Rds and Rih mediate hypersensitive cell death independent of gene-for-gene resistance to the oat crown rust pathogen Puccinia coronata f. sp. avenae

The Pca crown rust resistance cluster in the diploid Avena genus confers gene-for-gene specificity to numerous isolates of Puccinia coronata f. sp. avenae. Recombination breakpoint analysis indicates that specificities conferred by the Pca cluster are controlled by at least five distinct genes, designated Pc81, Pc82, Pc83, Pc84, and Pc85. Avena plants with the appropriate genotype frequently respond to P. coronata by undergoing hypersensitive cell death at the sites of fungal infection. Autofluorescence of host cells in response to P. coronata occurs in plants that develop visible necrotic lesions but not in plants that lack this phenotype. Two newly described, non-Pc loci were shown to control hypersensitive cell death. Rds (resistance-dependent suppressor of cell death) suppresses the hypersensitive response (HR), but not the resistance, mediated by the Pc82 resistance gene. In contrast, Rih (resistance-independent hypersensitive cell death) confers HR in both resistant and susceptible plants. Linkage analysis indicates that Rds is unlinked to the Pca cluster, whereas Rih is tightly linked to it. These results indicate that multiple synchronous pathways affect the development of hypersensitive cell death and that HR is not essential for resistance to crown rust. Further characterization of these genes will clarify the relationship between plant disease resistance and localized hypersensitive cell death.

[It is a long way from Slagelse to Sebastopol]

Above I have told the story of Frederik Lov, who was the brother of my great-great-grandmother. He was born in 1802 as son of a watchmaker and graduated from the grammar school in Slagelse in 1822, the very year when the fairyteller Hans Christian Andersen was sent to the same school. Frederik Lov went to Copenhagen to study at >>The Royal Surgical Academy<<, but just before his final graduation he left for St. Petersburg in Russia as the Russian government had invited senior medical students and young doctors to come to work in Russia. True, it has been promised that the students could pass their exam in Russia in their native language. However, it turned out that Danish was not covered, so instead he was examined in Latin and passed his examination in 1828. He started his medical career at the naval hospital in Archangelsk, where he stayed for two years and learned to speak Russian. In 1830 he went with the frigate >>Smirna<< from Archangelsk towards Kronstadt, but was shipwrecked near Halmstad in Sweden. He was saved and could continue the journey one month later. In Kronstadt he was offered to join the Black Sea navy. He went to Sebastopol, where he stayed for the rest of his life. He participated in several military actions, especially in the Caucasian area. During the Crimean War he worked as a doctor in the fortifications of Sebastopol. At that time his family was evacuated and his house was destroyed by bombs. In 1874 he died as a highly decorated man. Frederik Lov's son Karl was also an officer. He was involved in battles in Caucasus like his father. After having left the army he became chief of the telegraph station of Sebastopol and later on the manager of the public bank of the town and elected member of the Duma. He lived at the house of Frederik Lov, which had been rebuilt after the Crimean War, and ever since descendents of Frederik Lov, lived in this house until it was destroyed by German bombs in 1942 and never rebuilt. A great-great-granddaughter of Frederik Lov, Olga Kulago, participated in the defense of Sebastopol in 1942 and was evacuated to Caucasus. After the war she studied medicine and graduated in 1950. She worked as an obstetrician until her retirement in 1977.

Vitamin D and estrogen receptor gene polymorphisms in type 2 diabetes mellitus and in android type obesity

OBJECTIVE

We studied the significance of BsmI restriction enzyme polymorphism of the vitamin D receptor (VDR) gene and the XbaI and PvuII polymorphisms of the estrogen receptor (ER) gene in patients with type 2 diabetes (n=49), android type obesity with normal carbohydrate metabolism (n=29) and healthy controls (n=138).

METHODS

The distribution of genotypes in the study groups, as well as their relationship to fasting and 1 h postprandial serum C-peptide levels were analyzed.

RESULTS

Postprandial serum C-peptide levels of BB genotypes were significantly higher in the diabetes and obese groups (6.18+/-5.09 ng/ml) compared with other genotypes (2.71+/-2.45 vs. 1.72+/-1.97 ng/ml, respectively, P=0.05). Among patients with type 2 diabetes and obese subjects, the XX allelic variant of the ER gene was more frequent (P=0.00015). Postprandial C-peptide levels of subjects exhibiting XX genotype were significantly lower compared with those with Xx genotype (1.67+/-2.16 vs. 3.8+/-3.72 ng/ml, P=0.021). The BBXx allelic combination of the VDR/ER receptor genes was less frequent in diabetic patients than in healthy subjects or in obese patients. The BBXx genotype was associated with significantly elevated postprandial C-peptide levels in all subjects compared with other combinations (9.65+/-3.14 vs. 1.35+/-2.82 ng/ml, P=0.003). No difference was found in the distribution of the PvuII polymorphism of the ER gene or in the association with the C-peptide levels among study groups.

CONCLUSION

Polymorphisms of the VDR/ER receptor genes might play a role in the pathogenesis of type 2 diabetes by influencing the secretory capacity of beta-cells.

Renal structure in neotropical bats: using stable isotopes to explore relationships between diet and morphology

The relationship between kidney structure and diet was examined in several species of bats from the tropics. The trophic level of the bats was determined by their stable nitrogen isotopic composition (delta15 N). The results indicate that the relative thickness of the renal medulla is directly related to the trophic level of the bats. Additionally, we also determined the relationship between body mass and kidney structure. Relative medullary thickness was reciprocally related to body mass in animalivorous bats but no relationship was found in phytophagous bats. Stable isotope analysis provided a quantitative approximation of diet to test its relationship with kidney structure.

Differential expression of intracisternal A-particle transcripts in immunogenic versus tumorigenic S49 murine lymphoma cells

Tumorigenic S49 mouse lymphoma cells (T-25) were compared to their nontumorigenic (immunogenic) substrate-adherent descendants (T-25-Adh), using the differential display technique. A 784-bp fragment with 92% sequence homology to the intracisternal A-particle (IAP) element family was isolated from the latter cells. IAP sequences are endogenous, noninfectious retroviral elements that can undergo transpositions and act as mutagens. Expression of IAP transcripts (as detected by the isolated fragment) was 5- to 10-fold higher in T-25-Adh cells than in T-25 cells. IAP RT-PCR cDNA clones derived from the immunogenic T-25-Adh cells, but not from T-25 cells, contain two distinctive motifs: (i) a motif characteristic of IAP elements expressed in lymphoid cells (lymphocyte specific, LS); (ii) a nonapeptide sequence known to stimulate cytotoxic T lymphocytes in a leukemia cell line expressing IAP sequences. In addition, expression of transcripts containing these motifs is enhanced in the immunogenic cells as opposed to the tumorigenic cells. Furthermore, one of the IAP elements (belonging to the LS1 subfamily) is specifically hypomethylated in the DNA of the immunogenic cells. The above-mentioned relationship was strengthened when tumorigenic revertants derived from T-25-Adh cells, as well as independently selected tumorigenic and immunogenic S49 sublines, were studied. In all cases, enhanced immunogenicity was linked to the up-regulation of specific IAP elements. No transpositions of LS1 elements were observed among the different sublines studied. These findings suggest that, in the S49 lymphoma, selectively expressed IAP retroviral elements may function in a tumor suppressive capacity by affecting the immunogenic potential of these cells.

Scale-invariant fluctuations at different levels of organization in developing heart cell networks

In the last few years it has been realized that the intervals of spontaneous spiking events in the intact heart exhibit coexisting scale-invariant count fluctuations and anticorrelated interspike intervals fluctuations. Here, we show experimentally that this feature is an intrinsic property of single isolated heart cells, which is preserved when the cells couple into networks. We present a model explaining this behavior at both the single cell and network levels.

Nonfluoroscopic endocardial catheter mapping of atrial fibrillation

The treatment of drug-refractory atrial fibrillation (AF) remains one of the unsolved problems in cardiology. Surgical interventions have demonstrated that AF can be prevented by multiple incisions within both atria. Recently, this strategy has been translated into a catheter procedure. So far, the ablation approach is not based on individual electrophysiologic data, but constitutes only an anatomic approach. Further insight into the spatial and temporal distribution of the local electrograms during AF is needed. Electroanatomic maps acquired by sequential mapping over 45 seconds at each site during AF in six patients with paroxysmal AF were analyzed off-line. Electrograms were sampled at a mean of 36 +/- 12 sites in the left atrium of each patient. A total of 217 sites were sampled, of which 27.3% (59) represented type A (regular) AF, 9.7% (21) represented type B (totally irregular), and 63.1% (137) represented type C (mixture of type A and B) electrograms. The distribution was analyzed in 20 different segments of the left atrium, and a significantly higher incidence of type A electrograms was found in area 3 (upper lateral pulmonary vein) than at all other sites (P < 0.005). This observation needs further confirmation before any conclusion with regard to catheter ablation can be drawn, particularly because the analysis was based on bipolar recordings from a 4-mm tip electrode.

DNA-templated assembly and electrode attachment of a conducting silver wire

Recent research in the field of nanometre-scale electronics has focused on two fundamental issues: the operating principles of small-scale devices, and schemes that lead to their realization and eventual integration into useful circuits. Experimental studies on molecular to submicrometre quantum dots and on the electrical transport in carbon nanotubes have confirmed theoretical predictions of an increasing role for charging effects as the device size diminishes. Nevertheless, the construction of nanometre-scale circuits from such devices remains problematic, largely owing to the difficulties of achieving inter-element wiring and electrical interfacing to macroscopic electrodes. The use of molecular recognition processes and the self-assembly of molecules into supramolecular structures might help overcome these difficulties. In this context, DNA has the appropriate molecular-recognition and mechanical properties, but poor electrical characteristics prevent its direct use in electrical circuits. Here we describe a two-step procedure that may allow the application of DNA to the construction of functional circuits. In our scheme, hybridization of the DNA molecule with surface-bound oligonucleotides is first used to stretch it between two gold electrodes; the DNA molecule is then used as a template for the vectorial growth of a 12 microm long, 100 nm wide conductive silver wire. The experiment confirms that the recognition capabilities of DNA can be exploited for the targeted attachment of functional wires.

Preparative enantiomer separation of the inhalation anesthetics enflurane, isoflurane and desflurane by gas chromatography on a derivatized gamma-cyclodextrin stationary phase

The preparative enantiomeric separation of the inhalation anesthetics enflurane (1) and isoflurane (2) in very high chemical (> 99.5%) and enantiomeric excess (ee > 99%) by gas chromatography (GC) on octakis(3-O-butanoyl-2,6-di-O-n-pentyl)-gamma-cyclodextrin (4), dissolved in the apolar polysiloxane SE-54 and coated on Chromosorb P AW DMCS, is described. Up to 1 g of each enantiomer of 1-2 can been obtained per diem. The enantiomers of the highly volatile desflurane (3) can also be separated, albeit with diminished ee. The enantiomeric excess of 1-3 was checked by analytical GC on 4 and the absolute configuration of 2 and 3 has been determined via anomalous X-ray diffraction.

Effects of density and gating of delayed-rectifier potassium channels on resting membrane potential and its fluctuations

The aim of this study is to evaluate directly, using a reduced experimental system, the nature of interactions between voltage-gated potassium channels and the resting membrane potential. Xenopus oocytes were injected with various concentrations of cRNA coding for a delayed-rectifier potassium channel Shaker-IR. The effects of the density and kinetics of the expressed channels on resting membrane potential is explored in isolated ("inside-out") patches. The channel density is given in terms of maximal conductance (Gmax), measured from the maximal slope of the I-V curve under voltage clamp conditions. The capacitance of the experimental setup is approximately 1 pF. At high channel densities (Gmax > 10 pA/mV) the mean membrane potential is stabilized at approximately -60 mV. This resting membrane potential is more than 35 mV positive to the reversal potential for potassium ions under the same experimental conditions. Analyses of voltage clamp experiments indicate that at high channel densities the mean membrane potential is determined by the rates of channel activation and deactivation, but is not affected by the rates involved in the process of slow (C-type) inactivation. In contrast, at lower channel densities membrane potential is very unstable, and its mean value and amplitude of fluctuations are strongly affected by the process of slow (C-type) inactivation.

Modulation of histamine release by sodium, potassium adenosine triphosphatase inhibition

BACKGROUND

Previous studies have shown that a sodium, potassium adenosine triphosphatase inhibitor is present in the plasma of allergic subjects in whom enhanced histamine releasability has also been reported.

PURPOSE

The purpose of this study was to determine the effect of in vitro sodium, potassium adenosine triphosphatase inhibition on whole blood histamine release.

METHODS

Samples obtained from 12 patients with allergic rhinitis and 12 nonallergic subjects were incubated in duplicate for 30 minutes with anti-IgE antibody (100 micrograms/mL) or control buffer following a 0-, 10-, 20-, 30-, 60-, 120- and 180-minute preincubation with ouabain (3.0 mM) or diluent. Cell supernatants were assayed for histamine by radioimmunoassay and results were expressed as a percentage of total histamine release.

RESULTS

Mean (+/- 1 SEM) anti-IgE induced release, in the presence and absence of ouabain, respectively, for allergic subjects was 27.5 +/- 5.5 and 21.0 +/- 4.5 (ten minutes, P < 0.05), 30.3 +/- 6.0 and 22.4 +/- 4.8 (20 minutes, P < .025), 28.9 +/- 5.2 and 23.5 +/- 4.1 (30 minutes), 33.8 +/- 7.1 and 26.7 +/- 5.4 (60 minutes, P < .05), 43.2 +/- 7.5 and 24.3 +/- 4.6 (120 minutes, P < .001), and 34.5 +/- 5.0 and 29.8 +/- 5.4% (180 minutes). Spontaneous histamine release in allergic subjects was also significantly increased by ouabain. Mean (+/- SEM) spontaneous release, in the presence and absence of ouabain, respectively, for allergic subjects was 2.0 +/- 0.5 and 0.9 +/- 0.2 (60 minutes, P < .025), 2.8 +/- 0.5 and 1.9 +/- 0.4 (120 minutes, P < .05), and 5.4 +/- 1.5 and 3.9 +/- 0.8% (180 minutes, P < .005). Ouabain did not significantly alter histamine release in non-allergic subjects.

CONCLUSIONS

These data show that ouabain induced a significant increase in both spontaneous and induced histamine release in allergic subjects. In vivo, sodium, potassium adenosine triphosphatase inhibition may have an effect on histamine release in allergic subjects.

Colorectal cancer in the Ukraine: analysis and statistical data

Colorectal cancer is the third most common cause of death due to malignancy in the Ukraine (21.7 per 100,000 in 1992). Only lung cancer (43.6) and stomach cancer (30.6) occur more frequently. Mortality is high; 47.9% and 38% of patients dying from colon and rectal cancer, respectively, within 1 year. The majority of patients present with advanced disease; 71.5% of patients with colon cancer and 60.1% of patients with rectal cancer have stage 3 or 4. Only 20.4% of patients with colon cancer and 29.4% with rectal cancer are suitable for radical surgery. The range of operative procedures performed reflects the stage of disease. Improvement in operability and survival figures in the Ukraine will result from improved facilities, increased public awareness of colorectal disease, introduction of screening programmes and closer links forged between the Ukraine and other European centres.

Centrally tinted contact lenses. A useful visual aid for patients with achromatopsia

Achromatopsia (rod monochromacy) is a congenital color-vision defect of autosomal recessive inheritance due to severely abnormal or totally absent cone function. The disease is characterized by markedly reduced visual acuity, nystagmus, and, often, ametropia. Even under normal daylight conditions, these patients are extremely handicapped by glare because of a lack of rod inhibition by the abnormal or deficient cones. Light-absorbing glasses (absorption > 90%) can ameliorate this visual impairment to a certain extent but are sometimes not accepted by the patient since they are felt to disfigure the face. Especially during the first few years of school, this can lead to psychological problems. A special contact lens (Hydroflex, Wöhlk Company, Kiel) with a centrally tinted area (absorption 80%) that is slightly greater in diameter than the pupil under daylight conditions can correct ametropia and reduce light exposure and dazzle in a cosmetically much better way. Our first experience with this kind of visual aid in a 9-year-old girl suffering from incomplete achromatopsia is presented.

Rich dynamics in a simplified excitable system

The study aims at exploring effects of microscopic channel fluctuations on macroscopic dynamics of excitable systems. Molecular biology techniques are used in order to construct a minimal excitable system that is built of cloned channels embedded in a small (approximately 1 micron 2) isolated patch of membrane. This simple synthetic "point" system exhibits dynamics in time scales that are several orders of magnitude longer then a single spike.

Delivery of cytokines by liposomes. II. Interleukin-2 encapsulated in long-circulating sterically stabilized liposomes: immunomodulatory and anti-tumor activity in mice

We have recently demonstrated that recombinant human interleukin-2 (IL-2) can be successfully encapsulated in small (mean size, 65 nm), unilamellar, long-circulating, sterically stabilized liposomes (SSL, also known as Stealth liposomes). The present study was undertaken to assess in mice the immunomodulatory and anti-tumor effects of SSL-IL-2 in comparison with soluble, unmodified IL-2 and pegilated IL-2 (PEG-IL-2). The main findings were as follows: (a) SSL-IL-2 was significantly more effective than IL-2 in increasing leukocyte number in the blood and spleen (p < 0.05) and triggering spleen lymphokine-activated killer cell activity (p < 0.01; t test). (b) In mice with advanced metastatic carcinoma previously treated with chemotherapy (cyclophosphamide), the survival was two to six times greater following administration of SSL-IL-2 as compared with IL-2 (p < 0.05; log-rank test). Moreover, successful treatment with SSL-IL-2 required lower cumulative doses (1.25 x 10(5) vs. 2.5 x 10(5) CU) and fewer (two versus five) administrations. (c) PEG-IL-2 was a more potent immunostimulator than SSL-IL-2 in normal mice and as effective therapeutically as SSL-IL-2 in tumor-bearing mice. The former agent, however, often caused marked toxicity (up to 40% mortality in some experiments), including severe thrombocytopenia. These findings suggest that SSL-IL-2 is an immunopotentiating agent superior to IL-2 in both normal mice and in tumor-bearing mice pretreated with chemotherapy.

Delivery of cytokines by liposomes. I. Preparation and characterization of interleukin-2 encapsulated in long-circulating sterically stabilized liposomes

In an attempt to enhance the therapeutic efficacy of interleukin-2 (IL-2), recombinant human IL-2 was encapsulated either in large conventional liposomes or in small (mean diameter 65 nm), unilamellar, long-circulating, extravasating liposomes [referred to as sterically stabilized liposomes (SSLs)]. The SSL-IL-2 activity was assessed in vitro and in mice in comparison with soluble IL-2, IL-2 in conventional liposomes (non-SSL-IL-2), and pegilated IL-2 (PEG-IL-2). The main observations were as follows: (a) SSLs were far better carriers than conventional liposomes with regard to encapsulation efficiency and pharmacokinetics; (b) > 85% of IL-2 biological activity was consistently encapsulated in SSLs; (c) SSL-IL-2 was much more stable than soluble IL-2 at 4 and 37 degrees C; (d) SSL-IL-2, but not "empty" liposomes, bound in vitro to IL-2 receptor-bearing T-cells, indicating that the domain of the cytokine molecule involved in binding to the receptor is exposed on the outer liposome membrane; (e) release of IL-2 from the liposomes was not required for its in vitro biological activity; (f) plasma half-lives (t1/2 alpha, t1/2 beta) and area under the curve (AUC) of SSL-IL-2 were 10-30 times greater than those of soluble IL-2 and similar to those of PEG-IL-2; and (g) IL-2 is released from the SSLs in vivo with a t1/2 of approximately 40 min, although the SSL-IL-2s retained their steric stabilization in the plasma for > 4 h, with little liposome accumulation in the reticuloendothelial system. These data, together with the improved immunomodulatory and antitumor activity of SSL-IL-2 in mice, suggest that SSL-IL-2 might be a therapeutic agent superior to soluble IL-2.

Stationary phase in the yeast Saccharomyces cerevisiae

Growth and proliferation of microorganisms such as the yeast Saccharomyces cerevisiae are controlled in part by the availability of nutrients. When proliferating yeast cells exhaust available nutrients, they enter a stationary phase characterized by cell cycle arrest and specific physiological, biochemical, and morphological changes. These changes include thickening of the cell wall, accumulation of reserve carbohydrates, and acquisition of thermotolerance. Recent characterization of mutant cells that are conditionally defective only for the resumption of proliferation from stationary phase provides evidence that stationary phase is a unique developmental state. Strains with mutations affecting entry into and survival during stationary phase have also been isolated, and the mutations have been shown to affect at least seven different cellular processes: (i) signal transduction, (ii) protein synthesis, (iii) protein N-terminal acetylation, (iv) protein turnover, (v) protein secretion, (vi) membrane biosynthesis, and (vii) cell polarity. The exact nature of the relationship between these processes and survival during stationary phase remains to be elucidated. We propose that cell cycle arrest coordinated with the ability to remain viable in the absence of additional nutrients provides a good operational definition of starvation-induced stationary phase.

Solitary blood cultures as a quality assurance indicator

For patients with suspected bacteremia, at least two separate blood cultures are recommended to achieve maximum sensitivity and to properly interpret results. Since a single blood collection may signify an improper procedure with serious consequences if the diagnosis of blood stream infection is missed, we investigated this problem with studies at three teaching hospitals (A, B, and C) and by a survey of 38 other hospitals. The incidence of solitary blood cultures ranged from 1 to 99% (median 26%) at the surveyed institutions. Among the cases investigated at hospitals B and C, between 10 and 30% of solitary blood cultures were not clinically indicated, while most of the others were caused by the physician not knowing that one culture was insufficient or by failure to complete the diagnostic plan. Focused concurrent intervention at hospital B was associated with reductions in solitary blood cultures from 40.0 to 24.6% (p = 0.045) and a decline in those not indicated from 38.1 to 12.5% (p = 0.192). Global educational efforts at hospital A were associated with a decrease in solitary blood culture rates from 52 to 37% (p = 0.016). These results show that blood culture practice varies widely among institutions in spite of consensus recommendations for proper specimen collections. We estimate that, nationwide, up to 18,000 etiologic diagnoses of bacteremia are missed annually because of this problem. Monitoring institutional solitary blood cultures is recommended as a test utilization indicator and as the basis for improving blood culture practice.

Bcy1, the regulatory subunit of cAMP-dependent protein kinase in yeast, is differentially modified in response to the physiological status of the cell

The regulatory subunit of cAMP-dependent protein kinase in yeast, encoded by the BCY1 gene, is known to be required under certain conditions such as growth on nonfermentable carbon sources and entry into stationary phase. We have identified novel isoforms of Bcy1 in cells under these conditions. The isoforms are distinguishable by their migration on one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and 2-dimensional nonequilibrium pH gradient gel electrophoresis. The isoforms observed by one-dimensional SDS-PAGE bind cAMP, as determined by [32P]8-azido-cAMP labeling (diagnostic of Bcy1 protein). Proteins isolated from cells grown to stationary phase in rich medium exhibit five antibody-reactive bands, by one-dimensional SDS-PAGE immunoblot analysis, with apparent molecular masses of 50, 52, 55, 59 and 61 kDa. Total Bcy1 protein increases at least 8-fold between exponential and stationary phase. Analysis of proteins from a variety of yeast mutants indicated that 1) many of the observed modifications of Bcy1 are dependent upon the presence of the Ser-145 phosphorylation site; 2) the appearance of the 59- and 61-kDa bands is dependent upon the presence of Yak1 kinase; and 3) Bcy1 protein is modified even in the absence of cAMP-dependent protein kinase catalytic subunits. Cells carrying the bcy1(ala145) allele exhibit non-wild type growth, indicating that these modifications may be functionally significant.

[Anomalous origin of the left coronary artery from the pulmonary artery (Bland-White-Garland syndrome) in a 29-year-old male with absolute tachyarrhythmia]

We report on a man without any symptoms until the age of 29 years when a ventricular tachyarrhythmia occurred for the first time. There were electrocardiographic signs of a previous myocardial infarction of the anterior wall, but there had not even been any episode of angina pectoris. The cause was the anomalous origin of the left coronary artery from the pulmonary trunk (Bland-White-Garland syndrome). Therapy consisted of ligation of the left coronary artery and the implantation of an aortocoronary vein graft to the left coronary artery in order to reinstall a two-coronary system. Diagnosis is easily made by coronary angiography. At a 3-year follow-up there was an increase of the ejection fraction/cardiac output, a stable sinus rhythm, and an improved physical endurance.

Improving CD4+ lymphocyte counts in HIV-infected hemophilia patients. A favorable prognostic indicator?

CD4+ lymphocyte counts of 91 HIV+ hemophilia patients were monitored for a mean of 4 years (range: 15-69 months). CD4+ lymphocytes decreased in 55 but increased in 36 patients over time. The CD4+ cell increases were persistent in 5 patients, whereas they fluctuated in 31. Of the 36 patients with increasing CD4+ counts 3 developed AIDS and 1 LAS. The other 32 patients were clinically asymptomatic (CDC II), but had immunological abnormalities, such as increased serum neopterin (N = 18) and impaired in vitro T cell responses to pooled allogenic stimulator cells (N = 15) or mitogens (N = 18). In contrast, of the 55 patients whose CD4+ cells decreased, 24 developed AIDS and 5 ARC (P less than 0.0005). Only 2 of these 55 patients had normal mitogen stimulation in vitro and normal serum neopterin levels.

[Choledochal cyst. The clinical picture, diagnosis and therapy]

A 21-year-old woman who for more than one year had had epigastric pain which was unrelated to food and radiated belt-like, was found to have a marked increase in gamma-GT, slightly elevated phosphatase activity, and increased erythrocyte sedimentation rate. The diagnosis of choledochal cyst, type Ia, was confirmed by sonography, endoscopic retrograde pancreatography and intravenous cholangiography. A choledochocystojejunostomy with a Y-Roux anastomosis was constructed to stop the cholestasis and prevent complications. The patient became symptom-free after the operation.

Toxicological interactions between carbon monoxide and carbon dioxide

Fischer 344 male rats were subjected to 30-min individual or combined exposures of carbon monoxide (CO) and carbon dioxide (CO2). All deaths from CO occurred during the exposures, and the LC50 values were 4600 and 5000 ppm, depending on experimental conditions. Animals exposed to CO2 concentrations ranging from 1.3 to 14.7% for 30 min were neither incapacitated nor fatally injured. The addition of nonlethal concentrations of CO2 (1.7 to 17.3%) to sublethal concentrations of CO (2500 to 4000 ppm) caused deaths of the exposed rats both during and following (up to 24 h) the 30-min exposures. The most toxic combination of these two gases (2500 ppm CO plus 5% CO2) increased the rate of carboxyhemoglobin (COHb) formation 1.5 times that found in rats exposed to 2500 ppm of CO alone. The COHb equilibrium levels were the same. Exposure to both CO and CO2 produced a greater degree of acidosis and a longer recovery time than that observed with either single gas. The results fit a mathematical model indicating a synergistic interaction. Combustion of 11 materials at their LC50 values indicated that CO was probably the primary toxicant in one case and that the combined CO plus CO2 was the cause of the deaths in three other cases. Additional fire gases need to be studied to explain deaths from the other materials.

[Unapparent course of pancreatitis with pseudocyst development and cholestatic jaundice in anticonvulsive therapy with valproate]

Valproic acid is a reliable and comparatively safe drug in the treatment of special forms of absence seizures. Severe but very rare complications include acute liver necrosis and acute pancreatitis which may end lethally. A case of a previously unreported association of pancreatic pseudocyst and development of cholestatic icterus in conjunction with valproic acid therapy is presented. The clinical signs of icterus and chronic pancreatic failure disappeared when we terminated the therapy.

[Urinary concentration of cobalt and chromium in patients with a non-cemented total hip prosthesis]

The concentrations of cobalt and chromium have been measured in the urine of 22 patients who had received uncemented hip prostheses made from cobalt, chromium and molybdenum alloy, and in 21 patients who had not received prostheses, using absorption spectrophotometry. The results were statistically analysed using the Wilcoxon test. The levels of cobalt in the urine in the patients with uncemented prostheses did not show a significant increase, indicating that there is no greater risk of cobalt toxicity. The concentration of chromium was significantly raised (p less than 10(-2) in the urine of patients with uncemented prostheses, and in three of these patients significant corrosion had occurred.

[Complications and reconstructive interventions of the efferent urinary system following kidney transplantation]

It is reported on early and late complications on the efferent urinary system by 667 transplantations of allogenic kidneys of corpses. The complication rate runs to 6.3%. Indication and performance of reconstructive surgical interventions are descended to in detail.