Cysteine sulfinic acid in the central nervous system: antagonistic effect of taurine on cysteine sulfinic acid-stimulated formation of cyclic AMP in guinea pig hippocampal slices

The stimulatory effect of cysteine sulfinic acid on cyclic AMP formation was examined in slices from three different regions of guinea pig brain. The inhibitory effect of taurine on the stimulated formation of cyclic AMP was also studied. Cysteine sulfinic acid (1--10 mM) greatly increased the cyclic AMP level in striatal, cortical, and especially hippocampal slices. In hippocampal slices, taurine (0.1--30 mM) markedly lowered the increase of cyclic AMP induced by cysteine sulfinic acid, but not that induced by glutamate or aspartate. In this region, taurine also reduced the stimulatory effects on cyclic AMP formation of adenosine, norepinephrine, and histamine, but not of depolarizing agents. It did not, however, inhibit the effects of any of these stimulants in cortical slices. These results suggest that sulfur-containing amino acids, such as cysteine sulfinic acid and taurine, regulate the cyclic AMP level in the hippocampus.

A search for an enriched source of polymeric IgA in human thoracic duct lymph, portal vein blood and aortic blood

Because human bile contains a lot of secretory IgA, it has been suspected that the human liver, like rat liver, transfers polymeric IgA from plasma to bile. Hence, a rich source of polymeric IgA might enter the general circulation of man. We examined human thoracic duct lymph, portal vein blood and aortic blood for content and molecular size of IgA. None of the fluids was found to have either a higher total concentration of IgA or a higher proportion of polymeric IgA than that found in peripheral venous blood. It is possible that hepatic clearance of plasma IgA does not occur in man to the extent that it does in the rat, and a relatively larger proportion of human biliary IgA might originate from synthesis in hepatobiliary tissues.

Activation of adenylate cyclase of rat brain by lipid peroxidation

The relationship between adenylate cyclase activity in the synaptic membrane fraction (M1) of rat brain and lipid peroxidation of these membranes was examined. In the presence of 5 mM dithiothreitol (DTT), 1 to 10 microM Fe/+ activated adenylate cyclase 2- to 4-fold. Of several metal ions, Fe2+ was the most effective. Other enzymes in M1, such as Mg2+-ATPase, (Na+-K+)-ATPase, 5'-nucleotidase, acetylcholinesterase, and phosphodiesterase, were not activated by Fe2+ plus DTT. Activation of adenylate cyclase by Fe2+ plus DTT was accompanied by production of malondialdehyde, a product of lipid peroxidation. Formation of malondialdehyde was completely parallel with enzyme activation. Ascorbic acid or a NADPH system also stimulated enzyme activity and caused lipid peroxidation. Activation of the enzyme and lipid peroxidation induced by Fe2+ plus DTT, ascorbic acid, or NADPH was completely prevented by simultaneous addition of N,N'-diphenyl-p-phenylenediamine, an inhibitor of lipid peroxidation. This inhibitor also prevented the decrease in turbidity of the enzyme preparation induced by Fe2+ plus DTT. The stimulatory effects of NaF, guanylyl-5'-imidodiphosphate and calmodulin, respectively, and that of Fe2+ plus DTT on the enzyme activity were additive. Activation of adenylate cyclase by Fe2+ plus DTT was only observed in brain synaptic membranes, not in erythrocyte ghosts, liver plasma membranes, or cardiac sarcolemma. These results indicate that lipid peroxidation of synaptic membranes was accompanied by specific stimulation of adenylate cyclase activity.

Dicentric isochromosome for the long arm of chromosome #17, dic i(17q), in a patient with chronic myelogenous leukemia (CML)

Cytogenetic studies in a 33-year-old male patient with chronic myelogenous leukemia of 7 years duration revealed a so-called i(17q) chromosome marker and other cytogenetic abnormalities during the early phase of blastic crisis which were not present at diagnosis. Careful morphologic examination of this marker using G- and C-banding techniques revealed it to be a dicentric chromosome with a very short intercentromeric area. The fact that the dicentric nature of this marker was not apparent with the conventional Giemsa stain emphasizes the usefulness of the C-banding technique in defining the origin of this important cytogenetic marker.

Angiosarcoma of the heart: ultrastructural study

Two angiosarcomas of the heart, both arising from the right atrium, were studied with the electron microscope. Ultrastructural characteristics of angiomatous development were demonstrated both at the better differentiated vascular areas and at the less differentiated, spindle-cell foci. Both tumors were dominated by immature endothelial cells. These cells were associated with primitive mesenchymal cells and transitional forms of pericytes. Intracytoplasmic lumen formation and junctional specialization with neovascular development are unique features of angiogenesis in these tumors. Ultrastructural studies may provide useful diagnostic features separating a true malignant vascular neoplasm of endothelial cell origin from other forms of mesenchymal neoplasia that may have a prominent stromal vascular component.

Orthotopic bone transplantation in mice. III. Methods of reducing the immune response and their effect on healing

Various methods of reducing the immune response to allogeneic bone grafts, either by pretreating the graft or by immunosuppressing the recipient, were compared. Tibial grafts from B10.D2 mice, either untreated or pretreated in various ways, were transplanted into B10 recipients. The antibody response was followed and the extent of bone healing at 4 months was assessed. Pretreatment of the graft by X-irradiation, freezing, or by incubation in alloantisera (either anti-H-2 or anti-Ia) reduced or abolished the immunogenicity of the graft. Immunosuppression of the recipient with methotrexate or antilymphocyte serum (ALS) also greatly depressed the antibody response. But when healing was assessed, none of these treatments except ALS improved the delayed healing of the bone allografts. The reason for this failure was probably that X-irradiation, freezing, alloantiserum pretreatment, and methotrexate all interfered with bone healing directly, whereas ALS did not. We conclude that many methods will reduce the immune response to allogeneic bone, but that only ALS will improve the healing of the allogeneic bone. Furthermore, as a corollary to the observation that pretreatment with anti-Ia serum markedly reduced the immunogenicity of bone allografts, we conclude that much of the immunogenicity of bone allografts is attributable to a population of Ia-positive cells.

Effect of ethanol on taurine concentration in the brain

The taurine concentration in the brain was decreased in ethanol-dependent rats, but returned to normal soon after withdrawal of ethanol. It was not affected by acute ethanol administration.

Increase of brain taurine contents of E1 mice by physiological stimulation

We determined the effect of physiological stimulation on taurine contents in three regions (cerebral cortex, brain stem and cerebellum) of the brain of E1 mice, a genetically epileptic strain. Taurine contents in all regions of the brain increased significantly at the onset of convulsions, as induced by tossing the animals up many times. Levels in the cerebral cortex and cerebellum increased markedly in the early stage of the stimulation, yet convulsion did not occur. Taurine contents in the cerebral cortex and brain stem returned to the resting level with 30 min after the onset of convulsions, while levels in the cerebellum remained high for 3 hr. Concentration of taurine in the plasma also increased with the onset of convulsions. On the other hand, taurine administration increased the threshold of convulsion by the stimulation in E1 mice.

Circannual variation and genetic regulation of hepatic testosterone hydroxylase activities in inbred strains of mice

Hydroxylation of testosterone by hepatic microsomes at positions 6 alpha, 6 beta, 7 alpha, 15 alpha, and 16 alpha has been studied in C57BL/6J, 129/J, and A/J mice. Differences in hydroxylase activities between the C57BL/6J and A/J strains and between the C57BL/6J and 129/J strains were investigated using standard genetic breeding protocols. In the C57BL/6J X A/J line, 6 alpha- and 7 alpha-hydroxylase activity appeared to be under polygenic control in both sexes, as did 15 alpha-hydroxylase activity in females. The lack of 16 alpha-hydroxylase activity observed in 129/J females behaved as a recessive, autosomal, single locus, sex-limited trait. In several instances, the level of hydroxylase activity at one position appeared to be affected by the level of hydroxylase activity at a second position; however, no clear-cut pattern was discerned. Over a period of a year, a remarkable cycle in total hydroxylase activity for all mice was observed; the average activity was greatest in December and least in April.

Small bowel melaena: 2 cases diagnosed by angiography

Two cases of small bowel tumour presenting with melaena are reported. Selective visceral arteriography was found to be invaluable in the management of these cases. The first case presented with intermittent bleeding causing anaemia. Conventional barium studies of the small and large bowel revealed no abnormality. Superior mesenteric angiography revealed a mass lesion in the jejunum, with features characteristic of a leiomyoma. The second case presented with massive gastrointestinal bleeding. Selective visceral angiography was performed initially and revealed a large, mainly avascular, mass lesion in the ileum. Pathological examination showed a leiomyoma which had undergone cystic degeneration. The value of selective angiography in patients with suspected small bowel bleeding is discussed..

Effect of renal ischaemia in rats with obstructive jaundice

The ability of kidneys to withstand renal ischaemia has been tested in jaundiced and non-jaundiced rats. No significant difference could be demonstrated between the two groups of animals except that renal weight increased greatly in the presence of jaundice. Both jaundiced and non-jaundiced animals showed a median lethal dose of renal ischaemia of approximately 120 min when renal function was tested by delayed opposite nephrectomy. It was shown that a recent laparotomy renders the kidney more susceptible to renal ischaemia.

Comparison of aerosolized atropine sulfate and SCH 1000 on exercise-induced bronchospasm in children

The new anticholinergic compound Sch 1000 (ipratropium bromide) has been reported to be an effective bronchodilator without significant atropine-like side effects. We evaluated the effectiveness of different doses of nebulized Sch 1000 (40 microgram and 80 microgram) aerosolized atropine sulfate (1 mg) and placebo in the prevention of exercise-induced bronchospasm (EIB) in 20 children with atopic bronchial asthma. A random, crossover double-blind protocol was used. Standard exercise on a cycloergometer was used to induce EIB. Pulmonary function was determined before and after drug administration and exercise. Following no treatment or placebo, exercise resulted in average reductions of 33% to 43% in plethysmographic specific airway conductance (SGaw), of 20% to 25% in forced expiratory volume in 1 sec (FEV1), and of 25% to 32% in maximal midexpiratory flow rate. Exercise following no treatment or placebo resulted in average increases of 23% to 30% in thoracic gas volume (Vtg). Prior to exercise atropine and either dose of Sch 1000 caused significant increases in SGaw (48% to 59%). After pretreatment with Sch 1000 or atropine, exercise caused SGaw to fall to values that were not significantly different from pretreatment medication values, but were significantly higher than values following exercise without pretreatment or after pretreatment with placebo. No significant differences were noted between the effects of atropine and Sch 1000 on EIB. We conclude that at the doses used atropine and Sch 1000 cause equivalent degrees of bronchodilation but neither drug specifically inhibits EIB.

Volume-related mitochondrial deoxyribonucleic acid synthesis in zygotes and vegetative cells of Saccharomyces cerevisiae

The synthesis of mitochondrial deoxyribonucleic acid (DNA) in Saccharomyces cerevisiae cells has been examined during conjugation, in preconjugal conditions, and in control cultures that were not exposed to obverse diffusible sex factors. The ratios of mitochondrial to nuclear DNA varied from about 0.1 in control cells, to about 0.3 in alpha cells exposed for 180 min to cell-free culture medium from a cells, and to about 0.4 in conjugating cells 150 min after mixing. The enhanced levels of mitochondrial DNA during preconjugal and conjugal conditions seem correlated with enhanced cell volumes. Likewise, amounts of mitochondrial DNA in vegetative cells were found to be correlated with cytoplasmic volumes.

Analysis of HeLa cell hypoxanthine phosphoribosyltransferase mutants and revertants by two-dimensional polyacrylamide gel electrophoresis: evidence for silent gene activation

The spot corresponding to hypoxanthine phosphoribosyltransferase (HPRT; IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8) has been identified in two-dimensional polyacrylamide gels of HeLa cell extracts. This spot is absent in gels of 24 HPRT dificient mutants. A missense mutant displays a new HPRT spot at the same molecular weight but different isoelectric focusing position. Five independently isolated revertants of the missense mutant display spots corresponding to both the wild-type and mutant proteins indicating that they synthesize HPRT from two separate genes. If the missense protein is synthesized from a mutated form of the initially active HPRT gene, then wild-type HPRT protein in the revertants must be snythesized from a newly activated but prevously silent wild-type gene. The newly activated gene in the revertants of the missense mutation appears unstable producing a high frequency of spontaneous HPRT mutants.

A study of HL-A types in Rh haemolytic disease of the newborn

The HL-A types of 288 women, immunised to the Rh(D) antigen as a result of pregnancy, have been compared to the HL-A types of 139 women who although they have had Rh(D)-positive children have not produced anti-Rh(D). There is an indication that an increased incidence of the HL-A3 antigen is associated with the immunised mothers. A study of the HL-A types of husbands and children of both immunised and non-immunised women did not suggest that their HL-A types played a significant role in anti-Rh(D) production. The frequencies of the HL-A antigens in each category studied have been tabulated for record purposes, as well as the frequencies in a random panel of persons living in the Newcastle environs. Full ABO, Rh and HL-A details of 50 immunised mothers and their families and of 58 non-immunised mothers and their families are available.

Unusual clonal evolution in a case of chronic myelogenous leukemia

Several unusual cytogenetic changes have occurred during the evolution of chronic myelogenous leukemia in a 32-year-old white male with this disease for 8 years. The first appearance of a hypodiploid cell line containing a dicentric marker occurred 2 years after diagnosis and this line was eliminated by several courses of therapy with hydroxyurea. A second clone, which had a partial deletion of the long arm of one of the number 8 chromosomes (8q-) was noted a year later, but this line has been refractory to intensive combination chemotherapy.

Superiority of conventional intrathecal methotrexate therapy with maintenance over intensive intrathecal methotrexate therapy, unmaintained, or radiotherapy (2000-2500 rads tumor dose) in treatment for meningeal leukemia

In the treatment of patients with meningeal leukemia, conventional intrathecal methotrexate therapy followed by maintenance intrathecal methotrexate at intervals of 8 weeks has been shown superior to an intensive, unmaintained intrathecal methotrexate induction regimen, and to neuroaxis radiotherapy, tumor dose 2000-2500 rads. In each of the treatment regimens, all children completing proscribed therapy achieved complete CNS remission as judged by the return of CSF findings to normal. Median lengths of remission were: maintenance regimen 240 days; intensive induction regimen, 106 days; and radiotherapy, 216 days. Differences were of statistical significance between the maintenance regimen and the intensive regimen (p equal 0.001), and between the radiotherapy and intensive regimens (p equal 0.01). Maintenance intrathecal therapy appeared to affect favorably the duration of existing marrow remissions; the median time to marrow relapse for patients given maintenance therapy was significantly longer than for those given intensive induction therapy. Toxicity of the chemotherapy regimens was not prohibitive. Radiotherapy was associated with severe myelosuppression, interruptions of systemic therapy, and serious infections, which resulted in death in five children.

Split ileostomy in the treatment of Crohn's disease of the colon

Because of the problems associated with surgical resection of Crohn's disease of the colon a more conservative approach has been used in Oxford since 1960. The inflamed large bowel has been defunctioned by an external diversionary ileostomy and subsequently the disease has been treated with topical and oral corticosteroids. The technique of the split ileostomy used for this purpose is described and the indications for the operation and early results of its use in 69 patients are recorded. In carefully chosen cases the method has two advantages over primary resection. In some patients the inflammation improved sufficiently for continuity of the bowel to be restored without resection being necessary and without medical treatment being required. In others the ileostomy resulted in a marked improvement in general health which has made the subsequent major resection a safer procedure. As an extension of the technique the use of an external faecal diversion by ileostomy is recorded in a further 11 patients who had a synchronous resection of a segment of bowel affected by Crohn's disease.

Acute appendicitis complicating pregnancy in the Oxford region

A study of 75 patients who were admitted to the Oxford group of hospitals with suspected acute appendicitis during pregnancy is presented, and the findings are compared with those in a similar group of non-pregnant patients. In general the disease was found at operation to be more advanced in the pregnant group, and this was probably a reflection of a delay in diagnosis. This delay, which was seen most commonly in the third trimester, led to a number of fetal deaths which might have been avoided by earlier operation. Furthermore, the dangers resulting from a negative laparotomy were sufficiently minor for a policy of early surgery for suspected acute appendicitis to be advocated during all stages of pregnancy.

The effect of obstructive jaundice on the migration of reticulo-endothelial cells and fibroblasts into early experimental granulomata

Clinical and experimental evidence indicates that obstructive jaundice inhibits the healing of wounds. Experiments in the rat designed to investigate the migration of reticulo-endothelial and fibroblasts into experimental granulomata are described. Standard preparations of obstructive jaundice and controls were devised using Wistar rats. The effects of bile-duct obstruction and sham ligation are described. In another group of animals which was similarly prepared granuloma-pouch experiments were carried out by burying sterile cotton-wool pledgets of a known weight. These peledgets were removed from the jaundiced and control animals on the third, fifth, seventh, and ninth days after implantation, dried to remove the fluid component of the inflammatory process, and weighed on a microbalance. The weights were compared and it was found that a significant inhibition of weight increase occurred in the jaundiced animals during the first week, suggesting a delay in the migratory activity of reticuloendothelial cells and fibroblasts.

The effect of experimental bile-duct obstruction on critical biosynthetic functions of the liver

Using biosynthetic activities which have a maximum energy requirement, the effect of obstruction of the bile-duct has been studied in isolated perfused rat livers, and compared with controls undergoing “sham” ligation and with normal animals. The maximum rate of gluconeogenesis from lactate was inhibited by 67 per cent after bile-duct ligation when compared with the normal value. The maximum rate of urea synthesis which occurred in the presence of ornithine was the same in the jaundiced and in the normal animals. ‘Sham’ operation, without ligation of the bile-duct, inhibited gluconeogenesis by less than 20 per cent but doubled the maximum rate of urea synthesis.

It is concluded that complete biliary obstruction seriously impairs gluconeogenesis and prevents the normal increase of urea synthesis which occurs in response to trauma and that these changes develop earlier than might be expected after the onset of obstruction.

Some possible mechanisms of these effects are discussed. If similar abnormalities of hepatocyte function are demonstrated in man it is suggested that surgical relief of obstructive jaundice is indicated at an early stage.