Temperature-sensitive mutants of herpes simplex virus type 2: description of three new complementation groups and studies on the inhibition of host cell DNA synthesis.

Three new complementation groups of type 2 herpes simplex virus are described bringing the total number of complementation groups characterized to 13. Of the three new groups, ts 11 fails to make virus DNA at non-permissive temperature (38 degrees C) whereas ts 12 and ts 13 synthesize only very small amounts of virus or cellular DNA at 38 degrees C. ts 11, like ts 9 (Halliburton & Timbury, 1973) fails to switch off host cell DNA synthesis at 38 degrees C. That this is a failure to switch off cell DNA rather than a stimulation of cell DNA synthesis was confirmed in experiments using resting cells. Both the inability to make virus DNA and the inability to switch off cell DNA are reversed in temperature shift-down experiments with cells infected with ts 9 or ts 11. In temperature shift-up experiments, cellular DNA synthesis is inhibited after the shift but virus DNA is only made in very small amounts, probably due to the continuing functioning of a protein made at permissive temperature (31 degrees C) before the shift but which cannot be made at 38 degrees C. The shift-down experiments and the fact that ts 9 and ts 11 complement one another, suggest that the switch-off of host cell DNA synthesis may involve more than one virus specified function. U.v. irradiated virus fails to switch off host cell DNA synthesis.


Interaction of mouse peritoneal macrophages with fixed rabies virus in vivo and in vitro.

The resistance of mice to intraperitoneal and intramuscular infection with fixed rabies virus increases with age. Treatment of mature animals with either silica, indian ink or antimacrophage serum, which are cytotoxic for macrophages, reduced their resistance to intraperitoneal, but not to intramuscular or intracerebral infection. Transfer of peritoneal macrophages from adults to syngeneic suckling mice delayed but did not prevent mortality from intraperitoneal infection: transfer of peritoneal macrophages to intramuscular sites of infection did not protect adult mice. Rabies virus was phagocytosed by peritoneal macrophages in culture but neither replicated nor induced interferon. Evidence of active intracellular destruction of virus was obscured by thermal inactivation at 37 degrees C. Less inactivation occurred at 33 degrees C. Infected macrophages from suckling mice, but not those from adult mice, spread infection to susceptible cells.


Analysis of herpesvirus DNA substructure by means of restriction endonucleases.

The mol. wt. and molar ratios of the Hind III and Hpa I fragments of HSV-1 DNA and the Eco RI fragments of HSV-2 DNA have been determined. Results obtained suggest that DNA isolated from both HSV-1 and HSV-2 consists of molecules with four different sequence arrangements which are present in similar amounts. Our explanation of the cleavage patterns of these four genome arrangements with the different restriction enzymes is presented. Some of the possible implications of these four genome arrangements for genetic recombination are discussed.


Transformation of human embryonic fibroblasts by photodynamically inactivated herpes simplex virus, type 2 at supra-optimal temperature.

Infection of human embryonic fibroblast cell monolayers with neutral red and light-inactivated herpes simplex virus, type 2 (HSV-2) at supra-optimal temperature (42 degrees C) resulted in persistence of viable cells in suspension culture at 37 degrees C which have properties in common with virus transformed cells: formation of cell aggregates, HSV-2-specific antigens and colony formation in soft methyl cellulose medium. These data are consistent with the idea that photodynamic inactivated HSV-2 has potential oncogenic activity.


Different patterns of polyadenylation of rhinovirus: specified RNA during multiplication in human aneuploid and diploid cells.

The polyadenylation of rhinovirus-specified RNA in aneuploid HeLa cells and diploid human embryo lung (HEL) cells has been investigated. Polyadenylation occurs at a faster rate and more extensively to virus-specified RNA in infected HEL cells compared with HeLa cells. Poly(A) is added post-transcriptively in both cell types. Furthermore the addition of adenosine or poly(A) during virus multiplication increases the polyadenylation of virus single-stranded RNAs in both cell types, but to a greater extent in HeLa cells.


Monosynaptic reflexes in the superficial forearm flexors in man and their clinical significance.

Indirect motor responses with the characteristics of the H wave were recorded from the flexor carpi radialis and the palmaris longus muscles in normal adults. A series of experiments has been performed, constituting circumstantial arguments for the monosynaptic nature of these reflex responses. The findings in pathological conditions, which corroborated this point of view, are documented briefly.


Ischaemic infarct of the brain stem combined with bisymptomatic Klippel-Trénaunay-Weber syndrome and cutis laxa.

The combination of Klippel-Trénaunay-Weber syndrome (KTWS) with intracranial vascular malformations is documented by angiography in a 25 year old man with the classical features of KTWS: systematized naevi, hypertrophy of the right side, and varicosis. In addition, the syndrome was associated with "cuts laxa", a coincidence of somar rarity. The patient suffered from an ischaemic infarct of the brain stem with several neurological deficits.


Unusual manifestations of herpes zoster. A clinical and electrophysiological study.

The literature on complicated herpes zoster is summarized in this paper. The case histories of 18 patients with herpes zoster are presented. Two patients had encephalitis, 2 had myelitis and the other 14 patients had various types of lower motor neurone disturbance. Both patients with encephalitis--one of who developed choreo-athetosis during the illness--recovered fully. Only 1 of the 2 patients with myelitis recovered fully; the other remains severely paraparetic and the reason for her incomplete recovery may be related to the presence of generalized arteriolar disease associated with seronegative rheumatoid disease. One patient developed a Guillain-Barre syndrome 3 weeks after the onset of herpes zoster. Recovery in the 15 patients with lower motor neurone involvement has been slow butcomplete--or almost complete--in all but 1, a patient with persistent facial weakness as part of the Ramsay Hunt syndrome and who also had weakness of one upper limb. Seven other patients had lower limb weakness. In 2 patients the weakness was confined to abdominal myotomes and 2 other patients had urinary retention. Electromyographic abnormalities were found in the muscles which were weak and  frequently also in muscles which appeared strong. It is emphasized that neurological disturbances other than sensory abnormalities may be found in patients with herpes zoster. Motor complications of various types are not uncommon.


Dysmyelination in the sciatic nerves of dystrophic mice.

Ultrastructural alterations were observed in the sciatic nerve of dystrophic mice. Myelin sheaths were abnormal in shape, abruptly ceased beyond a node of Ranvier, leaving the axon naked. These changes were seen in both afferent and efferent nerve fibres. Apparent embryonal Schwann cells and Schwann cells which were associated with increased lysosomes in the cytoplasm were observed in the proximal portion. There is a relative decrease in Schwann cells in the cross-section of the radicular parts, and a relative increase in the distal parts. The mean number of neurotubules per unit area was smaller while the mean number of the neurofilaments was larger in U-axons, in the dystrophic mice than in the controls. In M-fibres, neurotubules and neurofilaments showed no significant difference between systrophic and control mice.


Probability of conduction deficit as related to fiber length in random-distribution models of peripheral neuropathies.

This paper presents a set of probabilistic models which reproduce the proximodistal gradient of sensory deficit in peripheral neuropathies, on the basis of the occurrence of axonal dysfunction as a result of randomly distributed abnormalities. The models, which are based on conduction block, loss of temporal coherence, and weak interactions between nerve fibers, demonstrate that randomly distributed axonal dysfunction provides a sufficient condition for distal sensory deficit. The models predict a marked reduction in the length for normal sensory conduction with small increases in the probability of axomal dysfunction, providing a possible correlate for the rapid clinical progression of some neuropathies. The hypothesis that weak interactions between fibers result in paresthesiae in peripheral neuropathies is also discussed.


Relative strength of synaptic input from short-latency pathways to motor units of defined type in cat medial gastrocnemius.

1. Intracellular recording and stimulation techniques were used in anesthetized cats to study the interrelations between amplitudes of PSPs produced by electrical stimulation of several short-latency pathways to MG alpha motoneurons and the mechanical properties of muscle units innervated by the same cells. Motor-unit types were identified by muscle-unit properties.2. The maximum amplitudes of monosynaptic EPSPs produced in MG motoneurons by activation of homonymous (MG) and heteronymous (LGS) group Ia afferents were clearly related to motor-unit type, being, on the average, largest in type S units, somewhat smaller in type FR and F(int) units, and smallest in type FF units. Correspondingly, group Ia EPSP amplitudes were inversely correlated with muscle-unit tension production and directly correlated with resistance to fatigue. The same input distribution was true for disynaptic IPSPs produced by group Ia afferents from antagonist ankle flexors.3. The amplitudes of monosynaptic EPSPs produced by fibers descending in the ipsilateral ventral funiculi of the low thoracic cord were not clearly related to MG motor-unit type or (therefore) to muscle-unit properties.4. A quantitative input-output model of the MG motor-unit pool, based in part on the present results, suggests that overall characteristics of MG motor units, and their relative numbers in the MG pool, reflect functional specializations determined by specific mechanical demands placed on the MG muscle by the usual motor behavior of the animal.


Rhythmic hyperpolarizations and depolarization of sympathetic ganglion cells induced by caffeine.

Superfusion of the isolated sympathetic ganglion of the bullfrog with a caffeine-containing (1-6 mM) solution caused in many cells an initial slow hyperpolarization which was followed by a subliminal depolarization interruped by rhythmic hyperpolarizations. A hyperpolarization, similar to one of the rhythmic hyperpolarizations, could be triggered by an action potential in the presence of caffeine. The action potential itself was not markedly affected by caffeine except for its afterhyperpolarization which was prolonged. All these caffeine-induced hyperpolarizations were associated with a marked reduction of the membrane resistance, their amplitude was increased in a K+-free solution and decreased in a high-K+ solution, and their polarity was reversed at the same level at which the afterhyperpolarization was also inverted. This reversal level was not altered by omission of Na+ or C1- from the external medium. These hyperpolarizations were reversibly abolished by depletion of external Ca2+ or replacement of external Ca2+ by Mg2+. Excess of external Ca2+ caused a shortening of the interval between rhythmic hyperpolarizations. Furthermore, iontophoretic injection of EDTA into the cytoplasm markedly depressed the initial caffeine hyperpolarizatin and abolished both the rhythmic and evoked caffeine hyperpolarizations. The caffeine-induced depolarization was not affected by omission of external Cl-. It was decreased in a Na+-free medium, but completely eliminated by omission of both Na+ and Ca2+ from the external medium. Tetrodotoxin did not impair the production of the initial and the rhythmic hyperpolarizations. A strong depolarizing pulse could evoke a typical hyperpolarizing response in the presence of this compound. Dibutyryl cyclic AMP, d-tubocurarine, atropine, and phenoxybenzamine were without effect on the caffeine-induced hyperpolarizations and depolarization. It was concluded that each caffeine-induced hyperpolarization is the result of an increased K+ permeability, which is probably caused by a rise in the internal Ca2+ concentration. It was also concluded that the caffeine-induced depolarization is due to an increased membrane permeability to Ca2+ and Na+.


Assessment of effect of starvation, glucose, fatty acids and hormones on alpha-decarboxylation of leucine in skeletal muscle of rat.

The present investigations of rates of oxidation of [U-14C] or [1-14C]leucine by homogenates of gastrocnemius muscle of fed and starved rats have indicated that 14CO2 production is mainly the result of alpha-decarboxylation of leucine in this tissue. This incomplete oxidation was not the result of imparied tricarboxylic acid cycle since the oxidation of palmitate proceeded to completion within the experimental conditions. In the subsequent studies, the effect of altered nutrition and metabolic factors on alpha-decarboxylation of leucine by gastrocnemius muscle homogenates was investigated. Starvation increased the rate of alpha-decarboxylation of leucine. Glucose or palmitate (C16) added in physiological concentrations to the incubation medium were without effect on decarboxylation of leucine, but this reaction was stimulated by addition of 1 mM hexanoate (C6) or octanoate (C8) to the incubation medium. However, when fatty acid chain length was elongated to C10 (decanoate), the stimulatory effect was not only abolished, but this fatty acid significantly inhibited the rate of leucine decarboxylation. Addition of insulin, epinephrine, glucagon and cyclic AMP within a wide range of concentrations to the incubation medium did not significantly affect the rate of decarboxylation of leucine. These studies indicate a complex interrelationship between the metabolism of leucine and that of fatty acids.


Rat strain differences in cyclic-AMP levels in liver and epididymal fat pad tissue as influenced by glucagon.

A glucagon-saline solution (0.1 ml, 10(7) mole/100 g body weight) was injected via the portal vein into nonfasted Wistar and carbohydrate-sensitive BHE rats. Levels of liver and epididymal fat pad cyclic-AMP were observed after 6 and 24 minutes. When compared to sham injected rats at 6 minutes, glucagon injected rats of both strains had twice the level of cyclie-AMP in liver and fat pad tissue. By 24 minutes, the cyclic-AMP levels of the Wistar rats had decreased to those observed in their sham injected counterparts, and the concentration of liver cyclic-AMP in both sham injected and glucagon injected BHE rats had decreased to levels significantly below those observed in the Wistar rats. This observation suggests that a lipolytic-lipogenic imbalance may reside in the livers of rats of the BHE strain.


Urinary proteins in occupational exposure to chemicals and in diseases.

Isoelectric focusing in thin-layer polyacrylamide gel is a method with high resolving power, e.g. for urinary proteins. Therefore more information can be obtained with this method than with ordinary electrophoresis. The present version of the method has a high capacity and allows study of up to 25 samples in parallel on each gel. Only a little more than one hour is required for separation. A sensitive staining procedure is used which allows detection of as little as 0.1 mug of protein in each zone. When effects on the kidney are present more than 20 different protein zones can sometimes be separated. Evaluation is made by densitometry as well as by comparison and classification of patterns. Urine samples have been studied from workers with varying exposure to cadmium lead and various chlorinated hydrocarbons, and patients with glomerulonephritis, pyelonephritis, nephrosis and mixed tubular and glomerular diseases. Typical tubular patterns, i.e. as developed in association with cadmium exposure were characterized by elevated excretion of beta1-microglobulin. Other types of kidney malfunction showed different features.


Arteriography in oral and maxillofacial surgery.

A brief review of the methodology of selective external carotid arteriography is presented together with its risks, complications, and contraindications. The indications for this procedure are described with illustrative case material to demonstrate its usefulness in both diagnosis and preoperative evaluation of various types of lesions of the head and neck that may be encountered in the practice of oral and maxillofacial surgery.


Hepatitis type A in an oral surgeon: a prospective study of contacts.

No acute cases of clinical or anicteric hepatitis were in observed in 75% of 161 patients who had been exposed to hepatitis A by an oral surgeon during the contagious period. Three cases of liver dysfunction of indeterminate cause did occur, although at least two could be attributed to multiple abuses of drugs 3-5 and not to exposure to hepatitis. The fact that hepatitis A did not spread in this instance suggests that oral surgeons who are ill with acute hepatitis A do not necessarily transmit the disease to their patients. Epidemiologic investigations of similar situations will undoubtedly augment this preliminary data.


Melanotic neuroectodermal tumor of infancy.

A case of pigmented neuroectodermal tumor (melanotic progonoma) of the maxilla is presented. The treatment of this tumor is conservative surgical excision since the likelihood of recurrence is extremely slight. No case has ever been reported in which tumor metastasized.


Histopathologic study of the liver in the early cholestatic phase of alpha-1-antitrypsin deficiency.

Liver biopsies obtained during the first six months of life were studied in 15 children who had prolonged neonatal cholestasis and alpha-1-antitrypsin deficiency (Pi ZZ). Intracellular PAS-positive globules were always observed, even during the first months of life. At this early stage of the disease, three morphologic patterns of hepatic alteration were distinguished. Group 1: six cases with cholestasis, hepatocellular damage, and slight portal fibrosis; Group 2: five cases with important portal fibrosis and bile duct proliferation; and Group 3: four cases in which ductular hypoplasia was the main feature. A correlation between histologic patterns and clinical course may be established: improvement of liver injury in Group 1, early cirrhosis in Group 2, and prolonged cholestasis in Group 3. The natural evolution of the disease appears to be different in each of the three groups.


Enzymatic penetration through intact sulcular epithelium.

To explore possible enzymatic penetration through intact sulcular epithelium tritium labeled hyaluronidase and collagenase were applied to the gingival sulcus of five white lip marmosets. One quadrant per monkey remained untreated. Each remaining quadrant was randomly assigned to one of the following modalities of application: (a) tritiated hyaluronidase, (b) tritiated collagenase, (c) unlabeled hyaluronidase followed by tritiated collagenase, (d) inactivated tritiated hyaluronidase, or (e) normal saline as experimental controls. The enzymes were applied by means of a Pasteur disposable pipette. Eight drops were administered over a 4-minute period, one every 30 seconds. After a 5-minute waiting period a second series of eight applications was given over a 4-minute period. Radioautographic and standard histologic materials were obtained. Results suggest that: 1. Hyaluronidase has the ability to penetrate through intact nonkeratinized sulcular epithelium, widening the intercellular epithelial spaces and disorganizing the connective tissue ground substance. 2. Collagenase per se does not have the ability to penetrate through the intact sulcular epithelium. Its effect remains confined only to the superficial layers of the epithelium. 3. However, when collagenase application is preceded by hyaluronidase, collagenase spreads easily through the epithelium and deeply into the connective tissue. Hyaluronidase acts unquestionably as a spreading factors.


Studies on tolerance development to single doses of morphine in mice.

Single-dose tolerance to the antinociceptive effect of morphine can be demonstrated using an adequate initial priming dose of morphine and allowing an interval of 48 to 72 hours for its development. The threshold dose necessary to produce tolerance was found to be about 3 to 4 times greater than that for producing analgesia but higher doses of morphine did not enhance further tolerance development. Evidence of tolerance was indicated by the fact that when the antinociceptive response to morphine was assessed by the hot-plate and the tail-flick procedures, a shift in the dose-response curve of morphine to the right occurred after an adequate single priming dose of morphine. Cross-tolerance was evidenced by a decrease in analgetic response to methadone 3 days after a single priming dose of morphine and a decrease in morphine response after a single dose of methadone. The development of single-dose tolerance was inhibited by cycloheximide. Single-dose tolerance was also blocked by 5,6-dihydroxytryptamine and perhaps enhanced by L-tryptophan. Cyclic 3',5'-adensine monophosphate did not affect single-dose tolerance development significantly although the direction was in favor of augmentation. Morphine uptake by the brain was not modified by the development of single-dose tolerance. Physical dependence, as measured by naloxone-precipitated withdrawal jumping, was not observed when single-dose analgetic tolerance was maximal. The results suggest that single-dose tolerance to morphine involves the synthesis of some macromolecule and support previous findings in this laboratroy involving an association with serotonin.


Regulation of cyclic nucleotide levels and glycogen phosphorylase activity by acetylcholine and epinephrine in perfused rat hearts.

Acetylcholine (ACh) produced a time and dose-dependent increase in cyclic 3',5'-guanosine monophosphate (cyclic GMP) levels in perfused rat hearts without any significant (P greater than .05) change in cyclic 3',5'-adensoine monophosphate (cyclic AMP) level or glycogen phosphorylase activity. Epinephrine produced a dose-dependent increase in both cyclin AMP and phosphorylase activity but no significant (P greater than .05) change in cyclic GMP levels. When ACh (10(-6) M) was infused into hearts during the infusion of epinephrine (10(-6) M), a time-dependent increase in cyclic GMP and decrease in cyclic AMP occurred, both of which preceded a significant (P less than .05) decrease in glycogen phosphorylase activity. In epinephrine-stimulated hearts, ACh produced a dose-dependent increase in cyclic GMP levels. Similar concentrations produced a fall in cyclic AMP levels and phosphorylase activity. No condition tested resulted in a significant (P greater than .05) change in glycogen synthase activity. It is concluded that ACh can reduce cyclic AMP levels and phosphorylase activity only when they have been elevated above basal values. These changes are associated with an increase in cyclic GMP. The reduction in phosphorylase produced by ACh may be the result of either or both of the changes in cyclic nucleotide levels.


Blockade by amino acid antagonists of neuronal excitation mediated by the pyramidal tract.

1. The responses to glutamate and amino acid antagonists of cells in the cuneate nucleus of anaesthetized rats have been examined.2. 1-hydroxy-3-amino-pyrrolidone-2 (HA-966) and glutamic acid diethylester applied by micro-iontophoresis reduced glutamate excitation of the neurons. HA-966 WAS EFFECTIVE ON MORE CELLS THAN GLUTAMIC ACID DIETHYLESTER AND WAS MORE POTENT. HA-966 DID NOT AFFECT EXCITATORY RESPONSES TO ACETYLCHOLINE.3. Spike activity of cuneate cells was evoked by stimulating the cerebral cortex. Spikeswhich could be attributed to monosynaptic activation of the cells were studied. The pyramidal tract is the only corticofugal pathway known to be capable of short latency activation of dorsal column nucleus neurones.4. HA-966 reversibly blocked the evoked activity in twenty-eight (70%) of forty units in which monosynaptically evoked spikes were induced.5. The results raise the possibility that the neurotransmitter released by neurones of the pyramidal tract may be an excitatory amino acid.


Cholinergic motor neurones in the stomatogastric system of the lobster.

1. A study of the neurotransmitters used by each of the eleven types of excitatory motor neurones (identified according to the muscle innervated) of the lobster stomatogastric ganglion was undertaken. 2. The dorsal dilator muscle is innervated by the two motor neurones designated 'PD'. Bath and iontophoretic applications of acetylcholine (ACh) produce contractures and depolarizations respectively in the dorsal dilator muscle. 3. Pharmacological experiments support the cholinergic nature of the excitatory junctional potentials (e.j.p.s) recorded in the dorsal dilator muscle when the PD motor nerve is stimulated. 4. The apparent reversal potentials for the e.j.p.s and the iontophoretic ACh response in the dorsal dilator muscle are the same. 5. On the basis of choline acetyltransferase assays on identified stomatogastric ganglion motor neurone somata and tension measurements on the muscles innervated by each type of stomatogastric ganglion motor neurone, a transmitter candidate was established for each type of motor neurone. Motor neurones named VD, LPG, GM, MG, LG, and DG are putatively cholinergic. L-Glutamate is a transmitter candidate for the motor neurones called LP, PY, IC, and AM. 6. Potential correlations between the distribution of putatively cholinergic and glutaminergic motor neurones and the electrical coupling among the stomatogastric ganglion motor neurones are discussed.


Mode of stimulation by adenosine 3':5'-cyclic monophosphate of the sodium efflux in barnacle muscle fibres.

1. Giant fibres of the barnacle Balanus nubilus have been used as a preparation for studying the mode of action of cAMP on sodium transport. 2. It is shown that a concentration of cAMP as low as 10(-6)M, when micro-injected, causes a sharp rise in the radio-Na efflux. Ouabain fails to reverse the cAMP effect. 3. The magnitude of the response of the Na efflux to cAMP is markedly reduced by pre-injecting 100 or 500 mM-EGTA solutions or by omitting Ca2+ from the bathing medium. Both together fail to bring about a greater reduction in the response. 4. The response to cAMP is greatly reduced by pre-injecting the protein inhibitor of Walsh and practically abolished by pre-injecting 500 mM-EGTA and soaking in Ca-free artificial sea water, ASW. 5. The Ca2+-independent component of the Na efflux which is also stimulated by cAMP is shown to involve Na for H exchange. The magnitude of this exchange is governed by external pH. 6. The Na efflux into Ca2+-free, Li+-ASW is shown to be markedly stimulated by injecting cAMP, an effect which is enhanced by reducing external pH. 7. The Na efflux at 0 degrees C is stimulated by injecting cAMP. This is shown to be related to activation of the protein kinase by cAMP and to depend on the presence of external Ca2+. 8 (i) Ethacrynic acid when injected reduces the ouabain-insensitive Na efflux into HEPES-Ca2+-free ASW at pH 6-3. These same fibres show a marked response to cAMP. (II) The ouabain-insensitive Na efflux into HCO3-, Ca2+-free ASW from fibres pre-treated with ethacrynic acid fails to respond to external acidification. This is interpreted as indicating that ethacrynic acid inactivates the CO2-sensitive adenyl cyclase system. These same fibres when injected with cAMP show a marked response. (iii) Stimulation of the ouabain-insensitive Na efflux into HCO-3, Ca2+-free ASW by external acidification is reversed by injecting ethacrynic acid. These fibres when injected with cAMP show a reduced response. 9. It is concluded that: (i) stimulation of the Na efflux by injected cAMP is mainly due to activation of cAMP-dependent protein kinase; (ii) the underlying exchange mechanism consists of Na:Ca and Na:H exchange. Interaction of Ca2+ with a phosphorylated membrane, thereby modifying permeability remains as a real possibility; (iii) the site of action of CO2 and ethacrynic acid is the adenyl cyclase system. 10. The implications of activation of the adenyl cyclase system by CO2 and Na:H exchange are briefly touched upon.


The effect of calcium ions on the binomial statistic parameters that control acetylcholine release at preganglionic nerve terminals.

1. A study has been made of the effects of changing [Ca]O and [Mg]O on the binomial statistic parameters p and n that control the average quantal content (m) of the excitatory post-synaptic potential (e.p.s.p.) due to acetylcholine release at preganglionic nerve terminals. 2. When [Ca]O was increased in the range from 0-2 to 0-5 mM, p increased as the first power of [Ca]O whereas n increased as the 0-5 power of [Ca]O; when [Mg]O was increased in the range from 5 to 200 mM, p decreased as the first power of [Mg]O whereas n decreased as the 0-5 power of [Mg]O. 3. The increase in quantal release of a test impulse following a conditioning impulse was primarily due to an increase in n; the increase in quantal content of successive e.p.s.p.s in a short train was due to an increase in n and p, and the increase in n was quantitatively described in terms of the accumulation of a Ca-receptor complex in the nerve terminal. 4. The decrease in quantal content of successive e.p.s.p.s during long trains of impulses over several minutes was primarily due to a decrease in n. These results are discussed in terms of an hypothesis concerning the physical basis of n and p in the release process.


Induction of cholinergic enzymes in chick ciliary ganglion and iris muscle cells during synapse formation.

1. In chick ciliary ganglia and irises, cholineacetyltransferase (ChAc) and acetylcholinesterase (AChE) activities were measured from the fifth day of incubation until 1 week after hatching. The changes in enzyme activity were correlated in time with previous electrophysiological and morphological findings of synapse formation in these tissues. 2. At Stage 26 (Hamburger & Hamilton, 1951; before synapse formation in the ganglia) low activities of ChAc (12 +/- 4 [mean +/- S.E.] p-mole of ACh synthesized/hr) were measured in the iris nerve terminals, indicating that ganglion cells are biochemically differentiated, immediately after cell migration is completed. The specific acitivities of ChAc and AChE rose during development and these increases were closely related to the onset and maturation of ganglionic and iris synaptic transmission. These increases in enzyme activities can be used in cholinergic synapses as an index of synapse formation. 3. The 200-fold specific increase of ChAc in iris nerve terminals which occurs at Stage 34 probably reflects an increase in synthesis of the enzyme in ganglion cells and suggests that the formation of the iris neuromuscular junction triggers the enzyme induction. It is implied that the cell responds to a signal ascending the axon from the terminal. 4. The initial increase of AChE specific activity in the ganglion occurs after transmission is established in all cells between Stage 30 and 34 and is mainly due to enzyme synthesis by the ganglion cells. In the iris there is a twofold increase in specific activity after the formation of neuromuscular junctions which probably reflects enzyme induction in the muscle subneural region. It is concluded that the specific induction of AChE in post-junctional cells is due to an influence of the prejunctional element. 5. During synaptic formation in the ciliary ganglion, reciprocal interactions between the neurones and their targets result in the induction of ChAc in the prejunctional elements and AChE in the post-junctional cells.


Input-output relation of transmission through cuneate nucleus.

1. In decerebrate cats, micro-electrodes were inserted into the cuneate nucleus to stimulate afferent terminals with single shocks of varying intensities. Estimates of the input and output of the nucleus were obtained by integrating antidromic responses in forelimb cutaneous nerves and orthodromic responses in the medial lemniscus. 2. Input-output curves were normally very non-linear, reflecting the high synaptic potency of small inputs. They were fitted readily by power functions, with exponents averaging 0-50. 3. The normal input-output relation rapidly disappeared after interruption of the blood supply. A loss of synaptic efficiency of small inputs was indicated by curves with exponents of greater than or equal to 1; this was associated with a sharp increase in terminal excitability. 4. Within the range of surface temperature 30-40 degrees C, warming made the input-output curves steeper but reduced terminal excitability, whereas cooling had the opposite effect. The efficiency of transmission was thus inversely correlated with terminal excitability. 5. The non-linear shape of cuneate input-output curves is probably not determined by inhibitory control, since picrotoxin depressed rather than enhanced outputs. 6. On the other hand, pentobarbitone made the input-output curves markedly steeper and tended to lower terminal excitability.


On the elementary conductance event produced by L-glutamate and quanta of the natural transmitter at the neuromuscular junctions of Maia squinado.

1. The membrane potential of giant muscle fibres of Maia squinado was measured with an intracellular wire electrode. On applying L-glutamate to the fibre the cell deplorized and fluctuations of the membrane potential around its mean level--glutamate noise--were seen. 2. The variance of the glutamate voltage noise is proportional to the mean level of depolarization. The noise can be regarded as being caused by numerous exponentially decaying elementary voltage events about 5 X 10(-10) V in amplitude. The miniature excitatory junctional potential (min.e.j.p.) is approximately 6000 times the amplitude of the elementary voltage event produced by L-glutamate. 3. The power spectrum of glutamate voltage noise is a Lorentzian with a half-power frequency of approximately 20 Hz. 4. Min. e.j.p.s. decay exponentially with a time constant that coincides with the average lifetime of the elementary glutamate voltage event. 5. When glutamate is applied locally to a spot where extracellular min. e.j.p.s. can be recorded with a focal glass pipette, extracellular glutamate noise is seen. Glutamate noise could not be detected from elsewhere on the fibre. 6. The variance of the extracellular noise is proportional to the mean extracellular potential, and its power spectrum is a Lorentzian with a half-power frequency of about 110 Hz. 7. The extracellular min. e.j.p.s decay exponentially with a time constant that coincides with average lifetime of the elementary glutamate current event. 8. It is suggested that the decay of the quantal currents flowing at the excitatory junction is limited by the closure of the conductance channels in the post-synaptic membrane and not by the relaxation of the transmitter concentration in the synaptic cleft.


A comparison of the presynaptic and post-synaptic actions of pentobarbitone and phenobarbitone in the neuromuscular junction of the frog.

1. Pentobarbitone or phenobarbitone, in increasing concentrations up to 0-5 mM, progressively reduced the amplitude of miniature end-plate potentials (min.e.p.p.s). Pentobarbitone was the more potent of the two barbiturates in this regard. 2. Both barbiturates produced a monotonic increase in mean quantum content of the end-plate potential (e.p.p.) with increasing concentrations up to 0-5 mM. Pentobarbitone and phenobarbitone were equally potent in their action on evoked transmitter release. 3. The effect, if any, of increasing concentrations of barbiturates on the e.p.p. amplitude was depression. Therefore, over the range of concentrations examined the enhancement of transmitter release was quantitatively less than the reduction in responsiveness of the post-synaptic membrane. 4. Because of the greater ratio of post-synaptic to presynaptic actions, pentobarbitone was more potent than phenobarbitone in reducing synaptic efficacy (e.p.p. amplitude). 5. It is concluded that the presynaptic actions of pentobarbitone and phenobarbitone contribute significantly to barbiturate-induced changes in synaptic efficacy at low levels of transmitter release in the frog neuromuscular junction.


[Steroïedhormone in kleindierpraktyk (author's transl)].

The nature, origin, influence and interrelationships of the steroid hormones are reviewed. Clinical application and the treatment of feline and canine patients with these substances is discussed, with special reference to particular conditions which occur in male and female animals. The therapeutic use of corticosteroids in small animal practice are considered, and some general observations are made concerning precautions and side effects.


Antineoplastic and biochemical properties of arylsulfonylhydrazones of 2-formylpyridine N-oxide.

The structural parameters necessary for the antineoplastic potency of a new class of anticancer agents, arylsulfonylhydrazones of 2-formylpyridine N-oxide, were examined in mice bearing Sarcoma 180 ascites cells. The findings indicated that (a) replacement of the pyridine ring with benzene, quinoline, or isoquinoline resulted in loss of activity (b) movement of the formylhydrazone side chain from the 2 to the 3 or 4 positions of the pyridine N-oxide produced inactive agents (c) the pyridine N-oxide function was essential for anticancer activity, except for 4-substituted derivatives which were active without the N-oxide group, (d) replacement of the SO2 group by CO resulted in complete loss of activity, and (e) a carbon atom could be inserted between the SO2 and aryl ring with retention of anticancer potency. One of the most active members of this series, 1-oxidopyridine-2-carboxaldehyde p-toluenesulfonylhdrazone, exhibited antineoplastic activity against a broad spectrum of transplanted tumors including Sarcoma 180, Hepatoma 129, Ehrlich carcinoma, leukemia L1210, and a subline of Sarcoma 180 resistant to alpha-(N)-heterocyclic carboxaldehyde thiosemicarbazones. This agent caused inhibition of thymidine-3H and uridine-3H incorporation into DNA and RNA, respectively, of Sarcoma 180 ascites cells; protein biosynthesis was relatively insensitive to the action of this compound.


Synthesis of new cyclic nucleotides and their differential stimulatory effects on thyroid function in mice.

Various 8-substituted cAMP analogues were converted into the corresponding N6,O2'-dibutyryl, N6-monobutyryl, or O2'-monobutyryl derivatives and the parent compounds as well as the new derivatives were tested for TSH-like stimulation of the thyroid function in mice in vivo by means of the McKenzie bioassay. It was found that a pronounced stimulatory effect on the thyroid secretion can be produced by certain cyclic nucleotides. The most potent compounds, 8H2N-cAMP, 8MeS-cAMP, and 8N3-cAMP at 15-30 mg/kg iv, showed an activity approximately one order of magnitude higher than that of cAMP and comparable to the action of 0.6-1.0 mU of TSH per mouse iv. Radioimmunological determination of thyroxine levels in the serum confirmed these results. Serum T4 levels in mice injected, for instance, with 8MeS-cAMP (30 mg/kg) rose from 4.85 +/- 0.25 to 6.32 +/- 0.41 mug/100 ml in 1 h, the net increase in T4 being comparable to that produced by TSH (1 mU/mouse) under identical experimental conditions. Introduction of one or two butyryl groups (in the N6 and/or O2' position) significantly increased or decreased the biological activity, dependent on the parent compound, but no direct correlation between biological activity and degree of butyrylation was apparent. The effect of these compounds on the thyroid seems to be specific for cyclic nucleotides because 8MeS-5'AMP which resembles 8MeS-cAMP but lacks the cyclic phosphate structure is inactive in the McKenzie bioassay and in the T4 radioimmunoassay.


Synthesis and biological activities of 5-trifluoromethyl-5'-azido-2',5'-dideoxyuridine and 5-trifluoromethyl-5'-amino-2',5'-dideoxyuridine.

5-Trifluoromethyl-2'-deoxyuridine (1) was tosylated with p-toluenesulfonyl chloride in dry pyridine at 3 degrees to give 5-trifluoromethyl-5'-O-(p-tolylsulfonyl)-2'-deoxyuridine (2), which was converted to 5-trifluoromethyl-5'-azido-2',5'-dideoxyuridine (3) by reacting with lithium azide in N,N-dimethylformamide at 85-90 degrees for 2 h. Compound 3 was then hydrogenated in ethanol-water (1:1, v/v) at room temperature and 35 psi of hydrogen pressure, using 10% palladium on charcoal as cstalyst, to yield 5-trifluoromethyl-5'-amino-2',5'-dideoxyuridine (4). Compound 4 is about fourfold less potent than compound 1 as an antiviral agent but is about 40-fold less toxic to the host Vero cells. Thus the therapeutic index of compound 1 has been improved by a factor of 10 by replacement of the 5'-hydroxyl with an amino group. Compound 1, however, is more than 100-fold more inhibitory to Sarcoma 180 cells in culture relative to compound 4. Compound 3 is markedly less potent than compound 1 or 4 as either an antiviral or an antineoplastic compound.


Lanthanum and some other cation-induced changes in fluidity of synaptosomal membrane studied with nitroxide stearate spin labels.

Using nitroxide fatty acid spin labels, the effects of some cations such as La3+, Cd2+ and Hg2+ on synaptosomal membranes were studied by observing changes in their ESR spectra. The labels were incorporated almost instantaneously into synaptosomes isolated from rat brain cortex. ESR spectra of the spin-labeled synaptosomes were significantly braodened immediately upon adding La3+, Ce3+, Cd2+ or Hg2+ but hardly affected by Ca2+, Sr2+ and Ba2+. The magnitude of the change in the separation of the outer two peaks in ESR spectra (2T') depends on the number (n) of methylene units between the polar head group and the spin-label (nitroxide) group; that is, it increases with decreasing n. Among these ions, the effect of La3+ was the greatest and appeared to be in parallel with the amount of La3+ bound with the synaptosomes. On the other hand, K+, Rb+ or Li+ causes hardly any significant changes.


Ion transport by rabbit colon. I. Active and passive components.

Descending rabbit colon, stripped of muscularis externa, absorbs Na and Cl under short-circuit conditions and exhibits a residual ion flux, consistent with HCO3 secretion, whose magnitude is approximately equal to the rate of active Cl absorption. Net K transport was not observed under short-circuit conditions. The results of ion replacement studies and of treatment with ouabain or amiloride suggest that the short-circuit current ISC is determined solely by the rate of active Na transport and that the net movements of Cl and HCO3 are mediated by a Na-independent, electrically-neutral, anion exchange process. Cyclic AMP stimulates an electrogenic Cl secretion, abolishes HCO3 secretion but does not affect the rate of Na absorption under short-circuit conditions. Studies of the effect of transepithelial potential difference on the serosa-to-mucosa fluxes Jism of Na, K and Cl suggest that JNasm,JIsm and one-third of JCl-sm may be attributed to ionic diffusion. The permeabilities of the passive conductance pathway(s) are such that Pk:PNa:PCl= 1.0:0.07:0.11. Electrolyte transport by in vitro rabbit colon closely resembles that reported from in vivo studies of mammalian colon and thus may serve as a useful model for the further study of colonic ion transport mechanisms.


The molecular evolution of cytochrome c in eukaryotes.

Using many more cytochrome sequences than previously available, we have confirmed: 1, the eukaryotic cytochrome c diverged from a common ancestor; 2, the ancestral eukaryotic cytochrome c was not greatly different in character from those present today; 3, fixations are non-randomly distributed among the codons, there being evidence for at least four classes of variability; 4, there are similar classes of variability when the data are considered according to the nucleotide position within the codon; 5, the number of covarions (concomitantly variable codons) in mammalian cytochrome c genes is about 12 and the same value has been obtained for dicotyledenous plants as well; 6, all of the hyper- and most highly variable codons are for external residues, nearly 60 per cent of the invariable codons are for internal residues and nearly half of the codons for internal residues are invariable; 7, the first nucleotide position of a codon is more likely and the second position less likely to fix mutations than would be expected on the basis of the number of ways that alternative amino acids can be reached; 8, the character of nucleotide replacements is enormously non-random, with G-A interchanges representing 42% of those observed in the first nucleotide position, but the observation does not stem from a bias in the DNA strand receiving the mutation, nor from the presence of a compositional equilibrium, nor from a bias in the frequency with which different nucleotides mutate, but rather from a bias in the acceptability of an alternative nucleotide as circumscribed by the functional acceptability of the new amino acid encoded; and 9, the unit evolutionary period is approximately 150 million years/observable (amino acid changing) nucleotide replacement/cytochrome c covarion in two diverging lines. Wherever non-randomness has been observed, it has always been consistent with the consideration that an alternative amino acid at any location is more likely to be acceptable the more closely it resembles the present amino acid in its physico-chemical properties. Finally, in no case did the a priori assumption of a biologically realistic phylogeny lead to any observations or conclusions that were in any way significantly different from those obtained when the phylogeny was based solely upon the sequences, proving that the earlier results were not a consequence of some internal circularity.


Molecular evolution as a process of message refinement.

Amino acid sequences are often said to code for proteins. Taking that statement literally, we propose a methodology in which protein sequences appear as messages and as such are amenable to the techniques of signal analysis. Not only does this view of amino acid sequences as messages appear to be tenable, but the clarity of expression of these sequences seems to increase, i.e., the noisiness decreases, consonant with notions of ascendancy in the hierarchy of morphological taxonomy.


A vestibulothalamic pathway: electrophysiological demonstration in the cat by localized cooling.

Localized cooling was used in the search for vestibulothalamic pathways and a study was made of its effect on the activity of the thalamic neurons brought into action by stimulation of the vestibular nerve. Two cell populations were identified by their distinctive latencies in the ventral part of the posterior thalamus. Short latency responses were transmitted monosynaptically by means of a direct controlateral pathway whose course was identified. For long latency responses, the hypothesis of a polysynaptic path seems probable.


Temperature-sensitive mutants of vesicular stomatitis virus are conditionally defective particles that interfere with and are rescued by wild-type virus.

Temperature-sensitive (ts) mutants of vesicular stomatitis virus belonging to complementation groups I, II and IV inhibited the replication of wild-type vesicular stomatitis virus when mixed infections were carried out in BHK21 cells at 32, 37, and 39.5 C. The group IV mutant (ts G 41) was most effective in this regard; wild-type virus yields were inhibited almost 1,000-fold in mixed infections with this mutant at 32 C. In the case of group I and II mutants, inhibition of wild-type virus replication at 37 and 39.5 C was accompanied by an enhancement (up to 15,000-fold) of the yields of the coinfecting ts mutant. The yields of the group IV mutant (ts G 41) were not enhanced by mixed infections with wild-type virus at any temperature, although this mutant inhibited wild-type virus replication at all temperatures. The dominance of the replication of ts mutants at 37 C provides a rationale for the selection and maintenance of ts virus in persistently infected cells.


Synthesis of type C virus particles from murine-cultured cells induced by iododeoxyuridine. V. Effect of interferon and its interaction with dexamethasone.

Previous studies have shown that in certain cell systems dexamethasone may enhance the production of type C viruses. Conversely, interferon has been shown to inhibit their production. Both appear to exert their influence late in the viral replication cycle rather than on the synthesis of viral-specific RNA. In this report dexamethasone and interferon have been used to study some aspects of the mechanisms involved in the synthesis of type C viruses in murine K-BALB cells following induction of virus production by iododeoxyuridine. Interferon inhibited production of xenotropic type C virus induced by iododeoxyuridine from K-BALB cells both in the absence and presence of dexamethasone, but it did not affect production of N-tropic type C virus. Exposure of the cells to interferon for longer than 12 h was required for maximum effect. Two types of inhibitory effects were observed: one diminished by dexamethasone when the steroid was added 24 h after interferon removal, and the second resistant to dexamethasone. The concentration of intracellular group-specific antigen was diminshed after interferon and increased after dexamethasone exposure. When induced cells were treated with both interferon and dexamethasone, the intracellular group-specific protein concentration was slightly increased, but virus production was reduced 10-fold compared with induced cells treated with dexamethasone alone. We conclude that interferon and dexamethasone may affect both the synthesis of viral proteins and the assembly or release of virus particles and that dexamethasone can partially nullify the inhibitory activity of interferon. The results also support previous conclusions that the regulatory mechanisms for synthesis of viral proteins and for the release of viral particles may differ and that controls for xenotropic and ecotropic virus formation may not be identical.


Amphotropic host range of naturally occuring wild mouse leukemia viruses.

Seven murine leukemia virus field isolates (uncloned) from wild mice (Musmusculus) of four widely separated areas in southern California show an unusually wide in vitro host range. They replicate well in human, feline, canine, guinea pig, rabbit, rat, and mouse cells, whereas bovine, hamster, and avian cells are resistant. Since this host range includes that of both mouse tropic (ecotropic) and xenotropic murine leukemia viruses, they are designated as "amphotropic". No purely xenotropic virus component is detectable in these field isolates. They may represent the "wild" or ancestral viruses from which the ecotropic and xenotrophic murine leukemia virus strains of laboratory mice have been derived.


Structure of Herpesvirus saimiri genomes: arrangement of heavy and light sequences in the M genome.

Herpesvirus saimiri contains two species of DNA molecules. (i) The M genome is composed of 70% light (L) DNA (36% cytosine plus guanine; density in CsCl, 1.695 g/ml), which consists of unique sequences, and 30% heavy (H) DNA (71% cytosine plus guanine; density, 1.729 g/ml). (ii) The H genome contains heavy sequences exclusively. H sequences in M and H genomes cross-hybridize completely and are cleaved identically by restriction endonuclease R-Sma I into four classes of fragments with molecular weights of about 360,000, 300,000, 130,000 and 40,000, respectively. H sequences are chains of identical repeat units in tandem arrangement. The molecular weight of each repeat unit is about 830,000. L sequences have no cleavage site for endo R-Sma I H sequences are terminally arranged at both ends of the M genome, as seen by electron microscopy after partial denaturation. The length of the individual heavy ends varies between 21 mum and less than 1 mum, whereas the light region is uniform in size (35.3+/-0.35 mum). As a rule, molecules with a long heavy end at one side have a short heavy end at the other side, thus giving rise to a limited size heterogeneity. Orientation of M DNA molecules by the denaturation map of the light region shows that the longer heavy end may be located at the left or at the right side of the M genome.


Mechanisms of infection with Epstein-Barr virus. I. Viral DNA replication and formation of noninfectious virus particles in superinfected Raji cells.

Human lymphoblastoid Raji cells, which do not produce virus, supported replication of Epstein-Barr virus (EBV) upon superinfection. Early antigen, viral capsid antigen, and virions were produced in Raji cells superinfected with EBV. Viral DNA replicated under complete inhibition of host cell DNA synthesis to the extent that a few micrograms of EBV DNA were recovered from 107 superinfected Raji cells, corresponding to 5,000 viral genomes/cell. Homology of the synthesized viral DNA to parental EBV DNA was more than 90%. Virions produced by the Raji cells contained a 55S DNA but failed to induce early antigen, viral capsid antigen, and viral DNA synthesis after a second superinfection of Raji cells.


Cytomegalovirus proteins. I. Polypeptides of virions and dense bodies.

Cytomegalovirus virions and dense bodies were purified by sucrose velocity and equilibrium centrifugation from the medium of fibroblasts infected with the strain AD169. The final virus preparations were purified more than 228-fold with respect to cellular proteins as determined by double-isotopic labeling and at least 1,600-fold on the basis of changes in the ratio of total protein to virus particles. The protein content of purified particles approximated that found for purified preparations of other herpesviruses. Twenty polypeptides ranging from 22,000 to greater than 230,000 molecular weight were detected in purified virus preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Polypeptides of virions and dense bodies were allocated on the basis of analyses of preparations containing differing percentages of virions and dense bodies. Six polypeptides were represented predominantly or exclusively in virions, and four polypeptides were represented predominantly or exclusively in dense bodies, whereas the remainder appeared to be shared by both types of particles. Four polypeptides were glycosylated, and at least three of these appeared to be shared by both particles. Four polypeptides were glycosylated, and at least three of these appeared to be shared by both particle types. The protein composition of cytomegalovirus differs profoundly from that of herpes simplex virus.


Effect of trypsin on mouse mammary tumor virus.

Undisrupted mouse mammary tumor virus (MuMTV) derived from the milk of of RIII mice has been analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electron microscopy after treatment with insolubilized trypsin. No alterations were found in viral fine structure by either freeze-etch or negative-stain electron microscopy. No alterations were found in the ability of trypsinized virus to compete in a radioimmune assay for viral antigens. Infectivity experiments indicate no significant differences in the ability of treated virus to infect C57Bl mice. However, significant differences were observed in polypeptide composition. The intensely periodic acid-Schiff-positive band, gp140, was shown by galactose oxidase-borotritide labeling to be degraded into a fragment of 125,000 molecular weight. The major glycoprotein, gp55, was split into fragments of 36,000 and 23,000 molecular weight, both of which stained with periodic acid-Schiff stain. Gp68 was removed from the virus. Experiments with purified, iodinated gp55 showed that the trypsin-induced fragments of gp55 were immunologically active. We conclude that: (i) certain glycoproteins at the surface of MuMTV are accessible to an insoluble form of trypsin, (ii) the trypsin causes a nick in the polypeptide chain without affecting the configuration of the molecule; (iii) the nicked molecules remain bound to the virus; and (iv) the presence of these nicked molecules does not interfere with the biological or antigenic expression of virus function.


Comparative membrane microviscosity of fish and mammalian rhabdoviruses studied by fluorescence depolarization.

The microviscosity of the hydrophobic region of the membrane of infectious hematopoietic necrosis virus was determined using fluorescence depolarization analysis of the probe 1,6-diphenyl-1,3,5-hexatriene and was found to be much lower at 37 C than that of another rhabdovirus, vesicular stomatitis virus. However, the microviscosity of this fish virus at 18 C, the temperature at which it was grown, corresponded to the microviscosity of vesicular stomatitis virus at 37 C. Data obtained with the fish virus host cell (chinook salmon embryo cells) grown at 18 C suggest that its membranes have a lower microviscosity than either L-929 or BHK-21 cells (the vesicular stomatitis virus host cells) grown at 37 C.


Excision of viral DNA from host cell DNA after induction of simian virus 40-transformed hamster cells.

Simian virus 40-transformed hamster cells were induced to produce infectious virus by treatment with mitomycin C or gamma-irradiation. A portion of the simian virus-40 DNA, which is integrated into the host cell genome in uninduced cells, was recovered in a pool of relatively low-molecular-weight DNA early after induction treatment in the absence of DNA replication. The data indicte that excision of the viral genome occurs subsequent to the induction stimulus.


Role of temperature-sensitive mutants in persistent infections initiated with vesicular stomatitis virus.

Noncytocidal persistent infections at 37 C of mouse L cells (Lvsv) with infective B particles of vesicular stomatitis virus (VSV) could be established only in the presence of large numbers of defective interfering (DI) particles. Under these conditions, there was a rapid spontaneous selection of temperature-sensitive (ts) virus. At 10 days there was an increase to 17.8% in the frequency of ts clones in the virus population; by 17 days this frequency had reached 85.2%, and by 63 days 100% of the clones isolated were ts at 39.5 C, the nonpermissive temperature used. All 34 of the clones isolated from the 84-day fluid had an RNA-phenotype, and 8 clones that were tested all belonged to VSV complementation group I. When tested by an interference assay, Lvsv fluids did not contain significant numbers of DI particles (less than 1 DI/PFU). Furthermore, persistent infection of L cells at 37 C could be initiated under conditions in which few, if any, DI particles were present by using low input multiplicities (10(-4) and 10(-5) of a clonal isolate of an RNA-group I mutant obtained from Lvsv cells. On the basis of these and other results, a mechanism is proposed to explain the role of ts mutants in both the establishment and maintenance of the persistently infected state.


Neoplasia at the site of ureterosigmoidostomy.

An increased incidence of neoplasia at the site of ureterosigmoidostomy must be considered in patients being evaluated for or who have undergone this procedure. A case of mucinous adenocarcinoma 24 years following bilateral ureterosigmoidostomy is reported. This patient had bilateral hydroureteronephrosis, which led to left nephroureterectomy and right cutaneous ureterostomy. Mucinous adenocarcinoma was diagnosed only after the edematous, protruding and inflamed cutaneous ureterostomy stoma was biopsied. To our knowledge this is the first reported case of transfer of such a malignancy to the skin at the time of cutaneous ureterostomy. We recommend that ureterosigmoidostomy be performed only in patients with a limited life expectancy who agree to long-term followup. This followup should be frequent, complete and continue for the remainder of the patient's life. We consider the tendency for development of neoplasia at the ureterosigmoid anastomosis to be a relative contraindication to ureterosigmoidostomy. However, with proper patient selection and followup, ureterosigmoidostomy is still a remarkably satisfactory method of urinary diversion.


The absorption of antibiotics from the bladder.

The movement across the bladder epithelium of polymyxin B, bacitracin and neomycin is investigated in the human during postoperative irrigation. No appreciable amounts of these antibiotics enter the systemic circulation by this route.


Respiratory syncytial virus and heart disease. A report of two cases.

Two patients had cardiac disease and serological evidence for respiratory syncytial virus (RSV) infection. The first patient had myocarditis and complete atrioventricular heart block with repeated syncopal episodes two weeks following infection. The second patient had alcoholic cardiomyopathy and worsening congestive heart failure associated with RSV infection. The significance of RSV infection in these two patients may bear a significant relationship to sudden infant death syndrome, chronic cardiomyopathy, and alcohol-related heart disease. Cardiac disease secondary to RSV infection may be more prevalent than is presently recognized.


Recurrent conjugal neuralgia caused by Herpesvirus hominis type 2.

Leg neuralgia is usually caused by nerve root irritation, and is seldom considered of viral origin. Two married couples had recurrent leg pain in a dermatome distribution. In each episode, after one to three days of neuralgia, herpetic vesicles appear on or near the genitalia. Herpesvirus hominis (HVH) was isolated from vesicles or cervix in three patients and was serologically identified as herpesvirus honinis type 2. Prolonged follow-up has not shown progression of the syndrome or any permanent neurologic damage. Treatment with topical neutral red and photoinactivation has not only reduced local lesion healing time and frequency of attacks, but it has also given prompt relief of neuralgia.


True and false left anterior hemiblock: vectorcardiographic study.

For confirming the configuration of the QRS loop in left anterior hemiblock, 82 cases with the frontal QRS vector above minus 30 degrees were collected and classified by the configuration of the horizontal QRS loop. Thereafter, a comparison has been made between the configuration of the QRS loop in clinical cases and that in the authors' construction method, and the following findings for criteria of left anterior hemiblock are obtained. 1) The afferent limb of the frontal QRS loop is dislocated to the left and more superiorly. 2) The efferent and afferent limbs of the horizontal QRS loop are located left posteriorly. The configuration of the horizontal QRS loop is long and narrow and the direction of inscription is clockwise, a figure of 8 or counterclockwise. 3) Cases with the right posterosuperior dislocation of the afferent limb of the QRS loop is excluded from left anterior hemiblock.


Induction of antiviral activity in vivo and in vitro by human placenta ribonucleic acid treated with nitrous acid.

Induction of antiviral activity and interferon by human placenta ribonucleic acid deaminated with sodium nitrite (NO2-RNA) was studied in vitro and in vitro. (1) Viral multiplication in diploid cells from human kidney (HK cells) was depressed by pretreatment with NO2-RNA, but not by pre-treatment with the original placenta RNA. (2) NO2-RNA showed an interferon-inducing activity in rabbits and mice. (3) NO2-RNA sedimenting in 18 S and 28 S regions showed a higher antiviral activity than that sedimenting in 4 S region.


Further studies of the action of cyclic AMP on the electrical and mechanical activities of intestinal smooth muscle.

Effects of externally applied cyclic AMP and other adrenergic stimulants on the electrical and mechanical activities of the cat small intestine were observed by using pressure electrodes. The electrical and mechanical activities were suppressed by cyclic AMP and beta-stimulants. Those inhibitory actions of cyclic AMP and beta-stimulants were potentiated under the treatment with caffeine, theophylline and papaverine which inhibits the phosphodiesterase activity. On the other hand, the inhibitory action of cyclic AMP and beta-stimulants was decreased in imidazole, an agent that increases phosphodiesterase activity. Exogenous applied concanavalin A, an agent that inhibits the adenyl cyclase activity, showed no observable changes in both activities but the effects of beta-stimulants were decreased after treatment with concanavalin A. No obvious changes on both activities were obtained in cyclic GMP and dibutyryl cyclic GMP. These findings tentatively support the hypothesis that cyclic AMP is a second messenger in the inhibitory responses to beta-stimulants on the intestinal smooth muscle. However, it is also concluded that the inhibition of mechanical activity caused by cyclic AMP is partially due to suppression of the membrane activity.


[Experimental aortic stenosis, its subsequent correction and the activity of oxidative enzymes in the myocardium].

The activity of the respiratory enzymes of myocardial mitochondria--succinatedehydrogenase and cytochromixidase--was studied in experimentally induced aortic stenosis and after its elimination in 98 mongrel dogs. The observation period of stenosis was 1, 15, 30 and 60 days, and after its elimination--1, 7, 15 and 30 days. The activity of the enzymes in question was found to grow after the production of aortic stenosis. The highest level of their enzymatic activity was observed on the 15th day after the induction of stenosis. By the 30th and 60th day the enzymatic activity underwent some decrease, although it persisted on a level above the initial. The activity of succinatedehydrogenase fell sharper. After the elimination of the stenosis the activity of both enzymes decreased, and by the 7th day it was below the initial level. By the 15th day after the removal of the ligature from the aorta the activity of both enzymes corresponded to the initial values and did not change further till the end of the 1st month. The dynamics of the activity of succinatedehydrogenase and cytochromixidase after an experimentally induced aortic stenosis and its subsequent elimination seems to depend on the nature of the changes in the function of the heart muscle performed under such experimental pathology, and on the degree of coronary flow enhancement.


Morphology of the ascending thick limb of Henle.

The morphologic characteristics of the medullary and cortical segments of the ascending thick limb of Henle were examined in the rat utilizing light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The kidneys of six normal female Sprague-Dawley rats were preserved for morphological examination utilizing in vivo intravascular perfusion with 6.25% glutaraldehyde buffered in 0.1m sodium cacodylate. SEM revealed the presence of two distinctly different patterns of surface structure among the population of cells forming the epithelium of the ascending thick limb, a roughsurfaced cell with prominent microvilli (R cell) and a smoothsurfaced cell generally devoid of extensive microvilli except along the lateral cell margins (S cell). This variation in surface structure was confirmed with light microscopy and TEM. Throughout both the medullary and cortical segments of the ascending thick limb, the R cells possessed extensive lateral processes radiating form the main cell body to interdigitate with adjacent cells. Lateral processes of S cells were less common than those of the R cells in the inner stripe of the outer medulla, but increased in number and complexity in the outer stripe of the outer medulla and throughout the cortex. S cells outnumbered R cells in the inner stripe of the outer medulla. As the thick limb transversed the outer medulla and ascended toward the parent renal corpuscle, there was a marked increase in the relative number of R cells. In the cortical segment of the ascending thick limb, both the R and S cells tended to acquire a more extensive population of microvilli over their luminal surface making it increasingly difficult to establish clearcut distinctions between the two surface patterns. With the possible exception that vesicles and tubulovesicular profiles located in the apical region were more numerous in many of the S cells, additional morphological differences between the rough and smoothsurfaced cells were not evident. Whether the morphological results represent two distinct cell types or simply a variation in the structure of a single cell type, their presence must be considered in future structural-functional studies involving the ascending thick limb of Henle in the rat.


The glomerular mesangium: uptake and transport of intravenously injected colloidal carbon in rats.

Collodial carbon, 70 mg/100 g, was injected into rats which were sacificed for histologic study of the kidneys at intervals of five minutes to seven weeks. Transient thrombocytopenia and albuminuria were observed. Uptake of carbon by the mesangium of glomeruli was maximal at 32 hr and gradually decreased thereafter. Semiquantitative analysis of the distribution of carbon particles within glomeruli revealed a predominately peripheral localization during early time periods, and increased relative concentration of particles within more central zones and in the lacis area at the vascular pole of the glomerulus at two to seven weeks, indicating that one of the mechanisms for clearance of materials from the mesangium was movement of particles in the direction  of the lacis area. Sequential electron microscopic studies showed that carbon particles moved through fenestrae in the endothelium covering the mesangium into channels between mesangial cells. Observations at later intervals suggested that carbon eventually reached the vascular pole by being passed on from one mesangial cell to the next. Vasoactive amines or other substances derived from platelets may play an important role in initiating the process of mesangial uptake.


[Immunological cell surface markers in infectious mononucleosis (author's transl)].

Using a direct immunofluorescence technique and a spontaneous rosette formation with sheep red blood cells it could be demonstrated that the large mononuclear cells in infectious mononucleosis consisted mainly of T-lymphocytes. It is likely that infectious mononucleosis represents a primary B-lymphcoyte infection with the Epstein-Barr virus like in the Burkitt lymphoma. In contrast to this malignant lymphoma, interaction in infectious mononucleosis leads to a secondary T-lymphocyte proliferation.


Hypophosphatasia: a cytochemical study of phosphatase activities.

Skeletal abnormalities with defective formation of mature calcified bone are the most prominent clinical features of hypophosphatasia. Low concentrations of serum and tissue alkaline phosphatase and elevated plasma and urinary levels of phosphorylethanolamine (PEA) are also present. Although PEA is hydrolyzed by serum alkaline phosphatase, the relationship between PEA and the deficiency is unclear. PEA has not previously been tested as a cytochemical substrate for the in situ demonstration of human alkaline phosphatase activity. We have studied alkaline phosphatase activity in hypophosphatasia in tissue sections, utilizing PEA and adenosinetriphosphate (ATP) as well as the usual beta-glycerophosphate and naphthol phosphate substrates. Neutral and acid phosphatase activities were also examined. Our results demonstrate that PEA is a substrate for the localization of alkaline phosphatase in normal human tissue, but is not hydrolyzed in hypophosphatasia in the liver, brain or costochondral junction under alkaline conditions. In the kidney in hypophosphatasia only the straight segments of proximal tubules that rim the medullary rays are reactive with PEA. Similar results in hypophosphatasia were obtained at an alkaline pH with ATP, beta-glycerophosphate, and naphthol phosphate. However, the defect in hypophosphatasia is not a generalized deficiency of membrane-associated phosphatases because membranes that were deficient in alkaline phosphatase activity demonstrated normal reactivity with ATP at neutral pH. In addition, thiamine pyrophosphate was also split by Golgi membranes within the cytoplasm. Acid hydrolysis of beta-glycerophosphate by lysosomes was normal.


Isolated lamellar bodies from rat lung: correlated ultrastructural and biochemical studies.

Lamellar bodies isolated from rat lung homogenates were prepared for electron microscopy by two methods: OsO4 fixation followed by dehydration either with acetone or ethanol. Electron microscopy revealed that the acetone-dehydrated fraction contained many well preserved lamellar bodies with intact outer membrane, and the high retention of a material of low electron density between the fine and closely spaced concentric lamellae. This appearance was contrasted by the increased loss of this interlamellar material and coarse and irregularly spaced lamellae in the ethanol-dehydrated fraction. The supernatants from each respective fixation and dehydration were collected for lipid and protein analyses in an attempt to correlate any detected biochemical difference with a correspondingly modified ultrastructural appearance. Thin layer chromatography on the supernatant from the ethanol-dehydrated fraction revealed the extraction of 40 per cent lecithin and 4 per cent phosphatidylglycerol as compared to 1 per cent lecithin and an undeterminably small percentage of phosphatidylglycerol extracted by acetone dehydration. The effect of fixation and dehydration upon the extraction of chemical components of the lamellar bodies was compared to extraction by those of the following treatments: (1) freezing and thawing (a loss of 7 per cent lecithin, undetectably small losses of phosphatidylglycerol and protein); (2) incubation at 37 degrees C. with magnetic stirring (losses of 35 per cent lecithin, 5 per cent phosphatidylglycerol, and 4 percent protein, respectively); (3) sonication (loss of 57 per cent lecithin, 31 per cent phosphatidylglycerol, and 27 per cent protein, respectively). Further lipid analyses of the supernatants from dehydration and those obtained from the mechanical treatments revealed dipalmitoyl lecithin as the most readily extracted lipid. These data indicate that OsO4 fixation followed by acetone dehydration improves the preservation of the lamellar body ultrastructure by retaining an amorphous material between the lamellae, thus preserving the spatial relationship between the lamellae, and further that this improved morphologic preservation correlates well with retention of disaturated lecithin.


Biosynthesis of collagen and its alterations in pathological states.

The biosynthesis of collagen involves a number of unique post-translational modifications which are catalyzed by many specific enzymes. The main steps in collagen biosynthesis are transcription and translation, hydroxylations of prolyl and lysyl residues, glycosylations of hydroxylysyl residues, chain association and disulphide bonding, triple helix formation, secretion of procollagen into the extracellular matrix, conversion of procollagen into collagen, specific aggregation of collagen molecules and crosslink formation. Information about these modifications has rapidly increased during recent years, and initial information is available about the regulation and possibilities of specific pharmacological control of collagen biosynthesis at the level of these stages. Elucidation of the biochemical defect in an inborn error of collagen biosynthesis in man was reported for the first time in 1972 and subsequently several additional defects have been characterized. Alterations in collagen biosynthesis are also found during growth and ageing, as well as in many acquired pathological states: data about the nature of such changes in now rapidly accumulating.


Seeking a social disposition for the medical patient: CAAST, a simple and objective clinical index.

An index for the rapid and simple identification on admission of patients at high risk of becoming disposition problems was developed based on the patient's status of Continence, Ambulation, Age, Social Background, and Thought Processes (CAAST). One hundred seven consecutive admissions to City Hospital Center at Elmhurst were evaluated on admission according to the CAAST index and followed until discharge. The time that the patients remained in the hospital after their medical problems had been cared for was defined as social stay and was correlated with CAAST score. The high CAAST groups were found to have significantly increased mortality and longer average social stays with almost 40 per cent of their in-hospital time spent awaiting disposition. A high CAAST score should alert the physician to seek earlier help from social service in achieving a more rapid and more appropriate disposition for his or her patient.


Hemolytic anemias. Failure of the red cell membrane.

The normal erythrocyte membrane is composed of nearly equivalent amounts of lipid and protein. The lipid portion of the membrane has been well studied. Even though de novo synthesis of lipid does not occur in human red cells, many biochemical pathways exist which facilitate detoxification of lipid breakdown products and lipid renewal. Rare defects in these processes are associated with hemolytic disorders. Recent studies have revealed that the membrane proteins are diverse and suggest that protein dysfunction may also account for clinical disease. Protein and lipid are entwined in a physicochemical relationship which is probably best depicted by the classic lipid bilayer with interspersed proteins in both the inner and outer surfaces and also spanning the bilayer. Membrane failure results in hemolytic anemia. This failure can be intrinsic, caused by abnormal lipid or protein constituents; or extrinsic, with a normal membrane being unable to counteract physical, chemical or immunologic stress. Clinical examples of membrane failure and hemolytic anemia can be separated into three groups according to the predominant mechanism of the hemolysis: fragmentation, whole-cell lysis, and filtration and entrapment. Although these mechanisms can act separately or in concert, the final hemolytic destruction of the cell can usually be traced to a failure of membrane function.


[Single congenital granular cell myoblastoma (congenital epulis) of the gum].

A case of granular-cells (congenital epulis type) in the gum in a female newborn is reported. The differential characteristics between this tumor and the "so-called granular cell myoblastoma" are described.


Detection of ototoxicity from drugs applied topically to the middle ear space.

This paper summarizes data obtained from two separate studies done in our laboratory.  Both studies were done to investigate the possibility that drugs commonly applied to the middle ear space could be the cause of sensori-neural hearing loss.  The two drugs that were felt to be the most likely candidates for the studies were neomycin and polymyxin B.  In the neomycin study, the various drug concentrations were administered three times a day for four weeks.  In the polymyxin B study, the administration was three times a day for two weeks.  Cochlear function was evaluated electrophysiologically and by examination of surface preparations of the organ Corti.  The data show that both neomycin and polymyxin B can, in concentrations similar to those found in commercially available otic drops, induce cochlear damage when they are applied to the middle ear space of guinea pigs.  The degree of damage produced is related.  In the case of neomycin, it was shown that the effect worsens as the duration of the dosage administration is extended...


A critical analysis of current trends in the management of Bell's palsy.

The treatment of Bell's palsy has been a controversial subject for many years. During the past 10 years 152 papers pertaining to this affection of the facial nerve have apperaed in the American literature. Ninety-seven of these were general discussions of the etiology, pathology, prognosis and treatment of this condition: 20 were concerned with ascertaining the status of the facial nerve by electrical tests and four with the activity of the chorda tympani nerve in patients with Bell's palsy. The remaining 31 articles specifically discussed the treatment of Bell's palsy. As a result of this obvious interest in Bell's palsy, one would expect that the treatment of this affection of the facial nerve would be more or less uniform at this time. This is not the case, however, for the literature demonstrates it to be in a state of flux. Although steroid therapy has replaced other regimens of medical therapy to a large extent, surgical intervention still has its proponents. It is interesting to note that at the time of this review of the literature, no report of a controlled, double-blind study of the efficacy of steroid therapy for Bell's palsy has appeared in the American literature.


Effects of sex on formation and properties of plasma very low density lipoprotein in vivo.

The concentration and composition of the very low density lipoprotein (VLDL) lipids and the behavior of the VLDL in a density gradient in the zonal ultracentrifuge were examined in plasma obtained from normal fed male and female rats before and after intravenous injection of Triton WR-1339. Concentration of lipids in plasma VLDL of female rats was about half that of male animals. Following injection with Triton WR-1339, the concentration of VLDL lipids was higher in female rats (triacylglycerol) or similar (phospholipid, cholesterol, and cholesteryl esters) in both sexes. Female rats secreted much more VLDL traicylglycerol into the plasma compartment than did the male animals under the same experimental conditions. No differences were observed in lipid composition of the VLDL or in the position of the VLDL in the zonal rotor after ultracentrifugation in a density gradient of the lipoprotein from plasma of normal male and female rats before treatment with the detergent. However, after treatment with Triton, a higher proportion of the VLDL particles isolated from plasma of female rats displayed a more rapid rate-zonal flotation in the ultracentrifuge than did the VLDL produced by the male. The VLDL secreted by female rats contained fewer moles of phospholipid and free sterol per mol triacylglycerol than did the VLDL secreted by male animals under identical experimental conditions. The molar ratio of free cholesterol:cholesteryl ester in the VLDL secreted after treatment with Trition increased in both male and female rats. Simultaneously, the content of arachidonic acid in phospholipid of VLDL increased with a concomitant decrease in cholesteryl ester. These changes in fatty acid composition suggest that the inhibitory effect of Triton on lecithin-cholesterol acyl transferase activity affects the exchange of lipids between VLDL and high density lipoprotein. It can be concluded from the data reported here that sex influences the concentration of plasma lipids in vivo and the output and properties of the VLDL.


Delayed clearance of chylomicron remnants following vitamin-A-containing oral fat loads in broad-beta disease (type III hyperlipoproteinemia).

Chylomicron "remnants" are formed by the selective removal of triglyceride catalyzed by lipoprotein lipase. To investigate a possible defect in the clearance of these remnants in the pathophysiology of broad-beta disease (type III hyperlipoproteinemia), subjects with this disorder and comparison subjects with endogenous hypertriglyceridemia (and type IV lipoprotein patterns) ingested an oral fat load (corn oil: cocoa butter, 1:1, 50 g/sq M) containing retinyl ester, 100 mg, with or without 15 muCi 15-(14) C-retinol (43.7 mCi/mg). The content of triglyceride and vitamin A was sequentially determined in chylomicrons (Sf more than 400) and very low density lipoproteins (VLDS, Sf20-400) over the ensuing 24-72 hr. Vitamin A was chosen as a marker for exogenous sterol assimilation since, like cholesterol, it is absorbed in the small intestine and cosecreted in esterified form with triglyceride in the chylomicron core; however, unlike cholesterol, once having been removed by the liver, it cannot be recycled inot VLDL, but subsequently circulates only as a complex with the high density retinol binding protein. Thus measurements of the vitamin A/triglyceride ratio in Sf greater than 20 lipoproteins reflected the relative efficiency of vitamin A versus triglyceride removal within these lipoproteins. These studies confirmed the intital concentration of exogenous vitamin A in chylomicrons but invariably disclosed an increasing proportion of the remaining Sf greater than 20 vitamin A in VLDL 24 hr after its ingestion. The vitamin A/triglyceride ratio also invariably increased between 6 and 24 hr in the Sf20-30 subfraction, reflecting the formation of vitamin A-rich "remnants" as intermediate species in the catabolism of chylomicrons and VLDL. Among those with mild to moderate endogenous hypertriglyceridemia the Sf greater than 400 vitamin A/triglyceride ratio declined between 6 and 24 hr, reflecting the efficient passage of the vitamin A through this fraction and/or continued secretion of Sf greater than 400 particles rich in triglyceride. Among those with severe endogenous hypertriglyceridemia, both the peak and decline in the Sf greater than 400 vitamin A/triglyceride ratio were delayed. However, among those with broad-beta disease, an increasing vitamin A/triglyceride ratio between 6 and 24 hr was frequent within all VLDL subfractions and invariable among lipoproteins of Sf greater than 400 regardless of the degree of antecedent hypertriglyceridemia. Although additional experiments disclosed a similar delay in both vitamin A and triglyceride assimilation when basal triglyceride levels were high in these subjects, marked reduction of triglyceride levels did not correct the rise in the Sf greater than 400 vitamin A/triglyceride ratio between 6 and 24 hr. Experiments employing preparative electrophoresis confirmed the identity of VLDL containing a high vitamin A/triglyceride ratio with the beta-VLDL which accumulate in broad-beta disease...


The effect of bacterial infections on ketone concentrations in rat liver and blood and on free fatty acid concentrations in rat blood.

The concentrations of cytoplasmic lactate and pyruvate and the NAD+/NADH ratio and the concentrations of mitochondrial acetoacetate, beta-hydroxybutyrate, and the NAD+/NADH ratio were determined in normal, fed, and fasted rats, and in rats infected with Streptococcus pneumoniae, Francisella tularensis, and Salmonella typhimurium. The various infections were found to have little or no effect on the cytoplasmic parameters. In normal rats, fasting caused a marked increase in blood and hepatic ketone concentration and in serum free fatty acid content. Fasted infected rats, however, did not show the increase in ketone bodies or serum free fatty acids normally associated with fasting alone. The mitochondrial NAD+/NADH ratio increased as the infections progressed, reversing the normal trend. The introduction of an infection during the fasting state when ketone bodies and serum free fatty acids were elevated caused a marked depression in their concentration. These data have led to a postulation of decreased lipolysis in the infected host to account for the lowered hepatic and blood ketone bodies and the decreased level of serum free fatty acids.


The actions of parathyroid hormone on bone: relation to bone remodeling and turnover, calcium homeostasis, and metabolic bone diseases. II. PTH and bone cells: bone turnover and plasma calcium regulation.

Kinetic and morphologic studies in patients with parathyroid disease, and a wide variety of studies in experimental animals indicate that one major effect of PTH is to increase the proliferation of osteoprogenitor cells into osteoclasts and so to increase bone turnover. PTH stimulates bone cells by increasing cell membrane permeability to calcium and consequently increasing calcium influx and by activating membrane-bound adenyl-cyclase. It is likely that the former event precedes the latter and that calcium is the second messenger and cyclic AMP the third messenger. PTH increases the production by bone cells of lactate, citric and carbonic acids, lysosomal enzymes, collagenase, and hyaluronic acid, some or all of which are concerned in the mechanism of bone resorption. With the exception of lactate which probably comes mainly from osteocytes, the increase in metabolic activity is largely due to the increase in the number of osteoclasts. There is also ultrastructural, biochemical, and biophysical evidence that PTH stimulates existing osteoclasts, but this most likely represents the transformation of inactive cells into an active state, and is a transient and nonsustainable effect. As yet, there is no evidence that either increased osteoprogenitor cell proliferation or increased osteoclast activity is mediated by adenyl-cyclase activation. PTH also acts on the deep osteocyte to cause rapid mobilization of calcium from the zone of hypomineralized metabolically active perilacunar bone. This effect is mediated by adenyl-cyclase activation and is preceded by a slight fall in plasma calcium probably due to the movement of calcium into bone cells. The function of this rapid hypercalcemic response to PTH is correct errors in the prevailing steady-state level of plasma calcium...


[Comparative effect of various chloroactive compounds on the enzyme systems of Bacillus anthracoides spores].

The effect of various chloroactive compounds containing equal amounts of chlorine on respiration enzymes was studied in the spores of Bacillus anthracoides 96. These compounds inhibited the activity of malate dehydrogenase, fumarase, and aconitase but stimulated the activity of glucose-6-phosphate dehydrogenase, succinate dehydrogenase, and ketoglutarate dehydrogenase. Therefore, the action of these compounds is rather specific, and the inhibition of the activity of some enzymes is one of the factors causing the sporocidal effect.


Prostaglandins, possible mediators of the effects of oestrogens on luteinizing hormone output.

A possible mechanism for the positive and negative feed-back effects of oestrogen on luteinizing hormone (LH) output is suggested. It is proposed that oestrogens may influence prostaglandin synthesis in the hypothalamus in relation to LH releasing hormone (LH.RH) synthesis and release. Changes in oestrogen level or in the oestrogen to progesterone ratio may alter the ratios of prostaglandin concentrations in the hypothalamus, and so modulate LH.RH output through effects on sympathetic neurotransmission, protein synthesis or LH.RH release.


Fine structure of the URA2 locus in Saccharomyces cerevisiae. II. Meiotic and mitotic mapping studies.

The URA2 locus codes for a multifunctional enzyme complex carrying aspartate transcarbamylase (ATCase) and carbamyly phosphate synthetase (CPSase) activities. Three different types of ura2 mutants were tested in meiotic and mitotic recombination experiments: ura2A mutants devoid of ATCase activity, ura2C mutants devoid of CPSase activity and ura2B mutants devoid of both activities. All the ura2A mutations were found to be clustered at one end of the URA2 locus, called zone A, while the ura2C mutations were localized in a region at the other end, called zone C. All but two ura2B mutations (most of them suppressible) were distributed throughout zone C; the two ura2B exceptions which are small deletions, mapped in zone A. On the meiotic as well as on the mitotic map an intermediary or dead-space zone is located between zones A and C. No mutation has yet been found to map in this zone. The relative lengths of the three zones A, intermediary and C are 1 :2-3 :3-4, respectively. These data are consistent with the hypothesis that the URA2 locus consisting of at least two cistrons: C (CPSase) and A (ATCase), is transcribed into a single polycistronic message in the direction C to A. However, alternative hypotheses in reference to Peterson and MacLaughlin's observations (1973) are discussed.


Division delay and DNA degradation after mutagen treatment of the yeast, Saccharomyces cerevisiae.

The treatment of the yeast mutant TMP1-1, which is capable of incorporating low levels of 3H-thymidine-5' - monophosphate with UV light and ethyl methane sulphonate resulted in division delay when cultures were reinnoculated into fresh medium. The initiation of cell division was accompanied by the degradation of up to 20% of the nuclear DNA fraction. The period of DNA degradation correlates closely with the time at which yeast cultures undergo mitotic recombination and appears to represent the degradation of DNA during a post-replication repair process.


[Electron microscopic study of natural SiO2 particles and SiO2 particles isolated from rat lung].

Natural SiO2 particles of 0--4, 0--5 and 5--10 micron of size were investigated by the aid of transmission and scanning electron microscope. Silicosis in rats was induced with SiO2 particles of 0--5 micron of size. After 18 month SiO2 was isolated from the silicotic lung and investigated by the aid of transmission and scanning electron microscopy and with electronmicroscopic diffraction technique. Natural and isolated from silcotic lung SiO granules were divided into different groups according to their planimetrycally measured area, and excentricity calculated from their diameter. It was established, that division of silica particles isolated from lungs became different as compared to the natural silica-dust. Among the silicadust isolated from silicotic lungs of rats proportion of finer granules is much higher than in natural silica-dust-fraction. Granules isolated from lung have rounded edges and part of them shows a decrease of electrondensity. Majority of particules of 0,01 micron of size appears to be isolated in the material got from the silicotic lung.


[Biochemical form of a paraneoplastic Cushing's syndrome (author's transl)].

Paraneoplastic hypercorticism appears either as a fullfledged Cushing's syndrome with adiposity of the trunk, moon face and striae or as a biochemical form with hypokalemic alkalosis, adynamia and muscular atrophy. A form of the disease with the biochemical type in bronichial carcinoma is reported, which emphasizes also the significance of paraneoplastic syndromes for the early diagnosis of neoplasia.


[The character of the distribution of chloroplast DNA from higher plants in a cesium chloride density gradient].

The nature of distribution of the chloroplast DNA from three species of higher plants (Sp. oleracea, N. tabacum, P. sativum) in the CsCl density gradient has been investigated DNA preparations isolated from the fractions of chloroplasts completely deprived of the admixtures of nuclei and mitochondria are characterized by symmetric distribution in the density gradient. Fragmentation of chloroplast DNA of higher plants is not accompanied by the appearance of the discrete satellite components. It has been shown that the satellite DNA component found in the fraction of the unpurified chloroplasts are entirely mitochondrial DNA.


Studies on DNA repair in early spermatid stages of male mice after in vivo treatment with methyl-, ethyl-, propyl-, and isopropyl methanesulfonate.

In vivo DNA repair occurring in early spermatid stages of the mouse has been studied with four mutagens that are chemical homologs: MMS, EMS, PMS and IMS. Using the well-studied sequence of events that occurs during spermatogenesis and spermiogenesis in the mouse, aatids was measured by the unscheduled incorporation of [3H]dT into these germ cells which were recovered from the caudal epididymides 16 days after chemical treatment. Purification of the caudal sperm DNA at this time verified that the [3H]dT was incorporated into the DNA. For each chemical mutagen a study was made on the level of DNA repair occurring in early spermatids as a function of the administered, in vivo dose. Within experimental errors, all four chemicals produced a linear increase in DNA repair in early spermatids with increasing dose. Only the highest dose of MMS (100 mg/kg) produced a greater repair response than expected for a linear curve. At equimolar doses the most effective chemical in inducing DNA repair was MMS, followed by EMS, IMS and PMS. When testicular injections of [3H]dT were given at the same time as the intraperitoneal injections of the mutagens, the amount of unscheduled incorporation of [3H]dT into the DNA of early spermatids was maximized. Since [3H]dT has been shown to be available for incorporation into germ-cell DNA for only approximately 1 h after injection, all four mutagens must reach the DNA of early spermatids and begin producing "repairable" lesions within 1 h after treatment. The amount of DNA repair occurring at later times after chemical treatment of early spermatids was studied by testicular injections of [3H]dT 1/2, 1, 2 and 3 days after chemical treatment. Repair was still occurring in the early spermatids at 3 days post-treatment; this repair is most likely a manifestation of the finite rate of the repair process rather than resulting from newly alkylated DNA. For MMS and EMS there was a rapid decrease in the level of DNA repair in the first 1/2 day following treatment. This was followed by a much slower, exponential decrease in the level of repair out to 3 days post-treatment. The curves suggest that the amount of repair is proportional to the number of repairable lesions still present in the DNA. For PMS and IMS the level of repair decreases rapidly in the first 1/2 day after treatment and thereafter remains relatively constant through 3 days post-treatment. With all four mutagens, DNA repair in early spermatids was detectable at doses 5 to 10 times lower than those required to observe other genetic end points such as dominant lethals, translocations and specific-locus mutations in any germ-cell stage. The sensitivity of detection of in vivo DNA repair in the germ cells of male mice makes such a system a useful adjunct to other genetic tests for studying chemical mutagenesis in mammals.