Effects of retinoids on tooth morphogenesis and cytodifferentiations, in vitro.

The first embryonic lower mouse molar was used as a model system to investigate the effects of two retinoids, retinoic acid (RA) and a synthetic analogue, Ch55, on morphogenesis and cytodifferentiations in vitro. Exogenous retinoids were indispensable for morphogenesis of bud, cap and bell-stage molars in serum-free, chemically-defined, culture media. Transferrin and RA or transferrin and Ch55 acted synergistically in promoting morphogenesis from bud and cap-stage explants. Transferrin, per se, had no morphogenetic effect. Epithelial histogenesis, odontoblast functional differentiation and ameloblast polarization always occurred in RA-depleted explants. Comparison of the distributions of bromodeoxyuridine (BrdU) incorporation between explants cultured in the absence or presence of RA revealed that RA could modify the patterns of cell proliferation in the inner dental epithelium and dental mesenchyme. Inner dental epithelium cell proliferation is regulated by the dental mesenchyme through basement membrane-mediated interactions, and tooth morphogenesis is controlled by the dental mesenchyme. Laminin is a target molecule of retinoid action. Using a monospecific antibody, we immunolocalized laminin and/or structurally-related molecules sharing the laminin B chain in the embryonic dental mesenchyme and in the dental basement membrane and showed that RA could promote the synthesis or secretion of these molecules. Based on previous in situ hybridization data, it was speculated that CRABPs might regulate the effects of RA on embryonic dental cell proliferation. The fact that Ch55, a retinoid which does not bind to CRABPs, is 100 times more potent than RA in promoting tooth morphogenesis in vitro seems to rule out this hypothesis. On the other hand, the stage-specific inhibition of tooth morphogenesis by excess RA is consistent with the hypothesis that CRABPs might protect embryonic tissues against potentially teratogenic concentrations of free retinoids.


Altering the position of the first horizontal cleavage furrow of the amphibian (Xenopus) egg reduces embryonic survival.

The animal/vegetal cleavage ratio (AVCR), defined as the ratio of the height of the animal blastomere to the height of the Xenopus embryo at the 8 cell stage, can be shifted by placing embryos in novel gravitational fields: clinostating (microgravity simulation) increases AVCR, and centrifugation (hypergravity simulation) reduces AVCR. This report contributes to an understanding of the subcellular mechanism responsible for the furrow relocation and assesses its significance. Embryo inversion and D2O immersion were found to increase AVCR, and cold shock was found to reduce AVCR. Based on the additive or antagonistic effects of combined treatments, it is postulated that the primary cause of AVCR changes is an alteration in the distribution of yolk platelets and the rearrangement of microtubule arrays. Embryos with a decreased AVCR exhibited reduced survival in early developmental stages, indicating serious difficulties in cleavage, blastulation and/or gastrulation. Cold-shocked embryos with a reduced AVCR could be rescued by D2O pretreatment or clinostating, an observation which supports the notion that changes accompanying AVCR modifications represent the primary cause of the reduction in percent survival.


Differentiation of endocrine myocardiocytes in the developing heart of the toad (Bufo arenarum Hensel).

The differentiation of endocrine myocardiocytes was investigated in the heart of developing toad Bufo arenarum Hensel, combining ultrastructural and immunocytochemical procedures. The distribution of immuno-reactive atrial natriuretic peptide (ANP) in the whole heart was appraised by light microscopy, applying biotin-streptavidin and immunofluorescence techniques. With the latter procedures ANP was first recognized at embryonic stage 22, in both atrium and ventricle. In the ensuing stages the ANP-reactivity became stronger in the atrium, while it became dimmer in the ventricle. At the end of the larval prometamorphic stage, atrial myocardiocytes acquired almost all the features of adult myoendocrine cells. At electron microscope level, small inclusions, about 110-120 nm in diameter, resembling secretory granules were found in myoendocrine cells beginning at embryonic stage 22. However, no immunogold labeling of ANP occurred until stage 25. The number of secretory granules diminished in the ventricles and increased in the atrium of the larval heart and at the end of the prometamorphic stage the atrial myoendocrine cells presented the ultrastructural characteristics of active secretory cells. The synthesis of ANP in larvae is enhanced at a critical period of development when the developing toad switches from an aquatic environment to terrestrial life. The cardiac hormones seem to play a key role in the regulation of the osmolarity of body fluids at this developmental stage.


Changes in embryonic 8-cell nuclei transferred by means of cell fusion to mouse eggs.

Metaphase II and activated mouse oocytes were fused with 8-cell blastomeres, and morphological changes in the transferred nuclei were followed using light and electron microscopy. In metaphase II oocytes, blastomere nuclei underwent premature chromosome condensation (PCC) typical for S-phase nuclei: chromatin pulverization. Then an abortive spindle was formed without evident microtubule organizing centers. Blastomere chromosomes condensed to a lesser degree than meiotic chromosomes and lacked mature functional, trilaminar kinetochores. After parthenogenetic activation of these oocytes, blastomere chromosomes followed, in synchrony with oocyte chromatin, a similar route of changes (anaphase, telophase) and then reformed interphase nuclei of the pronuclear type. Remodeling of 8-cell nucleus thus occurred, but the integrity of the chromatin set was frequently disturbed by formation of micronuclei. If blastomere fusion with oocytes was done close to activation (either before or after parthenogenetic stimulation), the chances of remodeling of the nuclei decreased, because PCC was not regularly induced in all oocytes. In hybrids produced 60 min or later after oocyte activation, blastomere nuclei were maintained in interphase without any structural modifications. Multiple experiments in the mouse have shown that the nuclei from 8-cell stage transferred to enucleated oocytes and egg cells are not capable of substituting for pronuclear functions. Possible reasons for impaired functional reprogramming of 8-cell nucleus in the mouse are discussed in light of our present findings on the morphology of nuclei transferred before and after oocyte activation.


Patterns of dystrophin expression in developing, adult and regenerating tail skeletal muscle of Amphibian urodeles.

The patterns of expression of dystrophin were investigated by indirect immunofluorescence and by immunoblotting in developing, adult and regenerating tail skeletal muscle of newts Pleurodeles waltl and Notophthalmus viridescens. In this study, a monoclonal antibody H-5A3 directed against the C-terminal region (residues 3357-3660) and a polyclonal antibody raised to the central domain (residues 1173-1738) of the chicken skeletal muscle dystrophin were used. Western blot analysis showed that these antibodies recognized a 400 kDa band of dystrophin (and may be of dystrophin-related protein) in the adult muscle tissues and in newt tail regenerates. During skeletal muscle differentiation or epimorphic regeneration (blastema), anti-dystrophin immunoreactivity gradually accumulated over the periphery of the myofibers. Dystrophin and laminin were first and concomitantly observed at the ends of the newly formed myotubes where they were anchored on connective tissue septa or bone processes by dystrophin-rich myotendinous structures. It is noteworthy that neuromuscular junctions, which most probably also contain dystrophin, are established in urodeles near the ends of the myofibers as shown by histochemical localization of AChE activity or fluorescent bungarotoxin detection of AChRs. In the stump transition zone close to the tail amputation level where tissue regeneration of injured muscle fibers took place, dystrophin staining located on the cytoplasmic surface of myofibers progressively disappeared during the dedifferentiation process which seemed to occur during muscle regeneration as suggested by electron microscopy. Furthermore, double labeling experiments using anti-dystrophin and anti-laminin antibodies showed a good correlation between the remodeling processes of the muscle fiber basal lamina and the loss of dystrophin along the sarcolemma of damaged and presumably dedifferentiating muscle cells.


Development of fetal thymocytes in organ culture: effect of corticosteroids.

Corticosteroids affect the development of fetal foregut-derived organs in which epithelial-mesenchymal interactions are associated with the developmental process. The thymus is one such organ and is profoundly sensitive to corticosteroids when mature. In this study corticosterone (CS) effects on fetal thymocyte development were investigated using a fetal thymus organ culture system which allows the growth, differentiation, and function of developing thymocytes to be monitored in vitro. CS inhibited, but did not block growth of fetal thymocytes, although the appearance of mature thymocytes was inhibited, similar to previously reported effects of interleukin 2 (IL2). CS enhanced the proportion of Mac1+, Ia+ and FcR+ cells and maintained high levels of IL2 receptor (IL2R) positive immature cells. Functional cytotoxic cells were detected in CS-treated organ cultures which expressed a Thy 1-, CD8- phenotype, atypical for thymus derived killer cells. While this cytotoxicity may be stimulated by CS, it could simply be due to a relative depletion of the main pool of thymocytes. These cytotoxic cells may have a role in directing apoptotic mechanisms occurring during thymocyte development.


Cyclic changes of membrane conductivity in fertilized and activated eggs of teleost (Misgurnus fossilis) and their relation to the cell shape.

Oscillations of membrane ionic conductivity, with a period similar to cell cycle duration, were observed in fertilized and activated loach (Misgurnus fossilis) eggs. In cleaving eggs the decrease in conductivity coincided with mitosis. Synchronously with the oscillations of membrane conductivity in activated as well as in fertilized eggs, rhythmic changes in blastodisc shape occurred. The blastodisc rounded up during the period of increasing membrane conductivity and flattened while conductivity decreased. Scanning microscopy of fertilized and activated eggs revealed differences in the surface relief of rounded and flattened blastodiscs.


Aminopeptidase activity levels during axonal and dendritic growth in the rat brain.

Brain aminopeptidase activity has been suggested as a candidate for the regulation and biotransformation of several neuropeptides. In this paper, changes in Lys- and Leu-aminopeptidase activities in rat brain hemispheres, cerebellum and medulla were examined in 1-, 3-, 5- and 7-days postnatal subjects. Aminopeptidase activities were studied by measuring the rate of hydrolysis of the artificial chromogenic substrates Lys- and Leu-2-naphthylamides (fluorimetrically detected in triplicate). Both enzyme activities show a decrease on the 3rd day of life followed by increases on the 5th and 7th day postbirth. It is suggested that these activities could play a part in the neurochemical changes that take place during axonal and dendritic growth in the rat brain.


The metabolism of microinjected inositol trisphosphate in Xenopus oocytes.

Microinjection of inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) into Xenopus oocytes evokes a complex physiological response composed of a transient and a slow depolarizing chloride current. We investigated the relationship between intracellular levels of Ins(1,4,5)P3 and the kinetics of the physiological response. Microinjected Ins(1,4,5)P3 was slowly degraded following first order kinetics of disappearance (t1/2 = 10 min). The degradation products were inositol bisphosphate (InsP2), inositol monophosphate (InsP) and inositol, as well as inositol tetrakisphosphate (InsP4). The rate of degradation of injected 3[H]-Ins(1,4)P2 was much greater (t1/2 = 3 min), indicating that the conversion of InsP3 to InsP2 may be the rate-limiting step in the degradation process. The slow degradation of 3[H]-Ins(1,4,5)P3 was not a result of its conversion to Ins(1,3,4)P3 since no accumulation of InsP3 was observed within 10 min of microinjection of 3[H]-Ins(1,3,4,5)P4. Activation of protein kinase C (PK-C) with a phorbol ester transiently increased the rate of conversion of 3[H]-Ins(1,4,5)P3 to InsP2. This, however, did not significantly affect the overall kinetics of 3[H]-Ins(1,4,5)P3 disappearance. Our results indicate that the kinetics of Ins(1,4,5)P3 degradation do not correlate well with the termination of both the rapid and the slow components of the physiological response. The termination of the slow component of the response, however, may be related to the decay of Ins(1,4,5)P3-induced 45Ca efflux, which lasted about 10 min.


Is physical working capacity determined by optimal magnesium concentration?

Two lines of research originated in the mid-seventies; one attempted to gauge the effect of strenuous effort on serum magnesium concentration (S-Mg) and the second, the effect of S-Mg on the indices of physical working capacity. In apparently healthy trained young Israeli men, long-term studies of the effect of strenuous effort on S-Mg showed that after a moderately strenuous effort (70 km forced march), there was a decrease of S-Mg which became statistically significant after 72 h, whereas after a severely strenuous effort (120 km forced march), the decrease was biphasic, being significant after 1 h, with a second fall after 72 h. In repeated experiments, the decrease of S-Mg was found to persist over time parallel 1. Since chronic lowering of S-Mg signifies a concomitant lowering of intracellular Mg content, these findings showed that Mg deficiency was a sequel to strenuous effort. Studies of the effect of S-Mg on the indices of physical working capacity showed that: (1) S-Mg determines the maximal voluntary muscle contraction force (MVC); (2) S-Mg affects, among other things, the maximal aerobic capacity (VO2max). The estimated daily Mg intake in the Israeli population is inadequate and a widely prevalent marginal to overt Mg deficiency is found in apparently healthy Israelis. It is proposed that an optimal physical working capacity in the Israeli population will be achieved only under conditions of Mg saturation of metabolism. Studies to validate this hypothesis are under progress.


Sudden death of athletes: is it due to long-term changes in serum magnesium, lipids and blood sugar?

In young, apparently healthy, trained Israeli men, strenuous effort was reported to give rise to persistent magnesium (Mg) deficiency and a parallel long-term increase of cholesterol, triglycerides and blood sugar parallel 1-3. The relationship of Mg deficiency to the pathogenesis of cardiovascular disease has been increasingly documented during the last decade. Several authors have highlighted the phenomenon of sudden deaths in sport and have suggested that it is associated with cardiovascular disease. The association is discussed between Mg deficiency and increase of blood lipids and sugar, found as a sequel to strenuous effort, and cardiovascular morbidity and mortality risk reported in athletes. It is postulated that sudden death of athletes and other intensely training individuals during exertion, is mediated by the deleterious cardiovascular effects of persistent magnesium deficiency and the resultant hyperlipaemia and hyperglycaemia, which, as we have documented, follows strenuous effort.


Different degree of ileal colonization by segmented, filamentous bacteria in two strains of mice.

Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic inhabitants of the ileum of various animal species. Outbred Swiss (Cpb:SE) mice have significantly higher degrees of SFB colonization than do inbred BALB/c mice. The present studies were carried out to identify determinants of this strain difference. In a cross-fostering experiment it was shown that SFB colonization of the pups is determined by the strain of the pups themselves rather than by the strain of the nursing dam. Thus, maternal effects may not be involved in SFB colonization. In a cross-infecting experiment using germ-free and SFB-positive animals of the two mouse strains, it was found that ileal SFB colonization is determined by host characteristics rather than by origin of the SFBs. Thus, SFBs that are specific for a given mouse strain may not exist in the two strains of mice. It is concluded that the mouse strain difference in SFB colonization is determined by host characteristics, which probably have a genetic basis.


Urinary characteristics of the Cape porcupine Hystrix africaeaustralis: effects of photoperiod and temperature.

The Cape porcupine Hystrix africaeaustralis is a large (11-18 kg), nocturnal, burrowing and group-living rodent. It experiences a metabolic response to seasonal acclimatization and is a hind gut fermenter. Changes in the urinary electrolyte and free urinary catecholamine concentrations of Cape porcupines were related to combined changes of ambient temperature and photoperiod regime. Three groups, A) Ta = 25 degrees C, 12L:12D; B) Ta = 32 degrees C, 16L:8D; C) Ta = 10 degrees C, 8L:16D, were studied to assess the influence of seasonal acclimatization on urinary bicarbonate and catecholamine concentrations. Urine volume was significantly (p < 0.001) higher in group C than in the other two groups. In groups B and C urinary pH was above 7 and this was associated with high concentrations of HCO3-. The total amount of catecholamines was higher in groups B and C than in group A. It is apparent that seasonal acclimatization of the Cape porcupine is also reflected by these parameters.


Changes in colonic mucins of germfree rats in response to the introduction of a "normal" rat microbial flora. Rat colonic mucin.

In order to determine the influence of bacterial colonization on amount and composition of colonic mucins, germfree male AS/Ztm rats were colonized with a rat specific intestinal flora for different times (2, 7, 14, 21, 28, 35, 120 days). The amount of colonic mucins was determined by gel filtration on Sepharose CL-4B; the relative amount of acidic mucins was calculated after ion exchange chromatography. In addition, cecal weight and dry matter of feces were monitored. While germfree and SPF rats revealed similar amounts of colonic mucins (7.0 vs. 7.2 mg mucin/300 g body weight), the initial phase of association was characterized by considerably decreasing values. After four weeks of association, the total amount of colonic mucins had almost equalized in the two groups. The amount of acidic mucins, having decreased during the first three weeks of colonization, rendered values comparable to the SPF mucins after four months of adaptation. Cecomegaly in germfree rats disappeared within the first two days, while solidification of the intestinal content occurred within four months. Mucin losses during initial phase of association are attributed 1. to the disappearance of the cecal mucin pool, and 2. to the mucin degrading activity of some bacterial strains known to be present in the intestinal flora. Further development is conducted by a stimulation of mucin secretion, described to follow the colonization. The initially increased secretion of neutral mucins is attributed to a pronounced release of immature mucin glycoproteins, while the shift to more acidic mucins is considered to result from stimulated secretion as well as from a selective bacterial degradation of neutral mucin components.


The mixed lipoxygenase/cyclooxygenase inhibitor SK&F 105809 reduces cerebral edema after closed head injury in rat.

Closed head injury in rats induces edema formation, which is indicated by a decrease in cerebral specific gravity and an increase in water content. We previously described the activation of the eicosanoid metabolic cascade, namely, activation of PLA2 and accumulation of products of both 5-lipoxygenase (5-LO) and cyclo-oxygenase (CO) in the same model of head injury. The present study was designed to determine the effect of a novel drug, SK&F 105809, a dual inhibitor of 5-LO and CO on cerebral edema formation after head injury in rats. Rats, under ether anesthesia, were subjected to sham operation or trauma induced by weight-drop device impacting over the left calvarium. One group of traumatized rats received 0.9% saline and served as control and two other groups were treated with SK&F 105809, 20 or 30 mg/kg, i.p. immediately after the impact. In one group treatment was repeated additionally 2.5 h post-trauma. Four hours after trauma, rats were sacrificed and brain edema was evaluated. SK&F 105809 treated rats which received 30 mg/kg had significantly less brain edema, as measured by both gravimetry and water content, at 4 h after trauma. The lower dose, 20 mg/kg, had no effect. Our results suggest that treatment with a mixed 5-LO/CO inhibitor shortly after head injury will result in less brain edema and ultimately improved functional outcome.


Oligonucleotide fingerprinting in Xiphophorus melanoma. Detection of a melanoma associated DNA modification.

Oligonucleotide fingerprints have been generated from fish melanomas and were compared to the constitutional multilocus patterns from normal brain DNA of the same individual. In 3 out of 8 cases additional bands were observed in the tumor DNA. This phenomenon can only be explained satisfactorily by so far unknown modes of DNA modification.


Life expectancy, its relation to sexual activity and body weight in male inbred mice.

Body weight of male mice of five inbred strains caged in groups of five was determined three times between the ages of 80 and 100 days, representing the individual fully grown body weight. Sexual activity of each mouse (number of ejaculations and intromissions) was estimated under competitive conditions between the ages of 120 and 150 days in eleven repetitions. Within all inbred strains only about half of the males displayed sexual activity when confronted with an estric female. The other do not. The animals remained in their cage groups until natural death after 727 +/- 215 days (C57BL/6), 638 +/- 260 days (BALB/c), 630 +/- 187 days (CBA), 560 +/- 230 days (DBA/2) and 317 +/- 62 (AKR) days. Only amongst the sexually active animals did individual life span correlate with the number of ejaculations. This was seen in C57BL/6, CBA and DBA/2. Particularly sexually successful animals, carrying out the most ejaculations, live 10-20% longer than their (subdominant) competitors displaying less sexual success. Sexually inactive males (characterised by no ejaculations and less other sexual activities) show that this characteristic of their personalities imposes no limitation upon their life expectancy. Fully grown body weight and the individual life span correlates within the strains DBA/2, C57BL/6 and BALB/c. Medium-sized animals have a greater life expectancy than small or large ones.


Examination of brown adipose tissue thermogenesis of glutamate-induced obese rats by differential temperature measurements.

Differential temperature measurement between interscapular brown adipose tissue (BAT, Tbat), rectum (Trect) and a subcutaneous point in the back left of the vertebral column (Tsc) was useful for examination of BAT-thermogenesis in glutamate-induced obese Wistar-rats. Positive temperature gradients Tbat-Tsc pointed to a basal BAT-thermogenesis, whereas negative temperature gradients Tbat-Trect did not indicate that heat production in lean and obese rats. One may conclude from this, that inclusion of subcutaneous points outside the BAT improves sensitivity of differential temperature measurements for BAT-thermogenesis. Basal temperatures Tbat, Trect and Tsc were reduced in obese rats compared to lean rats, although thermoinsulation of obese rats is improved on account of their high fat content. This points to a diminished heat production in obese rats. Cold exposure at 4 degrees C elicited an increase of temperature gradients Tbat-Trect in lean as well as in obese rats, with positive values found only in lean rats. However, positive values Tbat-Tsc were calculated for both groups. Increases were noted only in lean rats. Injection of noradrenaline (0.5 mg/kg i.m.) was followed by positive temperature gradients Tbat-Trect and increased positive values for Tbat-Tsc, pointing to a remarkable activation of BAT-thermogenesis in lean and obese rats. These findings confirm, that glutamate-induced obese rats preserved the ability to activate BAT-thermogenesis. There were, however, hints of reduced heat production in BAT of obese rats, thus contributing to obesity despite normophagia.


[Acute early rejection in renal transplantation].

The incidence of early acute rejection (first two months after surgery) was evaluated in a group of 150 kidney transplants, receptors, who were followed for more than three months. Ninety nine were transplanted with kidney from a cadaver donor and 51 with living donor. One hundred forty two patients were treated with triple immunosuppression therapy (cyclosporine, prednisone and azathioprine). The incidence of early acute rejection was significantly higher in cadaver kidney receptors (34% vs 19.6%, p = 0.04. Fisher exact test). However, early rejection did not have demonstrable influence in graft or patient survival or in the follow-up graft function. Graft and patient survival were not affected by the severity of the rejection episode.


[Retrospective diagnosis of a sample of patients discharged with a diagnosis of schizophrenia].

A retrospective diagnosis was obtained from a sample of 300 patients discharged from the Psychiatric Hospital of Maracaibo (Venezuela), with the clinical diagnosis of schizophrenia. These medical records were evaluated under DSM-III criteria, by two psychiatrists using structured formats. We found that 46.3% of the patients met the criteria corresponding to the schizophrenic disorder; from the remaining 53.6%, 19.6% did not have enough information to be included in this category, and 34.6% was classified under other psychiatric disorders. Of the patients with schizophrenic disorders, 61.2% were male, single, and Venezuelan citizens; 84.9% began their clinical manifestations during the second or third decade of their lives; 89.9% received education. The predominant symptomatology was impairment in social relations (93.5%), deterioration in hygiene and self- care (92.5%), impairment in functioning (87.1%), illogical thinking (86.3%), with predominant persecutory delusions, auditory hallucinations, dialogue hallucinations (84.6%), grandiose delusions (48.2%), and personal experiences of corporeal changes (45.3%). Affective symptomatology were present in all patients and the predominant subtype was the paranoid, that was observed in 80.6% of the cases. Positive signs of this disease in family history were present in 41 percent of the cases. Our findings confirm the necessity to unify criteria concerning the diagnosis of mental disorders, as it became evident that the variability in diagnosis, makes more difficult the psychiatric research in our country.


Observation on a human intentional poisoning case by the organophosphorus insecticide fenthion.

A case of acute poisoning by oral ingestion of fenthion is reported. Plasma cholinesterase activity and fenthion whole blood concentration were thoroughly evaluated during the therapeutic intervention that consisted in administration of atropine, toxogonine and fresh plasma. Correlation studies between clinical signs, cholinesterase activity and fenthion levels revealed that pChE activity was not as helpful as the patient's clinical status in determining when the atropine infusion could be stopped. Moreover pChE was also useless in signaling sudden relapses. It is concluded, based on this case, that supportive care combined with antidotal therapy remains the cornerstone of treatment specially in severe acute poisoning cases.


[Thoracic ectopic kidney. Report of a case].

We describe a 23 months old boy who presented a clinical picture of bronchial hyperreactivity and a tumoral intrathoracic mass in a plain thorax X-ray, receiving for these reasons, antibiotic therapy during 30 days. Intravenous pyelography and ultrasonography revealed the presence of an ectopic intrathoracic kidney. Since this renal anomaly is usually asymptomatic and do not requires treatment, it is necessary to suspect this abnormality whenever an intrathoracic mass is found.


[The distribution of mutans streptococci and lactobacilli depending on the caries prevalence in 11- to 12-year-old children].

20 Korean children, aged 11 to 12 years, participated in this study with the aim to compare the microbial composition of plaque samples in order to estimate, which genera (lactobacilli, streptococci) or species are associated with coronal caries. Significant differences in the microbial composition of plaque samples between children with healthy and carious dentitions were found. S. mutans (c, e, f) was dominating under Mutans-streptococci.


[The synthesis of collagenous and noncollagenous proteins by cells from the periodontium].

Synthesis of collagenous and noncollagenous proteins by cells originating from the alveolar bone (AB-cells) and from the periodontal ligament (PDL-cells) of 8 minipigs was analyzed in primary cell cultures. Incorporation of 3H-proline into proteins recovered from cell extracts showed, that 13.7% of protein synthesized by AB-cells and 8.0% of protein synthesized by PDL-cells were collagens. In both cell lines relative amounts of collagens synthesized decreased significantly on subculturing (AB-cells: 9.3%, PDL-cells: 6.0%). Preincubation of 2nd subculture AB-cells with beta-glycerophosphate had no significant effect on collagen synthesis. Considering the fact that relative amounts of collagen recovered from cell extracts represent only 10-20% of collagen recovered from whole culture (i.e. cells and culture medium), we suggest that collagen synthesis is an important component of in vitro-protein synthesis of cells originating from the alveolar bone and the periodontal ligament.


[In-vitro research on the marginal adaptation of composites with the use of different dentin adhesives].

The aim of this investigation was the check and evaluation of 7 various dentin adhesives regarding their influence on the connection between dentin resp. enamel and composite filling. For that cylindrical cavities in dental crowns (enamel cavities) and roots (dentin cavities) were prepared and treated with dentin adhesives and composite materials. One part of the test teeth was subjected to loads storage in aqueous solution and thermocycling. The marginal adaptation of the composite filling was checked by means of the dye penetration test. The evaluation was made after cutting the teeth in the stereo microscope TECHNIVAL 2 (Carl Zeiss Jena) at 16-resp. 25 magnifications and defined criteria. The fillings in cavities bound by enamel exhibited a very good marginal adaptation of the composite. The location of the dentin cavity (crown or root dentin) had no significant influence on the fitting of the filling. A clear penetration of dye could be observed with the fillings in the dentin with and without adhesives, which considerably intensified after thermocycling. Best results with regard to the marginal adaptation were obtained with Scotchbond 2, Mirage-Bond and Cavex-Clearfil-Newbond. A restoration without a marginal gap was not possible.


[Legionellae in dental units--a hygienic risk?].

Water samples were collected from the hot water systems and from dental units in 12 dental offices of Dresden and cultured for legionellae. From seven (58%) hot water supplies and from dental units in 6 (50%) offices legionellae could be isolated. To asses the hygienic risk for dental staff we studied the prevalence of antibodies against Legionellae in serum samples of 113 dentists, 105 dental nurses and 17 dental technicians. In comparison with a control group of healthy people (132 women, 161 men, 20-80 years) living in the Dresden area, dentists have had a higher prevalence of antibodies against legionellae. In a lesser degree this was the case in sera of dental nurses and dental technicians. There were substantially differences in the prevalence of legionellae antibodies in different facilities. The incidence of positive antibody titers rises with the duration of occupation. None of the dentists with high antibody titers have had a story of pneumonia in their history of life. Thus a higher risk for dentists to acquire legionnaires' disease during their professional duty cannot be established.


[Oral leukoplakias--a histopathological and retrospective study].

In a retrospective study 85 patients of our department with clinical oral leukoplakia occurring between 1980 and 1985 were checked histologically and reclassified. Compared to other studies and unusual high malignant transformation rate (14.1%) was found which seemed to be depended on the high rate of radiated patients. Four of twelve patients were healed due to early diagnosis and radical surgery performed consecutively. Using these data as a basis the different courses and therapies are demonstrated.


[The treatment results in the differential therapy of mouth carcinomas. A retrospective study of the patient population of the Oral Surgery Department (1978-1986) of the University of Göttingen].

In a retrospective observational study on malignomas of the oral and maxillofacial region a data material of 157 patients has been analyzed. Results of the therapy and the course of disease are presented. The average delay between the appearance of the first symptom respectively the beginning of a therapy and the treatment in a specialized department for maxillofacial surgery runs up to 4.3 month and 2.8 month respectively. This dissatisfying situation is corroborated by the results for TNM categories with more advanced tumors. Only 16.6% of the patients belong to the T1 category, 42% to the T2 category and 35.7% to the T3 category. In 30.5% of cases tumor cells are found in cervical lymph nodes. Correlations between the size and the localisation of the primary tumor and metastases are obviously. The results of treatment are presented in form of survival curves and curves for times of no recurrence. There is no advantage in a combination of chemotherapy and surgery instead of single surgical therapy. In cases of more advanced tumors in T2 and T3 category there is no recurrence after 2 years in 70% of surgical treatment and in 69% of combined surgical treatment and chemotherapy. The censored estimated survival rate after 5 years in cases of surgical treatment comes to 63%, in cases of combined therapy to 62%. The consistent radical neck dissection is of distinctive signification. Recurrencies in the neck dissection region appear in 8.2% of patients.


[The gingival margin incision as the surgical approach in cleft jaw osteoplasty--the technic, the healing process and postoperative complications].

Marginal incision became a common surgical approach in periodontal surgery because of its good healing results. Since 1983 we use this incision for bone grafting in cleft palate patients. Out of 120 cleft palate patients which had marginal incision for bone grafting, 9 developed local dehiscence, 3 times in combination with partial loss of the cancellous bone transplant. We saw one total loss of the transplant caused by infection. The good results of primary wound healing, the absence of horizontal scars and the possibility of mobilisation of epithelium from the cleft region to cover the transplant with mucosa from the alveolar process are the advantages of this procedure.


Cloning and nucleotide sequence of chloroplast psaA gene from sorghum.

The 6.7 kb EcoRI fragment containing the sorghum chloroplast psaA gene was cloned. The restriction endonuclease map and the nucleotide sequence were determined. The length of the determined nucleotide sequence was 3080 bp, of which the psaA coding sequence was 2253 bp, which encoded a polypeptide of 750 amino acids with a estimated molecular weight of 83000. The homologies of this psaA gene of sorghum with those of maize, rice and spinach were 99.4%, 96.3% and 89.4%, respectively, and the homologies of the deduced polypeptide sequences were 99.3%, 98.0% and 95.7%, respectively. We found that a difference in the profiles of the hydrophobic distribution of P700 apoproteins existed between C4 and C3 plants due to a change occurred at the 493th amino acid (C4 plants: Gly; C3 plants: Arg or Ser).


Regulatory mode of the pac gene expression.

1.65kb HindIII-BgIII DNA fragment containing pac operator was cloned from plasmid pPA4 to pBR322 at HindIII-BamHI sites, the resultant plasmid pPA41 was transformed into E. coli D816 carrying an intact pac operon on its chromosome, then the effect of operator titration was estimated. It was found that the penicillin acylase activity in E. coli D816 (pPA41) cells was higher than that of in E. coli D816 cells. The operators on high copy number plasmid pPA41 competed for the regulatory proteins with the single copy operator on the chromosomal pac operon, thus the expression of the pac gene was enhanced, because the free regulatory proteins were decreased by operator titration. The results of RNA-DNA hybridization showed that the cellular pac mRNA concentration was parallel to the penicillin acylase activity, and the pac mRNA in E. coli D816 (pPA41) cells was much higher than that of in E. coli D816 cells. These results indicated that the expression of pac gene was negatively controlled at transcriptional level.


Cloning, characterization and partial sequence analysis of the 5'-flanking region of bovine alpha-sl casein gene.

We have isolated a clone from a EMBL3 constructed bovine genomic library using a PCR-generated DNA fragment as a probe covering-660bp to + 158 bp of boving alpha-sl casein gene. The results obtained from hybridization assay, restriction endonucleases map and partial DNA sequence analysis indicated that the cloned fragment spanned 5.7kb of the first part of the gene and 8.0 kb of its upstream flanking region. Some divergent restriction endonuclease recognition sites and a few mutations and deletions were found in exons, introns and 5'-flanking region of the gene we cloned when compared with the PCR-generated fragment and those which had been published [6,10]. All the deletions occurred at repeat sequences.


Utilization of the protoplast fusion technique to explore directional altering lincomycin producing microorganism.

Interspecific protoplast fusion between Streptomyces lincolnensis var. lincolnensis (LM gamma, CTC gamma, producing lincomycin) protoplast and Streptomyces aureofaciens (LM gamma, CTC gamma, producing chlorotetracycline) protpolast which had been treated with UV radiation 40 min for inactivation was performed with PEG 6000, the fusants were obtained by directly selecting from the regeneration plates containing CTC 50 micrograms/ml, the fusion frequency was about 9.05 x 10(-5). From many fusants, only 4 stable recombinants were obtained. These species produced antibiotics which are different from lincomycin and chlorotetracycline. Preliminary identification of the antibiotic synthesized by one of the recombinants suggests that its basic structure might be similar to that of lincomycin. The fermentation product of recombinant No. 2 showed new chromatographic spot which is similar to that of clindamycin. Though the products remain to be identified further, this strategy seems to be worthy of exploring for screening new antibiotics.


A perfusion system for high productivity of monoclonal antibody by hybridoma cells in a CelliGen bioreactor.

DA4-4 (ATCC HB57) is a shear sensitive mouse-mouse hybridoma cell, producing an IgG1 monoclonal antibody against human IgM. It was grown successfully in a perfusion propagation system consisting of a 1.5 CelliGen stirred bioreactor and a hollow fiber cartridge. CelliGen system produced low shear force and cells could grow well at high agitation of 150 rpm. The culture was maintained for 40 days and cell number reached 20 x 10(6)/ml. Maximal monoclonal antibody concentration was 4.75 mg/ml. This system produced about 1.0 g of antibody every day at its peaks.


Purification and partial characterization of an antibacterial protein LCIII.

Total proteins were precipitated by (NH4)2SO4 from the overnight culture supernatant of antagonistic bacterium Bacillus subtilis A014, applied to CM52 column and separated into three main peaks. The preparation of peak III showed to inhibit specifically the growth of rice bacterial blight pathogen Xanthomonas compestris pv. oryzea was further purified with Mono S column on FPLC and named antibacterial protein LCIII. The molecular weight of this protein is 26915Da, pI = 9.12. Analysis of amino acid composition was revealed to be rich in glycine, threonine and serine, and devoid of proline. Twenty-eight amino acids of N-terminal were sequenced by the Edman degradation and computer analysis of this partial sequence showed that antibacterial protein LCIII is a novel one.


Studies on kinetic model of vitamin C two-step fermentation process.

This paper aims at analyzing the bioconversion process from L-sorbose to 2-Keto-L-gulonic acid with the aid of the growth factor assumption. Fermentation mechanism is discussed after making necessary simplifications. A model is established for this second step fermentation process. Nonlinear optimization together with Runge-Kutta method, are used to obtain model parameters. Results of computer simulation agree with experimental data to show the reliability of the kinetic model.


Estimation for model parameters of batch fermentation kinetics.

Based on the widely accepted mathematical model of fermentation kinetics, an analytical solution is deduced in this paper. To describe the feature of batch fermentation, the parameters of the fermentation kinetics in the analytical solution (i.e., mumax, Ks, beta, YG, YP, and m) are estimated at one strike with POWELL optimization algorithm coded in FORTRAN-77. The experimental data in the example is quoted from a batch lysine fermentation process using Corynebacterium glutamicum. The result shows that: 1) the calculated values of the mathematical model agree very well with the experimental data; 2) the synthesis rate of lysine depends on both the growth rate and the concentration of the biomass.


Screening of bacterial strains producing maltotetraose-forming amylase and the conditions for enzyme production.

The authors isolated 1380 bacterial strains from 290 soil samples collected in China and 490 strains were received from other research teams in this institute. By screening 707 strains showed starch-hydrolyzing activity. By further screening and paper chromatographic test, three strains with maltotetraose as the major product were obtained. The maltotetraose was further confirmed by treatment with beta-amylase splitting to maltose and with glucoamylase to glucose. The most promising strain was 537.1, which produced maltotetraose about 90% (w/w) in the starch hydrolysate. While the other two strains produced maltose and maltotriose besides maltotetraose. Strain 537.1 was tentatively identified as Alcaligenes sp. The optimum conditions for enzyme production were as follows: medium composition: 1.5% maltose; 0.5% peptone with initial pH of 7.0-7.5; cultured at 27-28 degrees C for 48 hours on rotary shaker. The culture supernatant of the strain 537.1 can hydrolyze starch and different kinds of cereal flour with a high yield of maltotetraose in the hydrolysate.


Dyes as teratogens.

The main fats and problems of the role of dyes in prenatal pathology are reviewed. The first section deals with the practical aspects related to teratological screening of industrial dyes (including also the results obtained in this laboratory). In the second section, various aspects of azo-dye teratogenesis are largely discussed, including also the experimental contributions of this laboratory. Concluding remarks are made with respect to the importance and to the perspectives of this field of research.


The electron microscope comparative study of the thyroidian cell in Graves' disease and of the normal human thyroidian cell.

The comparative study of the thyroidian cell in Graves' disease and of the normal human thyroidian cell allows interesting findings about the changes of the thyroidian tissue in abnormal conditions. Histologically in Graves' disease appears a diffuse and general hyperplasic and hypertrophic process, affecting all the component parts of the thyroid cell. The thyroid cell appears to be high, columnar, with a retained nucleus/cytoplasm ratio. The cellular apical pole is covered by a thin plasmatic membrane with many microvilli. The cytoplasm has a foamy, distended aspect, established by the general hypertrophic and hyperplasic process of the cell constituents, respecting the normal arrangement of the normal cell. In electron microscopic images mitochondrias look like round and very distended formations with evident christae and a twofold membrane. The vesicles of rough endoplasmic reticulum are very closed to the mitochondrias and the Golgi apparatus represented by vesicles and bags and are situated around the nucleus. The secretion granules are abundant at the apical pole, the vesicular bodies are bigger and very numerous the nucleus has big amounts of euchromatin. This aspect is very similar to the exagerated function of the thyroid cell in Graves' disease.


Urethral and neobladder cytologic survey in patients with total cystectomy.

Fourteen patients with total cystectomy and sigmoidian ureterostomy, 10 with cutaneous ureterostomy and 6 with substitution bladder were studied from the cytologic point of view; from all patients samples of voided urine, urethral and neobladder washing were taken and smears stained with blue polychrom-tanin Drăgan; the smears which belong to the last group were cytochemically investigated, too. From morphohistochemical point of view biopsies taken from cases with recurrences and one case with substitution bladder which died in the 10th day after surgery were studied. The cytologic study revealed two recurrences: one urethral and one at the pelvis level at 18 and respectively 4 months from total cystectomy, both being transitional cell carcinoma. Cytologic and histochemical aspects of the intestinal wall used as neobladder are described, revealing epithelial modifications and chronic inflammatory infiltrate with marked decrease of mucous synthesis. The importance of urinary cytology in oncologic survey of these patients is discussed.


Histochemical study on the activity of some oxidative and hydrolytic enzymes in the normal human endometrium blood vessels and at various intervals after applying the intra uterine contraceptive device.

The paper intends to study the cytoenzymological modifications of the human endometrium blood vessels after applying the intrauterine contraceptive device for a long period of time. The results were different according to the: type of the enzyme-ATP-ase, Lactatdehydrogenase, Leucineaminopeptidase, NADH2-citochrome-c-reductase, the components of the blood vessel wall (intima, media, adventitia), the blood vessel diameter, the hormonal cyclic stage.


Morphometric study of cell populations in primary breast tumors and their lymph node metastases.

The study of nuclear parameters (long and short nuclear axes, nuclear axes ratio, nuclear area) revealed differences both between the primary breast tumors and their lymph node metastases and between the lymph nodes isolated from the same axilla. The results are discussed in terms of tumor progression.


Cytomorphological, ultrastructural and immunological characteristics of the ovialsyn fluid in seropositive rheumatoid arthritis.

Experiments have been performed on 15 samples of synovial fluid (SF) from patients with seropositive rheumatoid arthritis (RA) (Latex 1/280 and Waaler Rose 1/1024) versus 10 SF samples from patients with hydroarthrosis, used as control. By cytomorphologic studies, we determined the cellularity, ragocytosis and synoviocytogram of the SF cellular pellet and found out that rheumatoid SF is characterized by cytosis (9953/mm3), ragocytosis (70%) and polynucleosis (73%) whereas hydroarthrotic SF is characterized by lymphocytosis (54.6%). Ultrastructurally, rheumatoid SF ragocytes present numerous intracytoplasmic inclusions and phagolysosomes, a fact that certainly evidences an endocytotic activity. At the level degenerative of PMN cells, (6%), the experiments evidenced the presence of some lysis cytoplasmic plateau associated with the absence of cellular organelles, as well as an alteration of the granulofibrillar structure of the nucleus. We also noticed cellular debris consisting of partially destroyed cellular organelles. By immunologic studies we obtained seric pathologic values for CIC (mean = 108.05 U), IgM (mean = 420 Ul/ml), IgG (mean = 355 Ul/ml), anti DNA antibodies (mean = 405 U) and anti collagen II antibodies (mean = 558 U). As regards the seric complement activity of C1q and C3 fractions, it was higher (mean = 18.87 mg% and mean = 109.94 mg%, respectively) than in the SF (mean = 5.78mg% and mean = 30.83 mg%, respectively). Corroborating the cytomorphological, ultrastructural and immunological data, we could better explain the lesional types examined and emphasize the importance of the immunomorphological changes in RA diagnosis.


Multiple inverted papilloma of the urinary bladder associated with glandular metaplasia of colic type. A case report.

A case of inverted papilloma of the urinary bladder associated with glandular metaplasia is presented. A bladder urothelial carcinoma was suspected after clinic and endoscopic findings, but the diagnosis was established only on histological picture. Morphological and histochemical peculiarities of the lesions are described, considering the case being the first with such an association-according to our knowledge. The malignant potential of inverted papilloma and glandular metaplasia are discussed.


Dynamics of Golgi impregnation in neurons.

This paper describes the early stages of impregnation by the Golgi rapid method in sections and blocks of brain tissue. Aldehyde-fixed and potassium dichromate-treated sections of cerebral cortex were placed on glass slides and coverslipped. The dichromate solution was then replaced by a silver nitrate solution, and events taking place in the section were monitored and time-lapse recorded until the impregnation was interrupted and the sections subsequently prepared for electron microscopy. The tissue blocks, fixed and chromated in the same way, were placed into a silver nitrate solution for 30 min to 24 h and the progress of impregnation compared with the results obtained in the sections on the glass slides. Two basic modes of impregnation were observed, apparently in direct relation to the process of crystallization of silver chromate: crystals of silver chromate growing directly from the surface of the tissue into the nerve cell via its transected plasma membranes, and microcrystalline precipitate of silver chromate spreading into the nerve cell from nucleation centres dispersed in the tissue. The precipitate grows inside the cell as in a preformed channel until the cell has been filled. If the nucleation begins extracellularly, the precipitate extends into the narrow intercellular gaps. Electron microscopy showed that the crystalline precipitate consisted of multilamellar formations containing dense coalesced granules that did not cross plasma or endocellular membrane boundaries.


Kawasaki disease in an infant with cystic fibrosis.

The authors report a case of a 3-month-old infant with a very rare association: cystic fibrosis and Kawasaki disease. The clinical picture is atypical but cardiovascular signs consist of cardiomegaly, sick sinus syndrome and Q waves in D II, D III and AVF. The diagnosis is confirmed by the pathological changes found at the postmortem examination. The patient is the first case of Kawasaki disease reported in Romania.


Techniques for converting Golgi precipitate in CNS neurons into stable electron microscopic markers.

Direct electron microscopy of nervous tissue stained with the Golgi impregnation method is unsatisfactory because the cytoplasm of the cell bodies and processes of the impregnated neurons are completely filled with a compact precipitate of electron dense silver chromate. This precipitate entirely obscures the cytological details of the impregnated neurons. Because of its solidity and instability in aqueous solutions, the silver chromate is also a source of inconvenience during the preparation of the ultrathin sections. This review summarizes methods that have been developed with the aim of replacing the Golgi precipitate in CNS neurons with a more convenient electron dense material--for example, heavy metal salts or metallic particles. Conversion of the precipitate into a stable electron dense marker is done before the material is embedded for electron microscopy. The methods include lead, gold, and bromide substitution, treatment with ammonia, direct chemical reduction into metallic silver, and photoreduction of the silver chromate into silver through irradiation with ultraviolet light.


Electron microscopy of Golgi-impregnated interneurons: notes on the intrinsic connectivity of the cerebral cortex.

The Golgi-electron microscope technique has opened new avenues to explore the synaptic organization of the brain. In this article, we shall discuss basic methodological principles necessary to analyze axonal arborizations with this combined technique. To illustrate the applications of the method, we shall review the forms and distribution of the synapses in which the axonal arborizations of local cortical interneurons engage.


Application of the Golgi/electron microscopy technique for cell identification in immunocytochemical, retrograde labeling, and developmental studies of hippocampal neurons.

In this study the Golgi/electron microscopy (EM) technique has been used for an analysis of the fine structure, specific synaptic connections, and differentiation of neurons in the hippocampus and fascia dentata of rodents. In a first series of experiments the specific synaptic contacts formed between cholinergic terminals and identified hippocampal neurons were studied. By means of a variant of the section Golgi impregnation procedure, Vibratome sections immunostained for choline acetyltransferase, the acetylcholine-synthesizing enzyme, were Golgi-impregnated in order to identify the target neurons of cholinergic terminals in the hippocampus. It could be shown with this combined approach that cholinergic septohippocampal fibers form a variety of synapses with different target structures of the Golgi-impregnated and gold-toned hippocampal neurons. In this report cholinergic synapses on the heads of small spines, the necks of large complex spines, dendritic shafts, and cell bodies of identified dentate granule cells are described. The variety of cholinergic synapses suggests that cholinergic transmission in the fascia dentata is a complex event. Next, the Golgi/EM technique was applied to Vibratome sections that contained retrogradely labeled neurons in the hilar region of the fascia dentata following horseradish peroxidase (HRP) injection into the contralateral hippocampus. With this combined approach some of the hilar cells projecting to the contralateral side were identified as mossy cells by the presence of retrogradely transported HRP in thin sections through these Golgi-impregnated and gold-toned neurons. Our findings suggest that the mossy cells are part of the commissural/associational system terminating in the inner molecular layer of the fascia dentata. They are mainly driven by hilar collaterals of granule cell axons that form giant synapses on their dendrites. Finally, the Golgi/EM procedure was used to study the differentiation and developmental plasticity of hippocampal and dentate neurons in transplants and slice cultures of hippocampus. Under both experimental conditions, the differentiating neurons are deprived of their normal laminated afferent innervation but develop their major cell-specific characteristics including a large number of postsynaptic structures (spines). As revealed in thin sections of gold-toned identified cells, all these spines formed synapses with presynaptic boutons suggesting sprouting of the transplanted and cultured neurons, respectively. Altogether, the present report demonstrates the usefulness of the Golgi/EM technique, particularly of the section impregnation procedure, for a variety of studies requiring the identification of individual neurons at the ultrastructural level.


Progressive spastic paraparesis associated with human T-cell leukemia virus type I (HTLV-I).

Patients with progressive spastic paraparesis (PSP), commonly middle-aged women, are distributed throughout the country of Chile. During the three years from 1987 to 1990, we collected 83 cases of PSP from among 225 patients with various neurological diseases. The clinical picture was of a bilateral pyramidal syndrome, with sensory deficits in only 15.5% of the cases, and a slow illness progression in the majority of them. In patients with PSP, antibody to human T-cell leukemia virus type I (HTLV-I) was analyzed by enzyme linked immunosorbent assay (ELISA) and confirmed by western blot analysis. Forty-five (54.2%) patients were anti-HTLV-I antibody positive in cerebrospinal fluid (CSF) and peripheral blood. Among them, 2 patients had leukemia/lymphoma and one had Sjögren syndrome. In the laboratory study of seropositive PSP, mononuclear pleocytosis was found in 35.7%; there was an abnormal increase of the IgG index in 66.6% and an increase in CD2 in blood and CSF, and CD4 in blood. A delayed latency of somatosensory evoked potentials was observed in 90.9%. The neuropsychological study revealed a WAIS with a mean verbal IQ of 80.7 and a mean performance IQ of 84.8. The most impaired items were digit symbol and digit span. Seven subjects (18.9%) with anti-HTLV-I antibody were found among 37 relatives from 19 anti-HTLV-I positive cases of PSP.


Hypereosinophilic syndrome accompanied with necrosis of finger tips.

We report a case of hypereosinophilic syndrome (HES) with marked eosinophilia (59.7%) and mononeuritis multiplex (upper limbs and buttocks). Necrosis of the finger tips was the primary manifestation which simultaneously occurred on both sides. These clinical manifestations were improved dramatically by subsequent steroid therapy. Interestingly, an elevation of serum tumor necrosis factor (TNF) was observed. These findings suggest that TNF may play a role in the etiology of necrosis of the finger tips.


Charcot-Marie-Tooth disease with diaphragmatic weakness.

A 61-year-old man, who suffered from Charcot-Marie-Tooth disease (CMT) for 44 years, was evaluated for the respiratory disorder. He had diaphragmatic dysfunction induced by phrenic nerve disturbance. In this patient, central type apnea and hypopnea related to diaphragmatic weakness occurred during REM sleep, which induced accessory inspiratory muscle inhibition. Respiratory muscle dysfunction had not been generally recognized in CMT until recently, but its significance should be emphasized.


Crohn's disease associated with diffuse lymphoid hyperplasia of the large intestine: a possible role of the lymph follicle in HLA-DR antigen expression on epithelium.

A 14-year-old girl diagnosed as Crohn's disease had lymphoid hyperplasia throughout the large bowel. Biopsy specimens from the lymphoid hyperplasia demonstrated non-caseous granulomas within the lymph follicles. An immuno-histochemical study of biopsy specimens showed that HLA-DR antigens were expressed on epithelium close to the lymph follicle, which was observed in all specimens containing the lymph follicle. This case provides evidence for the importance of the lymph follicle in the etiopathogenesis of Crohn's disease by demonstration of non-caseous granulomas within the lymph follicle and expression of HLA-DR antigens on epithelium close to the lymph follicle.


Acquired chronic pure red cell aplasia successfully treated with intravenous pulse methylprednisolone therapy.

A 65-year-old male patient developed acquired chronic pure red cell aplasia (PRCA) associated with hypergammaglobulinemia and positive Coombs' test during the treatment of eosinophilic pneumonia with prednisolone (PSL). His PRCA was treated with oral PSL at a dose of 60 mg/day for 3 weeks, but anemia further progressed. Immediately after high-dose intravenous pulse methylprednisolone therapy (1 g/day for 3 days) however, reticulocyte crisis occurred and his anemia rapidly improved. He has been in complete remission under a maintenance dose of PSL for more than 2 years. This patient indicates that high-dose intravenous methylprednisolone therapy is one of the useful treatments, not only for constitutional PRCA, but also for acquired chronic PRCA.


Malignant lymphoma localized in the abdomen: detection of Ig gene rearrangement from the specimen obtained by percutaneous lymph node biopsy.

A 32-year-old man was admitted to our hospital because of lumbago and an abdominal mass revealed by abdominal ultrasonography. Abdominal CT scan and MRI revealed multiple para-aortic lymph node swelling involving several arteries and veins. As there was no superficial lymph node swelling, percutaneous lymph node biopsy was performed under ultrasonographic guide. Although non-Hodgkin's lymphoma, diffuse, small cell type was suspected by light microscopic study, the monoclonality of the lymphocytes in the obtained specimen was not clear by the immunohistochemical study. Southern blot hybridization analysis of the biopsy specimen revealed the rearrangement of IgH and IgL (lambda) chain gene, indicating the existence of monoclonal proliferation of lymphoma cells. The DNA analysis appears useful for the differential diagnosis of lympho-proliferative diseases.


Medial longitudinal fasciculus syndrome associated with a subdural hygroma and an arachnoid cyst in the middle cranial fossa.

A 60-year-old man complaining of diplopia and vertigo showed bilateral medial longitudinal fasciculus (MLF) syndrome. The CT scan revealed a space-occupying lesion with watery fluid in the left cranial fossa, which was divided into two parts by a thin septum. Surgical trepanation was performed followed by 4 weeks of prednisolone therapy. He was completely cured 5 months later. The plausible causes of MLF syndrome relevant to preexisting space-occupying lesions are discussed.


Primary angiosarcoma of the right atrium detected by magnetic resonance imaging.

A 20-year-old woman with a primary angiosarcoma of the right atrium is reported. The patient had a cardiorespiratory arrest due to cardiac tamponade with bloody pericardial effusion. Magnetic resonance imaging (MRI) revealed a tumor, which was corroborated by selective coronary angiography. Open-heart surgery was performed. The tumor relapsed however, and she died four months after operation. The tumor was undetectable by echocardiography, but MRI demonstrated a heterogeneous mass with focal areas of high- and low-signal intensity in the right atrium, suggesting that MRI may allow characterization of cardiac tumors.


Successful treatment of levodopa-induced neuroleptic malignant syndrome (NMS) and disseminated intravascular coagulation (DIC) in a patient with Parkinson's disease.

After 9 years of treatment for Parkinson's disease, a 68-year-old woman developed the complications of neuroleptic malignant syndrome (NMS) and disseminated intravascular coagulation (DIC) while she was still receiving levodopa, bromocriptine and amantadine hydrochloride. The patient displayed a high fever (40 degrees C), impaired consciousness, marked systemic muscle rigidity, tremor and bloody stools. The diagnosis of NMS and DIC was made on the basis of the symptoms and the results of blood serological tests. The antiparkinsonian drugs that had been administered until her admission to our hospital were continued unchanged, while the NMS was treated with dantrolene sodium and the DIC, with nafamostat mesilate. Both of the above-mentioned therapies were effective. The present case is rare in that the patient developed NMS and DIC during treatment and not after the discontinuation of the antiparkinsonian drugs.


Carbamazepine-induced systemic lupus erythematosus-like disease.

A 14-year-old female developed systemic lupus erythematosus (SLE)-like symptoms, rash, fever, leukopenia and positive anti-nuclear antibody (ANA) two weeks after administration of carbamazepine (CBZ; Tegretol) used against benign Rolandic epilepsy. Clinical symptoms and leukopenia normalized after discontinuation of CBZ and administration of prednisolone at 40 mg. The cases of CBZ-induced SLE reported in the literature were reviewed.


A patient with severe iron-deficiency anemia and memory disturbance.

A 56-year-old woman presented with severe iron-deficiency anemia and memory disturbance. She had been in a state of severe iron deficiency for many years due to an unbalanced diet. Aerobic exercise test revealed an abnormal elevation of lactate and pyruvate reflecting mitochondrial dysfunction. After iron replacement therapy, WAIS verbal IQ score improved from 63 to 83, and levels of lactate and pyruvate on aerobic exercise test were normalized. We raise the possibility that severe and long-term iron deficiency anemia may cause memory disturbance due to mitochondrial dysfunction.


Insulin-dependent diabetes mellitus showing microangiopathic hemolytic anemia and chronic disseminated intravascular coagulation.

It has been reported that microangiopathic hemolytic anemia occasionally occurs in patients with severe diabetic microangiopathy. We report a case of insulin-dependent diabetes mellitus in whom microangiopathic hemolytic anemia and chronic disseminated intravascular coagulation (DIC) were thought to be complicated. The patient showed fragmentation hemolytic anemia and progressive diabetic microangiopathy, together with a mild elevation of serum fibrin(ogen) degradation products. Considering the state of chronic DIC, heparin therapy was started, but mild hemolysis persisted. It is possible that microangiopathic hemolytic anemia and chronic DIC cause a vicious cycle in patients with severe diabetic microangiopathy, leading to rapid progression of diabetic microangiopathy.


Severe Guillain-Barré syndrome in aged patients: the effect of plasmapheresis.

We report two aged patients with Guillain-Barré syndrome (GBS), in whom the rapid progression necessitated the use of a respirator. The first case, a 72-year-old woman, needed a respirator on the 5th day after onset of illness and the second case, a 74-year-old woman, needed a respirator on the 23rd day. We treated the first patient with plasmapheresis; the second patient underwent plasmapheresis as well as a large dose of intravenous methylprednisolone. Both patients showed remarkable recovery and did not need the respirator from the early stages. It was suggested that plasmapheresis is beneficial for treatment of aged patients with severe GBS, who necessitate the support of a respirator, because it prevents the decline in functional status by shortening the period of hospitalization.


Cytophagic histiocytic panniculitis with atypical lymphocytes in peripheral blood.

A 26-year-old female patient developed high fever, hepatosplenomegaly and subcutaneous nodules. Atypical lymphocytes were present in the peripheral blood. Skin biopsy revealed lobular panniculitis. Bone marrow examination showed prominent phagocytosis by benign histiocytes. The diagnosis of cytophagic histiocytic panniculitis was made, and the disease has been well controlled with oral prednisolone. This is the first report of cytophagic histiocytic panniculitis with atypical lymphocytes in the peripheral blood, which are frequently seen in virus-associated hemophagocytic syndrome. This observation suggests that underlying viral infection may be one factor in the development of cytophagic histiocytic panniculitis.


Ganglioneuroblastoma with disseminated bone marrow infiltration in an adult.

Ganglioneuroblastoma is an extremely rare neoplasm of adults. We present a case of adrenal ganglioneuroblastoma in a 47-year-old female with disseminated bone marrow involvement. Bone marrow involvement was the major manifestation which determined the mortality of this patient. This case suggests that the diagnosis of bone marrow involvement should be carefully considered even in adult-onset ganglioneuroblastoma.


Cushing's syndrome due to primary adrenocortical nodular dysplasia, cardiac myxomas, and spotty pigmentation, complicated by sarcoidosis.

A 23-year-old male patient revealed hypercortisolism with stigmata of Cushing's syndrome, and post-operative pathological examination demonstrated primary adrenal nodular dysplasia. Because of the presence of cardiac myxomas and skin pigmentation, the diagnosis of Carney's complex was given. After the control of hypercortisolism by adrenalectomy, the patient experienced iridocyclitis and bilateral hilar lymphadenopathy with elevated levels of serum angiotensin-converting enzyme and lysozyme, all of which indicated the presence of sarcoidosis. Despite the numerous recent descriptions concerning Carney's complex, an association with sarcoidosis has not yet been documented. Moreover, the sequential occurrence of sarcoidosis after adrenalectomy suggests an etiological link between these two rare disorders.


Freezing technique and quality of fresh-frozen plasma.

Cell-poor plasma was prepared by apheresis from 10 donors. From each donor, an amount of 200 ml was frozen rapidly to -40 degrees C in standard blood bags, and a further 200 ml was frozen slowly to -20 degrees C. Before freezing and after thawing, plasma samples were collected and frozen to -70 degrees C pending analysis. Coagulation factor VIII activity was reduced to 90% by rapid freezing and to 80% by slow freezing. Factor V was not influenced by rapid freezing, but slow freezing reduced the levels to 92% of the pre-freezing levels. In some of the plasma bags a slight increase in fibrinopeptide A occurred. However, soluble fibrin, thrombin-antithrombin complexes and spontaneous proteolytic activity were not altered by freezing. The beta-thromboglobulin increased slightly with slow freezing. Moreover, in a separate experiment, evaluating the possible effects of refreezing plasma samples, an increase in beta-thromboglobulin was also recorded, while the levels of factors VIII and V and von Willebrand factor were not affected. The changes in some variables, which were recorded in the cell-poor plasma, frozen soon after the blood donation at a slow freezing rate, must be regarded as insignificant in most clinical situations.


Bone marrow purging prior to autologous transplantation.

Our data suggest that ex vivo bone marrow purging using monoclonal antibodies (MoAbs) and sheep-anti-mouse immunobeads (SAM beads) prior to autologous bone marrow transplantation (ABMT) allows satisfactory tumor cell reduction without critical stem cell losses. Nevertheless, there is only a reduction but no elimination of tumor cells. The consequences will have to be clinically discussed.


Evaluation of a monocyte enrichment procedure using the blood cell separator Fresenius AS 104.

The small number of circulating monocytes in peripheral blood makes it difficult to collect enough cells for studies on the metabolism and analysis of receptor functions of this cell type for diagnostic aims and treatment. Therefore, a new procedure to enrich monocytes from peripheral blood using the cell separator Fresenius AS 104 was developed and evaluated. The separation is done using the tubing set 'P1Y-Gran-collect', which is a closed system with a single-stage separation chamber. The procedure is running continuously, while the cells are harvested cyclically. After processing of 4.9 l whole blood an average yield of (2.47 +/- 2.05) x 10(9) monocytes could be collected with an efficiency of 46 +/- 20%. The monocyte enrichment procedure using the Fresenius AS 104 provides a sufficient number of cells for the next steps: purification and concentration of the cells for drug monitoring, cell culturing, receptor analysis and further in vitro diagnostics.


Thrombotic thrombocytopenic purpura: a multimodality model of treatment including plasma exchange, i.v. immunoglobulin, prednisone, antiplatelet agents, vincristine and splenectomy.

Thirteen patients with thrombotic thrombocytopenic purpura were treated at our facility between 1985 and 1991. All patients were treated with plasma therapy (both plasma exchange and plasma infusions), prednisone, intravenous immunoglobulin, and antiplatelet agents. Twelve patients achieved remission (92.3%). One patient died from cerebral hemorrhage. Vincristine was administered to 5 patients who did not respond after the first two plasmaphereses. Splenectomy was performed in a patient who relapsed four times within a 2-year period. From the 12 patients achieving remission, 11 have been still in remission for a period of 3 to 69 months.


Pregnancy outcome of preterm premature rupture of the membranes before 28 weeks.

From January 1987 to December 1990 at Chang Gung Memorial Hospital, the fetal membrane ruptured in 47 singleton pregnancies at the 20th to the 28th gestational weeks. Sixty-six percent of the patients delivered within three days and 91.5% within one week. Only six (12.8%) patients carried their pregnancies over the 28th week. Of the 47 patients, 16 (34.0%) developed clinical evidence of chorioamnionitis during the latent period. The development of chorioamnionitis was not related to any of clinical factors [gestational age at rupture of the membranes, duration of rupture of the membranes before admission, positive endocervical culture, tocolysis, latent period or the presence of oligohydramnios (p > 0.05)]. The neonatal survival rate was 12.7% (six out of 47). Neonatal death was mainly attributable to prematurity. Gestational age beyond the 28th week and body weight greater than 1000 gm are two factors contributing to fetal survival. When fetal lung maturity has not occurred expectant management in the absence of infection is an alternative treatment.


Clinical analysis of surgical treatment for tuboovarian abscess.

The role of copious irrigation and drainage in the treatment of tuboovarian abscess (TOA) is crucial, especially for the patients who want to remain fertile. Some have used vaginal drainage via posterior colpotomy for patients with TOA, whereas others preferred irrigation using large-bore drains. In this study, we reported 31 cases of TOA. We found that for women who want to conceive again the best method of treatment is conservative surgery plus low pressure sump tube drainage.


A clinical evaluation of comprehensive dental treatment for children under general anesthesia.

The purpose of this study is to evaluate the comprehensive dental treatment for children under general anesthesia. From 1989 to 1991, 57 children with mean age of 3 years 2 months were treated, followed up with a minimal of 1 year. This procedure allows the dentition to be restored in one visit. Further care including preventive options and behavior shaping was provided on a 3-6 months recall schedule. The reasons for general anesthesia are that these children were either unable to accept treatment because of handicaps, extreme fear or young age. Their mean number of decayed tooth was 15 (Standard Deviation, SD = 5) and nearly three quarters of the children were under 6 years old. The most frequent treatment procedures were the extraction of teeth, composite resin restoration and Ni-Cr crown restoration. The Ni-Cr crown (1.7% failure rate) was more successful than the amalgam and composite resin restoration (9.7% failure rate). Pedo-strip crown had the highest failure rate (22%) for anterior teeth restoration. Nineteen children needed retreatment with conventional behavior guide. Six children had new caries and required further treatment. Thirty eight children returned for regular recall during the minimal 1 year follow-up period.


[Epidemiology of scrub typhus in Matsu Peikang Island].

A retrospective survey of the epidemiology of scrub typhus in 1990 in Matsu Peikang Island was made at the end of December of 1990. The diagnosis of scrub typhus was based on the presence of escar, typical clinical manifestation and good response to tetracycline treatment. There were 89 cases of scrub typhus studied, and except for one civilian, the other 88 cases were military personnel, occurring in 2.2% of the total military personnel on the island. However it occurred in 0.08% of the civilian population. Seasonal distribution of scrub typhus was limited to between June and October of 1990. The peak incidence occurred in July. Scrub typhus was distributed over the whole island. A higher incidence of scrub typhus occurred in soldiers and sergeants than in officers. A significant different incidence was found in different units. No fatalities were reported. Different units. No fatalities were reported. Different military activities, duties and the location of the military unit may affect the incidence of scrub typhus. The scrub typhus epidemic was also related to temperature.


[Clinical evaluation of gingival tissue restored with stainless steel crown].

The use of stainless steel crown for the restoration of primary molars is widely accepted in pediatric dentistry. There has been a concern regarding their effect on the health of the gingival tissue. It is a possibility that the preformed crown may be a contributing cause of gingivitis. This study evaluated one hundred and thirty-seven crowns in forty-five patients who had received pedodontic treatment at Chang Gung Memorial Hospital. The results indicated that the majority of stainless steel crowns had one or more defects, with crown crimping being the most common error. According to what the paired t-test showed, non-ideal crowns indicated that the gingival index was significantly higher than the entire mouth and control teeth. However the supragingival plaque accumulation of these teeth was significant lower than the entire mouth and control teeth. There was only a moderate positive correlation between supragingival plaque and gingivitis. The operator is necessary to adapt the stainless steel crown margin as closely as possible to the tooth and to avoid the mechanical defect of a crown. It minimizes the irritation of gingival tissue and diminishes the bacterial adherence of subgingival plaque, therefore preserving the health of gingival tissue.


[Implementation of stereotactic focal radiotherapy using 10 MV x-ray].

Stereotactic focal irradiation is also called stereotactic radiosurgery by some neurosurgeons. This irradiation is used for the treatment of brain AVM (arterio-venous malformation) and small tumor. Application of stereotactic focal irradiation was developed with CRW (Cosman-Roberts-Wells) stereotactic device and two dimensional (2D) computer treatment planning system using 10 MV x-ray from a linear accelerator. This process of irradiation includes: (a) Identification and localization of a target volume in CRW stereotactic frame by CT scan or angiography. (b) To verify the alignment, a linear accelerator was used as a simulator to take portal films in anterior and lateral views. This was done to ascertain the angles between arc therapy, to encompass the target volume, and to exclude the critical organs such as lens at 0 degrees, 45 degrees, 90 degrees and 315 degrees couch angles. (c) A 2D computer treatment planning system was used to generate an isodose curve distribution for each couch angle. Then this was used to calculate the monitor unit per degree for rotation treatment. (d) 10 MV x-ray was used to implement the stereotactic focal radiotherapy.


Trisomy 18 (Edwards syndrome): report of two cases.

Edwards syndrome is the second most common autosomal trisomy syndrome, resulting from an extra chromosome in chromosome 18. Recently we encountered two cases with the following representative features: intrauterine growth retardation, polyhydramnios, low-set ears, micrognathia and clenched hands. Both cases were female newborns and had an abnormal karyotype 47, XX, 18.


Subcapsular hematoma of spleen--a complication following extracorporeal shock wave lithotripsy for ureteral calculus.

Splenic trauma with hematoma following extracorporeal shock wave lithotripsy (ESWL) is very rare. We reported a case of subcapsular hematoma of spleen with impending rupture following ESWL for ureteral calculus. This case was noted to have liver cirrhosis and splenomegaly, and received a total of 2000 shock waves under 18 kilovoltage. The subcapsular hematoma occurred 2 months later. Splenectomy was undertaken for a symptomatic huge subcapsular hematoma and thrombocytopenia. We reviewed the literature and concluded that portal hypertension with severe coagulopathy are contraindications for ESWL, even in case with ureteral calculus.


[Low dose radioiodine treatment of papillary thyroid carcinoma in a child--a case report].

The thyroid carcinoma is rare in children and the optimal management is rather controversial. We report a case of a 7-year-old boy who had right neck masses and proved to be papillary thyroid carcinoma after near-total thyroidectomy. Post-operative 20 mCi radioiodine-131 (I-131) ablation scan, lung metastasis was suspected but the chest X ray was normal. After being lost to follow up for 4 years, the patient returned with the complaints of cough; the chest X ray was still normal. He then received 5 treatment with low dose (30 mCi) I-131 therapy and continued thyroxine replacement. Progressive decrease both of the thyroglobulin level and the intensity of radioactivity of lung were noted. After a total doses of 193 mCi I-131 therapy, neither pulmonary fibrosis nor bone marrow suppression was seen. Although the low dose (< or = 30 mCi) I-131 therapy was recommended, it was limited for the ablation therapy of the remnant thyroid tissue. Upon consideration of economics and the convenience of not being admitted to the isolation room, the low dose I-131 therapy seems feasible for children with thyroid carcinoma with systemic disease. However, the long term efficacy needs further evaluation.


[Cushing's syndrome with pregnancy. Report of three cases].

Cushing's syndrome with pregnancy is rare, and only about 60 cases have been reported. In the recent 4 years, 3 cases were diagnosed in Chang Gang Memorial Hospital. They presented with serious maternal complications early in the second month of pregnancy, including hypertension, proteinuria and lower leg edema. Unfortunately it was not diagnosed until the 20th week of pregnancy. They had the same hormone profile as other Cushing's syndrome patients who were not pregnant. Under the supportive treatment they had outcomes of two premature deliveries and one still birth. Just after delivery all patients received left adrenalectomy and pathology showed adenoma. All of them had good recovery courses. According to the literature, early treatment (surgical operation, medical treatment, or irradiation) could decrease maternal morbidity and fetal loss rate.


Ions, water, and energy in brain cells: a synopsis of interrelations.

A brief summary is given of some of the key points of the individual contributions at this International Brain Research Organization satellite meeting, presenting up-to-date, expert knowledge of energy metabolism, ionic turnover, and cell swelling at the cellular level of the mammalian central nervous system. On the basis of this material, we are also suggesting a unified concept of reciprocal interactions between metabolism, ion carriers, and ion channels, which are of crucial importance for the function of the central nervous system.


Changes in the glucose transporter of brain capillaries.

Brain capillary endothelium has a high density of the GLUT-1 facilitative glucose transporter protein. This is reasonable in view of the brain's high metabolic rate for glucose and its isolation behind unique capillaries with blood-brain barrier properties. Thus, the brain endothelium, which constitutes less than 0.1% of the brain weight, has to transport glucose for the much larger mass of surrounding neurons and glia. I describe here the changes that occur in the density of glucose transporters in brain capillaries of subjects with Alzheimer disease, where there is a decreased cerebral metabolic rate for glucose, and in a novel clinical entity characterized by defective glucose transport at the blood-brain barrier. In subjects with Alzheimer disease, cerebral microvessels showed a marked decrease in the density of the glucose transporter when compared with age-matched controls, but there was no change in the density of glucose transporters in erythrocyte membranes. Thus, I believe that the decreased density of glucose transporters in the brains of subjects with Alzheimer disease is the result rather than the cause of the disease. In contradistinction, the primary defect in glucose transport at the blood-brain barrier in subjects with the recently described entity is associated with decreased density of GLUT-1 in erythrocyte membranes.


Energy metabolism in developing brain cells.

During development different energy substrates are available to cells in brain in plentiful supply. The metabolic environment, which is dictated by the milk diet rich in fat, ensures that substrates in addition to glucose are available as fuels. Some substrates serve readily as primary fuels for respiration, whereas other substrates can serve other functions in addition to serving as primary fuels. Primary fuels for respiration serve to supply acetyl CoA directly and as a result always have first priority. With this criteria in mind, a consideration of substrate priority for respiration by developing brain is presented. Many studies in the decade, 1970-1980, in human infants and in the rat pup model show that both glucose and the ketone bodies, acetoacetate and D-(-)-3-hydroxybutyrate, are taken up by brain and used for energy production and as carbon sources for lipogenesis. Products of fat metabolism, free fatty acids, ketone bodies, and glycerol dominate metabolic pools in early development as a consequence of the milk diet. This recognition of a distinctive metabolic environment from the well-fed adult was taken into consideration within the last decade when methods became available to obtain and study each of the major cell populations, neurons, astrocytes, and oligodendrocytes in near homogeneous state in primary cultures. Studies on these cells made it possible to examine the distinctive metabolic properties and capabilities of each cell population to oxidize the metabolites that are available in development. Studies by many investigators on these cell populations show that all three can use glucose and the ketone bodies in respiration and for lipogenesis. Only one cell type, the astrocytes, can beta-oxidize fatty acids such as octanoate. By comparing the production of labeled carbon dioxide from glucose labeled on carbon-1 compared with carbon-6, it is clear that all three cell populations are capable of active hexose monophosphate shunt activity. Neurons and oligodendrocytes are capable of making good use of acetoacetate and D-(-)-3-hydroxybutyrate, whereas the best substrate for astrocytes is fatty acid. Under comparable conditions of incubation with astrocytes, fatty acids serve better than ketones, which in turn serve better than glucose in respiration. Some of the major factors that can explain the differing observations by different investigators on the capacity for substrate oxidation are presented. Over the last decade, astrocytes have captured the attention of neurobiologists because they have special attributes as metabolic support cells for the management of intermediary metabolism in brain.(ABSTRACT TRUNCATED AT 400 WORDS)


Oxidative metabolism in neuronal and non-neuronal mitochondria.

Methodological advances have allowed the isolation of two populations of synaptic (SM and SM2) and two populations of nonsynaptic (A and B) mitochondria from rat forebrain. All four populations of brain mitochondria are metabolically active and essentially free from nonmitochondrial contaminants. They (SM, SM2, A, and B) can oxidize a variety of substrates; the best substrate is pyruvate. With pyruvate as the substrate, the respiratory control ratios (i.e., state 3/state 4) in all four populations are routinely > 6. Results from numerous enzyme activity measurements provide strong support for the hypothesis that brain mitochondria are very heterogeneous with respect to their enzyme contents and that the enzymatic activities in a particular population of mitochondria, be they synaptic or nonsynaptic, differ from those in another population of mitochondria derived from either the same or another brain region. The major methodological advances in brain mitochondrial isolation greatly facilitate metabolic studies. For example, we have demonstrated that the K+ stimulation of brain mitochondrial pyruvate oxidation is mediated through a K(+)-induced elevation of the activation state of the pyruvate dehydrogenase complex and the K+ stimulation of the flux through the pyruvate dehydrogenase complex. Our previous and ongoing studies using primary cultures of hypothalamic neurons and astrocytes are consistent with the proposal that brain cells are heterogeneous with respect to their capabilities in energy metabolism. I can envisage that in the no-so-distant future, one could adapt these preparations of cells as the starting material for the isolation of mitochondria of known cellular origin for metabolic studies.


Physiologic coupling of glial glycogen metabolism to neuronal activity in brain.

Brain glycogen is localized almost exclusively to glia, where it undergoes continuous utilization and resynthesis. We have shown that glycogen utilization increases during tactile stimulation of the rat face and vibrissae. Conversely, decreased neuronal activity during hibernation and anesthesia is accompanied by a marked increase in brain glycogen content. These observations support a link between neuronal activity and glial glycogen metabolism. The energetics of glycogen metabolism suggest that glial glycogen is mobilized to meet increased metabolic demands of glia rather than to serve as a substrate for neuronal activity. An advantage to the use of glycogen may be the potentially faster generation of ATP from glycogen than from glucose. Alternatively, glycogen could be utilized if glucose supply is transiently insufficient during the onset of increased metabolic activity. Brain glycogen may have a dynamic role as a buffer between the abrupt increases in focal metabolic demands that occur during normal brain activity and the compensatory changes in focal cerebral blood flow or oxidative metabolism.


Energy metabolism at the cellular level of the CNS.

Evidence is accumulating that interactions between different cell types are of paramount importance for CNS function, for example, release of the excitatory transmitter glutamate from neurons and its preferential uptake into astrocytes. Some information is also available about energy metabolism in different cell types, or more often in models of different cell types (e.g., synaptosomes, cultured neurons, cultured astrocytes). In this review an attempt is made not only to correlate information obtained with different cell models but also to integrate this information with in vivo data, with histochemical observations, and with results obtained using brain slices. The emerging patterns indicate that neurons, synaptosomes, and astrocytes are all capable of complete glycolysis and oxidation of glucose. Elevated extracellular concentrations of potassium, known to occur in vivo, enhance energy metabolism by mechanisms that differ between neurons and astrocytes and to a large extent serve to reaccumulate extracellular potassium ions into adjacent cells. Monoaminergic agonists also stimulate energy metabolism, but mainly or exclusively in astrocytes. Profound differences are found between the effects of excess potassium and of aminergic transmitters, suggesting that high potassium concentrations enhance neuronal-astrocytic interactions, whereas the monoamines may tend to dissociate metabolic events in neurons and in astrocytes.


Energy requirements of CNS cells as related to their function and to their vulnerability to ischemia: a commentary based on studies on retina.

CNS tissue is well known to have large energy requirements. However, because of the difficulty of measuring rates of energy usage, relatively little is known about which cell types and which neurophysiological functions are the principal energy users. In experiments performed on rabbit retina in vitro, it was possible to measure O2 consumption and lactate production with the retinas under resting conditions and in different states of physiological activity. Resting energy consumption was large, as has been previously reported, and there were increases of up to 2.3 times with activity. Under some circumstances, the demands appeared to exceed the energy available. It was calculated that less than 5% of the energy generated by the retina was used for "vegetative metabolism" (i.e., for the anabolic reactions essential for viability), so that even in the resting state, the great majority of the energy usage appeared to be for function-related processes. This conclusion received further support from the finding that 50% of the energy generated was used for Na+ transport. The data obtained on retina are compared with published data on brain, which also suggest that a large fraction of the energy generated is used for function-related processes. It seems reasonable to conclude that by reversibly blocking the energy-demanding processes responsible for neurophysiological functioning, it would be possible to eliminate most of the energy requirements of CNS tissue and to reduce markedly its vulnerability to hypoperfusion.


Glycolytic and oxidative metabolic contributions to potassium ion transport in rat cerebral cortex.

Putative roles of glycolytic and oxidative metabolism in the removal of potassium ion from the extracellular space were examined in rat cerebral cortex. In response to direct electrical stimulation of the cerebral surface, the activity of extracellular potassium ion (Ko+) transiently increased. Inhibition of glycolysis with iodoacetate prolonged the time required for dissipation of the elevated Ko+. This slowing was most evident in the early period after stimulation, when Ko+ was relatively high. Levels of high-energy intermediates were unchanged by iodoacetate. In contrast, severe hypoxemia was without effect during the early phase of K+ removal but hypoxemia slowed the later restoration of the Ko+ baseline. These data demonstrate that the rapid removal of potassium ion from the extracellular space following intense neuronal activity is aided by the Embden-Myerhoff metabolic pathways and perhaps by direct coupling of ATP produced by glycolysis. We suggest that removal of potassium ion from the brain extracellular space depends on two ATP pools, one derived from oxidative phosphorylation, the other from glycolysis. The glycolytic ATP pool may be most involved in the early and rapid phase of potassium clearance; the oxidative ATP pool may be more associated with the second and slower phase of Ko+ clearance, and with the maintenance of the Ko+ baseline under 'resting' conditions.


Coupling of metabolism and electrical activity in cortical astrocytes.

Cortical mouse astrocytes in culture were impaled with two-channel microelectrodes. These mouse astrocytes have the same responses to different K+ concentrations, ouabain, and glutamate as cultured rat astrocytes, with the exception that a large barium-sensitive K+ conductance clamps the membrane potential at the K+ equilibrium potential. Glycolytic and mitochondrial inhibitors have little effect on the mouse astrocytes. Total blockade of energy metabolism leads to an irreversible, calcium-dependent depolarization, but only if applied for longer than 45 min. Increasing the extracellular K+ concentration to 60 mM increases the intracellular K+ concentration by 43 mM and the bicarbonate concentration by 22 mM and leads to a concomitant fast swelling. Together with the 20 mM increase in Cl- concentration reported in the literature this is a good indication for a Boyle- and Conway-mediated K(+)-anion influx with water. This influx is accomplished by the depolarization-induced opening of Cl- channels as reported in the literature. In conclusion, ischemia-like conditions have little direct, immediate impact on astrocytes. In contrast, ischemia-induced release of substances from neurones, such as K+, produces an immediate and fast response.