Glomerular transcriptomics predicts long term outcome and identifies therapeutic strategies for patients with assumed benign IgA nephropathy

Some patients diagnosed with benign IgA nephropathy (IgAN) develop a progressive clinical course, not predictable by known clinical or histopathological parameters. To assess if gene expression can differentiate between progressors and non-progressors with assumed benign IgAN, we tested microdissected glomeruli from archival kidney biopsy sections from adult patients with stable clinical remission (21 non-progressors) or from 15 patients that had undergone clinical progression within a 25-year time frame. Based on 1 240 differentially expressed genes from patients with suitable sequencing results, we identified eight IgAN progressor and nine non-progressor genes using a two-component classifier. These genes, including APOL5 and ZXDC, predicted disease progression with 88% accuracy, 75% sensitivity and 100% specificity on average 21.6 years before progressive disease was clinically documented. APOL lipoproteins are associated with inflammation, autophagy and kidney disease while ZXDC is a zinc-finger transcription factor modulating adaptive immunity. Ten genes from our transcriptomics data overlapped with an external genome wide association study dataset, although the gene set enrichment test was not statistically significant. We also identified 45 drug targets in the DrugBank database, including angiotensinogen, a target of sparsentan (dual antagonist of the endothelin type A receptor and the angiotensin II type 1 receptor) currently investigated for IgAN treatment. Two validation cohorts were used for substantiating key results, one by immunohistochemistry and the other by nCounter technology. Thus, glomerular mRNA sequencing from diagnostic kidney biopsies from patients with assumed benign IgAN can differentiate between future progressors and non-progressors at the time of diagnosis.

Glomerular proteomic profiling of kidney biopsies with hypertensive nephropathy reveals a signature of disease progression

Hypertensive nephropathy (HN) requires a kidney biopsy as diagnostic gold-standard but histological findings are unspecific and specific prognostic markers are missing. We aimed at identifying candidate prognostic markers based on glomerular protein signatures. We studied adult patients (n = 17) with eGFR >30 ml/min/1.73m² and proteinuria <3 g/d from the Norwegian Kidney Biopsy Registry, including subjects non progressing (NP, n = 9), or progressing (P, n = 8) to end-stage renal disease (ESRD) within an average follow-up of 22 years. Glomerular cross-sections from archival kidney biopsy sections were microdissected and processed for protein extraction. Proteomic analyses were performed using Q-exactive HF mass spectrometer and relative glomerular protein abundances were compared between P and NP patients. Immunohistochemistry (IHC) was used to validate selected data. Amongst 1870 quality filtered proteins, 58 were differentially expressed in P and NP patients' glomeruli, with absolute fold changes (FC) ≥1.5, p ≤ 0.05. Supervised classifier analysis (K nearest neighbor) identified a set of five proteins, including Gamma-butyrobetaine dioxygenase (BBOX1, O75936) and Cadherin 16 (CDH16, O75309), overexpressed in P, and Eosinophil peroxidase (EPX, P11678), DnaJ homolog subfamily B member 1 (DNAJB1, P25685) and Alpha-1-syntrophin (SNTA1, Q13424), overexpressed in NP glomeruli, correctly classifying 16/17 kidney biopsy samples. Geneset Enrichment Analysis (GSEA), showed that metabolic pathways were generally enriched in P, and structural cell pathways in NP. Pathway analysis identified Epithelial Adherens Junction Signaling as most affected canonical pathway. IHC analysis confirmed overexpression of BBOX1 and Cadherin 16 in glomeruli from P patients. In conclusion, glomerular proteomic profiling can be used to discriminate P from NP HN patients.

MO447: Glomerular Transcriptomics in IGA Nephropathy Differentiates Between Disease Progression and Stability in Low-Risk Patients After Prolonged Follow-Up

BACKGROUND AND AIMS

IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. We have previously shown that patients with assumed benign IgAN can develop progressive kidney failure, including end-stage kidney disease, after a sufficiently long follow-up period [1]. In the reported patient cohort [1], histological, clinical and laboratory findings at the time of diagnosis were unable to predict a subsequent stable or progressive disease course. Thus, we hypothesized that glomerular transcriptomics from the diagnostic kidney biopsy could help make this distinction.

METHOD

We included all progressive patients (n = 27) and patients with the stable or remitting disease (non-progressors, n = 42) from our previously reported cohort of adult patients with biopsy-proven and assumed benign IgAN (n = 192). Progression was defined as a ≥ 50% decline in eGFR from the diagnostic kidney biopsy, performed between 1988 and 1999 until follow-up examination [1]. The median follow-up time was 22 years. Glomerular cross-sections were obtained through laser-capture microdissection from archival kidney biopsy sections for RNA extraction and sequencing, using NovaSeq 6000 (Illumina, USA) at Functional Genomics Centre Zurich, Switzerland. Samples yielding insufficient sequencing quality were excluded, leaving n = 8 progressors and n = 9 non-progressors for analysis, using limma [2] and edgeR [3] in R Bioconductor.

RESULTS

In the first round of analysis, we identified 1818 differentially expressed genes (P ≤ 0.05, absolute fold change ≥ 2), of which 1562 genes were overrepresented in progressors and 256 genes were overrepresented in non-progressors. Principal component analysis and hierarchical cluster analysis revealed a separation between the two study groups, indicating that underlying transcriptomic differences are present many years prior to the overt manifestation of disease progression. Interestingly, in progressors, the nuclear factor-kappa B complex, linked to IgAN pathogenesis [4], was the most overabundant transcription factor and Fc Fragment of IgA Receptor (FCAR) was the most overrepresented differentially abundant mRNA. Ingenuity Pathway Analysis (Qiagen, USA) suggested an overrepresentation of the phagosome formation pathway (P = 3.09E-08, Z-score = 8.43), indicating phagosome activation in progressors, possibly a response to the observed FCAR overexpression. To identify potential markers for disease progression, we used an unsupervised K Nearest Neighbour analysis of 1818 differentially expressed genes, allowing combinations of ≤ 10 genes. A two-component classifier (APOL5 and ZXDC) performed best, classifying 15/17 samples correctly (sensitivity 75%, specificity 100%, accuracy 88.24%) on average 21 years prior to a manifested decrease in eGFR. Further refinements of the statistical analyses and confirmation studies are planned to substantiate our initial findings.

CONCLUSION

Glomerular mRNA sequencing performed at the time of diagnosis of assumed benign IgAN can differentiate between subsequent stable and progressive disease courses in the distant future. In our cohort, combining APOL5 and ZXDC can predict subsequent disease course with 88.24% accuracy already 21 years prior to the discovery of progression with conventional means.

Variable expression of eighteen common housekeeping genes in human non-cancerous kidney biopsies

Housekeeping, or reference genes (RGs) are, by definition, loci with stable expression profiles that are widely used as internal controls to normalize mRNA levels. However, due to specific events, such as pathological changes, or technical procedures, their expression might be altered, failing to fulfil critical normalization pre-requisites. To identify RG genes suitable as internal controls in human non-cancerous kidney tissue, we selected 18 RG candidates based on previous data and screen them in 30 expression datasets (>800 patients), including our own, publicly available or provided by independent groups. Datasets included specimens from patients with hypertensive and diabetic nephropathy, Fabry disease, focal segmental glomerulosclerosis, IgA nephropathy, membranous nephropathy, and minimal change disease. We examined both microdissected and whole section-based datasets. Expression variability of 4 candidate genes (YWHAZ, SLC4A1AP, RPS13 and ACTB) was further examined by qPCR in biopsies from patients with hypertensive nephropathy (n = 11) and healthy controls (n = 5). Only YWHAZ gene expression remained stable in all datasets whereas SLC4A1AP was stable in all but one Fabry dataset. All other RGs were differentially expressed in at least 2 datasets, and in 4.5 datasets on average. No differences in YWHAZ, SLC4A1AP, RPS13 and ACTB gene expression between hypertensive and control biopsies were detected by qPCR. Although RGs suitable to all techniques and tissues are unlikely to exist, our data suggest that in non-cancerous kidney biopsies expression of YWHAZ and SLC4AIAP genes is stable and suitable for normalization purposes.

Tenacibaculum sp. associated with winter ulcers in sea-reared Atlantic salmon Salmo salar

Coldwater-associated ulcers, i.e. winter ulcers, in seawater-reared Atlantic salmon Salmo salar L. have been reported in Norway since the late 1980s, and Moritella viscosa has been established as an important factor in the pathogenesis of this condition. As routine histopathological examination of winter ulcer cases in our laboratory revealed frequent presence in ulcers of long, slender rods clearly different from M. viscosa, a closer study focusing on these bacteria was conducted. Field cases of winter ulcers during 2 sampling periods, 1996 and 2004-2005, were investigated and long, slender rods were observed by histopathological examination in 70 and 62.5% of the ulcers examined, respectively, whereas cultivation on marine agar resulted in the isolation of yellow-pigmented colonies with long rods from 3 and 13% of the ulcers only. The isolates could be separated into 2 groups, both identified as belonging to the genus Tenacibaculum based on phenotypic characterization and 16S rRNA sequencing. Bath challenge for 7 h confirmed the ability of Group 1 bacterium to produce skin and cornea ulcers. In fish already suffering from M. viscosa-induced ulcers, co-infection with the Group 1 bacterium was established within 1 h. Ulcers from field cases of winter ulcers and from the transmission experiments tested positive by immunohistochemistry with polyclonal antiserum against the Group 1 bacterium but not the Group 2 bacterium. Our results strongly indicate the importance of the Group 1 bacterium in the pathogenesis of winter ulcers in Norway. The bacterium is difficult to isolate and is therefore likely to be underdiagnosed based on cultivation only.

Biofilms and type III secretion are not mutually exclusive in Pseudomonas aeruginosa

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen that causes acute and chronic infections in immunocompromised individuals. It is also a model organism for bacterial biofilm formation. Acute infections are often associated with planktonic or free-floating cells, high virulence and fast growth. Conversely, chronic infections are often associated with the biofilm mode of growth, low virulence and slow growth that resembles that of planktonic cells in stationary phase. Biofilm formation and type III secretion have been shown to be reciprocally regulated, and it has been suggested that factors related to acute infection may be incompatible with biofilm formation. In a previous proteomic study of the interrelationships between planktonic cells, colonies and continuously grown biofilms, we showed that biofilms under the growth conditions applied are more similar to planktonic cells in exponential phase than to those in stationary phase. In the current study, we investigated how these conditions influence the production of virulence factors using a transcriptomic approach. Our results show that biofilms express the type III secretion system, whereas planktonic cells do not. This was confirmed by the detection of PcrV in the cellular and secreted fractions of biofilms, but not in those of planktonic cells. We also detected the type III effector proteins ExoS and ExoT in the biofilm effluent, but not in the supernatants of planktonic cells. Biofilm formation and type III secretion are therefore not mutually exclusive in P. aeruginosa, and biofilms could play a more active role in virulence than previously thought.

Interrelationships between colonies, biofilms, and planktonic cells of Pseudomonas aeruginosa

Pseudomonas aeruginosa is a gram-negative bacterium and an opportunistic human pathogen that causes chronic infections in immunocompromised individuals. These infections are hard to treat, partly due to the high intrinsic resistance of the bacterium to clinically used antibiotics and partly due to the formation of antibiotic-tolerant biofilms. The three most common ways of growing bacteria in vitro are as planktonic cultures, colonies on agar plates, and biofilms in continuous-flow systems. Biofilms are known to express genes different from those of planktonic cells, and biofilm cells are generally believed to closely resemble planktonic cells in stationary phase. However, few, if any, studies have examined global gene expression in colonies. We used a proteomic approach to investigate the interrelationships between planktonic cells, colonies, and biofilms under comparable conditions. Our results show that protein profiles in colonies resemble those of planktonic cells. Furthermore, contrary to what has been reported previously, the protein profiles of biofilms were found to more closely resemble those of exponentially growing planktonic cells than those of planktonic cells in the stationary phase. These findings raise some intriguing questions about the true nature of biofilms.

Key parameters in sludge dewatering: testing for the shear sensitivity and EPS content

The fraction of extractable extracellular polymeric substances (EPS) and the shear sensitivity (k(ss)) are key parameters with respect to sludge dewatering, affecting the dry matter content of dewatered sludge and the dewatering rate and conditioner demand, respectively. Methods are described for determination of the two key parameters by use of the same laboratory test reactor. The implications of such characterisation with respect to dewatering are discussed based on examples of application to sludge processing and novel process development for sludge minimisation.

Identification and characterization of Carnobacteria isolated from fish intestine

Eleven bacterial strains were isolated from the gastrointestinal tract of four fish species, Atlantic salmon (Salmo salar L.), Arctic charr (Salvelinus alpinus L.), Atlantic cod (Gadus morhua L.) and wolffish (Anarhichas lupus L.). All the strains were Gram-positive rods, non-sporing, catalase and oxidase-negative, able to grow at pH 9.0 but not on acetate containing media (pH < or = 5.4), and were fermentative. They had a high content of oleic acid (18:1 n-9) in cellular lipid, and were found to belong to the genus Carnobacterium by phenotypic criteria. The eleven carnobacteria strains were further identified on the basis of 16S rDNA sequence analysis and AFLP(TM) fingerprinting.

Lactic acid bacteria associated with the digestive tract of Atlantic salmon (Salmo salar L.)

The present study reports the effect of excessive handling stress and starvation on the lactic acid bacteria associated with the digestive tract of Atlantic salmon (Salmo salar L.). A relatively low population level (approximately 2 x 103 bacteria per gram wet tissue) of viable adherent heterotrophic bacteria was associated with the digestive tract (foregut, midgut and hindgut). Of the 752 bacterial isolates isolated from diet, water and the digestive tract, 201 isolates belonged to the carnobacteria. Of these isolates, one from the diet, one from the rearing water and 80 from the gastrointestinal tract, were further identified on the basis of 16S rDNA sequence analysis. All these isolates were identified as being Carnobacterium piscicola-like. Daily repeated stress and starvation of the fish over 11 d had no influence on the total culturable bacterial numbers or population level of C. piscicola associated with the digestive tract. C. piscicola-like isolates colonizing the various intestinal regions (foregut, midgut and hindgut) were also screened for their ability to produce growth inhibitory compounds active against the fish pathogen Aeromonas salmonicida. Of the 199 C. piscicola isolates tested, 139 inhibited growth of the pathogen.

Dimensional assessment of onset of action of antidepressants: a comparative study of moclobemide vs. clomipramine in depressed patients with blunted affect and psychomotor retardation

The onset of action (during the first 2 weeks of treatment) of moclobemide (450 mg/day), a reversible MAO-A inhibitor, was compared in a double-blind, multi-center trial with clomipramine (150 mg/day) on dimensional and global depressive symptoms in 124 hospitalized patients suffering from a major depressive episode according to DSM-III-R criteria and with blunted affect and retardation. An earlier efficacy was found for moclobemide with significant treatment differences in favor of moclobemide, which were detected on negative symptoms (anhedonia, blunted affect and retardation) on days 7 and 10. The overall effect on depression at the end of the 4-week trial period was similar in both groups. However, a higher termination rate due to lack of efficacy was found with moclobemide (10 vs. 3). The tolerability was significantly better for moclobemide, as shown by the lower frequency of adverse events.

Moclobemide versus fluoxetine for double depression: a randomized double-blind study

The efficacy and tolerability of the selective reversible monoamine oxidase A inhibitor, moclobemide (300 mg/day) and the selective serotonin uptake inhibitor, fluoxetine (200 mg/day), were compared in a six-week single-centre double-blind fixed-dose study in patients (n = 42) with double depression (DSM-III-R: dysthymia with superimposed major depressive episode) using weekly assessment on the Hamilton depression rating scale (HDRS-17 items) and clinical global impression (CGI) scale. The primary efficacy outcome measure was a decrease > or = 50% in end of treatment HDRS score, secondary measures were the mean total endpoint HDRS scores and percentages of CGI very good and good responses. Tolerability was measured by the frequency and severity of volunteered adverse events. There were no significant differences in secondary efficacy outcome measures, but more patients achieved a > or = 50% decrease in HDRS score on moclobemide (71% vs 38%, p < 0.05). The only adverse event was mild transient anxiety (n = 1) with moclobemide. The results suggest that moclobemide and fluoxetine are equally well tolerated and at least similar in efficacy in double depression. Evidence that moclobemide may be more effective requires confirmation in a larger comparative study incorporating a placebo control group.

Antidepressants and drug-metabolizing enzymes--expert group report

Antidepressant drugs are extensively metabolized. Consequently, the biotransformation pattern of antidepressants has an important influence on their clinical properties, i.e., pharmacokinetics, toxicity, drug-drug interactions, side-effect profile and last but not least therapeutic efficacy. It was against this background that a multidisciplinary group of experts discussed the clinical relevance of the rapidly increasing body of knowledge of antidepressant-metabolizing enzymes. The variability of the response of a given individual to an antidepressant is determined genetically and by the environment. Genetic polymorphism of drug-metabolizing enzymes and inhibition by other substrates may affect the enzymatic biotransformation of antidepressants. In vitro assay techniques allow an estimation of the potential variability in clinical response to antidepressants and a reasonable prediction of the drug-drug interaction patterns. The results of in vitro tests should therefore be considered early in the development of an antidepressant as a background for designing clinical studies (treatment schedules and dosing). Physicians should have an understanding of the relevance of genetic polymorphism for clinical practice. Education is needed in order to fill the existing gaps in knowledge about antidepressant-enzyme interactions and their application in daily treatment practice. The information on potential drug interactions determined by genetic polymorphism and based on studies with enzymes should be increasingly contained in drug compendia.

Therapeutic efficacy of antidepressants in agitated anxious depression--a meta-analysis of moclobemide studies

The results of the meta-analysis of studies comparing the efficacy of moclobemide, imipramine and so-called sedative antidepressants (amitriptyline, mianserin and maprotiline) in 2416 patients are described. The results demonstrated that in agitated-anxious depressive patients (defined by HAMD factor score or HAMD item 9) a nonsedative, reversible MAO-A inhibitor moclobemide has about equal efficacy as imipramine or sedative antidepressants. All antidepressants were clearly superior to placebo, irrespective of the outcome measures applied (> 50% HAMD decrease, CGI improvement). The efficacy of antidepressants in agitated patients was unrelated to the severity of agitation and did not appear to be inferior to the efficacy in nonagitated patients. Comedication with benzodiazepines had no impact on overall efficacy of either moclobemide or other antidepressants in this patient population. Previous treatment with antidepressants, however, always negatively influenced the outcome with trial drugs, e.g., reduced their efficacy. Placebo response in agitated depressives appeared generally to be low (20-30%) and was clearly reduced with increased severity of agitation, irrespectively of how the agitation was defined.

Acute epiglottitis in a rural area: experiences with an anesthesiologist-staffed ambulance helicopter

The majority of fatalities due to acute epiglottitis (AE) result from prehospital airway problems. We reviewed the courses of 14 patients with AE treated by an aeromedical team consisting of an anesthesiologist and a paramedic. Eight patients were transported from a physician's office or from the patient's own home. One patient was intubated at the scene, and two received ventilatory support with mask and bag en route to the hospital. Two patients suffered cardiopulmonary arrest before arrival of the aeromedical team, both resulting in severe hypoxic encephalopathy. All six patients transported from hospitals were intubated prior to the helicopter transport. Based on our own experience and a review of the literature, we discuss prehospital airway management in this group of patients.

Effects of giving water 20-450 ml with oral diazepam premedication 1-2 h before operation

We have studied the volume of water which should accompany diazepam 10 mg oral premedication given 1-2 h before induction of anaesthesia in 75 patients undergoing elective gynaecological laparoscopy. Twenty-five patients were given 20 ml (group A), 25 patients 150 ml (group B), and 25 patients 300-450 ml of water (group C). There were no differences between the groups in gastric fluid volume and acidity. All groups reported a reduction in thirst and dryness of the mouth after water intake, while only group B reported significant anxiolysis. Eight patients in group C experienced augmented diuresis, compared with no patients in groups A and B. We conclude that 150 ml is the ideal amount of water given with oral premedication 1-2 h before anaesthesia.

Theoretical considerations and perspectives on the onset of action of moclobemide

The aim of this paper is to focus on methodological problems related to clinical studies on the onset of action of antidepressants, especially moclobemide. The methodological discussion proposed focuses on: --global efficacy as a function of time; --proposals for a specific approach to the study of the onset of action; --quality of the response and onset of action; --the dimensional level and the onset of action.

Efficacy and tolerability of moclobemide compared with fluvoxamine in depressive disorder (DSM III). A French/Swiss double-blind trial

The efficacy and tolerability of moclobemide and fluvoxamine, two new types of antidepressant agents, were compared in a multicentre, double-blind prospective study of patients with a diagnosis of major depressive episode (DSM III). Patients were randomized to receive either moclobemide (150 mg) or fluvoxamine (50 mg) twice daily for 7 days, immediately following a washout period of at least 1 week. Dosages were increased where necessary on day 8, to a maximum of moclobemide 450 mg or fluvoxamine 200 mg and in most cases were maintained at these levels for the remainder of the study period (4-6 weeks). Both treatment groups showed a marked antidepressant effect. While both treatments were well tolerated, moclobemide showed a more favourable side-effect profile than fluvoxamine. Of the 126 patients eligible for evaluation, 34 withdrew from therapy, 22% in the moclobemide group and 30% in the fluvoxamine group. Adverse events were reported in 41.8% of patients treated with moclobemide compared to 60.3% of patients in the fluvoxamine group. Reports of dry mouth and other anticholinergic effects were more frequent among those treated with fluvoxamine. A greater number of gastrointestinal complaints, especially nausea, also occurred in the fluvoxamine-treated patients.

Macrophages and mast cells in dystrophic masseter muscle: a light and electron microscopic study

Macrophages and mast cells in masseter muscle from normal and dystrophic mice were studied by light and electron microscopy. Acid phosphatase activity and FITC-dextran were used to identify and describe macrophages. Toluidine blue was used as a marker for mast cells. In dystrophic muscle, the number of macrophages was greatly increased and they contained large amounts of phagocytozed material. In normal muscle, mast cells were rarely identified whereas dystrophic muscle contained many mast cells which were often in close contact with macrophages.

Electron microscopic and histochemical studies on dystrophic masseter muscle

Masseter muscles from normal and dystrophic mice were investigated with the electron microscope and by the use of histochemical techniques for myosin ATPase and succinic dehydrogenase activity. The observations show that the muscle fibers are severely affected in the masseter of the dystrophic mouse.

4,5,6,7-Tetrahydroisothiazolo[5,4-c]pyridin-3-ol and related analogues of THIP. Synthesis and biological activity

The thio analogues of the GABA (gamma-aminobutyric acid) agonist THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol), the GABA uptake inhibitor THPO (4,5,6,7-tetrahydroisoxazolo[4,5-c]pyridin-3-ol), and the glycine antagonist THAZ (5,6,7,8-tetrahydro-4H-isoxazolo[4,5-d]azepin-3-ol) have been synthesized and tested biologically on single neurons in the cat spinal cord and in vitro by using synaptic membrane preparations obtained from rat brains. In contrast to THIP, thio-THIP (4,5,6,7-tetrahydroisothiazolo[5,4-c]pyridin-3-ol, 5) was only a weak GABA agonist. Thio-THPO (4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridin-3-ol, 10) was slightly weaker than THPO as an inhibitor of GABA uptake in vitro, and these two compounds were approximately equipotent in enhancing the inhibition of the firing of cat spinal neurons by GABA. Like THAZ and structurally related bicyclic isoxazole zwitterions, thio-THAZ (5,6,7,8-tetrahydro-4H-isothiazolo[4,5-d]azepin-3-ol, 15) was an antagonist at glycine receptors on cat spinal neurons. The I/U ratios, which reflect the ability of neutral amino acids to penetrate the blood-brain barrier (BBB), were calculated for 5 (I/U = 16), 10 (63), and 15 (200). These low I/U ratios, compared with the findings that THIP (I/U = 500 or 1500) and THPO (I/U = 2500) enter the brain after systemic administration, suggest that the thio analogues may penetrate the BBB very easily.

Local reactions after i.v. injections of diazepam, flunitrazepam and isotonic saline

Local reactions after i.v. injection of diazepam, flunitrazepam and isotonic saline were studied in patients who received extradural analgesia or general anaesthesia. The frequency of thrombophlebitis on the 1st, 3rd and 5th days after the injection of diazepam was 2.1%, 17.0% and 14.9% respectively, after flunitrazepam 10.0%. 10.0% and 14.0%, and after saline 0%, 6.7% and 4.4%. The differences between the groups were not statistically significant (P > 0.05). One month after the injection 15.6% in the diazepam group, 8.5% in the flunitrazepam group and 9.3% in the saline group had pain or tenderness in the arm used for the injection.

Hypersensitivity reactions to food colours with special reference to the natural colour annatto extract (butter colour)

It is well known that synthetic food colours especially some azo dyes can provoke hypersensitivity reactions such as urticaria, angioneurotic oedema, and astma (Michaëlsson and Juhlin, 1973, Granholt and Thune, 1975). Natural food colours are scarcely investigated with respect to potential allergic properties. Annatto extract, a commonly used food colour in edible fats e.g. butter, has been tested in patients. Among 61 consecutive patients suffereing from chornic urticaria and/or angioneurotic oedema 56 patients were orally provoked by annatto extract during elimination diet. Challenge was performed with a dose equivalent to the amount used in 25 grammes of butter. Twentysix per cent of the patients reacted to this colour 4 hours (SD: 2,6) after intake. Similar challenges with synthetic dyes showed the following results: Tartrazine 11%, Sunset Yellow FCF 17%, Food Red 17 16%, Amaranth 9%, Ponceau 4 R 15%, Erythrosine 12% and Brillant Blue FCF 14%. The present study indicates that natural food colours may induce hypersensitivity reactions as frequent as synthetic dyes.

On the effect of vinblastine on ameloblasts of rat incisors in vivo. 2. Protracted effect on secretory ameloblasts. A light microscopical study

The effects of vinblastine sulphate at a dosage of 0.2 mg per 100 g body weight on the secretory ameloblasts of rat incisors were studied 3, 6 and 24 hours and 3 and 7 days after administration of the drug. The vinblastine affected the secretion profoundly, caused a reduction in size of the cells and death of many ameloblasts. Most of the surviving ameloblasts restored initially-induced loss of polarity. Many also resumed secretion and deposition of enamel matrix. The Tomes' processess were extremely sensitive to vinblastine and all matrix deposited after administration of the drug appeared abnormal in structure. Ameloblasts not resuming secretory activity were less than half the size (height) of normal cells. In some areas all the ameloblasts were destroyed with the exception of a varying number of surviving ameloblasts parts consisting only of a nucleus and a small amount of cytoplasm. The ameloblasts which had re-established secretory activity, and most of the ameloblasts which had not, retained their ability to transform into transporting ameloblasts. Large amounts of ameloblast debris present 3 and 6 hours after administration of the vinblastine were effectively engulfed and digested by the cells of the striatum intermedium within 24 hours.

Light microscopical and ultrastructural observations on the effect of vinblastine on ameloblasts of rat incisors in vivo. I. Short-term effect on secretory ameloblasts

The highly polarized secretory ameloblasts in the incisors of rats fixed by perfusion with glutaraldehyde two or three hours after intravenous administration of vinblastine sulfate at a dosage of 5 mg per 100 g body weight were studied in the light microscope and the electron microscope. The following effects were observed: 1. All cytoplasmic microtubules in the ameloblasts had vanished. This was not accompanied by the appearance of paracrystals of microtubular protein or macrotubules. 2. The ameloblasts preserved their external features of polarized cells but lost their ability to maintain normal orderly segregation of the cell constituents; i.e. their normal internal compartmentalization and polarity had vanished. 3. The ameloblasts lost their capability of directional translocation of the secretory granules towards the cell apex. 4. Secretory granules already translocated to the cell apex regurgitated in the cell and a probably delayed discharge of secretory material had started in abnormal site at the surface. 5. The normal arrangement of ribosomes into polyribosomes on the membranes of the rough endoplasmic reticulum was no longer present; the ribosomes were apparently distributed at random. 6. New secretion was inhibited or brought to a standstill but secretory material already present in the Golgi complex appeared to be transported normally. 7. The centriole had started to develop into a cilium in many of the cells. 8. The number of autophagic vacuoles had increased.