Merkel cell tumor with liver metastases: presentation as fulminant hepatic failure

This report demonstrates that hepatic metastases can present with fulminant hepatic failure and that liver enzyme abnormalities may not become prominent until there has been massive replacement of the liver. The CT scan of liver may not demonstrate diffuse liver metastases as seen in this patient. Merkel cell tumor or trabecular neuroendocrine skin tumor is a previously unreported cause for the development of the syndrome of hepatic failure due to liver metastases.

cAMP induces a transient elevation of cGMP levels during early culmination of Dictyostelium minutum

Oscillatory cAMP signals very likely organize the cell movement which leads to fruiting body construction in Dictyostelium minutum [Schaap, P., Konijn, T.M. and Van Haastert, P.J.M.: Proc. Natl. Acad. Sci. USA 81, 2122-2126 (1984)]. Stimulation with cAMP induces a transient elevation of cGMP in cells at the early culmination stage, which peaks at 12-18 s. A half maximal cGMP response is induced by 10(-7) M cAMP and saturation of the response is reached at 10(-5) M cAMP. No cGMP accumulation was induced by stimulation of vegetative or aggregative cells of D. minutum by cAMP. Since the transient increase of cGMP is most likely involved in the transduction of chemotactic signals, our results indicate that cAMP signals organize fruiting body formation by inducing chemotaxis inside the aggregate.

EEG effects of subcutaneous and intracerebroventricular injections of arginine vasopressin in the rat

Several studies have suggested that arginine vasopressin (AVP) may act centrally as a neurohormone or neuromodulator to produce electrophysiological and behavioral effects. However, there are few reports of EEG effects of AVP in unanesthetized, behaving animals. In the present study the EEG effects of "behaviorally relevant" subcutaneous (SC) doses of AVP (6 micrograms/kg) known to raise blood pressure were compared to "behaviorally relevant" intracerebroventricular (ICV) doses (0.1-1.0 ng) and multiple "toxic" ICV doses (1.0 microgram) of AVP. Central injections of toxic doses of AVP produced behavioral arrest, bodily barrel rolling, and EEG slowing, but did not induce electrographic signs of seizure activity. Comparison of the spectral characteristics of the EEG revealed some similarities in the distribution of power between SC and the 1.0 ng ICV dose; whereas ICV doses of 0.1 and 0.5 ng produced power distributions that were different from those seen following saline or SC doses of AVP. The similarities in EEG activity between SC injections and the 1.0 ng ICV dose suggest a common brain state may be induced by the two routes of administration in those dose ranges.

The possible involvement of oscillatory cAMP signaling in multicellular morphogenesis of the cellular slime molds

The involvement of pulsatile chemoattractant emission and signal relay in aggregation and multicellular morphogenesis of a variety of cellular slime mold species was investigated. The species differ from each other in the developmental stage when pulsatile signaling first becomes evident. In D. discoideum, D. mucoroides, and D. purpureum pulsatile signal emission starts in the preaggregative field. In D. vinaceo-fuscum, D. mexicanum, P. violaceum, and P. pallidum the aggregation centers shifts from continuous to pulsatile secretion of chemoattractant during the aggregation process. In D. minutum pulsatile signaling starts after the completion of aggregation and slightly before the onset of culmination. Tip formation is a consequence of continued attraction of amoebae inside the aggregate to the center of signal emission. The occurrence of pulsatile signaling at an early stage of development is correlated with the capacity of the tip (signaling center) to organize a relatively large number of cells into a single fruiting body. Several lines of evidence suggest that cAMP is probably involved in the coordination of morphogenetic movement in the multicellular stage of all investigated species.

Synaptic connections from large muscle afferents to the motoneurons of various leg muscles in man

Cross-correlations between stimuli delivered to peripheral nerves and the discharges of single, voluntarily activated, motor units can provide information about facilitatory and inhibitory projections to single spinal motoneurons in man. The projection frequency, under the given circumstances, of a facilitatory or inhibitory pathway can be obtained from the proportion of the sampled motor units of a given muscle showing the facilitatory or inhibitory effect. Deductions about the shape and relative amplitude of the underlying post-synaptic potentials can be made from the profile of the changes in firing probability. This technique has been used to explore the projections of low threshold muscle afferents to motoneurons of various leg muscles in man. Homonymous facilitation was demonstrated to all the sampled motor units of soleus (SOL), medial gastrocnemius (MG), tibialis anterior (TA) and vastus medialis (VM) and is presumed to represent the effects of the composite muscle spindle group Ia EPSP. Heteronymous facilitation was demonstrated between certain synergists. The projection frequency was less and the magnitude of the change in firing probability was smaller than for homonymous facilitation. SOL motoneurons, however, were not facilitated from low threshold afferents in the medial gastrocnemius nerve. Reciprocal inhibition was demonstrated between certain antagonists. The majority of the sampled motor units of SOL, however, were facilitated from low threshold afferents in the common peroneal nerve. The threshold for this facilitation was higher than for the homonymous facilitation elicited from this nerve and thus a different class of afferents and/or intercalated interneurons may be involved. There are projections across the knee joint in man. Motor units in vastus medialis (VM) were facilitated from low threshold afferents in the common peroneal nerve. It is likely that these reflex connections, which differ from those in other species, reflect the functional relationships between various lower limb muscles in man.

Microtubule polarity and the direction of pigment transport reverse simultaneously in surgically severed melanophore arms

The transport of pigment through the long cytoplasmic extensions (arms) of teleost melanophores is a microtubule-dependent event. We have severed the arms from melanophores to test whether microtubules isolated from the centrosome maintain their original polarity and disposition. In addition, we have tested whether arms containing microtubules of mixed polarities alter the direction of pigment transport. We find that microtubules within severed arms eventually change their polarity and reorganize from the arm center as if to form a new minicell. Concomitant with this change is a reversal in the direction of pigment transport.

EEG spectra following phenytoin infusion in seizure patients

Diphenylhydantoin (DPH) kinetics were studied in five male patients with poorly controlled seizures. EEG recordings were taken on four of the patients immediately prior to and 30 minutes following a 60 minute i.v. infusion of phenytoin sodium. Mean phenytoin levels following post-infusion EEG recordings were 17.1 mg/L. Spectral analysis revealed that phenytoin produced a decrease in the variance of EEG spectral power as a function of time in frequencies between 8-18 Hz. This decrease in the variance of the time series of EEG spectra suggests increased EEG stability and may represent an electrographic marker of the anticonvulsant action of phenytoin.

GTP cyclohydrolase I deficiency, a new enzyme defect causing hyperphenylalaninemia with neopterin, biopterin, dopamine, and serotonin deficiencies and muscular hypotonia

A 4-year-old patient is described with hyperphenylalaninemia, severe retardation in development, severe muscular hypotonia of the trunk and hypertonia of the extremities, convulsions, and frequent episodes of hyperthermia without infections. Urinary excretion of neopterin, biopterin, pterin, isoxanthopterin, dopamine, and serotonin was very low, although the relative proportions of pterins were normal. In lumbar cerebrospinal fluid, homovanillic acid, 5-hydroxyindoleacetic acid, neopterin and biopterin were low. Oral administration of L-erythro tetrahydrobiopterin normalized the elevated serum phenylalanine within 4 h, serum tyrosine was increased briefly and serum alanine and glutamic acid for a longer time. Urinary dopamine and serotonin excretion were also increased. Administration of an equivalent dose of D-erythro tetrahydroneopterin was ineffective and demonstrated that this compound is not a cofactor in vivo and cannot be transformed into an active cofactor. GTP cyclohydrolase I activity was not detectable in liver biopsies from the patient. The presence of an endogenous inhibitor in the patient's liver was excluded. This is the first case of a new variant of hyperphenylalaninemia in which the formation of dihydroneopterin triphosphate and its pterin metabolites in liver is markedly diminished. Normal activities of xanthine oxidase and sulfite oxidase were apparent since uric acid levels were normal and no increase in hypoxanthine, xanthine, and S-sulfocysteine concentrations could be observed in urine. It is concluded that the molybdenum cofactor of these enzymes may not be derived from dihydroneopterin triphosphate in man. Also, since no gross abnormalities in the patient's immune system could be found, it seems unlikely that dihydroneopterin triphosphate metabolites, such as neopterin, participate actively in immunological processes, as postulated by others. See Note added in proof.

Intrageneric and intergeneric transfer of Branhamella catarrhalis beta-lactamase production

Intrageneric and intergeneric conjugational transfer of beta-lactamase production to a Branhamella catarrhalis recipient is described. The branhamella donor strains were fresh isolates subcultured onto penicillin-containing media directly from the primary plates. A beta-lactamase positive Moraxella nonliquefaciens served as donor in the intergeneric matings. The substrate profiles of the branhamella and moraxella enzymes were indistinguishable as determined by biological assays. Excessive endonuclease activity did not permit a conclusive characterization of isolated extrachromosomal DNA from the branhamella donors.

Corticotropin releasing factor produces increases in brain excitability and convulsive seizures in rats

Corticotropin releasing factor (CRF) is a 41-residue peptide, capable of stimulating the secretion of corticotropin (ACTH)-like and beta-endorphin-like immunoreactivity from the adenohypophysis. Low doses of CRF (0.0015-0.15 nM) given intracerebroventricularly (i.c.v.) produced changes in electrographic activity suggestive of increased arousal. Higher doses of CRF (1.5-3.75 nM) induced, over a period of 3-7 h, electrographic and behavioral signs of seizure activity indistinguishable from those which occur following electrical 'kindling' of the amygdala.

Multiple acyl-Co A dehydrogenation deficiency (MADD) in a boy with nonketotic hypoglycemia, hepatomegaly, muscle hypotonia and cardiomyopathy. Detection of N-isovalerylglutamic acid and its monoamide

A boy, aged 7 months, of consanguineous parents presented with an acute onset of vomiting, fever, nonketotic hypoglycemia and acidosis and died from cardiac arrest after ventricular fibrillation. He had hepatomegaly and echocardiographically a non-obstructive cardiomyopathy. Autopsy was not allowed. After birth the child had suffered from a severe respiratory distress syndrome, transient metabolic acidosis and had a sweaty feet odour. Later on, development was retarded with a severe muscular hypotonia. Post mortem, numerous unusual organic acids were found in high concentrations in urine, e.g. dicarbonic acids, 2-hydroxyisobutyric, isovaleric, 3-hydroxyisovaleric acid, N-acyl glycines, isovalerylglutamic acid and sarcosine. This pattern indicated deficiencies of several acyl-Co A dehydrogenases in the metabolism of leucine, isoleucine, valine, lysine, short-chain fatty acids and sarcosine. This could be confirmed using cultured skin fibroblasts which were shown to degrade the corresponding labeled substrates insufficiently to 14CO2. It is assumed that the functional multiple acyl-Co A dehydrogenation deficiency is caused by a deficiency of a common link in the electron transfer system of these dehydrogenases which is inherited autosomal recessively in this family. Among the 12 patients reported, 7 died within the first 5 days of age.

The results of radiation therapy in advanced carcinoma of the lung in the Beijing region of China

From 1958 to 1973, 682 patients with lung cancer were treated by radiation therapy in the Cancer Institute, Chinese Academy of Medical Sciences, Beijing, China. The clinical presentation, sex, age, histology and stage and palliative effects of radiation therapy were reported. The 1-, 3- and 5-year survival rates were 40.62, 8.94 and 3.81%, respectively. The prognostic factors such as staging, histology, combination with chemotherapy and response of tumours are discussed. The causes of failure are also analysed. It is suggested that improving the local control rate of squamous cell carcinoma would increase the survival rate.

Atypical phenylketonuria with defective biopterin metabolism. Monotherapy with tetrahydrobiopterin or sepiapterin, screening and study of biosynthesis in man

Administration of a single dose of tetrahydrobiopterin dihydrochloride, 10--20 mg/kg orally, to a patient with dihydrobiopterin deficiency led to disappearance of clinical symptoms for 4 days, normalization of urinary phenylalanine and serotonin and decrease of elevated neopterin for 2--3 days. A dose-dependent stimulation of serotonin production was observed. A similar effect was noted with even lower doses of L-sepiapterin. The patient is now under monotherapy with tetrahydrobiopterin . 2 HCl, 2.5 mg/kg daily. Other patients with this disease may not respond as well. Results of screening for tetrahydrobiopterin deficiency in 228 cases with hyperphenylalaninemia, including 140 newborns, are reported. There is evidence that biopterin biosynthesis in human kidney and liver proceeds via a dioxo compound and L-sepiapterin.