A qualitative assessment of developmental toxicity within a series of structurally related dopamine mimetics.

A qualitative assessment of developmental toxicity within a series of 12 structurally related compounds, 11 of which were active dopamine mimetics and one was inactive, was conducted in rats treated orally by gavage during the major period of organogenesis. Doses were chosen where possible to be equipotent in terms of pharmacological activity. The series was typified by the compound BRL 16644 (2-[[3,4-dihydro-2,2-dimethyl-4-[3-(trifluoromethyl)phenyl]- 2H-1-benzopyran-7-yl]oxy]-N,N-dimethyl-ethanamine: Chemical Abstracts No. 59257-24-8). Five of these compounds were clearly teratogenic producing specific abnormalities typified by anasarca, brachygnathia and cleft palate. Similar levels of maternal toxicity, particularly stereotypic behaviour, and foetotoxicity were seen in both teratogenic and non-teratogenic compounds suggesting that neither maternal nor foetotoxicity plays a role in the aetiology of the abnormalities. Four of the teratogenic compounds contained a trifluoromethyl group in the 4-phenyl ring and, within this series of compounds, substitution with this group appears to confer teratogenicity. Although equipotent doses were used this only pertained to the adult and as only limited pharmacokinetic data were available, including the extent of placental transfer, the influence of this group is not clear. Investigations have been undertaken to relate the teratogenic potential of these compounds to a number of their chemical descriptors, including electronic, steric, quantum chemical and hydrophobicity parameters, to try and clarify the influence of the trifluoromethyl group.


Multivariate quantitative structure-toxicity relationships in a series of dopamine mimetics.

The techniques of principal components analysis and non-linear mapping are routinely used by computer chemists at SmithKline Beecham Pharmaceuticals in the process of drug development by relating the structure of a compound to its chemical activity. To our knowledge these techniques had not previously been applied to the association between the structure of a compound and its toxicological properties. Using a series of 12 structurally related compounds (11 were active dopamine mimetics and one was inactive), of which five were known to be teratogenic and seven were non-teratogenic, it was possible to demonstrate that molecular modelling techniques could be applied to differentiate toxicological data. The structure/property relationships of these compounds were investigated using calculated physicochemical properties, molecular modelling and multivariate statistical techniques. A data set of 56 molecular descriptors was used to represent this series of compounds. Analysis of the data set using principal components analysis and non-linear mapping suggested that teratogenicity was associated with four molecular properties. Moreover, the electronic nature of the 4-phenyl group appeared to be an important determinant of the teratogenesis.


In vitro evidence for the role of glutamate in the CNS toxicity of mercury.

Intoxication with elemental mercury vapor or with methylmercury results in the accumulation of mercuric mercury (Hg2+) in the brain. Submicromolar concentrations of Hg2+ were shown previously to inhibit glutamate uptake in astrocyte cultures selectively and reversibly. This finding suggests that blockade of the inactivation of synaptically released glutamate is a potential mechanism of the CNS toxicity of Hg2+. The present study shows further that Hg2+ (< or = 1 microM): (i) markedly inhibits the clearance of extracellular glutamate both by astrocyte cultures and by spinal cord cultures; (ii) reduces glutamine content and export in astrocyte cultures; (iii) has little effect on neuronal viability in spinal cord cultures in the absence of excitotoxic accumulations of glutamate; (iv) does not impair the sensitivity of neurons to the excitotoxic action of glutamate. Also, it is noted that Hg2+ (< or = 1 microM) has not been shown to impair transmitter release acutely in existing studies of presynaptic actions. Thus, the available evidence from in vitro studies is consistent with the hypothesis that low concentrations of mercuric mercury in the brain can cause neurotoxicity by selectively inhibiting the uptake of synaptically released glutamate, with consequent elevation of glutamate levels in the extracellular space.


Glutamate transmission is involved in the mechanisms of neuronal degeneration produced by intrahippocampal tetanus toxin in rats.

Tetanus toxin (TT) blocks GABA-mediated inhibitory neurotransmission in the mammalian CNS via selective inhibition of transmitter release. The loss of central inhibition produces an excitatory focus resembling human limbic epilepsy. We now report that the net excitation caused by an unopposed action of glutamic acid may also produce neuronal degeneration in the rat brain. Anaesthetized rats were placed in a stereotaxic frame and TT (1 microliter dissolved in phosphate buffer, pH 7.0) was injected unilaterally into the dorsal hippocampus. Injection of TT (1000 mouse minimum lethal doses, MLDs; n = 3-6 rats per group) produced time-dependent neuronal loss in the CA1 pyramidal cell layer which was significant (p < 0.05) 7 and 10 days, but not 1 day, after the injection. Systemic treatment with competitive (CGP 37849, 3 mg/kg i.p) or non-competitive (MK801, 0.3 mg/kg i.p.) antagonists at the N-methyl D-aspartate (NMDA) receptor complex 1 h before and 1 h after TT and then once daily for 10 days protected rats from the hippocampal damage produced by TT (1000 MLDs). In addition, in rats bearing a monolateral surgical lesion of the Schaffer collaterals, through which CA1 neurones receive a robust excitatory input from CA3 pyramids, the bilateral injection of TT (1000 MLDs/side) produced significant neuronal loss in the unlesioned hippocampus whereas the contralateral appeared to be preserved. In conclusion, these results demonstrate that excitatory neurotransmission may be involved in the neuropathology elicited by intrahippocampal TT in rats.


Computed tomography of the brain, hepatotoxic drugs and high alcohol consumption in male alcoholic patients and a random sample from the general male population.

Computed tomography (CT) of the brain was performed in a random sample of a total of 195 men and 211 male alcoholic patients admitted for the first time during a period of two years from the same geographically limited area of Greater Stockholm as the sample. The same medical, social and neuroradiological methods were used for examination of the alcoholic inpatients as for the random controls. Laboratory tests were performed, including liver and pancreatic tests. Toxicological screening was performed and the consumption of hepatotoxic drugs was also investigated and the following were the types of drugs used: antiarrhythmics, antiepileptics, antiphlogistics, mixed analgesics, barbiturates, sulphonamides, benzodiazepines, clomethiazole and phenothiazine derivatives, all of which are metabolised by the liver. The group of male alcoholic inpatients and the random sample were then subdivided with respect to alcohol consumption and use of hepatotoxic drugs: Group IA, men from the random sample with low or moderate alcohol consumption and no use of hepatotoxic drugs; IB, men from the random sample with low or moderate alcohol consumption with use of hepatotoxic drugs; IIA, alcoholic inpatients with use of alcohol and no drugs; and IIB, alcoholic inpatients with use of alcohol and drugs. Group IIB was found to have a higher incidence of cortical and subcortical changes than group IA. Group IB had a higher incidence of subcortical changes than group IA, and they differed only in drug use. Groups IIB and IIA only differed in drug use, and IIB had a higher incidence of brain damage except for anterior horn index and wide cerebellar sulci indicating vermian atrophy. Significantly higher serum (S) levels of bilirubin, gamma-glutamyl transpeptidase (GGT), aspartate aminotransferase (ASAT), alanine amino-transferase (ALAT), creatine kinase (CK), lactate dehydrogenase (LD) and amylase were found in IIB. The results indicate that drug use influences the incidence of cortical and subcortical aberrations, except anterior horn index. It is concluded that the groups with alcohol abuse who used hepatotoxic drugs showed a picture of cortical changes (wide transport sulci and clear-cut or high-grade cortical changes) and also of subcortical aberrations, expressed as an increased widening of the third ventricle.


Molecular design of cholera vaccines.

Cholera is still a serious public health problem in developing countries, particularly those in tropical regions. This has stimulated considerable research into the molecular analysis of pathogenesis resulting in the identification of a number of critical components required for both colonization of the gut mucosa and the disease symptoms. These components are the targets for rational molecular approaches to vaccine development.


[The "Emmerich Arthritis Record", function and acceptance within the scope of an integrated treatment concept].

For a comprehensive model of rheumatoid arthritis treatment, we designed an arthritis manual for continuous treatment of chronic illness. One goal of introducing the manual to the patients was the improvement of communication between patient and different doctors and therapists. The first part includes of a doctor's documentation sheet and a patient calendar (6 months each) for daily self-documentation of drug compliance. The second part is a daily pain-rating scale. The 3-year evaluation of 655 patient manuals for 286 patients was analyzed to estimate the compliance in using the manual. Overall, 87% of diagnoses, 83% of disease-modifying anti-rheumatic drugs (DMARDs), 87% of non-steroidal anti-rheumatic drugs (NSAIDs) had been documented in the manual. Data indicates that the general practitioner and the rheumatologist accepted the manual form. In addition, 85% of the documented patients used the DMARDs, 74% used the daily pain score, and 43% the daily physiotherapy. Subgroup data (n = 130 RA patients) suggest additional results: 1) there was no difference in sociodemographic data between the patient manual user group and the non-user group; 2) the user group consisted of patients with higher disease activity (ARA-criteria), higher pain score, and negative mood pattern. Furthermore, the user group was more active in daily physiotherapy, ergotherapy, and balneotherapy.


[The importance of S-100 protein positive Langerhans cells and Leu-M1 positive tumor cells for prognosis of papillary thyroid cancer].

In a period of 10 years (1981-90) papillary thyroid carcinomas were found in 124 cases. In 95 cases we were able to perform immunohistochemical studies for Leu-M1 antigen and S-100 protein. The examination of these cases has revealed that the presence of S-100 positive Langerhans cells yields no additional information for the prognosis of the papillary thyroid carcinoma. But we observed that the existence of Leu-M1 positive tumour cells is connected with a poor postoperative course of disease in comparison to Leu-M1 negative tumours.


Spermatic and peripheral venous plasma concentrations of immunoreactive inhibin in prepubertal boys with undescended testis and in pubertal boys with varicocele.

To obtain more information about testicular inhibin secretion in the prepubertal and pubertal human male, we measured the concentrations of immunoreactive inhibin with a heterologous radioimmunoassay in the spermatic and peripheral venous plasma of 5 prepubertal boys with unilateral undescended testis (Group I, P1), 3 prepubertal boys with inguinal hernia (Group II, P1), and 12 pubertal boys with left idiopathic varicocele. The latter subjects were divided, according to the degree of their pubertal development, in early pubertal (Group III, N = 5, P2) and mid-pubertal groups (Group IV, N = 7, P3-4). In Group I, the mean (+/- SD) spermatic venous concentrations of inhibin (289.4 +/- 120.4 ml eq/l) were significantly higher than the corresponding mean peripheral venous concentrations (162.6 +/- 47.2; p < 0.02) suggesting active testicular secretion of inhibin. In Group II, the spermatic-peripheral inhibin gradient was not significant. In pubertal boys with idiopathic varicocele, the mean concentrations of spermatic inhibin were 1076.6 +/- 532.0 and 1023.4 +/- 274.5 in Groups III and IV, respectively. These levels were about five times higher than the corresponding peripheral concentrations (204.8 +/- 41.9 and 238.9 +/- 38.9; p < 0.005 and p < 0.001, respectively). When the data of all the boys were considered together the spermatic venous concentrations of inhibin were significantly correlated with those of peripheral venous FSH (r = 0.4749, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


Increased hypothalamic somatostatin mRNA following dexamethasone administration in rats.

There is increasing evidence to suggest that supraphysiological doses of glucocorticoids suppress growth hormone secretion in vivo by augmenting somatostatin release from the hypothalamus; previously, we reported an increase in hypothalamic somatostatin content in dexamethasone-treated rats. To further examine whether the production of somatostatin really is augmented, hypothalamic somatostatin mRNA levels were determined by the Northern blot technique in female rats receiving 330 micrograms of dexamethasone daily for three days. In two series of experiments, hypothalamic somatostatin mRNA levels in dexamethasone-treated rats were significantly (p < 0.05) increased to 133 +/- 19 (mean +/- SD)% and 153 +/- 38% of the controls. In the dexamethasone-treated rats, plasma growth hormone levels were markedly suppressed compared with those of the controls. These results further support the hypothesis that pharmacological doses of glucocorticoids increase the production and release of somatostatin from the hypothalamus and thus inhibit growth hormone secretion, overriding the direct stimulatory effect of glucocorticoids on growth hormone production at the pituitary level.


[Extra-articular fractures near the knee and concomitant knee damage].

While the prognosis of intra-articular fractures of the knee joint is determined by the reconstruction of the articular surfaces, ligamentous damage and resulting joint instability is a main problem with extra-articular fractures neighbouring the knee. In a follow-up of 43 cases of A 1-3 fractures according to the AO/ASIF classification, 37.2% of the patients revealed concomitant ligamentous damage. Especially supracondylar femoral fractures and the avulsion fractures of the posterior cruciate and lateral collateral ligament are at higher risk.--Ligamentous ruptures accompanying avulsion fractures should be treated primarily according to the rules of knee joint surgery. In cases of supracondylar femoral fractures after open reduction and internal fixation the recovery of knee joint motion is more important than joint stability. Therefore ligamentous repair has to be performed secondarily if necessary.


[Double plate compound osteosynthesis. A procedure for primary stress-stable management of problem injuries of the subtrochanteric to supracondylar femoral area].

Full loading capacity cannot be achieved with standard implants in reversed trochanteric, subtrochanteric and supracondylar femur fractures. A full loading capacity is essential for elderly patients because a load free mobilisation is not possible and in pathological and impending pathological fractures because of the short life expectancy of these patients. On the basis of a proposal by Ganz we developed a double plate compound osteosynthesis (DPCO) with very high loading capacity for all these types of fractures. The technique is presented.


[Application of the Isler and Ganz classification of pelvic ring fractures in clinical practice].

The classification of pelvic fractures proposed by Isler and Ganz was applied to 152 patients. On the basis of this experience, the following conclusion were drawn. 1. It is possible to classify all pelvic ring injuries by dividing them in lesions of the anterior and of the posterior ring segment. 2. The classification requires a thorough examination; often a CT scan is needed. The original classification of 9 out of 18 patients based on X-ray morphology had to be revised after CT examination. 3. Once the pelvic injury is definitely classified the mode of therapy is determined as well.


[Results of surgical treatment of proximal biceps tendon rupture].

During a 9-year period we operated on 19 patients in whom the proximal tendon of the biceps brachii muscle had been disruptured. Various surgical techniques were employed, such as refixation at the processus coracoideus, tenodesis in the sulcus intertubercularis, keyhole operation, in combination with an intraarticular inspection, revision, or if necessary widening of a narrow passage ("defile"). Follow-up was possible in 15 patients for an average period of 3 years after the operation, in respect of clinical, roentgenological and isokinetic findings. Results were mainly good while employing a variety of different surgical techniques; in only 3 patients the shoulder function remained restricted, painful and/or weakened. The isokinetic maximum torque was either increased on the operated side (after coracoid refixation) or reduced (after tenodesis in the sulcus). The underlying biomechanical causes are explained. Good results can be obtained in surgical treatment of the rupture of the proximal biceps tendon provided the procedure is accurately executed while taking into consideration, at the same operation stage, the associated pathology of the rotatory cuff. For biomechanical reasons, preference should be given to the operations according to Hitchcock and Bechtol in respect of refixation, and to the keyhole operation method.


[Roentgen diagnosis of post-traumatic radius torsion].

Especially the identification of rotational malunions on the distal radius is difficult by routine diagnosis. Long-time effects like a chronic loss of articular surface of the posttraumatic rotation on the distal radioulnar joint are of clinical importance. Evading expensive diagnostic methods like CT simulated rotational malunions of the radius are quantitatively investigated on the basis of routine X-ray pictures only. The geometrical relation between the rotational angle of the radius and the two-dimensional distance from the dorsal to the volar border of the radial notch is described by a simple trigonometrical function. Considering morphological individualities of the radial notch and the rotational angles of right and left radii rotational malunions below 10 degrees are discovered and their effects on the forearm skeleton are assessed.


[Clinical experience with collagenous wound dressing in severe traumatic soft tissue injuries].

We treated 34 patients during 1987-1990 with a collagen wound dressing. Eleven patients had traumatic soft tissue defects, 10 patients had 3 degrees-grade open fractures, 7 patients had infected soft tissue wounds and 6 patients had deep 2 degrees and 3 degrees-degree burns. Our clinical experience confirmed the excellent clinical experimental results of collagen wound dressings. In all cases after 4 until 6 days of treatment good granulation and vascularisation of the wound bed was obtained, so that a skin transplant could be performed, which in all cases healed primarily. Moreover, the wound dressing had a good antibacterial effect and integrated actively in the wound healing process.


[Healing of a deep skin wound using a collagen sponge as dressing in the animal experiment].

The high number of available wound dressing materials as well as the scientific reports about the topic indicates that the problem of an ideal wound dressing is not jet solved. In the last thirty years lot of scientific reports about collagen as wound covering has been published. The positive effect of collagen by his application on a wound ist well known. We investigated the effect of a collagen sponge on healing of full thickness skin wound in guinea pig. The animals were divided in two control groups and two experimental groups. In the control group there were air exposed wounds and another wounds covered with paraffin gauze. In the experimental groups were such wounds covered with natural reconstituted collagen sponge as well as wounds covered with chemically prepared collagen sponge with hexamethyldiisocyanat. The results were compared. The air exposed wounds healed in 50 days, the wounds covered with paraffin gauze healed in 48 days. By covering the wounds with collagen sponge the healing was shortened in 24 or 27 days respectively. Not only the healing time was shortened but also the quality of the wound repair by dressing the wounds with collagen sponge was enhanced.


[Ligament repair with PDS (polydioxanone) in chronic insufficiency of the fibular ligament of the upper ankle joint: experimental and clinical experiences].

From September 1988 till February 1989, 14 patients with chronic ligamentous rupture of the ankle had been operated on using PDS-plasty. Of 12 patients checked in follow-up examination (mean postoperative period 45 weeks), only two showed good or very good results. Most patients had the same signs of chronic instability as preoperatively. Two patients had been reoperated on. Intraoperatively we did not find a biological substitute along the PDS guide line. In an experiment on the rat we examined histological changes and tensile strength at appointed times. Histological data showed no biological substitute of PDS. We also found residues of PDS even after 300 days. After a short time loss of tensile strength occurred. In view of an aseptical necrosis that occurred in our experiments, we must point out the risk of foreign body granulomas.


[Anatomic reconstruction of a rare combination injury of the axis (trans-dental dislocation with hanged-man fracture) by lag screw fixation].

The patient described here suffered from a Hanged-Man-Fracture type Effendi II in combination with a densfracture type Anderson d'Alonzo II. Options of treatment are discussed, the chosen therapy with lag-screw fixation described. The functional result was perfect.


Beta-adrenergic blockers as cardioprotective agents.

The evidence supporting and describing cardioprotective effects of beta-adrenergic blocker treatment is surveyed. Details of the many studies that individually and collectively document the ability of long-term and acute beta-blocker therapy to reduce overall mortality, sudden cardiovascular death, and nonfatal reinfarction in patients surviving or experiencing a myocardial infarction are described. A discussion of the mechanisms by which beta blockers probably and theoretically achieve these benefits includes the suggestion that they may reduce plaque rupture, thus indirectly inhibiting thrombosis. It is also suggested that, in the future, further cardioprotective benefits may accrue to the use of beta blockers in conjunction with thrombolysis and of beta blockers with a duration of action sustained throughout a full 24 hours.


Divergent effects of taxol on tumor necrosis factor-alpha-mediated cytolysis of ovarian carcinoma cells.

Our objective was to study the combined effect of taxol and tumor necrosis factor-alpha on the cytolysis of human ovarian carcinoma cell lines, because taxol has been shown to be active against ovarian carcinoma and has also been shown to increase tumor necrosis factor-alpha release from macrophages. The combined effect of taxol and tumor necrosis factor-alpha on the cell lines Caov-3, SK-OV-3, NIH:OVCAR-3, and A2780, which are sensitive to the cytolytic effect of tumor necrosis factor-alpha in the presence of inhibitors of protein synthesis, was investigated with a 24-hour chromium 51 release assay. At therapeutic concentrations taxol caused a significant increase in tumor necrosis factor-alpha-mediated cytolysis of Caov-3 and A2780 (p < or = 0.05). By contrast, taxol caused a decrease in the tumor necrosis factor-alpha-mediated cytolysis of SK-OV-3 and NIH:OVCAR-3 (p < or = 0.01). These results suggest that ovarian carcinomas have a heterogeneous response to the chemotherapeutic effect of taxol.


The effect of interferon gamma on epidermal growth factor receptor expression in normal and malignant ovarian epithelial cells.

We examined the effect of interferon gamma on proliferation and epidermal growth factor receptor expression in ovarian cancer cell lines and normal ovarian epithelial cells. The tritiated thymidine incorporation assay was used to assess the effect of interferon gamma on proliferation. Scatchard analysis of anti-epidermal growth factor receptor antibody binding, and Western blotting of immunoprecipitates was used to assess the effect of interferon gamma on epidermal growth factor receptor expression. Although interferon gamma elicited 30% to 40% decreases in proliferation, epidermal growth factor receptor expression was strikingly increased in all four ovarian cancer cell lines. Scatchard analysis indicated that this increase occurred primarily at the cell surface, but total cellular receptor levels also were increased. In contrast, interferon gamma treatment of normal ovarian epithelial cells affected neither proliferation nor epidermal growth factor receptor levels. Because the up-regulation of epidermal growth factor receptors by interferon gamma appears to be confined to malignant cells, interferon gamma may facilitate immunotherapy and imaging of ovarian cancers by means of immunoconjugates directed against the epidermal growth factor receptor.


A model of the transmission of dengue fever with an evaluation of the impact of ultra-low volume (ULV) insecticide applications on dengue epidemics.

We have developed a deterministic susceptible, exposed, infectious, resistant or removed (SEIR) model of dengue fever transmission that enables us to explore the behavior of an epidemic, and to experiment with vector control practices. Populations of both host and vector are divided into compartments representing disease status (susceptible, exposed, infectious, and, for humans, resistant), and the flow between compartments is described by differential equations. Examination of the equilibrium points leads to a formulation of the basic reproduction rate (Z0) of the disease. With a base set of parameters, Z0 = 1.9 and the model realistically reproduces epidemic transmission in an immunologically naive population. Control of adult mosquitoes by ultra-low volume (ULV) aerosols is simulated by an abrupt decrease in vector densities, followed by gradual recovery of the vector population. The model indicates that ULV has little impact on disease incidence, even when multiple applications are made, although the peak of the epidemic may be delayed. Decreasing the carrying capacity of the environment for mosquitoes, and thus the basic reproduction rate of the disease, by source reduction or other means, is more effective in reducing transmission.


Arbovirus isolations from mosquitoes collected during 1988 in the Senegal River basin.

During August and September 1988, we collected adult mosquitoes from 14 locations in the Senegal River basin to search for evidence of Rift Valley fever (RVF) viral activity one year after the 1987 outbreak, which occurred along the Senegal-Mauritania border. More than 62,000 specimens representing 18 species in seven genera were collected with carbon dioxide-baited, solid-state Army miniature light traps and sheep-baited traps. Twenty virus isolations from Culex, Aedes, and Anopheles mosquitoes were recovered from six locations: Fanaye Diery (11), Bode (four), Matam (two), Diongui (one), Ndialene (one), and Ngoui (one). Species yielding viral isolates were Anopheles pharoensis (eight), Culex tritaeniorhynchus (three), Cx. univitattus gr. (three), Cx. antennatus (two), Cx. poicillipes (two), Ae. hirsutus (one), and An. gambiae (one). Viruses were identified by complement fixation, and virus and plaque-reduction neutralization testing as Ngari (Bunyavirus, Bunyaviridae) (n = 15), Babanki (Alphavirus, Togaviridae) (n = 3), Bagaza (Flavivirus, Flaviviridae) (n = 1), and Bangui (Bunyavirus-like) (n = 1). No evidence of any RVF viral activity in the Senegal River Basin was detected in the mosquitoes tested.


Bunazosin enhances receptor-mediated endocytosis of low-density lipoproteins.

The effects of bunazosin, an alpha 1-adrenergic receptor antagonist, on low-density lipoprotein (LDL) receptor activity have been studied in cultured cells. Human skin fibroblasts, swine aortic smooth muscle cells and a human hepatoma cell line (Hep G2) were used for this study. Bunazosinm, at a concentration of 5 x 10(-5) to 10(-4) M, increased 125I-LDL uptake with all of the cell lines and 125I-LDL degradation with human skin fibroblasts and swine aortic smooth muscle cells. However, in human skin fibroblasts pretreated with lipoprotein deficient serum and Hep G2 cells, the degradation of 125I-LDL was decreased by bunazosin. These results suggest that bunazosin increases LDL receptor activity.


Somatostatin inhibits vasopressin-stimulated phosphoinositide hydrolysis and influx of extracellular calcium in clonal hamster beta (HIT) cells.

Vasopressin (VP) stimulates insulin secretion and inositol phosphate (InsP) production in clonal hamster beta cells (HIT) via a cyclic AMP-independent V1-receptor-mediated signal-transduction pathway. Somatostatin (SRIF) inhibited VP-stimulated insulin secretion, and the effects of SRIF were abolished by pretreatment with pertussis toxin. The Ca(2+)-channel blockers verapamil and nifedipine also inhibited VP-stimulated insulin secretion during 20 min incubations, but verapamil was ineffective at 2 min, and the effects of SRIF and nifedipine together were not addictive. SRIF failed to inhibit further the attenuated insulin response to VP in Ca(2+)-free medium. VP-stimulated InsP production was also inhibited by SRIF in a pertussis-toxin-sensitive manner. Whereas VP-stimulated insulin secretion was almost completely inhibited by SRIF at an equimolar concentration, VP-stimulated InsP production was much less sensitive to inhibition by SRIF, even at a 100-fold excess concentration. VP increased cytosolic Ca2+ in HIT cells loaded with fura 2, the fluorescent Ca2+ indicator. The increase was biphasic, with an initial rapid spike increase followed by a prolonged second phase. Both SRIF, at a concentration which inhibited VP-stimulated insulin secretion but not InsP production, and verapamil failed to inhibit the rapid spike increase in intracellular Ca2+, but did inhibit the second phase. We conclude that VP induces biphasic changes in cytosolic Ca2+, secondary to mobilization of intracellular Ca2+ and influx of extracellular Ca2+. SRIF inhibits insulin secretion by interrupting influx of extracellular Ca2+, likely by inhibiting Gi-subunit activity. Inhibition of VP-stimulated phosphoinositide hydrolysis, which is also pertussis-toxin-sensitive, may represent an additional mechanism of action of SRIF.


Polarized distribution of neutral endopeptidase 24.11 at the cell surface of cultured human intestinal epithelial Caco-2 cells.

The human colon cancer cell line Caco-2 undergoes spontaneous enterocytic differentiation during growth, and expresses a number of brush-border-membrane-associated hydrolases typical of a differentiated phenotype. Among these are alkaline phosphatase, dipeptidyl peptidase IV and sucrase-isomaltase (sucrase, EC 3.2.1.48). Neutral endopeptidase 24.11 [EC 3.4.24.11, neprilysin (NEP)] is another abundant protease of normal enterocytes but its presence in Caco-2 cells has not been fully documented yet. In this paper, we show that Caco-2 cell extracts hydrolyse tritiated [D-Ala2Leu5]enkephalin with a Km of 180 microM, very close to the value obtained for the NEP present in the rabbit kidney (118 microM). Western-blot analysis of brush-border membranes purified from post-confluent cells revealed a protein with an apparent molecular mass of 94000 Da similar to that of the rabbit kidney NEP. The amount of enzyme in cell extracts increased as a function of the age of the culture, indicating that NEP expression is correlated with the degree of cell differentiation as is also the case for sucrase and dipeptidylpeptidase IV (DPP-IV). Binding of a radiolabelled antibody to Caco-2 cell monolayers grown on semi-permeable filters indicated that 95% of NEP molecules present at the cell surface are on the apical side. Immunocytochemical and flow cytometric analysis of intact and permeabilized cells were also used to investigate the presence of NEP and DPP-IV at the surface of Caco-2 cells. Whereas DPP-IV staining appeared to be homogeneous throughout the entire cell population, NEP-related fluorescence exhibited a bimodal distribution which indicates an uneven expression of the protein at the cell surface. Permeabilization of monolayers with saponin before staining restored a labelling pattern for NEP similar to the one obtained for DPP-IV. This suggests that although DPP-IV and NEP follow similar patterns of expression when enzymic activities are measured on whole-cell extracts, targeting of these brush-border proteins to the cell surface appears to be regulated in different ways.


Tetanus toxin action: inhibition of neurotransmitter release linked to synaptobrevin proteolysis.

Tetanus toxin is a potent neurotoxin that inhibits the release of neurotransmitters from presynaptic nerve endings. The mature toxin is composed of a heavy and a light chain that are linked via a disulfide bridge. After entry of tetanus toxin into the cytoplasm, the released light chain causes block of neurotransmitter release. Recent evidence suggests that the L-chain may act as a metalloendoprotease. Here we demonstrate that blockade of neurotransmission by tetanus toxin in isolated nerve terminals is associated with a selective proteolysis of synaptobrevin, an integral membrane protein of synaptic vesicles. No other proteins appear to be affected by tetanus toxin. In addition, recombinant light chain selectively cleaves synaptobrevin when incubated with purified synaptic vesicles. Our data suggest that cleavage of synaptobrevin is the molecular mechanism of tetanus toxin action.


A comparison of single nucleotide primer extension with mispairing PCR-RFLP in detecting a point mutation.

A recent report by Petruzzella et al. (BBRC 186, 491-497, 1992) raised a question as to whether a point mutation in the mitochondrial ND2 gene (BBRC 182, 238-246, 1992) is relevant to Alzheimer's disease. The argument was based on their inability to detect the point mutation at position 5460 in codon 331 in the DNAs extracted from 15 patients with Alzheimer's disease using mispairing PCR-RFLP. To clarify the discrepancy, we tested the DNAs reported by Petruzzella et al. for the mutation by single-nucleotide primer extension. The present work confirms our previous report and extends our finding of the point mutation in 8 of the 15 AD DNAs.


Widespread co-localization of mRNAs encoding the guanylate cyclase-coupled natriuretic peptide receptors in rat tissues.

Natriuretic peptides modulate vasorelaxation, diuresis, and natriuresis through the stimulation of cGMP production by the guanylate cyclase-coupled natriuretic peptide receptors, GC-A and GC-B. We used reverse transcription-polymerase chain reaction to determine the distribution of mRNA encoding both receptors in rat tissues. GC-A and GC-B transcripts were detected in all peripheral and neural tissues examined. Since the atrial natriuretic peptide gene is expressed in all these tissues, our widespread detection of GC-A and GC-B mRNAs now suggests that natriuretic peptides may act as endocrine and paracrine hormones as well as neurotransmitters via both GC-A and GC-B receptors.


Site-directed mutagenesis of conserved residues of Clostridium thermocellum endoglucanase CelC.

Four conserved residues of Clostridium thermocellum endoglucanase CelC were replaced by site-directed mutagenesis. Proteins mutated in His-90, Asn-139 and Glu-140 showed strongly reduced activity, in agreement with predictions of sequence alignments. Mutations in Glu-140 did not result in any detectable change in Km, or apparent size, suggesting that Glu-140 is directly involved in catalysis. The pH optimum of the proteins carrying the Glu-140/Ala and Glu140/Gln mutations was lower than that of the wild type, whereas the activity vs. pH profile of Glu-140/Asp CelC was similar to that of the wild type, suggesting that Glu-140 may act as a proton donor.


Marked association of a RFLP for the low density lipoprotein receptor gene with obesity in essential hypertensives.

RFLPs at the low density lipoprotein receptor locus (LDLR) display marked linkage disequilibrium between each other. Cross-sectional analysis of a bi-alleleic ApaLI RFLP of LDLR showed that the 9.4- and 6.6-kb alleles were present in similar frequency between a group of 84 Caucasian essential hypertensive (HT) and a group of 96 normotensive subjects whose parents each had a similar blood pressure status at age > or = 50. After subdividing HTs into lean and obese, however, the frequency of the 6.6-kb allele in the 27 HTs with BMI > or = 26 kg/m2 was 0.63, compared with 0.39 for HTs with BMI < 26 (chi 2 = 8.8; P = 0.004). The difference in genotype frequencies was even more striking (chi 2 = 23; P = 0.00008), with a virtual absence of 9.4-kb homozygotes in the obese HT group (1 vs 22). Genetic variation at LDLR (19p13.2) is thus associated with obesity in HT.


Modulation of multidrug resistance gene expression in rat hepatocytes maintained under various culture conditions.

P-glycoprotein (P-gp), the multidrug resistance gene product, is overexpressed in normal adult rat hepatocytes under standard culture conditions. We have studied the modulation of P-gp expression in this in vitro model in the presence of both epidermal growth factor and pyruvate, which favor hepatocyte growth, as well as in the presence of either dimethyl sulfoxide (DMSO) or nicotinamide, which favors maintenance of differentiated functions. P-gp overexpression, estimated by northern blotting and doxorubicin-mediated drug efflux analyses, was similarly observed during culture in both standard and proliferating conditions, while it was delayed, but not inhibited, in the presence of DMSO or nicotinamide. These results suggest that the functional P-gp overexpression occurring in rat hepatocytes when exposed to an unfamiliar environment is at least partly not related to cell proliferation or the degree of cell differentiation in vitro.


Pharmacological characterization of a beta 3-receptor agonist (BRL 37,344) and a partial agonist (CGP 12,177A) in neonatal rat liver plasma membranes.

The pharmacological properties of BRL 37,344 (sodium-4-(2'-[2-hydroxy-2- (3-chloro-phenyl)ethylamino]-propyl)phenoxyacetatesesquihydrate), a beta 3-selective agonist, and CGP 12,177A) (-)-4-(3-t-butyl amino-2-hydroxypropoxy) benzimidazole-2-one], a non-selective beta-antagonist, recently characterized as a partial beta 3-agonist in rat adipose tissue, were studied in comparison with isoproterenol, a non-selective beta-agonist, in plasma membranes prepared from the livers of newborn rats. Competition binding curves obtained with [125I]iodocyanopindolol ([125I]CYP) as ligand and isoproterenol or BRL 37,344 as competitor were characterized by the presence of a high and a low affinity binding site; the high affinity binding site was no longer detectable when guanidylimidobisphosphate (GppNHp) was present in the incubation mixture. Competition curves with CGP 12,177A were monophasic and independent of GppNHp. In the presence of 10(-7) M of the beta 2-selective antagonist ICI 118,551 [erythro-(+/-)-1-(7-methylindan-4-yloxy)-3-isopropylamino butan-2-ol], a concentration which blocks most of the beta 2-receptors, ligand binding was reduced to 32% of its maximum. Under these conditions, isoproterenol further displaced the ligand, and competition curves still displayed the high and the low affinity binding sites; BRL 37,344, however, caused no further displacement of ligand, except at the highest concentrations. This suggests that BRL 37,344 occupies only the ICI 118,551-sensitive binding sites, i.e. beta 2-receptors. Isoproterenol and BRL 37,344 both stimulated adenylate cyclase (EC 4.6.1.1) activity concentration dependently, although the stimulating effect of BRL 37,344 was about half of what was found for isoproterenol. Furthermore, BRL 37,344 inhibited concentration dependently the isoproterenol-induced stimulation of adenylate cyclase, and the inhibition was dependent on the concentration of isoproterenol. The stimulating effect of isoproterenol and BRL 37,344 on adenylate cyclase was blocked by ICI 118,551, whereas the beta 1-selective antagonist CGP 20,712A ((+/-)-(2-(3-carbamoyl-4-hydroxyphenoxy)-ethylamino)-3-[4-(1-methy l-4- trifluoromethyl-2-imidazolyl)-phenoxy]-2-propanolmethane sulphonate) was ineffective. CGP 12,177A failed to stimulate adenylate cyclase activity. From these results we suggest that BRL 37,344 acts as a beta 2-partial agonist in rat liver. The results obtained with CGP 12,177A are typical for a non-selective beta-antagonist. We therefore conclude that there is no pharmacological evidence for the presence of beta 3-receptors in livers from newborn rats.


The development of monoclonal antibodies to the human mitochondrial 60-kd heat-shock protein, and their use in studying the expression of the protein in rheumatoid arthritis.

To assess the claim that the human 60-kd heat-shock protein (HSP) is highly expressed in the joints of patients with rheumatoid arthritis (RA), but is not readily detected in normal tissues. Monoclonal antibodies were raised against the human 60-kd mitochondrial heat-shock protein (P1 protein; hsp60), and their specificity was established. They were then applied to synovial tissue. HSP was expressed similarly in normal, osteoarthritic, and RA synovium. Low levels of hsp60 were detected in synovial fluid by immunoprecipitation. Minor differences in the distribution of hsp60 in synovium from RA joints were attributable to increased cellularity and to the disorganization of the tissue architecture.


Effect of nipradilol on cardiovascular hemodynamics during exercise in angina pectoris with old myocardial infarction.

Nipradilol (3,4-dihydro-(2-hydroxy-3-isopropylamino)-propoxy-3-nitroxy-2H-1- benzopyran, K-351, CAS 81486-22-8) is a new type of beta-blocker with vasodilating action. The effect of nipradilol on hemodynamics at rest and during exercise with a multi-stage bicycle ergometer in supine position was studied in 8 male patients suffering from angina pectoris with old myocardial infarction. Nipradilol was orally given at the daily dose of 12 mg (b.i.d.) for one week, and various hemodynamic parameters were measured at rest and during exercise before and after the treatment with nipradilol. At rest, the blood pressure was almost unchanged, heart rate was significantly reduced, cardiac output tended to decrease, and the pulmonary blood pressure and left ventricular ejection fraction (EF) were almost unchanged. At peak exercise, the blood pressure tended to decline, heart rate was significantly reduced, cardiac output tended to decrease and the pulmonary blood pressure and EF increased significantly. Consequently, the antianginal effect of nipradilol is considered to be attributable to the reduction in myocardial oxygen consumption caused by a decrease in double product. It is thus suggested that nipradilol exerts its antianginal effect without adversely affecting the cardiac performance.


Effect of a new non-steroidal anti-inflammatory combination of a histamine H2 antagonist and indomethacin on gastroduodenal mucosal membrane in rat.

The new non-steroidal anti-inflammatory drug (NSAID), N-(3-[3-(piperidinyl-methyl) phenoxy] propyl)-carbamoyl-methylthio]ethyl 1-(p-chlorobenzoyl) 5-methoxy-2-methyl-3-indolyl-acetate (CP 331, CAS 127966-70-5), a compound with a structure of an ester combining indomethacin (IM) and a histamine H2 antagonist, has been reported to have anti-inflammatory, analgesic and antipyretic effects. However, the influence of CP-331 on the gastroduodenal mucosa was not fully investigated. Therefore this study was undertaken to investigate the effect of CP-331 on the gastroduodenal mucosa membrane in rats. After single oral drug administration, the UD50 value (50% ulcerogenic dose) of CP-331 calculated from the incidence rate of gastric ulcer was higher than 1000 mg/kg; that for IM was 5.2 mg/kg. Moreover it was examined whether CP-331 had a preventive effect on NSAID-induced gastric damage. The results showed that the co-administration of CP-331 10-30 mg/kg prevented significantly the acute gastric mucosal injury caused by IM administration (20 mg/kg). CP-331 with anti-inflammatory activity does not cause gastric injury, moreover, because of its preventing and therapeutic effects on the damage to gastric mucous membrane induced by IM, CP-331 might be useful in the treatment of gastropathy caused by NSAID in clinic.


Inhibition of HSV-1-specific cytotoxic T lymphocytes by recombinant-derived gp120 of HIV-1.

The ability of human immunodeficiency virus type-1 (HIV-1) and recombinant HIV-1 gp120 to prevent target cell lysis by herpes simplex virus type 1 (HSV-1)-specific cytotoxic T lymphocytes (CTL) was assessed by limiting dilution analysis. Live and inactivated HIV-1 as well as recombinant-derived gp120 all substantially inhibited HSV-1-specific CTL. Soluble CD4 antigen reversed the inhibition by gp120 when simultaneously added with gp120 to the assay. In addition, the monoclonal anti-CD4 antibody a-Leu3a mimicked the effects of gp120 in these experiments. These data suggest that the observed decrease in measurable CTL activity is caused by direct or steric hindrance of the CD4-class II major histocompatibility complex interaction between the effector and target cells.


Impairment of learning by localized injection of an N-methyl-D-aspartate receptor antagonist into the hyperstriatum ventrale of the domestic chick.

A restricted part of the domestic chick forebrain is critically involved in the learning process of imprinting. This region is the intermediate and medial part of the hyperstriatum ventrale (IMHV). The effect on imprinting of local injection of the N-methyl-D-aspartate (NMDA) receptor blocker D-amino-5-phosphonopentanoic acid (D-AP5) into the left IMHV was studied in chicks in which the right IMHV had been lesioned. The left IMHV is essential for imprinting when chicks have been lesioned in this way. Injection of approximately 0.7 nmol D-AP5 into the left IMHV significantly impaired imprinting. Injection of approximately 0.2 nmol D-AP5 into the left IMHV, or of approximately 0.7 nmol D-AP5 into the left hyperstriatum accessorium, was without significant effect on imprinting. These results suggest that NMDA receptors in the left IMHV may play an important part in this learning process.


Subthalamic nucleotomy alleviates parkinsonism in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-exposed primate.

Research into the neural mechanisms underlying the symptoms of parkinsonism utilizing the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-exposed primate model have shown that the subthalamic nucleus (STN) occupies a central role. As a logical development of this theory, we have studied the effects of thermocoagulative lesions of the STN in the primate model. Such lesions can cause remarkable symptom reversal in the experimental primate model.


Large diurnal variation in CD4 cell count and T-cell function among drug users: implications for clinical practice and epidemiological studies.

To measure diurnal variation in the CD4 cell count and T-cell reactivity of drug users. A prospective epidemiological study among HIV-infected and non-infected drug users attending the Municipal Health Service of Amsterdam, The Netherlands. Eleven HIV-infected and seven non-infected drug users. CD4 cell counts and T-cell reactivity three times a day. T-cell subsets and T-cell reactivity were determined from blinded samples within 2 hours. The number of CD4 cells increased by 130 x 10(6)/l (P < 0.05) in HIV-infected intravenous drug users over 8 hours. Following stimulation with anti-CD3 monoclonal antibodies, the T-cell reactivity of HIV-infected drug users rose from 118 to 221 c.p.m. (P < 0.01) over 8 hours. CD4 cell counts of the total study population increased by 37% and T-cell reactivity by 93%. The increase in the number of CD4 cells was more marked among active drug users than among drug users who had not used drugs recently. Variation in the CD4 cell count and in T-cell reactivity is large among drug users.


A novel coculture system for evaluating anti-HIV drugs.

To develop a useful system for evaluating novel anti-HIV drugs. The activity of most antiviral compounds in cell-free HIV infection systems has been evaluated. However, the inhibitory effects on both the process of HIV induction and viral dissemination to uninfected cells have not been fully investigated. We have therefore developed a new cocultivation system using chronically HIV-infected monocytes and CD4+ T-lymphocytes in the presence of tumor necrosis factor (TNF). We designed a cocultivation system using flow cytometry with U1 cells and Molt-4 cells in the presence of TNF. The antiviral activities of several compounds in the cocultivation system and other assay systems were compared. Only pradimicin A and glycyrrhizin showed strong inhibitory activity in the cocultivation system in the presence of TNF, whereas dextran sulfate, curdlan sulfate and N-acetylcysteine exhibited moderate or weak inhibitory activity in the system. 3'-azido-2',3'-dideoxythymidine and 2',3'-dideoxyadenosine were completely ineffective in the system. These results support the suggestion that our cocultivation system includes HIV induction in chronically infected monocytes, and the resulting cell-to-cell infection between HIV-infected monocytes and Molt-4 cells or Molt-4 cells and their HIV-converted counterparts. Our new cocultivation system may constitute a useful tool in the identification of novel anti-HIV compounds.


Effect of ethanol on ascorbate release in the nucleus accumbens and striatum of freely moving rats.

An in vivo voltammetry technique was used to monitor the extracellular ascorbate (AA) concentration in the nucleus accumbens and striatum of unanesthetized, freely moving rats. A single injection of ethanol, 1.0 g/kg intraperitoneally (IP), induced a significant increase in extracellular AA concentration in both the nucleus accumbens and striatum. This effect was dose dependent within a dose range from 0.5-2.0 g/kg. 4-Methylpyrazole (50 mg/kg, IP), which inhibits alcoholdehydrogenase, could not prevent the increase in AA concentration, evoked by ethanol. Furthermore, systemic administration of acetaldehyde (20 mg/kg, IP), the main metabolite of ethanol, did not have any effect on the level of AA in the nucleus accumbens or striatum. These results show that ethanol can alter the brain extracellular AA levels and that this effect seems to be attributed to ethanol itself and not to acetaldehyde. Consequently, these results indicate that a role for AA in the action of ethanol in the brain should be considered.


Methods for detecting early signs of AIDS dementia complex in asymptomatic HIV-1-infected subjects.

To determine the optimal diagnostic procedures for identifying early signs of AIDS dementia complex (ADC) in asymptomatic HIV-1-infected individuals, in order to prevent further cognitive function impairment by early treatment. Study patients had been referred electively and consecutively to hospital; all had been referred for the first time and gave informed consent. Inclusion criteria were (1) lack of history and/or symptoms of psychosis and neurological disorders; (2) lack of active viral, protozoan or fungal pathology; (3) abstinence from heroin and/or cocaine for at least 6 months before baseline evaluation. Subjects were seen at the L. Spallanzani Hospital for Infectious Diseases, Rome, Italy between March 1989 and March 1991. Eighty-two asymptomatic HIV-1-infected subjects: 41 drug users, 27 homosexuals and 14 heterosexuals. All subjects were evaluated using Wechsler-Bellevue I, Benton C form and Bender tests. Thirty-nine subjects underwent single-photon emission computed tomography (SPECT) and 12 magnetic resonance imaging (MRI). The immunological status of each subject was determined. On psychometric testing, 23 out of the 82 (28%) asymptomatic subjects had a mental decay percentage (MD%) > or = 20%. Cerebral perfusion abnormalities were detected in 31 out of 39 (79.48%) subjects who underwent SPECT; MRI abnormalities were observed in seven out of 12 (58%) subjects. Twelve out of 23 subjects with MD% > or = 20, 15 out of 29 subjects with SPECT abnormalities and four out of seven patients with MRI abnormalities had total CD4+ lymphocyte counts > or = 500 x 10(6)/l. The high incidence of abnormal SPECT and of MD% > or = 20 in asymptomatic HIV-1-infected patients, and the lack of correlation between immunological status and degree of mental decay, SPECT and MRI abnormalities raise many questions about subclinical HIV-1 neurological disease.


Relationship between herpes simplex virus ulceration and CD4+ cell counts in patients with HIV infection.

To establish the incidence of herpes simplex virus (HSV) ulceration in relation to CD4+ cell counts in HIV-infected patients. Swabs were taken from all ulcerated lesions in HIV-infected patients and cultured for HSV. CD4+ cell counts were performed at regular intervals. The HIV unit at a London teaching hospital (the Royal Free Hospital, London, UK). All HIV-infected patients (n = 500) attending the HIV unit. Two hundred and twenty-three swabs were obtained from 118 patients; 83 (37.2%) swabs from 62 (52.5%) patients were positive for HSV. Of 96 swabs taken from patients with CD4+ cell counts < 50 x 10(6)/l, 56 (58.3%) were positive for HSV, compared with 27 of 127 (21.2%) swabs from patients with higher CD4+ cell counts (P < 0.0001). Of patients with CD4+ cell counts < 50 x 10(6)/l, 37 of 47 (78.7%) had positive cultures compared with 25 of 71 (35.2%) of patients with higher counts (P < 0.0001). This trend was observed with swabs from all body sites; sufficient samples were available from oral and perianal lesions to demonstrate statistical significance (P < 0.0001 and P = 0.007, respectively). These results show a sharp rise in the incidence of HSV with CD4+ cell counts < 50 x 10(6)/l and thus provide important data for the design of studies of anti-HSV prophylaxis. Furthermore, since nearly 60% of all ulcers in patients with such low CD4+ counts are HSV-positive, we suggest appropriate empirical therapy on presentation.


Maintenance of CD4+ cells by thymopentin in asymptomatic HIV-infected subjects: results of a double-blind, placebo-controlled study.

To assess the efficacy and safety of thymopentin in HIV-infected patients who had not yet developed AIDS. Patients were stratified into asymptomatic or symptomatic groups and randomized to receive either thymopentin (50 mg) or placebo, subcutaneously, double-blind for 24 or 52 weeks, three times a week. Patients were enrolled at three sites (two hospital clinics and one private practice). Of 91 HIV-seropositive patients (52 asymptomatic and 39 symptomatic) from whom HIV could be isolated from peripheral blood, 45 were enrolled for 24 weeks and 46 for 52 weeks of double-blind evaluation. Virological, immunological and clinical evaluations were performed before and during treatment. Thymopentin-treated asymptomatic patients had more CD4+ cells, as demonstrated by a greater area under the percentage CD4+ cells curve (P = 0.03) and a shorter median time to a 20% increase in percentage of CD4+ cells (P = 0.04) in the first 24 weeks, with similar trends in the 52-week study. By 24 weeks no asymptomatic thymopentin-treated and two placebo-treated patients (9.1%, Kaplan-Meier estimate) had progressed to constitutional symptoms (P = 0.12; two-tailed Wilcoxon-Gehan test), with only one further progression in a placebo-treated patient in the subset followed for 52 weeks. Symptomatic patients receiving thymopentin or placebo were similar in both CD4+ cell levels and disease progression (two progressions to AIDS in each group). No serious adverse effects attributable to thymopentin were observed. These results, if confirmed, indicate that thymopentin, by maintaining CD4+ cells, could slow or arrest immune decline and consequent disease progression at the asymptomatic stage of HIV infection.


Differences in laboratory values in HIV infection by sex, race, and risk group.

To determine differences in CD4+ and CD8+ lymphocyte values, beta 2-microglobulin (beta 2M), and HIV p24 antigenemia by sex and race among HIV-seropositive and HIV-seronegative injecting drug users (IDU), and to compare these values with those in homosexual men of equivalent status. Baseline values from a cohort of 206 HIV-seropositive and 173 HIV-seronegative IDU were compared with values from a cohort of 288 HIV-seropositive homosexual men and 176 HIV-seronegative controls, who were prospectively followed at 6-month intervals, to examine differences in laboratory values in HIV-infected individuals by sex, race, and risk group. Among HIV-seropositives, we compared white and black IDU only (n = 167), and white male IDU (n = 38) with white homosexual men (n = 256). Laboratory values from the cohort of homosexual men at 24, 36 and 48 months of follow-up were compared with IDU values. HIV-infected female IDU had significantly higher CD4+ lymphocyte counts (P < 0.03) and percentages of CD4+ lymphocytes (P < 0.004) than male IDU, resulting in higher CD4:CD8 ratios (P < 0.002). White IDU had significantly higher serum beta 2M levels than black IDU (P < 0.02). Black female IDU were much less likely to be HIV p24-antigenemic (1%) than all other groups (P < 0.005). Compared with homosexual men, male IDU had significantly elevated beta 2M levels (0.58 mg/l higher). When controlled for CD4+ lymphocyte values as a surrogate for length of time HIV-infected, beta 2M and HIV p24 antigenemia differences persisted. These differences should be considered when HIV p24 antigen, CD4+ lymphocyte counts and beta 2M levels are used as surrogate markers in clinical trials and management of HIV disease.


Prognostic value of an elevated CD8 lymphocyte count in HIV infection. Results of a prospective study of 152 asymptomatic HIV-positive individuals.

To evaluate the prognostic value of an elevated CD8 lymphocyte count in the early stages of HIV infection. A prospective study ongoing since January 1986. One hundred and fifty-two asymptomatic HIV-positive individuals with a CD4 lymphocyte count > 400 x 10(6)/l at enrollment were included. Disease progression was defined as a CD4 count < 200 x 10(6)/l. During the follow-up period, CD4 count decreased in 33 individuals; CD8 count increased to > 1500 x 10(6)/l in 38 individuals and doubled in 35. The risk of a decreasing CD4 count was estimated to be 1.7-fold higher, although not significantly so, after the elevation of the CD8 count to > 1500 x 10(6)/l than before or in the absence of such an increase. However, this predictive value disappeared when five baseline parameters found to predict the outcome (neopterin, beta 2-microglobulin, p24 antigen, anti-p18 antibody and immunoglobulin A) were adjusted. Elevated CD8 count appears to be a weak marker for disease progression.


Expression of the fragile-X in the "premutated"/"non-imprinted" state.

Data about the expression of the fragile site at Xq27.3 from 74 daughters of normal transmitting males (NTMs) were collected from 7 different genetic centers. The majority (85.1%) of these obligate female carriers did not show any cytogenetic expression of fra-X. The remaining 14.9% of these females had frequencies below 3%. In cases with a frequency below 3% of fra-X, a "premutated"/"non imprinted" state of a female carrier should be considered. The results of this collaborative study are in accordance with data from DNA studies taking the premutation model into account.


Enzyme-linked immunosorbent assay for determination of antibodies to Vibrio cholerae toxin-coregulated pili.

An ELISA for determination of antibodies to V. cholerae TCP was developed. Since purified TCP preparations contained detectable amounts of LPS (as shown by ELISA and immunoelectron microscopy with anti-LPS polyclonal serum), a capture ELISA was used. In this test the plate was coated with anti-TCP monoclonal antibody followed by incubation with TCP fimbriae. By this procedure no LPS bound to the solid phase as shown by the loss of reactivity with anti-LPS serum. The capture ELISA allowed sensitive and specific determination of TCP antibodies in sera of rabbits immunized with classical but not El Tor V. cholerae strains. There was good agreement between results in the TCP ELISA and reactivity with the TcpA band in immunoblot analyses when antisera raised against classical and El Tor vibrios were studied.


Expression of proliferative cell nuclear antigen (PCNA) in urinary bladder carcinoma. Evaluation of antigen retrieval methods.

Proliferative cell nuclear antigen (PCNA) expression was analyzed in formalin-fixed and paraffin-embedded specimens from patients with urinary bladder cancer using three different anti-PCNA monoclonal antibodies. In 20 recent cases a positive correlation was found between the extent and intensity of PCNA staining and grade of malignancy. In 95 specimens, three to six years old, extensive positive staining was detected in 15 and 23% of grade 2B and 3-4 tumors, respectively. No equivalent staining was found in the grade 1 and 2A tumors. In material more than six years old, a remarkably weak staining was observed regardless of grade. Similarly, in a test of archival material of tonsils a very weak immuno-reactivity was found as compared with fresh material. However, antigen retrieval by microwave heating of the tissue sections was possible in the majority of all cases, and the difference in extent and intensity of the staining between low and high grade tumors remained.


CD45 phosphotyrosine phosphatase and p56lck protein tyrosine kinase: a functional complex crucial in T cell signal transduction.

Tyrosine phosphorylation of several intracellular proteins is observed very early during T cell activation. p56lck, a non-receptor src-like protein tyrosine kinase (PTK) which is associated with the intracellular domains of CD4 and CD8 co-receptors, has been implicated in these early signal transduction events. Furthermore, recent experiments indicate that the receptor phosphotyrosine phosphatase, CD45, might be important in the regulation of p56lck PTK activity and that its expression is required for the generation of second messenger molecules following TCR triggering. Here, using co-capping experiments and double indirect immunofluorescence microscopy in functional human T lymphocytes, a specific co-distribution of a significant fraction of p56lck with CD45, but not with several other cell surface proteins, has been revealed. This is the first demonstration of a physical interaction between a receptor phosphotyrosine phosphatase and a PTK under physiologically relevant conditions. In addition, after antibody-induced capping of CD4, both a co-localization of p56lck and CD4, and concomitantly a significant increase in intracellular phosphotyrosine at the sites of CD4 caps were observed. In strong contrast to these results, co-clustering of CD4 with CD45 did not result in any detectable intracellular phosphotyrosine at the cap sites. These data indicate that CD45 can act on CD4-associated phosphoproteins in viable human T lymphocytes. Further, this provides evidence that p56lck PTK is a substrate of CD45 phosphotyrosine phosphatase in vivo and thereby supports the idea that CD45 is an early regulator of T cell activation involved in the modulation of the coupling of receptor-triggered events to intracellular signalling pathways.


Analysis of the steady-state and initial rate of doxorubicin efflux from a series of multidrug-resistant cells expressing different levels of P-glycoprotein.

Continuous monitoring of fluorescence (CMF) has been used to examine doxorubicin efflux from intact human myeloma cells. The time resolution of these measurements has enabled detailed comparison of the initial rates of efflux for the drug-sensitive myeloma line RPMI 8226 and a series of sequentially derived multidrug-resistant (MDR) lines expressing different amounts of human MDR protein (P-glycoprotein). Cells that are 3-, 10-, 60-, or 120-fold resistant to doxorubicin export approximately 10, 20, 30, or 33% more doxorubicin than the parental sensitive cells, respectively, when all are preloaded to the same level of total intracellular drug. Remarkably, however, when cells are loaded to the same level of exchangeable drug the initial rates of efflux are found to be virtually identical. This agreement between rates is apparently not dependent on the drug concentration. Approximately 50% of the increase in the steady-state level of doxorubicin efflux for the resistant cells is abolished upon glucose starvation. However, surprisingly, the apparent initial rates of efflux from the treated and untreated cells are found to be virtually the same. Pretreatment of the resistant cells with verapamil reduces the steady-state level of efflux but increases the apparent initial rate at some concentrations. Conversely, vincristine does not alter steady state but slows the initial rate of efflux from both sensitive and resistant cells by approximately the same extent. Finally, quite interestingly, a nearly linear relationship between pHi and relative steady state of efflux is found for the series of cell lines. These data are interpreted in terms of existing models for MDR.


Failure of CAPD patients to respond to an oral iron absorption test.

CAPD patients require supplemental iron to maintain a response to erythropoietin. Because of limited availability of parenteral iron dextran, oral iron must be used. However, oral iron may not be effective in most dialysis patients. To determine if oral iron is well absorbed, a modified oral iron absorption or tolerance test was performed in CAPD patients using two oral iron preparations. Serum irons were measured at baseline in a fasting state and repeated two hours after the ingestion of 325 mgs ferrous sulfate in five CAPD patients. In addition, eight patients had serum irons determined before and two hours after taking liquid oral ferrous fumarate in capsule form. Healthy controls were compared with each group. All five patients who received ferrous sulfate had borderline to low normal serum iron and iron stores. Average increase in serum irons was only 19 mcg/dl in patients compared to 52 mcg/dl in controls. Patients receiving ferrous fumarate rose only 14 mcg/dl compared to 60 mcg/dl in controls. We conclude that oral iron is poorly absorbed in most CAPD patients and that the oral iron absorption test may be helpful in identifying patients who are effective iron absorbers. Unfortunately, until parenteral iron dextran is readily available, oral iron therapy is the only alternative for iron supplement. The oral iron absorption test may predict who will respond to oral iron in the long-term.


Single center success with a high risk peritoneal dialysis population.

A large end stage renal failure population treated by chronic ambulatory peritoneal dialysis (CAPD) was examined for rates of infection, CAPD modality failure and patient survival (N = 347). Nearly half were considered high risk for survival for reasons of age (39% older than 60 years), diabetes mellitus (33%), hemodialysis access failure (10%), poor cardiopulmonary reserve (16%) or technical challenges (30% had morbid obesity, history of abdominal aortic aneurysm repair or multiple abdominal surgeries). Hence, CAPD was often initiated by default rather than choice in the 347 patients studied (mean age: 51 +/- 17 years). Infections greatly outnumbered technical failures as grounds for cessation of CAPD. Over 5521 patient-months, 51% of patients developed infection with peritonitis predominating (80%) when compared to exit site infections (20%). The frequency of infections was 1.9 mean episodes per patient; however, 55% of these patients had only one episode of peritonitis. A rate of 0.75 infections per patient per year was seen with an average interval of 16 months between infections. Technique and patient survival rates at 4 years were 50% and 61% respectively. High risk status does not preclude successful CAPD and should not preclude its implementation.


Routine measurement of hydrostatic intraperitoneal pressure.

A simple, non-invasive and well-tolerated technique for routine measurement of intraperitoneal hydrostatic pressure (IPP) in patients treated with peritoneal dialysis (PD) is presented. The height of the dialysis fluid in the PD line was measured, under atmospheric pressure, before drainage and during inspiration (IPPinsp) and expiration (IPPexp), taking the axillary line as the reference point of the resting subject in strict supine position. Normal values were established for a population of 18 patients treated with PD for 19.8 +/- 20.9 months under clinical and biological stable conditions. For an intraperitoneal volume of 2,820 +/- 419 ml, IPPinsp = 14 +/- 2 cmH2O; IPPexp = 12 +/- 2 cmH2O; IPP mean (defined as (IPPinsp+IPPexp)/2) = 13 +/- 2 cmH2O; IPP (defined as IPPinsp - IPPexp) = 2 +/- 2 cmH2O. IPP could not predict mechanical complications (hernia, hemorrhoids, dialysis fluid leakage) but the maximal IPPexp clinically tolerated was 20 cmH2O.


Chondroitin sulphate and peritoneal permeability.

We studied the effect of chronic intraperitoneal (ip) infusion of saline supplemented with the glycosaminoglycan-chondroitin sulphate 0.1% on the permeability and peroxidation of the peritoneal membrane in rats and compared this with the effect of saline infusion alone. Animals treated with chondroitin sulphate had a higher net ultrafiltration (uf), a slower glucose absorption from the dialysate and less trans-peritoneal loss of proteins. Chronic ip infusion of chondroitin sulphate reduced peroxidation of the peritoneum. These observations suggest that chondroitin may effect the peritoneal interstitium-an important barrier of fluid and solutes transport.


Low protein catabolic rate and serum albumin correlate with increased mortality and abdominal complications in peritoneal dialysis patients.

We retrospectively reviewed 167 consecutive peritoneal dialysis patients with regard to serum albumin (Alb), mortality and abdominal complications. In addition, 25 patients were studied with serial measurements of urea kinetics. The patients were divided into four groups based on their dialysis index (DI) and normalized protein catabolic rate (NPCR) (Table I). 12/167 patients were identified with abdominal catastrophes. Before these complications occurred, the M Alb in this group was 2.67 + 0.24 (compared to age, sex and disease matched controls of 3.55 + .11 P < .05). Six of these patients died from abdominal complications. In the 26 patients with serial urea kinetic studies, 4/11 patients in group IV died (low NPCR and low DI) (P < .05 compared to Group I, II or III). We conclude that urea kinetic modeling is predictive of outcome in those patients with presumed poor nutrition and inadequate dialysis and that abdominal catastrophes are more common in those patients with poor nutrition. Prospective interventional studies should be designed in an attempt to improve the poor outcome in this group of patients.


Remarkable improvement of activity by CAPD in a hemodialysis patient with a pseudotumor of the craniocervical junction.

Pseudotumor of the craniocervical junction and destructive spondyloarthropathy (DSA) are the most serious forms of dialysis amyloidosis (DAA). Pain and paralysis due to these lesions significantly impair activity of a patients' daily life (ADL). CAPD improved ADL of a 54 year-old male patient complicated with various forms of DAA after 17 years of hemodialysis (HD) treatment. He was first diagnosed as having carpal tunnel syndrome 12 years after initiation of hemodialysis followed by dialysis shoulders(12 years), trigger fingers(12 years), bone cysts(15 years), tendon ruptures(17 years), DSA and a pseudotumor of the craniocervical junction(17 years). Magnetic resonance imaging (MRI) taken in May 1989 revealed a pseudotumor of the craniocervical junction, which was 30 mm in diameter, located in front of partially destroyed C1 and C2. Neck pain and muscle weakness rendered him bed ridden. Six months after switching to CAPD with administration of prednisolone, neck pain disappeared. He recovered the muscle power by physical rehabilitation. At last it became possible for him to perform the CAPD procedure by himself and drive a car to the hospital as an out patient. In such cases of pseudotumors of the craniocervical junction, CAPD is one of the best methods for relieving the pain and muscle weakness.


Adequacy of peritoneal dialysis: a review of quantitative and qualitative approaches.

This paper reviews the qualitative and quantitative approaches to assessing the adequacy of peritoneal dialysis. The quantitative measures reviewed include the KT/V urea index, the dialysis index, the weekly creatinine clearance, and the creatinine efficiency number. Studies that support as well as refute these measures are reviewed briefly. Many of these studies are retrospective analyses of longitudinal data in small numbers of patients or prospective cross-sectional studies. A prospective, longitudinal study involving large numbers of patients is required to resolve some of the controversies regarding the adequacy of peritoneal dialysis.


Comparison of the efficacy cost and complication rate of APD and CAPD as long-term outpatient treatments for renal failure.

We compared 10 patients treated with overnight APD in their homes with a parallel group of 30 patients having CAPD (Freeline II) over two years 1990 and 1991. Our aim was to discover if APD was an efficient and cost effective alternative to CAPD. The average amount of dialysate used per day in APD patients was 11 litres (range 9 to 14 litres) compared to 6.8 litres (range 6 to 10 litres) for CAPD. The average plasma creatinine was 920 umol/L, plasma urea of 21 mmol/L on APD and 825 umol/L and 24 mmol/L respectively on CAPD. In 1990 there were 2 incidences of peritonitis (2 in 1991) in the APD patients compared to 24 incidences (24 in 1991) in the CAPD patients with 6 recurrences (5 in 1991) and 19 exist site infections (24 in 1991). The average fluid costs plus disposables were comparable. However the cost of treating complications per patient for APD was for 1990 32 pounds (108 pounds in 1991) and for CAPD 832 pounds (1308 pounds in 1991). All the APD patients who had previously experienced CAPD preferred this treatment for its convenience and social acceptability. APD is a cost-effective alternative to CAPD and has advantages in some patients.


Quantitative and qualitative changes of serum albumin in CAPD patients.

This study was conducted to assess quantitative and qualitative changes in serum albumin in CAPD patients. For twenty-six CAPD patients as well as age-, sex- and dialysis history-matched HD patients, biochemical and physiological parameters including urea kinetics were determined. Albumin was qualitatively evaluated by HPLC. The CAPD patients showed significant decreases in serum albumin and the reduced form of albumin accompanied by a lower protein catabolic rate(PCR) compared to the HD patients. Thirty five % of CAPD patients showed mild to moderate hypoalbuminemia, associated with a higher incidence of peritonitis and longer hospital stay. Patients with hypoalbuminemia had less of the reduced form of albumin. A weak positive correlation was found between serum albumin concentration and KT/V, and PCR. Thus, in CAPD patients, there occur quantitative and qualitative changes in serum albumin. Hypoalbuminemia may be a risk factor for peritonitis and is due in part to insufficient dialysis and protein intake. Intermolecular change in albumin may possibly be due to uremia per se.


Urea and creatinine generation and removal in a pregnant patient receiving peritoneal dialysis.

Peritoneal dialysis is the preferred form of dialysis during pregnancy because it is continuous and lacks the wide variation in chemistries, weight and blood pressure, and avoids the use of anticoagulation necessary during hemodialysis. This is a case report of a successful vaginal delivery of a 35 week healthy baby boy to a patient with end stage renal disease receiving peritoneal dialysis. Approximately one year after starting peritoneal dialysis for end stage renal disease of unknown etiology, this patient was noted to be pregnant during a transplant evaluation. BUN and creatinine generation increased with pregnancy. In order to keep the plasma BUN less than 50 mg/dl and creatinine less than 5 mg/dl, BUN and creatinine removal were increased by increasing the liters of dialysate from 8 liters to 16 liters per day. The peritoneal volume decreased from an initial 2 liters to 0.8 liter per exchange. The frequency of exchange increased. This was accomplished at home with a cycler so the patient was able to continue self care and maintain a quality of life. Peritoneal equilibration test during pregnancy did not change.


Comparison of survival in CAPD and hemodialysis: a multicenter study.

We studied 1,622 patients who started regular dialysis treatment between 1985 and 1989 in 19 centers from the Italian CAPD Study Group. There were 962 pts (59%) and on HD; 660 pts (41%) on CAPD. CAPD pts were older and had more risk factors at the start than HD pts (p < 0.0001). Overall patient survival was not statistically different between CAPD and HD at 6 years (42% CAPD; 54% HD). Multivariate analysis (Cox's model) on all population revealed that age and pretreatment risk factors had a statistically significant impact on patient survival (p < 0.0001), but not the type of dialytic treatment (CAPD or HD). When multivariate analysis was applied separately by treatment modalities, in HD group age and risk factors had the same negative influence on survival (p < 0.0001) while in CAPD group the influence of age on survival was less significant (p 0.025). This multicenter study carried out with appropriate statistical methods in a large number of pts demonstrates that patients' survival at 6 years is not different on CAPD and HD (despite the worse patient selection on CAPD) and can be even better on CAPD for aged patients.


Non-renal indications for peritoneal dialysis.

Peritoneal dialysis is rarely indicated for conditions other than end-stage renal failure. Patients with refractory congestive cardiac failure, who are awaiting cardiac transplantation or have potentially reversible cardiac disease, appear to benefit from CAPD. The prognosis of patients with fulminant hepatic failure or severe acute pancreatitis has not yet been shown to improve with the addition of peritoneal dialysis to standard supportive treatment. Isolated reports have suggested that patients with hypothermia, hyperthermia, dialysis-associated ascites and drug poisonings may be treated successfully with peritoneal dialysis. The above indications are encountered infrequently and renal failure remains the only major indication for commencing patients on peritoneal dialysis.


Renal malignancy in peritoneal dialysis patients with acquired cystic kidney disease.

A known complication of long-term hemodialysis, acquired cystic kidney disease (ACKD) has been reported infrequently in association with chronic ambulatory peritoneal dialysis (CAPD). The duration of end stage renal failure (ESRF) is thought to correlate with the development of ACKD. Renal cell carcinoma has been reported in 4-10% of patients with ACKD. Two patients on CAPD for more than 6 years without prior hemodialysis treatment developed renal malignancy in the setting of ACKD. Flank and abdominal pain was the presenting symptom in both patients neither of whom had hematuria. Renal ultrasound detected cystic lesions consistent with ACKD; malignant masses were ultimately identified by CT scan. Both patients underwent flank radical nephrectomy, resumed CAPD early in the postoperative period and continue on CAPD 9 and 4 months after surgery. One patient has since developed hepatic metastasis. ACKD is an important risk factor for the development of renal cell carcinoma not only in maintenance hemodialysis patients but also in the CAPD population. A high index of suspicion and serial ultrasound screening for ACKD is warranted in patients with long-term dialysis-dependence.


Safety of intraperitoneal calcium therapy in a rodent model.

Hypocalcemia can be a significant problem for the patient with end stage renal disease (ESRD). Although oral calcium supplementation and activated vitamin D therapy may be successful in normalizing serum calcium levels, occasional peritoneal dialysis patients have persistent and clinically significant hypocalcemia. Several researchers have successfully utilized intraperitoneal calcium therapy (ICT) for the treatment of this abnormality. In order to evaluate whether high calcium dialysate is well tolerated, we developed a model system of ICT in Sprague Dawley rats. These rats received intraperitoneal infusion with either normal or high calcium peritoneal dialysate. Studies in this experimental rodent model showed no evidence of adverse effects of high calcium dialysate when used for up to 71 days, except for unexplained weight loss in the high calcium group. ICT can be an important adjunct in the treatment of hypocalcemia seen in patients on peritoneal dialysis. This preliminary animal study supports its clinical use. However further long term studies in animal models will be necessary to establish the long term safety of this therapy.


Hearing thresholds in CAPD patients.

Ultra high frequency (UHF, 10-20 kHz) and conventional audiometric thresholds (0,25-8 kHz) were obtained from 42 stable CAPD patients. Twenty-one (50%) and 11 (25%) of the patients had UHF and conventional hearing loss respectively, when compared to age related control data. This was unrelated to length of chronic renal failure and number of treatments with ototoxic drugs. Sixteen of these patients were monitored audiometrically using UHF during a course of vancomycin therapy for peritonitis. There was no significant change in hearing thresholds. In conclusion there is high incidence of hearing loss in CAPD patients which is unrelated to ototoxic drugs.


Effects of amino acid dialysate on appetite in CAPD patients.

The use of amino acid (AA) dialysate in CAPD patients may have theoretical disadvantages, since protein ingestion is known to suppress food intake in humans disproportionately to its energy value. Therefore we measured subjective appetite and food intake of CAPD patients in a cross-over study of 16 subjects (age 22-75 years, BMI 19-31, > 3 months on CAPD, non-diabetic and not protein malnourished). They received, in random order, either 4 weeks of dextrose only (their usual treatment), or one AA (1%) exchange replacing the first dextrose exchange each day. Subjective measurements of food intake (3 day food record) and quantitative measurements of lunch time food intake were obtained during a morning dextrose exchange after 28 days of each regimen. Except for a reduction in feelings of fullness during the AA treatment, there were no effects on feelings of hunger/satiety, food appeal, lunch-time food intake, or on 3-day food intake. We conclude that the use of a daily AA (1%) dialysate for 4 weeks does not affect subjective appetite or food intake of CAPD patients. There may even be a beneficial effect as the feeling of fullness decreased with the AA treatment.


Improved nutritional follow-up of peritoneal dialysis patients with bioelectrical impedance.

A threat to survival in renal failure, malnutrition in continuous ambulatory peritoneal dialysis patients (CAPD) is often occult as CAPD patients often gain weight masking actual protein malnutrition. Bioelectrical impedance (BEI) accurately assesses body composition in CAPD patients and uncovers subtle changes in lean body mass (LBM) that escape indirect anthropometric detection. Segregating parameters of body composition is crucial to nutritional management of CAPD patients in whom fat may account for overall weight gain. While both skin-fold methods and BEI correctly distinguished thin and overweight patients in terms of fat mass, only BEI accurately segregated these patients by LBM (P = 0.007). Serial weights of 39 CAPD patients followed longitudinally for three or more months did not correlate with BEI-measured changes in LBM. LBM was lost in 49% of patients as determined by BEI, while serial weights detected a loss of LBM in 36% of these patients. Strikingly, by serial weights, 64% of patients demonstrated weight gain; however, in 24% of these an actual loss of LBM was demonstrated by BEI. BEI provides specific quantitation of LBM in CAPD patients with changing body habitus and unrecognized nutritional derangement.


Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-I (PAI-I) levels in plasma and peritoneal effluent in patients on CAPD.

The formation of fibrin on peritoneal surface has been related to the appearance of adhesions both, in surgical and CAPD patients. It is known that mesothelial cells have fibrinolytic activity related with t-PA production. We studied plasma and overnight peritoneal effluent (OPE) from 20 CAPD stable patients. Antigenic PAI and t-PA were determined. These values and its correspondent peritoneal saturation indexes were compared to urea and creatinine MTCs, peritonitis incidence, UF capacity, protein losses, Pi, Ca, Na, CO2t, urea and creatinine OPE levels. Plasma t-PA 6.64 +/- 4.68 (2.4-20); Plasma PAI-I 24.8 +/- 17.1 (p < 0.001 in respect to controls) (4-62); OPEt-PA 1.46 +/- 0.95 (0.4-4.6); OPE PAI-I 7.3 +/- 5.6 (0-20.4). Peritoneal saturation ratios were for t-PA 29.6 +/- 21% (6-65) and for PAI-I 34 +/- 32% (7-132). In conclusion our data do not support strong relationship between peritoneal t-PA/PAI system and the functional characteristics of the peritoneal membrane although plasma PAI-I, after an increase in patients at early stages on CAPD, shows a tendency to decrease over time and frequent peritonitis. The values of peritoneal saturation ratios for t-PA/PAI are higher than expected for their molecular weight, which suggests local production. An elevated plasma t-PA levels has been found in older patients.


Key factors to improve survival of elderly patients on CAPD.

The adequacy of dialysis is a primary concern when caring for patients undergoing CAPD. It is also important to analyze the key factors, which will reflect on the prognosis of elderly patients on CAPD. In this study, 60 CAPD patients were examined. The peritoneal and residual renal clearance of these patients were calculated every six months. These patients were divided into three groups (G-1 = poor, G-2 = fairly good, G-3 = good) according to their clinical parameter scores using a s-albumin,Ht,LBW, and s-cholesterol level. This study showed that the values of (KT/V) urea and Curea showed no statistical differences. These results therefore indicate that the major reason for the poor outcome in elderly patients is due to low dietary protein intake.


Increased total body fat during PD treatment.

Sufficient nutritional intake is important to adjust the increased catabolic rate in uremic patients during dialysis treatment. Increased glucose absorption during PD treatment may, however, interfere with the amount of muscle- and fat-mass in the body. We have therefore studied the amount of total body fat composition in 8 male PD patients (treatment period 79 months, range 3-23 before and 165.5 months, range 8-35.5 after the study). Food intake was recorded for 7 days twice in four patients with an interval of 6-8 months. Total body fat (%) was measured by means of a computerized model of near infrared interactance (IRI) ("FUTREX") on the dominant upper arm. The energy and protein intake were 1731 +/- 292 kcal. and 86.9 +/- 17.2 g (n = 4) during the first recording period of food intake. In the second period the energy and protein intake were 1676 +/- 105 kcal and 72.7 +/- 10.2 g (n = 4) (NS). The total body fat increased from 19.8 +/- 2.9 to 22.5 +/- 3.0 (p < 0.05), in spite of unchanged total body weight. PD patients seem to accumulate fat during PD treatment with glucose as osmotic agent. This may influence the cardiovascular risks. The results indicate nutritional adjustments and possibly also increased physical activity.


Peritoneal function tests: usefulness of simplified methods.

The Peritoneal Equilibration Test (PET) as standardized by Twardowski (T) and simplified Mass Transfer Coefficients (MTC) as per Garred (G) and Krediet (K) have been employed in our patients to assess: 1) the reproducibility of results, 2) correlation between methods, and 3) usefulness of patient categorization by simplified methods in contrast to PET patterns. We have performed 29 standardized PET (Dianeal 2.5%) in 24 stable CAPD patients. We have collected dialysate samples at 0, 30, 60, 120, 180 and 240 minutes. With this data we were able to calculate the dialysate/plasma ratio for PET, MTC as per Garred and MTC as per Krediet. Our results were not significantly different from data reported by the original authors, except for PET D/P urea at 240': 0.91 +/- 0.07(T) vs. 0.87 +/- 0.08 (our), p < 0.05. In our patients, good correlation was found between PET and MTC for urea, creatinine, and glucose, using both formulae (G and K). Patient categorization as High, High Average, Low Average, and Low by MTCs can well predict PET categorization with acceptable sensitivity and good specificity. We conclude there is good reproducibility of the methods. There is also a close correlation between PET, K and G methods for solute transport evaluation and patient categorization. Simplified methods can be substituted for the more complex ones.


Pharmacokinetics of ciprofloxacin after intraperitoneal administration in uninfected patients undergoing CCPD.

Ciprofloxacin is increasingly used to treat peritoneal dialysis related peritonitis. We studied the pharmacokinetics of intraperitoneally administered ciprofloxacin in six uninfected CCPD patients. In a randomized cross-over setting ciprofloxacin was added either to a long dwell exchange (lastbag) or to four short dwell exchanges (dwell time 1.5 h). Addition of ciprofloxacin (25 mg/l) during the four short dwell exchanges resulted in dialysate levels of 21.1-13.3 mg/l during these exchanges. In the subsequent last bag devoid of ciprofloxacin a dialysate Cmax,D of 1.38 mg/l was observed at 30 min. Mean +/- SD serum Cmax,S was 0.59 +/- 0.29 mg/l after 5.4 h. Instillation of 100 mg/l ciprofloxacin in the last-bag yielded Cmax,D of 99.1 mg/l, falling with a t1/2 of 3.3 h towards levels < 2 mg/l at 19.8 h. A mean +/- SD serum Cmax,S of 0.69 +/- 0.19 was reached after 4 h. During four subsequent 1.5h exchanges without ciprofloxacin dialysate levels were < 0.1 mg/l. Instillation of 25 mg/l ciprofloxacin in the last-bag yielded a Cmax,D of 21.7 mg/l, falling towards levels < 2 mg/l at 15 h with a t1/2 of 3.85 h. A mean +/- SD serum Cmax,S of 0.26 +/- 0.03 was reached after 8 h. We conclude that the rapid absorption of ciprofloxacin from the dialysate into the tissues requires ciprofloxacin to be administered to all CCPD bags to ensure bactericidal dialysate levels. When therapeutic serum levels are required higher intraperitoneal doses or an oral or i.v. loading dose is warranted.


Evaluation of CNS-function in CAPD patients using magnetoencephalography (MEG): comparison with hemodialysis patients.

In order to evaluate the CNS-function of uremic patients, the magnetic activity emitted from the brain of 20 pts (10 pts on CAPD and 10 on HD) was measured. MEG consisted of taking 32 consecutive records from the 32 equally spaced points chosen on the skull in uremic pts around our reference points T3, T4, P4, F3, F4 of the international 10-20 electrode placement point system. MEG data were converted using an AD-converter with sampling frequency 256 Hz and stored in a P/C. Our results showed significant differences between the two groups. In all HD pts there was abnormal magnetic brain activity with high spectral amplitudes (in the band 2-7 Hz) which was more prominent in pts in hemo for more than 4 years. The magnetic activity was within normal ranges in all CAPD pts. We conclude that: 1) There is high magnetic brain activity in HD pts, which in accordance with the EEG findings are signs of diffuse encephalopathy. 2) CAPD pts show a very low magnetic brain activity which must be interpreted as normal brain function, and 3) MEG can be useful in further measurement of adequacy of dialysis.


CAPD in end stage patients with renal disease due to diabetes mellitus--an update.

Large numbers of diabetics with renal failure have been treated by continuous ambulatory peritoneal dialysis (CAPD). Overall 1-year patient survival varies from 51% to 87%. Mortality is due to cardiovascular disease in more than 50% of the cases. Young diabetics with good blood pressure control and without cardiac disease have a chance at long survival on CAPD. In comparison to hemodialysis, CAPD yields better patient survival for young diabetics and worse for old diabetics, worse technique survival, probably greater overall morbidity, and similar rates of progression of retinopathy, neuropathy and peripheral vascular disease. Adequacy of peritoneal clearance and peritoneal ultrafiltration characteristics are similar between diabetics and non-diabetics on CAPD. CAPD is associated with better preservation of renal function than hemodialysis in diabetics. The rates of CAPD peritonitis do not differ substantially between diabetics and non-diabetics. However, diabetes appears to be associated with higher incidence of tunnel infection. Hyperlipidemia is generally less severe in diabetics than non-diabetics on CAPD, but malnutrition is more frequent in diabetics. CAPD has many attractive features and several drawbacks for the management of diabetics with end stage renal failure (ESRF). Its ultimate success will depend on the outcome of efforts to improve cardiovascular mortality, malnutrition, hyperlipidemia and catheter-related infections.


Multiple use of cycler set in cycler peritoneal dialysis.

To evaluate the multiple use of cycler set with universal connector set. The study was designed to reuse the cycler set for two to three treatments, each of 16-24 hours using Pac-X or Pac-Xtra cycler and to continue to use the same set if the patient was disconnected for any reason. Tertiary-referral university hospital. 204 ESRD patients on peritoneal dialysis (PD) admitted to University Hospital from January 1989 to July 1991 were studied. The patients were disconnected and reconnected in between or during PD treatments. Five-liter dialysate bags were used. All the fluid was either set initially or added as clinically indicated. 2491 cycler PD treatments were performed with Pac-X and Pac-Xtra cyclers using 940 cycler tubing sets. 1624 disconnections were made in between and 336 were made for radiological investigations, special procedure, physical therapy and surgery during PD treatments. No episode of peritonitis or mechanical failure occurred. The multiple use resulted in 62% reduction in cycler sets thereby reducing the disposable supplies and a substantial saving in the nursing time. The multiple use of cycler set with universal connector and manifold set was safe and economical in the patients undergoing cycler PD in the hospital setting.


A comparison of sleep-disordered respiration in ESRD patients receiving hemodialysis and peritoneal dialysis.

To compare sleep-disordered respiration in ESRD patients receiving peritoneal dialysis and hemodialysis. Subjective and objective measures of sleep were recorded in two groups of ESRD patients receiving PD and HD. Tertiary-referral university hospital Fifteen PD patients (12 males, 3 females) and 15 HD patients (11 males, 4 females) were studied for two nights in the sleep laboratory. Ten of the 15 PD patients and 8 of the 15 HD patients reported multiple types of sleep difficulties (NS). In the PD group, seven described substantial difficulty initially going to sleep; ten were troubled by awakenings during the night, while seven suffered from daytime sleepiness. In the HD group, seven described substantial difficulty initially going to sleep; eight were troubled by awakenings during the night, while five experienced day-time sleepiness. No significant difference was observed in total sleep time, intermittent wake time, sleep latency, sleep efficiency, total disordered breathing events, minimum oxygen saturation and periodic leg movements between the PD and HD groups. Sleep apnea was noted in 9 of 15 PD and 8 of 15 HD patients. This study indicates that the incidence and severity of sleep apnea is similar in ESRD patients receiving chronic peritoneal dialysis and hemodialysis.


Peritoneal dialysis training in a patient with multiple congenital anomalies.

We report an adult patient with multiple congenital anomalies including absent right arm, short stature, and scoliosis who has been trained and successfully performs continuous cycling peritoneal dialysis independently. Motivated patients with end stage renal disease and various anomalies should be considered for peritoneal dialysis training.