Incidence of MS during two fifteen-year periods in the Gothenburg region of Sweden

The average annual incidence of definite and probable MS in Gothenburg was re-investigated. For 1950-1954, 1955-1959 and 1960-1964 it was 4.2, 4.2 and 4.3/100,000/year. For the five-year periods between 1974 and 1988 it was 3.0, 2.7 and 2.0/100,000/year. If possible MS was included, the corresponding incidence for 1950-1964 was 5.2, 5.3 and 5.1, and for 1974-1988 it was 3.9, 3.9 and 4.3/100,000/year. Neurological methods and diagnostic criteria were constant throughout the period. The 1950-1964 incidence was based on personally investigated cases, while the 1974-1988 incidence was based partly on review of Gothenburg neurology records. It is concluded that there has been a significant decrease in the incidence of MS in this area. However, the notified decrease may partly be explained by alterations in the case ascertainment procedure. Since the Swedish measles vaccination program started in 1971, the occurrence of measles has been declining and has practically ceased during the 1980s. The time when a possible influence of mass vaccinations against childhood diseases on MS incidence can be monitored is discussed.

Disposition and retention of mercuric chloride in mice after oral and parenteral administration

The present study compares effects of dose size on whole-body retention and relative organ distribution of 203HgCl2, after oral and intraperitoneal administration to female mice of two strains (inbred CBA/Bom and outbred Bom:NMRI). Using whole-body retention data of oral and intraperitoneal administration, an estimated "true absorption" of a single oral dose of inorganic mercury was calculated to be about 20% at two different dose levels. At the highest oral dose, a delay in fecal elimination of nonabsorbed mercury was observed, indicating a decreased peristaltic rate. The relative hepatic deposition was larger after oral than after intraperitoneal administration, presumably due to a first-pass effect, and a correspondingly lower relative renal deposition was seen. Increasing doses at both exposure routes resulted in increasing relative deposition in liver, stomach, intestines, and spleen but decreasing relative deposition in lungs and kidneys. Bom:NMRI mice deposited a larger fraction of the whole-body burden in the kidneys and a smaller fraction in the livers than did CBA/Bom mice. Comparison to a previous study with male mice (Nielsen and Andersen, 1989) demonstrates that male and female mice deposit similar fractions of their body burden in the liver, while male mice deposit significantly larger amounts of mercury in the kidneys and smaller amounts in the carcass than do female mice. Thus, the toxicokinetics of inorganic mercury in mice depend on dose size, administration route, and sex; the mouse strain is of less importance than the other factors investigated. The absorption of inorganic mercury was estimated to be about 20%, that is, twice as high as earlier estimates.

Mechanism of action of oral contraceptives on carbohydrate metabolism at the cellular level

Although the available scientific data on the undesired metabolic effects of sex steroids have accumulated rapidly, most are of a descriptive nature, and only a few studies elucidate the impact at the cellular level and the possible interrelationship between different metabolic systems. This review summarizes the influence of different contraceptive steroid combinations on glucose metabolism and points to the possible mechanisms behind a disturbance of the euglycemic homeostasis with a concomitant change in lipid metabolism. Today the general concept is that the influence of combined sex steroid products on glucose metabolism is mainly caused by the progestogen components, although artificial estrogens may act synergistically. The diabetogenic effects of the progestogens make it important to consider the development during the last decade of the new more selective progestogens of the gonane type. From recent studies it seems, however, that intake of contraceptive combinations of ethinyl estradiol in combination with these types of gonanes, such as desogestrel and gestodene, may also be accompanied by increased insulin resistance, specifically, a hyperinsulinemic response to a glucose challenge despite unchanged glucose values compared with a baseline test. This is similar to observations made with combinations of ethinyl estradiol and other more traditional types of progestogens of the gonane and estrane type. It is conceivable that the diabetogenic effects of the progestogens are caused by a change in insulin receptor binding or a postreceptor defect in the cellular insulin action. The clinical implications of the diabetogenic effects of the sex steroids are hard to interpret, but more long-term exposure of arterial tissue to elevated concentrations of glucose and insulin results in inhibition of lipolysis and synthesis of cholesterol and triglycerides, which result in the development of lipid-filled lesions--fatty streaks--similar to those of early atherosclerosis.

Spinal arteriovenous malformations: neurological aspects and results of embolization

Twenty consecutive patients with spinal arteriovenous malformations (AVMs) were found to have either a progressive, remitting or remitting-progressive course of disease. A characteristic progressive neurological decline was observed in 11 patients with dural fistulas and a similar decline was seen in 5 of the 9 patients with intradural AVMs. In addition to paraparesis and mixed sensory disorder, which ascended to a level of about T10, areas with spared sensation were occasionally found below this level. All cases with this progressive longitudinal myelopathy showed radiological evidence of a dilated medullary venous plexus. All patients were treated by embolization with only a low frequency of complications. Follow-up data verified a significant improvement of motor and sensory function, mainly during the first year after embolization. Cases with progressive neurological decline (dural and intradural AVMs) stopped deteriorating or improved and cases with a history of acute incidents (intradural AVMs) probably run less risk of acute deterioration.

The distribution of cadmium within the human prostate

Five normal prostates from autopsies of humans aged 61-76 yr were divided into 2 x 24 topographically well-defined pairs of slices that were analyzed for cadmium (Cd) and examined histologically. The corresponding kidney cortex concentrations were also determined. The concentrations in ng Cd/g wet wt were in the range of 50-500 in the prostates and 8,000-39,000 in the kidneys with good mutual correlation. Large variations in Cd concentrations within the prostates were found. The concentrations were highest at the base (near the bladder) and lowest at the apex of the gland. Furthermore, large variations within horizontal layers were found, and this variation was not correlated to the histological amount of stroma or glands.

In vivo and in vitro antibacterial activity of conglutinin, a mammalian plasma lectin

Conglutinin is a mammalian C-type lectin which agglutinates iC3b-coated erythrocytes. Ingram [13] found that euglobulin from bovine serum may confer partial protection against experimental infections in mice. We now present evidence that the protective activity in euglobulin against infections of BALB/c mice with Salmonella typhimurium is mediated by conglutinin. Conglutinin also demonstrated antibacterial activity against E. coli and S. typhimurium in vitro. The expression of this activity required the presence of heat-labile serum factors and peritoneal exudate or spleen cells, but not antibodies to the bacteria. Antibacterial activity was also demonstrated when the bacteria were pretreated with serum at 37 degrees C before incubation with conglutinin and cells. The activity of conglutinin was not observed when factor I-deficient or EDTA-treated serum was used instead of normal serum. The active peritoneal exudate or spleen cells showed adherence to plastic.

Trace element status in alcoholism before and during disulfiram treatment

Trace element status was ascertained in 19 alcoholic patients under long-term treatment with disulfiram and in 12 alcoholic patients treated for the first time; the latter group was re-examined after four weeks of treatment. Both groups were compared to matched controls with a moderate alcohol intake. The copper/zinc ratio in serum was increased in the patients under long-term treatment, and a significant decrease occurred during the first four weeks of treatment in the second group. Blood lead was slightly increased in the second group, but not in the patients under long-term treatment. Blood cadmium was high in both groups, perhaps related to excessive tobacco smoking. Blood mercury concentrations were uniformly low. Urinary nickel excretion in the first group was above reference values, and an increase was seen in the second group during the treatment period. Although trace element concentrations in body fluids may not reflect tissue levels, the results support the notion that trace element balances are influenced by alcoholism and disulfiram treatment.

Effects of recombinant human growth hormone in juvenile Nile crocodiles (Crocodylus niloticus)

1. Recombinant human growth hormone (hGH) showed somatotropic activity in juvenile Nile crocodiles (Crocodylus niloticus). 2. Body weight of crocodiles receiving 3.25 micrograms hGH/g body weight twice a week was increased by 49% after five weeks of treatment, compared to 31% increase in controls. 3. Total length was increased by 15 and 5%, respectively, in the two groups. 4. Food conversion efficiency increased from 28% in the controls to 36% in the hormone injected animals. 5. Cessation of hormone treatment was followed by reduced appetite and decreasing body growth.

Acyclovir concentrations in serum and cerebrospinal fluid at steady state

A long-term clinical trial of acyclovir, 800 mg tid, as a therapeutic agent in multiple sclerosis (MS) is in progress. In three patients paired serum and cerebrospinal fluid (CSF) specimens were sampled after one, four, eight and twelve months of continuous treatment. These samples were collected 1.5 h before or 1.5 h after an oral dose. Acyclovir concentrations were assessed by radioimmunoassay. In the CSF, the acyclovir concentration was relatively stable, with a mean of 0.83 microM, while the serum acyclovir concentration was variable with mean peak and trough concentrations of 4.08 and 2.47 microM, respectively. In two other MS patients the acyclovir concentration time profile in serum and CSF was studied at steady state during the 8 h dose interval. In this study the acyclovir concentration in the CSF was only slightly affected by the fluctuations in serum and the acyclovir CSF/acyclovir serum ratio was apparently not influenced by the blood-brain barrier function. We found no indication of an accumulation of acyclovir in cerebrospinal fluid after one to twelve months of oral treatment.

Oral mercuric chloride exposure in mice: effects of dose on intestinal absorption and relative organ distribution

Human intoxications with inorganic mercury occur via the oral or pulmonar routes. However, earlier experimental studies of the acute toxicity of inorganic mercury primarily used parenteral administration of soluble inorganic mercury salts. The present study evaluated the effect of dose size on intestinal absorption and relative organ distribution of orally administered mercuric chloride. Experiments were performed with male mice of 2 strains (inbred CBA/Bom and outbred Bom: NMRI). At the highest dose of HgCl2, a delay in fecal elimination of non-absorbed mercury was observed indicating a decreased peristaltic rate. The fractional whole-body retention of mercury at 14 days after dosage was inversely related to the dose size, conceivably due either to saturation of the uptake mechanism or to damage to the kidneys resulting in loss of mercury with the urine at the highest dose levels. The relative organ distribution of mercury after oral exposure was quantitatively different from that reported in the literature after parenteral administration of inorganic mercury. Thus, the relative hepatic deposition was larger than after injection of mercury, presumably due to the first pass effect. A dose dependency in the relative organ distribution of retained mercury was observed, characterized by increasing relative deposition in liver, stomach, intestines, testes, spleen and carcass but decreasing relative renal deposition with increasing dose. The toxicokinetics of inorganic mercury was similar in the 2 mice strains. The present study demonstrates that the toxicokinetics of orally administered inorganic mercury is different from that of parenterally administered inorganic mercury as earlier reported in the literature.

Effects of diethyldithiocarbamate and tetraethylthiuram disulfide on zinc metabolism in mice

Chronic alcoholics with cirrhosis often develop symptoms of zinc deficiency. Tetraethylthiuram disulfide (TTD) is metabolized to two molecules of diethyldithiocarbamate (DDC). DDC chelates divalent metal ions, including zinc, by forming highly lipophilic neutral bis(dithiocarbamate)-metal complexes. DDC could therefore enhance the intestinal zinc uptake or increase the rate of zinc excretion. Accordingly, treatment of alcoholism with TTD could either aggravate or alleviate zinc deficiency. The present study investigated effects of DDC and TTD on intestinal zinc uptake and on the rate of zinc excretion in mice. When given as very high single oral doses, DDC and TTD increased the intestinal uptake of a single oral dose of zinc. When added to the diet and administered in lower doses, closer to those administered to humans for treatment of alcohol abuse, both compounds were without effect on the rate of excretion of the body's zinc stores. In a long-term experiment, where 65Zn was administered in the drinking water, these doses of TTD and DDC reduced the whole-body retention of 65Zn. No treatment changed the organ distribution of zinc in any of the experiments. In conclusion strong indications emerge from the present study that TTD treatment of alcoholism is more likely to reduce the intestinal zinc absorption than to enhance it as has been suggested by other authors. Thus, the widely used experimental model using single oral exposure to metal and chelator conceivably may give erroneous results, when used to predict effects of prolonged exposures.

Effects of recombinant human growth hormone and insulin-like growth factor 1 on body growth and blood metabolites in brook trout (Salvelinus fontinalis)

Groups of juvenile brook trout (Salvelinus fontinalis) were acclimated to 12.0-13.0 degrees dechlorified water and a photoperiod of 12 hr light: 12 hr dark. Recombinant human growth hormone (hGH) (10.0 micrograms/g body wt) or insulin-like growth factor 1 (hIGF-1), used in a wide range of dosages (0.001-10.0 micrograms/g body wt), were given weekly as intramuscular injections. The fish receiving hGH were already significantly heavier and longer than the saline-injected control fish after 3 weeks of treatment. In addition, a liver specific growth promoting effect of hGH was found. In contrast, hIGF-1 did not stimulate body growth in any dosage tested. The fish receiving the highest dosages of hIGF-1 were all seriously affected with retarded body growth and high mortality. A possible insulin-like activity of hIGF-1 was verified by measuring the plasma glucose and amino acid levels in brook trout after a single injection of hIGF-1 (2.0 micrograms/g body wt) or bovine insulin (0.01 IU/g body wt). Both hormones caused a reduction in both glucose and amino acid levels to 35% of the control levels 24-72 hr after injection. The results strongly suggest that hIGF-1 does not stimulate growth, but that in high dosages causes profound insulin-like effects in brook trout resulting in hypoglycemia and hypoaminoacidemia.

Isolation of herpes simplex virus type 1 during first attack of multiple sclerosis

Herpes simplex virus type 1 was isolated from the cerebrospinal fluid of a patient during the first attack of multiple sclerosis. This is the first virus to be isolated from the central nervous system of a living patient with MS. The virus was identified as herpes simplex virus type 1 by restriction endonuclease analysis and by an enzyme immunoassay using monoclonal antibodies. Antibodies against type 1 but not type 2 were detected in consecutive samples of serum and cerebrospinal fluid. The patient has since entered a progressive phase of multiple sclerosis. The isolated type 1 strain might be of pathogenetic relevance to the development of multiple sclerosis in this patient.

Effect of nickel chloride on hepatic lipid peroxidation and glutathione concentration in mice

Intraperitoneal administration of nickel chloride enhanced hepatic lipid peroxidation (HLP) in 6-wk-old and 8-12-wk-old male CBA-mice but not in 3-wk-old mice. Nickel chloride administration depleted hepatic GSH in 8-12-wk-old mice but not in the younger age groups. After 300 mumol NiCl2/kg mortality occurred among 8-12-wk-old mice but not among the younger mice. Stimulation of GSH synthesis by administration of L-2-oxothiazolidine-4-carboxylate reduced nickel chloride induced mortality and HLP. Reduction of GSH synthesis by administration of buthionine sulfoximine (BSO) did not, however, enhance the toxicity of nickel chloride. This might be owing to chelation of the Ni(II)-ion by BSO. The results demonstrate age dependency and a protective effect of enhanced GSH synthesis in nickel chloride stimulated HLP.

Effects of diethyldithiocarbamate on the toxicokinetics of cadmium chloride in mice

Diethyldithiocarbamate (DDC) efficiently alleviates the acute toxicity of injected cadmium chloride, but enhances the acute toxicity of orally administered cadmium chloride. Further, DDC induces extensive changes in organ distribution of cadmium, and mobilizes aged cadmium depots. The present study investigates effects of DDC on the toxicokinetics of cadmium at lower doses of cadmium than those used in previous studies. During single exposure to subtoxic oral doses of cadmium chloride DDC enhanced intestinal cadmium absorption, both after intraperitoneal and oral administration of DDC. In such acute exposure experiments orally administered DDC only slightly changed the relative organ distribution of absorbed cadmium, while intraperitoneal administration of DDC induced extensive changes in organ preference of absorbed cadmium. The relative hepatic and testicular deposition was reduced, while the relative deposition in heart, spleen, lungs, brain and carcass was increased. Bi-weekly intraperitoneal injections of DDC enhanced the rate of elimination of aged cadmium depots and changed the organ distribution of retained cadmium, compared to the control group. Chronic exposure to DDC in the feed and cadmium chloride in the drinking water did however not result in increased whole-body retention, and the organ distribution in the DDC-exposed group was similar to that in the control group. This result could be due to both increased rate of absorption and increased published extensive changes in the toxicokinetics of cadmium induced by DDC are mainly due to the high cadmium doses employed and the intraperitoneal administration of DDC. At lower doses and more realistic administration routes for cadmium and DDC, the effect of DDC is less. However, still DDC does not seem to have any potential as an antidote for cadmium or for mobilization of cadmium depots in humans.

Purification and characterization of Atlantic salmon prolactin

Prolactin was isolated from the Atlantic salmon (Salmo salar) pituitary gland by extraction with acid acetone, gel filtration, ion exchange-chromatography, and reversed-phase high-performance liquid chromatography. The yield was 0.6 mg/g wet tissue. The hormone had a molecular weight of 23.5 kDa as determined by SDS-polyacrylamide gel electrophoresis. Isoelectric focusing gave an isoelectric point of 9.2. The N-terminal sequence and the amino acid composition indicated extensive homology between Atlantic and Pacific salmon prolactin. Antiserum against Atlantic salmon prolactin cross-reacted with chum salmon prolactin, but not with human, rat, or sheep prolactin.

Effects of dithiocarbamates on intestinal absorption and organ distribution of cadmium chloride in mice

Earlier publications have demonstrated that diethyldithiocarbamate (DDC) antagonizes the acute toxicity of injected CdCl2 but enhances the acute toxicity of orally administered CdCl2, most likely due to the high lipophilicity of DDC and the complex formed with the Cd++ ion. This study demonstrates that the hydrophilic dithiocarbamates dihydroxyethyldithiocarbamate (DHE-DTC) and N-methyl-N-glucamyl dithiocarbamate (NMG-DTC) also enhance the intestinal absorption of orally administered CdCl2 in mice, although less efficiently than DDC. After oral as well as intraperitoneal administration 15 min. after a single oral dose of CdCl2 the dithiocarbamates tested enhanced the intestinal cadmium uptake with a relative efficiency, DDC greater than DHE-DTC greater than NMG-DTC, which correlated to the lipophilicity of both the dithiocarbamates and the complexes formed with the Cd++ ion. Intraperitoneal administration of DDC induced extensive changes in the relative organ distribution of absorbed cadmium, compared to the distribution of CdCl2 administered alone. However, the only noticeable effect of administration of DHE-DTC and NMG-DTC was decreased gastrointestinal deposition of cadmium, irrespective of the administration route of the dithiocarbamates. Earlier studies have demonstrated that DDC and various other dithiocarbamates are capable of mobilizing intracellular cadmium deposits, presumably due to some lipophilicity. This study demonstrates that these dithiocarbamates may also enhance the intestinal absorption of cadmium.

Effects of tetraethylthiuram disulfide on the toxicokinetics of cadmium in mice

This study examines the effects of tetraethylthiuram disulfide (TTD; disulfiram, Antabuse) on the toxicokinetics in mice of 109Cd-labelled cadmium chloride, as determined by whole-body and organ gamma-counting. At the highest single dose of orally administered CdCl2, i.e. 70 mumol/kg, orally administered TTD enhanced the inhibitory effect of CdCl2 on intestinal motility and increased the fractional whole-body retention of the dose of cadmium chloride, indicating enhanced intestinal cadmium absorption. Also, TTD induced extensive changes in organ distribution of absorbed cadmium; the relative hepatic and testicular deposition was reduced, while the relative deposition in heart, spleen, lungs, brain and carcass was increased. In a prolonged exposure experiment where CdCl2 was added to the drinking water and TTD to the feed, TTD increased the intestinal absorption of cadmium by more than four-fold as compared to the controls. Further, decreased deposition was seen in the carcass and increased deposition in intestines and liver. In a third experiment, oral doses of TTD given twice weekly had no influence on the rate of excretion of aged cadmium depots, and also the organ distribution was unchanged. Thus, the effect of TTD on cadmium metabolism seems to be exerted only during intestinal absorption and the distribution phase immediately thereafter.

Effects of macromolecular chelators on intestinal cadmium absorption in mice

Suppression of absorption by macromolecular chelators have been successful with several metals. In this paper a series of immobilized chelators ranging from DTPA to S-containing soft bases have been synthetized and investigated for ability to suppress intestinal uptake of 109Cd2+ in mice. Dextran-0-ethyl-mercaptan, xanthates derived from polysaccharides and polyvinyl alcohol, dithiocarbamates of polyethylene imine and aminoethyl cellulose, and DTPA immobilized on aminopropyl silica were all ineffective. DTPA immobilized on aminoethyl cellulose even enhanced the intestinal uptake. The macromolecular chelators were without extensive effect on organ distribution of absorbed cadmium, except for dithiocarbamate immobilized on polyethylene imine, which enhanced the deposition of cadmium in several organs including the brain. Although the results are discouraging, they indicate that design and synthesis of immobilized vicinal dithio compounds may represent an avenue for development of non-absorbable chelators with high affinity for cadmium.

Early fall of circulating iron and rapid rise of lactoferrin in septicemia and endotoxemia: an early defence mechanism

Total serum iron, plasma lactoferrin and circulating leukocytes were measured in piglets during the early phase of severe gram-negative septicemia and endotoxemia in 3 experimental settings: intravenous (i.v.) infusion of lipopolysaccharide (LPS) (n = 8), i.v. infusion of live Escherichia coli (n = 7) and intraperitoneal (i.p.) infusion of E. coli (n = 6). Iron dropped significantly during the first 30 min of LPS infusion from a median of 32 microM to 13.4 microM. A similar decrease in serum iron was demonstrated in the 2 other groups with minimum values at 120 min after the start of E. coli infusion. Plasma levels of lactoferrin increased significantly 120 min after the start of LPS infusion (median 6 mg/l) when compared to preinfusion values (0.25 mg/l). After i.v. infusion of E. coli a significant rise of plasma lactoferrin was demonstrated already 30 min after bacterial infusion (to 2.1 mg/l) compared to preseptic values (0.8 mg/l). This increase was accompanied with a significant drop of circulating leukocytes (to 7.3 x 10(9)/l) compared to before the infusion (17 x 10(9)/l) in the pigs given E. coli i.v. After i.p. E. coli infusion no significant change of plasma lactoferrin was observed. The rapid fall of total serum iron seen during endotoxemia and E. coli septicemia may in part be explained by the release of lactoferrin from granulocytes and the clearance of iron-bound lactoferrin in the blood or peritoneal cavity.

Adipocyte insulin receptor binding and lipogenesis at term in normal pregnancy

Lipogenesis in subcutaneous abdominal adipocytes during late human pregnancy was investigated by studying insulin receptor binding, 3-O-methyl-(14C-(U]-glucose flux and incorporation of (14C(U]-glucose into CO2 (oxidation) and total lipids (lipogenesis) in adipocytes from 18 health pregnant women undergoing Caesarean section at term, and 19 non-pregnant women undergoing gynaecological surgery. The cell diameter and fasting insulin were increased in the pregnant women, compared with controls (P less than 0.01 and P less than 0.05, respectively). The insulin receptor binding, 3-O-methyl-glucose flux, and basal oxidation were similar in both groups. Basal lipogenesis was higher in adipocytes from pregnant women than from controls (P less than 0.05), but the maximally stimulated increment was similar in both groups. Basal and maximally stimulated lipogenesis correlated positively with the cell diameter (P less than 0.001 and P less than 0.05, respectively). The findings indicate that lipogenesis in subcutaneous abdominal adipocytes from pregnant women is increased due to post-receptor events and that adipocytes do not contribute to the insulin resistance in late pregnancy.

Measurement of exchange of trace metals between the body and its surroundings with the use of tracer methodology. A critique of current applications

Application of general tracer theory to the problem of estimating fluxes of tracee between the gastrointestinal tract and the body proper, from observations of the movement of tracer, shows that a number of assumptions must be fulfilled. Two specific sets of assumptions are discussed and, in both cases, measurement of tracer fluxes yields information on the integrated absorption of the tracee.

Oral cadmium chloride intoxication in mice: diethyldithiocarbamate enhances rather than alleviates acute toxicity

Diethyldithiocarbamate (DDC) is known to alleviate acute toxicity due to injection of cadmium salts. However, when cadmium chloride was administered by the oral route, DDC enhanced rather than alleviated the acute toxicity; both oral and intraperitoneal (i.p.) administration of DDC had this effect. Thus, orally administered DDC enhanced cadmium-induced duodenal and ileal tissue damage and inhibition of peristalsis, as indicated by an increased intestinal transit time. At low cadmium doses, the whole-body retention of cadmium was increased by oral DDC administration. Intraperitoneally administered DDC increased cadmium-induced acute mortality and testicular necrosis, and it enhanced cadmium-induced reduction of intestinal motility and increased the whole-body retention of cadmium, indicating increased intestinal cadmium absorption. Also, DDC changed the organ distribution of absorbed cadmium: after i.p. administration of DDC, the relative hepatic deposition was reduced, whereas the relative deposition in other organs, in particular the brain, was increased. This study indicates that medical use of DDC should be avoided in individuals with current exposure to cadmium.

Oral cadmium chloride intoxication in mice: effects of chelation

In acute oral cadmium intoxication, the immediate target organ is the gastrointestinal tract. In this study, toxic effects following oral administration of CdCl2 to mice by stomach tube included intestinal paralysis, constipation and necrosis of the gastrointestinal epithelia. Tissue damage in liver, kidneys and testes developed in survivors due to the systemic toxicity of absorbed cadmium. Chelation of the Cd2+ ion by STPP, EDTA or DTPA prior to oral administration reduced mortality, tissue damage and whole body retention of cadmium. Other chelators (cysteine, NTA, DDC) only marginally affected the whole-body retention. DDC even enhanced the inhibition of intestinal motility caused by cadmium. DTPA and DDC decreased the relative deposition in the liver and increased the relative renal deposition. DDC also increased the relative cadmium deposition in brain, lung, spleen and testes. Among the chelators tested, DTPA was most efficient in preventing toxic effects of oral cadmium.

Oral cadmium chloride intoxication in mice: effects of penicillamine, dimercaptosuccinic acid and related compounds

The antidotal efficacies of chelators during acute cadmium intoxication has previously been examined in experiments where both a soluble cadmium salt and the chelator were administered parenterally. In the present study, PA, DMSA and related compounds were studied as oral antidotes during oral CdCl2 intoxication. According to the antagonistic effects noted on mortality, peristaltic toxicity and intestinal cadmium uptake, the relative efficacies of the compounds tested were: DMSA greater than PAD greater than DMPS greater than MSA greater than PA greater than NAPA. None of the chelators induced major changes in the organ distribution of absorbed cadmium, in particular no increased cerebral deposition of cadmium. This study indicates that, in oral cadmium intoxication in humans, orally administered DMSA would be likely to offer protection against the local toxicity of cadmium in the gastrointestinal tract as well as to reduce the risk of systemic toxicity of absorbed cadmium.

Effect of cadmium chloride on hepatic lipid peroxidation in mice

Intraperitoneal administration of cadmium chloride to 8-12 weeks old CBA-mice enhanced hepatic lipid peroxidation. A positive correlation between cadmium chloride dose and level of peroxidation was observed in both male and female mice. A sex-related difference in mortality was not observed but at a dose of 25 mumol CdCl2/kg the level of hepatic lipid peroxidation was higher in male mice than in female mice. The hepatic lipid peroxidation was not increased above the control level in 3 weeks old mice, while 6 weeks old mice responded with increased peroxidation as did 8-12 weeks old mice. The mortality after an acute toxic dose of cadmium chloride was the same in the three age groups. Pretreatment of mice with several low intraperitoneal doses of cadmium chloride alleviated cadmium induced mortality and lipid peroxidation. The results demonstrate both age dependency and a protective effect of metallothionein induction on cadmium chloride induced hepatic lipid peroxidation.

Interaction of cadmium ions with calcium hydroxyapatite crystals: a possible mechanism contributing to the pathogenesis of cadmium-induced bone diseases

Cadmium ions adsorb onto calcium hydroxyapatite crystals (HA) and are as effective as inorganic pyrophosphate and aluminum ions in retarding the rate of in vitro dissolution of HA. In contrast, cadmium ions have no important retarding effect on the growth of HA, but are built into the crystals, thus making them very resistant to subsequent dissolution. These effects could interfere with bone remodeling, with cadmium protecting normal sites of resorption and thus causing resorption at pathological sites.

Oral cadmium chloride intoxication in mice: effects of dose on tissue damage, intestinal absorption and relative organ distribution

The acute toxicity of soluble cadmium salts has almost exclusively been studied experimentally after parenteral exposures, where acute mortality is caused by hepatic necrosis. This report describes an alternative experimental model using oral exposure. A single oral toxic dose of CdCl2 to mice induced toxic gastroenteritis; subsequent hepatic and renal lesions were also observed. Whole-body gamma-counting after a single oral toxic 109CdCl2 dose to mice showed a dose-dependent delay of the fecal excretion of non-absorbed cadmium. This delay was absent when a low, non-toxic dose was administered. This effect is most likely due to decreased peristalsis and, at higher doses, intestinal atony due to oral cadmium toxicity. After fecal elimination of non-absorbed cadmium, the residual body burden of cadmium expressed as percent of initial dose reflects the fractional intestinal cadmium absorption due to slow reexcretion of absorbed cadmium. The fractional absorption increased with increasing doses of cadmium. The relative cadmium deposition in brain, testes and intestines decreased with increasing dose, whereas the relative liver deposition increased with dose. The delayed fecal elimination and increased fractional absorption of cadmium may significantly contribute to the development of both local and systemic toxicity in oral cadmium intoxication.

Lactoferrin as an indicator of septicemia and endotoxemia in pigs

The levels of plasma lactoferrin (LF) in response to endotoxin and Escherichia coli infusions in piglets were studied to obtain exact time relation of plasma LF increase in relation to start of endotoxin and E. coli infusions. A new enzyme-linked immunoassay of swine LF is presented. 13 piglets had a 10-fold rapid increase of plasma LF concentrations after 0.25 mg/kg endotoxin intravenous infusion. The initial rise was 3.4 mg/l/h. 14 piglets, receiving 1 x 10(11) E. coli intravenously, showed a higher increase of plasma LF concentrations, amounting to 6-9 mg/l/h. Thus, plasma LF was an early marker of septicemia and endotoxemia.

Glucose tolerance and insulin receptor binding to monocytes and erythrocytes in patients with cystic fibrosis

Cystic fibrosis (CF) is the most frequent life threatening hereditary disease in the Western World with an incidence of approximately 1:2000. Due to increasing survival rates the high frequency of abnormal glucose tolerance has become an important problem. We compared insulin concentrations during oral glucose tolerance test and insulin receptor binding to both monocytes and erythrocytes from 9 patients with CF, with results from 10 healthy controls of similar body weight. The insulin: glucose ratio was increased in the fasting state (p less than 0.05) in patients with CF compared to controls, indicating an increased insulin resistance in CF-patients. The total insulin secretion during oral glucose tolerance test as judged by the area beneath the insulin curve was similar in the two groups, but insulin secretion was significantly delayed in patients with CF. Insulin receptor binding to monocytes and the number of receptors were significantly increased (p less than 0.01 and 0.02, respectively) in patients with CF whereas the dissociation constant was similar in patients with CF and controls. No difference was observed in insulin receptor binding to erythrocytes between the two groups. No correlations were found between insulin receptor binding to monocytes or erythrocytes and glucose tolerance or insulin concentrations.

Insulin receptor binding to monocytes and erythrocytes in gestational diabetes

Insulin receptor binding to monocytes and erythrocytes was measured at the time of diagnosis and again postpartum in 23 normal weight gestational diabetics. In 16 women, insulin receptor binding was studied after a period of dietary treatment. In patients diagnosed early in pregnancy, an increase in insulin binding to both monocytes and erythrocytes was observed during dietary treatment (p less than 0.001), while no similar changes were observed in patients diagnosed later in pregnancy. Postpartum, insulin receptor binding to erythrocytes decreased in all women compared to the time of diagnosis (p less than 0.01) while insulin binding to monocytes either decreased (p less than 0.001) or remained unchanged depending on the time of diagnosis. Insulin binding was similar in those women who remained glucose intolerant and those who returned to normal glucose tolerance postpartum. The findings indicate that factors other than insulin receptor binding are involved in the pathogenesis of gestational diabetes.

Unemployment and mortality in Denmark, 1970-80

Relative mortality in the period 1970-80 was studied among Danish men and women who were unemployed and employed on the day of the 1970 census. The study population consisted of the total labour force in the age range 20-64 on 9 November 1970--that is, about 2 million employed and 22,000 unemployed people. Relative mortality was analysed by a multiplicative hazard regression model (as a natural extension of the standardised mortality ratio) and a multiplicative regression model with extra-Poisson variation. A significantly increased death rate (40-50%) was found among the unemployed after adjusting for occupation, housing category, geographical region, and marital state. Analysis of five main causes of death showed increased mortality from all causes, but especially from suicide or accidents. In areas where the local unemployment rate was comparatively high the relative mortality among the unemployed was lower. The increased mortality among the unemployed was interpreted as a consequence of health related selection as well as increased susceptibility associated with the psychosocial stress of unemployment.

Clinical observations of effects on central nervous system in patients with acute facial palsy

Twenty-eight consecutive patients with acute unilateral facial palsy were examined with special reference to clinical signs of central nervous system involvement. The clinical investigation in the acute stage of the disease showed that only seven patients had solitary facial nerve dysfunction, while the remaining patients had evidence of more widespread disease involvement. The most frequent finding was a trigeminal dysfunction of the paretic side, as shown by paresthesia and sensibility disturbance corresponding to the sensoritrigeminal area, as well as a dysfunction of the trigeminal component of the corneal reflex of the paretic side. Three patients showed migrating symptoms that were suggestive of a brain-stem disorder. In addition, four patients had an optic neuropathy, while an abnormal brain-stem audiometry response was demonstrated in five patients. The outcome of acute facial palsy one to two years after onset, however, could not be predicted from the clinical central nervous system signs. The degree of the palsy in the acute stage of the disease still seemed to be one of the most important prognostic factors. It is concluded that acute facial palsy is not a single entity, but rather a feature of different neurologic conditions.

Elevated levels of myelin basic protein in CSF in relation to auditory brainstem responses in Bell's Palsy

Myelin basic protein (MBP) in the cerebrospinal fluid (CSF) was quantified from 28 patients with acute facial palsy. The mean value of MBP in CSF in the study group was 3.4±0.22 μg/1 (mean±SEM), which was significantly higher than the found in 37 healthy subjects (2.4±0.13 μg/1). Using a 95% confidence interval, 10 patients demonstrated significantly increased CSF concentrations of MBP (>3.95 μg/I). Auditory brainstem response (ABR) test showed that 5 patients had abnormal brainstem responses. No significant correlation was observed between elevated MBP in CSF and either pathologic auditory brainstem responses or the clinical degree of the palsy. These results suggest that a brainstem involvement may occur in patients with Bell's palsy. Furthermore, our data accord with previous reports suggesting Bell's palsy to be part of a polyneuropathy.

Oral contraception and insulin sensitivity: in vivo assessment in normal women and women with previous gestational diabetes

The sensitivity to insulin (euglycemic clamp technique) was assessed in previous gestational diabetic women (n = 6) and nondiabetic women (n = 6) before and twice during low-dose triphasic oral contraceptive administration (ethinyl estradiol and levonorgestrel) for 6 months. Both groups had normal plasma glucose and insulin levels during oral glucose tolerance tests before and during treatment. In vivo peripheral insulin action was measured during insulin infusion of 40 mU/m2 X min with plasma glucose clamped at fasting levels. Before treatment glucose infusion rates were identical in both groups [1.56 +/- 0.12 (SEM) mmol/m2 X min and 1.51 +/- 0.09 mmol/m2 X min, respectively]. After hormonal treatment for 6 months the amount of glucose infused decreased significantly in the previously gestational diabetic women (1.10 +/- 0.12 mmol/m2 X min, P = 0.01), whereas the decrease was less pronounced in the nondiabetic women (1.30 +/- 0.22 mmol/m2 X min, P = 0.09). The decrease in insulin sensitivity was not sufficient to alter glucose tolerance either in the previous gestational diabetic women nor in the nondiabetic women.

Elevated levels of myelin basic protein in CSF in relation to auditory brainstem responses in Bell's palsy

Myelin basic protein (MBP) in the cerebrospinal fluid (CSF) was quantified from 28 patients with acute facial palsy. The mean value of MBP in CSF in the study group was 3.4 +/- 0.22 micrograms/l (mean +/- SEM), which was significantly higher than the found in 37 healthy subjects (2.4 +/- 0.13 micrograms/l). Using a 95% confidence interval, 10 patients demonstrated significantly increased CSF concentrations of MBP (greater than 3.95 micrograms/l). Auditory brainstem response (ABR) test showed that 5 patients had abnormal brainstem responses. No significant correlation was observed between elevated MBP in CSF and either pathologic auditory brainstem responses or the clinical degree of the palsy. These results suggest that a brainstem involvement may occur in patients with Bell's palsy. Furthermore, our data accord with previous reports suggesting Bell's palsy to be part of a polyneuropathy.

The high resolution R-banded karyotype of Rattus norvegicus

Representative haploid R-banded karyotypes of the laboratory rat and diagrammatic representation of the banding patterns at the 525-band level are presented.

Choroideremia: further evidence for assignment of the locus to Xq13-Xq21

Choroideremia is an X-linked hereditary retinal dystrophy leading to blindness in early adulthood. RFLP analyses in three Danish families were consistent with close linkage between choroideremia and the locus DXYS1, located at Xq13-Xq21. Measurable linkage was found between choroideremia and DXS17, at Xq22. Furthermore, choroideremia was diagnosed in a boy with an interstitial deletion at Xq13-Xq21, strongly suggesting the assignment of the locus for choroideremia to this region of the X chromosome. The deletion also covered DXYS1, but did not include DXS17.

Choroideremia in interstitial deletion of the X chromosome

An earlier reported family with a deletion of the proximal long arm of the X chromosome was reinvestigated with special attention to the presence of choroideremia. Two females were identified as carriers of choroideremia while a tapeto-retinal dystrophy was ascertained in a mentally retarded boy. RFLP analysis revealed that the interstitial deletion covered the locus DXYS1 and not DXS17. Chromosome studies indicated a deletion within the Xq21 area.

Oral contraceptives and insulin receptor binding in normal women and those with previous gestational diabetes

The effect of a low-dose triphasic oral contraceptive (ethinyl estradiol and levonorgestrel) on glucose tolerance, plasma insulin response to a glucose challenge, and insulin receptor binding to monocytes and erythrocytes was investigated in seven women with previous gestational diabetes and seven nondiabetic control subjects. Investigations were performed in the luteal phase before the hormonal intake and after hormonal treatment for 2 and 6 months. Before treatment, women with previous gestational diabetes had significantly impaired glucose tolerance (p less than 0.05) when compared with the healthy controls, but no differences in insulin receptor binding were observed. Glucose tolerance and the insulin response to oral glucose remained unchanged in both groups during the treatment period. In the control subjects a significant decrease (p less than 0.05) in insulin receptor binding to monocytes was observed after hormonal intake for 6 months whereas the insulin receptor binding remained unchanged in the women with previous gestational diabetes. No correlation was found between the receptor binding data obtained from monocytes and erythrocytes in either group of women. The study demonstrates that in lean nondiabetic women and women with previous gestational diabetes of normal weight without first-degree history of diabetes there is no apparent direct association between glucose tolerance, plasma insulin levels, and insulin binding to erythrocytes and monocytes during intake of low-dose oral contraceptives.

Insulin receptors in normal pregnant women and women with gestational diabetes

In a serial study of insulin receptor binding to monocytes from normal pregnant women, a significant increase in insulin binding in mid pregnancy followed by a significant decrease in late pregnancy at tracer insulin concentration was found. No changes in the insulin concentration necessary to reduce tracer binding by 50% (ID50) were observed. At delivery, binding to isolated adipocytes was significantly lower in normal pregnant women than in non-pregnant normal controls while no difference in ID50 was observed. No differences in insulin binding at tracer insulin concentration to monocytes and adipocytes between normal weight women with gestational diabetes and healthy non-diabetic pregnant controls were found, but the ID50 was significantly lower in women with gestational diabetes diagnosed in late pregnancy than in pregnant controls at the same weeks of gestation.

Insulin receptor binding to monocytes and erythrocytes during normal human pregnancy

In normal human pregnancy glucose tolerance deteriorates gradually in spite of a steady increase in plasma insulin levels. To see whether this change in insulin resistance is accompanied by changes in insulin receptor binding, insulin binding to monocytes and erythrocytes was measured serially during pregnancy and again post-partum in fifteen normal women. Insulin binding to monocytes increased from week 12 to week 24 of gestation (P less than 0.001) and it decreased from week 32 to week 36 (P less than 0.05). After delivery a new increase in insulin binding to monocytes was seen (P less than 0.05). Insulin binding to erythrocytes increased from week 30-32 to week 36 (P less than 0.05), decreased from week 36 to delivery (P less than 0.01) and decreased further post-partum (P less than 0.001). Insulin receptor binding was not significantly correlated to plasma insulin, estradiol, estriol, progesterone or cortisol. The insulin receptor binding to monocytes, but not to erythrocytes, paralleled the insulin resistance found in human pregnancy.

The peritoneal cell carcinogenicity test

The peritoneal cell carcinogenicity test, which is a new short-term in vivo-in vitro transformation test invented by Nashed (1981), was evaluated in the present report. The experimental design and materials used were as close as possible to those used by Nashed (1981). Test compounds were the two carcinogenic/non-carcinogenic analog pairs benzo[a]pyrene/pyrene and 2-acetylamidofluorene/4-acetylamidofluorene. All 4 compounds were administered orally. Al(OH)3 was injected intraperitoneally to act as mitogen for peritoneal macrophages. The criterium for transformation was colony growth of macrophages in soft agar. Two transformed cell types formed colonies under the conditions used. Pulmonary and peritoneal macrophages formed colonies when colony-stimulating factor was added. No colony growth was observed on plates with macrophages from 256 animals tested (100 carcinogen treated, 80 treated with noncarcinogenic analogs and 76 untreated controls). Thus we were not able to confirm results published previously by the inventor of this test (Nashed, 1981).

alpha-Methyldopa for climacteric hot flushes. A double-blind, randomized, cross-over study

The effects of single evening doses of alpha-methyldopa and placebo have been compared in 40 women with climacteric hot flushes. The study was designed as a double-blind, randomized and cross-over investigation. Of the 24 patients who completed the study, 15 reported that they preferred the alpha-methyldopa treatment (p greater than 0.05). alpha-methyldopa seemed to affect both the severity (p less than 0.05) and the frequency of climacteric hot flushes (p greater than 0.05). It is concluded that alpha-methyldopa is efficacious against climacteric hot flushes when given as single evening doses, but further study is required to answer whether this dosage is as effective as a twice daily regimen.