Calcium current modulation in frog sympathetic neurones: multiple neurotransmitters and G proteins.

1. Whole-cell calcium currents of bullfrog sympathetic neurones were partially inhibited by noradrenaline (NA), chicken-II-luteinizing hormone-releasing hormone (LHRH), muscarine, ATP, substance P, or intracellular dialysis with guanosine 5'-O-(3-thiotriphosphate)(GTP-gamma-S) or aluminium fluoride. These agents had similar effects on the activation kinetics of calcium current. 2. The amplitude of the LHRH effect varied from cell to cell. This did not correlate with cell size or the time of whole-cell dialysis. 3. The response to LHRH desensitized rapidly. Desensitization to LHRH did not affect inhibition by NA, ATP or substance P. 4. The effects of LHRH and NA were partially additive. 5. Cells dialysed with GTP-gamma-S still responded to NA or LHRH. However, NA or LHRH inhibited a smaller fraction of the calcium current than usual, and second applications of the same transmitter to GTP-gamma-S-dialysed cells were ineffective. 6. In GTP-gamma-S-dialysed cells, application of LHRH occluded the response to NA, but LHRH was still effective after application of NA. 7. The effect of GTP-gamma-S decreased during prolonged dialysis. 8. The effect of NA was selectively reduced by intracellular dialysis with the A-protomer of pertussis toxin (PTX), or extracellular pretreatment with high concentrations of whole PTX at room temperature. These treatments had little or no effect on the action of LHRH or ATP. 9. It is concluded that multiple G proteins can produce identical changes in calcium channel gating. The adrenergic receptor preferentially couples to a PTX-sensitive G protein.


The fit of fixed partial dentures joined by infrared soldering.

This study determined the accuracy of fit of three-unit fixed partial dentures joined by an infrared soldering technique compared with one-piece fixed partial denture castings and individually cast crowns. Wax patterns of prepared Ivorine teeth, maxillary left central incisor and maxillary left canine, were injection molded; a plastic rod was used as a pontic. One group of patterns was cast as one-piece dentures; the other group was sectioned in the connector area, cast individually and then joined by infrared soldering. Castings were seated on their respective dies, embedded in epoxy resin, and sectioned. Gap distances between the casting and the die were measured at specified marginal sites with a profile projector. Results showed that the fit of infrared-soldered fixed partial dentures was significantly better than that of one-piece castings and was comparable with the fit of single crowns. The gap openings measured in all castings were within the range of clinical acceptability.


Ophthalmic medications, glaucoma, and the surgical patient.

Patients receiving chronic ophthalmic therapy have a potential for respiratory or hemodynamic compromise during a surgical procedure requiring general anesthesia. During the perioperative phase of preoperative assessment and evaluation, pertinent patient information is gathered by asking the right questions and understanding the significance of the information gathered. The collected information, which is unique to these patients, is essential in facilitating in the intraoperative plan of care, thus insuring an uncomplicated, satisfactory, and safe immediate postoperative outcome.


A screening system for tardive dyskinesia: development and implementation.

1. Most diagnosed cases of tardive dyskinesia (TD) are mildly inconvenient to the patient, but some can be severe or life-threatening. The primary goal of intervention should be early identification of abnormal movements related to TD and the prescribing of an appropriate medication regimen. 2. Unless specific training occurs and a specific monitoring system is in place, TD movements may be missed. However, not all movements are necessarily related to TD. 3. Although screening and monitoring are valuable, nothing is more important than prevention. New medications must be developed that do not carry the risk of TD, and other approaches to treat TD must be developed.


Photoperiodic regulation of glutamatergic stimulation of secretion of luteinizing hormone in male Syrian hamsters.

It has been suggested that changes in endogenous glutamatergic stimulation of secretion of luteinizing hormone (LH) induced by photoperiod play a role in regulating seasonal cycles of reproductive activity. The aim of this study was to test the hypothesis that the glutamatergic control of the secretion of LH in the male Syrian hamster is sensitive to photoperiod, by determining whether the glutamate agonist N-methyl-D-aspartate (NMDA) could stimulate LH secretion in this species and, if so, to determine whether the response varied among animals exposed to different daylengths. In the first experiment, adult male hamsters were housed in either short day (8 h light: 16 h dark) for 6 weeks to induce testicular regression, or long days (16 h light: 8 h dark) to maintain testicular function, and the effects of systemic administration of NMDA on serum LH concentrations were determined. In the short-day hamsters, all s.c. doses of NMDA (25-75 mg kg-1 body weight) produced a robust rise in serum LH concentrations within 15 min. In the long-day hamsters, basal LH concentrations were higher than in short-day hamsters, but only the highest dose of NMDA produced a significant increase in LH concentrations, and the magnitude of this increment was less than those observed in short days. In hamsters in long days, the low doses of NMDA that did not significantly alter LH concentrations nevertheless significantly suppressed serum prolactin concentrations, demonstrating the efficacy of the drug. In hamsters in short days, serum prolactin concentrations were at the limit of detection of the assay, so no inhibitory effect of NMDA on prolactin secretion could be determined on this photoperiod. In the second experiment, the effects of a fixed dose of NMDA (50 mg kg-1 body weight) was tested at intervals in hamsters exposed to short days for a prolonged period such that their testes initially regressed, but then became scotorefractory and testicular recrudescence occurred. After 6 and 12 weeks in short days, NMDA stimulated LH secretion. However, after 24 weeks in short days when testicular recrudescence was complete, the response to NMDA was lost. A third experiment determined whether the reduced response to NMDA in hamsters on long days relative to those in short days might result from higher concentrations of circulating testosterone. Hamsters in long days were castrated to remove the influence of gonadal feedback, and the response to NMDA tested 3 weeks later when endogenous LH concentrations had risen to levels characteristic of the chronically castrated condition.(ABSTRACT TRUNCATED AT 400 WORDS)


No association between rheumatoid arthritis and insulin dependent diabetes mellitus: an epidemiologic and immunogenetic study.

To acquire more information on the controversial question of a possible association between rheumatoid arthritis (RA) and insulin dependent diabetes mellitus we searched for insulin dependent diabetes mellitus among patients hospitalized due to RA in 2 rheumatism hospitals in Finland. Nine subjects with insulin dependent diabetes mellitus were found among an annual number of 1460 patients admitted to one of the hospitals due to RA. These figures give a frequency of insulin dependent diabetes mellitus in patients with RA of 0.6% (95% confidence interval 0.2-1.0%), which does not exceed the prevalence of insulin dependent diabetes mellitus among the middle aged population of Finland in general (0.5-0.6%). Accordingly, no overrepresentation of homozygosity for HLA-DR4 was found among the total number of 25 patients with RA as well as insulin dependent diabetes mellitus, though the opposite might be expected as these diseases have a common DR4 association--RA with DR4 and DR1 and insulin dependent diabetes mellitus with DR4 and DR3. Instead, an increased frequency of DR1 (p less than 0.0002) and the antigen combination DR1/4 (p less than 0.01) was found in the subjects with both RA and insulin dependent diabetes mellitus compared with the subjects with insulin dependent diabetes mellitus alone.


Isolated polyarteritis nodosa of the male reproductive system.

Polyarteritis nodosa (PAN) frequently affects the testis and epididymis. We describe a 29-year-old man with isolated PAN of the testis and review reported cases of isolated PAN of the testis or epididymis. Our patient underwent orchiectomy and at followup 17 months later was without evidence of recurrence or development of systemic PAN.


Necrotizing mesenteric vasculitis after longstanding cutaneous polyarteritis nodosa.

We describe a 21-year-old woman with cutaneous polyarteritis nodosa (PAN) who developed necrotizing mesenteric vasculitis 6 years after the onset of skin disease. Repeated investigation during that 6-year interval failed to reveal any evidence of systemic PAN. We were unable to wean the patient from prednisone or completely control her skin disease with topical and systemic therapy, including supersaturated potassium iodide, dapsone, azathioprine, methotrexate or plasmapheresis before the development of the mesenteric vasculitis, which responded to cyclophosphamide and prednisone. Development of visceral vasculitis after long-standing cutaneous PAN has very rarely been reported.


Carboxamide group conformation in the nicotinamide and thiazole-4-carboxamide rings: implications for enzyme binding.

Ab initio computations (RHF/6-31G* parallel 3-21G*) were performed on the thiazole-4-carboxamide group found in the antitumor drug tiazofurin and its dehydrogenase-binding anabolite thiazole-4-carboxamide adenine dinucleotide (TAD). Results indicate that the carboxamide group is constrained in the conformation in which the amino group is cis-planar to the ring nitrogen. This finding is consistent with carboxamide conformations observed in crystal structures of the thiazole nucleosides. In contrast, ab initio computations on the nicotinamide and dihydronicotinamide rings found in the cofactors NAD+ and NADH indicate two stable conformations for the carboxamide group. This finding confirms previous computational studies and is consistent with results from a survey of the Cambridge Structural Database. Natural bond orbital analysis indicates that the low-energy carboxamide conformers of all three heterocycles are stabilized by a combination of electrostatic and charge transfer interactions. A survey of the Protein Data Bank indicates that the carboxamide group conformation in TAD is constrained to that favored by dehydrogenase-bound NAD(P)(H).


Diel sugar-feeding and host-seeking rhythms in mosquitoes (Diptera: Culicidae) under laboratory conditions.

Mosquito sugar-feeding and host-seeking rhythms were recorded in the laboratory using remote sensors. In all five species studied, the two rhythms were nearly synchronous. In Anopheles quadrimaculatus Say, Culex quinquefasciatus Say, and Aedes triseriatus (Say), host-seeking activity increased slightly earlier than sugar feeding in the evening. The evening sugar-feeding period was longer than the evening host-seeking period in Aedes aegypti (L.), but the two periods were of similar duration in Aedes albopictus (Skuse). In the morning, the only clear difference between the two behaviors occurred in Cx. quinquefasciatus, which had a host-seeking peak but lacked a sugar-feeding peak. When exposed concurrently to both host and sugar stimuli, sugar feeding practically ceased in Ae. albopictus and Ae. aegypti. In the presence of host stimuli, the sugar-feeding rhythms of An. quadrimaculatus, Cx. quinquefasciatus, and Ae. triseriatus differed from those obtained in the absence of host stimuli by having an earlier onset of evening activity, a relatively smaller evening activity peak, and a more irregular activity pattern during early scotophase, respectively. We concluded that inseminated, nulliparous females have nonspecific appetitive feeding periods, and that the order in which sugar and blood are sought largely may be a function of factors other than differences in diel rhythms.


Virus-dependent mortality in Rift Valley fever, eastern equine encephalomyelitis, and chikungunya virus-inoculated mosquito (Diptera: Culicidae) larvae.

The effect of inoculation of mosquito larvae with Rift Valley fever (RVF) virus on survival to the adult stage was evaluated in Aedes aegypti (L.), Ae. fowleri (Charmoy), Ae. mcintoshi Huang, Ae. taeniorhynchus (Wiedemann), Ae. triseriatus (Say), Eretmapodites quinquevittatus Theobald, Anopheles albimanus Wiedemann, and Culex pipiens L. Pupation rates were similar for RVF virus-inoculated and diluent-inoculated larvae of all mosquito species tested except Cx. pipiens. However, with the exception of An. albimanus and Ae. triseriatus, virtually all pupae derived from RVF virus-inoculated larvae failed to emerge successfully as adults. In contrast, both pupation and emergence rates were similar for diluent-inoculated and either La Crosse or St. Louis encephalitis virus-inoculated larvae of Ae. taeniorhynchus. There was also poor survival to the adult stage of Ae. taeniorhynchus inoculated with either eastern equine encephalomyelitis (EEE) or chikungunya (CHIK) virus. The high mortality rates observed under laboratory conditions of pupae derived from larvae inoculated with either RVF, EEE, or CHIK virus may be responsible for the lack of laboratory confirmation of vertical transmission of these viruses.


Phenotype-genotype correlations in X linked retinitis pigmentosa.

Retinitis pigmentosa (RP) represents a group of clinically heterogeneous retinal degenerations in which all modes of inheritance have been described. We have previously found two different clinical profiles in X linked RP as a function of age and mode of onset. The first clinical form has very early onset with severe myopia. The second form starts later with night blindness with mild myopia or none. At least two genes have been identified in X linked forms, namely RP2 (linked to DXS7, DXS255, and DXS14) and RP3 (linked to DXS84 and OTC) on the short arm of the X chromosome. In order to contribute to phenotype-genotype correlations in X linked RP, we tested the hypothesis that the two clinical profiles could be accounted for by the two different gene loci. The present study provides evidence for linkage of the clinical form with early myopia as the onset symptom with the RP2 gene (pairwise linkage to DXS255: Z = 3.13 at theta = 0), while the clinical form with later night blindness as the onset symptom is linked to the RP3 gene (pairwise linkage to OTC: Z = 4.16 at theta = 0).


Non-specific X linked mental retardation with aphasia exhibiting genetic linkage to chromosomal region Xp11.

A new type of non-specific X linked mental retardation is described in a three generation family. The three affected males had severe mental retardation (IQ 20 to 30), mutism, growth failure, frequent infections, seizures, and the following minor anomalies: brachycephaly, frontal hair whorl, square face, large mouth, thick lips, and prognathism. There was not a characteristic facies. Normal laboratory studies on the proband included a karyotype with fragile X screening, skeletal survey, blood amino acid, urine organic acid, and HGPRT levels. Linkage analysis was performed with 10 X chromosome DNA probes of which probe DXS255 at chromosomal region Xp11.22 gave a maximal two point lod score of 2.10 if phase was inferred and 1.20 if it was not. Crossovers were shown with probes mapping to regions Xp22, Xp21, and Xq28. Comparison of these patients with 80 X linked causes of mental retardation, including 41 which might be classified as 'non-specific', showed no other disorders compatible with the phenotypic and linkage data.


Mutation analysis of 184 cystic fibrosis families in Wales.

We describe a molecular analysis of 184 cystic fibrosis (CF) families in Wales. To determine accurate frequency data for the CF mutations in the Welsh population, families with at least three Welsh grandparents were strictly regarded as Welsh. Of these 74 families, we have identified approximately 90% of mutations causing CF, with delta F508 accounting for 71.8% and 621 + 1G greater than T 6.7%. We observed a significant difference between the Welsh and Scottish frequencies of 621 + 1G greater than T. To allow the rapid and efficient screening for the more common mutations we modified a multiplex used by Watson et al enabling the detection of delta F508, G551D, and R553X simultaneously with 621 + 1G greater than T. In parallel to this system we ran the Cellmark Diagnostics ARMS multiplex kit, which detects delta F508, 621 + 1G greater than T, G551D, and G542X. RFLP analysis of the 184 families shows that the delta F508 chromosomes are almost exclusively found on the B haplotype (XV2c 1, KM19 2); the other CF mutations have more heterogeneous backgrounds. Strong haplotype correlations exist between the markers XV2c, KM19, D9, and G2 and the other CF mutations. Haplotype data suggest that there are at least seven mutations that remain to be identified in these families.


Quantitative analysis of depolarization-induced ATP release from mouse brain synaptosomes: external calcium dependent and independent processes.

We and others have shown previously that ATP is secreted from mouse brain synaptosomes following depolarization of the membrane by high [K+]o and the time course can be monitored accurately by measuring the light emitted from luciferin-luciferase included in the reaction medium. In the present work we have evaluated the relative importance of [Ca2+]o and membrane potential on the ATP secretion process by modelling the time course of ATP release under different conditions. After correction of the records for destruction of released ATP by synaptosomal ecto-ATPase activity, we found that ATP secretion occurs by an apparent first order process. We also established that, in addition to the classical [Ca2+]o-dependent mode, ATP secretion also occurred in the absence of extracellular calcium ([Ca2+]o less than 1 microM). Upon lowering the extracellular Ca2+ concentration, both the rate and the extent of ATP secretion decreased. To assess the contribution of membrane potential to the release rate we measured ATP secretion at membrane potentials determined by extracellular [K+]o (or [Rb+]o) as defined by the distribution of the carbocyanine dye, diSC3(5). Rate constants computed from measured secretion curves revealed that this parameter was essentially independent of membrane potential in the absence of [Ca2+]o. Noise analysis of the light signal showed that the variance increased upon stimulation by high [K+]o, suggesting that both modes of secretion are quantal. Thus, we conclude that the rate of ATP secretion from nerve terminals depends upon Ca2+ entry but not on membrane potential, per se.


Beta 1- and beta 2-adrenoceptors in sheep cardiac ventricular muscle.

The presence of beta 2-adrenoceptors in the sheep ventricular myocardium was assessed by the radioligand binding technique and functional studies. In membrane preparations, the competition curve between [3H]-dihydroalprenolol and the selective beta 1-antagonist CGP 20712A (0.1 nM-1 mM) was clearly biphasic, and revealed the presence of two different binding sites showing an affinity (pKD) for CGP 20712A of 9.5 +/- 0.9 and 4.5 +/- 0.4, respectively. The relative proportion of beta 1:beta 2 adrenoceptors was about 70:30 in both the right and left ventricle. In ventricular trabeculae driven at 1Hz, isoprenaline (1-300 nM) caused a dose-dependent increase in the force of contraction, the maximum effect being 298 +/- 26 mg, associated with reduction of time to peak tension (t1, clinotropic effect) and relaxation time (t2, 298 +/- 26 mg, associated with reduction of time to peak tension (t1, clinotropic effect) and relaxation time (t2, lusitropic effect). The inotropic dose-response curve for isoprenaline was significantly shifted to the right by pretreatment of the preparations with 0.1 microM CGP 20712A or with the selective beta 2-antagonist ICI 118551 (50 nM). In the presence of CGP 20712A (0.1 microM), isoprenaline, up to a concentration of 10 microM, did not affect either t1 or t2; on the other hand, pretreatment of the preparations with ICI 118551 (50 nM) fully antagonized the clinotropic but not the lusitropic effect of isoprenaline. In the presence of CGP 20712A procaterol (0.01-10 microM), a beta 2-adrenoceptor agonist, induced a positive intropic effect which was not associated with any significant modifications in t1 or t2. This effect was completely abolished by ICI 118551 (50 nM). The positive inotropic action of isoprenaline (1 microM) was associated with a significant decrease in action potential duration measured at -60 mV (220 +/- 8 and 193 +/- 10 ms in the absence and presence of isoprenaline, respectively; P less than 0.05). In the presence of CGP 20712A (0.1 microM) alone, isoprenaline (1 microM) still induced a significant increase in contractility but the action potential profile was only slightly affected. The effects of isoprenaline were fully antagonized by the simultaneous presence of CGP 20712A and ICI 118551 (10 nM). It is concluded that both beta 1- and beta 2-adrenoceptors appear to coexist in sheep ventricular myocardium where their stimulation mediates a positive inotropic effect. However, their functional role on the relaxation phase of the twitch may be different.


Coexistence of cholinergic, catecholaminergic, serotonergic, and glutamatergic neurotransmitter markers in mouse clonal hybrid neurons derived from the septal region.

Two clonal immortalized neurons designated SN6.1b and SN6.2a were isolated by limiting dilution from a mouse embryonic septal cholinergic neuronal hybrid cell line SN6 (Hammond et al., 1986). In the serum-containing medium without extra differentiating agents, one-third of SN6.1b cells stably exhibited a morphology of differentiated neurons with extensive elaborate neurites, while a majority of SN6.2a cells, along with the parent cell line SN6, were round in shape with poorly branched short processes. Neurochemical studies showed that both clones synthesized choline acetyltransferase (ChAT), dopamine, norepinephrine, serotonin, and glutamate. Immunocytochemically, they expressed a number of neuronal antigens, such as 200-kDa neurofilament protein, neuron-specific enolase, microtubule-associated protein 2, tau protein, tubulin, neural cell adhesion molecule, Thy-1.2, saxitoxin-binding sodium channel protein, ChAT, tyrosine hydroxylase, serotonin, and glutamate. The coexistence of cholinergic, catecholaminergic, serotonergic, and glutamatergic neurotransmitter markers in the clonal hybrid septal neurons that express a variety of immunocytochemical properties of differentiated neurons suggests that embryonic septal cholinergic neurons are potentially multiphenotypic with respect to neurotransmitter synthesis.


Cyclic AMP, but not basic FGF, increases the in vitro survival of mesencephalic dopaminergic neurons and protects them from MPP(+)-induced degeneration.

We studied how stimulation of protein kinase C and cAMP-dependent protein kinases affect the development of mesencephalic dopaminergic neurons in primary cell cultures derived from fetal rats at embryonic day E14. The effects of compounds which activate these second messenger systems were compared to those of basic fibroblast growth factor (bFGF) and insulin-like growth factor I (IGF-I). In mesencephalic cultures, there was a continuous loss of dopaminergic neurons. Despite this decline in cell number, neurotransmitter uptake per neuron increased with time, indicating that the surviving dopaminergic neurons continued their biochemical differentiation while others degenerated. IGF-I and bFGF did not affect the number of dopaminergic neurons. However, dopamine uptake per neuron was significantly higher in bFGF and IGF-I treated cultures, suggesting that these factors stimulated differentiation. Protein kinase C and cAMP-dependent protein kinases were not involved in mediating the effects of bFGF and IGF-I. Treatment of cultures with phorbol esters did not affect dopamine uptake, whereas elevated levels of intracellular cAMP resulted in an increase in dopamine uptake which was additive to that elicited by bFGF or IGF-I. Further analysis revealed that exposure of mesencephalic cultures to dibutyryl cAMP (dbcAMP) during the first 3 days after plating increased the survival of dopaminergic neurons, whereas prolonged treatment attenuated the development of the dopamine uptake system. Moreover, cyclic AMP, but not bFGF, was able to prevent the degeneration of dopaminergic neurons induced by 1-methyl-4-phenyl-pyridinium ion (MPP+), the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The results suggest that increased intracellular levels of cAMP protect dopaminergic neurons in situations of stress like the process of dissociation and plating or the exposure to neurotoxic compounds. Our results reveal novel possibilities for the treatment of Parkinson's disease.


Characteristics of large neutral amino acid-induced release of preloaded L-glutamine from rat cerebral capillaries in vitro: effects of ammonia, hepatic encephalopathy, and gamma-glutamyl transpeptidase inhibitors.

The release of newly loaded L-[14C]glutamine (L-Gln) from rat cerebral cortical capillaries was stimulated by L-transport system substrates: tryptophan (TRY), leucine (leu), and nonlabeled L-Gln, respectively, by 32, 50, and 40% above the basal release resulting from superfusion with standard Krebs-Henseliet buffer. However, no stimulation was observed upon treatment with D-Gln or L-glutamate (L-Glu), which are not the L-system substrates, or with ammonium chloride. The stimulatory effect of TRY was temperature dependent but sodium independent, and was abolished in the presence of a sulfhydryl reagent N-ethylmaleimide (NEM). The results support the view that the L-Gln-stimulated uptake of large neutral amino acids (LNAA) across the blood-brain barrier involves the L-system mediated Gln-LNAA exchange. The TRY-stimulated Gln release was enhanced in vitro by simultaneous addition of ammonium chloride, and in capillaries derived from rats with acute hepatic encephalopathy (HE). These results confirm the role of Gln-LNAA exchange in the excessive accumulation of LNAA in brain observed in a variety of hyperammonemic conditions. Superfusion of L-Gln-loaded capillaries in a buffer containing gamma-glutamyl transpeptidase (GGT) inhibitors, serine borate (SB) or 6-diazo-5-oxo-L-norleucine (DON), increased the basal L-Gln release and made it irresponsive to subsequent treatment with TRY. However, the basal release was also increased by superfusion with serine alone or Leu, and this treatment abolished the subsequent effect of TRY as well. Moreover, DON stimulated L-Gln release from capillaries superfused in a standard way, and the effects of DON and TRY were additive. Hence, in the present conditions, SB and DON acted as L-system substrates rather than as GGT inhibitors. Taken together, the results do not support the concept that GGT mediates the Gln-LNAA exchange.


Further evidence for the dynamic formation of transmitter quanta at the neuromuscular junction.

Fatt and Katz (Nature 166:597-598, 1950; J Physiol 117:109-128, 1952) attributed miniature endplate potentials (MEPPs) to the action of a standard quantity of transmitter, the quantum (Del Castillo and Katz, J Physiol 124:560-573, 1954). Quantal packets of transmitter were proposed to be preformed (Del Castillo and Katz, In CNRS Paris (Ed): "Microphysiologie comparée des éléments excitables" 67:245-258, 1957) and stored in large numbers in the motor nerve terminal. Statistical analyses of intervals between MEPPs and numbers of quanta composing small endplate potentials indicated that quantal release was a random process and that release sites functioned independently of each other. With the discovery of synaptic vesicles it was proposed that each contained one quantum of transmitter. The quantal-vesicular hypothesis (Del Castillo and Katz, as cited above) fails, however, to explain amplitude distributions of MEPPs that are skewed and/or that show multiple peaks (Kriebel et al., Brain Res Review 15:167-178, 1990). The drop formation process (Shaw, "The Dripping Faucet as a Model Chaotic System," Santa Cruz, CA: Aerial Press, Inc., 1984) was shown to generate amplitude classes of drops that were similar to classes of MEPPs which suggested that rapid changes in quantal size and ratios of skew- to bell-MEPPs could be explained with a simple dynamic process which determines quantal size at the moment of release (Kriebel et al., as cited above, 1990). Further similarities between miniature endplate currents (MEPCs) and the formation of drops are reported here. We found that rapid changes in MEPC amplitudes and time courses, which accompany an increase in frequency, mimic changes in drop sizes that accompany increases in flow rate. MEPC intervals have a minimum and their distributions are comparable to those of drop intervals. During an increased rate of transmitter release, MEPP amplitudes and intervals were positively correlated. The results suggest that spontaneously released transmitter "packets" are formed at the moment of release and that transmitter supply to the process that forms packets is continuous.


Role of vif in replication of human immunodeficiency virus type 1 in CD4+ T lymphocytes.

The viral infectivity factor gene vif of human immunodeficiency virus type 1 has been shown to affect the infectivity but not the production of virus particles. In this study, the effect of vif in the context of the HXB2 virus on virus replication in several CD4+ T-cell lines was investigated. vif was found to be required for replication in the CD4+ T-cell lines CEM and H9 as well as in peripheral blood T lymphocytes. vif was not required for replication in the SupT1, C8166, and Jurkat T-cell lines. The infectivity of vif-defective viruses depended on the cell type in which the virus was produced. In CEM cells, vif was required for production of virus capable of initiating infection in all cell lines studied. vif-defective virus produced by SupT1, C8166, and Jurkat cells and the monkey cell line COS-1 could initiate infection in multiple cell lines, including CEM and H9. These results suggest that vif can compensate for cellular factors required for production of infectious virus particles that are present in some cell lines such as SupT1, C8166, and Jurkat but are absent in others such as CEM and H9 as well as peripheral blood T lymphocytes. The effect of vif was not altered by deletion of the carboxyl terminus of gp41, a proposed target for vif (B. Guy, M. Geist, K. Dott, D. Spehner, M.-P. Kieny, and J.-P. Lecocq, J. Virol. 65:1325-1331, 1991). These studies demonstrate that vif enhances viral infectivity during virus production and also suggest that vif is likely to be important for natural infections.


Truncation of the human immunodeficiency virus type 1 transmembrane glycoprotein cytoplasmic domain blocks virus infectivity.

Human immunodeficiency virus type 1 contains a transmembrane glycoprotein with an unusually long cytoplasmic domain. To determine the role of this domain in virus replication, a series of single nucleotide changes that result in the insertion of premature termination codons throughout the cytoplasmic domain has been constructed. These mutations delete from 6 to 192 amino acids from the carboxy terminus of gp41 and do not affect the amino acid sequence of the regulatory proteins encoded by rev and tat. The effects of these mutations on glycoprotein biosynthesis and function as well as on virus infectivity have been examined in the context of a glycoprotein expression vector and the viral genome. All of the mutant glycoproteins were synthesized, processed, and transported to the cell surface in a manner similar to that of the wild-type glycoprotein. With the exception of mutants that remove the membrane anchor domain, all of the mutant glycoproteins retained the ability to cause fusion of CD4-bearing cells. However, deletion of more than 19 amino acids from the C terminus of gp41 blocked the ability of mutant virions to infect cells. This defect in virus infectivity appeared to be due at least in part to a failure of the virus to efficiently incorporate the truncated glycoprotein. Similar data were obtained for mutations in two different env genes and two different target cell lines. These results indicate that the cytoplasmic domain of gp41 plays a critical role during virus assembly and entry in the life cycle of human immunodeficiency virus type 1.


The human immunodeficiency virus (HIV) gag gene product p18 is responsible for enhanced fusogenicity and host range tropism of the highly cytopathic HIV-1-NDK strain.

Formation of large syncytia and rapid cell killing are characteristics of the Zairian human immunodeficiency virus type 1 isolate HIV-1-NDK, which is highly cytopathic for CD4+ lymphocytes in comparison with the HIV-1-LAV prototype. Chimeric viruses containing different combinations of HIV-1-NDK genetic determinants corresponding to the splice donor, the packaging signal, and the coding sequence of the p18gag protein together with the HIV-1-NDK EcoRI5278-XhoI8401 fragment were obtained by polymerase chain reaction-directed recombination. Phenotypic analysis of recombinant viruses indicated that 75 amino acids from the N-terminal part of HIV-1-NDK p18gag protein together with the HIV-1-NDK envelope glycoprotein are responsible for enhanced fusogenicity of HIV-1-NDK in CD4+ lymphocytes as well as for enhanced infectivity of HIV-1-NDK in some CD4- cells lines. The HIV-1-NDK splice donor/packaging sequence and the sequence encoding the gag protein p25 were not important for the variation observed in HIV-1 fusogenicity.


Recognition efficiency of the hepatitis B virus polyadenylation signals is tissue specific in transgenic mice.

The hepatitis B virus genome contains a unique polyadenylation (TATAAA) signal which is differentially utilized in the formation of the various hepatitis B virus transcripts. A head-to-tail multiple-copy insertion of a viral fragment comprising the viral enhancer, the X promoter, the X open reading frame, and the viral poly(A) signal in transgenic mice allowed us to monitor tissue-specific differences in the expression of transcripts initiating from the X promoter. These transcripts are efficiently processed at the first polyadenylation site in the liver, while in the kidney, the brain, and the testis, a portion of the transcripts covers two copies of the transgene, since only the second polyadenylation site is properly recognized. As discussed in this article, this observation suggests a tissue-specific distribution of cellular factors involved in polyadenylation.


Two-stage Fowler-Stephens orchiopexy in the management of intra-abdominal testes.

Of 22 boys with an intra-abdominal testis 8 (12 testes) underwent the 2-stage Fowler-Stephens orchiopexy. During stage 1 the testicular artery and internal spermatic vein were ligated in situ 2 to 3 cm. superior to the intra-abdominal testis. The testicular vessels were transected inferior to the ligatures 6 months later and the testis was brought to the scrotum with the standard Fowler-Stephens orchiopexy technique. Patient age ranged from 1 to 6 years (mean 3.2 years). At followup 11 of 12 testes (92%) are in the scrotum and have a normal consistency and size, while 1 (8%) is atrophic. In this preliminary series the 2-stage Fowler-Stephens orchiopexy has a success rate equal or possibly superior to the standard Fowler-Stephens orchiopexy. Whether ultimate testicular function is improved, however, remains to be determined.


Laparoscopic orchiectomy for unilateral intra-abdominal testis.

We present 2 cases of laparoscopic removal of a unilateral intra-abdominal testis. Removal of a unilateral intra-abdominal testis is indicated in patients more than 10 years old because the malignant potential of an intra-abdominal testis outweighs any cosmetic benefit of orchiopexy. Laparoscopic orchiectomy is a safe and effective surgical procedure for adolescents and adults with this disease entity providing outpatient therapy and prompt rehabilitation.


Expression of SSEA-1 carbohydrate antigen correlates with stage, grade and metastatic potential of transitional cell carcinoma of the bladder.

Expression of stage-specific embryonic antigen-1 (SSEA-1) was immunohistochemically analyzed in primary cancerous regions from transitional cell carcinoma of the bladder. Lymph node metastasis occurred in 14 (50%) of 28 patients with high expression of SSEA-1 antigen, but in only one (4%) of 23 patients with low or no expression. Of 36 invasive bladder carcinoma patients with no metastasis at operation, 8 (57%) of 14 with high expression of SSEA-1 antigen died of cancer or had metastasis, whereas 4 (18%) of 22 with low or no expression had progression of the disease. In addition, stage pT3b-4 tumors more frequently reacted with SSEA-1 MAb than stage pT1 tumors (p less than 0.01). Grade 2 or 3 tumors were also more reactive than grade 1 tumors, which were all unreactive except for one (p less than 0.01, respectively). Our data suggest that SSEA-1, which is a Le(x) antigen, correlates with stage and grade as well as metastatic phenotype of transitional cell carcinoma of the bladder.


Effect of alpha 1-adrenoceptor blockade on the left ventricular force-length relationship in dogs.

We used the left ventricular (LV) end-systolic force-diameter (Fes-Des) relation to evaluate the effect of an alpha1-adrenoceptor antagonist (bunazosin hydrochloride) on the contractility of the beta-blocked left ventricle. Nine adult mongrel dogs were instrumented with ultrasonic crystals to measure LV diameter and a micromanometer to measure LV pressure. Beta-adrenergic and vagal blockade was induced with intravenous propranolol (2 mg/kg) and atropine (0.2 mg/kg), respectively, and preload was decreased by inferior vena caval occlusion. The slope (Ec) and extrapolated diameter intercept (Do) of the LV Fes-Des relation were derived from end-systolic data obtained in the control state (after beta-blockade) and after bunazosin infusion (1 mg/kg). Ec was used as a new index of LV contractility. After bunazosin infusion, the heart rate and Ec were decreased by 7 and 22%, respectively, in comparison with the control state, whereas Do did not change. These results indicate that alpha1-adrenoceptor blockade significantly reduces myocardial contractility in the beta-blocked canine heart, perhaps by decreasing the intracellular calcium concentration and/or myosin ATPase activity.


[Glutamic acid as an excitatory neurotransmitter].

The role of L-glutamic acid (Glu) as an excitatory neurotransmitter is reviewed. The idea that Glu is a main excitatory transmitter in the central nervous system (CNS) is now well supported by several lines of evidence, including its excitatory action, presence in the CNS, release, uptake mechanisms and suppression of synaptic transmission by its antagonists. Receptors for Glu are classified into ionotropic and metabotropic receptors. The former is further classified into non-NMDA and NMDA subgroups. The non-NMDA receptor mediates signal transduction between central neurons. Activation of the NMDA receptor causes an increase in intracellular calcium concentration in the postsynaptic neuron and thereby induces plastic changes such as, memory and learning. The function of the metabotropic receptor is yet to be elucidated.


[DNA diagnosis for inherited metabolic disorders].

Progress in molecular genetics has made it possible to detect the structure of cDNA and genomic DNA of enzyme and protein, as well as the mutation in DNA level. It also provides a vast amount of new information for diagnosis and treatment, and it can actually be used in prenatal diagnosis and carrier screening. There is great hope that patients with genetic disorders can be treated by somatic gene replacement. We introduced here the methods for detection of unknown mutations of inherited metabolic disorders, and screening patients for characterized mutations, and the expression analysis of mutant cDNA, as an example of phenylketonuria.


[The metabolic basis of the hyperphenylalaninemias and tyrosinemia].

The hyperphenylalaninemias are caused by the defect of either phenylalanine hydroxylase (PAH) or tetrahydrobiopterin (BH4) cofactor. The former is diagnosed as phenylketonuria (PKU) or benign hyperphenylalaninemia, based on the serum phenylalanine values. The latter, so called malignant hyperphenylalaninemia, includes three enzyme defects, dihydropteridine reductase (DHPR), 6-pyruvoyl tetrahydropterin synthase (PT PS) and guanosine triphosphate cyclohydrolase (GTP-CH). Excess phenylalanine and its metabolites cause brain damage before 6 years of age. Deficiency of BH4 impairs two other hydroxylases (tyrosine and tryptophan), and severe neurological symptoms develop because of the lack of neurotransmitters. Tyrosinemia I, II, and III are different enzyme defects, fumarylacetoacetate hydrolyase (FAH), hepatic tyrosine aminotransferase (TAT), and 4-hydroxyphenylpyruvate acid oxidase, respectively. Tyrosinemia I is associated with severe involvement of the liver, kidney and central nervous system. Tyrosinemia II has mental retardation, palmar hyperkeratosis and corneal ulcers. Tyrosinemia III has mild mental retardation but no eye or skin manifestations.


[Metabolic abnormalities of amino acids in patients with alcoholic liver damage].

The metabolic abnormality of amino acids in patients with alcoholic liver damage is discussed. The abnormalities are variable according to the degree of hepatic damage, the amount of alcohol consumption, and the intake of amino acids. In general, the plasma concentration of branched-chain amino acids, aromatic amino acids and alpha-amino-n-butyric acid increases, whereas that of hydroxy amino acids, alanine and proline decreases, in alcoholics with liver damage. Serum gamma-glutamyltranspeptidase activity increases with the increase of alcohol consumption. This increase is accentuated by lowered carbohydrate intake at the time of alcohol ingestion. A nutritional survey among healthy male subjects revealed that the intake of cereals decreases with increasing amount of alcohol consumption, a finding which suggests that the intake of some amino acids may be altered by drinking habit.


[Amino acid metabolism in neurodegenerative diseases].

Although various neurological diseases occur in patients with inborn error of metabolism of amino acids, amino acids also act as neurotransmitters. Glutamic acid, aspartic acid and glycine play roles as an excitatory neurotransmitter, but exert a neurodegenerative effect in case of the excessive release. Extensive studies have recently been performed on glutamate receptors, especially N-methyl-D-aspartate (NMDA) receptor in the hippocampus. Alzheimer brain shows a decreased number of NMDA receptors in the frontal cortex. The parkinsonian changes caused by MPTP is abolished by the administration of a NMDA antagonist. gamma-Aminobutyric acid (GABA) acts as an inhibitory amino acid. The content of GABA is low in the striatum of patients with Huntington's disease. The number of NMDA receptor is decreased also in Huntington striatum. These observations may give a clue for the prevention of various neurodegenerative diseases.


[Amino acid metabolism in endogenous psychoses: significance of amino acids as neurotransmitter, precursor of monoamines and allosteric regulator of neuro-receptors].

Amino acid metabolism in endogenous psychoses has been discussed in relation to monoamine synthesis. There are no consistent findings which prove altered monoamine syntheses to be the primary change. Our finding, which suggests decreased amino acid transport across the blood-brain barrier in schizophrenia, does not necessarily mean an insufficient amino acid supply to the brain. Several lines of investigation have shown the possibility of the involvement of glutamatergic dysfunction in the pathogenesis of schizophrenia. Our recent finding of decreased CSF asparagine concentration in schizophrenia and its positive correlation with the response to neuroleptics may support this hypothesis. Recently, free D-serine, an allosteric agonist on NMDA-receptor, has been reported to exist in the rat brain, suggesting that D-serine is an intrinsic ligand. The pathogeneses of endogenous psychoses might be studied in terms of disturbed metabolism of amino acid, as allosteric regulater of neuro-receptor, as well as neurotransmitter and precursor of monoamines.


[A study of DNA ploidy pattern, proliferation index and PCNA in duodenal carcinoma].

12 cases of duodenal carcinoma were studied for nuclear DNA ploidy patterns, the proliferation index (PI), proliferating cell nuclear antigen (PCNA) positive score (1 = 0-25%, 2 = 26-50%, 3 = 51-75%, 4 = 76-100%) and PCNA positive rate. DNA aneuploidy was observed in 9 cases (75%) and PCNA staining was positive in 11 cases (91.6%). DNA ploidy patterns, PI, PCNA positive scores and positive rates were not related to each other. No relationship DNA ploidy patterns for PCNA positive scores and PCNA positive rates could be found. The relationship between PI and PCNA positive score was found not to be significant (P less than 0.10). PI was revealed to correlate significantly (P less than 0.05) to PCNA positive rate.


[Effect of a long-term oral ammonia administration on immunoreactive-somatostatin concentrations of rat stomach].

The effect of a long-term oral ammonia administration on immunoreactive-somatostatin concentrations was investigated in rat stomach. The gastric ir-somatostatin concentrations in the group treated with 0.01% ammonia (pH 9.6) for four weeks were significantly higher than those in both the group treated with 0.1% ammonia (pH 10.4), 0.1 mM-NaOH (pH 9.6), or distilled water (pH 7.0) for four weeks and the group treated with 0.01% ammonia for two weeks. On the contrary, ir-somatostatin levels in the gastric juice and serum tended to decrease with ammonia administration. Further, ammonia administration significantly induced the decrease in mucosal thickness in the pyloric gland area and parietal cell numbers in a dose- and time-dependent manner. From these findings, it was suggested that a long-term oral treatment with 0.01% ammonia, which was clinically estimated as the concentration of the gastric juice in patients with Helicobacter pylori infection, induced not only atrophic changes on gastric mucosa, but the inhibitory effect on somatostatin secretion in rat stomach.


Postsynaptic potentiation of neurotransmission by neurokinin A in rat vas deferens.

Effects of neurokinin A (NKA) on sympathetic neurotransmission were studied in rat vas deferens. Although neither prazosin, an alpha 1-adrenoceptor blocker, nor alpha, beta-methylene adenosine triphosphate, a P2-purinoceptor blocker, inhibited the NKA-induced contractions in the epididymal site, high concentration of NKA-induced contractions in the prostatic site were slightly decreased by either of the two blockers. Treatment with guanethidine, which prevents the release of sympathetic transmitters from presynaptic nerve endings, also had no effect on NKA-induced contractions in either site. To investigate the effects of NKA on the adrenergic and purinergic neurotransmission in more detail, we measured transmitter release by using [3H]norepinephrine or [14C]adenosine. Neither spontaneous or nor evoked 3H efflux, indicating NE release, was affected by NKA in either site. NKA enhanced 14C efflux, indicating ATP release, evoked by electrical stimulation in the epididymal site, which may be originated from smooth muscle. In the prostatic site, contractions induced by electrical stimulation were enhanced in spite of no increase in 3H or 14C efflux. These results suggest that: 1) NKA has no effect on presynaptic nerve terminals in both sites, 2) NKA potentiates the effects of neurotransmitters in the prostatic site, and 3) NKA modulates the neurotransmissions.


[Expression of c-H-ras, c-erb B1 and c-erb B2 gene products in human bladder cancer].

To investigate the expression of c-H-ras (p21), c-erb B1 (EGFR) and c-erb B2 (p185) gene products in human bladder cancer, immunohistochemical studies using monoclonal antibodies to these proteins were performed on formaline fixed (within 15 hours)-paraffin sections of tumor tissues from 20 patients with bladder cancer, normal appearing adjacent bladder (non-tumor) tissues from 11 of the 20 patients, and normal bladder tissues from 3 patients who died of non-cancerous diseases as control. p21 Positive staining was demonstrated in the superficial cells of urothelium in 1 of 3 controls, also in 5 of 20 tumor tissues compact cells without vacuole in cells which have an increased nuclear/cytoplasmic ratio. Seven of 11 non-tumor tissues indicated positive staining either in superficial layer only or in whole layers of urothelium, and 1 of the latter group reacted with the monoclonal antibody to human bladder cancer produced in our laboratory. EGFR was found in 5 of 20 tumor tissues and 7 of 11 non-tumor tissues, but not in controls. Most EGFR positive tissues also indicated p21 positivity except in 1 of the tumor tissues. p185 Positive staining was demonstrated in 9 of 20 tumor tissues and 5 of 11 non-tumor tissues, but not in the controls. Furthermore, 5 of 6 tumor tissues from the patients with lymph node metastasis indicated p185 positivity. These results suggest that both p21 and EGFR may have a role in transformation and that p185 has a role in the development of metastasis in some urothelial malignancies.


[Soluble guanyl cyclase of blood platelets and heart of rats with experimental myocardial ischemia].

The activity of soluble guanylate cyclase (GC) and its regulation in the platelets and heart of normal rats and rats with experimental acute myocardial ischemia provoked by coronary ligation was examined. There was a synchronous reduction in platelet and heart GC activity immediately following 15 minutes after surgery along with a drastically marked drop in genuine baseline activity (with Mg2+) to 19 and 40% in the platelets and heart (both ischemic and intact areas), respectively. Following 24 hours, GC activity insignificantly rose (up to 35.5%) in the platelets with Mg2+, that with Mn2+ remained unchanged; in the ischemic area it decreased much more (to 30%), whereas in the intact area it partially restored (up to 70%). The stimulating effect of DTT on platelet GC activity 15 minutes after the surgery drastically rose (from 2.8 to 8), then returning to normal 24 hours later. The findings show an enhancement in free radical processes typical of ischemia and indicate their high response of platelet GC at the earliest stages. Sodium nitroprusside-induced activation of myocardial GC diminished in the ischemic area in 15 minutes and virtually lacked in 24 hours. There was a less pronounced decrease in GC activation in the intact area. It is suggested that lower enzymatic activatibility is associated with heme loss. The absence of sodium nitroprusside-induced stimulation of platelet GC both in health and in the abnormality under question may be due to primary heme enzymatic deficiency.


[Hyperbaric oxygenation and antianginal agents: effects on blood levels of malondialdehyde and activities of antioxidative enzymes in patients with ischemic heart disease].

The time course of serum levels of malonic dialdehyde and red blood cell activity of antioxidative enzymes, such as superoxide dismutase and glutathione peroxidase, was assessed from the outcomes of hyperbaric oxygenation combined with antianginal therapy in 38 patients with functional classes II-III stable angina on effort without clinical manifestations of circulatory failure. Hyperbaric oxygenation involved 10-12 sessions at 1.5 ata during 40 min each. The antianginal agents (long-acting nitrates, beta-adrenoblockers, nifedipine) were given in median therapeutical doses. The control group included 26 patients who had hyperbaric oxygenation in the same fashion without taking antianginal drugs. The criteria for beneficial therapy were a reduction in the number of anginal episodes and the nitroglycerin tablets used, an increase in exercise tolerance, as evidenced by repeated bicycle ergometric test. The positive clinical effect of a hyperbaric oxygenation course was shown to be accompanied by higher activity of superoxide dismutase in the red blood cells. The use of nifedipine in the multimodality anginal therapy prevents the hyperbaric oxygenation-induced increase in serum malonic dialdehyde levels.


High glucose-induced proliferation in mesangial cells is reversed by autocrine TGF-beta.

We investigated the effects of glucose concentration in serum-free media on the proliferative growth response of a cultured murine mesangial cell line. Raising the ambient D-glucose concentration from 100 mg/dl to 450 mg/dl stimulated cell proliferation after 24 to 48 hours but had a growth inhibitory effect after 72 to 96 hours of incubation. This biphasic proliferative response to high glucose concentration was not mediated by the elevated osmolarity of the medium and did not occur when L-glucose was used. The early phase of glucose-induced proliferation was associated with increased expression of the immediate early genes c-myc and egr-1 as well as with induction of the S-phase related proliferating nuclear cell antigen (PCNA). Several lines of evidence indicated that the late phase of glucose-induced growth inhibition was mediated by the bioactivation of endogenous transforming growth factor beta (TGF-beta). Neutralizing antibody against TGF-beta prevented the late inhibitory effects of glucose on proliferation. On the other hand, exogenous TGF-beta (1 ng/ml) significantly inhibited basal proliferation in mesangial cells. Furthermore, Northern blot analysis revealed that TGF-beta 1 mRNA was induced by 450 mg/dl glucose in the medium after 48 to 72 hours, but not after 24 hours. Cell cycle analysis demonstrated that mesangial cells incubated in high glucose for 24 hours have a higher percentage of cells in the S-G2 phase of the cell cycle compared with cells grown in normal glucose concentration. After 48 hours of culture in elevated glucose concentration, the percentage of cells in S-G2 phase was decreased, and became comparable to that of cells in normal glucose concentration. However, the addition of neutralizing anti-TGF-beta antibody stimulated the progression of cells towards S-G2 in high glucose medium after 48 hours. The findings of this study demonstrate a biphasic growth response of mesangial cells when they were cultured in high glucose concentration; initially there was a transient stimulation of replication for 24 to 48 hours followed by a sustained inhibition after longer incubation periods. This inhibition may be mediated by the glucose-induced synthesis and/or bioactivation of TGF-beta which can inhibit proliferation of mesangial cells in an autocrine fashion.


Maternal and other factors of cryptorchidism--a case-control study in Japan.

A case-control study of cryptorchidism was undertaken in Japan. A hundred and eight mothers of children with cryptorchidism and mothers of their matched controls were surveyed. After 4 pairs which consisted of one of twin siblings either in the cases or the controls were excluded, 104 paired data of singletons were analyzed. As a result, a significantly smaller proportion of the case mothers had suffered from vomiting during the index pregnancy than that of the control mothers (odds ratio, or OR = 0.50, 95% confidence interval, or CI 0.28-0.89). A significantly larger proportion of the case mothers had delivered the index child by vacuum or breech extraction, or Caesarean section than that of the control mothers (OR = 2.09, 95% CI 1.01-3.98). A significantly larger proportion of the case mothers had never breast-fed the index child than that of the control mothers (OR = 3.50, 95% CI 1.20-10.21). Significantly larger proportions of the cases had inguinal hernia (OR = 9.00, 95% CI 1.29-62.97), or congenital cardiac diseases (OR = 8/0, p < 0.05) than those of the controls. It was inferred that endogenous hormonal milieu of a mother, rather than exogenous hormones, might be associated with the occurrence of cryptorchidism.


Colonic epithelial cell proliferation in a rat model of nongenotoxin-induced colonic neoplasia.

The effect on colonic cell proliferation of poligeenan, a nongenotoxic polysaccharide that induces colon tumors in rats, was compared with guar gum and carrageenan. Fischer 344 rats were fed a basal diet supplemented with carrageenan and poligeenan fibers for up to 91 days. The quantitative levels of proliferation, location of the proliferating cells, and the ability of the mucosa to readapt by removing the experimental fibers from the diet were tested. The mucosal epithelium exhibited a 5-fold increase in thymidine kinase activity in both the carrageenan and poligeenan groups. Proliferating cells appeared at the luminal surface only in the poligeenan-treated rats, and the number of proliferating cells in the upper third of the crypt increased 35-fold. A second and third set of animals were fed one of the three test diets for either 28 or 64 days, followed by a 28-day recovery period. Proliferation in the guar- and carrageenan-treated groups returned to basal levels. In poligeenan-treated rats, thymidine kinase levels, and proliferating cells in the upper third of the crypt remained 2- and 11-fold, respectively, above controls. The difference in recovery time between the poligeenan group and the others, and the luminal location of proliferating cells may prove useful as markers in understanding early events in the carcinogenic process induced by a nongenotoxin.


Alterations in the beta-adrenergic receptor system after hypothermic ischemia in hearts with preischemic beta-receptor desensitization.

Although hypothermic cardioplegic arrest is a basic method of myocardial protection in cardiac surgery, the beta-adrenergic receptor (BAR) system has been little investigated in the heart subjected to hypothermic ischemia. Additionally, although the hypothermic arrest is often induced in hearts with preischemic desensitization of the BAR system by preceding congestive heart failure, the functional state of the BAR system after ischemia has not been studied in these hearts. We investigated alterations in the BAR system after hypothermic ischemia in normal rat hearts and in those with preischemic desensitization of the BAR system produced with isoproterenol (ISP: 400 micrograms/kg/hr for 24 hr). Both normal and BAR-desensitized hearts were isolated and subjected either to 40 min of hypothermic (10 degrees C) global ischemia followed by 40 min of reperfusion or subjected to time-matched aerobic perfusion with modified Krebs-Henseleit solution. At the end of perfusion (1) BAR binding properties with [3H]CGP-12177 and adenylate cyclase activity were measured in crude membrane fraction and (2) the inotropic response to ISP (delta LV + dP/dtmax) was evaluated in an isovolumetric contracting heart preparation. Following reperfusion, normal hearts without desensitized BAR showed a higher Bmax value than those of nonischemic time-matched hearts (41.8 +/- 3.1 vs 35.4 +/- 2.4 fmole/mg protein, P less than 0.05), whereas the Kd value was in a similar range in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)


Development of a sensitive and inexpensive micropush-pull technique for the continuous analysis of brain neurotransmitters and metabolites in vivo.

A new, sensitive, convenient, inexpensive and low-maintenance miniaturized triple-cannula system (Zhange et al., 1990) for the push-pull perfusion of brain tissue has been constructed, and tested for its ability to exchange substances in rats, both in vitro and in vivo. In vitro: the cannula was immersed in a vial filled with 1.5 ml of a 1 microM standard solution of norepinephrine, dopamine, and their metabolites. Artificial cerebrospinal fluid was perfused through the system. Perfusate was collected at rates of 1, 2, 5, 10 and 20 microliters/min over 10 min. The recovery rate of the biogenic amines (using high performance liquid chromatography) at 10-min intervals for 60 min was consistent (57 +/- 1.31%) in low flow rate groups (1 approximately 10 microliters/ml). In vivo: [3H]choline (3 microCi, 35 nmol) was infused (6 min) into the lateral ventricle and collected by micropush-pull at 10-min intervals for 180 min, from the cerebellomedullary cistern and hippocampus. The highest [3H]choline count was reached within 10 min after infusion. Levels returned to baseline within 20 min following infusion of the tracer. The micropush-pull cannula was also adapted for chronic brain perfusion in vivo. Recovery of perfused fast green dye (0.00025%) was comparable (83 +/- 1.75%), using the same cannula for 3 sampling periods within 1 month in a freely moving rat. A cresyl violet analysis showed minimal damage to the brain tissue, with gliosis only evident in a narrow margin along the cannula track. Thus the micropush-pull technique is highly efficient in terms of exchange of material, causes minimal damage of brain tissue, and can be used chronically in awake animals. These data have been presented in preliminary form at the 1991 ASPET meetings (Zhang et al., 1991).


Evaluation of quinolinic acid induced excitotoxic neurodegeneration in rat striatum by quantitative magnetic resonance imaging in vivo.

Excitotoxic neurodegeneration in the rat striatum was induced by direct injection of quinolinic acid. The degree of damage was evaluated in vivo 1 day later by quantitative magnetic resonance imaging (MRI) and 7 days later in the same animals by measuring the activities of the neuronal marker enzymes choline acetyltransferase and glutamic acid decarboxylase. Striatal damage assessed using the two approaches was highly correlated. Moreover the cerebroprotective efficacy of the N-methyl-D-aspartate receptor antagonist CGP 40116 was indistinguishable based on all analytical parameters. MRI, however, was more reproducible than the enzymatic methods and was faster and simpler for routine analyses of excitotoxic damage and cerebroprotection in vivo.


Randomised controlled trial of cost-effectiveness of lithotripsy and open cholecystectomy as treatments for gallbladder stones.

Inpatient extracorporeal shockwave lithotripsy for treatment of gallbladder stones has not previously been compared with open cholecystectomy in terms of cost-effectiveness. In a randomised controlled trial, 163 patients, stratified by gallstone bulk (over 4 cm3 or not), were randomised to lithotripsy or cholecystectomy (38 large-bulk and 27 small-bulk cholecystectomy; 37 large-bulk and 61 small-bulk lithotripsy) and followed up for 1 year. Both treatments gave significant health gains in terms of a reduction in episodes of biliary pain, improved perceived health status, and symptom relief, but few differences between treatments were found. There was some evidence that biliary-pain episodes were less severe after cholecystectomy. Cholecystectomy patients also had greater improvements in mean health gain for three related symptoms: vomiting, feeling sick, and fatty-food upset. However, there were no differences between groups in perceived health status. Among lithotripsy patients, health gain was not related to stone clearance. Lithotripsy was more expensive than cholecystectomy, principally because of the costs of the inpatient stay and adjuvant bile-salt therapy. Conventional lithotripsy appears at least as cost-effective as cholecystectomy for patients with small-bulk stones but less cost-effective for those with large-bulk stones. To some extent treatment choice can be guided by patient preference.


20 years or more of follow-up of living kidney donors.

The perioperative and long-term risks for living kidney donors are of concern. We have studied donors at the University of Minnesota 20 years or more (mean 23.7) after donation by comparing renal function, blood pressure, and proteinuria in donors with siblings. In 57 donors (mean age 61 [SE 1]), mean serum creatinine is 1.1 (0.01) mg/dl, blood urea nitrogen 17 (0.5) mg/dl, creatinine clearance 82 (2) ml/min, and blood pressure 134 (2)/80 (1) mm Hg. 32% of the donors are taking antihypertensive drugs and 23% have proteinuria. The 65 siblings (mean age 58 [1.3]) do not significantly differ from the donors in any of these variables: 1.1 (0.03) mg/dl, 17 (1.2) mg/dl, 89 (3.3) ml/min, and 130 (3)/80 (1.5) mm Hg, respectively. 44% of the siblings are taking antihypertensives and 22% have proteinuria. To assess perioperative mortality, we surveyed all members of the American Society of Transplant Surgeons about donor mortality at their institutions. We documented 17 perioperative deaths in the USA and Canada after living donation, and estimate mortality to be 0.03%. We conclude that perioperative mortality in the USA and Canada after living-donor nephrectomy is low. In long-term follow-up of our living donors, we found no evidence of progressive renal deterioration or other serious disorders.


Infant cerebral cortex phospholipid fatty-acid composition and diet.

It has not been established whether nutrition in early infancy affects subsequent neurodevelopment and function. If there is an effect, it seems probable that the essential fatty acids and their metabolites, the major constituents of brain structure, will be the most susceptible to dietary influence. We determined the phospholipid fatty-acid composition of cerebral cortex grey matter obtained from 20 term and 2 preterm infants who had died of "cot deaths" and related results to the milk diet the infants had received. Tissues were analysed by gas chromatography. The mean weight percentage of docosahexaenoic acid was significantly greater (p less than 0.02) in 5 breast-milk-fed infants (9.7%) than in 5 age-comparable formula-milk-fed infants (7.6%). In these formula-fed babies, the overall percentage of long-chain polyunsaturated fatty acids was maintained by increased incorporation of the major n-6 series fatty acids. In 1 formula-fed preterm infant, in whom the lowest concentration of cortical docosahexaenoic acid was found, the compensatory effect was only partial with both n-9 series eicosatrienoic acid or Mead acid and docosatrienoic acid also detected in the phospholipid. Supplementation of formula milks for term infants with docosahexaenoic acid and those for preterm infants with both docosahexaenoic and arachidonic acid could prove beneficial to subsequent neurodevelopment.


Inhaled nitric oxide in persistent pulmonary hypertension of the newborn.

Nitric oxide (NO) has vasodilatory effects on the pulmonary vasculature in adults and animals. We examined the effects on systemic oxygenation and blood pressure of inhaling up to 80 parts per million by volume of NO at FiO2 0.9 for up to 30 minutes by 6 infants with persistent pulmonary hypertension of the newborn (PPHN). In all infants this treatment rapidly and significantly increased preductal oxygen saturation (SpO2); in 5 infants postductal SpO2 and oxygen tensions also increased. Inhalation of NO did not cause systemic hypotension or raise methaemoglobin. These data suggest that low levels of inhaled NO have an important role in the reversal of hypoxaemia due to PPHN.


Low-dose inhalation nitric oxide in persistent pulmonary hypertension of the newborn.

We studied the effects of inhaled nitric oxide (NO) in 9 newborn infants with severe persistent pulmonary hypertension (PPHN) who were candidates for extracorporeal membrane oxygenation treatment. With low doses of NO (10-20 ppm) all showed rapid improvement in oxygenation without reduction of systemic blood pressure. In 6 infants treated with inhaled NO for 24 h, clinical improvement was sustained at 6 ppm.


A large focus of alveolar echinococcosis in central China.

Human alveolar echinococcosis (AE) is a rare and highly pathogenic helminthic zoonosis due to infection with the intermediate stage of the small fox tapeworm, Echinococcus multilocularis. Parasite transmission is restricted to northern latitudes, including central and north China, from where few clinical and no detailed community studies have been reported. In August, 1991, 65 (5%) of 1312 people residing in three rural communes of Zhang County, Gansu Province, China were diagnosed as having hepatic AE after mass ultrasound scanning with serological back-up. This represents one of the highest prevalence rates of AE ever recorded. It is also the first time that mass ultrasound scanning and serology have been used together in an AE endemic region. The region was selected one year earlier, when a preliminary serosurvey on 606 unselected people in the same locality resulted in an 8.8% serum antibody positive rate with a 76% rate of confirmation of hepatic AE in 37 individuals who could be followed up in 1991. Seropositivity rates varied for villages between 0 and 20.5%. Overall, females (7.8%) had a significantly greater risk of infection than males (2.5%), especially in the 31-50 age group, a difference which may be related to contact with dogs and dog faeces over many years. Age-specific prevalence of AE increased from 0% in the under 5-year group to 8.2% in those aged 31-50. The youngest case was 11 years and the mean age of diagnosis was 40 years. Adult tapeworms of E multilocularis were identified from the small intestines of 10% of domestic dogs. Sylvatic animal hosts of the parasite have not yet been identified. The high prevalence of human AE in this region of central China is most probably due to semi-domestic transmission of E multilocularis between wild rodents and dogs, together with the poverty and poor hygiene in these rural communities.


Prospective evaluation of laparoscopic-assisted colectomy in an unselected group of patients.

Laparoscopic technology is likely to have an increasing impact on surgical procedures that have previously required an open approach. We have prospectively evaluated laparoscopic colectomy in 40 patients requiring elective colonic excision mainly for malignant disease. 33 of 40 patients had a successfully completed laparoscopic colectomy, although there was one postoperative death. Seven operations were unsuccessful and required conversion to conventional open laparotomy. Morbidity was low with no wound infections and only two chest infections in the 32 survivors. Early mobilisation and discharge from hospital (mean 8 days) was a notable feature. Previous abdominal surgery was not an absolute contraindication to laparoscopic colectomy. However, the inability to palpate the colon directly to confirm the site of laparoscopically impalpable lesions leads us to recommend contrast radiology to confirm the location of colonoscopically diagnosed lesions before laparoscopically assisted colectomy. Preliminary pathological assessment of resected tumour specimens revealed a satisfactory tumour clearance. We conclude that laparoscopic colectomy is a feasible operation in most patients and leads to a substantial patient benefit without compromising the chance of a surgical cure of cancer.


Long-term symptomless HIV-1 infection in recipients of blood products from a single donor.

There have been reported cases of long-term symptomless human immunodeficiency virus type 1 (HIV-1) infection, but it is not clear whether the benign course of infection was due to host, viral, or other unknown factors. During follow-up of subjects with transfusion-acquired HIV-1 infection in New South Wales, Australia, we identified a group of 6 subjects who had been infected through a single common donor. We were therefore able to study the contributions of various factors to the course of infection. Throughout follow-up (range 6.8-10.1 years after infection), 5 of the recipients and the donor (last follow-up 10.2 years after infection of the first recipient) remained clinically free of symptoms, with normal CD4 cell counts and no p24 antigenaemia. HIV-1 was isolated from only 1 recipient; the isolate did not induce syncytia in a SUPT1 co-culture assay and had a limited in-vitro host range. 1 infected recipient (who had received extensive immunosuppressive treatment for systemic lupus erythematosus) developed Pneumocystis carinii pneumonia and died 4.3 years after infection. The frequency of progression to AIDS or a CD4 cell count below 0.50 x 10(9)/l was significantly lower among the 6 subjects with a common donor (1/6) than among 101 other HIV-infected transfusion recipients for whom data from 7 years of follow-up were available (94/101; p less than 0.0001). These findings suggest that the subjects were infected by a less virulent strain of HIV-1. The identification of this group of subjects should stimulate a search for other similar groups, which will provide important information on the immunopathogenesis of HIV-1 disease.


Haemodynamic effects of tracheal compared with intravenous adrenaline.

If intravenous access is not available during cardiopulmonary resuscitation, tracheal administration of adrenaline 0.02 mg/kg, twice the intravenous dose, is recommended. In a randomised crossover study we investigated the haemodynamic effects of low doses of tracheal versus intravenous adrenaline. 12 anaesthetised patients having a hip replaced received one dose of adrenaline intravenously (0.1 microgram/kg) and the other tracheally (0.5 microgram/kg). There was a mean increase in systolic arterial pressure of 40.5 mm Hg (range 16-81) after the intravenous injection, with little effect on heart rate. Tracheal adrenaline had no effect on arterial pressure or heart rate. Thus low doses of tracheal adrenaline have no haemodynamic effects. We believe that the recommended tracheal dose of twice the intravenous dose is likely to be ineffective for the treatment of cardiac arrest. Animal studies suggest that a tracheal dose at least ten times the intravenous dose is required.


Oligonucleotide genotyping of HLA polymorphism on microtitre plates.

Molecular analysis of mutations and polymorphisms that are of medical importance requires both accuracy and simplicity. In organ transplantation there is a need for an HLA typing procedure that combines the remarkable accuracy of oligonucleotide genotyping with the simplicity of conventional serological typing. We describe a simple semiautomated method of HLA class II typing consisting of an oligonucleotide hybridisation assay done on microtitre plates followed by automatic colorimetric reading. Individual HLA-DR generic typing for 30 DR specificities, including subtypes of DR1, DR2, DR13, DR14, and DR52, is done on a single plate. The entire typing assay can be completed in less than 4 hours. The procedure has been validated on more than a thousand haplotypes in prospective DR typing of kidney transplant patients, leukaemic patients, and their potential donors. The simplicity of this assay makes it suitable for routine laboratory use. It can be applied to genetic testing in general, including the testing of patients with multiple mutations.


Optimum duration of anticoagulation for deep-vein thrombosis and pulmonary embolism. Research Committee of the British Thoracic Society.

The optimum duration of anticoagulation therapy for deep-vein thrombosis (DVT) and pulmonary embolism (PE) is not clear. We have carried out a multicentre comparison of 4 weeks' and 3 months' anticoagulation in patients admitted to hospital with acute DVT, PE, or both. Of 712 patients enrolled, 358 were assigned 4 weeks' treatment and 354 3 months'. Objective confirmation of the diagnosis was obtained in 71%. PE caused or contributed to death in 7 patients (3 treated for 4 weeks, 4 for 3 months). Adverse effects were uncommon, although 1 patient (4-week group) died of haemorrhage. The numbers of patients whose thromboembolism failed to resolve on treatment was lower in the 3-month group than in the 4-week group (13 [3.7%] vs 24 [6.7%], p = 0.10) as was the number who had recurrences (14 [4.0%] vs 28 [7.8%], p = 0.04). Among patients with postoperative DVT or PE the rate of treatment failure and recurrence was low (2.6%) and there was little difference between the treatment groups. By contrast, among medical patients the rate was 12.8%, with a clear difference in favour of 3 months' treatment. If venous thromboembolism arises after surgery, 4 weeks of anticoagulation should be adequate. In other settings, patients with new DVT, PE, or both, who do not have a persisting underlying cause or risk factor should receive anticoagulants for 3 months.


Systemic chimerism in human female recipients of male livers.

We have previously reported data from clinical and laboratory animal observations which suggest that organ tolerance after transplantation depends on a state of balanced lymphodendritic cell chimerism between the host and donor graft. We have sought further evidence to support this hypothesis by investigating HLA-mismatched liver allograft recipients. 9 of 9 female recipients of livers from male donors had chimerism in their allografts and extrahepatic tissues, according to in-situ hybridisation and molecular techniques 10 to 19 years posttransplantation. In 8 women with good graft function, evidence of the Y chromosome was found in the blood (6/8), skin (8/8), and lymph nodes (7/8). A ninth patient whose transplant failed after 12 years from recurrent chronic viral hepatitis had chimerism in her lymph nodes, skin, jejunum, and aorta at the time of retransplantation. Although cell migration is thought to take place after all types of transplantation, the large population of migratory cells in, and the extent of their seeding from, hepatic grafts may explain the privileged tolerogenicity of the liver compared with other organs.


Implications of pulsatile stretch on growth of saphenous vein and mammary artery smooth muscle.

Internal mammary artery (IMA) coronary bypass grafts have a higher patency than saphenous vein (SV) grafts. Intimal hyperplasia and occlusion of venous grafts result from smooth muscle proliferation. Mechanical factors, such as pulsatile stretch, are potential mediators of this process. Smooth muscle cells from IMA and SV were cultured on deformable membranes and exposed to pulsatile stretch (60 cycles/min). This stimulus increased 3H-thymidine incorporation into venous (a two-fold increase) but not arterial smooth muscle cells after 24 h. Smooth muscle cell numbers from SV, but not IMA, were increased (p less than 0.05) after 6 days of stretch. Thus, pulsatile stretch stimulates smooth muscle cell proliferation in SV, but not IMA, and may contribute to venous bypass graft disease.


Apolipoprotein epsilon 4 homozygosity in young men with coronary heart disease.

We have compared apolipoprotein E gene polymorphism in 91 Australian men aged 30-50 who had been referred for coronary angioplasty and in 172 healthy younger men. 5 of the 19 patients who were less than 40 years of age were homozygous for the epsilon 4 allele, representing a 16-fold increase in prevalence compared with controls. In patients aged 40-50 the epsilon 4 allele frequency was 60% higher than it was in controls. Inheritance of epsilon 4 seems to confer risk of premature ischaemic heart disease in males, homozygotes being especially at risk at a younger age.


Importance of complete follow-up of spontaneous fetal loss after amniocentesis and chorion villus sampling.

Women who are the most difficult to trace after amniocentesis or chorion villus sampling are often those who have had an adverse pregnancy outcome. To calculate total fetal loss figures for use in prenatal counselling we have followed in a multicentre study 100% of women who had undergone these procedures. Early spontaneous loss (within three weeks of the procedure) and total spontaneous loss were much lower after amniocentesis (0.2% and 1.3%, respectively) than after chorion villus sampling (1.2% and 2.9%). Four spontaneous fetal losses among the 20 pregnancies that were the most difficult to follow-up increased the loss rate by 0.5% for chorion villus sampling. Risk of early fetal loss after chorion villus sampling was related to experience of the operator (relative risk [RR] 4.3, p = 0.003), and total fetal loss was lower in pregnancies tested at 10 weeks' or more gestational age compared with those tested before 10 weeks' (RR 0.4, p = 0.01). A table showing the frequency of each of the seven possible outcomes after amniocentesis and chorion villus sampling is useful in counselling those considering one or other test.


Randomised trial of case finding and surveillance of elderly people at home.

Health screening for old people who live at home has been the subject of debate for 30 years or so. It has come to the fore again in the UK with the new emphasis on annual assessments by general practitioners (GPs) of those aged 75 or more. Screening in the elderly has implications for manpower. How can it best be done? We describe here a randomised, controlled study of case finding and surveillance in patients aged 65 and over in a general practice in South Wales. Problem identification was by a postal questionnaire, focusing on function, that was sent at random to 369 eligible patients with subsequent verification and intervention by a specially appointed nurse. The 356 controls had no questionnaires and no contact with that nurse. The study lasted 3 years, and end-points included mortality, self-ratings of quality of life, and health status, and use of all services (GP contacts, hospital admission, home help, and so on). Mortality was significantly lower in the intervention group (18%) than in the controls (24%) (difference 6.0% [95% CI 0.1-11.9%], p less than 0.05). Total number of hospital admissions did not differ between intervention and control groups, but duration of hospital stay of patients aged 65 to 74 years was significantly shorter in the intervention group (difference 4.6 days [95% CI 1.6-7.6], p less than 0.01). An increase in visits to a GP was largely offset by a lower number of home visits by a GP. Quality-of-life measures revealed no between-group differences, but self-rated health status was superior in the intervention group. We conclude that the use of a postal screening questionnaire with selective follow-up and intervention can favourably influence outcome and use of health care resources by elderly people living at home.


Role of glucose and insulin resistance in development of type 2 diabetes mellitus: results of a 25-year follow-up study.

Type 2 diabetes mellitus is characterised by resistance of peripheral tissues to insulin and a relative deficiency of insulin secretion. To find out which is the earliest or primary determinant of disease, we used a minimum model of glucose disposal and insulin secretion based on intravenous glucose tolerance tests to estimate insulin sensitivity (SI), glucose effectiveness (ie, insulin-independent glucose removal rate, SG), and first-phase and second-phase beta-cell responsiveness in normoglycaemic offspring of couples who both had type 2 diabetes. 155 subjects from 86 families were followed-up for 6-25 years. More than 10 years before the development of diabetes, subjects who developed the disease had lower values of both SI (mean 3.2 [SD 2.4] vs 8.1 [6.7] 10(-3) I min-1 pmol-1 insulin; p < 0.0001) and SG (1.6 [0.9] vs 2.3 [1.2] 10(-2) min-1, p < 0.0001) than did those who remained normoglycaemic). For the subjects with both SI and SG below the group median, the cumulative incidence of type 2 diabetes during the 25 years was 76% (95% confidence interval 54-99). By contrast, no subject with both SI and SG above the median developed the disease. Subjects with low SI/high SG or high SI/low SG had intermediate risks. Insulin secretion, especially first phase, tended to be increased rather than decreased in this prediabetic phase and was appropriate for the level of insulin resistance. The development of type 2 diabetes is preceded by and predicted by defects in both insulin-dependent and insulin-independent glucose uptake; the defects are detectable when the patients are normoglycaemic and in most cases more than a decade before diagnosis of disease.


Effect of Helicobacter pylori on gastric somatostatin in duodenal ulcer disease.

Infection of the gastric antrum by Helicobacter pylori is associated with recurrent duodenal ulcer disease but the mechanism of ulcerogenesis is unclear. Since pathways inhibiting gastric secretion are defective in patients with duodenal ulcers, we investigated whether H pylori interferes with the normal gastric inhibition that is mediated by somatostatin. We studied 28 patients with active duodenal ulcers in whom H pylori was eradicated successfully. In 18 patients, we measured the density of antral somatostatin-immunoreactive cells and in a further 10 subjects, the amount of somatostatin mRNA before and after eradication of H pylori was determined. After eradication, the median density of somatostatin-immunoreactive cells increased significantly from 9 (range 3-47) to 19 (6-57) cells per mm muscularis mucosa (p = 0.025). The median somatostatin mRNA/rRNA ratio increased from 50 (25-160) to 95 (40-180) (p = 0.01). The number of gastrin cells and quantity of gastrin mRNA did not change significantly. Our results suggest that in duodenal ulcer disease, gastric secretory function is disinhibited through the suppression of mucosal somatostatin.


Association of sleep-wake habits in older people with changes in output of circadian pacemaker.

Many elderly people complain of disturbed sleep patterns but there is not evidence that the need to sleep decreases with age; it seems rather that the timing and consolidation of sleep change. We tried to find out whether there is a concurrent change in the output of the circadian pacemaker with age. The phase and amplitude of the pacemaker's output were assessed by continuous measurement of the core body temperature during 40 h of sustained wakefulness under constant behavioural and environmental conditions. 27 young men (18-31 years) were compared with 21 older people (65-85 years; 11 men, 10 women); all were healthy and without sleep complaints. The mean amplitude of the endogenous circadian temperature oscillation (ECA) was 40% greater in young men than in the older group. Older men had a lower mean temperature ECA than older women. The minimum of the endogenous phase of the circadian temperature oscillation (ECP) occurred 1 h 52 min earlier in the older than in the young group. Customary bedtimes and waketimes were also earlier in the older group, as was their daily alertness peak. There was a close correlation between habitual waketime and temperature ECP in young men, which may lose precision with age, especially among women. These findings provide evidence for systematic age-related changes in the output of the human circadian pacemaker. We suggest that these changes may underlie the common complaints of sleep disturbance among elderly people. These changes could reflect the observed age-related deterioration of the hypothalamic nuclei that drive mammalian circadian rhythms.


Comparison of umbilical-artery velocimetry and cardiotocography for surveillance of small-for-gestational-age fetuses.

Intrauterine growth retardation is associated with an increased risk of fetal asphyxia as well as greater perinatal morbidity and mortality. Ultrasound fetometry enables detection of fetuses that are small for gestational age. Doppler velocimetry of the umbilical artery has good predictive ability for fetal distress, but it is not yet clear whether it could replace cardiotocography in antenatal surveillance of small-for-gestational-age fetuses. We have done a randomised comparison of the two methods. At four obstetric departments in Sweden, women with fetuses found to be small on ultrasound examination at 31 completed weeks of pregnancy or later were randomly assigned to antenatal surveillance with either doppler velocimetry (doppler; 214) or cardiotocography (CTG; 212). Pregnancies in the doppler group were managed according to a protocol based on blood-flow classes deriving from the semiquantitative evaluation of umbilical-artery velocity waveforms; unless the pregnancy was complicated by any other disorder, no antenatal cardiotocography was done. By comparison with the CTG group, the doppler group had fewer monitoring occasions (mean 4.1 [SD 3.1] vs 8.2 [6.2], p < 0.01), antenatal hospital admissions (68 [31.3%] vs 97 [45.8%], p < 0.01), inductions of labour (22 [10.3%] vs 46 [21.7%], p < 0.01), emergency caesarean sections for fetal distress (11 [5.1] vs 30 [14.2%], p < 0.01), and admissions to neonatal intensive care (76 [35.5%] vs 92 [43.4%], p = 0.10). The groups did not differ in gestational age at birth, birthweight, Apgar scores, or total number of caesarean deliveries. Umbilical-artery doppler velocimetry of small-for-gestational-age fetuses allows antenatal monitoring and obstetric interventions to be aimed more precisely than does cardiotocography.


Efficacy of lignocaine analgesia during treatment to the cervix.

There is no consensus amongst physicians about the need for analgesia when a woman undergoes ablative therapy of the cervix. Many doctors believe that the discomfort felt during such procedures is insubstantial. By means of a randomised double-blind placebo-controlled trial, we have shown that patients experience considerable pain during cold-coagulation treatment of the cervix. We found that intracervical lignocaine leads to a significant (p < 0.01) reduction in this pain.


Endogenous benzodiazepine receptor ligands in idiopathic recurring stupor.

"Endozepines" are endogenous ligands for the benzodiazepine recognition sites on gamma-aminobutyric acid A receptors in the nervous system. Idiopathic recurring stupor (IRS) is a syndrome of spontaneous stupor or coma that is not associated with known metabolic, toxic, or structural abnormalities but can be reversed by flumazenil, a pure benzodiazepine antagonist. We measured endozepine-2 and endozepine-4 by high-performance liquid chromatography and radioreceptor assay in serum and cerebrospinal fluid from three patients with IRS. During episodes of stupor there was a large (up to 300-fold compared with control patients) increase of endozepine-4 content in cerebrospinal fluid and serum, but a return to normal concentrations between attacks. Endozepine-4 may contribute to, or be the cause of, IRS. The reasons for abnormal concentrations of endozepine in blood and brain are unknown.


Air pollution and infant mortality in the Czech Republic, 1986-88.

An ecological study of infant mortality and air pollution was conducted in the Czech Republic. Routinely collected data on infant mortality and air pollution in the period 1986-88 were analysed for the 46 of the 85 districts in the republic for which both were available. The independent effects of total suspended particulates (TSP-10), sulphur dioxide (SO2), and oxides of nitrogen (NOx) adjusted for district socioeconomic characteristics, such as income, car ownership, and abortion rate, were estimated by logistic regression. We found weak positive associations between neonatal mortality and quintile of TSP-10 and SO2. Stronger adjusted effects were seen for postneonatal mortality, with a consistent increase in risk from the lowest to the highest TSP-10 quintile (p < 0.001). Weaker and less consistent evidence of a positive association with NOx (p = 0.061) was observed. The strongest effects were seen for postneonatal respiratory mortality, which increased consistently from lowest to highest TSP-10 quintile (p = 0.013). There was also a suggestion of a positive association with SO2 (p = 0.062). The highest to lowest quintile risk ratios for postneonatal respiratory mortality were 2.41 (95% Cl 1.10-5.28) for TSP-10, 3.91 (0.90-16.9) for SO2, and 1.20 (0.37-3.91) NOx. The specificity of the association between air pollution quintile (especially TSP-10) and postneonatal respiratory mortality is consistent with the known effects of air pollution on respiratory disease morbidity in children. These ecological associations require confirmation in an individually based study.


Evidence of prenatal influences on breast cancer risk.

Intrauterine exposure to high concentrations of endogenous pregnancy oestrogens may be important in the aetiology of breast cancer. In a nested case-control study we have assessed the relation between breast cancer risk and indicators of pregnancy oestrogen concentrations; pre-eclampsia/eclampsia is negatively related and measures of fetal size are positively related to oestrogen concentrations. Standard records for women born at Uppsala University Hospital between 1874 and 1954 were linked with records of invasive breast cancer cases, identified through their unique national registration numbers in the Swedish Cancer Registry during 1958-90. For each breast cancer case, we selected as potential controls female offspring of the first three mothers admitted to the hospital after the case's mother; only controls still living in Sweden and free from breast cancer when it was diagnosed in the case were finally included. Conditional logistic regression analysis was done for 458 breast cancer cases and 1197 matched controls. Pre-eclampsia/eclampsia was associated with a breast cancer rate ratio of 0.24 (95% confidence interval 0.09-0.70, p = 0.01). Linear trends for breast cancer incidence with increasing birth weight, birth length, and placental weight were positive but not significant. Thus, prenatal factors are important in breast carcinogenesis. Concentrations of pregnancy oestrogens may be one such factor, but other prenatal or perinatal factors cannot be excluded.


Breast cancer survival among women under age 50: is mammography detrimental?

Great uncertainty exists about the benefit of detecting breast cancer by mammography in women under 50 years of age. We have reviewed the survival of patients aged 49 years or less whose cancers were detected by mammography alone. 117 women under the age of 50 years were diagnosed with breast cancer between 1978 and 1991 based only on an abnormal mammogram. Ductal carcinoma in-situ (DCIS) was found in 47 (40%) of these women, whilst 70 (60%) had infiltrating ductal or infiltrating lobular carcinomas. During the same interval, 928 women in this age group presented with palpable breast cancer. DCIS was diagnosed in 82 (9%) of these women, whilst 846 (91%) had infiltrating carcinoma. Among the infiltrating cancers detected by mammography alone, 50% were stage I, whilst only 30% of the women with palpable cancers were stage I. Five-year survival for all mammographically detected cancer patients was 95%, whereas for women with palpable cancers the survival was 74% (p < 0.00005). If DCIS is not included, the corresponding survivals are 91% for mammographically detected infiltrating cancers and 72% for palpable infiltrating cancers. Only 1 woman who died among those with palpable cancer had had a mammogram before diagnosis. Our data contradict the suggestion that women under 50 are put at a survival disadvantage by undergoing mammography. We believe that investigators who have reported negative results in this age group must examine other causes for their results.


Serum cholesterol, triglycerides, and aggression in the general population.

A higher than expected number of violent deaths and suicides in coronary prevention trials has provoked interest in the possibility that low serum cholesterol concentrations are associated in the general population with personality characteristics predisposing to aggressive and suicidal behaviour. We have investigated this possibility in the Edinburgh Artery Study. We measured serum lipid concentrations in blood samples taken from fasting subjects and assessed personality characteristics on the Bedford Foulds Personality Deviance Scales in a random sample of 1592 men and women aged 55-74 years, selected from age-sex registers of ten general practices in Edinburgh. Serum cholesterol concentration was not significantly associated with aggression in men, but it was associated in multivariate analysis (though not univariate analysis) with denigratory attitudes towards others among women. However, serum triglyceride concentration was related, especially in men, to hostile acts (r = 0.13, p < 0.001) and domineering attitude (r = 0.12, p < 0.001) independently of age, total and HDL cholesterol, cigarette smoking, and alcohol consumption. Subjects taking part in prevention trials have higher triglyceride concentrations than the general population and the relation between serum triglyceride concentration and aggression merits further investigation.


Coronary revascularisation in insulin-dependent diabetic patients with chronic renal failure.

Insulin-dependent diabetic patients found to have substantial coronary artery disease at the time of assessment for renal transplantation have 2-year survival of less than 50%. Because most of these patients have no angina symptoms their management is controversial. We tried to find out whether coronary artery revascularisation in such patients might decrease the combined incidence of unstable angina, myocardial infarction, and cardiac death. 151 consecutive insulin-dependent diabetic candidates for renal transplantation underwent coronary angiography. 31 had stenoses greater than 75% in one or more coronary arteries, atypical chest pain or no chest pain, and a left ventricular ejection fraction greater than 0.35. Of these, 26 agreed to be randomly assigned medical treatment (a calcium-channel-blocking drug plus aspirin) or revascularisation (angioplasty or coronary bypass surgery). 10 of 13 medically managed and 2 of 13 revascularised patients had a cardiovascular endpoint within a median of 8.4 months of coronary angiography (p < 0.01). 4 medically managed patients died of myocardial infarction during follow-up. Thus, revascularisation decreased the frequency of cardiac events in insulin-dependent diabetic patients with chronic renal failure and symptomless coronary artery stenoses. These findings suggest that diabetic renal transplant candidates should be screened for silent coronary artery disease, because revascularisation may decrease cardiac morbidity and mortality in this population.