Cerebral glucose metabolic rates after 30 and 45 minute acquisitions: a comparative study

This study was undertaken to determine if measurements of absolute regional cerebral metabolic rate for glucose (rCMRglc) and variance of rCMRglc are independent of time between 30 and 45 min following injection of the radiotracer. Sixteen subjects received two sets of 18FDG PET scans commencing 30 and 45 min following intravenous injection of 18FDG. No statistically significant differences were detected in either absolute rCMRglc or rCMRglc variance between the two sets of scans. These data demonstrate that for most FDG PET studies, scanning can commence 30 min after injection of the radiotracer without compromising the metabolic data.

Fatty acids, calcium soaps of fatty acids, and cottonseeds fed to high yielding cows

We examined the effects of dietary fat as cottonseed, fatty acids, or calcium soaps of fatty acids in the rations of high yielding lactating cows receiving low forage. Experiments were with isoenergetic, isonitrogenous diets containing equal amounts of forage. Inclusion of up to 510 g/d of fatty acids in the ration enhanced FCM yield. With cottonseed, increased FCM was mainly due to increased fat yield. Dietary fatty acids tended to increase milk in mid and late lactation and to decrease fat percentage. Calcium soaps of fatty acids enhanced FCM, particularly in early lactation. Feeding cottonseed and fatty acids together did not enhance yield. Effects described may be attributed in part to changes in ruminal fermentation in which cottonseed increased acetate concentrations and fatty acids decreased the ratio of acetate and butyrate to propionate and in part to enhanced efficiency of milk yield when fat was included in the ration.

Molecular analysis of the gene for the human vitamin-D-binding protein (group-specific component): allelic differences of the common genetic GC types

DNA sequence analysis of the polymerase chain reaction products, including the coding region for amino acids 416 and 420, of the vitamin-D-binding protein (DBP, group-specific component, GC) shows allele-specific differences. The GC2 and GC1F phenotypes have an aspartic acid residue at amino acid position 416, whereas the GC1S phenotype has a glutamic acid at this position. In the GC2 phenotype, amino acid 420 is a lysine residue, and in the both common GC1 phenotypes, it is a threonine residue. The nucleotide exchanges involve a HaeIII (position 416) and a StyI (position 420) restriction site: the HaeIII restriction site is specific for the GC*1S allele and the StyI restriction site is specific for the GC*2 allele. We have tested 140 individual genomic DNA samples for the HaeIII site and 148 samples for the StyI site by restriction fragment length polymorphism (RFLP) analysis with a DBP-specific direct genomic DNA probe, and have compared these findings with the GC phenotype classification, by isoelectric focusing (IEF) of the corresponding plasma. The results of the HaeIII RFLP analysis and the IEF typing were in complete agreement. By using our DNA probe, we could disclose, in addition to the StyI site at amino acid position 420, two further StyI site downstream: one was specific for the GC*1S allele and another for the GC*1F allele. In 147 samples, there was agreement between the IEF GC typing and the analysis of the StyI restriction sites. In a single case, the observed result of the StyI-digest differed from the result expected after IEF classification: homozygous GC 1F-1F by IEF and heterozygous by StyI RFLP analysis. We discuss this finding as a recombination event or a possible silent allele in IEF typing. The GC polymorphism revealed by Southern blot analysis of StyI-digests provides an informative DNA marker system for chromosome 4q11-q13.

[Sonography in therapy-oriented diagnosis and after-care of primary bone and soft tissue tumors]

Based on the results of 150 patients with primary tumors or the suspicion of malignant lesions of the locomotor system the perspectives and limits of the sonographic diagnosis under the therapeutic aspects of interdisciplinary oncologic cooperation is demonstrated. As the ideal adjunct to conventional roentgenograms, ultrasound is the first-line imaging procedure in the fields of primary diagnosis, follow-up, post-therapeutic care as well as tumor exclusion for methodic, patient-related and economic/logistic reasons. Its consequent application will markedly reduce the number of more invasive and expensive methods.

A comparison of FDG PET and IQNB SPECT in normal subjects and in patients with dementia

Prior studies of patients with dementia have found similar qualitative patterns of cerebral glucose utilization with [18F]2-fluoro-2-deoxyglucose (FDG) PET and of putative muscarinic receptor activity with [123I]3-quinuclidinyl-4-iodobenzilate (IQNB). This raised doubts about whether receptor binding determines IQNB distribution and whether clinical information in IQNB scans is unique. To compare the methods directly, 4 normal volunteers and 7 patients with dementia underwent FDG PET and high-resolution IQNB SPECT scans. In normal subjects, relative regional activity from the paired scans was only weakly correlated (r = 0.29). Some regions (e.g., thalamus, frontal cortex) showed a clear disassociation of activity. In demented patients, IQNB scans tended to show larger defects than FDG scans, although one focal defect appeared only with PET. Results suggest that IQNB SPECT data are not primarily related to general physiological activity or regional cerebral blood flow and are not explained by attenuation or volume-averaging artifacts. Further studies should investigate whether IQNB scanning is a more sensitive in vivo measure of the extent of Alzheimer's disease than is FDG PET.

In vivo dissociation kinetics of [3H]quinuclidinyl benzilate: relationship to muscarinic receptor concentration and in vitro kinetics

The in vivo washout kinetics of [3H]quinuclidinyl benzilate ([3H]QNB) varies significantly in various structures in the rat brain. The slowest washout rates are from the hippocampus, corpus striatum, and cortex, intermediate rates are exhibited from the thalamus and colliculi, while the fastest washout rate is from the cerebellum. We have also demonstrated a difference in the in vitro dissociation rates (k-1) of [3H]QNB from various structures. The k-1 for the hippocampus, corpus striatum and cortex, is two-fold slower than that observed in the thalamus, colliculi, and cerebellum. The differences in the in vitro dissociation kinetics are not, however, sufficient to explain the differences in the in vivo washout kinetics. We have developed a theoretical formulation which describes conditions under which the washout kinetics are a function of the concentration of receptor in a structure. Furthermore, we present a graphical method in which a plot of the reciprocal of the observed washout rate constant, 1/k(obs), vs receptor concentration is linear. Analysis of the washout kinetics of [3H]QNB from various structures of the CNS of rat were well described by this theory when the differences in in vitro k-1 are included.

Compression therapy of limb edema using hydrostatic pressure of mercury

A new apparatus for the treatment of edema of the extremities is described. The extremity is placed in a cylindrical vertical tank and isolated by a circumferential synthetic rubber membrane. The equipment is programmed to create a mold of the extremity using a slurry of plastic granules from a reservoir. Mercury is then pumped between the mold and the extremity, thereby exerting a pressure gradient on the extremity equal to the hydrostatic pressure of the mercury column. A computerized program forms the mold and runs several compression cycles for each treatment session. Twelve patients were treated (8 upper extremities, 4 lower extremities) on a weekly or semiweekly basis. Progress was followed with computed axial tomography scans, as well as measurements and photographs. Ten patients experienced significant immediate decrease in edema with each treatment. Wrapping or elastic support was required to prevent the return of edema between treatments. No pain, skin injury, or other complication of treatment was noted. The apparatus can safely provide short-term, immediate, significant improvement of extremity edema. Further studies will be necessary to determine long-term benefit.

Binding of ATP to uncoupling protein of brown fat mitochondria as studied by means of spin-labeled ATP derivatives

ATP derivatives spin-labeled (SL) at C8, N6, C2' or C3' were employed in binding studies with the uncoupling protein of brown fat mitochondria. Substitution of the ribose strongly impaired binding, whereas labeling of the adenine moiety allowed for tight and functional complex formation. Detailed binding studies with C8-SL-ATP confirmed the known pH and Mg2+ dependence with a stoichiometry of one C8-SL-ATP bound per 66 kDa dimer. Corresponding studies of the uncoupling protein after modification with N-ethylmaleimide or diazobenzene-4-sulfonic acid revealed distinct differences in their effects on nucleotide binding and gating.

Interaction of the vitamin D-binding protein (group-specific component) and its ligand 25-hydroxy-vitamin D3: binding differences of the various genetic types disclosed by isoelectric focusing

The three common variants of the vitamin D binding protein, also known as group specific component (Gc), namely types 1S, 1F and 2, as well as some rare variants were studied by thin-layer polyacrylamide gel isoelectric focusing in a pH 4.5-5.4 carrier ampholyte generated pH gradient, additionally containing N-(2-acetamido)-2-aminoethanesulfonic acid (ACES). Prior to isoelectric focusing, whole serum or purified preparations of the vitamin D binding protein were incubated with 25-hydroxycholecalciferol at various ligand/protein ratios. Binding differences were found for the anodal and cathodal isoforms of Gc 1 variants and also for various allelic types. Isoforms with higher isoelectric points generally had a lower affinity for the ligand than the variants with lower isoelectric points.

Identification and partial purification of embryonic mouse genital protein(s) stimulating phospholipase-A2 and inducing masculinization in vitro

The present study was designed to test whether phospholipase-A2 stimulatory protein (PLSP) has any role during androgen-induced masculine differentiation. Thus, an investigation was made to identify such a protein in the fetal genital tract and to test whether this protein can produce masculinization in vitro. Fetal tracts (15/batch) containing genital ducts and urogenital sinus from male, female, and testosterone-exposed (40 mg/kg.day, from days 13-17 of gestation) female embryonic mice on day 18 of gestation were fractionated using Bio-Rad P-100 gel filtration, DEAE-cellulose, and carboxymethyl-Sephadex chromatography. Phospholipase-A2 (PLA2) stimulatory activity was identified at every step of purification. The final preparation stimulated both bee venom and mouse genital PLA2; however, it had no effect on PLC. The preparation lost its PLA2 stimulatory activity after pronase treatment. The partially purified PLSP fraction produced two bands (63K and 55K), as determined by sodium dodecyl sulfate-gel electrophoresis, and its PLA2 stimulatory activity appeared at the region of 55K on a P-100 gel filtration column. PLSP was also identified in female and testosterone-exposed female genital tracts. However, the specific activity of the female PLSP was much lower than that of the male or testosterone-exposed females. Sodium dodecyl sulfate-gel analysis of 2-3 micrograms partially purified PLSP revealed the presence of a faint 55K band in the females compared to the presence of a darker 55K band in the male and testosterone-exposed female. The intensity of the 63K band was similar in both sexes. PLSP from the male and testosterone-exposed females maintained and stimulated the Wolffian duct, whereas PLSP from the female tract had no masculinizing effect. Thus, the masculinizing activity of the PLSP preparation appears to correlate with its PLA2 stimulatory activity and 55K band intensity, suggesting the role of PLA2 stimulatory protein in masculine differentiation.

A monoclonal antibody against human vitamin-D-binding protein for the analysis of genetic variation in the group-specific component system (Gc)

We have developed a murine hybridoma cell line that is stable in secreting a monoclonal antibody (hDBP-1) directed against the group-specific component (Gc) molecule. The hDBP-1 is monospecific for Gc and does not crossreact with human albumin, which has 23% of its amino acid residues identical with vitamin-D-binding protein (DBP). The subclass of the antibody is IgG1 for the heavy chain, the light chain being of the kappa type. Isoelectric focusing discloses four major bands for the hDBP-1 with isoelectric points between pH 6.5 and 7.8. Binding to the antigen at different pH values was determined: there is high affinity in the physiological range and no binding at pH 3.5 and lower. In the presence of high salt concentrations, binding was reduced to about 50% at 1.5 M NaCl. The hDBP-1 recognizes the common human Gc types and the Gc of all apes and old world monkeys. No reaction was observed with the Gc of other mammals such as horses, cattle, rats, rabbits, sheep, goats and pigs. By testing hDBP-1 against 77 of the more than 120 known rare human Gc variants, it could be shown that this monoclonal antibody cannot recognize seven of these rare variants and can only poorly recognize nine. The binding site of hDBP-1 to Gc is not related to the binding site of Gc with G-actin: it recognizes Gc, the binary complex between Gc and G-actin, as well as the ternary complex between Gc, G-actin and DNase I. Competition assays with vitamin D3 and Gc in enzyme-linked immunosorbent assay indicate that the epitope of hDBP-1 on the Gc molecule may be related to the vitamin-D3-binding site.

Oxygen inhibition of globin gene transcription and bacterial haemoglobin synthesis in Vitreoscilla

A soluble dimeric haemoprotein, structurally and functionally similar to plant and animal haemoglobins, is found in the Gram-negative aerobic bacterium Vitreoscilla sp., strain C1. Vitreoscilla haemoglobin (VtHb) increases in concentration when the cells are exposed to hypoxic conditions. The globin part of VtHb is encoded by a single gene (vgb). An RNA transcript, approximately 500 bases long, specific for vgb was detected after Northern hybridization. The relative amount of this mRNA increased in cells grown at low levels of oxygen. Two enzymes important for haemoglobin function are delta-aminolaevulinic acid synthase (ALAS), which is necessary for haem biosynthesis, and NADH-methaemoglobin reductase, which is necessary to keep VtHb in the physiologically functional ferrous state. An increase in ALAS specific activity under hypoxic conditions preceded the increased haem production. Cellular reductase content also increased when the VtHb increased in cells grown under hypoxic conditions. The ratio of cellular reductase activity to VtHb content remained relatively constant in cells grown under a variety of conditions. The data suggest that in Vitreoscilla the transcription of the globin gene and the biosynthesis of two enzymes important for VtHb function are regulated by oxygen.

Selective D-1 dopamine receptor agonist effects in hyperkinetic extrapyramidal disorders

The motor and cognitive effects of a selective D-1 dopamine receptor agonist, SKF 39393, were assessed in patients with Huntington's disease, Gilles de la Tourette's syndrome, tardive dyskinesia, and torsion dystonia, using a double-blind placebo-controlled design. Over daily doses ranging from 3.2 to 32 mg/kg and treatment intervals extending from one to seven weeks, no consistent changes could be discerned. The contribution of D-1 receptor mediated mechanisms to the pathophysiology of hyperkinetic extrapyramidal disorders remains uncertain.

Dopamine D-1 receptor agonist stimulation of prolactin secretion in man

SKF 38393, a selective D-1 dopamine receptor agonist, elevated plasma prolactin levels in eight patients with various neurological disorders. Growth hormone concentrations were unaffected by SKF 38393 administration. The results suggest that D-1 receptors may be involved in the regulation of prolactin secretion.

[Clinical introduction to aneurysmatic bone cysts]

The aneurysmal bone cyst is according to the description of Jaffe and Lichtenstein (1942) a histomorphological entity. It is a benign centric or eccentrically localized tumor like lesion with preference to the metaphysis. 75% of all aneurysmal bone cysts occur within the first two decades of life. On x-ray the diagnosis is not always clear. In differential diagnosis juvenile bone cyst, giant cell tumor, chondroblastoma, chondromyxoid fibroma, non ossifying fibroma, fibrous dysplasia and telangiectasic osteogenic sarcoma have to be considered. Final diagnosis requires histological evaluation. Curettage or resection with bone grafting is the predominant therapeutic procedure. Radiotherapy might cause malignant degradation and should only be used in elected cases. For propaedeutic evaluations of aneurysmal bone cysts 851 cases in world literature are reported.

cDNA cloning and complete sequence of porcine choline acetyltransferase: in vitro translation of the corresponding RNA yields an active protein

A cDNA clone encoding the complete sequence of porcine choline acetyltransferase (ChoAcTase; acetyl-CoA: choline O-acetyltransferase, EC 2.3.1.6.) has been identified. A cDNA library, constructed from poly(A)+ RNA of ventral spinal cord, was screened with a mixture of eight oligonucleotides corresponding to the N-terminal sequence of pig brain ChoAcTase. Among five positive clones, one, pChAT-1, was identified as a ChoAcTase cDNA clone based on the following criteria. (i) This clone has an open reading frame coding for a protein of the size expected for ChoAcTase (640 amino acids). (ii) The amino acid composition deduced from the nucleotide sequence of this open reading frame matches that of purified porcine ChoAcTase. (iii) When subcloned in the T7 expression system, the corresponding RNA directs the synthesis in the rabbit reticulocyte lysate of a protein that is specifically immunoprecipitated by antibodies raised against ChoAcTase. (iv) Finally and most important, this corresponding RNA, when translated in the reticulocyte lysate, as well as in the Xenopus oocyte system, directs the synthesis of a protein displaying ChoAcTase activity. This activity is inhibited by the specific ChoAcTase inhibitor 4-(1-naphthylvinyl)pyridine. Comparison of porcine ChoAcTase sequence with that of Drosophila reveals 32% identity between these proteins, when the sequences are suitably aligned. pChAT-1 probe hybridizes with a porcine mRNA species that is at least 7000 nucleotides long, whereas the equivalent rat mRNA species is 3700 nucleotides long.

Unsuitability of the assay for cell-mediated lympholysis in inbred mice for H-Y antigen determination of human cells

This study examined the H-Y-specific in vitro restimulation of splenocytes from in vivo intraperitoneally (i.p.) primed C57B1/6 (B6) female mice. In vivo priming was carried out with human male or female fibroblasts or peripheral blood lymphocytes, respectively. It was attempted to measure the in vitro H-Y-specific activity by cell-mediated lympholysis and by cell proliferation. 3[H]Thymidine incorporation was determined in mixed lymphocyte cultures (MLCs) of xenogeneic primed female splenocytes (responder cells) and of syngeneic lethally irradiated male splenocytes (stimulator cells). The xenogeneic H-Y presentation by in vivo sensitization did not induce in the in vitro restimulation system an H-Y-specific cell proliferation or in the effector phase the generation of H-Y-specific killer cells. The assay for cell-mediated lympholysis and lymphocyte proliferation after xenogeneic priming and syngeneic in vitro restimulation is, thus, not suitable for H-Y testing of human cells.

[Nuclear receptors in estrogen receptor negative tumors with progesterone receptors]

The nuclear estrogen receptors ERn were determined in 12 carcinomas whose cytoplasm contained progesterone receptors PRc but no estrogen receptors ERc. ERn were found in 9 of the tumors. Their concentration correlated to those of PRc and reached a mean of only 20% of the ERn concentrations found in ERc+/PRc + carcinomas. These results suggest that in carcinomas of the ERc-/PRc+-type, originally present cytoplasmic estrogen receptors induce the synthesis of progesterone receptors in a concentration corresponding to that of the nuclear receptors, following translocation by endogenous estradiol in the nucleus.

Selective D-1 dopamine receptor agonist treatment of Parkinson's disease

Preclinical evidence suggests that the D-1 dopamine receptor contributes to the generation of behaviors used as models for human extrapyramidal disorders. To evaluate the potential of D-1 receptor stimulation in neurologic disease, SKF 38393, a selective D-1 dopamine receptor agonist, was administered to seven patients with idiopathic Parkinson's disease in a double-blind, placebo controlled study. SKF 38393 was found to be rapidly absorbed when administered orally, and to occur in micromolar concentrations in spinal fluid. No change in scores of parkinsonian severity were noted when SKF 38393 was administered alone, or when the drug was combined with intravenous levodopa. The results support the view that the pathophysiology of Parkinson's disease may relate exclusively to the D-2 subclass of dopamine receptors.

N-terminal sequence of pig brain choline acetyltransferase purified by a rapid procedure

A procedure is reported that allows the purification and amino terminal sequencing of pig brain choline acetyltransferase. The enzyme (present in extremely low amounts in this tissue) is eluted together with its antibody from an affinity column by a mild pH shift and the resulting enzyme-antibody complex separated by gel electrophoresis. The band corresponding to the enzyme is electroeluted from the gel using volatile solutions allowing the direct determination of the amino acid composition and partial sequence. The first 11 residues are: Pro-Ile-Leu-Glu-Lys-Thr-Pro-Pro-Lys-Met-Ala.

[Real-time sonography. An important imaging procedure in the diagnosis and treatment planning of bone metastases]

The value of sonography for diagnosis and therapy planning of bone metastases is shown in 110 affected skeletal regions (60 patients with malignant diseases). Whereas sonography is inferior to conventional x-ray in respect of defects of the spongiosa, it is equal with regard to defects of the cortical layer but superior in respect of changes of the periosteum and the surrounding soft tissue. Moreover, there is an excellent correlation (97%) between pain and the reaction of periosteum and soft-tissue layer. Because of the three dimensional representation of the tumourous processes sonography has proved valuable in radiotherapy planning (field size, radiation method, risk organs etc.).

[Carbon band implants in animal experiments. Light and transmission electron microscopy studies of biocompatibility]

Part of the patella ligament was resected in rabbits and replaced by carbon fibre implants. After 1, 2, 3, 6 weeks, 3 and 12 months carbon implants with surrounding tissues as well as iliac lymph nodes were removed and examined by light- and transmission electron microscopy. Of special interest were the questions whether the carbon fibre implant, will be removed by phagocytosis and substituted by a new ligament or a adequate repair tissue? Our light- and transmission electron microscopic studies give no indication of successful removal of carbon fibres by phagocytosis. The carbon fibre implant was surrounded by dense connective tissue like a scar. In deep layers of the carbon implant was no vital dense or regular connective tissue, even not after 3 and 12 months. There is no replacement of the carbon fibre implant by a new ligament or tendon but a persistent foreign body reaction. With regard to these results it is very doubtful if good late results with ligament and tendon replacement by carbon fibre implants can be expected in patients.

[Spontaneous occlusion of a thoracic duct fistula following leftsided shoulder girdle amputation]

Reference is made to the anatomy and variant courses of the thoracic duct, as well as to possibilities of surgical and conservative therapy. A chylous fistula developed in a 53-year old man after his left shoulder girdle had been amputated because of a recurrent low grade chondrosarcoma. Nineteen liters of chyle were excreted over a 5-week period. It was possible to achieve a spontaneous occlusion of the fistula by means of repeated punctures, compression bandages, and a low-fat diet.

[Bone tumors and tumor-like changes in the neonatal period and in infancy]

Bone tumours and tumour-like lesions occurring in newborns and infants are described presenting 5 own cases and a literature review. Age specific features in diagnosis, therapy and prognosis are discussed. Due to the rarity of these diseases a centralized registry at a national level is recommended.

[Extremity preserving interventions in malignant bone tumors]

Amputation or exarticulation are the easiest and safest ways to effect a radical cure of a malignant musculo-skeletal tumor. With progress in adjuvant chemotherapy and development of endoprosthetic devices tumor resections became more important for limb salvage procedures. Competitive surgical techniques for curative treatment always require radical tumor elimination.

N-13 L-glutamate uptake in malignancy: its relationship to blood flow

Studies on glutamate uptake, with special reference to perfusion, were carried out in 35 rats, each bearing one of five different tumor transplants; also in 15 rats after bone fracture, and in three rabbits. Single-pass extraction of N-13 glutamate was 85-93% in the VX2 tumor of the rabbit and in muscle. Bone fracture in rats caused a threefold increase of tracer uptake 2 days after the event. In tumor transplants, the tumor-to-muscle uptake ratio reached a maximum immediately following injection of the tracer. Comparing N-13 glutamate uptake with the retention of 1-121 microspheres, identical tumor-to-muscle ratios were found for three out of five tumor lines. Comparing the uptake with that of C-11 butanol (ten rats), a close correlation was observed throughout the range of tumor lines. The results suggested that glutamate uptake by malignant tumors is related to blood flow. In nine patients with malignant or benign lesions tumor-to-muscle uptake of N-13 glutamate and TI-201 showed a linear correlation close to identity.

Orthopedic surgery for management of tumor pain

Benign primary bone tumors, tumor-like lesions, and semimalignant bone tumors with pain are in most cases an indication for surgery with marginal or wide excision. In malignant primary bone tumors, the relief of pain does not have primary importance in the therapeutic concept. With en bloc resection or amputation, the cause of cancer pain is eliminated. Limb salvage procedures can be performed by endoprosthetic replacement, and phantom or stump pain will not occur. Skeletal metastases can be very painful owing to bone destruction, expansive growth, and consecutive pathologic fractures. Orthopedic surgery can relieve pain and improve the quality of life. Endoprosthetic replacement and combined osteosynthesis with PMMA and metallic implants are used to achieve early rehabilitation.

[Contribution of computer tomography to the evaluation of space-occupying processes and abnormalities of the skeletal system]

The contribution made by computed tomography to the diagnostics of the skeletal system was studied in the basis of 53 examinations in patients with space-occupying growths and malformations. With reference to clinical final diagnoses the CT findings were graded into I. Correct diagnosis or diagnosis by exclusion, II. Contribution to determining the growth of the process, III. No additional information obtained via CT. The distribution of these grades was as follows: Grade I = 34%, II = 49%, III = 17%. Indications for CT of the skeletal system were based on the following problems: primary malignant bone tumours; bone metastases in the region on the vertebral column; benign and potentially malignant bone tumours and abscesses in the region of the skeleton itself and of the skull; suspected diastematomyelia; assessment of the vertebral canal in case of suspected inflammatory or tumorous changes of the adjacent areas as well as exclusion of osseous changes in the region of the vertebral canal with peripheral neurological symptoms. CT serves to determine the exact dimension of the growth; to prove infiltration of organs and structures; for the planning of operations; for controlling the course; and for diagnosing relapses.

Long-term suppression of central serotonergic activity by corticosteroids: a possible model of steroid-responsive myoclonic disorders

Chronic administration of cortisol succinate (12.5 mg per kilogram per day) to guinea pigs suppressed jumping behavior induced by 1-5 hydroxytryptophan and abolished diurnal threshold variations of this behavior. Chronic corticosteroid administration did not alter threshold or diurnal variations of apomorphine-induced stereotypy. These observations suggest that the efficacy of corticosteroids in some human myoclonic movement disorders may be related to central serotonergic inhibition.

A family with whistling-face-syndrome

A family with 7 persons affected with whistling-face-syndrome in 3 successive generations is described. The clinical variability of the syndrome within one family is demonstrated by means of examining particular characteristics of four daughters in the family. Six affected persons are female; the only male carrier died in early infancy because of the severity of symptoms. The known autosomal dominant inheritance combined with clinical variability and bias towards female manifestation is present in this family.

Effect of transient lambda prophage induction on ultraviolet light resistance and recombination in Escherichia coli

Transient induction of lambda prophage increases the ultraviolet light resistance of most exponentially growing Escherichia coli lysogens. Resistance is increased in wild-type, recB, recB recC, recB recC recF, and recB recC recL hosts. No enhancement in recA lysogens was found, nor was there enhancement in stationary cultures. Enhancement was dependent upon the lambdared recombination system. Transient induction also increases the genetic recombination rate in recB lysogens as measured in Hfr X F- matings.

Hyphal walls of isolated lichen fungi: autoradiographic localization of precursor incorporation and binding of fluorescein-conjugated lectins

The hyphal walls of three mycobionts, isolated from the lichens Xanthoria parietina, Tornabenia intricata and Sarcogyne sp. were investigated by two techniques: microautoradiography of fungal colonies exposed to radioactive carbohydrate precursors: and binding, in vivo, of fluorescein conjugated lectins to hyphal walls of such colonies. N-[3H] acetylglucosamine was readily incorporated into tips, young hyphal walls and septa of the three mycobionts and the free-living fungus Trichoderma viride, but not into Phytophthora citrophthora, indicating that chitin is a major component of the mycobionts' hyphal walls. All three mycobionts, but neither of the free-living fungi, incorporated [3H] mannose and [3H] mannitol into their hyphal walls. Fluorescein-conjugated wheat germ agglutinin was bound to the hyphal walls of the three mycobionts and T. viride, but not to the walls of P. citrophthora; the binding pattern was similar to the grain pattern obtained in autoradiographs after short N-[3H]acetylglucosamine labelling. As wheat germ agglutinin binds specifically to chitin oligomers, the lectin binding tests further confirmed that chitin is a mycobiont hyphal wall component. Binding characteristics of several fluorescein-conjugated lectins to the three mycobionts indicated that this technique can yield useful information concerning the chemical composition of hyphal wall surfaces.

Modification of the regulatory properties of pyruvate kinase of Neurospora by growth at elevated temperatures

Pyruvate kinase (EC 2.7.1.40) was isolated from Neurospora crassa mycelium grown at 28 degrees C (PK-28) and at 42 degrees C (PK-42). The regulatory properties, particularly the response towards the allosteric effector fructose 1,6-diphosphate (FDP), was different in the two enzymes. PK-28 showed an activation by FDP but PK-42, under comparable conditions, appeared to be activated by low concentrations of FDP and inhibited by higher ones. For PK-28, complex formation with FDP results in a lowering of the isoelectric point from 6.40 to 5.50, representing the pI of the unliganded enzyme and that of the complex, respectively. In contrast to this, PK-42 exhibits a weak binding to FDP as suggested by a lack of decrease in the isoelectric point on treatment with comparable concentrations of FDP. Studies with quenching of aromatic residue fluorescence of PK-28 and PK-42, following binding of FDP, indicate that although this ligand binds to both types of enzymes the affinity for the two is vastly different. Dissociation constants of 9.3 muM and 0.1 mM were calculated for the binding of FDP to PK-28 and PK-42, respectively. It is concluded that growth at elevated temperatures induced a conformational change in the pyruvate kinase leading to partial desensitization of the allosteric site. The nature of the factor(s) responsible for this change is not understood at present.

The Escherichia coli UV endonuclease (correndonuclease II)

An endonuclease from Escherichia coli which acts specificially upon UV-irradiated DNA (correndonuclease II) and is absent from the uvrA and uvrB mutants has been isolated and partially chacterized. The enzyme is present in normal amounts in the urvC mutant. It elutes from phosphocellulose at about 0.25 M potassium phosphate (pH 7.5) and passes through dialysis tubing. The enzyme binds tightly to UV-irradiated DNA but does not bind to unirradiated DNA. The enzyme incises irradiated DNA to the 5' side of a pyrimidine dimer and leaves a 5'-phosphoryl terminus which can be resealed with polynucleotide ligase. The Km of the enzyme is about 1.5 X 10(-8) M dimers. Endonucleolytic activity of the enzyme is inhibited by caffeine with a KI of about 10mM.

An endonuclease from Escherichia coli that acts preferentially on UV-irradiated DNA and is absent from the uvrA and uvrB mutants

At least two endonucleolytic activities that preferentially incise ultraviolet (UV)-irradiated DNA exist in extracts of E. coli. These two activities can be separated by phosphocellulose chromatographic fractionation. The subject of this paper is one of these activities, which elutes from phosphocellulose with 0.25 M potassium phosphate, pH 7.5. This endonucleolytic activity specific for UV-irradiated DNA is absent from partially purified extracts of uvrA and uvrB mutants, which are defective in excision of pyrimidine dimers, but is present in normal amounts in the uvrC excision-defective mutant. The enzyme binds very tightly and specifically to UV-irradiated DNA. Binding can be prevented by prior treatment of the irradiated DNA with photoreactivating enzyme. This binding activity is absent in uvrA and uvrB mutants, but present in uvrC and uvrD mutants.