that obelin could be trapped in the aqueous compartment of sonicated liposomes which remained relatively impermeable to Ca2+. Furthermore, trapped obelin could respond to changes in the free Ca2+ concentration within these liposomes.


Calcium and pancreatic beta-cell function. 2. Mobilisation of glucose-sensitive 45Ca from perifused islets rich in beta-cells.

beta-Cell-rich pancreatic islets were microdissected from ob/ob-mice and loaded with 45Ca in the presence of 3 or 20 mM glucose. Subsequent measurements of the effluxes of radioactivity in a perifusion apparatus revealed that the slowly exchangeable 45Ca taken up in response to glucose was also preferentially mobilised by this compound. Glucose stimulation of 45Ca efflux was abolished after omission of calcium from the perifusion medium but persisted when insulin release was inhibited by prolonged starvation, addition of L-epinephrine or lowering of temperature. The presence of a stimulated efflux of radioactivity even under conditions of inhibited insulin release indicates that sources other than beta-granules ejected by exocytosis contribute to the additional 45Ca released after raising the glucose concentration of the perifusion medium. It is suggested that the beta-cell depolarisation as such may account for part of the 45Ca mobilised by glucose.


Effects of phloretin and dextran-linked phloretin on pancreatic islet metabolism and insulin release.

The effects of phloretin on islet metabolism and insulin release have been studied in isolated pancreatic islets of the rat. At a concentration of 0.18 mM phloretin inhibited insulin release stimulated by glucose or leucine but did not affect the oxidation rates of glucose or leucine, the rate of glucose utilization and the islet content of ATP. Higher concentrations of phloretin caused inhibition of the rate of glucose metabolism, but stimulation of insulin release. Insulin release stimulated by phloretin was inhibited by mannoheptulose but was independent on extracellular Ca2+ and was not potentiated by caffeine. Both inhibitory and stimulatory effects of dextran-linked phloretin on insulin release were also seen; a concentration of dextran-linked phloretin that did not inhibit islet metabolism inhibited glucose-stimulated insulin release, but not release stimulated by leucine or glyceraldehyde. Higher concentrations of dextran-linked phloretin inhibited glucose oxidation but stimulated insulin release. These data are discussed in terms of current models of the beta-cell glucose-sensor mechanism.


Insulin degradation. XXIII. Distribution of glutathione-insulin transhydrogenase in isolated rat hepatocytes as studied by immuno-ferritin and electron microscopy.

The distribution of glutathione-insulin transhydrogenase (glutathione: protein-disulphide oxidoreductase, EC 1.8.4.2) in isolated rat hepatocytes that had been first treated with rabbit antiserum against purified rat liver transhydrogenase and then with ferritin-conjugated goat anti-rabbit gamma-globulin was examined by electron microscopy. In cells with intact plasma membrane, the immunoferritin labeling of glutathione-insulin transhydrogenase was observed on a few external microvillous projections at the outside of the cell. In cells with breaks in the plasma membrane, the immunoferritin labeling appeared extensively on smooth vesicles just inside the plasma membrane and on smooth endoplasmic reticulum extending to and including the outer nuclear membrane, in addition to the external microvillous projections. There was some immunoferritin labeling on rough endoplasmic reticulum and on the inner surface of the plasma membrane. The mitochondria and the outer surface of the plasma membrane of the cell did not show the ferritin labeling. Control parallel samples in which the antiserum was substituted with normal (i.e. non-immune) serum or with neutralized antiserum (prepared by absorption with the transhydrogenase) showed little or no immunoferritin labeling. These results are consistent with the idea that gluthalione-insulin transhydrogenase probably synthesized in the endoplasmic reticulum and that the transhydrogenase accessible to cell surface (or found in the isolated plasma membrane preparations) probably represents a functional continuity between the endoplasmic reticulum and the plasma membrane.


[The alpha-methylglucoside transport in Escherichia coli K12 cells].

The transport of alpha-methylglucoside (MG) in the wild type cells of Escherichia coli K12 and the isogenic mutant strains, defective in the activity of phosphoenolpyruvate: sugar phosphotransferase system components was studied. It was shown that the enzyme IIB' in the absence of enzyme I and HPr is able to transport MG into the cells by a "facilitated" diffusion mechanism. Compounds which dissipate the energy of membrane protone potential such as NaN3, carbonylcyanide-m-chlorophenylhydrasone, dicyclohexylcarbodiimide, enhance the utilization of MG by the wild-type cells. However, the cells retaining intact enzyme IIB' but deficient in the phospho approximately HPr-generating system, were not sensitive to the action of poisons. The cells possessing the intact phospho HPr-generating system and inactive enzyme IIB' are also unaffected by the poisons. It seems that these results do not confirm the hypothesis of the direct delta mu H+ involvement in the regulation of transmembrane phosphorylation. The hypothesis is postulated that the energy metabolism inhibitors influence the phosphatase activity of factor III of the phosphotransferase system. The present data are well explained by this hypothesis.


[Lysis of yeast protoplasts under sodium alkyl sulfates treatment].

The lytic action of homologous series of sodium alkyl sulfates on yeast protoplasts was studied. The concentration dependences study allowed to estimate the lytic concentrations C50 of the agents required for the 50% lysis of protoplasts in the suspension. The data concerning the agents micelle formation in the lytic medium allowed to make some suggestions and to produce a model of the lytic action of alkyl sulfates on the plasma membrane of the protoplasts. The amounts of the agents absorbed on the membrane and involved in the interaction followed by the membrane breakdown in the model are evaluated. On the basis of the data obtained it is concluded that sodium dodecyl sulfate displays the highest lytic activity to the yeast protoplast plasma membrane as compared to the other alkyl sulfates used  in the study. The results obtained are discussed in terms of the effect of yeast cell wall on the extraction of intracellular proteins from intact yeast cell under sodium alkyl sulfates action.


Combined Nomarski interference contrast and immunofluorescent study of neuropathological specimens: CSF sediments and paraffin embedded brain tissues.

The direct immunofluorescent technique may be easily improved by the use of the Nomarski optics. This contrast allows accurate identification of fluorescent CSF cells and structures in formalin fixed paraffin embedded brain tissues; in the latter, the combined optical procedure is fruitfull in order to avoid fluorescent artifacts misinterpretation. Furthermore, it is emphazised that the conditions in which routine neuropathological specimens are removed and stored usualy does permit the application of the immunofluorescent technique.


Preliminary results of phase I and II clinical trials of RFCNU, a new nitrosourea sugar derivative, in digestive tract tumours.

RFCNU or (chloro-2-ethyl)-l-(ribofuranosyl-isopropylidene-2', 3' paranitrobenzoate-5')-3 nitrosourea, a new synthetic nitrosourea derivative, which has been shown to have, in mice, among all nitrosourea derivatives tested, the longest maximallly efficient dose interval (MEDI) and which is not immunosuppressive at the smallest dose of MEDI, gave in a phase II trial on digestive tract tumours (at the dose of 400 mg/m2 per month determined by the phase I trial), 30% objective remissions among which 13% were greater than 50%.


Evidence for the lack of a carrier effect in the solvent extraction and determination of octopamine by gas chromatography mass spectrometry.

It has been shown that there is no significant carrier effect when low levels of [3H]octopamine (100 pg) are extracted by ethyl acetate from aqueous solutions containing a 10(3) or 10(6) times excess of unlabelled octopamine. It is also shown that there is no carrier effect when low levels of octopamine as the tetrakis-TMS derivative are injected with 100 times the amount of the [2H3] analogue on an SE 30 column.


[Reactions of antibodies to streptococcus group A antigens with fibroblasts of human heart interstitial connective tissue].

The indirect immunofluorescence method was applied to the study of the serum of rabbits immunized with fractions containing nontype-specific antigens of streptococcus, group A, belonging to the cell wall proteins. Antibodies reacting with fibroblasts of the interstitial connective tissue of the human heart were revealed in the sera. On the basis of the experimental results of absorption a supposition was put forward on the presence of a cross-reacting antigen common with the fibroblast antigen in some hydrochloric extracts obtained from streptococci, groups A and C.


[Relationship between antibody formation in cultures of lymphoid cells and incubation temperature].

An increase of the plaque-forming cells (PFC) and of the 3H-thymidine incorporation in the spleen cell cultures of immunized and nonimmunized C57BL/6 mice were studied in increase of the incubation temperature from 2 to 37 degrees C. An exponential rise of the PFC cells with the elevation of temperature and the presence of the "breaking" temperature, above which the rate of increase of the PFC cells displayed a sharp elevation, was demonstrated. The curves of intensification of the 3H-thymidine incorporation with the temperature elevation failed to follow the pattern of the PFC growth curve in a number of cases. Cultivation of immune cells at low temperatures led to the accumulation in the medium of some factors simulating the AFC formation.


[Enterotoxic activity of live cultures of Sonne dysentery microbes and formation of enterotoxin in vivo].

The great majority of virulent Sonne dysentery bacillus cultures caused an accumulation of the fluid in the lumen of the isolated segment of the rabbit small intestine containing a great amount of mucus and sometimes of the blood as well; the segment mucosa was hyperemic and had punctate hemorrhages. Avirulent microbial cultures as a rule caused no exudation in the intestinal lumen. Sterile and concentrated contents of the intestinal loops responding to the centrated contents of the intestinal loops responding to the administration of the virulent culture of Sonne bacillus or a toxigenic strain of Grigoriev-Shiga dysentery bacillus caused a positive response in other rabbits. The character of the exudate and the changes in the mucosa failed to differ from such following the administration of live cultures.


[Sensitivity of the central nuclei of the vagus to insulin deficiency in rats (histoenzymologic study)].

Distribution and activity of acetylcholine esterase (AChE) in the central vagal nuclei (Nucl. dorsalis and Nucl. ambiguus) in male intact rats and in rats with experimental alloxan diabetes were investigated. In alloxan-diabetic rats there was noted an increase of the number of cells with a high AChE activity in the Nucl. dorsalis by 6%. These data suggest the participation of the vagal dorsal nucleus in the control of the endocrine function of the pancreas.


[Immunohistochemical demonstration of cells containing melatonin and N-acetylserotonin].

The presence of cells containing N-acetylindolylalkylamines in the acini of the pancreas, at the border of the cortical and cerebral layer of the adrenal glands, under the capsule of the liver and in the vascular wall was shown by means of the immunohistochemical method with the use of specific antisera to melatonin and N-acetylserotonin. Further studies are necessary for the morphological identification of the type of these cells.


A possible modulatory role for prostacyclin (PGI2) INIgGa-induced release of slow-reacting substance of anaphylaxis in rats.

Antigen challenge in vivo of rat peritoneal cells (enriched with monocytes and polymorphonuclear leucocytes) passively sensitized 2 h previously with homologous antibody of the IgGa class released large amounts of slow-reacting substance of anaphylaxis (SRS-A, 1739 +/- 59 u/ml) into the peritoneal fluid. This reaction was strongly inhibited by prostacyclin (PGI2, ED50 = 0.5 microgram/kg i.p.) and by isoprenaline (ED50 = 0.2 microgram/kg i.p.) but prostaglandins E1, E2 and 6-oxo-prostaglandin F1alpha were only weak inhibitors. Indomethacin (10 mg/kg, orally) augmented by 30% the release of SRS-A, whereas thromboxane B2 (50 microgram/kg i.p.) had no effect. Lowering the antigen (ovalbumin) dosage from 400 microgram/ml to 10 microgram/ml reduced the control release of SRS-A by 70% and increased the inhibitory effect of prostaglandins I2, E1 and isoprenaline. Augmentation of release by indomethacin remained unchanged. These preliminary data suggested that endogenous prostacyclin may modulate the anaphylactic release of SRS-A from rat peritoneal cells.


Comparison of the vasodepressor effects of prostacyclin and 6-oxo-prostaglandin F1alpha with those of prostaglandin E2 in rats and rabbits.

1 Vasodepressor effects of prostacyclin (5z-5,6-didehydro-9-deoxy-6,9alpha-epoxyprostaglandin F1) and its decomposition product 6-oxo-prostaglandin F1alpha (6-oxo-PGF1alpha) have been compared with those of prostaglandin E2 (PGE2) in anaesthetized rats and rabbits. 2 In rats intravenous prostacyclin produced hypotension and was 4--8 times more potent than PGE2 and about 128 times more potent than 6-oxo-PGF1alpha. 3 In rabbits also, intravenous prostacyclin (less than 2 microgram/kg) produced hypotension and was twice as active as PGE2 and approximately 250 times more active than 6-oxo-PGF1alpha. 4 In rats and rabbits vasodepressor responses induced by prostacyclin were similar in magnitude after either intravenous or intra-aortic administration. 5 Thus, in both species prostacyclin resembles PGE2 in producing vasodepression but does not lose activity on passage through the lungs. The results emphasize the need to consider prostacyclin in addition to PGE2 as a major determinant influencing blood pressure.


The effect of the ionophores X-537A and A23187 on the noradrenaline output from peripheral adrenergic neurones in the presence of various divalent cations.

1 The effects of the ionophores, X-537A and A23187 on the noradrenaline output from peripheral adrenergic neurones of isolated vas deferens of the guinea-pig were investigated in the presence of various divalent cations.2 X-537A (17 muM) caused an increase in the noradrenaline output in the presence of barium, calcium and strontium. The effectiveness of the cations was Ba > Ca >/= Sr.3 In the absence of calcium and in the presence of ethyleneglycol-bis(2-aminoethylether)-N,N,N',N',-tetraacetic acid (EGTA, 1 mM), the response was reduced by about 50% of that obtained in the presence of calcium.4 Calcium was the most effective cation in stimulating noradrenaline output when reintroduced after pretreatment with A23187 (191 muM). The response increased in an almost linear fashion with the concentration of calcium 1 mM to 10 mM.5 Excess magnesium (20 mM) reduced the response induced by X-537A in the presence of barium. However, it was without effect on the response produced by reintroduction of calcium after pretreatment with A23187.6 The response induced by X-537A in the presence of barium increased with an increase in the concentration of external sodium from 25 mM to 143 mM.7 It is suggested that X-537A may cause an increase in the noradrenaline output by depolarization as well as by transferring cations as an ionophore. On the other hand, A23187 may produce an increase in the noradrenaline output, transferring calcium across the membrane as a specific calcium ionophore.


The biochemistry of brain development and mental retardation.

Mental retardation may be associated with a number of environmental factors such as undernutrition, lead poisoning or exposure to neuroactive drugs during a critical period of brain development. Possible biochemical mechanisms operating in these various conditions and in animal models are reviewed in relation to the vulnerable period hypothesis. Small brains are common in the mentally retarded, and this may be related to a developmental abnormality particularly at the level of the synapse.


The modified Makari skin test in urology--is it significant?

The Makari test is able to detect the presence of cancer in 95% of patients with primary tumours having excluded anergic patients. The test is useful in monitoring primary treatment. A long-term follow-up is necessary to determine the reason for patients' unexplained positive reactions in a control group of patients.


The treatment of oestrogen-escaped carcinoma of the prostate with estramustine phosphate.

30 patients with oestrogen-escaped carcinoma of the prostate have been treated with estramustine phosphate (Estracyt). 27% showed a partial objective response and 33% had a subjective response. The terms used for defining a response are challenged and it is recommended that comparative controlled trials are necessary to judge the place of this drug in the management of advanced prostatic cancer.


The clinical significance of antisperm antibodies in male subfertility.

Sera from 591 men attending Fertility Clinics have been tested for agglutinating, immobilising and immunofluorescent antisperm antibodies. There was good correlation between the presence of high titres (more than 1/32) of agglutinating and immobilising antibodies which were found in 50 patients (8.5%). 27 of these men had normal sperm counts, but crossed hostility testing showed that in 21 of 22 couples the sperms were unable to penetrate the cervical mucus, apparently because of the antibodies. 17 patients were treated with prednisone for an average of 6 months and 1 pregnancy was produced. 17 patients were treated with methylprednisolone for 7 days and 1 pregnancy resulted. No correlation was found between the present of immunofluorescent antibodies and the other antibodies of impaired sperm penetration of cervical mucus.


Factor VIII--related protein on vascular intima of patients with chronic renal failure and prolonged bleeding times.

To determine whether the prolonged bleeding time so common to chronic renal failure (CRF) was due to defective factor VIII-related activities, as in von Willebrand's disease, vascular-factor VIII-related protein was measured in patients with CRF. Factor VIII-related protein was detected by immunofluorescence on the vascular intima of all 13 patients with CRF and greatly prolonged bleeding times. This protein was also present on the vascular intima of a patient with CRF and moderate von Willebrand's disease. These findings support a previous suggestion that the disturbed haemostasis in patients with CRF is not linked to defective factor VIII-related activities.


Blood transfusion and renal allograft survival.

Thirty-two first renal transplantations with cadaveric allografts were reviewed to see how many of the recipients had received blood transfusions preoperatively. There was a significant difference in transplant survival between patients who had and patients who had not received blood transfusion before transplantation; this difference was entirely due to acute rejection within three months after transplantation in patients who had not received transfusion. Other factors studied had no effect on survival.


Rifampicin for lepromatous leprosy: nine years' experience.

Over 100 patients with lepromatous leprosy were treated with rifampicin in a series of pilot, uncontrolled, and controlled trials in 1968-77. The rapid bactericidal effect of rifampicin on Mycobacterium leprae was confirmed. Clinical improvement became apparent sometimes as early as 14 days after the start of treatment. Nevertheless, a few persisting viable M leprae were detected as long as five years after the start of treatment with rifampicin either by itself or in combination with the bacteriostatic drug thiambutosine. Treatment with rifampicin and dapsone for six months reduced the number of persisting leprosy bacteria more than treatment with dapsone alone. Although rifampicin proved more effective than dapsone, it is unlikely that used by itself if can significantly shorten the length of treatment in lepromatous leprosy. Therefore initial intensive combined treatment with two or more bactericidal drugs (including rifampicin) warrants further investigation in both untreated leprosy and lepromatous leprosy resistant to dapsone.


Continuous subcutaneous insulin infusion: an approach to achieving normoglycaemia.

A study was performed to examine the feasibility of achieving long periods of near-normoglycaemia in patients with diabetes mellitus by giving a continuous subcutaneous infusion of insulin solution from a miniature, battery-driven, syringe pump. Twelve insulin-dependent diabetics had their insulin pumped through a subcutaneously implanted, fine nylon cannula; the basal infusion rate was electronically stepped up eightfold before meals. The blood glucose profile of these patients was closely monitored during the 24 hours of the subcutaneous infusion and compared with the profile on a control day, when the patients were managed with their usual subcutaneous insulin. Diet and exercise were standardised on both days. In five out of 14 studies the subcutaneous insulin infusion significantly lowered the mean blood glucose concentration without producing hypoglycaemic symptoms; in another six patients the mean blood glucose concentration was maintained. As assessed by the M value the level of control was statistically improved in six out of 14 studies by the infusion method and maintained in six other patients. To assess the effects of blood glucose control on diabetic microvascular disease it will be necessary to achieve long-term normoglycaemia in selected diabetics. The results of this preliminary study suggest that a continuous subcutaneous insulin infusion may be a means of maining physiological glucose concentrations in diabetics. Though several problems remain--for example, in determining the rate of infusion--longer-term studies with the miniature infusion pumps are now needed.


Diabetic dimorphism according to acetylator status.

Two groups of diabetics and 19 normal controls had their rate of acetylation of sulphadimidine measured. Among 47 patients with maturity onset diabetes the 29 fast acetylators were older at diagnosis and, at a given glucose concentration, had a higher pretreatment fasting insulin concentration than slow acetylators. They also had a larger first-phase insulin secretion in response to intravenous glucose both before and after one month's dietary treatment. The greatest difference between fast and slow acetylators was in the first-phase secretion of insulin after a month's treatment. The proportion of fast acetylators among the second group of diabetics, who had been admitted to improve their glucose concentrations or for treatment of tissue damage, was similar to that among the normal controls (50% and 47% respectively). The data seem to indicate that diabetics are fast acetylators unexpectedly often, but it is not clear whether the dimorphism according to acetylator status produces a differential risk of neuropathy or of any other type of diabetic tissue damage.


Oral anticoagulants controlled by the British comparative thromboplastin versus low-dose heparin in prophylaxis of deep vein thrombosis.

The British comparative thromboplastin (BCT) was used to monitor the effectiveness of oral anticoagulants in preventing deep vein thrombosis (DVT) in patients undergoing major gynaecological surgery. All patients were screened for DVT with the use of the (125)I-fibrinogen scan.One hundred and forty-five patients aged 40 years or more were randomised into three groups. Group 1 received oral anticoagulant (nicoumalone) treatment, stabilised over five days before surgery and continuing into the second postoperative week. The other patients served as two contrast groups and were managed on a double-blind basis. Group 2 received a subcutaneous low-dose regimen of heparin calcium. Group 3 received subcutaneous saline. Eleven of 48 patients in the saline group, three of 49 patients in the heparin group, and three of 48 patients in the oral anticoagulant group developed DVT as judged by (125)I-fibrinogen scanning. The incidences in groups 1 and 2 were significantly lower than in the saline group. The falls in haemoglobin concentration and incidence of haemorrhage were similar in all three groups.The study showed that oral anticoagulant prophylaxis stabilised preoperatively and low-dose heparin were equally effective in preventing deep vein thrombosis in a moderate-risk group. Immediate preoperative prothrombin ratios of 2.0-2.5 and postoperative ratios of 2.0-4.0 with the BCT gave adequate protection without increased haemorrhagic risk.


Indoprofen and naproxen in the treatment of rheumatoid arthritis: a clinical trial.

Thirty-six patients suffering from rheumatoid arthritis took part in a double-blind crossover trial, in which they received either indoprofen 800 mg/day, naproxen 500 mg/day, or a matching placebo. Indoprofen was shown to be significantly superior as an analgesic and in improving grip strength and the patients preferred it. Adverse effects were comparable, although indigestion was seen slightly more often during indoprofen treatment. Indoprofen is therefore at least as effective as existing anti-inflammatory drugs in rheumatoid arthritis and seems to be better tolerated.


Synthesis of pppGpp by ribosomes from an Escherichia coli spoT mutant and the metabolic relationship between pppGpp and ppGpp.

Both ribosomes and a cell-free extract (S-30) prepared from an Escherichia coli spoT mutant catalyzed the synthesis of guanosine pentaphosphate (pppGpp) and guanosine tetraphosphate (ppGpp) as efficiently as did ribosomes and S-30 from a spoT+ strain. In both cases, the level of pppGpp reached its maximum before ppGpp maximally accumulated. pppGpp added to the ribosome system was rapidly converted to ppGpp. These results indicate that the spoT+ gene product may not have a direct role in the synthesis of pppGpp and that pppGpp is a precursor of ppGpp.


Differential effect of D-glucose anomers on proinsulin biosynthesis by the pancreatic islets.

Pancreatic islets of Langerhans of the rat were used to study effects of D-glucose anomers on the incorporation of [3H]leucine into proinsulin and other islet proteins. At low (1 mg/ml), but not at high (2 mg/ml) glucose concentration, the alpha-anomer stimulated more proinsulin biosynthesis than the beta-anomer. This observation adds to the growing list of islet functions showing anomeric preference for alpha-D-glucose.


L-methionine as an ethylene precursor in Saccharomyces cerevisiae.

L-Methionine induced production of ethylene by Saccharomyces cerevisiae growing in lactate medium. The production induced by L-methionine was inhibited by pyruvate, and elevated by glucose. Labeled ethylene was produced when L-[U-14C]methionine, but not [U-14C]glucose, was fed to the yeast. The mutant S. cerevisiae G1332 (ade-, met-) did not produce significant amounts of ethylene unless L-methionine was added. Thus L-methionine acts as a precursor of ethylene in S. cerevisiae. The role of glucose appears to be other than as a precursor.


The effect of rifampicin on the developmental phases of germinating spores of Clostridum sp., MSp+.

The effect of rifampicin on the developmental phases of germinating spores of Clostridium botulinum, MSp+, has been studied. At sublethal concentrations of rifampicin (0.05 ng/ml) the time periods required for outgrowth and vegetative growth was significantly prolonged because of the inhibition of RNA and protein synthesis. However, rifampicin had essentially no effect on DNA synthesis or on subsequent spore formation. Chemical analyses showed that the amount of protein present in vegetative cells of the rifampicin-treated cultures was twice as great as in the untreated cultures but the total protein content of endospores was the same in both cases. It was revealed in ultrastructural studies of rifampicin (0.1 ng/ml) treated cultures, examined after 22 h, that septum formation and normal cell division of the emerging cell was blocked and a few cells showed constriction which produced one normal and one protoplast-like daughter cell.


Microscopic examination of natural sessile bacterial populations from an alpine stream.

Natural populations of bacteria assoiciated with the slime on submerged surfaces in a mountain stream were examined by phase-contrast and electron microscopy. The slime contained large numbers of bacteria which were predominantly gram-negative as determined by their cell wall structure. Examination of the in situ distribution of cells revealed that they were enmeshed in an extensive fibrous matrix whose component fibrils were stained with ruthenium red. The arrangement of slime fibrils immediately around individual bacterial cells suggested that this material was produced by these bacteria. This slime facilitated microcolony development and also anchored the bacteria to a particular surface. It is proposed that these slime-enmeshed microcolonies constitute functional communities within which most sessile bacteria live.


Symposium on intensive care: 4. Respiratory failure.

Patients requiring respiratory support may have normal lungs but inadequate ventilation, or they may suffer from defective pulmonary gas exchange despite adequate ventilation. In the first group some form of mechanical ventilatory support is called for, either pressure-cycled or volume-cycled, used first with an endotracheal tube and only later with a tracheostomy. Weaning the patient from the apparatus requires special care. In cases of pulmonary insufficiency the use of positive end-expiratory pressure has been a major advance. Hemoglobin concentration, cardiac output and renal function must receive attention. Open lung biopsy is of the greatest value when the diagnosis is open to question. Resort to a membrane oxygenator to provide extracorporeal oxygenation of blood can sustain for a time the patient in whom hypoxia is critical in degree.


Demonstration of cellular and humoral immunity to transplantable carcinomas derived from the respiratory tract of rats.

Previous studies with respiratory tract tumors in mice have suggested that such tumors are not immunogenic or are only weakly so. To determine whether this is a general characteristic of neoplasias found in the airways of rodents, we investigated seven transplantable carcinomas in rats, six of which originated from tracheal epithelium and one of which orginated from the distal lung. These carcinomas were all of the squamous type and were induced by three different carcinogenic polycyclic hydrocarbons. All of the tumors were shown to be immunogenic, capable of mobilizing cellular and humoral immune responses in isogenic hosts upon immunization. This was demonstrated by induction of transplantation resistance, by Winn's neutralization test, and by the detection of antibodies in the sera of tumor-immune hosts by two independent methods (antibody-dependent cytotoxicity and antibody-binding test). The degree of immunogenicity varied among the tumor lines. The most metastatic tumor was clearly the least immunogenic. The relationship between carcinogenic insult and immunogenicity, as well as the possible nature of the tumor-associated antigens involved, is discussed.


Immunochemical evidence of a tumor-specific surface antigen obtained by detergent solubilization of the membranes of a chemically induced sarcoma, meth-A.

We reported previously the partial purification of detergent-solubilized specific tumor rejection antigen of a chemically induced sarcoma, Meth-A. During the course of the study, rabbit antiserum against a partially purified specific tumor rejection antigen preparation was raised and rendered specific by in vivo absorption. In this report we show that an antigenic molecule defined by in vivo-absorbed rabbit antiserum, which we tentatively refer to as tumor-specific surface antigen, was solublized by detergent Nonidet P40, and extensive attempts at purification were carried out by a sequence of procedures including gel filtration, isotachophoresis, and polyacrylamide gel electrophoresis. The most highly purified tumor-specific surface antigen retained some specific tumor rejection antigen activity, suggesting an association of the two activities. Both antigens were shown to have a molecular weight of about 60,000 and an electrophoretic mobility of alpha-globulin.


Serological reactivity in cancer patients to human and mouse fetal liver cells.

The occurrence of antibodies to human and mouse fetal liver cells has been quantitated in the sera from patients with carcinoma of breast, colon, and lung and with malignant melanoma. Also, we have demonstrated cross-reacting murine antibodies in the sera from multiparous, antifetal, and pregnant mice, which bind to mouse fetal liver cells and/or several types of human tumor cells. A comparative evaluation of these antibodies with two immunological techniques has demonstrated a greater number of positive sera from cancer patients assayed by isotopic antiglobulin (25 of 27, or 92%) than by membrane immunofluorescence (12 of 17, or 71%). In the non-cancer control group, positive reactions were found in 11 and 31% by the two techniques, respectively. The specificity of such serologically reactivity has been demonstrated by adsorption with fetal liver cells. These detected antibodies are not restricted to a particular type of human neoplasm, but rather to the presence of cancer. Because of their relative capacity of discrimination between benign and malignant conditions and because the assay for their detection is relatively simple, these techniques may provide alternative methods for diagnosis or monitoring of cancer patients.


Detection of mutagenic impurities in carcinogens and noncarcinogens by high-pressure liquid chromatography and the Salmonella/microsome test.

We have used high-pressure liquid chromatography and the Salmonella/microsome mutagenicity test to look for mutagenic impurities in 11 carcinogens and noncarcinogens. Because of the million-fold range in mutagenic potency observed in the Salmonella test, even trace amounts of potent mutagenic impurities in a nonmutagenic compound could be detected. The mutagenicity of 7-hydroxy-2-acetylaminofluorene, a noncarcinogen in the standard animal carcinogenicity tests, is shown to be due to a small amount of impurity, which is probably the potent carcinogen 2-acetylaminofluorene. This is discussed in relation to the statistical limitations of animal carcinogenicity tests. We also discuss the role of mitogenic impurities in assessing the mutagenicity of environmental (and industrial) chemicals with high-sensitivity mutagenicity assays, such as the Salmonella/microsome test.


Phase II trial of piperazinedione in Hodgkin's disease, non-Hodgkin's lymphoma, and multiple myeloma: a Southwest Oncology Group study.

Piperazinedione given iv once every 3-4 weeks at a starting dose of 9-12 mg/m2 (4.5-12 mg/m2 for patients with myeloma) was evaluated in a Southwest Oncology Group phase II study for patients with far-advanced refractory lymphoma or multiple myeloma. Among 36 patients fully evaluable for tumor response (adequate trial), partial responses were observed in five (71%) of seven patients with Hodgkin's disease, in three (19%) of 16 patients with non-Hodgkin's lymphoma, and in none of 13 patients with multiple myeloma. Response was observed by the time of the second (five patients) or third (three patients) course. The median duration of response was 3.7 months (range, 1-17+ months). The dose-limiting toxic effects were hematologic, with 18 (50%) of 36 patients evaluable for toxicity experiencing severe leukopenia (wbc count less than 2000/mm3) and 22 (61%) experiencing severe thrombocytopenia (platelet count less than 50,000/mm3). Twenty patients had a decrease from their pretreatment hemoglobin level of greater than or equal to 2 g/100 ml. Hematologic toxic effects were often unpredictable and in several patients quite prolonged. This study indicates that piperazinedione had definite antitumor activity in patients with Hodgkin's disease and further trials in this disease using the drug at a reduced dose in combination with other effective drugs appear warranted.


Treatment of metastatic breast cancer with adriamycin-cyclophosphamide induction followed by alternating combination therapy.

Thirty-four patients with metastatic breast cancer and no prior chemotherapy were treated with an induction regimen of four courses of adriamycin-cyclophosphamide followed by a fixed sequence of three courses of methotrexate-5-fluorouracil alternating with each course of adriamycin-cyclophosphamide. In this protocol, adriamycin can be administered for a minimum of 18 months before the dose of 550 mg/m2 is reached. The objective response rate was 56% (19 of 34 patients) with three complete responses and 16 partial responses. The median duration of response is 219 days and six of 19 patients remain in remission. The median survival of responders is 469 days while the nonresponders and progressors have a median survival of 273 days. The chemotherapy was administered in the outpatient department and was well tolerated. The scheduling of drugs in this study does not appear to result in significantly different response rates, duration of responses, or survival compared to those protocols in which these drugs are administered simultaneously.


Immunohistochemical and ultrastructural identification of the pancreatic polypeptide-producing cell (PP-cell) in the human pancreas.

The consecutive semithin--thin section method was employed to identify pancreatic-polypeptide-containing cells in the human pancreas. The immunocytochemical staining of semithin sections with the peroxidase-antiperoxidase complex allowed a precise ultrastructural description of the immunoreactive cells on the adjacent thin section. Two populations of small granulated cells could be distinguished with this technique: one group is formed by cells whose secretory granules with a mean diameter of 141 nm show specific immunoperoxidase staining with anti-PP serum, while the other group consists of cells whose secretory granules measuring 118 nm in diameter show no immunoreactivity to anti-PP serum. The former cells which will be designated as PP-cells, are not identical with the D1-cells of the revised Wiesbaden classification of endocrine cells.


Histological, immuno- and enzyme-histochemical investigations on the adenohypophysis of the urodeles, Mertensiella caucasica and Triturus cristatus and the caecilian, Chthonerpeton indistinctum.

The pituitary glands of two urodelan species (Mertensiella caucasica, Triturus cristatus) and one one caecilian species (Chthonerpeton indistinctum) were examined with histological (Alcian blue, Brookes' trichrome stain), enzyme histochemical (acid phosphatase, alpha-naphthylacetate-esterase, acetylcholinesterase) and immunofluorescence techniques (anti-carp GTH, anti-ovine prolactin, anti-synthetic alpha-MSH). In the pituitary gland of Mertensiella and Triturus six chromophilic cell types could be distinguished. A strong fluorescence was observed in the MSH-, GTH- and TSH-cells. In the pituitary gland of Chthonerpeton only five chromophilic cell types could be distinguished: in the rostral part of the pituitary gland the B3-cell; in the basal region of the central area the B2-cell; dorsocaudally the B1-cell. The acidophilic cells were found in the central and caudal part of the pars distalis. The basophils of the pars intermedia could be observed in the dorsocaudal part of the pituitary gland surrounding the neurohypophysis. All acidophilic cells showed a strong immunofluorescence with anti-ovine prolactin (LTH).


Ultrastructural changes in muscle mitochondria in situ, including the apparent development of internal septa, associated with the uptake and release of calcium.

Treatment of mammalian muscle with the divalent cation ionophore A23187 causes the release of Ca2+ from the sarcoplasmic reticulum and allows the ultrastructural changes of the mitochondria during Ca2+-uptake to be demonstrated in situ. Electron micrographs reveal that the mitochondria swell dramatically during uptake, before contracting again when the accumulated Ca2+ is released once more into the cytoplasm. When maximally swollen, the mitochondria are apparently subdivided and internal "septa" are formed. The ultrastructural details concerning these internal membranous structures are shown in detail and their significance is discussed.


Questioning of reported evidence for guanosine tetraphosphate synthesis in a ribosome system from mouse embryos.

In 1974, Irr, Kaulenas and Unsworth reported that ppGpp is synthesized by cytosolic ribosomes from mouse embryos and proposed a role for ppGpp in the process of differentiation. This proposal is being challenged because ribosomes of mouse embryos from various stages of development and of mouse embryoid bodies were completely inactive in ppGpp formation.


10 nm filaments in normal and transformed cells.

An antibody was raised against an electrophoretically homogeneous protein from cultured fibroblasts and shown to be directed against 10 nm filaments. The antiserum did not stain microtubules or actin microfilaments. The distribution of 10 nm filaments in normal cells was studied during growth, spreading, locomotion, mitosis, and after treatment with colchicine and cytochalasin B. The 58,000 dalton subunit protein is apparently all polymerized in the filaments which are insoluble in nonionic detergent. The distribution of 10 nm filaments is altered by colchicine treatments which disrupt microtubules. The organization of 10 nm filaments is altered in transformed cells.


Maximizing gene expression on a plasmid using recombination in vitro.

Recombination in vitro has been used to place one or more copies of a strong promoter, the lac promoter, at varying distances from the cl (repressor) gene of bacteriophage lambda on the E. coli plasmid pMB9. In all constructions, lambda repressor synthesis is driven wholly or predominantly by the inserted lac promoter. One of our fusions directs the synthesis of very high levels of lambda repressor. In this case, the fused DNA encodes a ribosome binding site which is a "hybrid" of lambda and lac sequences. In principle, this method of construction should elicit high levels of expression in E. coli of any gene, whatever its source. We also described strains with different sequence arrangements that, for reasons not completely understood, produce less repressor.


On the nature of tetracycline resistance controlled by the plasmid pSC101.

In vitro enzymatic alteration of plasmid phenotype and in vitro construction of recombinant plasmids containing genetic information derived from the plasmid pSC101 have been used to investigate the mechanism of function of tetracycline resistance determined by the plasmid pSC101. The resistance has been shown to be inducible and involves the increased synthesis of membrane-associated polypeptides of 34,000, 26,000 and 14,000 daltons that are encoded for by the plasmid. The 34,000 dalton polypeptide along with another plasmid-encoded polypeptide of 18,000 daltons function in an ATP-independent manner to prevent the accumulation of tetracycline by the cell. These polypeptides are sufficient for resistance. A second component of plasmid-determined resistance involves the 14,000 dalton polypeptide and reduces the initial adsorption of tetracycline by sensitive cells, but is not alone sufficient for the generation of resistance. The role of the 26,000 dalton polypeptide in tetracycline resistance has not been identified.


Effect of triethyltin on Escherichia coli K-12.

Triethyltin (TET) stimulated the basal respiration of Escherichia coli K-12 membrane vesicles in chloride (Cl-) medium but it had little effect on respiration in sulphate (SO4(2-)) medium. Since this uncoupling activity was Cl- dependent it was attributed to the Cl-/hydroxide (OH-) exchange reaction known to be mediated by TET [1,2]. TET inhibited the oxidation of succinate by intact E. coli in both Cl- and SO4(2-) medium, but at the same concentration of TET, inhibition was always more extensive in Cl- than SO4(2-) medium. In Cl- medium uncoupling in membrane vesicles and inhibition of succinate oxidation in intact bacteria occurred over the same concentration range and it appeared that the same mechanism, i.e. Cl-/OH- exchange, was responsible for both effects. Inhibition of succinate oxidation in SO4(2-) medium was not substantial until the concentration of TET was greater than 10(-5) M. Although the nature of this inhibition could not be determined by experiments with membrane vesicles indirect evidence from growth experiments indicated that it was due to impairment of oxidative phosphorylation. The relationship between these biochemical findings and the bacteriocidal action of TET was examined by using various concentrations of anion and substrate in the growth medium. Growth was inhibited in media containing either Cl- or SO4(2-) as the main anion but at a particular concentration of TET, inhibition was greater in Cl- medium. Growth was also inhibited to a greater extent in succinate than glucose medium. Furthermore in either Cl- or SO4(2-) glucose medium, lactic acid production increased as the concentration of TET was increased. These findings imply that the bacteriocidal action of TET is related to its effect(s) on oxidative phosphorylation.


[Value of the indirect immunoperoxidase reaction in the sero-diagnosis of amebiasis].

The number of our findings is still to small to draw definite conclusions. They however show that this technique is very sensitive and highly specific for the diagnostic of tissular amebiasis. Moreover, it significantly reduces the reading difficulty, because the morphologic differences between ameba and the other elements of the antigen is easy to see. The other advantages of the method are: the use of usual optic microscope, which allows the serologic diagnostic in moderatly fitted out laboratories, the use of electron microscope which allows the study of internal structure of the parasite, the preservation of the slides for several months, permitting therefore comparative studies.


Pulmonary tuberculosis due to BCG in a technician employed in a BCG laboratory.

X-ray examination of the lungs of a laboratory technician in the BCG Department of the Statens Seruminstitut, Copenhagen revealed a lung tumour and possible signs of tuberculosis. The diagnosis was confirmed by macroscopic and histopathological examination of lung tissue removed by surgery. Subsequent bacteriological examination showed the infection to have been caused by BCG. The possibility is discussed of whether the condition had developed from a metastatic lesion following BCG vaccination, or was the result of an aerogenic infection during the production of BCG vaccine. The simultaneous development of the tuberculous condition and the tumour is remarkable but is not discussed further. The requirements of WHO when signs of tuberculosis are found in a worker in a BCG laboratory were complied with in this instance, but it was not considered necessary to change the routine procedure in the BCG Department.


Enterotoxin antibodies in relation to diarrhoea in Swedish soldiers in Cyprus.

The development of antibodies to Escherichia coli heat-labile enterotoxin (LT) and its relationship to diarrhoea was studied in two Swedish battalions (one in the winter, WB, and one in the summer, SB) of the United Nations Peace-keeping Force in Cyprus. Whereas only 6-15% of the soldiers had detectable levels of anti-LT antibodies in their sera before leaving Sweden, as many as 69% of the SB and 43% of the WB soldiers who developed diarrhoea in Cyprus acquired significant titres of enterotoxin antibodies in their sera (acute phase serum). During the summer, many soldiers without diarrhoea also obtained anti-LT antibodies, whereas no such response was observed in healthy soldiers during the winter. Civilian Turkish Cypriots had positive sera in high frequency (60-66%) during both study periods. Parallel titration of positive sera against E. coli LT and cholera toxin indicated that the enterotoxin-neutralizing antibodies registered were induced by bacteria producing enterotoxin identical or closely related to LT.


[Comparative study of the indirect immunofluorescence and indirect immunoperoxidase reactions in bilharziasis].

The immunoperoxidase technique is easy, specific and very sensitive. Its allows the diagnostic of bilharziosis in 97 % of the patients. The test is considered as specific with titers equal or higher than 1/80. Thanks to its relative easiness, high sensitivity and high specificity, this technique permits to read the findings on an usual optic microscope and before all to preserve the slides for several months, and therefore to carry out comparative studies.


Laboratory infection of Anopheles pharoensis with Wuchereria bancrofti.

A. pharoensis was infected from a donor with a high count of W. bancrofti microfilariae. Of the freshly dissected mosquitos, 81.6% were found to have ingested microfilariae, with an average of 12 +/- 2.2 microfilariae per mosquito. An infectivity rate of 41.9% was observed in mosquitos dissected between the eleventh and fifteenth days after feeding. A mean of 7.6 +/- 1.2 third-stage larvae was found in infective mosquitos. Although A. pharoensis has not yet been found naturally infected with third-stage larvae of W. bancrofti, these studies suggest that it is a potential vector of Bancroftian filariasis.


Endotoxin-induced increased alveolar capillary membrane permeability.

In an attempt to define the effects of endotoxin on the permeability of the pulmonary alveolar capillary membrane (ACM) to a variety of substances [molecular weight (MW) varying from 60 to 69,000], we studied the movement of specific molecular species from the pulmonary capillary blood to the saline-filled "alveolus," employing an in vivo dog lung model. Following endotoxin injection (2-2.5 mg/kg) baseline T1/2 values (time, in minutes, for 50% equilibration of the specific solute between the blood and the saline-filled lung) decreased as follows (compared to baseline values): urea (MW 60) - 42.5 +/- 24 to 21.3 +/- 18; sucrose (MW 360) - 201 +/- 72 to 76 +/- 53; 3,000 MW dextran - 1,275 +/- 746 to 686 +/- 433; 10,400 MW dextran - 1,871 +/- 845 to 1,052 +/- 630 (all p less than 0.05). Neither 20,000 MW dextran nor albumin (MW 69,000) showed an increased permeability following endotoxin injection. Histamine analysis revealed a significant increase in all lung liquid samples post-endotoxin injection without a significant increase in blood histamine values. We conclude that, acutely (within 4 hr of injection), endotoxin causes an increase in permeability of the ACM for substances up to 10,400 MW. The role of histamine in this increased permeability remains controversial.


Cardiovascular responses to PGI2 (prostacyclin) in the dog.

Arachidonic acid (AA) produces characteristic hemodynamic changes in the canine circulation. These responses are blocked by prostaglandin (PG) synthetase inhibitors, indicating that AA and its nonprostanoic metabolites are not vasoactive. The hemodynamic effects of the cyclic endoperoxides, thromboxanes, and PGD2, PG2, and PGF2a differ from those produced by AA. PGI2, a newly identified product of AA, is reported to relax arterial strips. However, its cardiac and systemic effects are unknown. In 12 open-chest, anesthetized dogs, PGI2 (0.25-5.0 microgram/kg) produced a dose-related decrease in systemic arterial pressure (BP) and myocardial contractile force (MCF). In five left ventricular bypass preparations, PGI2 produced only a slight decrease in MCF at all doses, whereas the BP decreases were parallel to those in the intact preparation. AA, PGD2, PGE2, and PGI2 were administered in random order by bolus intravenous injections in approximately equidepressor doses to intact dogs. BP fell with each agent (AA, 300 microgram/kg, -25 percent; PGD2, 5 microgram/kg, -26 percent; PGE2, 5 microgram/kg, -26 percent PGI2, 0.5 microgram/kg, -26 percent). The vasodepressor action of PGI2 was approximately 10 times greater than that of PGD2 and PGE2. Pulmonary arterial pressure (PAP) rose significantly with PGD2 and PGE2 (AA, -1 percent; PGD2 +66 percent; PGE2, +20 percent; PGI2, -1 percent). Only PGE2 had a significant effect on MCF (AA, +7 percent; PGD2, +5 percent, PGE2, +20 percent; PGI2, -0.3). At this dose, PGI2 resembles AA in that it has little effect on either PAP or MCF. Of all known AA metabolites the response to PGI2 most closely resembles that of exogenous AA in the dog.


Polarisation fluoroimmunoassay of phenytoin.

A polarisation fluoroimmunoassay for the determination of phenytoin levels in serum is described. Fluoresceinthiocarbamyl alpha,alpha-diphenylglycine (FTC-DPG) is used as an easily prepared fluorescent-labelled analogue of phenytoin. Interference from the non-specific binding of FTC-DPG by serum proteins is eliminated by proteolytic degradation of samples prior to assay. The method employs stable, non-radioactive reagents, requires no separation procedure, and involves only 1.25 microliter of serum. Analyses of serum samples from patients receiving phenytoin correlate well (r = 0.96) with an established gas-liquid chromatographic method.


Observational studies of children from diary to ethnogram. A century of progress.

A survey of methodology within observational study is attempted. Personalized baby biographies are seen to provide a foundation for more rigorous study including time and event sampling utilizing technological aids. The essence of ecology is included within an increasingly objective approach leading up to the possibility of utilization of the principles and practice of ethology. Naturalistic observation can be seen to be a necessary element within modern behavioral study.


Possible persistent endocrine function of a rejected renal allograft.

The case is described of a patient on intermittent hemodialysis who had had a bilateral nephrectomy but had hypertension and a surprisingly mild degree of anemia. Repeated determinations showed high plasma renin activity and plasma erythropoietin activity within the detectable range. These results were thought to be related to a completely calcified renal allograft which had been inserted 8 years before and which had been rejected four years later, but left in situ. The patient had become anuric. It is suggested that chronically rejected renal allografts, even calcified, may maintain some endocrine activity in the absence of any excretory function.


Toxoplasmosis after renal transplantation.

Infection is the main cause of death following renal transplantation. In the literature 7 fatal cases of toxoplasmosis following renal transplantation have been described. In the present papers a case of reactivated toxoplasmosis is presented where the patient survived. Fortuitous withdrawal of therapy and transplant nephrectomy may have been responsible for the patient's survival. The problems of diagnosis of toxoplasmosis following renal transplantation are discussed. Early diagnosis is vitally important as successful treatment of toxoplasmosis with pyrimethamine and sulfonamides in patients receiving immunosuppressive therapy has been reported. It is emphasised that reaction of toxoplasmosis should always be considered in patients with fever of unknown origin and cerebral symptoms.


A new technique for measuring blood flow in polytetrafluorethylene grafts for hemodialysis.

A method has been described for the measurement of blood flow in non branching grafts using the isotope dilution principle. The technique is simple, reproducible and consistent and can be performed in less than ten minutes.


Preliminary clinical evaluation of the effect of small electrical currents on the healing of jaw fractures.

A clinical investigation has been carried out into the effect of small electrical currents on the healing of mandibular fractures. Electrical stimulation of fracture healing was carried out in 40 patients with a direct current of 10 or 20 microamperes delivered through a platinum electrode. An equal number of patients with similar fractures were selected as controls. Rate of repair was assessed by measuring the mobility of the fracture. Serum phosphatase and calcium were regularly measured at intervals in both groups after reduction and suggested that alkaline phosphatase activity increased in the stimulated group. The repair process was enhanced in the electrically stimulated fractures compared to the controls in the first 10-14 days after reduction.


Techniques of anterior spinal surgery for the management of kyphosis.

Experience with the techniques of spinal surgery for the management of thoracic and lumbar kyphosis suggests that the anterior approach is useful for correcting fixed deformity (achieving solid arthrodesis and decompressing the spinal cord when necessary). The insertion of an anterior bone graft alone does not guarantee a solid arthrodesis. Meticulous technique, autologous bone, and efficient immobilization are essential for a satisfactory result.


Section II: General orthopaedics. Anterior cervical fusion for trauma.

Anterior bone grafts of 24 injured cervical spines were reviewed with respect to early postoperative instability and eventual malunion. Spinal redislocation or graft extrusion occurred in 21% representing failure to attain early stability. In 38%, the late complication of kyphotic malunion occurred, averaging 21%. The Yale instability criteria were fulfilled in 15 cases and mechanical complications developed in 87% of these. When posterior instability was present, the mechanical complication rate rose to 92%. Early stabilization of most neck injuries is not achieved by the anterior bone graft and its use as a means of "stabilization" is unsubstantiated by clinical experience.


Fixation of osteochondral fragments in the knee joint. A clinical survey.

In 20 patients with osteochondral joint fragments (chiefly osteochondritis dissecans), followed for an average of five years, excellent or good results were obtained in 15 treated by transfixation with autologous cortical bone pegs.


Percutaneous repair of acute closed ruptured achilles tendon: a new technique.

The technique of percutaneous suturing repair of acute closed rupture of the Achilles tendon, as described in this article, can be performed under local anesthesia without using an arterioconstrictive tourniquet. Eighteen patients have been successfully treated with this technique, 12 having been closely followed for more than 12 months, and 8 for more than 24 months. Preliminarly, this technique for repairing acute closed Achilles tendon ruptures appears more promising than open surgical repair or short leg equinus casts alone due to tendon continuity restoration, tendon strength restoration,and minimization of postoperative complications.


Stabilization of the collapsing spine in duchenne muscular dystrophy.

Of 41 patients with Duchenne muscular dystrophy, no ambulatory patient had scoliosis greater than 19 degrees. Non-ambulatory patients were prophylactically placed in body jackets, which kept the spine flexible and provided adequate support for sitting in the majority of patients. Ten patients had posterior spine fusion for progressive spinal collapse. The procedure was extensive with significant blood loss but boney fusion was achieved in every case. Pulmonary complications were minimized by performing preoperative tracheostomy on all patients who had vital capacities less than 40% and or non-functional coughs. Spinal fusion permitted long-term sitting stability despite the progression of the disease.