Acute arsine intoxication as a consequence of metal burnishing operations

The report concerns a 30-year-old factory worker, employed in a small galvanizing plant for over ten years in the burnishing, copper- and nickel-plating of small metal articles for the shoe industry. Acute arsine poisoning was attributed to the use of a dilute solution of CuSO4 (3%), HCl (32%), and As2O3 (2%) for burnishing metal (Fe-Zn) shoelace eyelet holes, in the absence of local exhaust ventilation and with no respiratory protection. Arsine caused severe intravascular hemolysis with a rapid drop in hematocrit and hemoglobin levels. Other body organs were involved as a result of the hypoxic effect of anemia and hemolysis, or as a direct toxic effect of the arsine itself. Our experience confirms that exchange transfusion is capable of rapidly arresting the adverse effects of arsine. The importance of preventive measures and worker information to avoid acute arsine poisoning is emphasized.

The combined use of ultrasound and densitometry in the prediction of vertebral fracture

Measurement of ultrasonographic parameters provides information concerning not only bone density but also bone architecture. We investigated the usefulness of ultrasonographic parameters and bone mineral density for evaluating the probability of vertebral fracture. 397 postmenopausal women (59.1 +/- 6.0 years) with (n = 178) or without (n = 219) atraumatic vertebral fractures were studied. In all women, bone mineral density (BMD) of the lumbar spine was evaluated by dual X-ray absorptiometry (DXA) and speed of sound (SOS); broadband ultrasound attenuation (BUA) and Stiffness in the calcaneus were evaluated by an Achilles unit (Lunar Corporation). Ultrasonographic parameters and BMD were compared by examining the magnitude of the odds ratios, to determine which produces the highest estimate of the probability of odds of fracture, and by examining widths of the respective confidence intervals (CI) to show which estimate of odd ratio is the most precise. The relative risk of vertebral fracture, after adjusting for potential confounders, was 3.5 (CI 2.6-4.8) for BUA; 4.5 (CI 3.2-6.2) for SOS; 5.8 (CI 4.0-8.4) for Stiffness and 7.5 (CI 4.8-11.5) for BMD. Ultrasound (US) parameters were still significant independent predictors of vertebral fracture, even after adjusting for BMD. The relative risk of fracture for a simultaneous decrease by 1 SD of BMD and by 1 SD of each ultrasound parameter was 17.3 (CI 9.4-39.6) for BMD and SOS; 18.3 (CI 8.4-30.6) for BMD and BUA and 22.1 (CI 8.9-52.7) for BMD and Stiffness. Our data suggest that US and BMD provide complementary information which can be combined to improve estimates of vertebral fracture risk.

The usefulness of bone turnover in predicting the response to transdermal estrogen therapy in postmenopausal osteoporosis

Transdermal estrogen therapy is now an accepted form of treatment for postmenopausal osteoporosis. Ninety postmenopausal osteoporotic women were randomized to receive either transdermal estrogen (0.05 mg/day 17 beta-estradiol) and calcium (n = 45) or calcium alone (n = 45). The study period was 2 years. Bone mineral density (BMD) at the lumbar spine (by dual-energy X-ray absorptiometry [DXA]) and markers of bone turnover (alkaline phosphatase, osteocalcin, hydroxyproline, pyridinoline cross-links) were assessed at baseline and after 1 and 2 years. In the estrogen-treated group, BMD showed a significant increase (p < 0.001) both after 1 and 2 years, with a reduction in biochemical markers. To investigate the effectiveness of estrogen treatment of postmenopausal osteoporosis in relation to bone turnover, we also divided the patients on the basis of bone turnover, as assessed by measurement of whole body retention (WBR) of 99mTc-methylene diphosphonate. WBR revealed that 26 patients had high bone turnover (HT) and 55 had low bone turnover (LT). The response to estrogen was greater in the HT patients than in the LT patients; in fact BMD increased by 5.7 and 6.6% in HT patients and by 2.6 and 2.7% in LT patients after 1 and 2 years, respectively. In conclusion, the present study demonstrates that, while the BMD decreases in the patients treated with calcium alone, 2-year treatment with transdermal estrogen increases axial BMD and that the response to estrogen treatment is influenced by bone turnover. Therefore, the evaluation of bone turnover may be useful to identify those postmenopausal osteoporotic women who may especially benefit from treatment with estrogen.

Effects of sodium polystyrene sulfonate on gingival plaque: microbiological investigation and clinical follow-up

A new antiplaque agent was tested on nine subjects. The antiplaque agent, a 5% aqueous solution (p/v) of sodium polystyrene sulfonate, applied on the tooth surfaces by daily topical application for two weeks, caused a statistically significant 30% reduction of plaque index (PI), with corresponding reduction of total bacteria and qualitative modifications of plaque formation with reduction of Gram-negative bacteria.

Homozygous familial hypobetalipoproteinemia. Increased LDL catabolism in hypobetalipoproteinemia due to a truncated apolipoprotein B species, apo B-87Padova

Mutations on the apolipoprotein (apo) B gene that interfere with the full-length translation of the apoB molecule are associated with familial hypobetalipoproteinemia (FHBL), a disease characterized by the reduction of plasma apoB and LDL cholesterol. In this report, we describe an FHBL kindred carrying a unique truncated apoB form, apoB-87Padova. Sequence analysis of amplified genomic DNA identified a single G deletion at nucleotide 12032, which shifts the translation reading frame and causes a termination at amino acid 3978. Two homozygous subjects and seven heterozygous relatives were studied. Although homozygous individuals had only trace amounts of LDL, they were virtually free from the symptoms typical of homozygous FHBL subjects. We investigated the in vivo turnover of radiolabeled normal apoB-100 LDL and apoB-87 LDL in one homozygous patient and two normal control subjects. ApoB-87 LDL showed a similar metabolism in all three subjects, with a fractional catabolic rate more than double that of normal LDL. The rate of entry of apoB-87 in the LDL compartment was also markedly decreased compared with normal apoB-100. The increased in vivo catabolism of apoB-87 LDL was paralleled in vitro by a 2.5-fold increased ability of these particles to inhibit the uptake and degradation of normal apoB-100 LDL by normal human cultured fibroblasts. These results indicate that apoB-87 LDL has an enhanced ability to interact with the LDL receptor, the increased apoB catabolism contributes to the hypobetalipoproteinemia and may explain the mild expression of the disease in the two homozygous individuals.

Effect of withdrawal of pravastatin on biliary lipid composition in humans

Abrupt withdrawal of HMG-CoA reductase inhibitors is associated with increased excretion of cholesterol into bile, but this phenomenon has not been investigated in humans. In order to evaluate whether patients interrupting these hypolipidemic drugs are at increased risk of forming gallstones, pravastatin (40 mg twice a day) or placebo was randomly administered to 16 bile fistula patients for 5 days. Biliary lipid composition was determined in basal conditions and for 5 consecutive days after drug withdrawal. Both biliary cholesterol concentration and saturation increased significantly on the second day after pravastatin withdrawal, but tended to decrease thereafter. Biliary bile acids and phospholipids were not affected. This short-lasting effect on biliary cholesterol excretion was probably the result of a transient increase of hepatic cholesterol synthesis by the up-regulated HMG-CoA reductase in the absence of the inhibitory drug. These results are consistent with the hypothesis that, also in humans, biliary cholesterol excretion could be dependent on the hepatic free cholesterol pool.

[Retrospective study of cervical papillomavirus lesions: early Herpes simplex virus proteins as markers of risk for progression]

Specific types of human papillomavirus (HPV) are currently implicated as etiologic agent of benign and malignant lesions of the genital tract. Previous studies highlighted the presence of early proteins (ICSP 11/12) of Herpes simplex virus type 2 (HSV-2) mainly in HPV infected lesions of the cervix. This paper reports a retrospective study on the clinical course of benign cervical alterations in a 70 women population followed-up for 24 months. HPV and HSV-2 (late and early) antigens were detected by immunoperoxidase; HPV 6/11 and 16/18 were identified by in situ hybridization. All CIN III, vs only one CIN I progressed. The majority of regressions (55%) was CIN I, and 61% was characterized by the negativization of viral markers. There was a cyclic and/or chronic expression of viral antigens in progressed and persistent cases (67% and 53%, respectively). Furthermore, a significant correlation between progression and the presence of ICSP 11/12 protein has been found (89% of cases). The simultaneous detection of ICSP 11/12 and HPV 16/18 in 78% of progressed, and in 13% of persistent lesions was noteworthy. This association (ICSP 11/12 and HPV DNA 16/18) may be considered as a risk factor for progression of the lesions, and supports the hypothesis of a synergism of both viruses in the natural history of cervical cancer: the continuous expression of ICSP 11/12 during herpetic recurrences might act as a mutagenic factor in HPV infected tissues.

[Acute pelvic inflammatory disease: comparison of therapeutic protocols]

Acute pelvic inflammatory disease is a serious medical and economic consequence of sexually transmitted diseases among young women. The aim of the study is to compare the efficacy and safety of gentamycin plus clindamycin with that of ceftazidime plus doxycycline in the treatment of hospitalized patients with acute pelvic inflammatory disease. A total of 78 patients with acute PID, hospitalized in II Obstretic and Gynecologic Clinic of II University of Naples (Italy), entered and randomized into two treatment groups: gentamycin plus clindamycin (N = 40) and ceftazidime plus doxycycline (N = 36). Patients were excluded if they were pregnant or were not over the age of 16 years of had a history of allergy to one of the drugs used in the Study of had hepatic disease or kidney trouble or had IUD. Acute PID was diagnosed by the following criteria: 1) lower abdominal pain; 2) cervical motion tenderness; 3) adnexal tenderness (all three should be present); plus at least one of the following additional criteria: a) temperature over 38 degrees C; b) leukocytosis (greater than 10.500 mm3); c) purulent material from the peritoneal cavity bt culdocentesis; d) inflammatory mass present on binomial pelvic examination and/or sonography; e) erythrocyte sedimentation rate > 15 mm/hr. Patients were enrolled into the study after obtaining informed consent, pretreatment and posttreatment cultures were obtained from the endocervix from Neisseria gonorrhoeae and Chlamydia trachomatis and aerobic-anaerobic bacteria. The study has shown that the acute PID has a polymicrobal origins. Both antibiotic regimens were very effective in the treatment of the PID: a complete recovery was obtained in over 90% of patients.

Ultrasound parameters in osteoporotic patients treated with salmon calcitonin: a longitudinal study

Speed of sound (SOS) and broadband ultrasound attenuation (BUA) of ultrasound (US) in bone have been proposed as alternatives to radiation-based methods for the quantitative assessment of osteoporosis. However, the usefulness of US in monitoring response to treatment in osteoporotic patients has yet to be defined. To compare US with bone mineral density (BMD), we studied 112 osteoporotic women (age range 50-64 years). Seventy-eight of them were treated with salmon calcitonin nasal spray (CT; 200 IU/day, 1 month on and 1 month off) and calcium (500 mg/day); 34 patients were given only calcium. One hundred and four women complied with treatment throughout the 2-year study period. At baseline and after 1 and 2 years we measured BMD at lumbar spine by dual-energy X-ray absorptiometry (DXA), and SOS, BUA and Stiffness index, by an Achilles ultrasound unit. Moreover, biochemical markers of bone turnover (alkaline phosphatase, osteocalcin and hydroxyproline) were also measured at baseline and after 6, 12 and 24 months. In the calcitonin-treated group at the end of the study period BMD had increased by 1.99%, SOS by 0.20%, BUA by 0.88% and Stiffness by 2.12%. By contrast in the calcium-treated group all parameters had decreased (BMD, -2.66%; SOS, -0.55%; BUA, -3.30%; Stiffness, -6.0%) by the end of the study period. The differences between groups were significant for BMD, SOS and Stiffness. At baseline a significant, but weak correlation was found between BMD and US parameters. The correlation coefficients between percentage changes at the end of the study period, in BMD and in SOS, BUA and Stiffness, were all significant (p < 0.001), being 0.41, 0.53 and 0.57 respectively. In conclusion, ultrasound measurements carried out in conjunction with BMD measurements will yield a more comprehensive assessment of skeletal status and may be helpful in monitoring the response to treatment in osteoporotic patients.

Interstitial lung granulomas as a possible consequence of exposure to zirconium dust

A case of interstitial lung granulomas is described in a worker exposed to zirconium compounds. Chest X-rays revealed diffuse slight reticular interstitial radio-opacities (ILO classification, 1/0 s/t). Histological examination of transbronchial biopsy tissue revealed small interstitial nonconfluent granulomas with epithelioid and giant cells showing no central necrosis, with PAS-positive diastase-resistant small weakly birefringent particles in interstitial histiocytes. These histological and stain findings, which are characteristic of zirconium skin lesions and granulomas, suggest zirconium interstitial lung disease.

Heterozygous apolipoprotein C-II deficiency: lipoprotein and apoprotein phenotype and RsaI restriction enzyme polymorphism in the Apo C-IIPadova kindred

Deficiency of apolipoprotein C-II (apo C-II), the cofactor for lipoprotein lipase, results in the familial chylomicronaemia syndrome characterized by severe hypertriglyceridaemia and fasting chylomicronaemia. To investigate the biochemical features of the heterozygous state for apo C-II deficiency, we characterized the lipid, lipoprotein and apolipoprotein profiles in 18 relatives of two affected individuals (brother and sister) homozygous for the apo C-IIPadova gene defect which results in the synthesis of a truncated 36 amino acid apolipoprotein. Carrier status was established in first degree relatives as well as in seven non-obligate heterozygotes by restriction enzyme analysis of amplified apo C-II genomic DNA using RsaI. No significant differences in lipid, lipoprotein and apo C-II levels were observed in heterozygotes when compared to unaffected family members. Thus, in this study, the carrier state was not associated with hypertriglyceridaemia or reduced plasma levels of apo C-II. However, analysis of amplified DNA from members of the apo C-IIPadova kindred by digestion with the enzyme RsaI, which identifies the mutant apo C-II, permitted the identification of heterozygous family members which could not be recognized by measuring either fasting triglycerides or plasma apo C-II levels. This study provides further evidence that apo C-II deficiency syndrome is a heterogeneous disease not only at the molecular level but also on the clinical ground with variable phenotypic expression in heterozygous individuals from different kindreds.

The des-gamma-carboxyprothrombin for the diagnosis of hepatocellular carcinoma

Des-gamma-carboxyprothrombin level was measured by enzyme immunoassay in the plasma of 39 patients suffering from hepatocellular carcinoma and 26 controls. Two of these were anticoagulated by warfarin and revealed very high positive values; the remaining 24, 8 healthy subjects and 16 patients with cirrhosis or chronic hepatitis, were negative. Values indicating pathology were found in 56.40% of patients suffering from hepatocellular carcinoma. All malignancies presenting diameter < or = 3 cm were negative, while high positive levels were found in patients with more advanced neoplasia. The alpha-fetoprotein was increased in 43.58% of the patients with hepatocellular carcinoma and in 6.25% of controls with chronic liver diseases. Positive values for both des-gamma-carboxyprothrombin and alpha- fetoprotein were detected in 12/39 patients. An increase of sensitivity (from 43.58 to 69.23%) in detecting hepatocellular carcinoma was found by the complementary use of the two markers relative to sole use of alpha-fetoprotein.

Cold snare excision of small colorectal polyps

This study describes a new technique for excision of small colorectal polyps in a series of 210 consecutive patients, who had total colonoscopy, and in whom any clotting problems had been excluded. A total of 288 small polyps of 5 mm or less in diameter were transected by mechanical strangulation with a polypectomy snare, but without applying any electrical energy. All polyps were recovered whole and sent for histologic examination. No case of perforation, serious bleeding, or mortality was recorded, nor was there any need for blood transfusion because of sudden or delayed bleeding. Of the small polyps, 56% were adenomas, 43% hyperplastic, and 1% were other types. No invasive cancer was found, but in seven small adenomas severe dysplasia was observed. No correlation between the macroscopic appearance of small polyps at endoscopy and their nature at histology was found. Our data confirm that all visible polypoid lesions of the colon should be removed, and that cold snare excision of small polyps is a safe and effective alternative method of treatment in patients without clotting problems.

Antibodies to Mycobacterium paratuberculosis in patients with Crohn's disease

IgG antibodies against Mycobacterium paratuberculosis protoplasmic antigen were looked for by an enzyme immunosorbent assay in patients with Crohn's disease, Ulcerative colitis, active pulmonary tuberculosis, past pulmonary tuberculosis, and in healthy controls. Serum reactivity for these antibodies was not correlated to PPD skin test positivity without history of mycobacterial disease. A cutoff based on the mean absorbance value of a pool of healthy blood donors was chosen. Positive values were found in 12/24 (50%) patients with active pulmonary tuberculosis and 2/10 (20%) skin-test-positive subjects with past pulmonary tuberculosis as expected, because antigenic sharing is common among different mycobacteria. The control group of blood donors showed borderline positivities in 3/149 cases (2.01%). Positive values were found in 4/108 (3.70%) patients with Crohn's disease and 2/40 (5%) with ulcerative colitis. We conclude that our data do not support a causal relationship between the M. paratuberculosis and Crohn's disease, but occasional patients with inflammatory bowel diseases show unexpected positivities for these mycobacterial antibodies.

Acute effects of HMG-CoA reductase inhibitors on biliary lipids in patients with interrupted enterohepatic circulation

HMG-CoA reductase inhibitors decrease serum cholesterol by inhibiting hepatic cholesterol synthesis, but their influence on biliary lipids is not well characterized. In the present study Pravastatin (80 mg) was administered as a single oral dose to 10 patients with external bile fistula, after 1 week of interruption of the enterohepatic circulation, in order to assess the effect of inhibition of hepatic cholesterol synthesis on biliary lipids in conditions of stimulated bile acid synthesis. Bile was collected every hour for 12 h. On the day before, the same procedure was applied with a placebo, and collected bile used as control. Pravastatin decreased both bile acid and phospholipid concentration to about 60% of basal values; this change was still significant after 10 h. Cholesterol concentration was also decreased to about 70% of basal values, but this change was significant only from the 5th to the 7th h. The per cent of cholic and chenodeoxycholic acid was not affected by the drug, but the ratio of glyco- to tauroconjugated bile acids was decreased to about half the initial values. Bilirubin concentration exhibited a late increase, suggesting a reduction in the bile flow. These results suggest that, in patients with interrupted enterohepatic circulation, biliary excretion of bile acids can be largely dependent on hepatic cholesterol synthesis.

Sodium taurocholate affects prostacyclin constitutive production by cultured human vascular endothelial cells

The prostaglandin system is impaired in cholestasis; bile salts, which are a specific biochemical feature of this condition, have been shown to affect functional properties of cells and tissues, and, in some cases, their action is mediated through an alteration of prostaglandin pathway. Endothelium is a privileged site for the production and the action of arachidonate metabolites-prostacyclin in particular. To determine the effects of bile salts on the properties of vascular endothelium, cultured human endothelial cells were studied. Cholic acid sodium salt was seen to induce a direct injury on endothelial cells, as was demonstrated by a massive dismission of the intracellular radiolabel chromium 51. In the absence of detectable toxic effect, sodium taurocholate caused a significant depression of prostacyclin constitutive production from human endothelial cells. The action of sodium taurocholate was related to its concentration and to the time of exposure, and the alteration of prostacyclin production was found to be reversible. Conversely, the generation of thromboxane A2 was not influenced by this bile salt, which may suggest a specific action of sodium taurocholate on arachidonic acid metabolism. These findings indicate that bile salts may directly alter some functional properties of cultured human endothelial cells and may provide a basis for explaining some generalized manifestations that are observed in pathologic conditions characterized by cholemia.

[Bile salts and spontaneous release of PGI2, TxA2 and fVIII from cultured human endothelial cells]

A normally functioning vascular endothelium is required for vascular tone modulation and blood fluidity. Systemic and local circulatory and coagulation alterations, even to the point of renal failure, may be observed in obstructive jaundice; bile salts are included among the potential pathogenetic factors. To assess the effects of taurocholic acid, glycocholic acid, and cholic acid on the integrity and properties of the endothelium, cultured human endothelial cells (HUVEC) were studied. Taurocholic and glycocholic acids (up to 2000 mumoles/L) did not exhibit any significant effect on 51Cr release from HUVEC after 6 h incubation. Following HUVEC exposure to 2000 mumoles/L of the unconjugated compound, cholic acid, a significant discharge of the radiolabel and LDH leakage in the supernatant were observed, to some extent prevented by the presence of human plasma or albumin (physiologic carrier). Prostacyclin spontaneous release from HUVEC was significantly depressed by both taurocholic and glycocholic acid; the action was related to bile salt concentration (200-1000 mumoles/L) and to the time of exposure (1 to 24 h); the reduced production of PGI2 was demonstrated to be reversible. Conversely, spontaneous TxA2 generation and fVIII release were not affected by the presence of bile salts in culture medium. Previous investigations showed that experimental obstructive jaundice could impair prostacyclin release from rat aortic tissue. The same effect was also demonstrated after in vitro exposure of the vessel wall to jaundiced serum and bile salts alone; furthermore, bile salts exert toxic effects on the integrity of several cells and impair the prostaglandin system of different tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical aspects of tethered cord syndrome in adults. Presentation of 2 cases]

The onset of the tethered cord syndrome is usually in childhood, rarely in adulthood. The Authors report two cases and review the main clinical features of the syndrome.

Psychopathologic features among drug addicts and homosexuals with HIV infection

Personal and familial psychopathological histories and information about early losses were collected and the results of the locus of control test and tests for psychological responses were determined for a series of ninety-two HIV-infected subjects (58 drug addicts; 26 homosexuals; 8 heterosexuals, partners of drug addicts). A higher percentage of drug addicts reported past histories of attempted suicide than the homosexuals. Early loss events were more frequent for homosexuals than for drug addicts. There was a higher psychopathological risk for asymptomatic HIV seropositivity in homosexuals, drug addicts who had attempted suicide, subjects that acknowledged that they have serious illness and subjects with external coping mechanisms rather than internal.

Effect of high pressure on metabolic response to cold in rats

The ability of rats to regulate body temperature in a cool helium-oxygen (heliox) atmosphere at high pressure was studied. Thermoregulatory ability in seven awake rats was assessed in a pressure chamber at 1.5, 21 and 41 ATA by monitoring body temperature and oxygen consumption during a gradual reduction of ambient temperature. Body temperature was measured by a radiotelemetry transmitter implanted into the intraperitoneal cavity. The thermal conductance of the rats increased from 0.37 to 0.75 W kg-1 degrees C-1 as air was substituted by heliox and increased further to 1.47 and 1.81 W kg-1 degrees C-1 as the pressure was increased to 21 and 41 ATA, respectively. At high pressure the rats were able to maintain body temperature until the metabolic rate reached a value of 21.9 +/- 2.0 W kg-1, which corresponds to peak metabolic rate. This occurred at an ambient temperature of approximately 21 degrees C. Below this ambient temperature the rats did not manage to maintain body temperature. The results show that the thermal effector mechanisms of rats respond adequately to a slowly decreasing ambient temperature in hyperbaric heliox environments.

[Diagnostic imaging in a case of mesenteric liposarcoma]

The authors report a case of mesenteric liposarcomas in a 70-year-old patient, describing the instrumental diagnostic procedure in order to show the importance of Computed Tomography (CT) in the diagnosis of this tumor.

Olive-oil-enriched diet: effect on serum lipoprotein levels and biliary cholesterol saturation

The effect of diet enriched with a monounsaturated fatty acid (olive oil) on serum lipoproteins, biliary cholesterol saturation index, and gallbladder motility compared with a standard low-fat diet was evaluated in 11 young volunteers admitted to a metabolic ward. A significant decrease of mean total cholesterol (-9.5%), total apo B (-7.4%), LDL cholesterol (-12.2%), and total triglycerides (-25.5%) was observed after the olive-oil-enriched diet. Total HDL- and HDL-subfractions-cholesterol levels as well as serum apo A-I mean levels remained unchanged. Cholesterol saturation index of the bile and fasting and after-meal gallbladder volumes were unaffected by the enriched diet as compared with the low-fat diet. Olive oil may be a natural fat that can be used for the control of plasma and LDL cholesterol as a valid alternative to polyunsaturated fatty acids.

Multiple imaging modalities in a case of hibernoma

Hibernoma is a rare hypervascular benign tumour that originate from brown fat. A case of hibernoma of the thigh, examined by xeroradiography, ultrasound, CT and angiography, is reported. The characteristics of this tumour are considered.

Modified plasma-derived lipoproteins in human atherosclerotic plaques

Low density lipoproteins extracted from surgical specimens of human atherosclerotic plaques (A-LDL) showed altered electrophoretic mobility indicating a greater negative charge than that of plasma LDL (P-LDL). A-LDL but not P-LDL showed high affinity binding/degradation by human monocyte-derived macrophages; this was inhibited by acetylated LDL but not by native P-LDL. Following injection of 125I-labelled autologous P-LDL prior to reconstructive arterial surgery, polyacrylamide and agarose gel electrophoresis of A-LDL extracted from arterial intima showed that the A-LDL and its apolipoprotein B moiety were derived from P-LDL; the electrophoretic mobility of the product A-LDL was greater than that of native P-LDL. The compositions of arterial intermediate density lipoprotein (A-IDL) and A-LDL differed from those obtained from human plasma intermediate density lipoprotein (P-IDL) and P-LDL. A-IDL showed a reduced triglyceride content and increased esterified and unesterified cholesterol. Although the total cholesterol content of A-LDL was similar to that of P-LDL, there was an increase in unesterified cholesterol and a decrease of cholesteryl ester. These studies indicate that LDL extracted from human atherosclerotic plaque is derived from and modified from P-LDL in vivo. Compared with native P-LDL, A-LDL showed differences in charge and composition, associated with its high affinity binding by the acetyl LDL receptor of human macrophages.

Hereditary hyperlipidemia in the rabbit due to overproduction of lipoproteins. I. Biochemical studies

An inherited metabolic disorder in a strain of New Zealand White rabbits, characterized by marked hypercholesterolemia (394 +/- 100 mg/dl), with moderately elevated or normal triglyceride levels is described. Low density lipoprotein (LDL), intermediate density lipoprotein (IDL) and very low density lipoprotein (VLDL) cholesterol levels were increased. VLDL and IDL, and to a lesser extent LDL, had increased free cholesterol and esterified cholesterol content, and triglyceride content was reduced. Kinetic studies with 131I and 125I-labelled rabbit lipoproteins showed a marked increase in production rates of VLDL apo B and LDL apo B. LDL cholesterol levels were directly related to LDL apo B production rate (r = 0.938, p less than 0.001). Both in hypercholesterolemic and normal rabbits injected with labelled VLDL, the specific activity-time curves of VLDL apo B and LDL apo B did not intersect, indicating that LDL apo B was in part derived from sources other than VLDL. No defect was demonstrated in receptor-mediated catabolism of LDL by cultured skin fibroblasts from hyperlipidemic animals. The fractional catabolic rate of LDL apo B was subnormal, but increased when the expanded LDL apo B pool size was reduced by exchange transfusion; the low fractional catabolism may therefore be attributable, at least in part, to saturation of LDL receptors consequent upon the increased pool size of LDL. The hyperlipidemia in this strain of rabbits may be unique in that the underlying mechanism appears to be overproduction of VLDL and LDL.

Lipoprotein modifications during dietary treatment in patients with primary type V hyperlipoproteinaemia

Type V hyperlipoproteinaemia is a disorder of lipid transport characterized by the accumulation in serum of chylomicrons and very low density lipoproteins. The purpose of the study was the analysis of serum lipids and lipoproteins by ultracentrifugation in nine patients with primary type V hyperlipoproteinaemia before and during dietary treatment. After 30 days of balanced isocaloric diet mean serum triglycerides fell from 25.4 +/- 15.0 (mean +/- SD) to 2.8 +/- 1.7 mmol l-1. At the same time the chylomicrons and the very low density lipoproteins of flotation rate higher than 100 disappeared from the serum while the remaining very low density lipoproteins maintained unaltered their normal protein-lipid composition. After 30 days the low density lipoproteins increased significantly in concentration (from 1.6 +/- 0.8 to 4.1 +/- 1.1 mmol l-1 cholesterol) and their percentage content of cholesterol and triglyceride was increased and reduced, respectively. The highest concentration of intermediate density lipoprotein cholesterol was observed after 15 days of treatment (1.2 +/- 0.6 mmol l-1. The abnormally low concentrations and the physicochemical properties of the high density lipoproteins remained unchanged throughout the study (from 0.6 +/- 0.2 to 0.8 +/- 0.2 mmol l-1 cholesterol concentration) and no high density lipoproteins two (HDL2) were observed at any time. The effects of this treatment were an increase in low density and marginal change in high density lipoproteins which are considered, respectively, a positive and a negative risk factor for atherosclerosis.

Apolipoprotein C-II deficiency syndrome. Clinical features, lipoprotein characterization, lipase activity, and correction of hypertriglyceridemia after apolipoprotein C-II administration in two affected patients

Two patients (brother and sister, 41 and 39 yr of age, respectively) have been shown to have marked elevation of plasma triglycerides and chylomicrons, decreased low density lipoproteins (LDL) and high density lipoproteins (HDL), a type I lipoprotein phenotype, and a deficiency of plasma apolipoprotein C-II (apo C-II). The male patient had a history of recurrent bouts of abdominal pain often accompanied by eruptive xanthomas. The female subject, identified by family screening, was asymptomatic. Hepatosplenomegaly was present in both subjects. Analytical and zonal ultracentrifugation revealed a marked increase in triglyceride-rich lipoproteins including chylomicrons and very low density lipoproteins, a reduction in LDL, and the presence of virtually only the HDL3 subfraction. LDL were heterogeneous with the major subfraction of a higher hydrated density than that observed in plasma lipoproteins of normal subjects. Apo C-II levels, quantitated by radioimmunoassay, were 0.13 mg/dl and 0.12 mg/dl, in the male and female proband, respectively. A variant of apo C-II (apo C-IIPadova) with lower apparent molecular weight and more acidic isoelectric point was identified in both probands by two-dimensional gel electrophoresis. The marked hypertriglyceridemia and elevation of triglyceride-rich lipoproteins were corrected by the infusion of normal plasma or the injection of a biologically active synthesized 44-79 amino acid residue peptide fragment of apo C-II. The reduction in plasma triglycerides after the injection of the synthetic apo C-II peptide persisted for 13-20 d. These results definitively established that the dyslipoproteinemia in this syndrome is due to a deficiency of normal apo C-II. A possible therapeutic role for replacement therapy of apo C-II by synthetic or recombinant apo C-II in those patients with severe hypertriglyceridemia and recurrent pancreatitis may be possible in the future.

Lipoprotein metabolism in patients with elevated lipoprotein-lipase activity in adipose tissue

We have evaluated the relationships between adipose tissue lipoprotein-lipase activity (AT-LPL) or post-heparin plasma lipolytic activity (PHLA) and the composition of circulating lipoproteins in 7 patients with multiple symmetric lipomatosis (MSL). In addition we have investigated the behaviour of serum triglycerides after an oral fat load (1 g triglycerides/kg body weight) in 5 MSL patients and in 5 age and sex matched controls. We found significantly higher values of HDL, HDL2 and HDL3 cholesterol in MSL patients than in controls. Moreover, HDL2/HDL3 cholesterol ratio was higher in MSL patients than in controls, which indicate a predominant increase in HDL2 subfraction. The mean values of AT-LPL in lipomatous tissue was significantly higher than in control tissue. A positive statistically significant correlation was found between AT-LPL activity and HDL, HDL2 and HDL3 cholesterol values. After the fat load the maximal increments of serum triglyceride levels and the triglyceride areas over 8 and 12 h are lower in MSL patients than in controls; there was an inverse, statistically significant correlation between the total PHLA or the extrahepatic PHLA values and the triglyceride areas after lipid load. We conclude that MSL represents a useful naturally occurring model for the study of the role of AT-LPL in the metabolism of triglyceride-rich lipoproteins and in the clearance of lipoproteins in the post-prandial phase.

Evaluation of HDL2 and HDL3 cholesterol by a precipitation procedure in a normal population and in different hyperlipidemic phenotypes

Gidez et al described a double precipitation method with polyanions to separate high density lipoprotein (HDL) subfractions, using sodium heparin to precipitate very low density lipoprotein (VLDL) and low density lipoprotein (LDL) first, and dextran sulphate 15000 to precipitate HDL2 from total HDL afterwards. This method has shown a very good correlation with the data from the analytical and preparative ultracentrifuge. The aim of this work is to use this method to analyse HDL2 and HLD3 levels in a population living in our district. We studied 163 subjects considered as 'normal' on the basis of anamnestic and clinical evaluation and routine analysis and 47 subjects with familial hyperlipoproteinemia (types IIa, IIb, and IV). The results obtained confirmed both the difference in HDL and particularly HDL2 levels between the sexes which other authors had observed with reference methods, and the significant negative correlation between plasma triglycerides and HDL2 levels. This method may be applied easily, is rather cheap and, therefore, may be used more often in future.

Improvement of electroimmunoassay for apolipoproteins B and A-I. (Preliminary observations in postprandial phase)

A reliable method for determining serum apoprotein levels is an essential condition for investigating the role of apoproteins in atherogenesis. Electroimmunoassay according to Laurell has been studied and applied with some modifications for the determination of the two main apoproteins: Apo A-I and Apo B. Apo B immunoplates containing 0.4% v/v of rabbit anti-Apo B antiserum were processed for 4 h at 10 V/cm. Samples were incubated at 52 degrees C for 3 h, diluted and then 10 microliter were seeded in each well. Apo A-I immunoplates (8% v/v of sheep antiserum) were processed for 24 h at 2 V/cm. Agarose gel concentration, exsiccation procedure and staining were the same for both apoproteins. The method was standardized employing a secondary standard consisting of a serum pool obtained from normal subjects. Apo A-I and Apo B levels of the pool have been previously determined employing as primary standards the HDL3 (1.120-1.230 g/ml) and the LP-B (1.035-1.050 g/ml) fractions, respectively, which were isolated by preparative ultracentrifugation. Preliminary observations from a study on 20 healthy volunteers with normal lipid levels revealed different apoprotein levels in young men and women and significant differences between postmenopausal women and women in the fertile age.

Metabolic abnormalities in multiple symmetric lipomatosis: elevated lipoprotein lipase activity in adipose tissue with hyperalphalipoproteinemia

Lipoprotein lipase activity in lipomatous tissue, post-heparin lipoprotein lipase activity in plasma, and the composition and concentration of serum lipoproteins were studied in 15 patients with Multiple Symmetric Lipomatosis (MSL). Extremely elevated lipoprotein lipase activity in adipose tissue was found in MSL patients. Total and hepatic post-heparin plasma lipolytic activity was normal, while a moderate but statistically significant increase of extrahepatic lipolytic activity was present. An abnormal composition of serum lipoproteins, characterized by a significant increase in high density lipoproteins, namely HDL2 subfraction, and apoprotein A-I, was demonstrated. A concomitant decrease in and abnormal composition of low density lipoproteins were found. This lipoprotein pattern is consistent with a newly recognized type of hyperalphalipoproteinemia. Significant correlations were found between serum HDL2 cholesterol values and lipoprotein lipase activity in adipose tissue (as well as between serum VLDL-triglyceride and HDL2 cholesterol values). These observations confirm the role of adipose tissue lipoprotein lipase in triglyceride-rich lipoprotein catabolism. The elevated levels of lipoprotein lipase activity in adipose tissue, in addition to a previously demonstrated decrease in adrenergic-stimulated lipid mobilization, could account for both the abnormal fat accumulation in lipomatous fat cell and for hyperalphalipoproteinemia in MSL patients. The occurrence of MSL in two brothers suggests an inherited enzymatic defect, indicating MSL as a "triglyceride storage disease in adipose tissue".

Relationship between triglyceride-rich lipoprotein (chylomicrons and VLDL) and HDL2 and HDL3 in the post-prandial phase in humans

In order to evaluate the relationship between triglyceride-rich lipoproteins (chylomicrons and VLDL) and HDL during alimentary lipaemia, 12 healthy volunteers, 6 male and 6 female (aged 20--40 yrs), were studied. Cholesterol, phospholipid, triglyceride and protein were evaluated in whole serum, VLDL, LDL and HDL (successively subfractionated in HDL2 and HDL3). Blood samples were collected in a fasting state, 4.5 and 9 h after a 1500 calorie meal (20% protein, 40% carbohydrate, 40% fat). A striking increase in triglyceride-rich lipoproteins after 4.5 h was observed in both sexes, but was more pronounced in males. An increase in phospholipid and triglyceride as well as a slight reduction in cholesterol was evident in HDL after 4.5 h. At the same time both lipids and proteins were decreased in HDL3 and increased in HDL2. This phenomenon is more evident in females, who showed a significantly higher basal HDL2 level. These results suggest a possible metabolic relationship in the post-prandial phase between triglyceride-rich lipoproteins and HDL, and an inverse correlation between HDL2 and HDL3.